Association of monocyte-lymphocyte ratio with in-hospital mortality in cardiac intensive care unit patients.

BACKGROUND: Inflammatory cell plays a very important part in the occurrence and development of cardiovascular disease. As a combination of lymphocyte and monocyte, monocyte-lymphocyte ratio (MLR) was proved to be related to the severity and prognosis of cardiovascular diseases. Our objective was to explore the association between MLR and in-hospital mortality in cardiac intensive care unit (CICU) patients. METHOD: MLR was obtained by dividing monocyte percentage by lymphocyte percentage. All patients were grouped by MLR quartiles. Primary outcome was in-hospital mortality. Binary logistic regression analysis was performed to determine the independent effect of MLR. RESULT: 5512 CICU patients were included. In-hospital mortality increased as MLR quartiles increased (Quartile 4 vs Quartile 1: 16.3 vs 7.8, P < 0.001). After adjusting for confounding variables, MLR was proved to be independently associated with increased risk of in-hospital mortality (Quartile 4 vs Quartile 1: OR, 95% CI: 1.87, 1.38-2.56, P < 0.001, P for trend < 0.001). Subgroup analysis revealed that patients with low Acute Physiology and Chronic Health Evaluation IV (APACHE IV) or with less comorbidities had higher risk of mortality for MLR. As MLR quartiles increased, length of CICU stay (Quartile 4 vs Quartile 1: 2.8, 1.7-5.4 vs 2.1, 1.2-3.7, P < 0.001) and hospital stay (Quartile 4 vs Quartile 1: 8.3, 4.8-11.1 vs 5.3, 3.1-9.3, P < 0.001) were prolonged. CONCLUSION: MLR was independently correlated with in-hospital mortality in CICU patients.