A novel multimodal imaging approach for working diagnosis of acute myocardial infarction with non-obstructive coronary arteries: a promising diagnostic strategy

Background: Myocardial infarction with non-obstructive coronary arteries (MINOCA) demands prompt mechanistic clarification. Early integration of coronary CT angiography (CCTA) and cardiovascular magnetic resonance (CMR) can refine diagnosis during the acute phase. Methods: Twenty-one consecutive patients (41 ± 10 years; 71% men) presenting with troponin-positive chest pain and unobstructed coronaries underwent CCTA, delayed iodine-enhanced CT for late iodine enhancement (LIE), and CMR imaging within 14 days, with a mean interval of 5 days [interquartile range (IQR) 2–9] between both imaging modalities. CCTA assessed luminal stenosis and high-risk plaque; LIE mapped iodine retention; CMR evaluated myocardial edema and late gadolinium enhancement (LGE). Clinical, electrocardiographic, and laboratory data were collected. Results: Eight patients were classified as MINOCA and 13 as acute myocarditis. Chest pain was universal; dyspnea and syncope occurred in seven and two patients, respectively. Median peak high-sensitivity troponin-I was 1,569 ng/L (IQR 589–5 771). Biventricular systolic function was preserved (mean LVEF 58%; RVEF 55%). LGE appeared in 16 subjects: subendocardial in every MINOCA case and intramural or subepicardial in eight myocarditis cases. Myocardial edema was present in 15 patients. CCTA showed no atherosclerosis in 16 patients; five displayed non-obstructive lesions (<50% stenosis) with high-risk plaque confined to three MINOCA subjects. LIE confirmed iodine uptake matching the LGE pattern in all MINOCA patients and in six with myocarditis. Conclusions: An acute CCTA-CMR protocol may aid in distinguishing ischemic from non-ischemic myocardial injury in presumed MINOCA and unmasks occult high-risk plaques. This multimodal imaging approach reveals occult high-risk coronary plaques and enhances diagnostic accuracy, thereby supporting mechanism-targeted management strategies in patients presenting with troponin-positive chest pain.