P088 - WHAT REALLY PREDICTS CORONARY VASOSPASM AND MICROVASCULAR DYSFUNCTION? CHALLENGING TRADITIONAL PARADIGMS.

Background: Angina with No Obstructive Coronary Arteries (ANOCA) from coronary vasomotor dysfunction has traditionally been viewed as elusive, associated with young, female patients without classic atherosclerotic risk factors. Indeed, referral patterns to specialized coronary vasomotor testing mirror this perception. Yet this paradigm has recently come under scrutiny, as emerging data suggest a correlation between traditional atherosclerotic risk factors and coronary vasomotor dysfunction.

METHODS AND RESULTS: Our aim was to identify the clinical criteria that best predict vasomotor dysfunction (epicardial vasospasm, microvascular functional and structural dysfunction) and compare this with assumed associations with coronary vasomotor dysfunction, and conversely traditional risk factors for coronary artery disease.
Of the 409 patients in this prospective, single‐centre study of all patients referred for invasive coronary vasomotor testing for ANOCA, 269 (65.8%) had at least one type of vasomotor dysfunction. Patients with a vasomotor abnormality were older than those without (59.0±10.93 vs. 57.5±10.96 years; p< 0.05), and there were no significant sex differences between the groups. The presence of epicardial vasospasm correlated with prior myocardial infarction (39% vs. 24.7%; p< 0.05). Isolated Coronary Flow Reserve (CFR) abnormality best reflected the typically referred group, with highest likelihood of being female and of younger age, and this group also demonstrated the lowest Duke Treadmill Score. On the other hand, isolated Index of Myocardial Resistance (IMR) abnormality was associated with older age, higher rates of hypertension and hyperlipidemia. The combination of abnormal CFR and abnormal IMR conferred in the greatest prevalence of traditional atherosclerotic risk factors.

Conclusion: In patients with angina and non‐obstructive coronary arteries, typical referral triggers—younger age, female sex, Caucasian ethnicity, and absence of hypertension or hyperlipidemia—did not consistently predict the presence of coronary vasomotor dysfunction. The subgroup that most closely resembled the referred cohort was that of abnormal CFR yet normal IMR. This group also demonstrated the worst Duke Treadmill Score.