The Micra AV leadless pacing system demonstrated a 99.7% successful implantation rate, with early major complications occurring in 2.4% of patients and late pacemaker syndrome in 2.5%.
Cohort (n=1,003)
Yes
Does the Micra AV leadless pacing system demonstrate acceptable safety and clinical performance in patients requiring pacing in routine clinical practice?
The Micra AV leadless pacemaker demonstrates acceptable safety and performance in a high-risk real-world population, though atrioventricular synchrony declines at higher heart rates.
BACKGROUND: Evidence supporting the Micra AV leadless pacing system has largely derived from highly experienced centers, potentially limiting generalizability to routine clinical practice. METHODS: The AV-CESAR study is a nationwide retrospective cohort, including the first 1000 patients implanted with a Medtronic Micra AV leadless pacemaker in France (2020–2024). Mean follow-up was 13.4±10.6 months. Primary end points were early (in-hospital) and late (postdischarge) device-related major complications; pacemaker syndrome and need for implantation of a new pacing system were centrally adjudicated. RESULTS: Among 1003 patients, device implantation was successful in 1000 (99.7%). Mean age was 72.0±15 years; 62.8% were male, 44.0% had ≥2 comorbidities, and 62.4% were unsuitable for transvenous pacemakers. The primary indication was permanent complete atrioventricular block with preserved sinus rhythm (78.0%). Early major complications occurred in 2.4%, including pericardial effusion (0.8%; 3 requiring surgery), access-site complications (0.8%), and thromboembolism (0.3%). Late major complications included pacemaker syndrome (2.5%), pacing-induced cardiomyopathy (1.2%), high thresholds (>4 V/0.24ms, 0.3%), and premature battery depletion (0.2%). No device infections or dislodgements were observed. Overall, 2.5% of patients required implantation of a new pacing system (pacing-induced cardiomyopathy n=11; pacemaker syndrome n=7; high threshold n=3; battery/software failure n=3; tricuspid regurgitation n=1) and 12.7% were permanently reprogrammed to VVI mode. In pacing-dependent patients with ambulatory Holter monitoring (>3.4 million paced cycles), mean atrioventricular synchrony was 67.6±17.3% and correlated with device-reported AM-VP (74.8±17.1%; R 2 =0.92; P 90 beats per minute (5.6% of monitored time). All-cause mortality was 13.8%, with 0.2% directly device-related; 41.7% of deaths were cardiovascular. CONCLUSIONS: The Micra AV system is primarily used as an alternative when dual-chamber conventional pacemakers are not feasible. It demonstrated acceptable safety and clinical performance in a high-risk population. The marked reduction in atrioventricular synchrony at higher heart rates may suggest limited clinical benefit in patients with higher exertional heart rates. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT05953558.
Kerkouri et al. (Wed,) conducted a cohort in Permanent complete atrioventricular block with preserved sinus rhythm (n=1,003). Medtronic Micra AV leadless pacing system was evaluated on Early (in-hospital) and late (postdischarge) device-related major complications. The Micra AV leadless pacing system demonstrated a 99.7% successful implantation rate, with early major complications occurring in 2.4% of patients and late pacemaker syndrome in 2.5%.