Association of lymphocyte to monocyte ratio and risk of in-hospital mortality in patients with cardiogenic shock: A propensity score matching study

Abstract

Background: Lymphocyte to monocyte ratio (LMR) has been long implicated in the prediction of many inflammatory-related diseases. However, the possible value as prognostic marker of LMR have not been evaluated in cardiogenic shock (CS) patients. The aim of the study was to assess the relationship between LMR on admission and in-hospital mortality in CS patients. Methods: Data on patients diagnosed with CS were extracted from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database. We performed a single-institution, retrospective study of 1487 CS patients and determined the optimal cut-off for LMR by X-tile software. Propensity score matching (PSM) and inverse probabilities of treatment weighting (IPTW) were conducted to control confounders. Cox proportional hazards model was performed to evaluate the relationship between LMR and in-hospital mortality. Kaplan– Meier curves and receiver operating characteristics (ROC) analysis were applied to assess the prognostic value of LMR. Results: The optimal cut-off value for LMR was 0.9. Cox proportional hazards model demonstrated that lower LMR (< 0.9) was independently associated with in-hospital mortality with hazard ratio (HR) of 1.40 (1.12–1.74, P = 0.003). The results were consistent with survival analyses (P < 0.001, Log rank test). Adding LMR< 0.9 to the sequential organ failure assessment (SOFA) score improved discrimination and risk stratification for in-hospital mortality. Conclusion: Lower level of LMR is related to higher risk of in-hospital mortality of patients with CS. As an easily available biomarker, LMR can independently predict the in-hospital mortality in CS patients.