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

TL;DR

A new imaging method combining CT and MRI helps diagnose heart issues in patients with chest pain and clear arteries.

Contribution

A novel multimodal imaging protocol using CCTA and CMR improves acute diagnosis of MINOCA.

Findings

CCTA-CMR protocol distinguishes ischemic from non-ischemic myocardial injury in MINOCA patients.

Multimodal imaging reveals occult high-risk coronary plaques and enhances diagnostic accuracy.

Late iodine enhancement matches LGE patterns in MINOCA and myocarditis cases.

Abstract

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.

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.

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.

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.

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