Exercise Stress Cardiac MRI is Feasible in Adolescents and Young Adults with Anomalous Coronary Arteries.

Aims: Anomalous aortic origin of a coronary artery (AAOCA) can result in sudden cardiac death in the young and risk stratification is challenging. Though dobutamine stress cardiac magnetic resonance (DS-CMR) is feasible in pediatric patients, exercise stress CMR (ES-CMR) may have lower rates of adverse events, higher diagnostic accuracy, and the ability to better reflect the physiologic changes occurring with exercise. We aimed to describe our institution's experience with ES-CMR using supine bicycle ergometry in pediatric and young adult patients with AAOCA.

Methods and results: We retrospectively reviewed the medical records of AAOCA patients who underwent ES-CMR at our institution between 2011 and 2024 for demographic, clinical presentation, cardiopulmonary exercise test (CPET) and ESCMR data. The exercise-based portion of the CMR consisted of supine cycle ergometry utilizing a ramp protocol, immediately after which ES perfusion imaging was performed. Fifteen minutes after stress imaging, rest perfusion imaging was acquired.Of 38 patients who underwent ES-CMR, the median age was 16 years (range 13-24) and 68% were male. Diagnoses included anomalous right coronary artery (n=28),anomalous left coronary artery (n=8), and single coronary artery (n=1 single right, n=1single left). Median maximal heart rate (HR) during ES-CMR was 160 bpm (range 130-190, median 80% predicted) compared to a median maximal HR during patients' most recent CPET of 187 bpm (range 160-203, median 97% predicted). No patients had perfusion defects at rest or with exercise stress, or evidence of myocardial scarring.

Conclusions: We demonstrate for the first time the use of ES-CMR in a cohort of pediatric and young adult patients with AAOCA. ES-CMR is a unique modality to assess for ischemia at rest and stress to assist with risk stratification by simulating physiologic changes with exercise stress. Although maximum heart rates during supine cycle ergometry are lower than those reached during CPET, they are similar to those reached during DS-CMR. ES-CMR is a valuable diagnostic tool and may be useful in the risk stratification of patients with AAOCA.