Feasibility and Impact of Invasive Coronary Function Testing in Ischemia and No Obstructive Coronary Arteries: A Single-Center Study

Background:In patients with suspected ischemia and no obstructive coronary arteries (INOCA), coronary function testing (CFT) helps identify underlying endotypes.Despite guideline support, adoption of CFT remains limited.This study assessed the feasibility of CFT and its impact on medical management.Methods: This single-center, prospective study (2020-2025) evaluated CFT implementation and subsequent medication changes in patients with clinically indicated CFT.Interventional cardiologists completed postprocedure surveys rating CFT feasibility, preparation, lab support, and diagnostic value.CFT results were categorized into coronary microvascular disease (CMD), (coronary flow reserve 75% epicardial constriction), or (2) microvascular VA (<75% epicardial constriction); mixed disease (MD) (CMD and VA), and no vasomotor diagnosis (no CMD or VA).Medication use was compared at baseline and 30 days after CFT.Results: Five of the 10 interventional cardiologists completed 71 surveys.Overall, 98% rated preparation, training, procedural ease, and diagnostic value as "above average" and would recommend CFT to peers.Mean procedural time was 19 minutes, 7 seconds.There were 10 (14%) adverse events, of which 90% were self-limited.Among 71 patients, 60.6% had CMD, 26.8% VA, and 22.5% MD.CMD patients showed increased angiotensin converting enzyme inhibitor/angiotensin receptor blocker use (39.5% to 55.8%, P = .008)and statin use (53.5% to 65.1%, P = .02).VA patients had increased calcium channel blocker use (68.4% to 89.5%, P = .10).MD and no vasomotor diagnosis had no significant medication changes.Conclusions: CFT was rated highly for feasibility, safety, and clinical value by the interventional cardiologists.CFT appeared to impact the medication management of INOCA endotypes.