Association between short-term changes in serum magnesium and in-hospital mortality following acute myocardial infarction: a cohort study based on the MIMIC database.

Background: The association between short-term changes in serum magnesium level and risk of in-hospital mortality was investigated in patients with acute myocardial infarction (AMI). Methods: In this retrospective cohort study, data of 2,716 patients with AMI were extracted from the Medical Information Mart for Intensive Care (MIMIC-III and MIMIC-IV) database for 2001-2012. Univariate and multivariate Cox proportional hazards models were used to explore the association between serum magnesium level and short-term change and in-hospital mortality in patients with AMI. In addition, subgroups according to age, gender, Sequential Organ Failure Assessment (SOFA) score, and Simplified Acute Physiology Score (SAPS-II) were also analysed. Results: In total, 504 (18.6%) patients died in hospital. After adjusting for covariates, all AMI patients with high magnesium levels at ICU admission (HR=1.03, 95% CI: 0.83-1.27) or 48 hours after ICU admission (all p <0.05), or those demonstrating a change in magnesium level within the first 48 hours of ICU stay (all p <0.05) were shown to have a high risk of in-hospital mortality. Moreover, this correlation was retained irrespective of age, gender, SOFA score, and SAPS-II (all p <0.05). Conclusion: Serum magnesium levels at different time points after ICU admission and change in serum magnesium level during the first 48 hours were associated with in-hospital mortality in patients with AMI, indicating that clinical attention should be paid to short-term changes in serum magnesium levels regarding treatment adjustment, which may further reduce the risk of mortality. [ABSTRACT FROM AUTHOR]