Neutrophil-to-Lymphocyte Ratio as a Predictor of In-Hospital Mortality and Complications in Acute Coronary Syndrome: A Cross-Sectional Study

Background Acute coronary syndrome (ACS) is a major cause of morbidity and mortality worldwide. Inflammation plays a key role in its pathogenesis, and the neutrophil-to-lymphocyte ratio (NLR) has emerged as a potential prognostic marker. This study aimed to evaluate its role in predicting in-hospital complications and mortality among patients admitted with ACS. Methods This hospital-based cross-sectional observational study included 103 patients admitted with ACS. Patients were categorized into two groups based on NLR: <7 (n = 57, 55.3%) and ≥7 (n = 46, 44.7%). Clinical parameters, laboratory findings, and outcomes, including complications, heart failure, arrhythmias, and mortality, were recorded and analyzed. Results Among the study participants, 76 (73.7%) were male and 27 (26.3%) were female, with the majority aged 40-60 years. Hypertension was present in 42 (40.7%) patients, and diabetes mellitus was present in 57 (55.4%) patients. Elevated NLR (≥7) was significantly associated with left ventricular dysfunction (38/63, 60.3%), compared to 8/40 (20.0%) in the low-NLR group (p < 0.001). Heart failure was more frequent in the high-NLR group (34/54, 63.0%) than in the low-NLR group (20/54, 37.0%) (p < 0.001). Arrhythmias were observed in 24/36 (66.7%) patients with high NLR, compared to 12/36 (33.3%) patients with low NLR (p = 0.001). Complications were significantly more common in patients with elevated NLR (43/46, 93.5%) than in those with lower NLR (40/57, 70.2%) (p = 0.003). Mortality was also significantly higher in the high-NLR group (21/27, 77.8%) than in the low-NLR group (6/27, 22.2%) (p < 0.001). Conclusion Elevated NLR is a strong predictor of adverse outcomes in ACS. It can serve as a simple and effective tool for early risk stratification and prognostication in clinical practice.