Implantation of leadless pacemakers via inferior vena cava filters is feasible and safe: Insights from a multicenter experience

Background: The leadless Micra transcatheter-pacing system (Micra-TPS) is implanted via a femoral approach using a 27-French introducer sheath. The Micra Transcutaneous Pacing Study excluded patients with inferior vena cava (IVC) filters. Objective: To examine the feasibility and safety of Micra-TPS implantation through an IVC filter. Methods: This multicenter retrospective study included patients with an IVC filter who underwent a Micra-TPS implantation. Data for clinical and IVC filter characteristics, preprocedure imaging, and procedural interventions were collected. The primary outcome was a successful leadless pacemaker (LP) implantation via a femoral approach in the presence of an IVC filter. Periprocedural and delayed clinical complications were also evaluated. Results: Of the 1528 Micra-TPS implants attempted, 23 patients (1.5%) had IVC filters. The majority (69.6%) of IVC filters were permanent. Six (26.1%) patients underwent preprocedural imaging to assess for filter patency. One patient's filter was retrieved before LP implantation. The primary outcome was achieved in 21 of 22 patients (95.5%) with an existing IVC filter. An occluded IVC precluded LP implantation in one patient. Difficulty advancing the stiff guidewire or the 27-Fr sheath was encountered in five patients. These cases required repositioning of the wire (n = 2), gradual sheath upsizing (n = 2), or balloon dilation of the filter (n = 1). Postprocedure fluoroscopy revealed intact filters in all cases. During a median 6-month follow-up, there were no clinical complications related to the filter or the Micra-TPS. Conclusion: This multicenter experience demonstrates the feasibility and safety of Micra-TPS implantation via an IVC filter without acute procedural or delayed clinical complications.