To retrieve, or not to retrieve: System revisions with the Micra transcatheter pacemaker

Background Early experience with leadless pacemakers has shown a low rate of complications. However, little is known about system revision in patients with these devices. Objective The purpose of this study was to describe the system revision experience with the Micra Transcatheter Pacing System (TPS). Methods Patients with implants from the Pre-market Micra Transcatheter Pacing Study and the Micra Transcatheter Pacing System Continued Access Study (N = 989) were analyzed and compared with 2667 patients with transvenous pacemakers (TVPs). Revisions included TPS retrieval/explant, repositioning, replacement, or electrical deactivation (with or without prior attempt at retrieval, generally followed by TVP implant) for any reason. Kaplan-Meier revision rates were calculated to account for varying follow-up duration and were compared using a Fine-Gray competing risk model. Results The actuarial rate for revision at 24 months postimplant was 1.4% for the TPS group (11 revisions in 10 patients), 75% (95% confidence interval 53%–87%; P Conclusion The overall system revision rate for patients with TPS at 24 months was 1.4%, 75% lower than that for patients with TVPs. TPS was disabled and left in situ in 64% of revisions, and percutaneous retrieval was successful as late as 14 months postimplant.