Long‐Term Outcome of Patients With Congenital Heart Disease Undergoing Cardiac Resynchronization Therapy

Background Cardiac resynchronization therapy (CRT) is rarely used in patients with congenital heart disease, and reported follow‐up is short. We sought to evaluate long‐term impact of CRT in a single‐center cohort of patients with congenital heart disease. Methods and Results Thirty‐two consecutive patients with structural congenital heart disease (N=30) or congenital atrioventricular block (N=2), aged median of 12.9 years at CRT with pacing capability device implantation, were followed up for a median of 8.7 years. CRT response was defined as an increase in systemic ventricular ejection fraction or fractional area of change by >10 units and improved or unchanged New York Heart Association class. Freedom from cardiovascular death, heart failure hospitalization, or new transplant listing was 92.6% and 83.2% at 5 and 10 years, respectively. Freedom from CRT complications, leading to surgical system revision (elective generator replacement excluded) or therapy termination, was 82.7% and 72.2% at 5 and 10 years, respectively. The overall probability of an uneventful therapy continuation was 76.3% and 58.8% at 5 and 10 years, respectively. There was a significant increase in ejection fraction/fractional area of change ( P <0.001) mainly attributable to patients with systemic left ventricle ( P =0.002) and decrease in systemic ventricular end‐diastolic dimensions ( P <0.05) after CRT. New York Heart Association functional class improved from a median 2.0 to 1.25 ( P <0.001). Long‐term CRT response was present in 54.8% of patients at last follow‐up and was more frequent in systemic left ventricle ( P <0.001). Conclusions CRT in patients with congenital heart disease was associated with acceptable survival and long‐term response in ≈50% of patients. Probability of an uneventful CRT continuation was modest.