Impact of permanent pacemaker for iatrogenic atrioventricular block on outcomes after congenital heart surgery

The need for permanent pacemaker (PPM) for iatrogenic atrioventricular block (AVB) after congenital heart surgery is approximately 1%. We aimed to evaluate the long-term outcomes of patients with PPM for iatrogenic AVB and compare them with patients with an optimal repair (trivial/no residual) Residual Lesion Score (RLS) Class 1 repair without PPM need.

We reviewed 183 patients discharged with PPM for iatrogenic AVB from 2011 to 2022. Patients who survived to discharge with >30 days of follow-up were matched 1:1 with a cohort of patients categorized as RLS Class 1 on the basis of fundamental diagnosis and primary procedure.

Median age at PPM placement was 1.4 years (interquartile range, 4.3 months to 3.9 years). The cumulative incidence of moderate or greater ventricular dysfunction at 1 year and 5 years was 11% and 18% in patients with PPM, respectively, compared with 3% and 7% in patients categorized as RLS Class 1 (subdistribution hazard ratio, 2.6; 95% confidence interval, 1.2-6.1; P = .022). Independently, patients with PPM with hypoplastic left heart syndrome (P = .027) and who had undergone Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Mortality Category 5 procedures (P = .033) were at greater risk of ventricular dysfunction. Transplant-free survival at 1 year and 5 years was 94% and 89% in patients with PPM, respectively, compared with 98% and 97% in patients categorized as RLS Class 1 (P = .044). In addition, patients with PPM with palliated circulation had significantly lower transplant-free survival (P < .001).

Compared with patients with an optimal repair without PPM, patients with PPM for iatrogenic AVB are at greater risk of developing moderate or greater ventricular dysfunction and have lower transplant-free survival.