Abstract 16329: Survival Prospects in Congenitally Corrected Transposition of the Great Arteries: Results From a Multi-institutional Study

Background: Occasionally patients with congenitally corrected transposition of the great arteries (ccTGA) exhibit little clinical evidence of cardiovascular limitation even to their 8th decade. We aimed to assess survival prospects in a large cohort of ccTGA adults. Methods & Results: We included 555 ccTGA adults (median age 33.0 years, 48.3% female) under regular follow-up at 28 institutions between 2002 and 2019. The primary outcome was a composite of death, mechanical circulatory support (MCS) and heart transplant. During a median follow-up of 8.1 [IQR 4.4 - 13.3] years, 56 (10.1%) patients died, 10 (1.8%) patients underwent MCS and 14 (2.5%) had a heart transplant. Median age at time of primary outcome was 51.1 [IQR 37.5 - 63.2] years and cumulative incidence at 15 years from baseline was 21.5% [95% CI 16.1 - 26.5]. Leading causes of death were worsening of heart failure (43%) and sudden death (10%). Patients who died were more likely to use heart failure (HF) medications. In multivariable Cox analyses for baseline variables, age, prior atrial arrhythmia and HF admission were each associated with an increased risk of the primary outcome. Figure shows cumulative incidence according to history of atrial arrhythmia. During follow-up, 91 (16.4%) were admitted for HF, pacemaker implantation was performed in 68 (12.3%) patients, ICD in 82 (14.7%), and major cardiac surgery (mostly for systemic AV-valve) in 89 (15.8%) patients. Conclusion: In this large cohort of ccTGA adults, survival seemed to be primarily determined by heart failure-related complications. Prior atrial arrhythmia also seems to be a harbinger for adverse outcome. Few patients underwent advanced HF therapies. Figure: Cumulative incidence of the composite primary outcome (MCS, heart transplant or death) over a period of 14 years from first visit at an adult congenital heart disease clinic since 2002 stratified according to history of atrial arrhythmia. Shading represents upper and lower 95% confidence limits.