Association between lactate/albumin ratio and mortality in patients with heart failure after myocardial infarction

Abstract

Aims: Lactate/albumin ratio (L/A) is a recognized prognostic index of patients with heart failure (HF) after myocardial infarction (MI). We aim to evaluate the prognostic value of L/A ratio in predicting in-hospital mortality for those patients.

Methods and results: We enrolled qualified patients from Medical Information Mart for Intensive Care IV database for retrospective study. A receiver operating characteristic (ROC) curve of the subjects was applied to determine the predicted value and the best cut-off value of L/A on admission. Univariate/multivariate Cox regression analysis and restricted cubic splines (RCS) were performed to identify the association between hospital admission and hospital mortality. The Kaplan-Meier (KM) method was used to draw the survival curve of the two groups with different L/A levels at admission. L/A values at admission were significantly higher in the death groups than the survival groups [1.36 (1.20) vs. 0.62 (0.36), P < 0.05], and area under the ROC curve [0.780 (95% confidence interval, 0.772-0.827)] was better than other indicators, and the best the cut-off value was 0.671. Data of Cox regression analysis showed that higher L/A value supposed to be an independent risk factor for in-hospital mortality. RCS analysis showed evidence of an increasing trend and a non-linear relationship between L/A and in-hospital mortality (P value was non-linear <0.05). KM survival curves were significantly lower in the high L/A group than the low L/A group (P < 0.001), and the former group had an increased risk of in-hospital mortality compared with the latter one (log rank P < 0.001).

Conclusions: Elevated L/A ratio on admission is an independent predictor of high in-hospital mortality in post-MI heart failure patients, which proved to be better than lactate, Sequential Organ Failure Assessment score and other related indicators.

Keywords: Heart failure (HF); Lactate/albumin ratio (L/a); MIMIC-IV; Mortality; Myocardial infarction (MI); Prognostic indicator.