Peripheral blood neutrophil-to-lymphocyte ratio is associated with mortality across the spectrum of cardiogenic shock severity

Abstract

Purpose: To evaluate the association between the neutrophil-to-lymphocyte ratio (NLR) and mortality across the cardiogenic shock (CS) severity spectrum, defined using the Society of Cardiovascular Interventions and Angiography (SCAI) shock stages.

Materials and methods: We retrospectively analyzed cardiac intensive care unit (CICU) patients between 2007 and 2015. Predictors of in-hospital mortality were analyzed using logistic regression.

Results: We included 8280 patients aged 67.3 ± 15.2 years (37.2% females). Elevated NLR (≥7) was present in 45% of patients. NLR increased with worsening SCAI stage and was associated with higher in-hospital mortality in shock stages A to C (all p < 0.001). After multivariable adjustment, NLR remained associated with higher in-hospital mortality (adjusted odds ratio 1.05 per 3.5 NLR units, 95% CI 1.03-1.08, p < 0.001), with an optimal cut-off of ≥7 (in-hospital mortality 13.1% vs. 4.1%, adjusted odds ratio 1.44, 95% CI 1.14-1.81, p = 0.002). Patients in SCAI stage A or B with NLR ≥7 had higher in-hospital mortality than patients in SCAI stage B or C with NLR <7, respectively.

Conclusions: Elevated NLR is associated with higher in-hospital mortality in CICU patients with or at risk for CS, emphasizing the importance of systemic inflammation as a determinant of outcomes in CS patients.

Keywords: Cardiac critical illness; Cardiac intensive care unit; Cardiogenic shock; Inflammation; Severity of illness; Shock.