This research examines the role of systematic cardiac troponin evaluation in identifying type 1 myocardial infarction among patients presenting to the emergency department with collected blood samples. This was a prospective study of consecutive adult patients presenting to the emergency department of a university hospital between October 22, 2020, and January 11, 2021. Cardiac troponin I levels were measured in all patients, including those with suspected acute coronary syndrome (clinical testing) and a control group undergoing routine blood tests (non-clinical testing). The primary outcomes were the prevalence of type 1 myocardial infarction and the positive predictive value of cardiac troponin I, which were assessed using established statistical methods. Elevated cardiac troponin levels were identified in 13.4% of the study population (382/2,853). This included 19.5% of patients with clinically guided tests and 10.1% of those with non-clinical testing. The overall prevalence of type 1 myocardial infarction was 2%, with a positive predictive value of 14.9% (95% CI: 13.6–16.2). Among clinically guided tests, type 1 myocardial infarction prevalence was 5.8%, yielding a positive predictive value of 29.5% (95% CI: 26.7–32.4). Cases from non-clinically guided tests were primarily attributed to type 2 myocardial infarction or non-ischemic myocardial injury. Using a generalized approach to cardiac troponin testing in emergency department patients significantly lowers the diagnostic accuracy for type 1 myocardial infarction, reducing the positive predictive value and frequently indicating non-ischemic myocardial injury.

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.