Abstract 4135259: Coronary Artery Anomalies Induce Myocardial Ischemia in Hypertrophic Cardiomyopathy

Background: Myocardial ischemia is a frequent finding in hypertrophic cardiomyopathy (HCM) and is often attributed to microvascular disease, extravascular compressive forces, reduced coronary flow reserve, hemodynamic abnormalities, and concomitant atherosclerotic coronary artery disease (CAD). The potential contribution of congenital coronary artery anomaly (CCAA) to myocardial ischemia in HCM has not been systematically explored. Research Question: We aimed to evaluate the spectrum and potential contribution of CCAA to myocardial ischemia in HCM. Methods: From June 1991 to March 2023 a total of 35 CCAA were reported in 29 adults [age 18-87 (47.9±19.9; 59% male; 35% obstructive, 21% apical variant). Clinical data on presence or absence of myocardial ischemia, mode of therapy, and outcomes of the patients were reviewed. Results: The individual CCAAs were graphically reproduced [Figure] and were categorized based on the number of coronary ostia present in the aorta [single ostium (n=11; 38%); 2 ostia (n=13; 45%); 3 ostia (n=4; 14%); 4 ostia (n=1; 3%)]. The anomalous coronary artery was the left main in 6 (17%); left anterior descending in 6 (17%); left circumflex in 8 (23%); right in 14 (40%) or the ramus intermedius in 1 (3%). Two patients (7%) with apical variant HCM also had coronary artery fistulae in a non-anomalous coronary artery. Of all 29 patients who presented, 12 (41%) showed objective evidence of myocardial ischemia and of those, a total of 6 (50%) had an anomalous coronary artery coursing between the great vessels. In addition, 1 of 5 patients with sudden cardiac arrest had a high-risk coronary anomaly. Pharmacologic treatment was offered to 11 (38%) patients and 3 (10%) patients underwent coronary artery surgery (bypass grafting in 2 and unroofing in 1). Septal reduction therapy was performed in 8 (28%). Follow up data was available in 14 patients including 2 of the 3 who underwent surgical correction. Symptomatic improvement was noted in all 14. Conclusion: Congenital coronary artery anomalies may be present in patients with HCM and may contribute to myocardial ischemia. Treatment options depend on the type of anomaly and presence of objective evidence of myocardial ischemia.