Okabe, Toshimasa

AbstractBackgroundThe 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.ObjectiveTo examine the feasibility and safety of Micra‐TPS implantation through an IVC filter.MethodsThis 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.ResultsOf 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.ConclusionThis multicenter experience demonstrates the feasibility and safety of Micra‐TPS implantation via an IVC filter without acute procedural or delayed clinical complications.

AbstractBackgroundAn internal risk stratification algorithm was developed to decrease the risk of major adverse cardiac events (MACEs) during lead extractions (LEs).ObjectiveTo report upon the impact of a risk stratification algorithm (RISE [RIsk Stratification prior to lead Extraction] protocol) on outcomes of LEs in a high‐volume center.MethodsA retrospective review of a prospectively maintained LEs database was performed to identify features associated with MACEs. On the basis of the retrospective data, the RISE protocol differentiated LEs procedures into “High” and “Low” risk for occurrence of MACEs. High‐risk LEs included dual‐coil defibrillator lead (≥3 years), pacemaker and single‐coil lead (≥5 years), and any StarFix coronary sinus lead. During the prospective evaluation of the RISE protocol, “High‐risk” LEs were performed in an operating room (OR) or hybrid laboratory with the cardiac anesthesiologist, OR nursing team, perfusionist in the room, and a cardiac surgeon on the premises. “Low‐risk” LEs were performed in the electrophysiology (EP) laboratory with anesthesia provided by EP nursing team. The preintervention (pre‐RISE) and postintervention (post‐RISE) group spanned 19 and 40 months and consisted of 449 (632 leads) and 751 patients (1055 leads), respectively. The primary outcome of MACEs in the two groups was compared.ResultsProtocol compliance was 100%. The primary outcome of MACEs occurred in 15 patients (3.34%) before and 12 (1.6%) after implementation of the RISE protocol (P = .04).ConclusionRISE identified a low‐risk group where minimal resources are needed and allowed for rapid intervention in the high‐risk group that reduced the consequences of MACEs.

AbstractBackgroundThe Micra clinical trials have enrolled more than 2500 patients without any reported device‐related infections that required removal during follow‐up. Leadless pacemakers might be more resistant to bacterial seeding due to smaller surface area and a greater tendency for encapsulation.ObjectiveTo analyze the incidence and outcomes of serious infectious events (SIEs: bacteremia or endocarditis) that developed during follow‐up in patients with history of Micra leadless pacemaker implantation.MethodsSIE and outcomes were characterized based upon adverse event reports. Among 720 patients implanted with Micra in the investigational device exemption trial, we identified 16 patients who had documented 21 SIEs during follow‐up.ResultsAmong patients with SIEs, mean age was 71.9 ± 11.7 years. SIEs occurred at a mean 4.8 ± 4.5 months after implant and patients were followed for 13.1 ± 9.1 months after documentation of SIE. All events were adjudicated as unrelated to the Micra device or procedure. Bacteremia was documented to be related to a gram‐positive organism in 13 events (seven Staphylococcus, three Streptococcus, two Enterococcus, and one uncharacterized gram‐positive bacteria), and gram‐negative organisms in three events. In five events, the type of organism was not characterized (two patients with endocarditis). No persistent cases of bacteremia after antibiotic cessation were seen over the duration of follow‐upConclusionIn this small series of Micra patients who developed SIEs postimplant, the occurrence of bacteremia and/or endocarditis did not appear to lead to persistent bacteremia off antibiotics; most events resolved with antibiotic treatment.