Effect of Hemoglobin Level on Long-Term All-Cause Mortality After Percutaneous Coronary Intervention in African-Americans

Abstract

Anemia has been shown to be an independent predictor of long-term mortality after percutaneous coronary intervention (PCI). African-Americans are known to have lower hemoglobin (Hgb) levels compared with Caucasians. The impact of anemia on long-term mortality in African-Americans undergoing PCI is unknown. We evaluated a total of 715 African-American patients (313 patients with anemia and 402 patients without anemia as defined by the World Health Organization [Hgb <13 g/dl for men and <12 g/dl for women]) using data from our bolus-only glycoprotein IIb/IIIa database. After a median follow-up of 3.2 years (interquartile range 2.4 to 3.8), there were a total of 72 (10%) deaths. Survival rate was 84% in the anemic group compared with 94% in the control group (hazard ratio [HR] 2.8, unadjusted p <0.001 by log-rank test). After adjustment for baseline clinical and procedural characteristics using a Cox proportional hazards model, Hgb as a dichotomous variable was a strong and independent predictor of all-cause mortality during the follow-up period (HR for death 2.0, 95% confidence interval 1.2 to 3.4, adjusted p = 0.012). Also, when Hgb was analyzed as a categorical variable having 3 groups with empirically determined cutoffs at <11.1, > or =11.1 to <12.7, and > or =12.7 g/dl, the effect remained significant (adjusted p = 0.008), with a HR of 2.3 for the group with lowest Hgb compared with the group with highest value (HR 2.6 for group with Hgb > or =11.1 to <12.7 compared with the group with the highest Hgb value). In conclusion, baseline Hgb is a strong and independent predictor of all-cause long-term mortality in African-Americans undergoing PCI.