Relationship between admission serum sodium levels and mortality in patients with cardiogenic shock complicated by acute myocardial infarction

Background Serum sodium plays an important role in hospitalized patients, but the impact of serum sodium levels on mortality in cardiogenic shock followed by acute myocardial infarction (AMI-CS) patients has not been evaluated. This study was designed to assess the serum sodium levels on mortality in patients with AMI-CS. Methods We enrolled and completed the follow-up of 312 patients with AMI-CS. The primary endpoint was all-cause mortality. Patients were divided into three groups by tertiles based on admission serum sodium levels. The prognostic value of admission serum sodium levels was evaluated using Kaplan–Meier survival curves and Cox regression, and the linearity assumption for admission serum sodium levels and mortality was evaluated. Subgroup analyses were also performed. Results Compared to individuals exhibiting sodium levels ranging from 138.0 to 141.2 mmol/L, patients with sodium levels > 141.2 mmol/L demonstrated comparable long-term mortality rates but a heightened short-term mortality risk. Additionally, a J-shaped association was observed between admission serum sodium levels and mortality. The subgroup analysis suggested that sex, diabetes, and utilization of mechanical circulatory support exert influenced the association between admission serum sodium levels and mortality in AMI-CS patients. Conclusions Elevated admission serum sodium levels were identified as an independent predictor of mortality, particularly within the initial 30-day, among AMI-CS patients. The findings underscore the crucial clinical significance of effectively managing serum sodium levels in AMI-CS patients. Trial registration ChiCTR2500099275 (2025-3-20).