Arrhythmias & electrophysiologyCohort study
One-Year Outcomes of the First 1000 Patients Implanted With the Medtronic Micra AV Leadless Pacing System in France: The AV-CESAR Cohort Study
- nationwide retrospective cohort
Authors' conclusion
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.
Study context
- Population
- First patients implanted with a Medtronic Micra AV leadless pacemaker in France (2020–2024)device implantation successful in 1000 (99.7%)
- Participants
- 1,003 patients
- Outcome
- Early (in-hospital) and late (postdischarge) device-related major complications
- Follow-up
- Mean 13.4±10.6 months
Main finding
As reported in the abstract
- Early major complications
- 2.4%
- Early: pericardial effusion (3 requiring surgery)
- 0.8%
- Early: access-site complications
- 0.8%
- Early: thromboembolism
- 0.3%
- Late: pacemaker syndrome
- 2.5%
- Late: pacing-induced cardiomyopathy
- 1.2%
- Late: high thresholds (>4 V/0.24ms)
- 0.3%
- Late: premature battery depletion
- 0.2%
Observational data: associations, not effects.
Further findings
Implantation of a new pacing system
- Required implantation of a new pacing system
- 2.5%
- pacing-induced cardiomyopathy
- n=11
- pacemaker syndrome
- n=7
- high threshold
- n=3
- battery/software failure
- n=3
- tricuspid regurgitation
- n=1
- Permanently reprogrammed to VVI mode
- 12.7%
Atrioventricular synchrony (pacing-dependent patients with ambulatory Holter monitoring, >3.4 million paced cycles)
- Mean atrioventricular synchrony
- 67.6±17.3%
- Device-reported AM-VP
- 74.8±17.1%
- Correlation R 2
- 0.92
- P
- P < 0.001
- Atrioventricular synchrony declined at heart rates >90 beats per minute (share of monitored time)
- 5.6%
All-cause mortality
- All-cause mortality
- 13.8%
- Directly device-related
- 0.2%
- Deaths that were cardiovascular
- 41.7%
Baseline characteristics
- Mean age
- 72.0±15 years
- Men
- 62.8%
- ≥2 comorbidities
- 44.0%
- Unsuitable for transvenous pacemakers
- 62.4%
- Primary indication: permanent complete atrioventricular block with preserved sinus rhythm
- 78.0%
Original publication
Summarised from the published abstract; every number is checked against it