Lessons on the interaction of race and antihypertensive drugs from the VA cooperative study group on antihypertensive agents.

The Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents, organized by Dr. Edward D. Freis, has made numerous contributions to our knowledge about hypertension and its treatment. In the late 1970s the group observed post hoc that there were racial differences in response to hydrochlorothiazide and propranolol. Subsequent studies were designed to seek out racial differences if they existed. A series of observations led to the design of a comparative study of six drugs and placebo used as single-drug therapy of mild to moderate hypertension in men. Further analyses of those data have indicated that racial differences still exist when a second drug is substituted for a failed first drug. A combination of two drugs that had previously failed to achieve control of blood pressure did produce control in 58% of the patients. Electrocardiographic data suggested that black patients were much more likely to have left ventricular hypertropy (LVH) than whites, but analysis of echocardiograms showed that there was no racial difference in the prevalence of LVH. Additional analyses are in progress addressed to serum lipid changes, proteinuria, and drug-induced changes in left ventricular mass.