Is the neutrophil-lymphocyte ratio a good marker for the differential diagnosis of unstable angina pectoris and non-ST elevation myocardial infarction?

Background: The aim of this study is to investigate the role of the neutrophil-lymphocyte ratio (NLR) in the differential diagnosis of non-ST elevation myocardial infarction (NSTEMI) and unstable angina pectoris (USAP). Material and Method: Patients who had been admitted to the emergency ward with complaints of chest pain and who were diagnosed with USAP and NSTEMI in further examination were retrospectively included in this study. The NLR level was measured for each patient both at the times of application and of discharge. The NLR was calculated by dividing the neutrophil count by the lymphocyte count. Results: WBC (8107.38±1405.5 vs 7452.46±1427.9, p: 0.020), neutrophil (5620 vs 4300, p: 0.001), and NLR (3.86 vs 2.14, p: 0.001) values were higher, whereas the lymphocyte value (1505 vs 2100, p: 0.001) was lower in the NSTEMI versus the USAP group. According to the multivariable logistic regression analysis that was done, NLR appeared to be an independent predictor of NSTEMI. The predictive value of NLR for NSTEMI diagnosis was >3.22 with 61.9% sensitivity and 86.96% specificity (74.3% positive predictive, 78.9% negative predictive) (AUC: 0.761; p< 0.001). Conclusion: As a cheap inexpensive and easy-to-calculate index that can be applied in every medical establishment within the first 20 minutes of application, it is possible to state that NLR is a good marker in distinguishing NSTEMI from USAP patients.