Coronary Morphological Features in Women With Non-ST-Segment Elevation MINOCA and MI-CAD as Assessed by OCT

Abstract AIMS We aimed to use optical coherence tomography (OCT) to identify differences in atherosclerotic culprit lesion morphology in women with myocardial infarction with non-obstructive coronary arteries (MINOCA) compared with MI with obstructive coronary artery disease (MI-CAD). METHODS AND RESULTS Women with an OCT-determined atherosclerotic etiology of non-ST segment elevation (NSTE)-MINOCA (angiographic diameter stenosis <50%) who were enrolled in the multicenter Women’s Heart Attack Research Program (HARP) study were compared to a consecutive series of women with NSTE-MI-CAD who underwent OCT prior to coronary intervention at a single institution. Atherosclerotic pathologies identified by OCT included plaque rupture, plaque erosion, intraplaque hemorrhage (IPH, a region of low signal intensity with minimum attenuation adjacent to a lipidic plaque without fibrous cap disruption), layered plaque (superficial layer with clear demarcation from the underlying plaque indicating early thrombus healing), or eruptive calcified nodule. We analyzed 58 women with NSTE-MINOCA and 52 women with NSTE-MI-CAD. OCT features of underlying vulnerable plaque (thin-cap fibroatheroma) were less common in MINOCA (3% vs 35%) than in MI-CAD. IPH (47% vs 2%) and layered plaque (31% vs 12%) were more common in MINOCA than MI-CAD, whereas plaque rupture (14% vs 67%), plaque erosion (8% vs 14%), and calcified nodule (0% vs 6%) were less common in MINOCA. The angle of ruptured cavity was smaller and thrombus burden was lower in MINOCA. CONCLUSION The prevalence of atherothrombotic culprit lesion subtype varied substantially between MINOCA and MI-CAD. A majority of culprit lesions in MINOCA had the appearance of IPH or layered plaque.