NEW YORK — Hypertension treatment for African Americans should begin at a blood pressure of 135/85 mm Hg, rather than the previously recommended 140/90 mm, according to forthcoming guidelines from the International Society on Hypertension in Blacks.
In addition, the guidelines now favor chlorthalidone as the preferred thiazide-like diuretic (not hydrochlorothiazide), with the initial dose at 25 mg per day, not 12 mg per day as previously recommended.
Perhaps most significantly, the guidelines call for the target BP levels to be seen by physicians as ceilings, not floors.
“We encourage you to drive the blood pressures significantly under the targets,” said Dr. John M. Flack, chairman of the working group that developed the International Society on Hypertension in Blacks (ISHIB) consensus statement on the management of hypertension in African Americans at the meeting “If you drive just to the target, the patient will oscillate above and below it.”
Current blood pressure control rates in African Americans remain poor, said Dr. Flack, professor of medicine and physiology and chairman of the department of internal medicine at Wayne State University, Detroit, as well as principal investigator of the university's Center for Urban and African American Health.
“We've had a slight improvement in control rates over the past decade, so we're trending in the right direction,” he said. But, he noted, recent studies have found that only 29.9% of non-Hispanic black men have their hypertension properly controlled, and 36.0% of black women.
What's more, death rates from hypertension remain more than double that of whites, he noted, accounting for 30% of deaths in hypertensive African American men, and 20% of hypertensive African American women.
The new guidelines stratify risk into primary and secondary prevention. Primary prevention applies to patients with a BP of at least 135/85 mm Hg without target-organ damage, or cardiovascular disease—even if the CVD is preclinical. Secondary prevention applies to those with BP of at least 130/80 and target-organ injury or any degree of cardiovascular disease.
By those risk stratums, the target BP level for primary prevention should be 135/85 mm Hg, or 130/80 mm Hg for secondary prevention.
Even if BP is at 115/75 mm Hg, comprehensive lifestyle modifications should be recommended: weight loss if overweight, dietary change (low fat, low sodium, high potassium, adequate calcium), a limit on alcohol, regular physical activity, and avoiding or stopping smoking.
The key therapeutic recommendations for primary prevention in patients with a BP less than 145/90 mm Hg are optional comprehensive lifestyle modifications for up to 3 months, and then antihypertensive drugs. Preferred agents are a thiazide diuretic or calcium channel blocker, with a RAS blocker as an alternative, and a beta-blocker as optional.
In primary prevention where the patient's blood pressure is greater than 15/10 above goal, two-drug therapy should be initiated, with the preferred combination being either a calcium channel blocker and RAS blocker or a thiazide and RAS blocker. The alternative would be a thiazide and beta-blocker or thiazide and calcium channel blocker. The optional combination would be a thiazide and aldosterone antagonist.
The key therapeutic recommendations for secondary prevention in which the patient's blood pressure is greater than 15/10 above goal would be combination therapy using drugs with compelling indications. If the patient's BP is less than 15/10 above goal, a single agent with a compelling indication would be used, with a diuretic or calcium channel blocker preferred; a RAS blocker as an alternative; and a beta-blocker as optional.
“There was a lot of debate about which drug lowers blood pressure more or less,” Dr. Flack said. But, he added, “Most African Americans are not going to hit target with a single drug, so the argument over which is best is largely irrelevant.”
The central point, he said, is that physicians need to work harder to bring their African Americans' BP levels below targets. “If these guidelines are implemented,” he said, “they will improve outcomes for our African American patients.”
Dr. Flack has received grants and research support from Merck & Co., Novartis, Pfizer Inc., GlaxoSmithKline, Astra Merck Inc., Astra Zeneca, Boehringer Mannheim Pharmaceuticals, Cardiodynamics, and Daiichi Sankyo Co. He has been a consultant to Merck, GlaxoSmithKline, Bristol-Myers Squibb, Novartis, CVRx Inc, and Myogen Inc.