ST-segment elevation myocardial infarction (STEMI) remains a major cause of morbidity and mortality, with survivors facing high risk of heart failure, recurrent ischemia, and arrhythmias. Risk stratification traditionally relies on echocardiography, while cardiac magnetic resonance (CMR) is the most effective tool for predicting adverse outcomes. However, its routine use is limited by accessibility, cost, and logistical constraints. Recently, cardiac computed tomography (CCT) has evolved from an angiographic tool to a comprehensive imaging modality capable of assessing wall motion abnormalities and myocadial tissue characteristics.The CT-STEMI study aims to (1) evaluate the diagnostic accuracy of CCT for myocardial morphofunctional assessment and tissue characterization compared to CMR, (2) determine the prognostic value of CCT-derived features for adverse outcomes, and (3) assess the role of CCT in quantifying atherosclerotic burden in STEMI patients.CT-STEMI (NCT06020209) is a prospective, multicenter observational study enrolling STEMI patients treated with primary PCI within 24 ​h of symptom onset. Each patient undergoes comprehensive CCT (pre-contrast imaging, full R-R interval angiography, and late iodine enhancement) and CMR within 10 days of the acute event, with imaging sequence randomized. Patients will be followed longitudinally for heart failure, arrhythmic events, and recurrent ischemic complications.This study aims to validate CCT as a cost-effective, comprehensive imaging modality for post-STEMI risk stratification, with the added benefit of coronary artery evaluation. If successful, CCT could serve as an efficient, one-stop diagnostic tool, enhancing patient outcomes while optimizing healthcare resources.