Abstract 14198: Anatomic Repair of Congenitally Corrected Transposition of the Great Arteries is Associated With Significant Mid- and Long-term Electrophysiologic Morbidity

Abstract

Introduction: Limited data exist on the electrophysiologic outcomes of patients undergoing anatomic repair (AR) for congenitally corrected transposition of the great arteries (ccTGA). AR was defined as an atrial switch procedure plus either arterial switch (ASO) or Rastelli operation. Aims: To report mid and late electrophysiologic outcomes after AR and identify risk factors for those outcomes. Methods: Single center retrospective cohort study of patients undergoing AR between 1993-2017. Data were collected from available records. Transplant-free survival to 1 year post repair was required for inclusion. Standard descriptive statistical analysis and Cox proportional hazards were used. Results: Of 85 patients included, 95% had lesions in addition to ccTGA: most commonly VSD (84%) and pulmonary stenosis or atresia (58%). Median age at AR was 1.5y (IQR 0.9-2.8) with Senning/ASO in 56%, Senning/Rastelli in 38%, and hemi-Senning/Glenn/Rastelli in 6%. During a median follow-up of 10.6y, 45 (53%) patients developed an arrhythmia requiring intervention. Atrial tachycardia (AT) in 27 (32%) or ventricular tachycardia (VT) in 11 (13%) patients required intervention at a median of 7.4y (IQR 1.6-15.3y) and 15.9y (IQR 4.5-17.9) post-AR, respectively. Treatments included chronic medications in 29 (64%), cardioversion in 15 (33%) and catheter ablation in 10 (22%). Median freedom from AT and VT was 17.3y and 25y post-AR, respectively. D-looped ventricles (p=0.03) and multiple operations prior to AR (p=0.02) were associated with increased AT risk; and native pulmonary stenosis with increased VT risk (p=0.01). Those needing heart failure/transplant referral had increased risk of both AT and VT (both p=0.04). Pacemaker was implanted for heart block and/or SND prior to or during AR in 14 (16%), immediately post-op in 9 (11%), and late (median 6y post-AR) in 24 (28%). ICDs were implanted in 5 (6% of cohort), 4 for primary prevention. No patient had an appropriate shock. Conclusions: Anatomic ccTGA repair is associated with significant electrophysiologic morbidity. AT, VT, and SND develop at a similar incidence to that reported for d-TGA patients after atrial switch. The incidence of AV block follows a similar trajectory to that of physiologically palliated ccTGA.