Prognostic Implications of Progressive Systemic Ventricular Dysfunction in Congenitally Corrected Transposition of Great Arteries

Objectives: The purpose of this study was to determine the risk factors for and prognostic implications of progressive right ventricular systolic dysfunction (RVD) in adults with congenitally corrected transposition of great arteries. Background: There are no effective therapies for RVD; hence the need to identify and modify risk factors for progressive RVD. Methods: RV systolic function was assessed by using RV longitudinal strain (RV-LS). The first echocardiogram (baseline echocardiogram) and all subsequent annual echocardiograms performed within 5 years from the baseline echocardiogram were analyzed. Progressive RVD (temporal decline in RV-LS) was assessed as the average annual change in RV-LS within 5 years of imaging follow-up. Results: Of 186 patients (mean age 40 ± 12 years), the RV-LS at baseline was –17% ± 4%, and the annual decline in RV-LS was –4% (95% CI: –6 to –2). The risk factors for progressive RVD were left ventricular (LV) systolic dysfunction, LV pacing, and systemic hypertension. Cardiovascular events (heart failure hospitalization, heart transplant, and death) occurred in 57 (27%) patients. Progressive RVD was associated with cardiovascular events, independent of RV systolic function at baseline. In subgroup analyses assessing impact of therapies (medical therapy, cardiac resynchronization therapy, and tricuspid valve replacement), only tricuspid valve replacement was associated with improvement in RV systolic function when performed before onset of RVD. Conclusions: Patients with congenitally corrected transposition of great arteries were at risk for progressive RVD, and the risk factors for progressive RVD were LV pacing, systemic hypertension, and concomitant LV dysfunction. Further studies are required to determine whether strict blood pressure control and early tricuspid valve replacement will prevent progressive RVD.