Lymphocyte-to-Monocyte Ratio as a Prognostic Biomarker for Acute Myocardial Infarction: A Systematic Review and Meta-Analysis

Background: The prognostic value of lymphocyte-to-monocyte ratio (LMR) for acute myocardial infarction (AMI) has been underscored by multiple studies. Therefore, we initiated this meta-analysis to examine the correlation between LMR and prognostic outcomes in patients with AMI. Methods: A comprehensive literature search was conducted across multiple databases, including Embase, PubMed, Web of Science, and the Cochrane Library, covering the period from the inception of the databases to October 24, 2024, focusing on studies comparing mortality and/or incidence of major adverse cardiovascular events (MACEs) by the pooled odds ratios (ORs) and respective 95% confidence intervals (CIs) between different LMR levels in AMI patients. Results: Our meta-analysis encompasses 11 studies and involves a total of 7719 patients. The results indicate that individuals in the lower LMR group exhibit notably elevated mortality rates (OR = 2.43, 95% CI: 1.46-4.04, and p = 0.0006) and increased incidence of MACE (OR = 1.57, 95% CI: 1.27-1.95, and p = 0.0001) compared with those with high LMR. Subgroup analysis further reveals that lower LMR correlated with higher mortality and MACE in the context of confounding factors such as the sample size and cutoff value. Conclusion: Our meta-analysis confirms the prognostic value of LMR in AMI patients. Lower LMR levels correlate with elevated mortality and increased incidence of MACE. This implies the clinical potential of LMR as an effective prognostic biomarker aiding in better risk assessment, personalized treatment strategies, and improved clinical outcomes.