Neutrophil to lymphocyte ratio as a predictor of long-term mortality in African Americans undergoing percutaneous coronary intervention

Abstract

Background: Neutrophil to lymphocyte ratio (N/L ratio) has been shown to predict long-term mortality in patients undergoing percutaneous coronary intervention (PCI). African Americans have been shown to have lower mean neutrophil counts compared to whites. The usefulness of the N/L ratio in predicting long-term mortality in African Americans undergoing PCI is unknown. Methods: We evaluated a total of 372 African American patients (327 patientswith lower N/L ratio [<3.5] and 45 patientswith higher N/L ratio [≥3.5]) who underwent PCI during January 2003 to August 2005. The primary endpoint was all-cause mortality at a median follow-up to 3.6 years. Results: During the median (± SD) follow-up period of 3.6 ± 1 years, there were a total of 48 deaths. The mortality rate was 10.4% in the group with a lower N/L ratio and 31.1% in the group with a higher N/L ratio (unadjusted p<0.001). After adjustment for covariateswith significant impact on mortality, N/L ratio was still a strong and independent predictor of long-term mortality with a hazard ratio (HR) of 2.1 (95% confidence interval [CI]: 1.1-4; p = 0.02). N/L ratio was also found to be a strong and independent predictor of long-term mortality even when analyzed as a categorical variable with 3 groups (HR of 0.39 for lower tertile compared to the upper tertile, 95% CI: 0.19-0.81; p = 0.012) and as a continuous variable (p = 0.002). Conclusion: N/L ratio is a powerful independent predictor of long-term mortality in African Americans undergoing PCI. © 2009 Wiley Periodicals, Inc.