Leadless Pacemaker Implantation in High-Risk Patients: Real-World Outcomes From a Multicenter Israeli Registry

Transvenous pacemakers are effective but carry significant short- and long-term complications. Leadless pacemakers were developed to overcome these limitations, however, data in high-risk patients ineligible for transvenous systems remain limited.

To evaluate the real-world outcomes of leadless pacemaker in high risk bradyarrhythmia patients unsuitable for transvenous pacing.

A retrospective, observational, multi center registry (MLPI) across four Israeli hospitals, included all patients undergoing leadless pacemaker implantation July 2021-December 2022 within a national pilot program. Indications included venous abnormalities, prior device infection, Twiddler's syndrome or high infection risk. Procedural success, complications, electrical performance, and mortality were assessed at 48 h, 30 days, and 12 months.

A total of 138 patients were enrolled, with a high comorbidity burden (hypertension 74%, heart failure 44%, chronic kidney disease 36%). High grade atrioventricular block was the main pacing indication (70%), and the leading reason for leadless implantation (54%) was high infection risk. Implantation was successful in 98% of the patients, almost all with Micra. Acute complications occurred in 2.9%, (primarily pericardial effusion); three patients (2.2%) died within 48 h. At 1-year, electrical performance remained stable, with low pacing thresholds (median 0.5 V), preserved sensing, and declining impedance. Two late complications occurred (tamponade, loss of capture). The 1-year cumulative complication rate was 4.7%, and all-cause mortality 12.3%.

Leadless pacemaker implantation in a very high-risk Israeli cohort achieved high procedural success, stable performance, and low complication rate, supporting its role as a safe and effective alternative to conventional pacing systems.