Preliminary results of the France LEADLESS study. A safety and effectiveness monitoring of a new ventricular leadless pacemaker

Leadless pacemakers (LP) have been recently developed to substitute transvenous pacemakers (TVP) when patients’ medical conditions prevent the use of TVP or suggest that TVP would be associated with high risk of lead- and pocket-related complications. LP may also improve patient safety and comfort by replacing surgery with a percutaneous procedure, eliminating the mass and scar visible at the TVP implantation site and eliminating the need for post-implant activity restrictions. A new ventricular (VR) LP system became available in 2023 in Europe; it features active fixation with helix, allows sensing/pacing parameters measures before LP fixation and it is upgradable to a dual chamber LP system.

To evaluate the safety and performance of a new VR LP system in a population of 400 all-comers patients indicated for implantation of a VVI(R) pacemaker.

French Cardiology Society is the sponsor of the France LEADLESS observational study which will involve all French sites implanting this new VR LP system. Patients will be followed for 2 years. We report preliminary analyses of clinical and electrical data collected at implant for 127 patients included between January 2024 and August 2024 at 16 French sites.

127 patients (36% female, mean age 74 years) have been so far included in the Registry. The most frequent patients’ comorbidities were hypertension in 75 (59%) patients and diabetes in 36 (27%) patients. The most frequent reported reasons to prefer a LP compared with TVP were high infectious risk in 53 (42%) patients, patient age in 37 (29%) patients, in particular in 16 (13%) young patients and in 21 (16%) old patients, limited venous access in 22 (17%) patients, previous infections in 16 (13%) patients, history of cancer in 13 (10%) patients, previous device/lead extraction in 13 (10%) patients, dialysis in 12 (9%) patients, patient choice in 9 (7%) patients, diabetes in 8 (6%) patients - taking into account that more than one reason could be associated to the same patient.

Most frequent LP implant positions were mid-septum in 66 (52 %) patients and apical septum in the 52 (41%). Mean skin-to-skin procedure time was 44±18 minutes. Mean fluoroscopic time was 9±8 minutes.

During implant the following complications occurred: pericardial effusion not requiring drainage in 1 (0.79%) patient, device dislodgement in 1 (0.79%) patient, fistula at femoral access in 1 (0.79%) patient treated with surgical intervention 6 days after. None of these events prevented successful implant.

At implant, mean R wave sensing was 8±3 mV, mean impedance was 817±432 Ohm, mean threshold was 0.9±0.6 V at 0.4 ms.

First real-world experience of a novel VR leadless pacemaker in France shows good safety profile, procedure times and electrical performances during implant. The most frequent reasons to choose a LP instead of a TVP were patients’ characteristics which predicted high infection risk.