say the authors of a new state-of-the-art review.
“CVD and obesity are common conditions that frequently coexist. We cannot treat one of these conditions while ignoring the other,” Rosana G. Bianchettin, MD, of the division of cardiovascular diseases, Mayo Clinic, Rochester, Minn., and colleagues wrote in their review, recently published in the Journal of the American College of Cardiology.
The review outlines, for example, how obesity can impair common imaging tests used to diagnose heart disease, potentially reducing their accuracy.
And cardiac procedures such as percutaneous coronary intervention, open heart surgery, and revascularization all involve greater risk in the setting of obesity, while procedures such as valve replacement and heart transplantation carry a greater likelihood of failure.
Obesity can also alter drug pharmacokinetics and pharmacodynamics.
Weight reduction is an important part of the management of patients with cardiovascular disease and obesity, and “cardiac rehabilitation programs represent a potential opportunity for structured interventions,” the authors noted. However, “when other measures are insufficient, bariatric surgery can improve outcomes.”
They also advised against relying solely on body mass index (BMI) to assess adiposity: “It is prudent to investigate a range of complementary ... parameters alongside standard BMI calculations (accounting for age, race, and sex), including measures of central obesity, such as waist circumference, waist-to-hip ratio, and weight-to-height ratio.”
Excess fat acts as filter and can skew diagnostic results
“Obesity affects nearly all the diagnostic tests used in cardiology, such as ECG, CT scan, MRI, and echocardiogram,” senior author Francisco Lopez-Jimenez, MD, director of preventive cardiology at Mayo Clinic, explained in a statement.
The review includes a detailed table of these key obesity-related challenges. With electrocardiograms, for example, obesity can cause displacement of the heart, increased cardiac workload, and widening of the distance between the heart and the recording electrodes.
Obesity also lowers the sensitivity of exercise echocardiography, and use of CT coronary angiogram is completely precluded in people with a BMI above 40 kg/m2. In interventional radiology, there may be poor visualization of target areas.
“Excess fat acts as a kind of filter and can skew test readings to under- or overdiagnosis,” noted Dr. Lopez-Jimenez.
Therapeutic challenges: Drugs may work differently
A longer table in the review summarizes the therapeutic challenges involved in lifestyle modification, pharmacology, cardiac procedures, and other therapeutic measures for people with the two conditions.
Obesity can limit a person’s ability to exercise, for example, and smoking cessation may promote overeating and further weight gain.
Moreover, “tailoring pharmacotherapy is difficult because of unique pharmacokinetic and pharmacodynamic factors in people with obesity that alter distribution, metabolism, and elimination of drugs. Each drug also has special properties that must be considered when it is administrated,” the authors wrote.
Examples include the higher volume of distribution of lipophilic drugs in those with increased fat mass, alterations in liver metabolism, and difficulties with anticoagulant dosing.
Cardiac rehabilitation is an intervention opportunity
Although cardiac rehabilitation is “a cornerstone in secondary prevention” for people who have experienced a cardiac event, only 8% of such programs include formal in-house behavioral weight-loss programs.
But that could be remedied and expanded with the use of options such as home-based rehabilitation and telephone counseling, particularly in rural communities, Dr. Bianchettin and colleagues said.
“Motivated individuals will benefit from multicomponent approaches and should be encouraged to set specific, proximal, shared goals with their health care professional. A multitude of tools are available to support self-monitoring (e.g., smartphone applications, food diaries), and scheduled regular follow-up and feedback on progress can help to maintain motivation,” they wrote.
The bottom line, said Dr. Lopez-Jimenez: “Obesity is an important risk factor to address in patients with heart disease and it requires us to do something. ... The patient needs to know that their clinician can help them lose weight. Overall, weight-loss solutions come down to finding the right therapy for the patient.”
Dr. Bianchettin reported no relevant financial relationships. Dr. Lopez-Jimenez has reported conducting research related to 3D body assessment with Select Research, Mayo Clinic, and may benefit in the future if the technology is commercialized; he has not received any relevant monetary, financial, or other type of compensation to date, in relationship to this arrangement. He is a member of the scientific advisory board for Novo Nordisk.
A version of this article first appeared on Medscape.com.