Abstract
BACKGROUND: The monocyte-to-lymphocyte ratio (MLR) has emerged as a novel marker of inflammation. Nevertheless, its potential utility in predicting the development of left ventricular aneurysm (LVA) remains unexplored. This study aims to investigate the association between MLR and the risk of LVA in patients presenting with acute ST segment elevation myocardial infarction (STEMI). METHODS: A total of 551 patients were enrolled in the first cohort, and 471 patients were included in the validation cohort. To evaluate the predictive value of MLR for LVA, multivariable logistic regression analysis, restricted cubic splines (RCS) analysis, and receiver operating characteristic (ROC) analysis were employed. RESULTS: The prevalence of LVA was 14.5% in the first cohort and 13.6% in the validation cohort. The multivariable logistic regression analysis revealed that individuals in the highest quartile of MLR (Q4) exhibited a significantly increased risk of LVA formation compared to those in the lowest quartile (Q1) in both cohorts (first cohort: OR = 3.07, 95% CI = 1.33-7.08, P = 0.009; validation cohort: OR = 3.55, 95% CI = 1.34-9.42, P = 0.011). The RCS analysis identified a positively nonlinear association in the first cohort and a positively linear association in the validation cohort between MLR and the risk of LVA (overall P < 0.05). Furthermore, the discriminative ability of MLR for LVA is 0.69 in the first cohort and 0.71 in the validation cohort, exceeding that of both monocyte and lymphocyte alone. The subgroup analyses further substantiated the robustness of our findings. CONCLUSION: An elevated MLR was independently linked to an increased risk of LVA development in patients with STEMI who received primary PCI. This readily available inflammatory index may offer supplementary prognostic information and could be considered for inclusion in future risk stratification models.