Risk Prediction in Transposition of the Great Arteries

Quick Takes

  • Major adverse ventricular arrhythmias and related events (MAREs) in patients with transposition of the great arteries and a systemic right ventricle occurred at a rate of 6.3 events per 1,000 patient-years.
  • Age, history of heart failure, syncope, QRS duration, severe systemic RV dysfunction, and at least moderate LVOT obstruction significantly impacted risk of MARE.
  • The authors include a link to a risk calculator in the online supplement.

Study Questions:

Can we improve risk stratification for primary prevention implantable cardioverter-defibrillator (ICD) use in congenital heart disease in adults with a systemic right ventricle (sRV)?


This was a retrospective observational study on patients with transposition of the great arteries (TGA) and an sRV, including parameters potentially increasing risk based on literature review. The primary endpoint was occurrence of a major adverse ventricular arrhythmia and related event (MARE): sudden cardiac death, sustained ventricular tachycardia, or appropriate ICD therapy. Univariate followed by multivariate regression analysis was completed and a risk calculator derived from key risk factors.


There were 1,184 patients included (70% complete TGA [D-TGA], 30% congenitally corrected TGA [L-TGA]). Mean age was 27 (interquartile range, 20-35) years. MAREs occurred in 59 patients (5%) during a median 9.4 years of follow-up. The overall incidence of MAREs was 6.3 per 1,000 patient-years. Significant risk factors included older age, history of heart failure, syncope, longer QRS duration, severe RV dysfunction, and left ventricular outflow tract (LVOT) obstruction. The derived clinical calculator was then applied to the group and patients were categorized into low (<5%), intermediate (5-10%), and high (>10%) risk for MARE. High-risk patients had a 20% predicted risk and a 24% observed occurrence of a MARE. The final model (available as a calculator in the online article supplement) had a c-statistic of 0.78. Discriminatory ability was better with D-TGA than in L-TGA.


This prediction model may be used to improve identification of patients who may benefit from primary prevention ICD implantation.


Risk predication for sudden cardiac death and ventricular arrhythmias in complex congenital heart disease is challenging due to limited research data. This risk analysis and calculator establish a good starting point to improve stratification, but will require external validation.

Clinical Topics: Arrhythmias and Clinical EP, Congenital Heart Disease and Pediatric Cardiology, Heart Failure and Cardiomyopathies, Prevention, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Congenital Heart Disease, CHD and Pediatrics and Arrhythmias, CHD and Pediatrics and Prevention, CHD and Pediatrics and Quality Improvement, Acute Heart Failure

Keywords: Arrhythmias, Cardiac, Death, Sudden, Cardiac, Defibrillators, Implantable, Heart Defects, Congenital, Heart Failure, Primary Prevention, Risk Assessment, Risk Factors, Syncope, Tachycardia, Ventricular, Transposition of Great Vessels, Ventricular Dysfunction, Right, Young Adult

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