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

Abstract

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. 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. 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). 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.