Sex Differences in Myocardial Injury: Clinical Characteristics, Outcomes, and Prognostic Implications

Background: Myocardial injury is a known predictor of adverse outcomes. However, the impact of sex on its presentation, management, and prognosis is not fully understood. The aim of this study was to examine these differences in a tertiary hospital setting. Methods: We conducted a retrospective observational study of consecutive emergency department patients undergoing troponin testing from January 2012 to December 2013. Myocardial injury was classified as type 1 myocardial infarction (T1MI), type 2 myocardial infarction, or non-ischemic myocardial injury (NIMI). Clinical characteristics, management, and short- and long-term outcomes were compared by sex over a median follow-up of four years. Interaction analyses were performed to assess whether the effect of myocardial injury on outcomes differed between men and women. Results: Among 3620 patients, myocardial injury was more prevalent in men (31.4% vs. 25.8%; p < 0.001), with male sex independently associated with myocardial injury (odds ratio 1.32; 95% CI 1.11-1.58; p = 0.002). Risk factor profiles and electrocardiographic findings differed between sexes. NIMI was more common in women, while T1MI predominated in men (p < 0.001). Women with myocardial injury were less frequently hospitalized than men (63.1% vs. 74.3%, p < 0.001). After multivariable adjustment, long-term mortality was slightly higher in men (HR 3.39; 95% CI 2.73-4.21; p < 0.001), whereas women had higher adjusted risks of myocardial infarction (MI) (HR 4.11; 95% CI 2.35-7.17; p < 0.001) and heart failure (HF) (HR 1.78; 95% CI 1.25-2.55; p = 0.002). No significant interaction between sex and myocardial injury was observed for any outcome. Conclusions: Significant sex differences exist in myocardial injury type and prognosis. Women face increased risk of future MI and HF, whereas men have higher mortality risk. The effect of myocardial injury on long-term outcomes appears similar in both sexes.