Abstract 16391: Systemic Ventricular Dysfunction and Long Term Outcomes in Patients With D-transposition of the Great Arteries (D-TGA), Atrial Switch, and Systemic Right Ventricle Physiology

Abstract

Introduction: Patients with D-TGA palliated with atrial switch operations have the morphologic right ventricle in the systemic position. There is increased risk of atrial arrhythmias and systemic right ventricle (SRV) failure. We sought to analyze the long term outcomes of these patients. Methods: All patients with D-TGA and SRV followed in the Adult Congenital Heart Disease Clinic of a large tertiary care institution were reviewed. A comprehensive retrospective analysis of the medical record was performed, including consult notes, ECGs, echocardiograms and electrophysiology reports. Results: A total of 154 patients (63% male) aged 29±11 years were followed for a mean of 10±9 years (range 0-51). During follow-up, 3 patients underwent cardiac transplantation and 15 died; 5 had sudden death, 2 had cardiogenic shock, 5 had non-cardiac death (i.e., infective endocarditis, sepsis) and 3 had unknown causes of death. Heart failure symptoms were present in 53(34%) patients. Severe SRV systolic dysfunction occurred in 37(24%) patients, with a mean EF of 23±5.5%; moderate SRV dysfunction occurred in 67(44%) patients, mean EF 35±4%. Sinus node dysfunction was present in 75(49%) patients, complete AV block in 9(5%) patients, and a pacemaker placed in 60(39%) patients, with cardiac resynchronization therapy in 5. Atrial arrhythmias occurred in 94(61%) patients and ablations were performed in 47(31%) patients. An ICD was implanted in 37 patients; 5 patients had appropriate shocks, but 7 had inappropriate shocks due to atrial arrhythmias. Age (HR 1.07, p=001), heart failure symptoms (HR 4.9, p= 0.007), severe SRV enlargement (HR 3.7, p=0.03), severe systolic dysfunction (HR 5.4, p=0.003), severe systemic AV valve regurgitation (HR 5.2, p=0.002) and a QRS duration> 122ms (HR 3.7, p=0.02) were significant predictors of mortality. The 15 year probability of sudden death was 3.2%(95% CI 0-6.9%). Conclusions: Atrial arrhythmias are common after atrial switch operations secondary to atriotomy scars. Further studies will need to determine whether restoration of sinus rhythm or cardiac synchrony may prevent further deterioration of the systemic right ventricle. Severe SRV dysfunction and prolonged QRS duration >122ms were significantly correlated with mortality.