Predictive value of neutrophil to lymphocyte ratio in clinical outcomes of non-ST elevation myocardial infarction and unstable angina pectoris: 3-years follow-up

Abstract

Background: Neutrophil to lymphocyte (NLR) is the strongest white blood cell predictor of adverse outcomes for stable coronary artery disease and mortality in patients presenting with ST-segment elevation myocardial infarction. We sought to determine the prognostic value of NLR in non-ST elevation myocardial infarction (NSTEMI) and unstable angina pectoris (UAP). Methods: A total of 308 (mean age 59.22±11.93; 234 males, 74 females) patients with NSTEMI and UAP were prospectively evaluated. Admission NLR was measured as part of the automated complete blood count. The study population was divided into tertiles based on admission NLR values. A high NLR (n=102) was defined as a value in the third tertile (>3.04), and a low NLR (n=206) was defined as a value in the lower two tertiles (≤3.04). Patients were followed for clinical outcomes for up to 3-years after discharge. Results: Kaplan-Meier survival analysis showed 3-years mortality rate of 21.6% in patients with high NLR versus 3% in low NLR group (p<0.001). In a receiver operating characteristic curve analysis, a NLR value of 3.04 identified as an effective cut-point in NSTEMI and UAP of 3-years cardiovascular mortality (area under curve=0.86, 95% confidence interval 0.8 to 0.92). A NLR value of >3.04 yielded a sensitivity of 79%, a specificity of 71%. We used Cox proportional hazard models to examine the association between NLR and adverse clinical outcomes. A significant association was noted between high admission NLR level and the adjusted risk of cardiovascular mortality (hazard ratio: 6.3, 95% confidence interval:1.6-24.3, p=0.008). There was a good correlation between NLR levels and age (r:0.22, p<0.001), TIMI risk score (r:0.153, p<0.001), and GRACE risk score (r:0.284, p<0.001). Conclusion: Admission NLR is strong, and independent predictor of 3-years cardiovascular mortality in patients with NSTEMI and UAP.