Association of lymphocyte-to-monocyte ratio with the long-term outcome after hospital discharge in patients with ST-elevation myocardial infarction: a retrospective cohort study

Lymphocyte-to-monocyte ratio (LMR), a novel systemic inflammatory factor, correlates with adverse outcomes in patients with cardiovascular disease. However, data are limited regarding the prognostic value of LMR in patients with ST-elevation myocardial infarction (STEMI) after hospital discharge. Therefore, the aim of our study was to evaluate the prognostic impact of admission LMR in hospital survivors of STEMI. This retrospective observational study enrolled 1369 STEMI patients between 2014 and 2017. The study population was divided into three groups according to tertiles (T) of LMR (T1: ≥2.84; T2: 1.85-2.83; T3: <1.85). The primary outcomes were long-term outcomes after discharge including major adverse cardiac events (MACE) and all-cause mortality. The associations between LMR and long-term outcomes were assessed using Cox regression analysis. The median follow-up period was 556 days (interquartile range, 342-864 days). Independent correlations were observed between LMR and both long-term MACE and all-cause mortality. For long-term MACE, the T3 (adjusted hazard ratio [HR], 1.74; 95% confidence interval [CI]: 1.12-2.70; P = 0.013) and T2 groups (adjusted HR, 1.65; CI: 1.07-2.54; P = 0.024) showed significantly higher risk of MACE than did the T1 group. For long-term all-cause mortality, the adjusted HR was 3.07 (CI: 1.10-8.54; P = 0.032) in the T3 group and 2.35 (CI: 0.82-6.76; P = 0.112) in the T2 group compared with that of the T1 group. Decreased admission LMR was independently associated with long-term all-cause mortality and MACE after discharge in patients with STEMI.