Smaller hardware when the smallest patients need pacing: early multicenter experience from the NeoPACE Study
P Ferrari, G Malanchini, D A Garattini, C Leidi, V Bhole, C M Go-Cacanindin, K Charalampos, C Vo, S Sanatani, L Tomasi, F J Papesso, P De FilippoAbstract
Background
Permanent pacing in neonates presents substantial challenge due to extremely small body size, anatomic variability and limited device options; even the smallest conventional pacemakers remain disproportionally large for newborns < 3 kg. To overcome these limitations, a novel pediatric-sized implantable pulse generator, derived from a modified leadless pacemaker subassembly and connected to bipolar epicardial leads, has been introduced. Evidence for its clinical use in this population is still limited. We here propose the first report from its international use.
Methods
NeoPACE study is a multicenter observational registry collecting real-world data on neonates requiring permanent pacing and implanted with the new Implantable Pulse Generator device. Eleven consecutive patients were enrolled across seven international centres between March 2023 and October 2025. Demographic data (mean gestational age 33.9 ± 3.0 weeks, mean weight 1901.8 ± 564.3 g), clinical history and procedural details were collected. Follow-up was available for all patients, with a median duration of 8.1 months (IQR 3.0–13.1, 1 - 22.7 months).
Results
The main indication for pacing was congenital AV block (10 patients, 90.9%, including 5 cases attributed to maternal circulating antibodies for autoimmune disease), one patient had severe sinus node dysfunction (9.1%). Every patient received a single chamber epicardial system with ventricular lead. Mean body weight at time of implant was 1901,8 ± 564,3 g. Procedural success was achieved in all cases. Median age at implantation was 40 days (0 - 95 days), including one newborn implanted at birth. Mean procedure time was 106.6 ± 44.9 minutes. At implantat, mean capture threshold was 0.75±0.50 V x 0.40 ms, R-wave amplitude 10.1±5.2 mV, and impedance 785.5±328.7 Ω. Electrical performance remained stable during follow-up. No acute complications or procedure-related mortality occurred. Adverse events were reported in 2 patients (18.2%), both related to epicardial lead dysfunction. Two required surgical revision (at 5 and 15 months). In 2 other patients, a progressive increase in capture threshold up to 1.88 V x 0.4 ms was observed. One was successfully managed by device reprogramming; while the other underwent battery replacement 10 months after implant. All patients remained on VVI pacing (10 at 110 bpm, 1 at 80 bpm, 1 at 70 bpm as lower rate), with 99-100% ventricular pacing in 9 cases (81.8%). All patients demonstrated appropriate growth and device tolerance during follow-up. No skin erosions or pocket infections was observed.
Conclusions
In this multicenter experience, implantation of the novel implantable pulse generator was feasible and acutely safe. Mid-term performance was stable. These early results confirm feasibility of the use of the device and underscore need for continued long term evaluation and device refinement, specifically tailored to this highly vulnerable population.