Coronary heart disease mortality/morbidity and risk in blacks. I: Clinical manifestations and diagnostic criteria: the experience with the Beta Blocker Heart Attack Trial

Abstract

A comparison was made of the clinical manifestations and diagnostic criteria of coronary artery disease in black and nonblack patients in the cohort of participants in the Beta Blocker Heart Attack Trial (BHAT). Although diagnostic criteria were uniform for all potential participants in the trial, examination of the baseline data indicates that black patients had a higher proportion of cardiomegaly and ECGs with left ventricular hypertrophy with ST-T wave changes and a lower percentage of transmural myocardial infarction in comparison to nonblack patients. Baseline data also show that blacks, in comparison to nonblacks, had a higher percentage of variables shown to be characteristic of the high-risk group, including current smoking status, rapid heart rate, angina, high blood pressure, elevated cholesterol, diuretic use, and vasodilator use. The Cox regression analysis confirmed the positive association of these risk descriptors with outcome for the overall study. Walker-Duncan multivariate regression analysis ascribed significance of these risk descriptors to nonblacks only. Blacks (n = 333) had placebo and treatment mortality rates of 15.9 and 11.7, compared to 9.8 and 7.2, respectively, for the overall study (n = 3837). Thus the reduction in mortality among blacks who received propranolol after a recent myocardial infarction was shown to be comparable to that of the other high-risk groups in the BHAT.