Red blood cell distribution width-to-albumin ratio and in-hospital major adverse cardiovascular events in patients with acute myocardial infarction complicated by cardiogenic shock: a two-center retrospective cohort study.

OBJECTIVE: To investigate the relationship between red blood cell distribution width-to-albumin ratio (RAR) and major adverse cardiovascular events (MACE) in patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS) during hospitalization. METHODS: This retrospective cohort study enrolled patients from Xuzhou Central Hospital and the First People's Hospital of Yancheng between January 2019 and December 2024. Patients were stratified into four quartiles according to admission RAR. The relationship between RAR and in-hospital MACE (all-cause death, recurrent non-fatal myocardial infarction, unplanned revascularization, non-fatal stroke) was assessed using multivariate logistic regression, Kaplan-Meier curves, and receiver operating characteristic (ROC) analysis. RESULTS: A total of 3,316 AMI patients were screened and 264 AMI-CS patients were enrolled in this study. Mortality rates across RAR quartiles (lowest to highest) were 33.3%, 37.9%, 54.5%, and 66.7%, and MACE rates were 54.5%, 53.0%, 62.1%, and 78.8% (P < 0.001). After adjustment for confounders, elevated RAR was an independent predictor of in-hospital MACE (odds ratio [OR] = 2.063, 95% confidence interval [CI]: 1.374-3.009, P < 0.001) and mortality (OR = 2.033, 95% CI: 1.341-3.084, P = 0.001). The highest RAR quartile was associated with a 4.008-fold higher risk of MACE (95% CI: 1.504-10.680, P = 0.006) and a 3.354-fold higher risk of mortality (95% CI: 1.414-7.958, P = 0.006) compared with the lowest quartile. Kaplan-Meier curves showed that higher RAR quartiles were associated with higher rates of MACE and mortality (P < 0.001). RAR exhibited better predictive performance than RDW or albumin alone, with an area under the curve (AUC) of 0.734 (cutoff = 4.335) for MACE and 0.716 (cutoff = 4.400) for mortality. CONCLUSION: RAR showed higher discriminatory performance than RDW or albumin alone in AMI-CS patients and may be considered a candidate prognostic marker requiring further validation.Clinical Trial Registration: https://www.clinicaltrials.gov, identifier NCT07507110.