Association of Neutrophil‐to‐Lymphocyte and Platelet‐to‐Lymphocyte Ratios With Three‐Vessel Coronary Artery Disease: A Case‐Control Study

ABSTRACT Background and Aims Coronary artery disease (CAD) is a leading cause of mortality worldwide, with inflammation playing a crucial role in its pathogenesis. The neutrophil‐to‐lymphocyte ratio (NLR) and platelet‐to‐lymphocyte ratio (PLR) are emerging as potential inflammatory biomarkers for CAD severity. This study investigates the association of NLR and PLR with three‐vessel disease in patients undergoing elective coronary angiography. Methods A registry‐based case‐control study was conducted on 300 patients at Imam Hossein Hospital, Tehran, Iran. Patients were randomly divided into two groups of 150: (1) CAD patients with three‐vessel disease (≥ 50% stenosis) and (2) individuals with normal coronary angiograms. Demographic, clinical, and preoperative laboratory variables were compared between groups. Univariate and multivariable logistic regression analyses were performed to determine the predictive value of NLR and PLR. The models' performance was assessed using discrimination and calibration indices. Results Patients with three‐vessel CAD had a significantly higher prevalence of NLR ( ≥ 2.5) and PLR ( ≥ 130) than those with normal coronary arteries ( p < 0.05). NLR ≥ 2.5 was independently associated with a 91% increase in the odds of three‐vessel CAD (OR = 1.91, 95% CI = 1.04–3.51, p = 0.037). Although elevated PLR was observed in three‐vessel CAD cases, its association was not statistically significant after adjusting for confounders (OR = 1.79, 95% CI = 0.93–3.41, p = 0.077). The models demonstrated good overall performance, with an area under the curve of 85%. Conclusion NLR is a significant predictor of severe CAD and may serve as a cost‐effective inflammatory biomarker for risk stratification. PLR, while associated with CAD severity, may warrant further investigation. Future studies should explore additional inflammatory markers to enhance CAD risk assessment.