Background: Heart block (HB) can complicate congenital heart disease (CHD) surgery and require pacemaker (PM). Adverse consequences of chronic ventricular pacing are increasingly recognized.
Objective: To evaluate the effect of PM implantation on long-term transplant-free survival of patients with two-ventricle (2V) CHD.
Methods: We queried the Pediatric Cardiac Care Consortium (PCCC), a large US-based registry, for patients ≤ 21 yrs old undergoing surgery for 2V CHD with risk for HB and receiving PM within 90 days, and identified control patients matched by sex, CHD, operation, age at surgery and surgical era. Primary outcome was transplant-free survival via linkage to the National Death Index and Organ Procurement and Transplantation Network.
Results: We identified 395 patients and 775 controls. Median age at surgery was 2.1 yrs (32% infants, 52% male). The most common diagnosis associated with PM implantation was AV Canal (28%) followed by VSD (27%). Among patients surviving to hospital discharge, PM implantation was associated with decreased transplant-free survival reaching peak statistical significance at 20 yrs follow up (p = <0.0001). Analyzing by surgical era, survival was 72% vs 81% during 1982-1992 compared to 76% vs 81% during 1993-1997.
Conclusion: Surgical HB needing PM insertion after 2V CHD surgery is associated with diminished long-term transplant-free survival. Studying the mechanisms of this association (e.g. dyssynchrony, tachyarrhythmias or hardware complications) may identify opportunities to improve outcomes using either existing or emerging technology.