Tabriz University of Medical Sciences Journal of Cardiovascular and Thoracic Research 2008-5117 13 2 2021 05 22 Performance of neutrophil to lymphocyte ratio for the prediction of long-term morbidity and mortality in coronary slow flow phenomenon patients presented with non-ST segment elevation acute coronary syndrome 125 130 10.34172/jcvtr.2021.12 EN Ahmet Zengin https://orcid.org/0000-0002-6823-2305 Mehmet Karaca Emre Aruğaslan Ersin Yıldırım Mehmet Baran Karataş Yiğit Çanga Ayşe Emre Gülşah Tayyareci Journal Article 10.34172/jcvtr.2021.12 2020 06 08 2020 12 18 Introduction: In this study, we aimed to determine if neutrophil to lymphocyte ratio could predict long term morbidity and mortality in patients who hospitalized for non-ST segment elevation acute coronary syndrome (NSTE-ACS) and had coronary slow flow on coronary angiography. Methods: In this observational study, 111 patients who presented with NSTE-ACS and diagnosed with coronary slow flow phenomenon on angiographic examination were included. Neutrophil to lymphocyte ratio (NLR) calculated as the ratio of the number of neutrophils to the number of lymphocytes. Patients classified into three groups according to NLR values. The term coronary slow flow phenomenon was depicted by calculating Thrombolysis in Myocardial Infarction frame count.Patients were followed up and the occurrence of recurrent angina, recurrent myocardial infarction, and long-term mortality was determined using medical records, phone calls, or face-to-face interviews. P values <0.05 considered to indicate statistical significance. Results: Recurrent angina and myocardial infarction occurred more frequently in the highest NLR tertile compared with middle and lowest NLR tertiles. High NLR group (NLR≥ 3.88 n=38) was significantly associated with younger age and smoking status. WBC, troponin I and CRP levels increased as the NLR tertile increased. Recurrent myocardial infarction and angina showed strong relationship with increasing NLR values. In multivariate regression analyses smoking and high NLR levels were independent predictors of recurrent myocardial infarction (HR:4.64 95%CI 0.95-22.52 P=0.04, HR: 1.48 95%CI 1.16-1.90 P<0.01 respectively) in the long term follow up. Conclusion: Our study demonstrated that high NLR values can be a valuable prognostic tool in the long term follow up of patients who presented with NSTE-ACS and diagnosed with slow flow phenomenon on coronary angiography.