Surveillance study of diltiazem use in black and nonblack angina patients.

Diltiazem hydrochloride was studied in 133 patients with angina to determine whether differing effects were produced in black patients (39 percent of patients) as compared with nonblack patients. The antihypertensive effect of the drug was also assessed. No statistically significant differences between the responses of blacks and nonblacks were found in the reduction of angina frequency (54 percent of blacks improved, 58 percent of nonblacks), nitroglycerin consumption (60 percent of blacks used less, 66 percent of nonblacks), and changes in lifestyle, as measured with the New York Heart Association scale (55 percent of blacks improved, 63 percent of nonblacks). The antihypertensive effects (not analyzed by race) were greatest in patients with uncontrolled hypertension. Average decreases in this group were 18 mmHg in supine systolic pressures and 14 mmHg in supine diastolic pressures, as compared with decreases of only 4 and 3 mmHg in normotensives. Study results suggest that there is a difference in the type of angina afflicting blacks and nonblacks, that hypertension more often accompanies angina in blacks, and that diltiazem is equally effective in treating angina in blacks and nonblacks.