Coronary microvascular dysfunction and myocardial infarction with non-obstructive coronary arteries: Where do we stand?

• Myocardial infarction with non-obstructive coronary arteries (MINOCA) constitutes a significant proportion of patients who are at excess cardiovascular risk and have adverse clinical outcomes. • Coronary microvascular dysfunction (CMD) plays a potential role in the pathogenesis of MINOCA and may affect clinical outcomes, however, the role of functional and structural mechanisms of CMD in MINOCA remains unknown. • CMD can be assessed by various invasive and non-invasive tools depending on availability and clinical settings. • A better understanding of CMD in MINOCA has significant clinical implications for decision-making, identifying novel therapies that target CMD and improve clinical outcomes. In the past decade, scientific and clinical research has provided a translational perspective on myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA). MINOCA is characterized by clinical documentation of an acute MI but angiography shows no significant coronary artery obstruction (stenosis <50%). The prevalence of MINOCA is estimated to range from approximately 6 to 10% among MI patients, and those with this condition have a poor prognosis, experiencing high rates of mortality, rehospitalization, and socioeconomic burden. MINOCA represents a major unmet need in cardiovascular medicine, with uncertain clinical management. It is a complex condition that can be caused by various factors, including atherosclerosis, plaque rupture, coronary vasospasm, and microvascular dysfunction. Effective management of MINOCA depends on identifying the underlying mechanism of the infarction, thus a systematic diagnostic approach is recommended. Contemporary data shows that a significant number of patients exhibit structural and functional abnormalities in coronary microcirculation, which is referred to as coronary microvascular dysfunction (CMD). CMD plays a crucial role in patients with signs and symptoms of myocardial ischemia and non-obstructive coronary artery stenosis, including MINOCA. Furthermore, conducting a thorough evaluation of coronary function can have significant prognostic and therapeutic implications, since personalized patient management strategies based on this assessment have been shown to improve symptoms and prognosis. Therefore, an accurate and timely diagnosis of CMD is essential for effective patient management, which can be achieved through various invasive and non-invasive methods. This review will discuss the pathophysiological understanding, current diagnostic techniques, and management strategies of patients with MINOCA and CMD. [Display omitted] [ABSTRACT FROM AUTHOR]