Myocardial infarction in treated hypertensive patients: the paradox of lower incidence but higher mortality in young blacks compared with whites.

ABSTRACT

BACKGROUND: Despite the impressive decline in coronary heart disease death rates, a mortality differential between blacks and whites persists. Our study objective was to determine whether excess mortality among well-controlled hypertensive black men compared with whites is due to differences in disease incidence or in case fatality. METHODS AND RESULTS: Of 3382 male subjects (1266 blacks and 2116 whites) enrolled between 1973 and 1996 and followed up through 1997 in a work-site hypertension control program, 2343 were followed up until 60 years of age, and 1884 were followed up until >60 years of age (either continuing after 60 years [n=845] or beginning treatment at >/=60 years [n=1039]), with a mean follow-up of 5.2 and 5.5 years, respectively. During follow-up, 186 myocardial infarction (MI) events (including 31 revascularizations) occurred, with 63 in patients <60 years and 123 in patients >/=60 years of age. Age-adjusted MI incidence was nearly twice as high for whites as blacks in younger (6.3 versus 3.4/1000 person-years) and older (14.1 versus 7.5 person-years) subjects. In contrast, the age-adjusted case fatality rate was 3-fold higher for younger blacks than for whites (37.8% versus 12.2%). In older patients, case fatality did not differ significantly between blacks and whites (37.6% versus 50. 3%). In separate Cox regression analyses, among younger blacks but not younger whites, history of diabetes and smoking were significantly associated with both incidence and fatality. CONCLUSIONS: In these treated male hypertensive patients with good blood pressure control (139.6/85.7 mm Hg), young blacks, despite a lower MI incidence, had higher MI mortality than did their white counterparts. Their higher case fatality rate was associated with fewer coronary artery revascularizations and a higher prevalence of diabetes and smoking.