Abstract
Background
Patients with coronary microvascular dysfunction (CMD) are at increased risk of major adverse cardiovascular events. The index of microcirculatory resistance (IMR) is more specific than coronary flow reserve (CFR) for CMD diagnosis, but the microvascular resistance reserve (MRR) shows potential due to its hemodynamic adjustments. Our study evaluated the diagnostic utility of IMR, MRR, and their combination in CMD diagnosis for patients experiencing angina and non-obstructive coronary arteries (ANOCA).