Myocardial bridges in a pediatric population: Outcomes following a standardized approach.

Objective: To describe clinical, functional, surgical, and outcomes data in pediatric patients with a myocardial bridge (MB) evaluated and managed following a standardized approach.

Methods: Prospective observational study included patients evaluated in the Coronary Artery Anomalies Program. Anatomy was determined by computed tomography angiography, myocardial perfusion by stress perfusion imaging, and coronary hemodynamic assessment by cardiac catheterization.

Results: In total, 39 of 42 patients with a complete evaluation for MB were included (December 2012 to June 2022) at a median age of 14.1 years (interquartile range, 12.2-16.4). Sudden cardiac arrest occurred in 3 of 39 (8%), exertional symptoms in 14 (36%), and no/nonspecific symptoms in 7 (18%) patients. Exercise stress test was abnormal in 3 of 34 (9%), stress perfusion imaging in 8 of 34 (24%), and resting instantaneous wave-free ratio ≤0.89 or diastolic dobutamine fractional flow reserve ≤0.80 in 11 of 21 (52%) patients. As a result, 15 of 39 (38%) patients were determined to have hemodynamically significant MB, 1 of 15 patients started beta-blocker, and 14 of 15 were referred for surgery. Myotomy (n = 11) and coronary bypass (n = 1) were performed successfully, resulting in improved symptoms and stress testing results. One patient required pericardiocentesis postoperatively, and all were discharged without other complications. At median follow-up time of 2.9 (1.8-5.8) years, all (except 2 pending surgery) were doing well without exercise restriction.

Conclusions: Pediatric patients with MB can present with myocardial ischemia and sudden cardiac arrest. Provocative stress test and intracoronary hemodynamic tests helped risk-stratify symptomatic patients with MB and concern for ischemia. Surgical repair was safe and effective in mitigating exertional symptoms and stress test results, allowing patients to return to exercise without restriction.