Because cardiovascular disease (CVD) is one of the six key action areas of the federal initiative to eliminate racial and ethnic disparities in health by 2010, the development of new drugs for treating high blood pressure in minority populations has become a major priority for many pharmaceutical companies. However, the results of the largest clinical study to date comparing the effectiveness of different hypertension treatments suggest that traditional, less costly diuretics actually work better than newer classes of drugs--such as calcium channel blockers, ACE inhibitors and alpha-adrenergic blockers--in lowering blood pressure and preventing some forms of CVD.
The ALLHAT study (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial), supported by the National Heart, Lung, and Blood Institute (NHLBI), was conducted at 623 clinical sites throughout the continental U.S., Puerto Rico, the Virgin Islands and eastern Canada. More than 42,000 people ages 55 and older with hypertension and at least one other CVD risk factor were enrolled in the long-term trial’s initial phase (February 1994 to March 2000). After that, more than 33,000 of the participants continued on in the study until its conclusion in March 2002; the average patient follow-up was five years.
In addition to its vast size, the ALLHAT study is a landmark because it provided an opportunity to examine the effects of different CVD prevention treatments on patient populations that had been underrepresented or excluded in previous clinical trials. Nearly one-half of the study participants were women, more than one-third were African American, about one-fifth were Hispanic and more than one-third had diabetes.
ALLHAT’s final results, published in the December 18, 2002 issue of The Journal of the American Medical Association, indicated that the diuretic chlorthalidone did a better job of preventing CVD events than three newer drugs: a calcium channel blocker (amlodipine), an ACE inhibitor (lisinopril) and an alpha-adrenergic blocker (doxazosin). Chlorthalidone’s effectiveness compared to lisinopril was especially remarkable in black patients. “Because of their superiority in preventing one or more major forms of CVD and their lower cost, thiazide-type diuretics should be the drugs of choice for initial treatment of hypertension in most patients requiring drug therapy,” the report concludes.
For more information about the results of the ALLHAT hypertension study, as well as a companion ALLHAT study that compared cholesterol-lowering treatments, visit www.nhlbi.nih.gov.