Late Outcomes of Postoperative Complete Heart Block After Congenital Heart Surgery: Recovery or Recurrent Heart Block?

Abstract

Postoperative complete heart block (CHB) constitutes a complication of congenital heart surgery, requiring a permanent pacemaker (PPM). This study aimed to determine the incidence of postdischarge recovery from CHB after PPM implantation and the incidence of recurrent CHB after initial recovery. The cumulative incidences of recovery from CHB and postdischarge recurrent CHB after 9892 congenital cardiac operations between 2001 and 2024 were analyzed. A Cox regression model was used to identify predictors of recovery from CHB and recurrent CHB. Of 327 patients with CHB, 193 (59.0%) required a PPM within the same hospital stay, and 134 (41.0%) were discharged without a PPM because of complete recovery. Postdischarge recovery of atrioventricular conduction was observed in 32 of 193 (16.6%) patients with a PPM (median period of 3.8 [0.3-6.3] years). The type of recovery included 22 sinus rhythms, 8 first-degree, and 2 second-degree atrioventricular blocks. Postdischarge recurrent CHB requiring PPM was observed in 11 of 134 (8.2%) patients with a median period of 0.6 (0.2-4.7) years. The cumulative incidence of recovery and late PPM implantation at 10 years was 24.2% and 9.5%, respectively. Neonatal operation (hazard ratio [HR], 4.491; P = .018), longer recovery time with an 8-day threshold (HR, 1.107; P = .022), and catheter intervention (HR, 4.587; P = .025) were risk factors for postdischarge recurrent CHB. Our findings support the current class 1 guidelines for pacemaker implantation after 7 days of CHB. Postdischarge recurrent CHB is difficult to predict in individual patients and can be manifested many years postoperatively, supporting lifelong follow-up after congenital heart surgery.