Lesion Morphological Characteristics and Prognosis of Non-ST-Elevation Myocardial Infarction Patients With Different Types of Culprit Artery.

BACKGROUND: Occlusion of the culprit artery (OCA) is observed in a substantial proportion of non-ST-segment elevation myocardial infarction (NSTEMI) patients, showing a poor clinical prognosis. NSTEMI management remains challenging, potentially due to pathophysiological mechanisms across different clinical phenotypes. This study investigated the morphological features of culprit plaque in NSTEMI with vs. without OCA. METHODS AND RESULTS: In all, 324 NSTEMI patients who underwent optical coherence tomography (OCT) imaging were enrolled in this study. Patients were divided into an OCA group (n=105; 32.4%) and a non-OCA group (n=219; 67.6%). Compared with the non-OCA group, the OCA group had significantly higher rates of plaque rupture (67.6% vs. 42.5%; P<0.001), lipid-rich plaque (81.0% vs. 67.1%; P=0.01), thin-cap fibroatheroma (48.6% vs. 25.1%; P<0.001), thrombus (88.6% vs. 66.7%; P<0.001), macrophage accumulation (92.4% vs. 76.7%; P<0.001), and cholesterol crystals (48.6% vs. 27.4%; P<0.001) on OCT. Symptom-to-catheter time was found to be an independent predictor of 2-year major adverse cardiovascular events for OCA patients. CONCLUSIONS: The underlying plaque morphologies were different between OCA and non-OCA patients. The OCA had a higher rate of plaque rupture, with more features (e.g., lipid-rich plaque, thin-cap fibroatheroma, thrombus, macrophage accumulation, cholesterol crystals) resembling ST-elevation myocardial infarction-like plaques. Symptom-to-catheter time was an independent predictor of major adverse cardiovascular events in the OCA group.