The association between anion gap and prognosis in patients myocardial infarction with congestive heart failure: a retrospective analysis of the MIMIC-IV database.

Background: Elevated serum anion gap at hospital admission is often linked to a poor prognosis in critically ill patients, but there is insufficient data on this correlation in patients with acute myocardial infarction accompanied by heart failure. In this study, we aimed to determine the relationship between serum admission AG and all-cause mortality in patients with acute myocardial infarction accompanied by heart failure.

Methods: We conducted a retrospective analysis of data within the MIMIC-IV database. Serum AG was collected at ICU admission, and all-cause mortality after discharge was analyzed. Multivariable Cox proportional hazards regression models and Kaplan-Meier survival curve analyses were used to assess the relationship between serum AG and myocardial infarction accompanied by heart failure as well as all-cause mortality.

Results: A total of 943 patients with acute myocardial infarction complicated by heart failure were included in the study. The all-cause mortality rate after discharge was 24.7% and 18.9%. Multivariable analysis, adjusted for potential confounders, indicated that compared to low serum AG levels (< 12 mmol/L), high serum AG levels (> 17 mmol/L) were associated with an increased risk of all-cause mortality. Similarly, Kaplan-Meier survival curves also indicated that patients with higher serum AG levels had lower survival rates. Stratified analysis further showed that the association between higher serum AG levels and in-hospital all-cause mortality was observed across different subgroups based on stratification variables.

Conclusions: In patients with acute myocardial infarction complicated by heart failure, elevated serum AG levels at ICU admission are associated with an increased risk of all-cause mortality.