Background: Left ventricular aneurysm (LVA) is a major mechanical complication following acute ST-segment elevation myocardial infarction (STEMI). This study aimed to evaluate the predictive ability of the lactate dehydrogenase to albumin ratio (LAR) for the risk of LVA among STEMI patients. Methods: The study was conducted from July 2018 to 2025 across three medical centers in China. The study cohort comprised STEMI patients who underwent primary percutaneous coronary intervention across three medical centers. Multivariate logistic regression analysis and Restricted cubic spline plots were employed to assess the association between different LAR levels and LVA risk. Subgroup analyses were conducted to assess the consistency of the result. Results: The study included 551, 471, and 1384 eligible participants from the first, second, and third cohort, respectively. After adjusting for potential confounders, individuals in the highest quartile of LAR (Q4) demonstrated a significantly elevated risk of developing LVA compared to those in the lowest quartile (Q1) across all cohorts (First cohort: OR = 3.63, 95% CI = 1.65 - 7.96, P = 0.001; Second cohort: OR = 6.01, 95% CI = 2.22 - 16.26, P< 0.001; Third cohort: OR = 2.41, 95% CI = 1.47 - 3.96, P< 0.001). RCS analysis revealed a positive linear association between LAR and the risk of LVA across the three cohorts (overall P> 0.05). The predictive capacity of LAR for assessing LVA risk exceeded that of both lactate dehydrogenase and albumin (P< 0.05). Subgroup analyses further reinforced the robustness of these findings. Conclusion: An elevated LAR was independently associated with an increased risk of LVA development in patients with STEMI who underwent primary PCI.

The C-reactive protein (CRP) to albumin ratio (CAR) has emerged as a novel marker of inflammation. However, its potential predictive value for the development of left ventricular aneurysm (LVA) has not yet been evaluated. This study aims to explore the association between CAR and the risk of LVA in patients experiencing acute ST-segment elevation myocardial infarction (STEMI). This study recruited 551 patients in the first cohort and 471 patients in the validation cohort. Multivariable logistic regression analysis, restricted cubic splines (RCS) analysis, and receiver operating characteristic were conducted to assess the predictive value of CAR for LVA. The prevalence of LVA were 14.5% in the first cohort and 13.6% in the validation cohort. Multivariable logistic regression analysis indicated that individuals in the highest quartile of CAR (Q4) were significantly associated with the risk of LVA formation compared to those in the lowest quartile (Q1) in both cohorts (First cohort: OR = 3.26, 95% CI = 1.51–7.05, P = 0.003; Validation cohort: OR = 4.05, 95% CI = 1.71–9.60, P = 0.002). RCS analysis demonstrated a positive and nonlinear association between CAR and the risk of LVA (overall P < 0.05, nonlinear P < 0.05). Furthermore, the discriminative ability of CAR for LVA is 0.72 in the first cohort and 0.74 in the validation cohort, exceeding that of both CRP and albumin alone. Subgroup analyses further corroborated the robustness of our findings. Elevated CAR was independently linked to an increased risk of LVA development in patients with STEMI who received primary PCI. This finding may hold considerable significance for clinical practice and could aid in the development of a personalized prevention strategy that incorporates the monitoring of CAR.