Neutrophil to lymphocyte ratio and long-term cardiovascular outcomes in coronary artery disease patients with low high-sensitivity C-reactive protein level

Abstract

Although an elevated neutrophil to lymphocyte ratio (NLR) has been associated with the adverse outcomes of coronary artery disease (CAD), less is known about its prognostic value among patients with low high-sensitivity C-reactive protein (hs-CRP) levels. We enrolled 2,591 consecutive patients with stable CAD who underwent elective percutaneous coronary intervention (PCI) and had available data on preprocedural hs-CRP and NLR between 2000 and 2016. Of these patients, 1,951 with low-grade hs-CRP levels (< 2.0 mg/L) were di-vided into quartiles based on the NLR values. The primary endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke after the index PCI. Clinical follow-up data were obtained up to 5 years. The median NLR was 1.9 (interquartile range: 1.5-2.5). During the follow-up, 102 events oc-curred (5.2%), with a cumulative incidence that was significantly higher in the highest NLR group than in the other groups (log-rank, P = 0.02). After adjusting for the other cardiovascular risk factors, the risk for the primary endpoint was significantly higher for the highest than in the lowest NLR group (HR 1.97, 95% CI 1.09-3.54, P = 0.02). Increasing NLR as a continuous variable was associated with the incidence of adverse cardiovascular events (HR 1.85 per log 1 NLR increase, 95% CI 1.19-2.88, P = 0.007). In conclusion, the adverse long-term clinical outcomes of CAD patients with low-grade hs-CRP levels has been independently predicted by increased NLR level. NLR could be useful for risk stratification of CAD patients with increased inflammatory marker levels.