METHODS AND RESULTS: The primary outcome (risk of cardiac failure, pacemaker syndrome, or syncope related to the Micra system or procedure) was compared between successfully implanted patients from the Micra IDE trial with a primary pacing indication associated with AF or history of AF (AF group) and those without (non-AF group). Among 720 patients successfully implanted with Micra, 228 (31.7%) were in the non-AF group. Reasons for selecting VVI pacing in non-AF patients included an expectation for infrequent pacing (66.2%) and advanced age (27.2%). More patients in the non-AF group had a condition that precluded the use of a transvenous pacemaker (9.6% vs. 4.7%, P = 0.013). Atrial fibrillation patients programmed to VVI received significantly more ventricular pacing compared to non-AF patients (median 67.8% vs. 12.6%; P
OBJECTIVE: The purpose of this study was to report the worldwide experience with successful retrieval of the Micra TPS.
METHODS: A list of all successful retrievals of the currently available leadless pacemakers (LPs) was obtained from the manufacturer of Micra TPS. Pertinent details of retrieval, such as indication, days postimplantation, equipment used, complications, and postretrieval management, were obtained from the database collected by the manufacturer. Other procedural details were obtained directly from the operators at each participating site.
RESULTS: Data from the manufacturer consisted of 40 successful retrievals of the Micra TPS. Operators for 29 retrievals (73%) provided the consent and procedural details. Of the 29 retrievals, 11 patients underwent retrieval during the initial procedure (immediate retrieval); the other 18 patients underwent retrieval during a separate procedure (delayed retrieval). Median duration before delayed retrieval was 46 days (range 1-95 days). The most common reason for immediate retrieval was elevated pacing threshold after tether removal. The most common reasons for delayed retrieval included elevated pacing threshold at follow-up, endovascular infection, and need for transvenous device. Mean procedure duration was 63.11 ± 56 minutes. All retrievals involved snaring via a Micra TPS delivery catheter or steerable sheath. No serious complications occurred during the reported retrievals.
CONCLUSION: Early retrieval of the Micra TPS is feasible and safe.