Prevalence and Characteristics of INOCA in Patients With Either Angiographically Normal Vessels or Non‐Obstructive Coronary Atherosclerosis. Insights From the All‐Comers Prospective AID‐ANGIO Study

BACKGROUND: Myocardial ischemia of non-obstructive origin (INOCA) is a prevalent cause of chronic coronary syndromes (CCS). Risk factors for atherosclerosis have also been described to promote INOCA, raising the question whether these entities are clinically related. AIMS: Our aim was to compare the prevalence and clinical characteristics of INOCA in patients with and without coronary atherosclerosis. METHODS: Sub-analysis of the all-comers, prospective, multicentre AID-ANGIO study, enrolling consecutive CCS patients, referred for coronary angiography. Obstructive coronary artery disease (CAD) was investigated by angiography and pressure guidewires. In the absence of obstructive-CAD, functional coronary testing (FCT) was performed within the same procedure. All patients diagnosed with INOCA were classified according to the evidence of non-obstructive atherosclerosis (INOCA-Ath) or the presence of angiographically normal coronary arteries (INOCA-NoAth). RESULTS: In the AID ANGIO study, 89 patients presented non-obstructive coronary atherosclerosis and 104 had angiographically normal coronary arteries. Prevalence of INOCA-Ath and INOCA-NoAth was 78.7% and 70.2%, respectively (p = 0.181). Patients' symptoms, results from ischemia tests and endotype distribution were comparable in both groups. Vasomotor abnormalities were the most frequently identified (81.4% INOCA-Ath vs. 74.0% INOCA-NoAth; p = 0.285). INOCA endotype was not predicted by the presence of coronary atherosclerosis, typical anginal symptoms, a positive ischemia test or atherogenic risk factors, whereas a youger age was associated with vasomotor disorders. CONCLUSIONS: In an all-comers population of patients with CCS, prevalence of INOCA was similar in patients with and without non-obstructive CAD. Clinical features and endotype distribution were also comparable, highlighting the need for FCT to make a correct diagnosis. TRIAL REGISTRATION: The present study was conducted as a sub-analysis of the AID-ANGIO trial (ClinicalTrials.gov NCT056359949).