Ischemia in Patients With Non-obstructive Disease (INOCA) in Italy INOCA IT Multicenter Registry"

Prospective, interventional, multicentre, non-randomized, single-arm open-label study that aims to enroll 200 consecutive patients with suspected chronic ischemic heart disease in the absence of obstructive coronary artery disease (INOCA) at clinically indicated coronary angiography in 3 Italian centers.

During coronary angiography, these patients will be simultaneously subjected to a functional and coronary physiology study (according to the methods reported below):

• Functional evaluation with fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), Resting Full-Cycle Ratio (RFR) of angiographic stenosis> 50%;

• In the presence of coronary angiographic stenosis <50% or> 50% but in the presence of a negative functional assessment (FFR> 0.80 and iFR / RFR> 0.90), coronary flow reserve (CFR) and index of microvascular resistance (IMR) will be measured. IMR and CFR will be assessed using intra-coronary guidance;

• In the presence of CFR> 2.0 and IMR <25, tests with acetylcholine will also be performed in order to evaluate the possible presence of epicardial (focal or diffuse) or microvascular spasm.