Prognostic Significance of CMD Assessed by IMR in HCM Patients

The index of microcirculatory resistance (IMR) serves as an indicator of coronary microvascular dysfunction (CMD) with significant prognostic value in various clinical conditions. However, its impact on CMD in the hypertrophic cardiomyopathy (HCM), whether assessed invasively or non-invasively, is yet to be investigated. We assessed the prognostic importance of CMD using less invasive coronary angiography-derived IMR (caIMR) in HCM patients with nonobstructive epicardial coronary arteries.Patients with HCM who underwent invasive coronary angiography for suspected myocardial ischemia were included. Microvascular function was assessed using caIMR, and 460 coronary arteries were analyzed. CMD was identified with caIMR\>25U, in line with prior research, and the primary study endpoint was major adverse cardiac events (MACE).