Angina with non-obstructive coronary arteries and myocardial bridge: long-term outcomes of surgical unroofing

BACKGROUND AND AIMS: A myocardial bridge (MB) can cause angina in patients with non-obstructive coronary arteries. For patients with a functionally significant MB and severe angina despite maximal medical therapy, surgical unroofing improves short-term symptoms and quality of life (QoL). This study evaluated long-term clinical and symptomatic outcomes of surgical unroofing of a functionally significant left anterior descending artery MB. METHODS: Two hundred eighteen adult patients who underwent surgical unroofing for an MB were prospectively followed. Preoperative assessments included stress echocardiography, coronary computed tomography angiography, invasive coronary angiography, and intravascular ultrasound. A functionally significant MB was defined as dobutamine-stress diastolic fractional flow reserve (dFFR) and/or resting full-cycle ratio (RFR) ≤ 0.76. The Seattle Angina Questionnaire (SAQ) assessed symptoms and QoL at baseline and follow-up. Additionally, among those with a functionally significant MB, 65 surgically unroofed patients were matched with 65 patients who did not undergo surgery using propensity score matching. RESULTS: The median follow-up was 5 (3-9) years. At follow-up, patients reported significant and highly clinically meaningful improvement in all SAQ domains-physical limitation, anginal stability, anginal frequency, treatment satisfaction, QoL, and SAQ summary score. Unroofed patients reported a significantly greater improvement in physical limitation (27.8 vs 11.4, P = .004) and angina frequency (30 vs 20, P = .01) than the non-surgical patients. CONCLUSIONS: Surgical unroofing of a symptomatic and functionally significant MB is associated with significant long-term improvement in symptoms and QoL. For patients with severe angina and failed medical management who have a functionally significant MB, surgical unroofing is a beneficial treatment strategy.