Objectives: Cardiac resynchronization therapy (CRT) is rarely used in pts with congenital heart disease (CHD) and follow-up in available studies is short. We sought to evaluate long-term impact of CRT in pts with CHD.
Patients and methods: Thirty consecutive pts with structural CHD (N=28) or congenital atrioventricular block (N=2) aged median 12.9 (IQR 6.5-18.2) years at CRT-P implantation were followed for median 9.0 (IQR 4.5-11.4) years on CRT. CRT was performed for systemic left ventricular (LV, N=12) and right (RV) or single (SV) ventricular (N=18) failure and was associated with additional cardiac surgery in 13 pts. CRT response was defined as an increase in systemic ventricular ejection fraction or fractional area of change (FAC) by >10 points and improved or unchanged NYHA class at the end of follow-up. Actuarial survival probability was calculated for 5 and 10 years after CRT implantation.
Results: Freedom from cardiovascular death or heart failure hospitalization was 92.0 and 82.3 %, resp. No patient underwent heart transplant. Freedom from CRT complications leading to surgical system revision (elective generator replacement excluded) or therapy termination was 81.4 and 70.1 % at 5 and 10 years, resp. Overall probability of an uneventful therapy continuation was 74.6 and 56.3 %, resp. Ejection fraction or FAC changed from median 29.5 % (IQR 22.3-35.0) before CRT to median 40.3 % (IQR 32.0-54.0; p<0.001) at the end of follow-up. NYHA class improved from median 2.0 to 1.5 (p=0.002). CRT response tended to be more frequent in systemic LV (9/12 pts) than RV or SV (6/18 pts, p=0.060).
Conclusions: Long-term CRT in pts with CHD is associated with acceptable survival and sustained improvement of systemic ventricular function in 50 % of pts. Probability of device complications necessitating surgical revision or therapy termination is however high.