Introduction: Ischemia and nonobstructive coronary arteries (INOCA) remains a significant clinical issue. Recent guidelines underscore the importance of comprehensive coronary physiology assessment to make specific diagnoses and implement tailored treatment strategies.
Objectives: Our primary objective was to implement comprehensive invasive diagnostics. The secondary objective was to determine the pathomechanism of INOCA in consecutive adult patients with symptomatic chronic coronary syndrome, noninvasive evidence of myocardial ischemia, and nonobstructive coronary artery disease included in the prospective MOSAIC‑COR registry, and therefore, to define new INOCA subgroups.
Patients and methods: All patients underwent comprehensive coronary physiological assessment, including resting full‑cycle ratio, fractional flow reserve, index of microcirculatory resistance, and coronary flow reserve using a pressure wire and the thermodilution method. Coronary artery reactivity was assessed with acetylcholine in a provocative test.
Results: A total of 173 patients were enrolled (median [interquartile range] age, 66 [58-71] years; 66% women). A high prevalence of typical cardiovascular risk factors was registered. According to physiological assessment, the patients were divided into the following subgroups: epicardial vasospastic angina (EVSA; 19%), microvascular vasospastic angina (MVSA; 19%), coronary microcirculatory disease (CMD; 11%), EVSA+CMD (21%), MVSA+CMD (18%), and noncoronary disorders (12%). The diagnosis of MVSA and MVSA+CMD was more frequent in women (94% vs 76%, respectively).
Conclusions: The patients diagnosed with INOCA in the MOSAIC‑COR registry exhibit significant symptomatology and a high prevalence of typical cardiovascular risk factors. Myocardial ischemia in this population may be generated by various pathomechanisms that may overlap.