Cardiac Resynchronization Therapy in Congenital Heart Disease Patients with Systemic Right Ventricle

Abstract Background Although patients with systemic right ventricle (SRV) represent a significant proportion of patients with congenital heart disease (CHD) implanted with cardiac resynchronization therapy (CRT), there are very limited and conflicting data in this specific patient group. Objectives We aimed to analyze outcomes of patients with SRV implanted with CRT. Methods Data were analyzed from an observational, retrospective, multicenter cohort study including all CHD patients implanted with a CRT device from 6 French centers from 2004 to 2020. Response to CRT was defined as an increase in systemic ventricular ejection fraction ≥10% and/or an improvement ≥ one NYHA functional class. Results A total of 85 CHD patients were enrolled (mean age 39.8±20.0 years, 64.7% males, 25 [29.4%] defibrillators), including 31 (36.5%) patients with SRV (43.9±19.8 years, 51.6% males). The mean change in QRS duration after implantation was similar as compared to patients with systemic left ventricle (-46±26 ms vs. -35±32 ms, p=0.16). During a mean follow-up of 5.1±3.5 years, late complications included 2 (6.5%) lead dysfunctions, 3 (9.7%) CRT-related infections, and 1 (3.2%) inappropriate ICD shock. The proportion of CRT responders at 6-month, 12-month, and 24-month were 82.6%, 80.0%, and 77.8% in patients with SRV vs. 66.7%, 64.3%, and 69.6% in patients with systemic left ventricle (p=NS). Conclusions In this multicenter cohort, one third of CHD patients implanted with a CRT had a SRV. CRT in SRV patients was associated with a high rate of responders, comparable to that of patients with systemic left ventricle.