Association of Neutrophil-to-Lymphocyte Ratio with Severity of Coronary Artery Disease in Patients Undergoing Coronary Angiography

Abstract

Background: Coronary artery disease (CAD) remains the leading cause of global mortality. The neutrophil-to-lymphocyte ratio (NLR), derived from routine blood counts, is a simple inflammatory index. Its correlation with angiographic CAD severity in Indian patients remains underexplored.

Objectives: To evaluate the association of NLR with angiographic severity of CAD; to compare NLR across single-vessel (SVD), double-vessel (DVD), and triple-vessel (TVD) disease groups; and to assess NLR utility in predicting high SYNTAX score.

Methods: 250 consecutive patients undergoing elective coronary angiography were enrolled. NLR was calculated from admission complete blood count (CBC). Vessel involvement and SYNTAX score were recorded. Statistical analyses included one-way ANOVA, Pearson correlation, ROC curve analysis, and binary logistic regression.

Results: Of 242 analysable patients, 55 had no obstructive CAD (control), 75 had SVD, 64 DVD, and 48 TVD. Mean NLR rose significantly: 1.82 ± 0.61 (control), 2.74 ± 0.83 (SVD), 3.91 ± 1.12 (DVD), 4.73 ± 1.38 (TVD) — p < 0.001. NLR correlated strongly with SYNTAX score (r = 0.68, p < 0.001). At NLR ≥ 3.2, sensitivity was 78.4% and specificity 81.2% for high SYNTAX score (≥33). Multivariate analysis confirmed NLR as an independent predictor of TVD (OR 3.42; 95% CI 1.87–6.26; p < 0.001).

Conclusions: NLR correlates significantly with angiographic CAD severity and independently predicts multivessel disease. It may serve as a simple, inexpensive pre-angiographic risk stratification tool.