Background: Data on management of Micra Transcatheter Pacing System (TPS) during follow-up at the time of an upgrade or during battery depletion is limited.
Objective: We sought to evaluate the management patterns of patients implanted with a Micra TPS during long-term follow-up in our center
Methods: We retrospectively identified patients who underwent Micra implantation from April 2014 to October 2019 .We identified patients who underwent extraction (n=9) or had an abandoned system upgraded to a transvenous system or to a new Micra system (n=6).
Results: 295 patients received a Micra during the period of the study. Mean age was 74.1±14.5 years, 50.7% were men, and LVEF was 49.3±10.1 %. Indications for implantation included AV block (43.3%), sinus node dysfunction (35.3%), and other (21.4%). Mean follow up was 3.3±1.5 years. Procedural complications included pericardial tamponade (n=1) treated with pericardiocentesis, micro-dislodgement (n=4) treated with reimplantation (n=2), and any major groin complications (n=2) 9 patients underwent Micra extraction. Indications for extraction included upgrade to transvenous CRT device (n=4), bridging to transvenous device after lead extraction in pacemaker dependent patients (n=2), and high thresholds on existing Micra (n=3). The median time from implantation to extraction was 92.5 days, with the longest at 1442 days. In 8 out of 9 cases, a steerable sheath and a 20 mm snared were used while in one patient the Micra delivery system and a 7 mm snare was used. The average fluoroscopy time was 13.4±3.8 minutes. There were no procedural or long-term complications. In 6 patients the Micras were abandoned and turned off at the time of upgrade to a transvenous system. Four patients were upgraded to CRT and one to dual chamber pacemaker due to pacemaker syndrome . A new Micra TPS was implanted in a patient with a prior Micra and chronically elevated thresholds, which led to premature battery depletion.
Conclusion: In this large single center study, 5% of patients implanted with a Micra required a system modification over 5-year follow-up most commonly due to requirement for CRT pacing. These patients were managed successfully with an extraction or abandonment.