Abstract 17826: Long-term Survivors With Transposition of the Great Arteries After Arterial Switch Operation Show No Signs of Adverse Myocardial Remodeling

Background: The arterial switch operation (ASO) for transposition of the great arteries (TGA) involves coronary translocation. The altered coronary geometry may lead to subclinical myocardial ischemia, which may result in myocardial scarring and diffuse myocardial fibrosis. We hypothesized that myocardial fibrosis is present late after ASO, despite excellent functional outcomes of the ASO in most patients. Methods: 30 pediatric TGA patients after ASO were prospectively studied by cardiac magnetic resonance imaging (CMR). Late gadolinium enhancement (LGE) was used to detect discrete myocardial scarring. Native T1 relaxation times and extracellular volumes (ECVs) at the mid-ventricular short-axis level of the left ventricle (LV) were used to quantify diffuse myocardial fibrosis. The midventricular short-axis slice was divided into 6 segments. Patients were compared to 21 healthy controls. Results: Mean ages at ASO and at CMR were 6.3±5.2 days and 15.4±2.9 years, respectively. Mean age of controls at CMR was...