Racial differences in long-term survival among patients with coronary artery disease

Background: Cardiovascular disease is the leading cause of death among blacks and whites in the United States. Despite this, there are insufficient data on the long-term prognosis of black patients with coronary artery disease (CAD) as well as the major clinical related determinants of outcome. Methods: We studied 22,618 patients (3,314 black) having significant CAD findings at cardiac catheterization performed at Duke from January 1986 to December 2004 with follow-up through June 2006. Using Kaplan-Meier and Cox modeling, we compared unadjusted and adjusted long-term survival by patient race and gender (median follow-up 7.6 years, interquartile range 3.5-13.0) as well as identified major patient characteristics associated with survival. Results: Blacks with CAD were younger; were more often female; had lower median household incomes; and had more hypertension, diabetes mellitus, and heart failure. The number of coronary vessels with significant disease was similar by race. At 15-year follow-up, black women had the lowest survival and white men had the highest (41.5% vs 45.8%, P < .0001). Blacks were less likely to receive initial therapy with coronary revascularization (odds ratio 0.66, 95% CI 0.60-0.72, P < .0001). After adjusting for baseline clinical and demographic characteristics and initial treatment selection, black race remained an independent predictor of lower survival (hazard ratio 2.54, 95% CI 1.60-4.04, P < .0001). Conclusions: Among patients with CAD, blacks have lower long-term survival compared with whites. The difference may be partially, but not fully, explained by differences in cardiovascular risk factors and 30-day revascularization rates.