Association between lactate dehydrogenase to Albumin ratio at admission and all cause mortality in ICU patients with acute myocardial infarction: A retrospective analysis from the MIMIC database

Background The relationship between the lactate dehydrogenase to albumin ratio (LAR) and all-cause mortality in patients with acute myocardial infarction is unknown. This study aimed to explore this relationship. Methods The MIMIC-IV database was used in this study. The primary outcome indicator was 30-day all-cause mortality, and the secondary outcome was 180-day all-cause mortality. All patients were categorized into 3 groups based on LAR-level tertiles. The Cox proportional risk regression model and the restricted cubic spline (RCS) were used to assess the relationship between LAR level and outcome. Kaplan-Meier curves were used to compare the cumulative survival rates of the groups. ROC curve analysis was used to assess the clinical predictive value of LAR. In addition, subgroup analyses were performed to examine the impact of other influencing factors on outcomes. Results A total of 1041 AMI patients with a mean age of 70.0 (60.0, 79.0) were included in this study, and their 30- and 180-day mortality rates were 26.5% and 36.5%, respectively. In Cox proportional risk regression analyses fully adjusted for confounders, the level of LAR in patients with AMI was an independent predictor of 30- and 180-day mortality. RCS analyses revealed a nonlinear relationship between LAR and outcome events. In addition, Kaplan-Meier curves (log-rank P < 0.001) suggested that cumulative ICU survival was significantly lower in AMI patients in the high LAR group compared with the low LAR group. LAR (AUC = 0.689) was more effective in predicting 30-day all-cause mortality in AMI patients than LDH alone (AUC = 0.665) or ALB (AUC = 0.646). Subgroup analysis showed a significant correlation between LAR and all-cause mortality in different subgroups. Conclusions LAR levels were significantly associated with all-cause mortality in patients with AMI in the ICU. LAR levels can be a valid indicator for grading and treating patients with AMI in the ICU.