Lee, E

Abstract Background Left ventricular ejection fraction (LVEF) and diastolic dysfunction (DD) are key prognostic factors in patients with ST-segment elevation myocardial infarction (STEMI). AI-enabled ECG (AI-ECG) has been shown to have excellent agreement with transthoracic echocardiography (TTE) assessment and incremental prognostic value to LVEF. Methods We retrospectively analyzed 1,005 adult acute STEMI patients referred for echocardiography (10/2007–01/2025) who had ECGs within seven days before and after the reference echocardiogram. The ECG closest to the TTE date was designated as the pre-STEMI and post-STEMI ECG, respectively. AI-ECG was used to classify diastolic function grades and grades 2 and 3 were considered as DD. Patients were stratified by LVEF (≤50% vs. >50%) at the time of TTE and the association between AI-ECG-determined DD and 10-year mortality was assessed using Cox regression and Kaplan-Meier curves. Results Among 1,005 patients (mean age 66.4 ± 13.4 years, 29.9% females), AI-ECG-determined DD prior to STEMI was present in 47.9% of patients with LVEF ≤50% and 30.3% of those with preserved LVEF (>50%). DD status remained unchanged post-STEMI in 79.3% of cases, while 10.2% showed worsening diastolic function. Regardless of LVEF, AI-ECG-determined DD prior to STEMI was associated with higher mortality risk (LVEF ≤50%: HR 3.03, 95% CI 2.16–4.24, p < 0.001; LVEF >50%: HR 2.32, 95% CI 1.58–3.41, p < 0.001). Post STEMI AI-ECG-determined DD remained a significant predictor of mortality (LVEF ≤50%: HR 2.54, 95% CI 1.82–3.53, p < 0.001; LVEF >50%: HR 2.43, 95% CI 1.66–3.58, p < 0.001). Echocardiographically determined DD also correlated with higher mortality (LVEF ≤50%: HR 4.91, 95% CI 2.95–8.15, p < 0.001; LVEF >50%: HR 2.72, 95% CI 1.68–4.41, p < 0.001). In patients with LVEF ≤50%, AI-ECG-determined DD remained associated with higher mortality even after adjusting for echocardiographically determined DD (pre-STEMI: HR 1.85, 95% CI 1.23–2.80, p < 0.001; post-STEMI: HR 1.90, 95% CI 1.23–2.91, p < 0.001). Conclusion AI-ECG-determined DD is a significant predictor of mortality in STEMI, independent of LVEF. The presence of normal filling pressure may indicate a better clinical outcome in patients with reduced LVEF patients. These findings underscore the clinical utility of AI-ECG in refining risk stratification beyond conventional LVEF assessment.