one-year outcomes of the first 1000 patients implanted with th micra AV leadless pacing system in france: the AV-CESAR cohort study

Abstract Background Evidence supporting the Medtronic Micra AV leadless pacing system has largely come from industry-sponsored studies and highly experienced centers, which may introduce bias into its overall evaluation. Purpose The AV-CESAR study aimed to evaluate the Micra AV leadless pacing system in a nationwide, real-world cohort in France. Methods This retrospective study enrolled the first 1000 patients implanted with a Medtronic Micra AV leadless pacemaker in France between 2020 and 2024. The mean follow-up duration was 13.4±10.6 months. The primary endpoints were early (in-hospital) and late (post-discharge) device-related major complications, focusing on pacemaker syndrome and device revision (need for a new pacing system). Results Out of 1003 patients, the device was successfully implanted in 1000 (99.7%). Mean age was 72.0±15 years, 62.8% male, 44.0% with ≥2 comorbidities, and 51.0% were considered unsuitable for transvenous pacemaker. The primary indication for pacing was permanent complete atrioventricular block with preserved sinus node function in 78.0%. Early major complications occurred in 24 patients (2.4%), including 8 cases (0.8%) of pericardial effusion (3 of which required cardiac surgery), femoral access site complications (0.8%), and thrombosis/embolism (0.3%), with two device-related deaths (0.2%) overall. Late major complications occurred in 40 patients (4.0%), including pacemaker syndrome (2.5%), pacing-induced cardiomyopathy (1.2%), and premature battery depletion (0.2%). No Micra device infections or dislodgement were reported. Overall, 2.5% of patients required device revision, and 12.7% of devices were permanently programmed to VVI(R) mode. Conclusion Despite inconsistent AV synchrony, the Micra AV system demonstrated reasonable safety and efficacy, making it a viable alternative for patients unsuitable for transvenous pacing.