Dobutamine Stress Cardiac MRI in Pediatric Patients with Suspected Coronary Artery Disease

Following current practice, pediatric patients with treated congenital coronary malformations or acquired coronary disease undergo Cardio-Pulmonary Exercise Test (CPET), stress Echocardiography and Electrocardiography (sEcho, sEKG), and Coronary Angiography (CA). Stress cMRI can assess cardiac function, myocardial viability, and stress/rest perfusion deficit-without radiation exposure, general anesthesia, and hospitalization-in a single non-invasive exam. The aim of our pilot study is to assess the feasibility and diagnostic accuracy of Dobutamine stress cMRI compared to the current procedures (sEcho, CPET, CA). The prospective study is focused on pediatric patients, at risk for or with previously diagnosed coronary artery disease: d-looped TGA after arterial Switch, Kawasaki disease, and anomalous origin of left coronary artery from pulmonary artery (ALCAPA) after coronary artery reimplantation. We have compared the results of MRI coronary angiography, and Dobutamine stress cMRI with traditional tests. All these diagnostic exams were acquired in a timeframe of 3 month, in a blinded fashion. All the 13 patients (age: 12 ± 2 years, median 12,7 y) recruited, completed the study without major adverse events. The mean heart rate-pressure product was 25,120 ± 5110 bpm x mm Hg. The target heart rate of 85% of the maximal theoretical was reached by 10 (77%) patients. The comparison between cardiac MRI coronarography versus the gold standard Coronary Angiography to identify the patency of the origin and the proximal pathway of the coronary arteries shows a sensitivity of 100% (confidence interval: 2,5-100%), specificity 92% (confidence interval: 64-100%). The stress test was well tolerated for the 77% of the patients and completed by the totality of patients (Table 3). Three patients (23%) had mild symptoms: nausea, vomiting, or general discomfort. In pediatric patients with a potential or definite diagnosis of coronary artery disease, stress cMRI combines an effective assessment of proximal coronary arteries anatomy with cardiac function, myocardial perfusion, and viability in a single examination. Stress cMRI can be proposed as alternative, standalone test.