Mp-453087-3 removal of a chronically-implanted micra leadless ventricular – single center experience

Leadless cardiac pacemakers (LPs) are an effective and safe alternative to transvenous pacemakers for single-chamber ventricular pacing. However, the feasibility of retrieving and replacing chronically implanted LPs is not well understood. We report an unique single center series of chronically implanted MICRA TPS™ leadless pacemakers. Since 2014 there were 227 MICRA LP devices implanted successfully to the right ventricle (RV) position. In 8 patients with average time of 685 ± 373 days retrieval procedure was indicated. The main indication for LP extraction was: a) pacemaker syndrome; b) battery depletion (in two patients together with WiSE EBR left ventricle (LV) co-implant); c) needs to upgrade VVI pacing for resynchronization therapy with LV systolic dysfunction. In all 8 patients we used MICRA delivery catheter with single loop 7 mm snare inserted into the central lumen of the original delivery catheter. Besides fluoroscopy we guided the retrieval procedure with intracardiac echocardiography (ICE). The retrieval procedure was successful in 7 out of 8 petients (87,5%). Average time of the index retrieval procedure was 118 ± 27 minutes and average fluoroscopy time was 26.6 ± 10.5 minutes. In the case with retrieval procedure failure (348 days after implant) we couldn’t snare the docking bottom of the device. In rest of the cases where we were able to snare it and connect with the delivery catheter cap, we were able to reach the insertion of the LP to the tissue and apply contratraction force with 100% success. When we analysed ICE images, the LP retrieval failure was associated with massive tissue overgrow around the device capsule. In 6 patients new MICRA TPS™ LP was implanted with excellent pacing parameters and optimal sensing and impedance during the same procedure. In one patient we implanted CRT-D transvenous system due to LV dysfunction. This series demonstrates the feasibility of retrieval of even long-term chronically-implanted MICRA LPs. The dedicated retrieval system for LPs with anchors will be of interest when we can consider needs to exchange of LPs specifically in younger patients.