Diagnostic Advancements in MINOCA: Do They Translate to a Better Clinical Outcome? A Review of the Literature

Myocardial infarction with non-obstructive coronary arteries (MINOCA) accounts for approximately 5-15% of all myocardial infarctions and disproportionately affects women. Once treated as a diagnosis of exclusion, MINOCA is now recognised as a heterogeneous, mechanism-based syndrome encompassing atherosclerotic plaque disruption, epicardial and microvascular vasospasm, microvascular dysfunction, coronary thromboembolism, and spontaneous coronary artery dissection (SCAD). Despite the absence of obstructive disease, it carries substantial morbidity and mortality, underscoring the need for accurate aetiological characterisation and tailored therapy. Our aim is to review the contemporary evidence of the role of advanced imaging modalities-cardiac magnetic resonance imaging (CMR), optical coherence tomography (OCT), intravascular ultrasound (IVUS) and invasive functional testing-in the diagnosis, prognostic stratification, and therapeutic guidance of patients with MINOCA. CMR is the non-invasive reference standard for differentiating true ischaemic MINOCA from non-ischaemic mimics such as myocarditis and Takotsubo syndrome, reclassifying the working diagnosis in up to two-thirds of cases. OCT and IVUS provide intracoronary characterisation of culprit substrates that are invisible via angiography, particularly plaque rupture, erosion, intramural haematoma and SCAD, while acetylcholine and adenosine testing identify endothelium-dependent vasospasm and endothelium-independent microvascular dysfunction respectively. Coronary Computed Tomography Angiography (CCTA) could also play an additional role in the diagnosis of epicardial CAD. Each modality additionally carries independent prognostic value, with abnormal findings consistently linked to higher rates of major adverse cardiovascular events. The recently completed PROMISE trial provided the first randomised evidence that stratified, imaging-guided treatment might have some positive impact on angina status and quality of life compared with empirical standard care. In conclusion, advanced imaging has transformed MINOCA from a diagnosis of exclusion into a mechanism-based syndrome amenable to personalised therapy. Broader integration of these modalities into routine practice, supported by further randomised trials, is needed to optimise outcomes.