Erika Hutt-Centeno, MD

A 40-year-old woman with a history of hypertension, who was recently started on a diuretic, presents to the emergency department after a witnessed syncopal event. She reports a prodrome of lightheadedness, nausea, and darkening of her vision that occurred a few seconds after standing, followed by loss of consciousness. She had a complete, spontaneous recovery after 10 seconds, but upon arousal she noticed she had lost bladder control.

Her blood pressure is 120/80 mm Hg supine, 110/70 mm Hg sitting, and 90/60 mm Hg standing. She has no focal neurologic deficits. The cardiac examination is normal, without murmurs, and electrocardiography shows sinus tachycardia (heart rate 110 bpm) without other abnormalities. Results of laboratory testing are unremarkable.

Should you order neuroimaging to evaluate for syncope?

DEFINITIONS, CLASSIFICATIONS

Syncope is an abrupt loss of consciousness due to transient global cerebral hypoperfusion, with a concomitant loss of postural tone and rapid, spontaneous recovery.¹ Recovery from syncope is characterized by immediate restoration of orientation and normal behavior, although the period after recovery may be accompanied by fatigue.²

The European Society of Cardiology² has classified syncope into 3 main categories: reflex (neurally mediated) syncope, syncope due to orthostatic hypotension, and cardiac syncope. Determining the cause is critical, as this determines the prognosis.

KEYS TO THE EVALUATION

According to the 2017 American College of Cardiology/American Heart Association (ACC/AHA) and the 2009 European Society of Cardiology guidelines, the evaluation of syncope should include a thorough history, taken from the patient and witnesses, and a complete physical examination. This can identify the cause of syncope in up to 50% of cases and differentiate between cardiac and noncardiac causes. Features that point to cardiac syncope include age older than 60, male sex, known heart disease, brief prodrome, syncope during exertion or when supine, first syncopal event, family history of sudden cardiac death, and abnormal physical examination.¹

Features that suggest noncardiac syncope are young age; syncope only when standing; recurrent syncope; a prodrome of nausea, vomiting, and a warm sensation; and triggers such as dehydration, pain, distressful stimulus, cough, laugh micturition, defecation, and swallowing.¹

Electrocardiography should follow the history and physical examination. When done at presentation, electrocardiography is diagnostic in only about 5% of cases. However, given the importance of the diagnosis, it remains an essential part of the initial evaluation of syncope.³

If a clear cause of syncope is identified at this point, no further workup is needed, and the cause of syncope should be addressed.¹ If the cause is still unclear, the ACC/AHA guidelines recommend further evaluation based on the clinical presentation and risk stratification.

 

 

WHEN TO PURSUE ADDITIONAL TESTING

Routine use of additional testing is costly; tests should be ordered on the basis of their potential diagnostic and prognostic value. Additional evaluation should follow a stepwise approach and can include targeted blood work, autonomic nerve evaluation, tilt-table testing, transthoracic echocardiography, stress testing, electrocardiographic monitoring, and electrophysiologic testing.¹

If the initial evaluation indicates cardiac syncope (Table 1), evaluation with echocardiography has a class IIa recommendation (considered reasonable).^1,2

Syncope is rarely a manifestation of neurologic disease, yet 11% to 58% of patients with a first episode of uncomplicated syncope undergo extensive neuroimaging with magnetic resonance imaging, computed tomography, electroencephalography (EEG), and carotid ultrasonography.⁴ Evidence suggests that routine neurologic testing is of limited value given its low diagnostic yield and high cost.

Epilepsy is the most common neurologic cause of loss of consciousness but is estimated to account for less than 5% of patients with syncope.⁵ A thorough and thoughtful neurologic history and examination is often enough to distinguish between syncope, convulsive syncope, epileptic convulsions, and pseudosyncope.

In syncope, the loss of consciousness usually occurs 30 seconds to several minutes after standing. It presents with or without a prodrome (warmth, palpitations, and diaphoresis) and can be relieved with supine positioning. True loss of consciousness usually lasts less than a minute and is accompanied by loss of postural tone, with little or no fatigue in the recovery period.⁶

Conversely, in convulsive syncope, the prodrome can include pallor and diaphoresis. Loss of consciousness lasts about 30 seconds but is accompanied by fixed gaze, upward eye deviation, nuchal rigidity, tonic spasms, myoclonic jerks, tonic-clonic convulsions, and oral automatisms.⁶

Pseudosyncope is characterized by a prodrome of lightheadedness, shortness of breath, chest pain, and tingling sensations, followed by episodes of apparent loss of consciousness that last longer than several minutes and occur multiple times a day. During these episodes, patients purposefully try to avoid trauma when they lose consciousness, and almost always keep their eyes closed, in contrast to syncopal episodes, when the eyes are open and glassy.⁷

ROLE OF ELECTROENCEPHALOGRAPHY

If the diagnosis remains unclear after the history and neurologic examination, EEG is recommended (class IIa, ie, reasonable, can be useful) during tilt-table testing, as it can help differentiate syncope, pseudosyncope, and epilepsy.¹

In an epileptic convulsion, EEG shows epileptiform discharges, whereas in syncope, it shows diffuse brainwave slowing with delta waves and a flatline pattern. In pseudosyncope and psychogenic nonepileptic seizures, EEG shows normal activity.⁸

Routine EEG is not recommended if there are no specific neurologic signs of epilepsy or if the history and neurologic examination indicate syncope or pseudosyncope.¹

Structural brain disease does not typically present with transient global cerebral hypoperfusion resulting in syncope, so magnetic resonance imaging and computed tomography have a low diagnostic yield. Studies have revealed that for the 11% to 58% of patients who undergo neuroimaging, it establishes a diagnosis in only 0.2% to 1%.⁹ For this reason and in view of their high cost, these imaging tests should not be routinely ordered in the evaluation of syncope.^4,10 Similarly, carotid artery imaging should not be routinely ordered if there is no focal neurologic finding suggesting unilateral ischemia.¹⁰

CASE CONTINUED

In our 40-year-old patient, the history suggests dehydration, as she recently started taking a diuretic. Thus, laboratory testing is reasonable.

Loss of bladder control is often interpreted as a red flag for neurologic disease, but syncope can often present with urinary incontinence. Urinary incontinence may also occur in epileptic seizure and in nonepileptic events such as syncope. A pooled analysis by Brigo et al¹¹ determined that urinary incontinence had no value in distinguishing between epilepsy and syncope. Therefore, this physical finding should not incline the clinician to one diagnosis or the other.


Given our patient’s presentation, findings on physical examination, and absence of focal neurologic deficits, she should not undergo neuroimaging for syncope evaluation. The more likely cause of her syncope is orthostatic intolerance (orthostatic hypotension or vasovagal syncope) in the setting of intravascular volume depletion, likely secondary to diuretic use. Obtaining orthostatic vital signs is mandatory, and this confirms the diagnosis.

A 40-year-old woman with a history of hypertension, who was recently started on a diuretic, presents to the emergency department after a witnessed syncopal event. She reports a prodrome of lightheadedness, nausea, and darkening of her vision that occurred a few seconds after standing, followed by loss of consciousness. She had a complete, spontaneous recovery after 10 seconds, but upon arousal she noticed she had lost bladder control.

Her blood pressure is 120/80 mm Hg supine, 110/70 mm Hg sitting, and 90/60 mm Hg standing. She has no focal neurologic deficits. The cardiac examination is normal, without murmurs, and electrocardiography shows sinus tachycardia (heart rate 110 bpm) without other abnormalities. Results of laboratory testing are unremarkable.

Should you order neuroimaging to evaluate for syncope?

DEFINITIONS, CLASSIFICATIONS

Syncope is an abrupt loss of consciousness due to transient global cerebral hypoperfusion, with a concomitant loss of postural tone and rapid, spontaneous recovery.¹ Recovery from syncope is characterized by immediate restoration of orientation and normal behavior, although the period after recovery may be accompanied by fatigue.²

The European Society of Cardiology² has classified syncope into 3 main categories: reflex (neurally mediated) syncope, syncope due to orthostatic hypotension, and cardiac syncope. Determining the cause is critical, as this determines the prognosis.

KEYS TO THE EVALUATION

According to the 2017 American College of Cardiology/American Heart Association (ACC/AHA) and the 2009 European Society of Cardiology guidelines, the evaluation of syncope should include a thorough history, taken from the patient and witnesses, and a complete physical examination. This can identify the cause of syncope in up to 50% of cases and differentiate between cardiac and noncardiac causes. Features that point to cardiac syncope include age older than 60, male sex, known heart disease, brief prodrome, syncope during exertion or when supine, first syncopal event, family history of sudden cardiac death, and abnormal physical examination.¹

Features that suggest noncardiac syncope are young age; syncope only when standing; recurrent syncope; a prodrome of nausea, vomiting, and a warm sensation; and triggers such as dehydration, pain, distressful stimulus, cough, laugh micturition, defecation, and swallowing.¹

Electrocardiography should follow the history and physical examination. When done at presentation, electrocardiography is diagnostic in only about 5% of cases. However, given the importance of the diagnosis, it remains an essential part of the initial evaluation of syncope.³

If a clear cause of syncope is identified at this point, no further workup is needed, and the cause of syncope should be addressed.¹ If the cause is still unclear, the ACC/AHA guidelines recommend further evaluation based on the clinical presentation and risk stratification.

 

 

WHEN TO PURSUE ADDITIONAL TESTING

Routine use of additional testing is costly; tests should be ordered on the basis of their potential diagnostic and prognostic value. Additional evaluation should follow a stepwise approach and can include targeted blood work, autonomic nerve evaluation, tilt-table testing, transthoracic echocardiography, stress testing, electrocardiographic monitoring, and electrophysiologic testing.¹

If the initial evaluation indicates cardiac syncope (Table 1), evaluation with echocardiography has a class IIa recommendation (considered reasonable).^1,2

Syncope is rarely a manifestation of neurologic disease, yet 11% to 58% of patients with a first episode of uncomplicated syncope undergo extensive neuroimaging with magnetic resonance imaging, computed tomography, electroencephalography (EEG), and carotid ultrasonography.⁴ Evidence suggests that routine neurologic testing is of limited value given its low diagnostic yield and high cost.

Epilepsy is the most common neurologic cause of loss of consciousness but is estimated to account for less than 5% of patients with syncope.⁵ A thorough and thoughtful neurologic history and examination is often enough to distinguish between syncope, convulsive syncope, epileptic convulsions, and pseudosyncope.

In syncope, the loss of consciousness usually occurs 30 seconds to several minutes after standing. It presents with or without a prodrome (warmth, palpitations, and diaphoresis) and can be relieved with supine positioning. True loss of consciousness usually lasts less than a minute and is accompanied by loss of postural tone, with little or no fatigue in the recovery period.⁶

Conversely, in convulsive syncope, the prodrome can include pallor and diaphoresis. Loss of consciousness lasts about 30 seconds but is accompanied by fixed gaze, upward eye deviation, nuchal rigidity, tonic spasms, myoclonic jerks, tonic-clonic convulsions, and oral automatisms.⁶

Pseudosyncope is characterized by a prodrome of lightheadedness, shortness of breath, chest pain, and tingling sensations, followed by episodes of apparent loss of consciousness that last longer than several minutes and occur multiple times a day. During these episodes, patients purposefully try to avoid trauma when they lose consciousness, and almost always keep their eyes closed, in contrast to syncopal episodes, when the eyes are open and glassy.⁷

ROLE OF ELECTROENCEPHALOGRAPHY

If the diagnosis remains unclear after the history and neurologic examination, EEG is recommended (class IIa, ie, reasonable, can be useful) during tilt-table testing, as it can help differentiate syncope, pseudosyncope, and epilepsy.¹

In an epileptic convulsion, EEG shows epileptiform discharges, whereas in syncope, it shows diffuse brainwave slowing with delta waves and a flatline pattern. In pseudosyncope and psychogenic nonepileptic seizures, EEG shows normal activity.⁸

Routine EEG is not recommended if there are no specific neurologic signs of epilepsy or if the history and neurologic examination indicate syncope or pseudosyncope.¹

Structural brain disease does not typically present with transient global cerebral hypoperfusion resulting in syncope, so magnetic resonance imaging and computed tomography have a low diagnostic yield. Studies have revealed that for the 11% to 58% of patients who undergo neuroimaging, it establishes a diagnosis in only 0.2% to 1%.⁹ For this reason and in view of their high cost, these imaging tests should not be routinely ordered in the evaluation of syncope.^4,10 Similarly, carotid artery imaging should not be routinely ordered if there is no focal neurologic finding suggesting unilateral ischemia.¹⁰

CASE CONTINUED

In our 40-year-old patient, the history suggests dehydration, as she recently started taking a diuretic. Thus, laboratory testing is reasonable.

Loss of bladder control is often interpreted as a red flag for neurologic disease, but syncope can often present with urinary incontinence. Urinary incontinence may also occur in epileptic seizure and in nonepileptic events such as syncope. A pooled analysis by Brigo et al¹¹ determined that urinary incontinence had no value in distinguishing between epilepsy and syncope. Therefore, this physical finding should not incline the clinician to one diagnosis or the other.


Given our patient’s presentation, findings on physical examination, and absence of focal neurologic deficits, she should not undergo neuroimaging for syncope evaluation. The more likely cause of her syncope is orthostatic intolerance (orthostatic hypotension or vasovagal syncope) in the setting of intravascular volume depletion, likely secondary to diuretic use. Obtaining orthostatic vital signs is mandatory, and this confirms the diagnosis.

A 40-year-old woman with a history of hypertension, who was recently started on a diuretic, presents to the emergency department after a witnessed syncopal event. She reports a prodrome of lightheadedness, nausea, and darkening of her vision that occurred a few seconds after standing, followed by loss of consciousness. She had a complete, spontaneous recovery after 10 seconds, but upon arousal she noticed she had lost bladder control.

Her blood pressure is 120/80 mm Hg supine, 110/70 mm Hg sitting, and 90/60 mm Hg standing. She has no focal neurologic deficits. The cardiac examination is normal, without murmurs, and electrocardiography shows sinus tachycardia (heart rate 110 bpm) without other abnormalities. Results of laboratory testing are unremarkable.

Should you order neuroimaging to evaluate for syncope?

DEFINITIONS, CLASSIFICATIONS

Syncope is an abrupt loss of consciousness due to transient global cerebral hypoperfusion, with a concomitant loss of postural tone and rapid, spontaneous recovery.¹ Recovery from syncope is characterized by immediate restoration of orientation and normal behavior, although the period after recovery may be accompanied by fatigue.²

The European Society of Cardiology² has classified syncope into 3 main categories: reflex (neurally mediated) syncope, syncope due to orthostatic hypotension, and cardiac syncope. Determining the cause is critical, as this determines the prognosis.

KEYS TO THE EVALUATION

According to the 2017 American College of Cardiology/American Heart Association (ACC/AHA) and the 2009 European Society of Cardiology guidelines, the evaluation of syncope should include a thorough history, taken from the patient and witnesses, and a complete physical examination. This can identify the cause of syncope in up to 50% of cases and differentiate between cardiac and noncardiac causes. Features that point to cardiac syncope include age older than 60, male sex, known heart disease, brief prodrome, syncope during exertion or when supine, first syncopal event, family history of sudden cardiac death, and abnormal physical examination.¹

Features that suggest noncardiac syncope are young age; syncope only when standing; recurrent syncope; a prodrome of nausea, vomiting, and a warm sensation; and triggers such as dehydration, pain, distressful stimulus, cough, laugh micturition, defecation, and swallowing.¹

Electrocardiography should follow the history and physical examination. When done at presentation, electrocardiography is diagnostic in only about 5% of cases. However, given the importance of the diagnosis, it remains an essential part of the initial evaluation of syncope.³

If a clear cause of syncope is identified at this point, no further workup is needed, and the cause of syncope should be addressed.¹ If the cause is still unclear, the ACC/AHA guidelines recommend further evaluation based on the clinical presentation and risk stratification.

 

 

WHEN TO PURSUE ADDITIONAL TESTING

Routine use of additional testing is costly; tests should be ordered on the basis of their potential diagnostic and prognostic value. Additional evaluation should follow a stepwise approach and can include targeted blood work, autonomic nerve evaluation, tilt-table testing, transthoracic echocardiography, stress testing, electrocardiographic monitoring, and electrophysiologic testing.¹

If the initial evaluation indicates cardiac syncope (Table 1), evaluation with echocardiography has a class IIa recommendation (considered reasonable).^1,2

Syncope is rarely a manifestation of neurologic disease, yet 11% to 58% of patients with a first episode of uncomplicated syncope undergo extensive neuroimaging with magnetic resonance imaging, computed tomography, electroencephalography (EEG), and carotid ultrasonography.⁴ Evidence suggests that routine neurologic testing is of limited value given its low diagnostic yield and high cost.

Epilepsy is the most common neurologic cause of loss of consciousness but is estimated to account for less than 5% of patients with syncope.⁵ A thorough and thoughtful neurologic history and examination is often enough to distinguish between syncope, convulsive syncope, epileptic convulsions, and pseudosyncope.

In syncope, the loss of consciousness usually occurs 30 seconds to several minutes after standing. It presents with or without a prodrome (warmth, palpitations, and diaphoresis) and can be relieved with supine positioning. True loss of consciousness usually lasts less than a minute and is accompanied by loss of postural tone, with little or no fatigue in the recovery period.⁶

Conversely, in convulsive syncope, the prodrome can include pallor and diaphoresis. Loss of consciousness lasts about 30 seconds but is accompanied by fixed gaze, upward eye deviation, nuchal rigidity, tonic spasms, myoclonic jerks, tonic-clonic convulsions, and oral automatisms.⁶

Pseudosyncope is characterized by a prodrome of lightheadedness, shortness of breath, chest pain, and tingling sensations, followed by episodes of apparent loss of consciousness that last longer than several minutes and occur multiple times a day. During these episodes, patients purposefully try to avoid trauma when they lose consciousness, and almost always keep their eyes closed, in contrast to syncopal episodes, when the eyes are open and glassy.⁷

ROLE OF ELECTROENCEPHALOGRAPHY

If the diagnosis remains unclear after the history and neurologic examination, EEG is recommended (class IIa, ie, reasonable, can be useful) during tilt-table testing, as it can help differentiate syncope, pseudosyncope, and epilepsy.¹

In an epileptic convulsion, EEG shows epileptiform discharges, whereas in syncope, it shows diffuse brainwave slowing with delta waves and a flatline pattern. In pseudosyncope and psychogenic nonepileptic seizures, EEG shows normal activity.⁸

Routine EEG is not recommended if there are no specific neurologic signs of epilepsy or if the history and neurologic examination indicate syncope or pseudosyncope.¹

Structural brain disease does not typically present with transient global cerebral hypoperfusion resulting in syncope, so magnetic resonance imaging and computed tomography have a low diagnostic yield. Studies have revealed that for the 11% to 58% of patients who undergo neuroimaging, it establishes a diagnosis in only 0.2% to 1%.⁹ For this reason and in view of their high cost, these imaging tests should not be routinely ordered in the evaluation of syncope.^4,10 Similarly, carotid artery imaging should not be routinely ordered if there is no focal neurologic finding suggesting unilateral ischemia.¹⁰

CASE CONTINUED

In our 40-year-old patient, the history suggests dehydration, as she recently started taking a diuretic. Thus, laboratory testing is reasonable.

Loss of bladder control is often interpreted as a red flag for neurologic disease, but syncope can often present with urinary incontinence. Urinary incontinence may also occur in epileptic seizure and in nonepileptic events such as syncope. A pooled analysis by Brigo et al¹¹ determined that urinary incontinence had no value in distinguishing between epilepsy and syncope. Therefore, this physical finding should not incline the clinician to one diagnosis or the other.


Given our patient’s presentation, findings on physical examination, and absence of focal neurologic deficits, she should not undergo neuroimaging for syncope evaluation. The more likely cause of her syncope is orthostatic intolerance (orthostatic hypotension or vasovagal syncope) in the setting of intravascular volume depletion, likely secondary to diuretic use. Obtaining orthostatic vital signs is mandatory, and this confirms the diagnosis.

When treating high blood pressure, how low should we try to go? Debate continues about optimal blood pressure goals after publication of guidelines from the American College of Cardiology and American Heart Association (ACC/AHA) in 2017 that set or permitted a treatment goal of less than 130 mm Hg, depending on the population.¹

In this article, we summarize the evolution of hypertension guidelines and the evidence behind them.

HOW THE GOALS EVOLVED

JNC 7, 2003: 140/90 or 130/80

The seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7),² published in 2003, specified treatment goals of:

• < 140/90 mm Hg for most patients
• < 130/80 mm Hg for those with diabetes or chronic kidney disease.

JNC 7 defined hypertension as 140/90 mm Hg or higher, and introduced the classification of prehypertension for patients with a systolic blood pressure of 120 to 139 mm Hg or a diastolic blood pressure of 80 to 89 mm Hg. It advocated managing systolic hypertension in patients over age 50. It also recommended lifestyle changes such as the Dietary Approaches to Stop Hypertension (DASH) diet, moderate alcohol consumption, weight loss, and a physical activity plan.

JNC 7 provided much-needed clarity and uniformity to managing hypertension. Since then, various scientific groups have published their own guidelines (Table 1).^1–9

ACC/AHA/CDC 2014: 140/90

In 2014, the ACC, AHA, and US Centers for Disease Control and Prevention (CDC) published an evidence-based algorithm for hypertension management.³ As in JNC 7, they suggested a blood pressure goal of less than 140/90 mm Hg, lifestyle modification, and polytherapy, eg, a thiazide diuretic for stage 1 hypertension (< 160/100 mm Hg) and combination therapy with a thiazide diuretic and an angiotensin-converting enzyme (ACE) inhibitor, angiotensin II receptor blocker (ARB), or calcium channel blocker for stage 2 hypertension (≥ 160/100 mm Hg).

JNC 8 2014: 140/90 or 150/90

Soon after, the much-anticipated report of the panel members appointed to the eighth JNC (JNC 8) was published.⁴ Previous JNC reports were written and published under the auspices of the National Heart, Lung, and Blood Institute, but while the JNC 8 report was being prepared, this government body announced it would no longer publish guidelines.

In contrast to JNC 7, the JNC 8 panel based its recommendations on a systematic review of randomized clinical trials. However, the process and methodology were controversial, especially as the panel excluded some important clinical trials from the analysis.

JNC 8 relaxed the targets in several subgroups, such as patients over age 60 and those with diabetes and chronic kidney disease, due to a lack of definitive evidence on the impact of blood pressure targets lower than 140/90 mm Hg in these groups. Thus, their goals were:

• < 140/90 mm Hg for patients under age 60
• < 150/90 mm Hg for patients age 60 and older.

Table 2 shows the differences in recommendations between JNC 7 and JNC 8.

Of note, a minority of the JNC 8 panel disagreed with the new targets and provided evidence for keeping the systolic blood pressure target below 140 mm Hg for patients 60 and older.⁵ Further, the JNC 8 report was not endorsed by several important societies, ie, the AHA, ACC, National Heart, Lung, and Blood Institute, and American Society of Hypertension (ASH). These issues compromised the acceptance and applicability of the guidelines.

ASH/ISH 2014: 140/90 or 150/90

Also in 2014, the ASH and the International Society of Hypertension released their own report.⁶ Their goals:

• < 140/90 mm Hg for most patients
• < 150/90 mm Hg for patients age 80 and older.

AHA/ACC/ASH 2015: Goals in subgroups

In 2015, the AHA, ACC, and ASH released a joint scientific statement outlining hypertension goals for specific patient populations⁷:

• < 150/90 mm Hg for those age 80 and older
• < 140/90 mm Hg for those with coronary artery disease
• < 130/80 mm Hg for those with comorbidities such as diabetes and cardiovascular disease.

ADA 2016: Goals for patients with diabetes

In 2016, the American Diabetes Association (ADA) set the following blood pressure goals for patients with diabetes⁸:

• < 140/90 mm Hg for adults with diabetes
• < 130/80 mm Hg for younger adults with diabetes and adults with a high risk of cardiovascular disease
• 120–160/80–105 mm Hg for pregnant patients with diabetes and preexisting hypertension who are treated with antihypertensive therapy.

 

 

ACP/AAFP 2017: Systolic 150 or 130

In 2017, the American College of Physicians (ACP) and the American Academy of Family Physicians (AAFP) recommended a relaxed systolic blood pressure target, ie, below 150 mm Hg, for adults over age 60, but a tighter goal of less than 140 mm Hg for the same age group if they have transient ischemic attack, stroke, or high cardiovascular risk.⁹

ACC/AHA 2017: 130/80

The 2017 ACC/AHA guidelines recommended a more aggressive goal of below 130/80 for all, including patients age 65 and older.¹

This is a class I (strong) recommendation for patients with known cardiovascular disease or a 10-year risk of a cardiovascular event of 10% or higher, with a B-R level of evidence for the systolic goal (ie, moderate-quality, based on systematic review of randomized controlled trials) and a C-EO level of evidence for the diastolic goal (ie, based on expert opinion).

For patients who do not have cardiovascular disease and who are at lower risk of it, this is a class IIb (weak) recommendation, ie, it “may be reasonable,” with a B-NR level of evidence (moderate-quality, based on nonrandomized studies) for the systolic goal and C-EO (expert opinion) for the diastolic goal.

For many patients, this involves drug treatment. For those with known cardiovascular disease or a 10-year risk of an atherosclerotic cardiovascular disease event of 10% or higher, the ACC/AHA guidelines say that drug treatment “is recommended” if their average blood pressure is 130/80 mm Hg or higher (class I recommendation, based on strong evidence for the systolic threshold and expert option for the diastolic). For those without cardiovascular disease and at lower risk, drug treatment is recommended if their average blood pressure is 140/90 mm Hg or higher (also class I, but based on limited data).

EVERYONE AGREES ON LIFESTYLE

Although the guidelines differ in their blood pressure targets, they consistently recommend lifestyle modifications.

Lifestyle modifications, first described in JNC 7, included weight loss, sodium restriction, and the DASH diet, which is rich in fruits, vegetables, low-fat dairy products, whole grains, poultry, and fish, and low in red meat, sweets, cholesterol, and total and saturated fat.²

These recommendations were based on results from 3 large randomized controlled trials in patients with and without hypertension.^10–12 In patients with no history of hypertension, interventions to promote weight loss and sodium restriction significantly reduced blood pressure and the incidence of hypertension (the latter by as much as 77%) compared with usual care.^10,11

In patients with and without hypertension, lowering sodium intake in conjunction with the DASH diet was associated with substantially larger reductions in systolic blood pressure.¹²

The recommendation to lower sodium intake has not changed in the guideline revisions. Meanwhile, other modifications have been added, such as incorporating both aerobic and resistance exercise and moderating alcohol intake. These recommendations have a class I level of evidence (ie, strongest level) in the 2017 ACC/AHA guidelines.¹

HYPERTENSION BEGINS AT 130/80

The definition of hypertension changed in the 2017 ACC/AHA guidelines¹: previously set at 140/90 mm Hg or higher, it is now 130/80 mm Hg or higher for all age groups. Adults with systolic blood pressure of 130 to 139 mm Hg or diastolic blood pressure of 80 to 89 mm Hg are now classified as having stage 1 hypertension.

Under the new definition, the number of US adults who have hypertension expanded to 45.6% of the general population,¹³ up from 31.9% under the JNC 7 definition. Thus, overall, 103.3 million US adults now have hypertension, compared with 72.2 million under the JNC 7 criteria.

In addition, the new guidelines expanded the population of adults for whom antihypertensive drug treatment is recommended to 36.2% (81.9 million). However, this represents only a 1.9% absolute increase over the JNC 7 recommendations (34.3%) and a 5.1% absolute increase over the JNC 8 recommendations.¹⁴

SPRINT: INTENSIVE TREATMENT IS BENEFICIAL

The new ACC/AHA guidelines¹ were based on evidence from several trials, including the Systolic Blood Pressure Intervention Trial (SPRINT).¹⁵

This multicenter trial investigated the effect of intensive blood pressure treatment on cardiovascular disease risk.¹⁶ The primary outcome was a composite of myocardial infarction, acute coronary syndrome, stroke, and heart failure.

The trial enrolled 9,361 participants at least 50 years of age with systolic blood pressure 130 mm Hg or higher and at least 1 additional risk factor for cardiovascular disease. It excluded anyone with a history of diabetes mellitus, stroke, symptomatic heart failure, or end-stage renal disease.

Two interventions were compared: 

• Intensive treatment, with a systolic blood pressure goal of less than 120 mm Hg: the protocol called for polytherapy, even for participants who were 75 or older if their blood pressure was 140 mm Hg or higher
• Standard treatment, with a systolic blood pressure goal of less than 140 mm Hg: it used polytherapy for patients whose systolic blood pressure was 160 mm Hg or higher.

The trial was intended to last 5 years but was stopped early at a median of 3.26 years owing to a significantly lower rate of the primary composite outcome in the intensive-treatment group: 1.65% per year vs 2.19%, a 25% relative risk reduction (P < .001) or a 0.54% absolute risk reduction. We calculate the number needed to treat (NNT) for 1 year to prevent 1 event as 185, and over the 3.26 years of the trial, the investigators calculated the NNT as 61. Similarly, the rate of death from any cause was also lower with intensive treatment, 1.03% per year vs 1.40% per year, a 27% relative risk reduction (P = .003) or a 0.37% absolute risk reduction, NNT 270.

Using these findings, Bress et al¹⁶ estimated that implementing intensive blood pressure goals could prevent 107,500 deaths annually.

The downside is adverse effects. In SPRINT,¹⁵ the intensive-treatment group experienced significantly higher rates of serious adverse effects than the standard-treatment group, ie:

• Hypotension 2.4% vs 1.4%, P = .001
• Syncope 2.3% vs 1.7%, P = .05
• Electrolyte abnormalities 3.1% vs 2.3%, P = .02)
• Acute kidney injury or kidney failure 4.1% vs 2.5%, P < .001
• Any treatment-related adverse event 4.7% vs 2.5%, P = .001.

Thus, Bress et al¹⁶ estimated that fully implementing the intensive-treatment goals could cause an additional 56,100 episodes of hypotension per year, 34,400 cases of syncope, 43,400 serious electrolyte disorders, and 88,700 cases of acute kidney injury. All told, about 3 million Americans could suffer a serious adverse effect under the intensive-treatment goals.

 

 

SPRINT caveats and limitations

SPRINT¹⁵ was stopped early, after 3.26 years instead of the planned 5 years. The true risk-benefit ratio may have been different if the trial had been extended longer.

In addition, SPRINT used automated office blood pressure measurements in which patients were seated alone and a device (Model 907, Omron Healthcare) took 3 blood pressure measurements at 1-minute intervals after 5 minutes of quiet rest. This was designed to reduce elevated blood pressure readings in the presence of a healthcare professional in a medical setting (ie, “white coat” hypertension).

Many physicians are still taking blood pressure manually, which tends to give higher readings. Therefore, if they aim for a lower goal, they may risk overtreating the patient.

About 50% of patients did not achieve the target systolic blood pressure (< 120 mm Hg) despite receiving an average of 2.8 antihypertensive medications in the intensive-treatment group and 1.8 in the standard-treatment group. The use of antihypertensive medications, however, was not a controlled variable in the trial, and practitioners chose the appropriate drugs for their patients.

Diastolic pressure, which can be markedly lower in older hypertensive patients, was largely ignored, although lower diastolic pressure may have contributed to higher syncope rates in response to alpha blockers and calcium blockers.

Moreover, the trial excluded those with significant comorbidities and those younger than 50 (the mean age was 67.9), which limits the generalizability of the results.

JNC 8 VS SPRINT GOALS: WHAT'S THE EFFECT ON OUTCOMES?

JNC 8⁴ recommended a relaxed target of less than 140/90 mm Hg for adults younger than 60, including those with chronic kidney disease or diabetes, and less than 150/90 mm Hg for adults 60 and older. The SPRINT findings upended those recommendations, showing that intensive treatment in adults age 75 or older significantly improved the composite cardiovascular disease outcome (2.59 vs 3.85 events per year; P < .001) and all-cause mortality (1.78 vs 2.63 events per year; P < .05) compared with standard treatment.¹⁷ Also, a subset review of SPRINT trial data found no difference in benefit based on chronic kidney disease status.¹⁸

A meta-analysis of 74 clinical trials (N = 306,273) offers a compromise between the SPRINT findings and the JNC 8 recommendations.¹⁹ It found that the beneficial effect of blood pressure treatment depended on the patient’s baseline systolic blood pressure. In those with a baseline systolic pressure of 160 mm Hg or higher, treatment reduced cardiovascular mortality by about 15% (relative risk [RR] 0.85; 95% confidence interval [CI] 0.77–0.95). In patients with systolic pressure below 140 mm Hg, treatment effects were neutral (RR 1.03, 95% CI 0.87–1.20) and not associated with any benefit as primary prevention, although data suggest it may reduce the risk of adverse outcomes in patients with coronary heart disease.

OTHER TRIALS THAT INFLUENCED THE GUIDELINES

SPRINT was important for refining the appropriate targets for blood pressure treatment, but several other trials also influenced the ACC/AHA guidelines (Table 3).^20–24

SHEP and HYVET (the Systolic Hypertension in the Elderly Program²⁰ and the Hypertension in the Very Elderly Trial)²¹ supported intensive blood pressure treatment for older patients by reporting a reduction in fatal and nonfatal stroke risks for those with a systolic blood pressure above 160 mm Hg.

FEVER (the Felodipine Event Reduction study)²² found that treatment with a calcium channel blocker in even a low dose can significantly decrease cardiovascular events, cardiovascular disease, and heart failure compared with no treatment.

JATOS and VALISH (the Japanese Trial to Assess Optimal Systolic Blood Pressure in Elderly Hypertensive Patients²³ and the Valsartan in Elderly Isolated Systolic Hypertension study)²⁴ found that outcomes were similar with intensive vs standard treatment.

Ettehad et al²⁵ performed a meta-analysis of 123 studies with more than 600,000 participants that provided strong evidence supporting blood pressure treatment goals below 130/90 mm Hg, in line with the SPRINT trial results.

BLOOD PRESSURE ISN’T EVERYTHING

Other trials remind us that although blood pressure is important, it is not the only factor affecting cardiovascular risk.

HOPE (the Heart Outcomes Prevention Evaluation)²⁶ investigated the use of ramipril (an ACE inhibitor) in preventing myocardial infarction, stroke, or cardiovascular death in patients at high risk of cardiovascular events. The study included 9,297 participants over age 55 (mean age 66) with a baseline blood pressure 139/79 mm Hg. Follow-up was 4.5 years.

Ramipril was better than placebo, with significantly fewer patients experiencing adverse end points in the ramipril group compared with the placebo group:

• Myocardial infarction 9.9% vs 12.3%, RR 0.80, P < .001
• Cardiovascular death 6.1% vs 8.1%, RR  0.74, P < .001
• Stroke 3.4% vs 4.9%, RR = .68, P < .001
• The composite end point 14.0% vs 17.8%, RR 0.78, P < .001).

Results were even better in the subset of patients who had diabetes.²⁷ However, the decrease in blood pressure attributable to anti­hypertensive therapy with ramipril was minimal (3–4 mm Hg systolic and 1–2 mm Hg diastolic). This slight change should not have been enough to produce significant differences in clinical outcomes, a major limitation of this trial. The investigators speculated that the positive results may be due to a class effect of ACE inhibitors.²⁶

HOPE 3^28–30 explored the effect of blood pressure- and cholesterol-controlling drugs on the same primary end points but in patients at intermediate risk of major cardiovascular events. Investigators randomized the 12,705 patients to 4 treatment groups:

• Blood pressure control with candesartan (an ARB) plus hydrochlorothiazide (a thiazide diuretic)
• Cholesterol control with rosuvastatin (a statin)
• Blood pressure plus cholesterol control
• Placebo.

Therapy was started at a systolic blood pressure above 140 mm Hg.

Compared with placebo, the rate of composite events was significantly reduced in the rosuvastatin group (3.7% vs 4.8%, HR 0.76, P = .002)²⁸ and the candesartan-hydrochlorothiazide-rosuvastatin group (3.6% vs 5.0%, HR 0.71; P = .005)²⁹ but not in the candesartan-hydrochlorothiazide group (4.1% vs 4.4%; HR 0.93; P = .40).³⁰

In addition, a subgroup analysis comparing active treatment vs placebo found a significant reduction in major cardiovascular events for treated patients whose baseline systolic blood pressure was in the upper third (> 143.5 mm Hg, mean 154.1 mm Hg), while treated patients in the lower middle and lower thirds had no significant reduction.³⁰

These results suggest that intensive treatment to achieve a systolic blood pressure below 140 mm Hg in patients at intermediate risk may not be helpful. Nevertheless, there seems to be agreement that intensive treatment generally leads to a reduction in cardiovascular events. The results also show the benefit of lowering cholesterol.

Bundy et al³¹ performed a meta-analysis that provides support for intensive antihypertensive treatment. Reviewing 42 clinical trials in more than 144,000 patients, they found that treating to reach a target systolic blood pressure of 120 to 124 mm Hg can reduce cardiovascular events and all-cause mortality.

The trade-off is a minimal increase in the risk of adverse events. Also, the risk-benefit ratio of intensive treatment seems to vary in different patient subgroups.

 

WHAT ABOUT PATIENTS WITH COMORBIDITIES?

The debate over intensive vs standard treatment in blood pressure management extends beyond hypertension and includes important comorbidities such as diabetes, stroke, and renal disease. Patients with a history of stroke or end-stage renal disease have only a minimal mention in the AHA/ACC guidelines.

Diabetes

Emdin et al,³² in a meta-analysis of 40 trials that included more than 100,000 patients with diabetes, concluded that a 10-mm Hg lowering of systolic blood pressure significantly reduces the rates of all-cause mortality, cardiovascular disease, coronary heart disease, stroke, albuminuria, and retinopathy. Stratifying the results according to the systolic blood pressure achieved (≥ 130 or < 130 mm Hg), the relative risks of mortality, coronary heart disease, cardiovascular disease, heart failure, and albuminuria were actually lower in the higher stratum than in the lower.

ACCORD (the Action to Control Cardiovascular Risk in Diabetes)³³ study provides contrary results. It examined intensive and standard blood pressure control targets in patients with type 2 diabetes at high risk of cardiovascular events, using primary outcome measures similar to those in SPRINT. It found no significant difference in fatal and nonfatal cardiovascular events between the intensive and standard blood pressure target arms.

Despite those results, the ACC/AHA guidelines still advocate for more intensive treatment (goal < 130/80 mm Hg) in all patients, including those with diabetes.¹

The ADA position statement (September 2017) recommended a target below 140/90 mm Hg in patients with diabetes and hypertension.⁸ However, they also noted that lower systolic and diastolic blood pressure targets, such as below 130/80 mm Hg, may be appropriate for patients at high risk of cardiovascular disease “if they can be achieved without undue treatment burden.”⁸ Thus, it is not clear which blood pressure targets in patients with diabetes are the best.

Stroke

In patients with stroke, AHA/ACC guidelines¹ recommend treatment if the blood pressure is 140/90 mm Hg or higher because antihypertensive therapy has been associated with a decrease in the recurrence of transient ischemic attack and stroke. The ideal target blood pressure is not known, but a goal of less than 130/80 mm Hg may be reasonable.

In the Secondary Prevention of Small Subcortical Strokes (SPS3) trial, a retrospective open-label trial, a target blood pressure below 130/80 mm Hg in patients with a history of lacunar stroke was associated with a lower risk of intracranial hemorrhage, but the difference was not statistically significant.³⁴ For this reason, the ACC/AHA guidelines consider it reasonable to aim for a systolic blood pressure below 130 mm Hg in these patients.¹

Renal disease

The ACC/AHA guidelines do not address how to manage hypertension in patients with end-stage renal disease, but for patients with chronic kidney disease they recommend a blood pressure target below 130/80 mm Hg.¹ This recommendation is derived from the SPRINT trial,¹⁵ in which patients with stage 3 or 4 chronic kidney disease accounted for 28% of the study population. In that subgroup, intensive blood pressure control seemed to provide the same benefits for reduction in cardiovascular death and all-cause mortality.

TREAT PATIENTS, NOT NUMBERS

Blood pressure targets should be applied in the appropriate clinical context and on a patient-by-patient basis. In clinical practice, one size does not always fit all, as special cases exist.

For example, blood pressure can oscillate widely in patients with autonomic nerve disorders, making it difficult to strive for a specific target, especially an intensive one. Thus, it may be necessary to allow higher systolic blood pressure in these patients. Similarly, patients with diabetes or chronic kidney disease may be at higher risk of kidney injury with more intensive blood pressure management.

Treating numbers rather than patients may result in unbalanced patient care. The optimal approach to blood pressure management relies on a comprehensive risk factor assessment and shared decision-making with the patient before setting specific blood pressure targets.

OUR APPROACH

We aim for a blood pressure goal below 130/80 mm Hg for all patients with cardiovascular disease, according to the AHA/ACC guidelines. We aim for that same target in patients without cardiovascular disease but who have an elevated estimated cardiovascular risk (> 10%) over the next 10 years.

We recognize, however, that the benefits of aggressive blood pressure reduction may not be as clear in all patients, such as those with diabetes. We also recognize that some patient subgroups are at high risk of adverse events, including those with low diastolic pressure, chronic kidney disease, a history of falls, and older age. In those patients, we are extremely judicious when titrating antihypertensive medications. We often make smaller titrations, at longer intervals, and with more frequent laboratory testing and in-office follow-up.

Our process of managing hypertension through intensive blood pressure control to achieve lower systolic blood pressure targets requires a concerted effort among healthcare providers at all levels. It especially requires more involvement and investment from primary care providers to individualize treatment in their patients. This process has helped us to reach our treatment goals while limiting adverse effects of lower blood pressure targets.

MOVING FORWARD

Hypertension is a major risk factor for cardiovascular disease, and intensive blood pressure control has the potential to significantly reduce rates of morbidity and death associated with cardiovascular disease. Thus, a general consensus on the definition of hypertension and treatment goals is essential to reduce the risk of cardiovascular events in this large patient population.

Intensive blood pressure treatment has shown efficacy, but it has a small accompanying risk of adverse events, which varies in patient subgroups and affects the benefit-risk ratio of this therapy. For example, the cardiovascular benefit of intensive treatment is less clear in diabetic patients, and the risk of adverse events may be higher in older patients with chronic kidney disease.

Moving forward, more research is needed into the effects of intensive and standard treatment on patients of all ages, those with common comorbid conditions, and those with other important factors such as diastolic hypertension.

Finally, the various medical societies should collaborate on hypertension guideline development. This would require considerable planning and coordination but would ultimately be useful in creating a generalizable approach to hypertension management.

When treating high blood pressure, how low should we try to go? Debate continues about optimal blood pressure goals after publication of guidelines from the American College of Cardiology and American Heart Association (ACC/AHA) in 2017 that set or permitted a treatment goal of less than 130 mm Hg, depending on the population.¹

In this article, we summarize the evolution of hypertension guidelines and the evidence behind them.

HOW THE GOALS EVOLVED

JNC 7, 2003: 140/90 or 130/80

The seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7),² published in 2003, specified treatment goals of:

• < 140/90 mm Hg for most patients
• < 130/80 mm Hg for those with diabetes or chronic kidney disease.

JNC 7 defined hypertension as 140/90 mm Hg or higher, and introduced the classification of prehypertension for patients with a systolic blood pressure of 120 to 139 mm Hg or a diastolic blood pressure of 80 to 89 mm Hg. It advocated managing systolic hypertension in patients over age 50. It also recommended lifestyle changes such as the Dietary Approaches to Stop Hypertension (DASH) diet, moderate alcohol consumption, weight loss, and a physical activity plan.

JNC 7 provided much-needed clarity and uniformity to managing hypertension. Since then, various scientific groups have published their own guidelines (Table 1).^1–9

ACC/AHA/CDC 2014: 140/90

In 2014, the ACC, AHA, and US Centers for Disease Control and Prevention (CDC) published an evidence-based algorithm for hypertension management.³ As in JNC 7, they suggested a blood pressure goal of less than 140/90 mm Hg, lifestyle modification, and polytherapy, eg, a thiazide diuretic for stage 1 hypertension (< 160/100 mm Hg) and combination therapy with a thiazide diuretic and an angiotensin-converting enzyme (ACE) inhibitor, angiotensin II receptor blocker (ARB), or calcium channel blocker for stage 2 hypertension (≥ 160/100 mm Hg).

JNC 8 2014: 140/90 or 150/90

Soon after, the much-anticipated report of the panel members appointed to the eighth JNC (JNC 8) was published.⁴ Previous JNC reports were written and published under the auspices of the National Heart, Lung, and Blood Institute, but while the JNC 8 report was being prepared, this government body announced it would no longer publish guidelines.

In contrast to JNC 7, the JNC 8 panel based its recommendations on a systematic review of randomized clinical trials. However, the process and methodology were controversial, especially as the panel excluded some important clinical trials from the analysis.

JNC 8 relaxed the targets in several subgroups, such as patients over age 60 and those with diabetes and chronic kidney disease, due to a lack of definitive evidence on the impact of blood pressure targets lower than 140/90 mm Hg in these groups. Thus, their goals were:

• < 140/90 mm Hg for patients under age 60
• < 150/90 mm Hg for patients age 60 and older.

Table 2 shows the differences in recommendations between JNC 7 and JNC 8.

Of note, a minority of the JNC 8 panel disagreed with the new targets and provided evidence for keeping the systolic blood pressure target below 140 mm Hg for patients 60 and older.⁵ Further, the JNC 8 report was not endorsed by several important societies, ie, the AHA, ACC, National Heart, Lung, and Blood Institute, and American Society of Hypertension (ASH). These issues compromised the acceptance and applicability of the guidelines.

ASH/ISH 2014: 140/90 or 150/90

Also in 2014, the ASH and the International Society of Hypertension released their own report.⁶ Their goals:

• < 140/90 mm Hg for most patients
• < 150/90 mm Hg for patients age 80 and older.

AHA/ACC/ASH 2015: Goals in subgroups

In 2015, the AHA, ACC, and ASH released a joint scientific statement outlining hypertension goals for specific patient populations⁷:

• < 150/90 mm Hg for those age 80 and older
• < 140/90 mm Hg for those with coronary artery disease
• < 130/80 mm Hg for those with comorbidities such as diabetes and cardiovascular disease.

ADA 2016: Goals for patients with diabetes

In 2016, the American Diabetes Association (ADA) set the following blood pressure goals for patients with diabetes⁸:

• < 140/90 mm Hg for adults with diabetes
• < 130/80 mm Hg for younger adults with diabetes and adults with a high risk of cardiovascular disease
• 120–160/80–105 mm Hg for pregnant patients with diabetes and preexisting hypertension who are treated with antihypertensive therapy.

 

 

ACP/AAFP 2017: Systolic 150 or 130

In 2017, the American College of Physicians (ACP) and the American Academy of Family Physicians (AAFP) recommended a relaxed systolic blood pressure target, ie, below 150 mm Hg, for adults over age 60, but a tighter goal of less than 140 mm Hg for the same age group if they have transient ischemic attack, stroke, or high cardiovascular risk.⁹

ACC/AHA 2017: 130/80

The 2017 ACC/AHA guidelines recommended a more aggressive goal of below 130/80 for all, including patients age 65 and older.¹

This is a class I (strong) recommendation for patients with known cardiovascular disease or a 10-year risk of a cardiovascular event of 10% or higher, with a B-R level of evidence for the systolic goal (ie, moderate-quality, based on systematic review of randomized controlled trials) and a C-EO level of evidence for the diastolic goal (ie, based on expert opinion).

For patients who do not have cardiovascular disease and who are at lower risk of it, this is a class IIb (weak) recommendation, ie, it “may be reasonable,” with a B-NR level of evidence (moderate-quality, based on nonrandomized studies) for the systolic goal and C-EO (expert opinion) for the diastolic goal.

For many patients, this involves drug treatment. For those with known cardiovascular disease or a 10-year risk of an atherosclerotic cardiovascular disease event of 10% or higher, the ACC/AHA guidelines say that drug treatment “is recommended” if their average blood pressure is 130/80 mm Hg or higher (class I recommendation, based on strong evidence for the systolic threshold and expert option for the diastolic). For those without cardiovascular disease and at lower risk, drug treatment is recommended if their average blood pressure is 140/90 mm Hg or higher (also class I, but based on limited data).

EVERYONE AGREES ON LIFESTYLE

Although the guidelines differ in their blood pressure targets, they consistently recommend lifestyle modifications.

Lifestyle modifications, first described in JNC 7, included weight loss, sodium restriction, and the DASH diet, which is rich in fruits, vegetables, low-fat dairy products, whole grains, poultry, and fish, and low in red meat, sweets, cholesterol, and total and saturated fat.²

These recommendations were based on results from 3 large randomized controlled trials in patients with and without hypertension.^10–12 In patients with no history of hypertension, interventions to promote weight loss and sodium restriction significantly reduced blood pressure and the incidence of hypertension (the latter by as much as 77%) compared with usual care.^10,11

In patients with and without hypertension, lowering sodium intake in conjunction with the DASH diet was associated with substantially larger reductions in systolic blood pressure.¹²

The recommendation to lower sodium intake has not changed in the guideline revisions. Meanwhile, other modifications have been added, such as incorporating both aerobic and resistance exercise and moderating alcohol intake. These recommendations have a class I level of evidence (ie, strongest level) in the 2017 ACC/AHA guidelines.¹

HYPERTENSION BEGINS AT 130/80

The definition of hypertension changed in the 2017 ACC/AHA guidelines¹: previously set at 140/90 mm Hg or higher, it is now 130/80 mm Hg or higher for all age groups. Adults with systolic blood pressure of 130 to 139 mm Hg or diastolic blood pressure of 80 to 89 mm Hg are now classified as having stage 1 hypertension.

Under the new definition, the number of US adults who have hypertension expanded to 45.6% of the general population,¹³ up from 31.9% under the JNC 7 definition. Thus, overall, 103.3 million US adults now have hypertension, compared with 72.2 million under the JNC 7 criteria.

In addition, the new guidelines expanded the population of adults for whom antihypertensive drug treatment is recommended to 36.2% (81.9 million). However, this represents only a 1.9% absolute increase over the JNC 7 recommendations (34.3%) and a 5.1% absolute increase over the JNC 8 recommendations.¹⁴

SPRINT: INTENSIVE TREATMENT IS BENEFICIAL

The new ACC/AHA guidelines¹ were based on evidence from several trials, including the Systolic Blood Pressure Intervention Trial (SPRINT).¹⁵

This multicenter trial investigated the effect of intensive blood pressure treatment on cardiovascular disease risk.¹⁶ The primary outcome was a composite of myocardial infarction, acute coronary syndrome, stroke, and heart failure.

The trial enrolled 9,361 participants at least 50 years of age with systolic blood pressure 130 mm Hg or higher and at least 1 additional risk factor for cardiovascular disease. It excluded anyone with a history of diabetes mellitus, stroke, symptomatic heart failure, or end-stage renal disease.

Two interventions were compared: 

• Intensive treatment, with a systolic blood pressure goal of less than 120 mm Hg: the protocol called for polytherapy, even for participants who were 75 or older if their blood pressure was 140 mm Hg or higher
• Standard treatment, with a systolic blood pressure goal of less than 140 mm Hg: it used polytherapy for patients whose systolic blood pressure was 160 mm Hg or higher.

The trial was intended to last 5 years but was stopped early at a median of 3.26 years owing to a significantly lower rate of the primary composite outcome in the intensive-treatment group: 1.65% per year vs 2.19%, a 25% relative risk reduction (P < .001) or a 0.54% absolute risk reduction. We calculate the number needed to treat (NNT) for 1 year to prevent 1 event as 185, and over the 3.26 years of the trial, the investigators calculated the NNT as 61. Similarly, the rate of death from any cause was also lower with intensive treatment, 1.03% per year vs 1.40% per year, a 27% relative risk reduction (P = .003) or a 0.37% absolute risk reduction, NNT 270.

Using these findings, Bress et al¹⁶ estimated that implementing intensive blood pressure goals could prevent 107,500 deaths annually.

The downside is adverse effects. In SPRINT,¹⁵ the intensive-treatment group experienced significantly higher rates of serious adverse effects than the standard-treatment group, ie:

• Hypotension 2.4% vs 1.4%, P = .001
• Syncope 2.3% vs 1.7%, P = .05
• Electrolyte abnormalities 3.1% vs 2.3%, P = .02)
• Acute kidney injury or kidney failure 4.1% vs 2.5%, P < .001
• Any treatment-related adverse event 4.7% vs 2.5%, P = .001.

Thus, Bress et al¹⁶ estimated that fully implementing the intensive-treatment goals could cause an additional 56,100 episodes of hypotension per year, 34,400 cases of syncope, 43,400 serious electrolyte disorders, and 88,700 cases of acute kidney injury. All told, about 3 million Americans could suffer a serious adverse effect under the intensive-treatment goals.

 

 

SPRINT caveats and limitations

SPRINT¹⁵ was stopped early, after 3.26 years instead of the planned 5 years. The true risk-benefit ratio may have been different if the trial had been extended longer.

In addition, SPRINT used automated office blood pressure measurements in which patients were seated alone and a device (Model 907, Omron Healthcare) took 3 blood pressure measurements at 1-minute intervals after 5 minutes of quiet rest. This was designed to reduce elevated blood pressure readings in the presence of a healthcare professional in a medical setting (ie, “white coat” hypertension).

Many physicians are still taking blood pressure manually, which tends to give higher readings. Therefore, if they aim for a lower goal, they may risk overtreating the patient.

About 50% of patients did not achieve the target systolic blood pressure (< 120 mm Hg) despite receiving an average of 2.8 antihypertensive medications in the intensive-treatment group and 1.8 in the standard-treatment group. The use of antihypertensive medications, however, was not a controlled variable in the trial, and practitioners chose the appropriate drugs for their patients.

Diastolic pressure, which can be markedly lower in older hypertensive patients, was largely ignored, although lower diastolic pressure may have contributed to higher syncope rates in response to alpha blockers and calcium blockers.

Moreover, the trial excluded those with significant comorbidities and those younger than 50 (the mean age was 67.9), which limits the generalizability of the results.

JNC 8 VS SPRINT GOALS: WHAT'S THE EFFECT ON OUTCOMES?

JNC 8⁴ recommended a relaxed target of less than 140/90 mm Hg for adults younger than 60, including those with chronic kidney disease or diabetes, and less than 150/90 mm Hg for adults 60 and older. The SPRINT findings upended those recommendations, showing that intensive treatment in adults age 75 or older significantly improved the composite cardiovascular disease outcome (2.59 vs 3.85 events per year; P < .001) and all-cause mortality (1.78 vs 2.63 events per year; P < .05) compared with standard treatment.¹⁷ Also, a subset review of SPRINT trial data found no difference in benefit based on chronic kidney disease status.¹⁸

A meta-analysis of 74 clinical trials (N = 306,273) offers a compromise between the SPRINT findings and the JNC 8 recommendations.¹⁹ It found that the beneficial effect of blood pressure treatment depended on the patient’s baseline systolic blood pressure. In those with a baseline systolic pressure of 160 mm Hg or higher, treatment reduced cardiovascular mortality by about 15% (relative risk [RR] 0.85; 95% confidence interval [CI] 0.77–0.95). In patients with systolic pressure below 140 mm Hg, treatment effects were neutral (RR 1.03, 95% CI 0.87–1.20) and not associated with any benefit as primary prevention, although data suggest it may reduce the risk of adverse outcomes in patients with coronary heart disease.

OTHER TRIALS THAT INFLUENCED THE GUIDELINES

SPRINT was important for refining the appropriate targets for blood pressure treatment, but several other trials also influenced the ACC/AHA guidelines (Table 3).^20–24

SHEP and HYVET (the Systolic Hypertension in the Elderly Program²⁰ and the Hypertension in the Very Elderly Trial)²¹ supported intensive blood pressure treatment for older patients by reporting a reduction in fatal and nonfatal stroke risks for those with a systolic blood pressure above 160 mm Hg.

FEVER (the Felodipine Event Reduction study)²² found that treatment with a calcium channel blocker in even a low dose can significantly decrease cardiovascular events, cardiovascular disease, and heart failure compared with no treatment.

JATOS and VALISH (the Japanese Trial to Assess Optimal Systolic Blood Pressure in Elderly Hypertensive Patients²³ and the Valsartan in Elderly Isolated Systolic Hypertension study)²⁴ found that outcomes were similar with intensive vs standard treatment.

Ettehad et al²⁵ performed a meta-analysis of 123 studies with more than 600,000 participants that provided strong evidence supporting blood pressure treatment goals below 130/90 mm Hg, in line with the SPRINT trial results.

BLOOD PRESSURE ISN’T EVERYTHING

Other trials remind us that although blood pressure is important, it is not the only factor affecting cardiovascular risk.

HOPE (the Heart Outcomes Prevention Evaluation)²⁶ investigated the use of ramipril (an ACE inhibitor) in preventing myocardial infarction, stroke, or cardiovascular death in patients at high risk of cardiovascular events. The study included 9,297 participants over age 55 (mean age 66) with a baseline blood pressure 139/79 mm Hg. Follow-up was 4.5 years.

Ramipril was better than placebo, with significantly fewer patients experiencing adverse end points in the ramipril group compared with the placebo group:

• Myocardial infarction 9.9% vs 12.3%, RR 0.80, P < .001
• Cardiovascular death 6.1% vs 8.1%, RR  0.74, P < .001
• Stroke 3.4% vs 4.9%, RR = .68, P < .001
• The composite end point 14.0% vs 17.8%, RR 0.78, P < .001).

Results were even better in the subset of patients who had diabetes.²⁷ However, the decrease in blood pressure attributable to anti­hypertensive therapy with ramipril was minimal (3–4 mm Hg systolic and 1–2 mm Hg diastolic). This slight change should not have been enough to produce significant differences in clinical outcomes, a major limitation of this trial. The investigators speculated that the positive results may be due to a class effect of ACE inhibitors.²⁶

HOPE 3^28–30 explored the effect of blood pressure- and cholesterol-controlling drugs on the same primary end points but in patients at intermediate risk of major cardiovascular events. Investigators randomized the 12,705 patients to 4 treatment groups:

• Blood pressure control with candesartan (an ARB) plus hydrochlorothiazide (a thiazide diuretic)
• Cholesterol control with rosuvastatin (a statin)
• Blood pressure plus cholesterol control
• Placebo.

Therapy was started at a systolic blood pressure above 140 mm Hg.

Compared with placebo, the rate of composite events was significantly reduced in the rosuvastatin group (3.7% vs 4.8%, HR 0.76, P = .002)²⁸ and the candesartan-hydrochlorothiazide-rosuvastatin group (3.6% vs 5.0%, HR 0.71; P = .005)²⁹ but not in the candesartan-hydrochlorothiazide group (4.1% vs 4.4%; HR 0.93; P = .40).³⁰

In addition, a subgroup analysis comparing active treatment vs placebo found a significant reduction in major cardiovascular events for treated patients whose baseline systolic blood pressure was in the upper third (> 143.5 mm Hg, mean 154.1 mm Hg), while treated patients in the lower middle and lower thirds had no significant reduction.³⁰

These results suggest that intensive treatment to achieve a systolic blood pressure below 140 mm Hg in patients at intermediate risk may not be helpful. Nevertheless, there seems to be agreement that intensive treatment generally leads to a reduction in cardiovascular events. The results also show the benefit of lowering cholesterol.

Bundy et al³¹ performed a meta-analysis that provides support for intensive antihypertensive treatment. Reviewing 42 clinical trials in more than 144,000 patients, they found that treating to reach a target systolic blood pressure of 120 to 124 mm Hg can reduce cardiovascular events and all-cause mortality.

The trade-off is a minimal increase in the risk of adverse events. Also, the risk-benefit ratio of intensive treatment seems to vary in different patient subgroups.

 

WHAT ABOUT PATIENTS WITH COMORBIDITIES?

The debate over intensive vs standard treatment in blood pressure management extends beyond hypertension and includes important comorbidities such as diabetes, stroke, and renal disease. Patients with a history of stroke or end-stage renal disease have only a minimal mention in the AHA/ACC guidelines.

Diabetes

Emdin et al,³² in a meta-analysis of 40 trials that included more than 100,000 patients with diabetes, concluded that a 10-mm Hg lowering of systolic blood pressure significantly reduces the rates of all-cause mortality, cardiovascular disease, coronary heart disease, stroke, albuminuria, and retinopathy. Stratifying the results according to the systolic blood pressure achieved (≥ 130 or < 130 mm Hg), the relative risks of mortality, coronary heart disease, cardiovascular disease, heart failure, and albuminuria were actually lower in the higher stratum than in the lower.

ACCORD (the Action to Control Cardiovascular Risk in Diabetes)³³ study provides contrary results. It examined intensive and standard blood pressure control targets in patients with type 2 diabetes at high risk of cardiovascular events, using primary outcome measures similar to those in SPRINT. It found no significant difference in fatal and nonfatal cardiovascular events between the intensive and standard blood pressure target arms.

Despite those results, the ACC/AHA guidelines still advocate for more intensive treatment (goal < 130/80 mm Hg) in all patients, including those with diabetes.¹

The ADA position statement (September 2017) recommended a target below 140/90 mm Hg in patients with diabetes and hypertension.⁸ However, they also noted that lower systolic and diastolic blood pressure targets, such as below 130/80 mm Hg, may be appropriate for patients at high risk of cardiovascular disease “if they can be achieved without undue treatment burden.”⁸ Thus, it is not clear which blood pressure targets in patients with diabetes are the best.

Stroke

In patients with stroke, AHA/ACC guidelines¹ recommend treatment if the blood pressure is 140/90 mm Hg or higher because antihypertensive therapy has been associated with a decrease in the recurrence of transient ischemic attack and stroke. The ideal target blood pressure is not known, but a goal of less than 130/80 mm Hg may be reasonable.

In the Secondary Prevention of Small Subcortical Strokes (SPS3) trial, a retrospective open-label trial, a target blood pressure below 130/80 mm Hg in patients with a history of lacunar stroke was associated with a lower risk of intracranial hemorrhage, but the difference was not statistically significant.³⁴ For this reason, the ACC/AHA guidelines consider it reasonable to aim for a systolic blood pressure below 130 mm Hg in these patients.¹

Renal disease

The ACC/AHA guidelines do not address how to manage hypertension in patients with end-stage renal disease, but for patients with chronic kidney disease they recommend a blood pressure target below 130/80 mm Hg.¹ This recommendation is derived from the SPRINT trial,¹⁵ in which patients with stage 3 or 4 chronic kidney disease accounted for 28% of the study population. In that subgroup, intensive blood pressure control seemed to provide the same benefits for reduction in cardiovascular death and all-cause mortality.

TREAT PATIENTS, NOT NUMBERS

Blood pressure targets should be applied in the appropriate clinical context and on a patient-by-patient basis. In clinical practice, one size does not always fit all, as special cases exist.

For example, blood pressure can oscillate widely in patients with autonomic nerve disorders, making it difficult to strive for a specific target, especially an intensive one. Thus, it may be necessary to allow higher systolic blood pressure in these patients. Similarly, patients with diabetes or chronic kidney disease may be at higher risk of kidney injury with more intensive blood pressure management.

Treating numbers rather than patients may result in unbalanced patient care. The optimal approach to blood pressure management relies on a comprehensive risk factor assessment and shared decision-making with the patient before setting specific blood pressure targets.

OUR APPROACH

We aim for a blood pressure goal below 130/80 mm Hg for all patients with cardiovascular disease, according to the AHA/ACC guidelines. We aim for that same target in patients without cardiovascular disease but who have an elevated estimated cardiovascular risk (> 10%) over the next 10 years.

We recognize, however, that the benefits of aggressive blood pressure reduction may not be as clear in all patients, such as those with diabetes. We also recognize that some patient subgroups are at high risk of adverse events, including those with low diastolic pressure, chronic kidney disease, a history of falls, and older age. In those patients, we are extremely judicious when titrating antihypertensive medications. We often make smaller titrations, at longer intervals, and with more frequent laboratory testing and in-office follow-up.

Our process of managing hypertension through intensive blood pressure control to achieve lower systolic blood pressure targets requires a concerted effort among healthcare providers at all levels. It especially requires more involvement and investment from primary care providers to individualize treatment in their patients. This process has helped us to reach our treatment goals while limiting adverse effects of lower blood pressure targets.

MOVING FORWARD

Hypertension is a major risk factor for cardiovascular disease, and intensive blood pressure control has the potential to significantly reduce rates of morbidity and death associated with cardiovascular disease. Thus, a general consensus on the definition of hypertension and treatment goals is essential to reduce the risk of cardiovascular events in this large patient population.

Intensive blood pressure treatment has shown efficacy, but it has a small accompanying risk of adverse events, which varies in patient subgroups and affects the benefit-risk ratio of this therapy. For example, the cardiovascular benefit of intensive treatment is less clear in diabetic patients, and the risk of adverse events may be higher in older patients with chronic kidney disease.

Moving forward, more research is needed into the effects of intensive and standard treatment on patients of all ages, those with common comorbid conditions, and those with other important factors such as diastolic hypertension.

Finally, the various medical societies should collaborate on hypertension guideline development. This would require considerable planning and coordination but would ultimately be useful in creating a generalizable approach to hypertension management.

When treating high blood pressure, how low should we try to go? Debate continues about optimal blood pressure goals after publication of guidelines from the American College of Cardiology and American Heart Association (ACC/AHA) in 2017 that set or permitted a treatment goal of less than 130 mm Hg, depending on the population.¹

In this article, we summarize the evolution of hypertension guidelines and the evidence behind them.

HOW THE GOALS EVOLVED

JNC 7, 2003: 140/90 or 130/80

The seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7),² published in 2003, specified treatment goals of:

• < 140/90 mm Hg for most patients
• < 130/80 mm Hg for those with diabetes or chronic kidney disease.

JNC 7 defined hypertension as 140/90 mm Hg or higher, and introduced the classification of prehypertension for patients with a systolic blood pressure of 120 to 139 mm Hg or a diastolic blood pressure of 80 to 89 mm Hg. It advocated managing systolic hypertension in patients over age 50. It also recommended lifestyle changes such as the Dietary Approaches to Stop Hypertension (DASH) diet, moderate alcohol consumption, weight loss, and a physical activity plan.

JNC 7 provided much-needed clarity and uniformity to managing hypertension. Since then, various scientific groups have published their own guidelines (Table 1).^1–9

ACC/AHA/CDC 2014: 140/90

In 2014, the ACC, AHA, and US Centers for Disease Control and Prevention (CDC) published an evidence-based algorithm for hypertension management.³ As in JNC 7, they suggested a blood pressure goal of less than 140/90 mm Hg, lifestyle modification, and polytherapy, eg, a thiazide diuretic for stage 1 hypertension (< 160/100 mm Hg) and combination therapy with a thiazide diuretic and an angiotensin-converting enzyme (ACE) inhibitor, angiotensin II receptor blocker (ARB), or calcium channel blocker for stage 2 hypertension (≥ 160/100 mm Hg).

JNC 8 2014: 140/90 or 150/90

Soon after, the much-anticipated report of the panel members appointed to the eighth JNC (JNC 8) was published.⁴ Previous JNC reports were written and published under the auspices of the National Heart, Lung, and Blood Institute, but while the JNC 8 report was being prepared, this government body announced it would no longer publish guidelines.

In contrast to JNC 7, the JNC 8 panel based its recommendations on a systematic review of randomized clinical trials. However, the process and methodology were controversial, especially as the panel excluded some important clinical trials from the analysis.

JNC 8 relaxed the targets in several subgroups, such as patients over age 60 and those with diabetes and chronic kidney disease, due to a lack of definitive evidence on the impact of blood pressure targets lower than 140/90 mm Hg in these groups. Thus, their goals were:

• < 140/90 mm Hg for patients under age 60
• < 150/90 mm Hg for patients age 60 and older.

Table 2 shows the differences in recommendations between JNC 7 and JNC 8.

Of note, a minority of the JNC 8 panel disagreed with the new targets and provided evidence for keeping the systolic blood pressure target below 140 mm Hg for patients 60 and older.⁵ Further, the JNC 8 report was not endorsed by several important societies, ie, the AHA, ACC, National Heart, Lung, and Blood Institute, and American Society of Hypertension (ASH). These issues compromised the acceptance and applicability of the guidelines.

ASH/ISH 2014: 140/90 or 150/90

Also in 2014, the ASH and the International Society of Hypertension released their own report.⁶ Their goals:

• < 140/90 mm Hg for most patients
• < 150/90 mm Hg for patients age 80 and older.

AHA/ACC/ASH 2015: Goals in subgroups

In 2015, the AHA, ACC, and ASH released a joint scientific statement outlining hypertension goals for specific patient populations⁷:

• < 150/90 mm Hg for those age 80 and older
• < 140/90 mm Hg for those with coronary artery disease
• < 130/80 mm Hg for those with comorbidities such as diabetes and cardiovascular disease.

ADA 2016: Goals for patients with diabetes

In 2016, the American Diabetes Association (ADA) set the following blood pressure goals for patients with diabetes⁸:

• < 140/90 mm Hg for adults with diabetes
• < 130/80 mm Hg for younger adults with diabetes and adults with a high risk of cardiovascular disease
• 120–160/80–105 mm Hg for pregnant patients with diabetes and preexisting hypertension who are treated with antihypertensive therapy.

 

 

ACP/AAFP 2017: Systolic 150 or 130

In 2017, the American College of Physicians (ACP) and the American Academy of Family Physicians (AAFP) recommended a relaxed systolic blood pressure target, ie, below 150 mm Hg, for adults over age 60, but a tighter goal of less than 140 mm Hg for the same age group if they have transient ischemic attack, stroke, or high cardiovascular risk.⁹

ACC/AHA 2017: 130/80

The 2017 ACC/AHA guidelines recommended a more aggressive goal of below 130/80 for all, including patients age 65 and older.¹

This is a class I (strong) recommendation for patients with known cardiovascular disease or a 10-year risk of a cardiovascular event of 10% or higher, with a B-R level of evidence for the systolic goal (ie, moderate-quality, based on systematic review of randomized controlled trials) and a C-EO level of evidence for the diastolic goal (ie, based on expert opinion).

For patients who do not have cardiovascular disease and who are at lower risk of it, this is a class IIb (weak) recommendation, ie, it “may be reasonable,” with a B-NR level of evidence (moderate-quality, based on nonrandomized studies) for the systolic goal and C-EO (expert opinion) for the diastolic goal.

For many patients, this involves drug treatment. For those with known cardiovascular disease or a 10-year risk of an atherosclerotic cardiovascular disease event of 10% or higher, the ACC/AHA guidelines say that drug treatment “is recommended” if their average blood pressure is 130/80 mm Hg or higher (class I recommendation, based on strong evidence for the systolic threshold and expert option for the diastolic). For those without cardiovascular disease and at lower risk, drug treatment is recommended if their average blood pressure is 140/90 mm Hg or higher (also class I, but based on limited data).

EVERYONE AGREES ON LIFESTYLE

Although the guidelines differ in their blood pressure targets, they consistently recommend lifestyle modifications.

Lifestyle modifications, first described in JNC 7, included weight loss, sodium restriction, and the DASH diet, which is rich in fruits, vegetables, low-fat dairy products, whole grains, poultry, and fish, and low in red meat, sweets, cholesterol, and total and saturated fat.²

These recommendations were based on results from 3 large randomized controlled trials in patients with and without hypertension.^10–12 In patients with no history of hypertension, interventions to promote weight loss and sodium restriction significantly reduced blood pressure and the incidence of hypertension (the latter by as much as 77%) compared with usual care.^10,11

In patients with and without hypertension, lowering sodium intake in conjunction with the DASH diet was associated with substantially larger reductions in systolic blood pressure.¹²

The recommendation to lower sodium intake has not changed in the guideline revisions. Meanwhile, other modifications have been added, such as incorporating both aerobic and resistance exercise and moderating alcohol intake. These recommendations have a class I level of evidence (ie, strongest level) in the 2017 ACC/AHA guidelines.¹

HYPERTENSION BEGINS AT 130/80

The definition of hypertension changed in the 2017 ACC/AHA guidelines¹: previously set at 140/90 mm Hg or higher, it is now 130/80 mm Hg or higher for all age groups. Adults with systolic blood pressure of 130 to 139 mm Hg or diastolic blood pressure of 80 to 89 mm Hg are now classified as having stage 1 hypertension.

Under the new definition, the number of US adults who have hypertension expanded to 45.6% of the general population,¹³ up from 31.9% under the JNC 7 definition. Thus, overall, 103.3 million US adults now have hypertension, compared with 72.2 million under the JNC 7 criteria.

In addition, the new guidelines expanded the population of adults for whom antihypertensive drug treatment is recommended to 36.2% (81.9 million). However, this represents only a 1.9% absolute increase over the JNC 7 recommendations (34.3%) and a 5.1% absolute increase over the JNC 8 recommendations.¹⁴

SPRINT: INTENSIVE TREATMENT IS BENEFICIAL

The new ACC/AHA guidelines¹ were based on evidence from several trials, including the Systolic Blood Pressure Intervention Trial (SPRINT).¹⁵

This multicenter trial investigated the effect of intensive blood pressure treatment on cardiovascular disease risk.¹⁶ The primary outcome was a composite of myocardial infarction, acute coronary syndrome, stroke, and heart failure.

The trial enrolled 9,361 participants at least 50 years of age with systolic blood pressure 130 mm Hg or higher and at least 1 additional risk factor for cardiovascular disease. It excluded anyone with a history of diabetes mellitus, stroke, symptomatic heart failure, or end-stage renal disease.

Two interventions were compared: 

• Intensive treatment, with a systolic blood pressure goal of less than 120 mm Hg: the protocol called for polytherapy, even for participants who were 75 or older if their blood pressure was 140 mm Hg or higher
• Standard treatment, with a systolic blood pressure goal of less than 140 mm Hg: it used polytherapy for patients whose systolic blood pressure was 160 mm Hg or higher.

The trial was intended to last 5 years but was stopped early at a median of 3.26 years owing to a significantly lower rate of the primary composite outcome in the intensive-treatment group: 1.65% per year vs 2.19%, a 25% relative risk reduction (P < .001) or a 0.54% absolute risk reduction. We calculate the number needed to treat (NNT) for 1 year to prevent 1 event as 185, and over the 3.26 years of the trial, the investigators calculated the NNT as 61. Similarly, the rate of death from any cause was also lower with intensive treatment, 1.03% per year vs 1.40% per year, a 27% relative risk reduction (P = .003) or a 0.37% absolute risk reduction, NNT 270.

Using these findings, Bress et al¹⁶ estimated that implementing intensive blood pressure goals could prevent 107,500 deaths annually.

The downside is adverse effects. In SPRINT,¹⁵ the intensive-treatment group experienced significantly higher rates of serious adverse effects than the standard-treatment group, ie:

• Hypotension 2.4% vs 1.4%, P = .001
• Syncope 2.3% vs 1.7%, P = .05
• Electrolyte abnormalities 3.1% vs 2.3%, P = .02)
• Acute kidney injury or kidney failure 4.1% vs 2.5%, P < .001
• Any treatment-related adverse event 4.7% vs 2.5%, P = .001.

Thus, Bress et al¹⁶ estimated that fully implementing the intensive-treatment goals could cause an additional 56,100 episodes of hypotension per year, 34,400 cases of syncope, 43,400 serious electrolyte disorders, and 88,700 cases of acute kidney injury. All told, about 3 million Americans could suffer a serious adverse effect under the intensive-treatment goals.

 

 

SPRINT caveats and limitations

SPRINT¹⁵ was stopped early, after 3.26 years instead of the planned 5 years. The true risk-benefit ratio may have been different if the trial had been extended longer.

In addition, SPRINT used automated office blood pressure measurements in which patients were seated alone and a device (Model 907, Omron Healthcare) took 3 blood pressure measurements at 1-minute intervals after 5 minutes of quiet rest. This was designed to reduce elevated blood pressure readings in the presence of a healthcare professional in a medical setting (ie, “white coat” hypertension).

Many physicians are still taking blood pressure manually, which tends to give higher readings. Therefore, if they aim for a lower goal, they may risk overtreating the patient.

About 50% of patients did not achieve the target systolic blood pressure (< 120 mm Hg) despite receiving an average of 2.8 antihypertensive medications in the intensive-treatment group and 1.8 in the standard-treatment group. The use of antihypertensive medications, however, was not a controlled variable in the trial, and practitioners chose the appropriate drugs for their patients.

Diastolic pressure, which can be markedly lower in older hypertensive patients, was largely ignored, although lower diastolic pressure may have contributed to higher syncope rates in response to alpha blockers and calcium blockers.

Moreover, the trial excluded those with significant comorbidities and those younger than 50 (the mean age was 67.9), which limits the generalizability of the results.

JNC 8 VS SPRINT GOALS: WHAT'S THE EFFECT ON OUTCOMES?

JNC 8⁴ recommended a relaxed target of less than 140/90 mm Hg for adults younger than 60, including those with chronic kidney disease or diabetes, and less than 150/90 mm Hg for adults 60 and older. The SPRINT findings upended those recommendations, showing that intensive treatment in adults age 75 or older significantly improved the composite cardiovascular disease outcome (2.59 vs 3.85 events per year; P < .001) and all-cause mortality (1.78 vs 2.63 events per year; P < .05) compared with standard treatment.¹⁷ Also, a subset review of SPRINT trial data found no difference in benefit based on chronic kidney disease status.¹⁸

A meta-analysis of 74 clinical trials (N = 306,273) offers a compromise between the SPRINT findings and the JNC 8 recommendations.¹⁹ It found that the beneficial effect of blood pressure treatment depended on the patient’s baseline systolic blood pressure. In those with a baseline systolic pressure of 160 mm Hg or higher, treatment reduced cardiovascular mortality by about 15% (relative risk [RR] 0.85; 95% confidence interval [CI] 0.77–0.95). In patients with systolic pressure below 140 mm Hg, treatment effects were neutral (RR 1.03, 95% CI 0.87–1.20) and not associated with any benefit as primary prevention, although data suggest it may reduce the risk of adverse outcomes in patients with coronary heart disease.

OTHER TRIALS THAT INFLUENCED THE GUIDELINES

SPRINT was important for refining the appropriate targets for blood pressure treatment, but several other trials also influenced the ACC/AHA guidelines (Table 3).^20–24

SHEP and HYVET (the Systolic Hypertension in the Elderly Program²⁰ and the Hypertension in the Very Elderly Trial)²¹ supported intensive blood pressure treatment for older patients by reporting a reduction in fatal and nonfatal stroke risks for those with a systolic blood pressure above 160 mm Hg.

FEVER (the Felodipine Event Reduction study)²² found that treatment with a calcium channel blocker in even a low dose can significantly decrease cardiovascular events, cardiovascular disease, and heart failure compared with no treatment.

JATOS and VALISH (the Japanese Trial to Assess Optimal Systolic Blood Pressure in Elderly Hypertensive Patients²³ and the Valsartan in Elderly Isolated Systolic Hypertension study)²⁴ found that outcomes were similar with intensive vs standard treatment.

Ettehad et al²⁵ performed a meta-analysis of 123 studies with more than 600,000 participants that provided strong evidence supporting blood pressure treatment goals below 130/90 mm Hg, in line with the SPRINT trial results.

BLOOD PRESSURE ISN’T EVERYTHING

Other trials remind us that although blood pressure is important, it is not the only factor affecting cardiovascular risk.

HOPE (the Heart Outcomes Prevention Evaluation)²⁶ investigated the use of ramipril (an ACE inhibitor) in preventing myocardial infarction, stroke, or cardiovascular death in patients at high risk of cardiovascular events. The study included 9,297 participants over age 55 (mean age 66) with a baseline blood pressure 139/79 mm Hg. Follow-up was 4.5 years.

Ramipril was better than placebo, with significantly fewer patients experiencing adverse end points in the ramipril group compared with the placebo group:

• Myocardial infarction 9.9% vs 12.3%, RR 0.80, P < .001
• Cardiovascular death 6.1% vs 8.1%, RR  0.74, P < .001
• Stroke 3.4% vs 4.9%, RR = .68, P < .001
• The composite end point 14.0% vs 17.8%, RR 0.78, P < .001).

Results were even better in the subset of patients who had diabetes.²⁷ However, the decrease in blood pressure attributable to anti­hypertensive therapy with ramipril was minimal (3–4 mm Hg systolic and 1–2 mm Hg diastolic). This slight change should not have been enough to produce significant differences in clinical outcomes, a major limitation of this trial. The investigators speculated that the positive results may be due to a class effect of ACE inhibitors.²⁶

HOPE 3^28–30 explored the effect of blood pressure- and cholesterol-controlling drugs on the same primary end points but in patients at intermediate risk of major cardiovascular events. Investigators randomized the 12,705 patients to 4 treatment groups:

• Blood pressure control with candesartan (an ARB) plus hydrochlorothiazide (a thiazide diuretic)
• Cholesterol control with rosuvastatin (a statin)
• Blood pressure plus cholesterol control
• Placebo.

Therapy was started at a systolic blood pressure above 140 mm Hg.

Compared with placebo, the rate of composite events was significantly reduced in the rosuvastatin group (3.7% vs 4.8%, HR 0.76, P = .002)²⁸ and the candesartan-hydrochlorothiazide-rosuvastatin group (3.6% vs 5.0%, HR 0.71; P = .005)²⁹ but not in the candesartan-hydrochlorothiazide group (4.1% vs 4.4%; HR 0.93; P = .40).³⁰

In addition, a subgroup analysis comparing active treatment vs placebo found a significant reduction in major cardiovascular events for treated patients whose baseline systolic blood pressure was in the upper third (> 143.5 mm Hg, mean 154.1 mm Hg), while treated patients in the lower middle and lower thirds had no significant reduction.³⁰

These results suggest that intensive treatment to achieve a systolic blood pressure below 140 mm Hg in patients at intermediate risk may not be helpful. Nevertheless, there seems to be agreement that intensive treatment generally leads to a reduction in cardiovascular events. The results also show the benefit of lowering cholesterol.

Bundy et al³¹ performed a meta-analysis that provides support for intensive antihypertensive treatment. Reviewing 42 clinical trials in more than 144,000 patients, they found that treating to reach a target systolic blood pressure of 120 to 124 mm Hg can reduce cardiovascular events and all-cause mortality.

The trade-off is a minimal increase in the risk of adverse events. Also, the risk-benefit ratio of intensive treatment seems to vary in different patient subgroups.

 

WHAT ABOUT PATIENTS WITH COMORBIDITIES?

The debate over intensive vs standard treatment in blood pressure management extends beyond hypertension and includes important comorbidities such as diabetes, stroke, and renal disease. Patients with a history of stroke or end-stage renal disease have only a minimal mention in the AHA/ACC guidelines.

Diabetes

Emdin et al,³² in a meta-analysis of 40 trials that included more than 100,000 patients with diabetes, concluded that a 10-mm Hg lowering of systolic blood pressure significantly reduces the rates of all-cause mortality, cardiovascular disease, coronary heart disease, stroke, albuminuria, and retinopathy. Stratifying the results according to the systolic blood pressure achieved (≥ 130 or < 130 mm Hg), the relative risks of mortality, coronary heart disease, cardiovascular disease, heart failure, and albuminuria were actually lower in the higher stratum than in the lower.

ACCORD (the Action to Control Cardiovascular Risk in Diabetes)³³ study provides contrary results. It examined intensive and standard blood pressure control targets in patients with type 2 diabetes at high risk of cardiovascular events, using primary outcome measures similar to those in SPRINT. It found no significant difference in fatal and nonfatal cardiovascular events between the intensive and standard blood pressure target arms.

Despite those results, the ACC/AHA guidelines still advocate for more intensive treatment (goal < 130/80 mm Hg) in all patients, including those with diabetes.¹

The ADA position statement (September 2017) recommended a target below 140/90 mm Hg in patients with diabetes and hypertension.⁸ However, they also noted that lower systolic and diastolic blood pressure targets, such as below 130/80 mm Hg, may be appropriate for patients at high risk of cardiovascular disease “if they can be achieved without undue treatment burden.”⁸ Thus, it is not clear which blood pressure targets in patients with diabetes are the best.

Stroke

In patients with stroke, AHA/ACC guidelines¹ recommend treatment if the blood pressure is 140/90 mm Hg or higher because antihypertensive therapy has been associated with a decrease in the recurrence of transient ischemic attack and stroke. The ideal target blood pressure is not known, but a goal of less than 130/80 mm Hg may be reasonable.

In the Secondary Prevention of Small Subcortical Strokes (SPS3) trial, a retrospective open-label trial, a target blood pressure below 130/80 mm Hg in patients with a history of lacunar stroke was associated with a lower risk of intracranial hemorrhage, but the difference was not statistically significant.³⁴ For this reason, the ACC/AHA guidelines consider it reasonable to aim for a systolic blood pressure below 130 mm Hg in these patients.¹

Renal disease

The ACC/AHA guidelines do not address how to manage hypertension in patients with end-stage renal disease, but for patients with chronic kidney disease they recommend a blood pressure target below 130/80 mm Hg.¹ This recommendation is derived from the SPRINT trial,¹⁵ in which patients with stage 3 or 4 chronic kidney disease accounted for 28% of the study population. In that subgroup, intensive blood pressure control seemed to provide the same benefits for reduction in cardiovascular death and all-cause mortality.

TREAT PATIENTS, NOT NUMBERS

Blood pressure targets should be applied in the appropriate clinical context and on a patient-by-patient basis. In clinical practice, one size does not always fit all, as special cases exist.

For example, blood pressure can oscillate widely in patients with autonomic nerve disorders, making it difficult to strive for a specific target, especially an intensive one. Thus, it may be necessary to allow higher systolic blood pressure in these patients. Similarly, patients with diabetes or chronic kidney disease may be at higher risk of kidney injury with more intensive blood pressure management.

Treating numbers rather than patients may result in unbalanced patient care. The optimal approach to blood pressure management relies on a comprehensive risk factor assessment and shared decision-making with the patient before setting specific blood pressure targets.

OUR APPROACH

We aim for a blood pressure goal below 130/80 mm Hg for all patients with cardiovascular disease, according to the AHA/ACC guidelines. We aim for that same target in patients without cardiovascular disease but who have an elevated estimated cardiovascular risk (> 10%) over the next 10 years.

We recognize, however, that the benefits of aggressive blood pressure reduction may not be as clear in all patients, such as those with diabetes. We also recognize that some patient subgroups are at high risk of adverse events, including those with low diastolic pressure, chronic kidney disease, a history of falls, and older age. In those patients, we are extremely judicious when titrating antihypertensive medications. We often make smaller titrations, at longer intervals, and with more frequent laboratory testing and in-office follow-up.

Our process of managing hypertension through intensive blood pressure control to achieve lower systolic blood pressure targets requires a concerted effort among healthcare providers at all levels. It especially requires more involvement and investment from primary care providers to individualize treatment in their patients. This process has helped us to reach our treatment goals while limiting adverse effects of lower blood pressure targets.

MOVING FORWARD

Hypertension is a major risk factor for cardiovascular disease, and intensive blood pressure control has the potential to significantly reduce rates of morbidity and death associated with cardiovascular disease. Thus, a general consensus on the definition of hypertension and treatment goals is essential to reduce the risk of cardiovascular events in this large patient population.

Intensive blood pressure treatment has shown efficacy, but it has a small accompanying risk of adverse events, which varies in patient subgroups and affects the benefit-risk ratio of this therapy. For example, the cardiovascular benefit of intensive treatment is less clear in diabetic patients, and the risk of adverse events may be higher in older patients with chronic kidney disease.

Moving forward, more research is needed into the effects of intensive and standard treatment on patients of all ages, those with common comorbid conditions, and those with other important factors such as diastolic hypertension.

Finally, the various medical societies should collaborate on hypertension guideline development. This would require considerable planning and coordination but would ultimately be useful in creating a generalizable approach to hypertension management.

Vasovagal syncope is usually benign, and although it often recurs, increasing fluid and salt intake and performing counter-pressure maneuvers are usually sufficient.¹ However, if patients continue to have syncopal episodes despite these first-line measures, other options include drug therapy with midodrine, fludrocortisone, beta-blockers, or selective serotonin reuptake inhibitors; orthostatic training; and, in some cases, pacemaker implantation. The 2017 guidelines from the American College of Cardiology, American Heart Association, and Heart Rhythm Society (ACC/AHA/HRS) are helpful in the management of these patients.¹

RATIONALE

Although vasovagal syncope is considered benign, it can result in injury and can significantly affect quality of life.

The diagnosis can often be established in the initial evaluation with a structured history, physical examination, and electrocardiography. If the diagnosis is still unclear, tilt-table testing can be useful and has an ACC/AHA/HRS class IIa (moderate) recommendation.¹ Once the diagnosis of vasovagal syncope is made, first-line measures can be instituted.

FIRST-LINE MEASURES

An explanation of the diagnosis, education on avoiding triggers such as prolonged standing and warm environments, coping with potentially stressful visits to the doctor or dentist, and reassurance that the condition is benign are all strongly recommended (class I).¹

Initial measures include performing physical counter-pressure maneuvers (class IIa), increasing salt and fluid intake (class IIb) in the absence of contraindications, and, in selected patients, reducing or withdrawing hypotensive medications when appropriate (class IIb).

Physical counter-pressure maneuvers are recommended for patients whose syncopal episodes have a sufficiently long prodromal period. Maneuvers include the following:

• Leg crossing: crossing the legs while tensing leg, abdominal, and buttock muscles
• Handgrip: maximally contracting a rubber ball or other object in the dominant hand
• Squatting
• Limb or abdominal contractions
• Arm tensing: contracting both arms by gripping one hand with the other and abducting both arms.²

The effectiveness of counter-pressure maneuvers was studied by van Dijk et al² in a multicenter prospective randomized clinical trial that included 223 patients with recurrent vasovagal syncope associated with prodromal symptoms. They concluded that these maneuvers decreased the recurrence of syncopal episodes, with a relative risk reduction of 0.36 (95% confidence interval 0.11–0.53, P < .005) and were low-cost and risk-free.

Confirming the diagnosis of vasovagal syncope with tilt-table testing may reassure the patient. It can also help the patient learn to identify the symptoms associated with a vasovagal episode, which in turn may encourage timely use of physical counter-pressure maneuvers at the onset.

The evidence for increasing salt and fluid intake for patients with vasovagal syncope is limited. But in the absence of a contraindication such as hypertension, renal disease, or heart failure, it may be reasonable to encourage the ingestion of 2 L to 3 L of fluid per day and a total of 6 g to 9 g of salt per day (around 1 to 2 heaping teaspoons of salt).¹

 

 

MEDICAL THERAPY

In patients who continue to have syncopal episodes despite adequate use of first-line measures, medical therapy can be considered. Unfortunately, evidence supporting drug therapy for recurrent syncope is limited.³ Options include midodrine (class IIa), fludrocortisone (class IIb), beta-blockers (class IIb), and selective serotonin reuptake inhibitors (class IIb).¹

Midodrine has the strongest recommendation and is a reasonable option if there is no history of hypertension, heart failure, or urinary retention. It is a peripheral alpha-agonist that ameliorates the reduction in peripheral sympathetic neural outflow responsible for venous pooling and vasodepression in vasovagal syncope.^4–6

Fludrocortisone results in increased blood volume due to mineralocorticoid activity. In the Prevention of Syncope Trial 2 of fludrocortisone vs placebo, patients on fludrocortisone had a “marginally nonsignificant” reduction in recurrence of syncope over 1 year (hazard ratio 0.69, P = .069).⁷

Overall, beta-blockers have failed to prevent syncope in randomized controlled trials. But in a meta-analysis that included patients from the Prevention of Syncope Trial,⁸ an age-dependent benefit of beta-blockers was noted in patients age 42 and older.⁹ Therefore, a beta-blocker may be a reasonable option in patients in this age group with recurrent vasovagal syncope.¹

Table 1 shows current dosing recommendations for midodrine, fludrocortisone, and a beta-blocker.

Serotonin has central effects on blood pressure and heart rate that can induce syncope. However, evidence for the effectiveness of selective serotonin reuptake inhibitors in the prevention of recurrent vasovagal syncope has been contradictory in small trials.^10,11

When choosing a drug, contraindications should be considered, including possible effects during pregnancy in women of childbearing age.

OTHER MEASURES

Orthostatic training, with repetitive tilt-table testing until a test is negative, or with daily standing quietly against a wall for prolonged periods of time, has not been shown to have sustained benefit in reducing the recurrence of syncopal episodes (class IIb recommendation).¹

Dual-chamber pacing can be considered in carefully selected patients age 40 or older with syncope and documented asystole of at least 3 seconds or spontaneous pauses of at least 6 seconds without syncope on implantable loop recorder monitoring (class IIb recommendation).^1,12,13 Strict patient selection increases the likelihood that pacing will be effective.¹ For example, patients with documented asystole during syncope and a tilt-table test that induces minimal or no vasodepressor response are more likely to respond than patients with a positive tilt-table test with a vasodepressor (hypotensive) response.¹³

Tilt-table testing may also be considered to identify patients with a hypotensive response who would be less likely to respond to permanent cardiac pacing.¹⁴ 


Compression garments carry a class IIa recommendation for orthostatic hypotension,1 but they have not been adequately studied in vasovagal syncope.

Vasovagal syncope is usually benign, and although it often recurs, increasing fluid and salt intake and performing counter-pressure maneuvers are usually sufficient.¹ However, if patients continue to have syncopal episodes despite these first-line measures, other options include drug therapy with midodrine, fludrocortisone, beta-blockers, or selective serotonin reuptake inhibitors; orthostatic training; and, in some cases, pacemaker implantation. The 2017 guidelines from the American College of Cardiology, American Heart Association, and Heart Rhythm Society (ACC/AHA/HRS) are helpful in the management of these patients.¹

RATIONALE

Although vasovagal syncope is considered benign, it can result in injury and can significantly affect quality of life.

The diagnosis can often be established in the initial evaluation with a structured history, physical examination, and electrocardiography. If the diagnosis is still unclear, tilt-table testing can be useful and has an ACC/AHA/HRS class IIa (moderate) recommendation.¹ Once the diagnosis of vasovagal syncope is made, first-line measures can be instituted.

FIRST-LINE MEASURES

An explanation of the diagnosis, education on avoiding triggers such as prolonged standing and warm environments, coping with potentially stressful visits to the doctor or dentist, and reassurance that the condition is benign are all strongly recommended (class I).¹

Initial measures include performing physical counter-pressure maneuvers (class IIa), increasing salt and fluid intake (class IIb) in the absence of contraindications, and, in selected patients, reducing or withdrawing hypotensive medications when appropriate (class IIb).

Physical counter-pressure maneuvers are recommended for patients whose syncopal episodes have a sufficiently long prodromal period. Maneuvers include the following:

• Leg crossing: crossing the legs while tensing leg, abdominal, and buttock muscles
• Handgrip: maximally contracting a rubber ball or other object in the dominant hand
• Squatting
• Limb or abdominal contractions
• Arm tensing: contracting both arms by gripping one hand with the other and abducting both arms.²

The effectiveness of counter-pressure maneuvers was studied by van Dijk et al² in a multicenter prospective randomized clinical trial that included 223 patients with recurrent vasovagal syncope associated with prodromal symptoms. They concluded that these maneuvers decreased the recurrence of syncopal episodes, with a relative risk reduction of 0.36 (95% confidence interval 0.11–0.53, P < .005) and were low-cost and risk-free.

Confirming the diagnosis of vasovagal syncope with tilt-table testing may reassure the patient. It can also help the patient learn to identify the symptoms associated with a vasovagal episode, which in turn may encourage timely use of physical counter-pressure maneuvers at the onset.

The evidence for increasing salt and fluid intake for patients with vasovagal syncope is limited. But in the absence of a contraindication such as hypertension, renal disease, or heart failure, it may be reasonable to encourage the ingestion of 2 L to 3 L of fluid per day and a total of 6 g to 9 g of salt per day (around 1 to 2 heaping teaspoons of salt).¹

 

 

MEDICAL THERAPY

In patients who continue to have syncopal episodes despite adequate use of first-line measures, medical therapy can be considered. Unfortunately, evidence supporting drug therapy for recurrent syncope is limited.³ Options include midodrine (class IIa), fludrocortisone (class IIb), beta-blockers (class IIb), and selective serotonin reuptake inhibitors (class IIb).¹

Midodrine has the strongest recommendation and is a reasonable option if there is no history of hypertension, heart failure, or urinary retention. It is a peripheral alpha-agonist that ameliorates the reduction in peripheral sympathetic neural outflow responsible for venous pooling and vasodepression in vasovagal syncope.^4–6

Fludrocortisone results in increased blood volume due to mineralocorticoid activity. In the Prevention of Syncope Trial 2 of fludrocortisone vs placebo, patients on fludrocortisone had a “marginally nonsignificant” reduction in recurrence of syncope over 1 year (hazard ratio 0.69, P = .069).⁷

Overall, beta-blockers have failed to prevent syncope in randomized controlled trials. But in a meta-analysis that included patients from the Prevention of Syncope Trial,⁸ an age-dependent benefit of beta-blockers was noted in patients age 42 and older.⁹ Therefore, a beta-blocker may be a reasonable option in patients in this age group with recurrent vasovagal syncope.¹

Table 1 shows current dosing recommendations for midodrine, fludrocortisone, and a beta-blocker.

Serotonin has central effects on blood pressure and heart rate that can induce syncope. However, evidence for the effectiveness of selective serotonin reuptake inhibitors in the prevention of recurrent vasovagal syncope has been contradictory in small trials.^10,11

When choosing a drug, contraindications should be considered, including possible effects during pregnancy in women of childbearing age.

OTHER MEASURES

Orthostatic training, with repetitive tilt-table testing until a test is negative, or with daily standing quietly against a wall for prolonged periods of time, has not been shown to have sustained benefit in reducing the recurrence of syncopal episodes (class IIb recommendation).¹

Dual-chamber pacing can be considered in carefully selected patients age 40 or older with syncope and documented asystole of at least 3 seconds or spontaneous pauses of at least 6 seconds without syncope on implantable loop recorder monitoring (class IIb recommendation).^1,12,13 Strict patient selection increases the likelihood that pacing will be effective.¹ For example, patients with documented asystole during syncope and a tilt-table test that induces minimal or no vasodepressor response are more likely to respond than patients with a positive tilt-table test with a vasodepressor (hypotensive) response.¹³

Tilt-table testing may also be considered to identify patients with a hypotensive response who would be less likely to respond to permanent cardiac pacing.¹⁴ 


Compression garments carry a class IIa recommendation for orthostatic hypotension,1 but they have not been adequately studied in vasovagal syncope.

Vasovagal syncope is usually benign, and although it often recurs, increasing fluid and salt intake and performing counter-pressure maneuvers are usually sufficient.¹ However, if patients continue to have syncopal episodes despite these first-line measures, other options include drug therapy with midodrine, fludrocortisone, beta-blockers, or selective serotonin reuptake inhibitors; orthostatic training; and, in some cases, pacemaker implantation. The 2017 guidelines from the American College of Cardiology, American Heart Association, and Heart Rhythm Society (ACC/AHA/HRS) are helpful in the management of these patients.¹

RATIONALE

Although vasovagal syncope is considered benign, it can result in injury and can significantly affect quality of life.

The diagnosis can often be established in the initial evaluation with a structured history, physical examination, and electrocardiography. If the diagnosis is still unclear, tilt-table testing can be useful and has an ACC/AHA/HRS class IIa (moderate) recommendation.¹ Once the diagnosis of vasovagal syncope is made, first-line measures can be instituted.

FIRST-LINE MEASURES

An explanation of the diagnosis, education on avoiding triggers such as prolonged standing and warm environments, coping with potentially stressful visits to the doctor or dentist, and reassurance that the condition is benign are all strongly recommended (class I).¹

Initial measures include performing physical counter-pressure maneuvers (class IIa), increasing salt and fluid intake (class IIb) in the absence of contraindications, and, in selected patients, reducing or withdrawing hypotensive medications when appropriate (class IIb).

Physical counter-pressure maneuvers are recommended for patients whose syncopal episodes have a sufficiently long prodromal period. Maneuvers include the following:

• Leg crossing: crossing the legs while tensing leg, abdominal, and buttock muscles
• Handgrip: maximally contracting a rubber ball or other object in the dominant hand
• Squatting
• Limb or abdominal contractions
• Arm tensing: contracting both arms by gripping one hand with the other and abducting both arms.²

The effectiveness of counter-pressure maneuvers was studied by van Dijk et al² in a multicenter prospective randomized clinical trial that included 223 patients with recurrent vasovagal syncope associated with prodromal symptoms. They concluded that these maneuvers decreased the recurrence of syncopal episodes, with a relative risk reduction of 0.36 (95% confidence interval 0.11–0.53, P < .005) and were low-cost and risk-free.

Confirming the diagnosis of vasovagal syncope with tilt-table testing may reassure the patient. It can also help the patient learn to identify the symptoms associated with a vasovagal episode, which in turn may encourage timely use of physical counter-pressure maneuvers at the onset.

The evidence for increasing salt and fluid intake for patients with vasovagal syncope is limited. But in the absence of a contraindication such as hypertension, renal disease, or heart failure, it may be reasonable to encourage the ingestion of 2 L to 3 L of fluid per day and a total of 6 g to 9 g of salt per day (around 1 to 2 heaping teaspoons of salt).¹

 

 

MEDICAL THERAPY

In patients who continue to have syncopal episodes despite adequate use of first-line measures, medical therapy can be considered. Unfortunately, evidence supporting drug therapy for recurrent syncope is limited.³ Options include midodrine (class IIa), fludrocortisone (class IIb), beta-blockers (class IIb), and selective serotonin reuptake inhibitors (class IIb).¹

Midodrine has the strongest recommendation and is a reasonable option if there is no history of hypertension, heart failure, or urinary retention. It is a peripheral alpha-agonist that ameliorates the reduction in peripheral sympathetic neural outflow responsible for venous pooling and vasodepression in vasovagal syncope.^4–6

Fludrocortisone results in increased blood volume due to mineralocorticoid activity. In the Prevention of Syncope Trial 2 of fludrocortisone vs placebo, patients on fludrocortisone had a “marginally nonsignificant” reduction in recurrence of syncope over 1 year (hazard ratio 0.69, P = .069).⁷

Overall, beta-blockers have failed to prevent syncope in randomized controlled trials. But in a meta-analysis that included patients from the Prevention of Syncope Trial,⁸ an age-dependent benefit of beta-blockers was noted in patients age 42 and older.⁹ Therefore, a beta-blocker may be a reasonable option in patients in this age group with recurrent vasovagal syncope.¹

Table 1 shows current dosing recommendations for midodrine, fludrocortisone, and a beta-blocker.

Serotonin has central effects on blood pressure and heart rate that can induce syncope. However, evidence for the effectiveness of selective serotonin reuptake inhibitors in the prevention of recurrent vasovagal syncope has been contradictory in small trials.^10,11

When choosing a drug, contraindications should be considered, including possible effects during pregnancy in women of childbearing age.

OTHER MEASURES

Orthostatic training, with repetitive tilt-table testing until a test is negative, or with daily standing quietly against a wall for prolonged periods of time, has not been shown to have sustained benefit in reducing the recurrence of syncopal episodes (class IIb recommendation).¹

Dual-chamber pacing can be considered in carefully selected patients age 40 or older with syncope and documented asystole of at least 3 seconds or spontaneous pauses of at least 6 seconds without syncope on implantable loop recorder monitoring (class IIb recommendation).^1,12,13 Strict patient selection increases the likelihood that pacing will be effective.¹ For example, patients with documented asystole during syncope and a tilt-table test that induces minimal or no vasodepressor response are more likely to respond than patients with a positive tilt-table test with a vasodepressor (hypotensive) response.¹³

Tilt-table testing may also be considered to identify patients with a hypotensive response who would be less likely to respond to permanent cardiac pacing.¹⁴ 


Compression garments carry a class IIa recommendation for orthostatic hypotension,1 but they have not been adequately studied in vasovagal syncope.