Intravascular imaging in myocardial infarction and ischemia with nonobstructive coronary arteries

Abstract Myocardial infarction with nonobstructive coronary arteries (MINOCA) and angina or ischemia with nonobstructive coronary arteries (ANOCA/INOCA) are heterogeneous syndromes that cannot be adequately characterized by coronary angiography alone. Optical coherence tomography (OCT) identifies thrombus, plaque disruption, and other superficial coronary abnormalities, whereas intravascular ultrasound (IVUS) better characterizes plaque burden, positive remodeling, intramural hematoma, and myocardial bridging. Their roles differ between acute and chronic presentations. In MINOCA, targeted intracoronary imaging during the index angiogram helps identify an acute epicardial mechanism, whereas early cardiac magnetic resonance characterizes myocardial injury, localizes the affected territory, and excludes nonischemic mimics. In ANOCA/INOCA, coronary function testing remains central to identifying vasospastic and microvascular endotypes. Structural findings such as layered plaque, intraplaque hemorrhage, fibroatheroma, or myocardial bridging vary in their mechanistic significance and should not be assumed to represent the cause of the index event solely on the basis of morphology. Territorial myocardial concordance strengthens their association with the involved coronary territory but does not by itself establish causality. We review the complementary roles of OCT and IVUS, examine differences in diagnostic yield among contemporary MINOCA studies, and propose a framework for interpreting intracoronary imaging findings in MINOCA in the context of myocardial and functional information. This approach aims to improve consistency in the interpretation and reporting of intracoronary imaging findings.