Lactate-to-albumin ratio and 28 day mortality in hypertensive patients with atrial fibrillation: a retrospective cohort study.

Background: The lactate-to-albumin ratio (LAR) has emerged as a composite biomarker reflecting metabolic stress and nutritional status. This study aimed to evaluate the association between the LAR and 28 day mortality in hypertensive patients with atrial fibrillation (AF).

Methods: We conducted a retrospective cohort study using the MIMIC-IV v3.1 database. Patients were screened for inclusion based on predefined criteria, resulting in a final cohort of 1087 eligible patients. Mortality within 28 days of ICU admission was the primary endpoint. Statistical analyses included LASSO regression and multivariate Cox regression, receiver operating characteristic (ROC) curve, and Kaplan‒Meier survival curve analyses.

Results: The overall 28 day mortality rate was 22.8% (n = 248). Compared with survivors, nonsurvivors presented significantly higher LAR values (0.74 vs. 0.52, p < 0.001). Multivariate analyses indicated that the LAR was an independent predictor of 28-day mortality (HR 1.03, 95% CI 1.01-1.06, p < 0.05), even after adjusting for multiple clinical confounders. ROC analysis confirmed that the LAR had superior predictive ability (AUC 0.661) compared with other biomarkers. Kaplan‒Meier survival analysis revealed significant differences in mortality between the high- and low-LAR groups (HR 2.55, 95% CI 1.97-3.30, p < 0.05).

Conclusions: The LAR is an independent predictor of short-term mortality in hypertensive patients with AF. As a practical and easily applicable biomarker, the LAR holds significant potential for early risk stratification and tailored management in this high-risk population. Our findings underscore the importance of integrating LAR into clinical practice to optimize patient outcomes in critical care settings.