Myocardial infarction with non-obstructive coronary arteries: A multimodal imaging approach to diagnosis and...

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a clinically heterogeneous working diagnosis accounting for 5-15% of acute myocardial infarction presentations. Its differential diagnosis spans multiple ischemic coronary mechanisms as well as important non-ischemic mimickers that must be systematically excluded. Despite its prevalence and significant associated risk of major adverse cardiovascular events, patients are frequently discharged without a definitive diagnosis or a targeted management plan, reflecting therapeutic inertia driven by pathophysiological complexity. Intracoronary optical coherence tomography and intravascular ultrasound identify culprit coronary mechanisms, including plaque disruption, spontaneous coronary artery dissection, and thrombus, in a substantial proportion of cases invisible to conventional angiography. Invasive functional coronary angiography with provocative vasomotor testing identifies epicardial and microvascular spasm as primary mechanisms in over half of patients tested. Cardiac magnetic resonance imaging serves as the non-invasive gold standard for myocardial tissue characterization, confirming ischemic injury, reclassifying non-ischemic mimics such as myocarditis and Takotsubo syndrome, and providing independent prognostic information. Combining these modalities identifies a specific etiology in the majority of cases and directly informs mechanism-based therapy, from antiplatelet and lipid-lowering agents for plaque disruption, to calcium channel blockers for vasospasm, to conservative management for spontaneous dissection. The recently published PROMISE trial provides the first prospective, randomized evidence that a stratified, imaging-guided approach improves patient-centered outcomes compared with standard care. This review synthesizes current evidence on the diagnostic and therapeutic framework for MINOCA, aiming to guide clinicians toward a systematic, etiology-targeted, and individualized management strategy.