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.