Long-Term Survival of African Americans in the Coronary Artery Surgery Study (CASS)

Abstract

Objectives. This study sought to determine the long-term (>15 years) outcome of a clinically well characterized cohort of African Americans with known or suspected coronary artery disease (CAD).Background. The mortality rate from CAD is higher in African Americans than in whites. An earlier analysis of data from the Coronary Artery Surgery Study (CASS) registry suggested that African American and white patients treated surgically had equal 5-year survival rates.Methods. Survival data from the CASS registry were analyzed to determine whether 1) African American race is an independent predictor of mortality; and 2) initial therapy is predictive of mortality among African American patients.Results. Overall, 60% of white and 52% of African American patients survived 16 years (p < 0.00001). Multivariate Cox models confirmed that African American race was independently associated with higher mortality in both the medical group (hazard ratio [HR] 1.34, 95% confidence interval [CI] 1.11 to 1.63) and the surgical group (HR 1.63, 95% CI 1.19 to 2.23). Initial therapy was not predictive of survival among African American patients (p = 0.81). However, smoking status significantly influenced survival: African Americans who did not smoke experienced significantly improved survival (60% vs. 48% for smokers), which equaled survival for white nonsmokers (61%, p = NS).Conclusions. In contrast to results from shorter term studies, African Americans experienced higher overall mortality rates than whites over the long term, regardless of the type of initial treatment. Survival among nonsmoking African Americans at 16 years equaled survival among nonsmoking whites.(J Am Coll Cardiol 1997;29:358–64)