Pre-procedural neutrophil-to-lymphocyte ratio and long-term cardiac outcomes after percutaneous coronary intervention for stable coronary artery disease

Abstract

Background and aims: An elevated neutrophil-to-lymphocyte ratio (NLR) has been associated with worse clinical outcomes in patients with acute coronary syndrome. However, the long-term prognostic value of NLR in stable coronary artery disease (CAD) after percutaneous coronary intervention (PCI) has not been fully investigated. The aim of this study was to determine whether NLR is an independent predictor of long-term cardiac outcomes after PCI.

Methods: A total of 2070 patients with CAD who underwent elective PCI were enrolled in the study. Patients were divided into three groups by NLR tertile (<1.7, 1.7-2.5, and 2.5<). Incidences of all-cause death and cardiac death were evaluated.

Results: During follow-up (median, 7.4 years), 300 patients (14.5%) died. Kaplan-Meier curves revealed ongoing divergence in rates of all-cause death and cardiac death among tertiles (both log-rank p < 0.01). In multivariate analysis, using the lowest tertile as reference, the highest tertile remained significantly associated with greater incidences of all-cause death (hazard ratio (HR), 1.73; 95% confidence interval (CI), 1.29-2.34; p = 0.0002). Continuous NLR values were also an independent predictor of all-cause death (HR, 1.87 per log NLR 1 increase; 95% CI, 1.50-2.32; p < 0.0001) and cardiac death (HR, 2.11; 95% CI, 1.46-3.05; p < 0.0001). Adding NLR values to a baseline model with established risk factors improved the C-index (p = 0.002), net reclassification improvement (p = 0.008) and integrated discrimination improvement (p = 0.0001) for all-cause death.

Conclusions: Elevated NLR was an independent predictor of long-term cardiovascular outcomes after elective PCI. Assessing pre-PCI NLR may be useful for risk stratification of stable CAD.

Keywords: Atherosclerosis; Coronary artery disease; Inflammation.