Equivalent performance of epicardial versus endocardial permanent pacing in children: a single institution and manufacturer experience.

BACKGROUND: Children requiring permanent pacing have a lifelong need for follow-up. Epicardial leads have traditionally fared worse than endocardial counterparts. We tested the hypothesis that steroid-eluting epicardial and endocardial leads had equivalent outcomes.
METHODS: We reviewed medical records of 148 children, mean age 8.2 +/- 4.8 years, in whom a dual-chamber pacemaker system with steroid-eluting leads from a single manufacturer was implanted. Primary outcome was mortality. Secondary outcomes included freedom from lead failure and pacemaker system reintervention. Loss of capture-sensing, lead displacement-fracture, exit block, and high thresholds constituted lead failure. Reintervention included need for lead revision or generator change.
RESULTS: There was no early mortality. Late mortality occurred once (0.5 +/- 0.5 deaths/1,000 patient-months) and eight times (3.4 +/- 1.2 deaths/1,000 patient-months) in the endocardial and epicardial groups, respectively. The relative hazard of endocardial versus epicardial site for lead failure was 0.408 (p = 0.038) and for reintervention was 0.629 (p = 0.002). Endocardial and epicardial groups differed in important ways: concomitant cardiac surgery 5% (3 of 61) versus 27% (27 of 99); congenital heart disease 33% (20 of 61) versus 90% (89 of 99); single ventricle physiology 13% (8 of 61) versus 52% (51/99); and age (10.5 +/- 4.5 years vs 5.5 +/- 5.2 years). Adjusting for these covariants, the relative hazard for freedom from lead failure for endocardial versus epicardial leads was 0.546 (p = 0.360). The adjusted relative hazard for freedom from reintervention was 0.157 (p = 0.045).
CONCLUSIONS: Technologic advances attenuate important differences in lead failure rates between endocardial and epicardial steroid-eluting pacing leads and thus bridge the performance gap between these fixation modes.