Safety profile of a ventricular leadless pacemaker. Data from 1265 patients in the France LEADLESS study

Background Leadless pacemakers (LP) are recommended for patients in whom transvenous pacemakers (TVP) are contraindicated or associated with a high risk of lead- or pocket-related complications. In 2023, a new ventricular (VR) LP system became available in Europe. Compared with previous LP devices, this system incorporates a helix fixation mechanism and advanced electrical mapping capabilities, designed to enhance implant safety. Objective To evaluate the safety profile of this new VR LP system in routine clinical practice through a nationwide observational registry. Methods The France LEADLESS observational study, sponsored by the French Cardiac Society, enrolls all-comer patients indicated for implantation of the new VR LP system across 39 French centers. Patients are followed for 3 years. We report procedural success and in-hospital complications for 1,265 patients implanted between January 2024 and October 2025. Results Implant was attempted in 1,265 patients (35% female; mean age 74 years). The primary pacing indication was AV block (59.2%) and patients characteristics were comparable to those of standard TVP cohorts; hypertension (63,8%) and diabetes (27,5%) were the most frequent patients’ comorbidities. Procedural success was achieved in 1,254 patients (99.0%). No procedure- or device-related death occurred before discharge. Overall, acute and in-hospital complications up to day 3 were reported in 23/1265 patients (1,8%). Two device dislodgements occurred (migration to the inferior vena cava and the pulmonary artery), both successfully managed by retrieval and repositioning. Seven cases of tamponade or pericardial effusion were observed; six were treated by pericardiocentesis and one required surgical repair with sternotomy. No thrombosis or embolic events were reported. Number and incidence rate of specific complications are described in the table. Conclusion In this large, nationwide cohort of all-comer French patients implanted with a new VR leadless pacemaker during the first 20 months post-market release, the device demonstrated a high procedural success rate and a favorable safety profile.