Long-term performance of conduction system pacing in patients with congenital heart disease

Conduction system pacing (CSP) is safe and feasible in congenital heart disease (CHD), but long-term follow-up data remain scarce.

This study aimed to evaluate the long-term performance of CSP in patients with CHD.

This retrospective, multicenter, international study included patients with CHD undergoing CSP-His bundle pacing or left bundle branch area pacing (LBBAP)-with ≥12-month follow-up. The primary endpoint was survival free from CSP lead-related complications (loss of conduction system capture, pacing threshold ≥2.5 V or a ≥2.0 V increase, or lead reintervention). Secondary endpoints included implant success, electrical and echocardiographic outcomes, and clinical status.

144 patients were included (88% moderate/complex CHD; 26% systemic right ventricle; 24% with cardiac resynchronization therapy indication), with 29 His bundle pacing and 115 LBBAP. Acute implant success was 95.1%. Over a median follow-up of 32.2 months (interquartile range 18.2-47.1), survival free from CSP lead-related complications was 0.89, with 88% of CSP lead-related events occurring beyond 12 months of follow-up. Device-related complications occurred in 11.8%, and reinterventions in 5.1%. Microdislodgement (14.6%), threshold increase (6.9%), and loss of conduction system capture (5.6%) were less frequent with LBBAP. Left ventricular ejection fraction improved in patients with systemic left ventricle, whereas patients with a systemic right ventricle preserved fractional area change. Among patients with cardiac resynchronization therapy indications, systemic ventricular function improved from 34% ± 10% to 41% ± 13% (P < .001).

CSP is feasible across a broad spectrum of CHD and is associated with preservation or improvement of systemic ventricular function. Late lead-related complications are not negligible, underscoring the need for long-term follow-up.