The Role of the Wearable Defibrillator in Heart Failure.

PURPOSE OF REVIEW: Wearable cardioverter defibrillators (WCDs) have been developed as a temporary measure for protecting patients at risk for sudden cardiac death that do not meet the indication for implantable cardioverter defibrillator (ICD), most notably in the early stages of heart failure with reduced ejection fraction before reassessment of their left ventricular ejection fraction. In this review, we report available evidence in the literature and guidelines regarding WCD use in order to try to define the role WCDs may have in heart failure. RECENT FINDINGS: In the last decade, most observational studies found WCDs to be both safe and effective in terminating ventricular arrhythmias in various indications, mostly centered around heart failure with reduced ejection fraction. The only available randomized controlled trial using WCD did not however show a benefit on patients' survival. Hence, recent guidelines only recommended its use in limited indications. Recent data also suggest a possible interest of WCD in monitoring patients, a finding that may prove useful in the context of new-onset heart failure. Data regarding WCD benefit is scarce, and definitive conclusions on its utility are hard to draw. In the context of heart failure, and particularly new-onset heart failure, WCD might find a role in a global comprehensive management of the disease, both acting as an educational tool, a monitoring tool, and, most importantly, a safe and effective tool in preventing sudden cardiac death. The low level of evidence however invites caution, and the decision of prescribing a WCD needs to be individualized and thoroughly discussed with the patient whose compliance is key with this device.

Comparison of first- and second-generation leadless pacemakers in patients with sinus rhythm and complete atrioventricular block.

INTRODUCTION: The efficacy and safety of leadless cardiac pacemakers (LPMs) as an alternative to conventional transvenous cardiac pacing have been largely reported. The first generation of the MicraTM transcatheter pacing system (VR; Medtronic) was able to provide single-chamber VVI(R) pacing mode only, with a potential risk of pacemaker syndrome in sinus rhythm patients. A second-generation system (AV) now provides atrioventricular synchrony through atrial mechanical (Am) sensing capability (VDD mode). OBJECTIVE: We sought to compare VR and AV systems in sinus rhythm patients with chronic ventricular pacing (Vp) for complete atrioventricular block. METHODS: All consecutive patients implanted with an LPM in our department for complete atrioventricular block were retrospectively screened. Patients with atrial fibrillation, sinus dysfunction, or Vp burden <20% at 1 month postimplantation were excluded. Patients were systematically followed with a visit at 1 month, and then at least once a year. RESULTS: A total of 93 patients-45 VR (2015-2020) and 48 AV (2020-2021)-were included. VR and AV patients had similar baseline characteristics, except for VR patients being older (80 ± 8 vs. 77 ± 9 years, p = 0.049). The mean Vp burden was 77% in the VR and 82% in the AV group (p = 0.38). In AV patients, the median AV synchronous beats rate was 78%, with 65% having a >66% rate. An E/A ratio <1.2 as measured on echocardiography was the only independent predictor of accurate atrial mechanical tracking (p = 0.01). One-year survival rate was similar in both groups. Five patients in the VR and 0 in the AV group eventually developed pacemaker syndrome within 1 year post-implantation (p = 0.02). CONCLUSION: In sinus rhythm patients with chronic Vp for complete atrioventricular block implanted with an LPM, the atrial mechanical sensing algorithm allowed significant atrioventricular synchrony in most patients and was associated with no occurrence of-otherwise rare-pacemaker syndrome.

Leadless cardiac pacing: Results from a large single-centre experience.

BACKGROUND: The efficacy and safety of leadless cardiac pacing as an alternative to conventional transvenous cardiac pacing in selected patients have been widely reported. AIM: To report the experience of a high-volume implantation centre with older and new generations of leadless pacemakers. METHODS: This retrospective observational study included the first consecutive 400 patients who underwent implantation of a leadless pacemaker in our centre. Complications and electrical parameters were evaluated during follow-up, comparing patients implanted with first-generation (Micra™ VR) and second-generation (Micra™ AV) leadless pacemakers (Medtronic, Minneapolis, MN, USA). Data were collected by a review of medical files. RESULTS: Among 400 procedures, there were 328 Micra™ VR pacemakers and 72 Micra™ AV pacemakers implanted, followed for a median of 16 months (694 patient-years). The mean age was 77 years and both groups had a high burden of co-morbidities. Implantation success rate was 99.5%. A total of 87.5% of patients were discharged the day after the procedure. The pacing threshold remained stable and<2V in 96.5% of all patients. The perioperative complication rate at 30 days was 3.5%. Outcomes were similar between the two groups. CONCLUSION: Leadless cardiac pacing is a safe and efficient alternative to conventional transvenous cardiac pacing.