Micra Transcatheter Pacing System Post-Approval Registry ClinicalTrials.gov identifier: NCT02536118; Micra Transcatheter Pacing Study ClinicalTrials.gov identifier: NCT02004873.

Aims Leadless pacing has emerged as an alternative to conventional transvenous pacemakers to mitigate the risks of pocket‐ and lead‐related complications but its use remains controversial in young adults mostly because experience in this patient population is limited. We sought to examine the feasibility and safety of implanting leadless single chamber pacemakers in young adults. Methods This multicenter, retrospective, observational study sought to evaluate the safety, efficacy, and electrical performance of the Micra VR Transcatheter Pacemaker System (Medtronic) in patients between 18 and 40 years who underwent implantation of a leadless pacemaker for any indication at the university medical centers of Bordeaux, Clermont‐Ferrand, Toulouse, and Tours (France), between 2015 and 2021. The primary safety endpoint was freedom from system‐related or procedure‐related major complications at 6 months. The primary efficacy endpoint was the combination of a low (≤2 V) and stable (increase within 1.5 V) pacing capture threshold at 6 months. Results Leadless pacemaker implantation was successful in all 35 patients. At 6 months, safety endpoint was met for 35 (100%) and efficacy endpoint for 34 (97%) patients. During a follow‐up of 26 ± 15 months (range: 6–60 months), Safety endpoint remained 100% and efficacy endpoint was 94%. Leadless pacemaker retrieval was not required in any patient. Approximately one‐third of patients (n = 13, 37%) had >40% ventricular pacing burdens at 1 year, including all 10 patients with a complete AV block but also 3 patients with normal AV conduction during implantation. One patient reported symptoms of pacemaker syndrome which was confirmed using Holter recording and successfully treated using reprogramming. Conclusion In this observational study, leadless pacemakers demonstrated favorable short‐ and intermediate‐term safety and effectiveness in young adults.

Introduction/Background By using an entirely extra-thoracic lead placement, subcutaneous implantable cardioverter–defibrillators (S-ICD) were designed to avoid lead-related complications of single-chamber transvenous implantable cardioverter-defibrillators (VVI ICD). Purpose Our objective was to assess and compare outcomes following first VVI ICD or S-ICD implantation in an exhaustive nationwide matched cohort. Methods This French longitudinal cohort study was based on the national hospitalization database covering hospital care from for the entire population. All adults (age ≥18 years) hospitalized in French hospitals From January 1, 2010 to September 1, 2020, who underwent a VVI ICD or S-ICD implantation were included. Patients with a previous pacemaker or ICD or with a history of infective endocarditis were excluded. Results 21,667 patients were included in the cohort, 19,493 patients had a transvenous VVI ICD and 2,174 had a subcutaneous ICD. Mean follow-up was 28.8±31.8 months. S-ICD patients was associated with higher rate of all-cause death (HR: 1.684, 95% CI: 1.309–2.165, p<0.001). There were no significant differences in cardiovascular death (HR: 1.092, 95% CI: 0.697–1.711, p=0.70) and infective endocarditis (HR: 0.354, 95% CI: 0.067–1.433, p=0.15) between the two groups Using propensity score, 1,582 patients with VVI ICD were matched 1:1 with S-ICD patients. Mean follow-up was 4.5±7.2 months. In the matched analysis, there were no significant differences in all-cause death (HR: 1.090, 95% CI: 0.728–1.633, p=0.68) and cardiovascular death (HR: 1.167, 95% CI: 0.603–2.260, p=0.65) between the two groups. A trend toward a lower risk of infective endocarditis in the S-ICD group was also observed without reaching significance (HR: 0.219, 95% CI: 0.047–1.017, p=0.053). A sensitivty analysis in patients with coronary artery disease in the matched cohort was performed. 1,024 patients had a VVI ICD and 977 had a S-ICD. Same trends were observed without significant differences in all-cause death (HR: 0.966, 95% CI: 0.605–1.543, p=0.88) and cardiovascular death (HR: 1.307, 95% CI: 0.610–2.799, p=0.49). Conclusion Our nationwide study highlighted a higher risk of all-cause death in patients treated with subcutaneous which however was not statistically significant after propensity score matching. No differences regarding cardiovascular mortality was found. An interesting trend toward diminution of infective endocarditis was also observed without reaching significancy. Funding Acknowledgement Type of funding sources: None. Baseline characteristicsCardiovascular death

Introduction/Background Leadless ventricular permanent pacemakers (leadless VVI, LPM) were designed to reduce lead-related complications of conventional VVI pacemakers (CPM). Purpose The aim of our study was to assess and compare real-life clinical outcomes within the first 30 days and during a mid-term follow-up with the two techniques at a nationwide level. Methods This French longitudinal cohort study was based on the national hospitalization database covering hospital care from for the entire population. All adults (age ≥18 years) hospitalized in French hospitals From January 1, 2017 to September 1, 2020, who underwent a first LPM or CPM implantation were included. Importantly, patients with dual chamber pacemaker were not included in our study. Results Of 42,315 patients included in the cohort, 40,828 patients (96%) had a CPM and 1,487 had a LPM. Using propensity score, 1,344 patients with CPM were adequately matched in a 1:1 fashion with LPM patients. Clinical outcomes at day 30 In the unmatched population, within the 30 days after implantation, patients with LPM had a lower rate of all-cause mortality (OR: 0.635, 95% CI: 0.527–0.765, p<0.0001) and from a cardiovascular cause (OR: 0.568, 95% CI: 0.405–0.797, p=0.001). They also had lower rates of major bleeding and need for transfusion. There was no significant difference between groups regarding tamponade, pneumothorax or hemothorax. In the matched population, LPM implantation was still significantly associated with a lower rate of all-cause death (OR: 0.583, 95% CI: 0.456–0.744, p<0.0001), cardiovascular death (OR: 0.413, 95% CI: 0.271–0.629, p<0.0001), major bleeding (OR: 0.523, 95% CI: 0.348–0.786, p=0.002) or transfusion (OR: 0.481, 95% CI: 0.296–0.780, p<0.0001). However, tamponade, pneumothorax or hemothorax were not significantly different between the two groups. Clinical outcomes during mid-term follow-up In the unmatched patients, mean follow-up was 8.6±10.5 months. Annual incidence of all-cause death was high in both groups, and significantly higher in the LPM group than in CPM group (31%/year vs. 20%/year, p<0.0001) with a HR of 1.519 (95% CI: 1.296–1.780). Cardiovascular death was not significantly different between groups. Infective endocarditis was higher in the LPM group than in the CPM group with a HR of 2.108 (95% CI: 1.119–3.973). In the matched patients, mean follow-up was 6.2±8.7 months. All-cause death, cardiovascular death and infective endocarditis were not significantly different between groups. Conclusion Mortality is high among unselected patients implanted with ventricular permanent pacemakers, whether leadless or conventional pacemaker are used. Implantation of leadless pacemakers seems to be a safe procedure in this high-risk population, with better outcomes at 1 month. Mid-term outcomes appear relatively similar in LPM and CPM patients. Funding Acknowledgement Type of funding sources: None. Central illustration