title: 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 patients with lower N/L ratio [<3.5] and 45 patients with higher N/L ratio [> or =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 covariates with 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).
  
  
  CONCLUSIONS
  N/L ratio is a powerful independent predictor of long-term mortality in African Americans undergoing PCI.
authors.affiliation: Division of Cardiology, Department of Medicine, State University of New York, Downstate Medical Center, Brooklyn, New York, USA.
authors.forename: Shyam
authors.initials: S
authors.lastname: Poludasu
authors.forename: Erdal
authors.initials: E
authors.lastname: Cavusoglu
authors.forename: Waqas
authors.initials: W
authors.lastname: Khan
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Marmur
mesh_terms: D000789:Angina, Unstable / Q000097:blood / Q000401:mortality / Q000628:therapy; D015906:Angioplasty, Balloon, Coronary; D044383:Black People / Q000706:statistics & numerical data*; D003324:Coronary Artery Disease / Q000097:blood* / Q000401:mortality* / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D007958:Leukocyte Count; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000401:mortality / Q000628:therapy; D009504:Neutrophils / Q000166:cytology*; D012189:Retrospective Studies; D015607:Stents; D001741:Black or African American