PO-01-025 EPICARDIAL LEAD PERFORMANCE TRENDS IN PEDIATRICS AND CONGENITAL HEART DISEASE: WHAT STARTS UP, MUST COME DOWN

Abstract

Small children and certain types of congenital heart disease (CHD) require epicardial CIED systems when pacing is indicated. Lead performance at implant is potentially affected by patient clinical status, as many of these systems are placed during other operation for CHD or in the post-operative period. Anatomical alterations and scarring from prior procedures may result in limited options and higher lead performance measurements are often accepted at implant. To assess evolution of epicardial lead performance in the acute post-implant period at mid-term follow-up. Retrospective single center study of children and adult congenital heart disease patients undergoing epicardial bipolar pacing lead and generator implantation between 1/2012-6/2022. Patients were censored in follow-up at the time of lead removal, patient death, or pacing polarity change to unipolar. There were 256 leads implanted in 128 pts (mean age 6.1 ± 9.8 years), including 201 (79%) leads implanted in patients with CHD and 138 (54%) implanted in the perioperative or immediate post-operative period (within 30 days). Implant sites were: 76 right atrial, 71 right ventricle, 39 left atrial and 70 left ventricle. Threshold for measurements were available at 6 weeks and 1 year for 160 (63%) and 138 (54%) respectively. The mean threshold at time of implant was 1.3 (range 0.1-6) V. Mean threshold change from implant to post op day 1 (POD1), 6 weeks and 1 year was: –0.34±0.78V (p=0.0001), –0.23 ±0.85V (p=0.003), and –0.2±0.9V (p=0.0026), respectively. At implant, 47 leads (18%) had a threshold ≥ 2 V, of which 42/47 (90%) decreased to <2 by POD1. Leads with higher threshold at implant had a mean decrease in threshold by POD1 of -1.33 V vs. -0.44 V for leads with an implant threshold of <2V (p<0.0001). For patients with an implant threshold of ≥2V, impedance >1000 ohms, CHD, perioperative or acute post-op status, and location of the lead did not significantly impact the odds of having a persistently higher threshold (≥2 V) on POD1. Epicardial pacing lead thresholds improve significantly in the immediate post-op period, even when initial measures could be considered unacceptably high and remain stable at one year post implant. Most leads with high implant thresholds improved to <2 by POD1. No factors effecting the likelihood of improvement were identified. While striving for low threshold at implant remains important, these data support a high likelihood that thresholds will optimize by POD 1.