Is exercise stress testing useful for risk stratification in anomalous aortic origin of a coronary artery?

Data on maximal exercise-stress-testing (m-EST) in anomalous-aortic-origin-of-coronary-arteries (AAOCA) is limited and correlation with stress perfusion imaging has not been demonstrated. AAOCA patients ≤20 years were prospectively enrolled from 6/2014-01/2020. A m-EST was defined as heart rate >85%ile on ECG-EST and respiratory-exchange-ratio (RER) ≥1.05 on cardiopulmonary-exercise-testing (CPET). Abnormal m-EST included significant ST-changes or high-grade arrhythmia, ໿V̇O2max and/or O2 pulse <85% predicted, or abnormal O2 pulse curve. A (+) dobutamine-stress cardiac-magnetic-resonance-imaging (+DS-CMR) had findings of inducible-ischemia. Outcomes: 1) Differences in m-EST based on AAOCA-type; 2) Assuming DS-CMR as gold-standard for detection of inducible ischemia, determine agreement between m-EST and DS-CMR. A total of 155 AAOCA (right, AAORCA = 126; left, AAOLCA = 29) patients with a median (IQR) age of 13 (11 - 15) years were included; 63% were males and a m-EST was completed in 138 (89%). AAORCA and AAOLCA had similar demographic and m-EST characteristics, although AAOLCA had more frequently evidence of inducible ischemia on m-EST (p=0.006) and DS-CMR (p=0.007). Abnormal O2 pulse was significantly associated with +DS-CMR (OR 5.3, 95% CI 1.6 -18, p=0.005). Sensitivity was increased with addition of CPET to ECG-EST (to 58% from 19%). There was no agreement between m-EST and DS-CMR for detection of inducible ischemia. A m-EST has very low sensitivity for detection of inducible ischemia in AAOCA, and sensitivity is increased with addition of CPET. Stress perfusion abnormalities on DS-CMR were not concordant with m-EST findings and adjunctive testing should be considered for clinical decision making in AAOCA.