Multidimensional CMR profiling at discharge predicts early heart failure–related events after STEMI

Background Despite successful reperfusion, early heart failure (HF) remains frequent after STEMI. We assessed whether a multidimensional cardiac magnetic resonance (CMR) evaluation at discharge identifies patients at risk for 6-month HF-related events in a real-world cohort. Methods Consecutive STEMI patients undergoing discharge CMR were analyzed. The 6-month composite endpoint included HF hospitalization, HF-related emergency visit, NYHA class ≥ II, or LVEF <50% at follow-up. CMR parameters reflected complementary pathophysiological domains: infarct size (structural injury), global radial strain (mechanical dysfunction), and left atrial biplane ejection fraction (atrial functional reserve). Hierarchical logistic modeling and bootstrap validation were performed. Results Among 115 patients with complete CMR and follow-up data, 21 (18%) experienced the composite HF endpoint at 6 months. In univariable analysis, larger infarct size, lower global radial strain (GRS), and reduced left atrial ejection fraction (LAEF) were all associated with increased HF risk. In the final multivariable model, infarct size remained independently associated with HF events (OR 1.08 per 1% increase; p=0.008), corresponding to an 8% increase in odds per 1% increment. Higher global radial strain was independently protective (OR 0.88 per 1% increase; p=0.023), translating into a 12% reduction in odds per 1% increment. Although left atrial ejection fraction was associated with HF risk in univariable analysis, it did not retain independent significance after adjustment (OR 0.95 per 1% increase; p=0.082), suggesting partial overlap with ventricular injury and mechanical impairment. Hierarchical modeling demonstrated incremental discrimination with the sequential addition of atrial functional reserve and radial mechanics beyond infarct size. The multivariable model showed good explanatory power (Nagelkerke R² = 0.405) and favorable discrimination (AUC 0.862). Conclusions Early post-STEMI HF is not driven by infarct size alone. Structural injury, impaired radial mechanics, and reduced atrial functional reserve represent complementary determinants of early structural–functional HF progression. Patients combining larger infarcts, impaired radial contraction, and reduced atrial functional reserve represent a high-risk phenotype for early heart failure progression after STEMI. Multidimensional discharge CMR may refine post-infarction risk stratification in routine clinical practice.