Upgrading expandable leadless pacemakers from single- to dual-chamber.

Leadless pacemaker implantation in postpneumonectomy syndrome

Percutaneous solution for a frequent complication after transcatheter aortic valve replacement: A case of atrioventricular leadless pacemaker implantation after transcatheter aortic valve replacement

The AVEIR leadless pacemaker (LP) is a novel device that can function as a single atrial/ventricular or dual-chamber pacemaker. The introduction of single-chamber atrial LP has allowed electrophysiologists to treat patients with sinus node dysfunction with this device instead of implanting a dual-chamber transvenous pacemaker. We retrospectively identified all patients who underwent AVEIR LPs' implantation at Emory Healthcare between 2022 and 2025. Baseline characteristics, indications for pacing, and procedure outcomes were retrieved from electronic medical records. The device's electrical characteristics were reported from routine interrogations done at our device clinic. Between 2022 and 2025, 89 patients underwent implantation of 37 single-chamber atrial AVEIR, 34 single-chamber ventricular AVEIR, and 18 dual-chamber devices. Patients were followed for a median duration of 4.7 months [2;9]. The rate of major complications was 3.4% and minor complications 1.1%. Two patients with ventricular LP required upgrade to cardiac resynchronization therapy-defibrillator (CRT-D) due to pacing-induced cardiomyopathy (2.3%). One patient (2.7%) with a standalone atrial LP developed atrial fibrillation with slow ventricular response requiring the addition of a ventricular LP 10 months postimplantation. In our center, we adopted a modular pacing approach for leadless pacing. This strategy focuses on minimizing the amount of hardware in the heart. This reduces complications such as perforation and dislodgment while optimizing battery longevity, which is affected by i2i communication.

Background Leadless pacemaker has a low risk of complications such as infection, pneumothorax, and skin erosion, and it is good adaptation for elderly patients. While ventricular pacing induces ventricular desynchronization, and that is causes of heart failure. The aim of the present study, therefore, was to investigate the association between heart failure hospitalization and leadless pacemaker implantation. Methods Between September 2017 and January 2022, 929 consecutive patients were implanted pacemakers. The patients were divided according to types of pacemakers: leadless pacemaker (LPM group, n=368), and conventional pacemaker (PM group, n=561). The clinical outcome was heart failure hospitalization. Hospitalization was considered when patients presented with sign and symptoms consistent with heart failure and required intravenous therapy, and the indication of heart failure hospitalization was at the discretion of the physician. Follow-up visit was planned at 1, 3, 12, 24, and 36 months after pacemaker implantation. Clinical follow-up data were obtained from medical records and/or by telephone contact with the patients, families, or referring physicians. Results The median follow-up duration was 1.7 years (interquartile range 0.8-2.6 years). Hospitalization rate for heart failure in the LPM group was 9.3% at 1 year, 15.6% at 2 years, and 21.6% at 3 years, respectively. Adjusted heart failure hospitalization risk in the LPM group was significantly higher than the risk in the PM group (hazard ratio [HR] 1.70, 95% confidence interval [CI] 1.09-2.64, P=0.01). Patients with symptomatic bradycardia caused by sinus node dysfunction (SND) in the LPM group (n=150) were more admitted to the hospital for heart failure, compared with in the PM group (n=219) (HR 2.02, 95%CI 1.04-3.90, P=0.03), while no significant difference was observed between the two groups in the patients with bradycardia caused by atrial fibrillation (LPM group, n=71; PM group, n=18) or atrioventricular block (LPM group, n=147; PM group, n=324). Conclusions Hospitalization risk for heart failure was higher in patients with leadless pacemakers, compared with conventional pacemakers. The greater risk was mainly driven by older patients and patients with SND.

Funding AcknowledgementsType of funding sources: Private company. Main funding source(s): Medtronic, inc.IntroductionAdvances in leadless pacemaker technology have enabled accelerometer based atrioventricular synchronous (AVS) pacing by sensing atrial mechanical contraction. However, acute safety performance of these devices in real-world clinical practice has not been assessed.ObjectivesTo report the acute performance of the Micra AV transcatheter pacemaker from the worldwide Micra AV post-approval registry (PAR).MethodsThe Micra AV PAR is an ongoing prospective single-arm observational study designed to assess the safety and effectiveness of the Micra AV system in the real-world setting. Patients enrolled in the Micra AV PAR will be followed for 3 years. For the present interim analysis, baseline characteristics, total AV synchrony index (sum of %AM-VP, %AM-VS, and AV conduction mode switch percentage), and major complications occurring within 30-days of implant were summarized and compared to a historical cohort of 2,667 transvenous dual chamber (TV-DC) pacing patients.ResultsThe device was successfully implanted in 797 of 802 patients (99.4%) at 99 centers. Mean age was 74.1±15.1 years and 42.3% were female. The most common pacing indication was AV block (55.7%). Comorbidities included diabetes (29.7%), CAD (22.8%), and heart failure (12.1%), with 31.3% precluded from transvenous device therapy. Micra AV patients were on average older (74.1 vs. 71.1 yrs, P<0.0001) and had a significantly higher incidence of renal disease (22.3% vs. 9.8%, P<0.0001). Major complications occurred in 2.6% of Micra AV patients and in 7.1% TV-DC patients (P<0.001, Figure). The reduction in major complications was largely driven by the absence of pneumothoraces and lead dislodgements among Micra AV patients. Of the 309 patients programmed to VDD mode with at least 30 days of device follow-up, the median AV synchrony index was 86.0% (IQR: 69.2% - 97.2%). Mean A4 amplitude was 2.1±1.6 m/s2 post-implant and 2.2±1.7 m/s2 at follow-up (P=0.57) in 308 patients with paired assessments.ConclusionsThe Micra AV leadless pacemaker was implanted with a high rate of success in patients with a high co-morbidity burden, with a significantly lower rate of acute complications relative to dual-chamber transvenous pacemakers despite patients being older and having a higher incidence of renal disease. Longer-term performance will continue to be assessed in this ongoing trial.Major Complications Within 30-days

Background Leadless pacemakers are usually implanted as second line treatment in patients with increased risk for infection, difficult or obstructed vascular access, and other causes preventing an implantation of a traditional pacemaker. Data regarding the occurrence and need for leadless pacemaker extraction (LLPE) are currently absent and have not been compared to outcomes of transvenous pacemaker extraction (TLE). Moreover, leadless pacemaker implantation during TLE for active infection in being advocated without backing data. We aimed to assess the rate, causes and complications of device extraction in a large US national database. Methods Patients undergoing LLPE and TLE in the USA between 2016 and 2019 were identified from the National Inpatient Sample (NIS) database using ICD-10 codes. Clinical and sociodemographic data, in-hospital complications, outcomes and mortality were collected. Baseline characteristics and outcomes were compared between patients undergoing TLE and LLPE. Multivariate logistic regression identified predictors of in-hospital complications. Results An estimated total of 55,235 patients underwent an extraction procedure during the study period. 54,050 (97.8%) patients underwent TLE and 1,185 (2.1%) underwent LLPE. Patients who underwent LLPE were older, more likely females and had a higher comorbidity rate (Charlson-Deyo-Comorbidity-Index; 46% vs 39%, p&amp;lt;0.001). Etiology for LLPE was identified and reported only in 25.7% of cases, however infection causing extraction occurred in 11.4% of LLPE cases and 8% had LLPE due to device dysfunction. Main etiologies for TLE were infections (40.9%) and lead dysfunction (29.4%). In comparison to TLE, LLPE resulted in higher in-hospital mortality (7.2% vs. 3%, p&amp;lt;0.001) and vascular complications (2.5% vs. 1.0%, p&amp;lt;0.001). Multivariable analysis confirmed that LLPE was associated with more than double the risk of in-hospital mortality. Conclusion Extraction of leadless pacemakers due to infection is not rare. Patients undergoing LLPE have higher prevalence of vascular complications and in-hospital mortality in a US nationwide, all-comer registry.

B-PO03-041 CORRELATION OF EF AND >99% PACING IN PATIENTS WITH LEADLESS PACEMAKERS

Background A leadless pacemaker (L-PM) has been designed to avoid the need for a pacemaker pocket and transvenous lead. Long-term safety will largely depend on the need for replacements, mainly due to battery depletion (end-of-life). While the mean L-PM battery longevity predicted by the manufacturer is 12 years, real-world longevity data are still scarce. We aimed to describe L-PM parameters’ stability and battery longevity during the mid-term follow-up. Methods Single-center registry of consecutive patients undergoing L-PM implantation from May 2015 to November 2023. Procedural characteristics, lead parameters and battery longevity were collected immediately after implantation and during the most recent follow-up visit. Results Overall, 261 consecutive patients had a transcatheter L-PM implanted through a femoral vein (mean age 78±10 years; 66% male). Mean procedural duration was 44±28min and fluoroscopy time was 4,4±3,9min. The device was successfully implanted in all but one patient. The main indications for permanent pacing were high-degree atrioventricular block [N=130 (50%)], atrial fibrillation with pauses [N=78 (30%)], and sinus node disease [N=28 (11%)]. Immediately after implantation, three cases (1,2%) of pericardial effusion (one with tamponade) were reported. In one case (0,4%), a conventional pacemaker was implanted due to L-PM acute dysfunction. No other procedure-related complications, including dislodgment, were reported at discharge. After a mean follow-up of 2,8±1,7years, the pacing threshold and R-wave amplitude remained stable [0,67mV vs. 0,62mV (p=0,9); and 10,3mV vs. 16,1mV (p&amp;lt;0,001), respectively] and mean ventricular pacing was 54±38%. Expected battery longevity was &amp;gt;8 years (maximum value) in 84% of the patients. In the subgroup of patients with &amp;gt;5 years of follow-up (N=20; mean follow up of 6,3±1,8years), the expected battery longevity was &amp;gt;8 years in 85% (N=17) of the patients. In three cases, the L-PM was upgraded to cardiac resynchronization therapy or left bundle branch area pacing due to pacing-induced left ventricular dysfunction. There was one case of L-PM end-of-life 6 years after implant (pacing threshold 0,5mV; ventricular pacing 100%), in which a second L-PM was successfully implanted. Overall, 78 (31%) patients died, a mean of 2,2±1,9 years after L-PM implantation, none related to the device. Conclusion In this real-world cohort, L-PM maintained stable pacing parameters and, in the mid-term follow-up, only one battery depletion was observed while expected longevity remained above 8 years in the large majority of patients. Longer follow up will allow better understanding of both technical and clinical aspects relevant to manage end-of-life devices.Table 1Figure 1

Leadless pacemakers (L-PM) are an emerging effective and safe technology that offer an alternative to conventional pacemakers (C-PM) for right ventricular stimulation. However, there is little information about their potential benefits for quality of life (QoL) in patients with L-PM. We compared QoL between patients with L-PM and C-PM. The study population comprised patients undergoing single chamber pacemaker implantation from December 2016 to March 2018. The SF-36 questionnaire was used to evaluate QoL at baseline and at 6 months of followup. We also used a questionnaire consisted of 10 specific questions related to the implant procedure. A total of 106 patients (64 C-PM; 42 L-PM) were included. There were no differences in baseline characteristics between the groups (C-PM vs L-PM), except for age (81.5 vs 77.3 years; P = .012) and diabetes (38% vs 17%; P = .021). Baseline SF-36 scores did not differ between the groups. At 6 months followup, patients in the L-PM group scored significantly higher on physical function (63 vs 42; P < .001), physical role (64 vs 36; P = .004), and mental health (75 vs 65; P = .017), even after adjusting for covariates. Pacemaker-related discomfort and physical restrictions were significantly lower for the L-PM group. L-PM is associated with better QoL than C-PM in both physical and mental health. Patients undergoing L-PM implantation reported less procedure-related discomfort, physical restriction, and preoccupation.

Leadless pacemakers (LPs) can mitigate conventional pacemaker complications related to the transvenous leads and subcutaneous pocket surrounding the pulse generator. Although single-chamber leadless pacing has been established, multichamber pacing requires wireless bidirectional communication across multiple LPs to maintain synchrony. This preclinical study demonstrates the chronic performance of implant-to-implant (i2i) communication that achieves synchronous, dual-chamber pacing with 2 LPs. The i2i communication modality employs subthreshold electrical signals conducted between implanted LPs through the blood and myocardial tissue on a beat-by-beat basis. Right atrial and right ventricular LPs were implanted in 9 ovine subjects. The i2i transmission performance was evaluated 13 weeks after implant. Right atrial and right ventricular LPs were implanted successfully and without complication in 9 ovine subjects. A total of 8715±457 right atrial-to-right ventricular and right ventricular-to-right atrial transmissions were sent per hour, with a success rate of 99.2±0.9%. Of periods with i2i communication failure when DDD pacing was not possible, 97.3±1.8% were resolved within 6 s. For the first time, synchronized, dual-chamber pacing has been demonstrated in a chronic preclinical feasibility study by 2 leadless pacemakers using beat-to-beat, wireless communication, achieving a success rate of 99.2%.

IntroductionThe long‐term performance of leadless pacemaker (LPM) has not been well evaluated.MethodsBetween September 2017 and January 2021, 929 consecutive patients who underwent pacemaker implantation were grouped according to the types of pacemakers: LPM (LPM group, n = 368) and conventional pacemaker (PM group, n = 561).ResultsThe median follow‐up duration was 1.7 years (interquartile range 0.8–2.6 years). Hospitalization rate for heart failure in the LPM group was 9.3%, 15.6%, and 21.6% at 1, 2, 3 years, respectively. The LPM group had a significantly higher adjusted heart failure hospitalization risk than the PM group [hazard ratio (HR) 1.70, 95% confidence interval (CI) 1.09–2.64, p = .01]. More patients with symptomatic bradycardia caused by sinus node dysfunction (SND) in the LPM group (n = 150) were admitted to the hospital for heart failure compared to those in the PM group (n = 219) (HR 2.02, 95%CI 1.04–3.90, p = .03), whereas no significant difference was observed between the two groups in the patients with bradycardia caused by atrial fibrillation (LPM group, n = 71; PM group, n = 18) or atrioventricular block (LPM group, n = 147; PM group, n = 324).ConclusionsPatients who received LPM implantation had greater hospitalization risk for heart failure, compared to those who received conventional pacemaker implantation. The increased risk was mainly attributed to patients with SND.

Introduction: Some studies suggested gender differences in procedural complication rates and long-term outcomes for trans-venous pacemakers. Little is known about gender differences associated with leadless pacemaker (LP) implantation. Methods: We reviewed all Medtronic Micra LP implants at our institution from 9/2014 to 9/2022. Device parameters (R wave sensing, impedance, and capture threshold), right ventricular pacing burden (RVP), left ventricular ejection fraction (LVEF), and 30-day adverse events post implant were obtained. Results: Among 489 patients, 50.9% were men. Mean follow-up was 1.7 ± 1.5 years. Women were older than men at the time of LP implant (78.1 ± 14.7 vs 75.5 ± 15.3 years old, p=0.04). There were no significant differences in R wave sensing and RVP between genders. Impedance and LVEF were higher in women and capture thresholds were higher in men at both baseline and last follow up. Despite significant differences in device parameters between genders, differences were small and not clinically relevant in most cases (Figure). Mean number of device deployments required at implant was similar: women 1.3 ± 0.6 vs men 1.4 ± 0.9, p=0.16). Implant related complications were similar between women and men: access site hematoma (5 vs 9, p=0.42), pseudoaneurysm (0 vs 2, p=0.49), cardiac perforation (2 vs 1, p=0.62), 30-day re-hospitalization (16 vs 25, p=0.19) and 30-day mortality (16 vs 17, p=0.99). LVEF decreased over time in both genders (Figure). During follow-up, 4 women and 6 men required transvenous cardiac resynchronization therapy (CRT) implantation (p=0.75) and 4 women vs 2 men required transvenous dual chamber pacemaker implantation (p=0.44). Conclusion: Outcomes of leadless pacemaker implantation are similar between women and men. Long-term device function is excellent in both genders. However, about 3% of all patients required device upgrade, highlighting the need for close electrophysiology follow-up after LP implant in both genders.

Efficacy and safety of leadless pacemaker: A systematic review, pooled analysis and meta-analysis

Background While the Medtronic Micra pacemaker provided a small device for leadless pacemaker implantation, the Aveir device allows chronic retrievability and mapping prior to fixation. We present the first Aveir leadless pacemaker implantations in a pediatric population. Purpose To describe the first retrievable leadless pacemaker implants in children. Methods Retrospective review of pediatric Aveir implants occurred between November 2022 and December 2022. All patients were implanted via internal jugular vein insertion utilizing the Aveir sheath and catheter deployment system with mid-atrial approach taken prior to insertion of the catheter across the tricuspid valve. All patients had initial mapping of capture threshold, impedance and R-wave noted prior to deployment. Indications for pacing included sinus pauses and intermittent atrioventricular block. Results Three patients underwent Aveir leadless pacemaker implantation with weights of 32.3kg, 44kg, and 51kg. Capture thresholds were all 0.75Volts@0.2 milliseconds with impedance range of 370-1110 ohms, and R-waves of 8-14 millivolts (mV). Follow-up at 3 months ranged from 0.5V@0.2ms to 1V@0.2ms with impedances ranging 400-700 ohms, and R-wave 7-14 mV. At VVI 50-55bpm, with pacing ranged from 5% to 14%, predicted longevities ranged from 20 to 24.5 years at 3 months follow-up. Conclusion(s) Retrievable leadless pacemaker implantation is feasible in children and may offer good longevities for intermittent pacing need.Aveir Leadless Pacemaker in RVAveir Leadless Pacemaker in RV

Funding AcknowledgementsType of funding sources: None.Backgroundtransvenous (TV) pacemakers are negatively associated with local and systemic device-related infections, often requiring transvenous lead extraction (TLE). Moreover, patients reimplanted with a TV device following TLE, exhibit substantial mortality and reinfection rates during the subsequent follow-up (FU). In this setting, leadless pacemakers (LPMs) are appealing as a first choice for TLE patients requiring a pacemaker reimplantation. To date, limited data on real-world safety and efficacy of LPMs in patients who underwent TLE are available.PurposeThe present study aims to assess long-term safety and efficacy of LPM implantation in patients who previously underwent TLE of a transvenous pacemaker, compared to LPM de novo implant patients.MethodsConsecutive patients who underwent LPM implantation in 12 centers joining the International LEAdless PacemakEr (i-LEAPER) registry were enrolled. Patients receiving LPM following TLE (n=184) were compared with patients with de novo implant (n=995). The primary endpoint was LPM-related major complications rate at implant and during FU. Additionally, differences in electrical performance were assessed between the two groups. Completion of 12-months FU was obtained in all patients.Results1179 patients were enrolled in this study and followed for a median of 12 [IQR 11-14] months. Baseline clinical characteristics resulted balanced among the two groups, apart from a higher prevalence of heart failure among recipients of LPM following TLE (16.8% vs. 9.4%, p=0.013). As reported in the Table, LPM related major complications and all-cause mortality did not differ among the two groups (1.6% TLE group vs. 2.2% de novo group, p=0.785, and 5.4% TLE group vs. 7.8% de novo group, p=0.288, respectively). Pacing threshold (PT) resulted higher in the TLE group throughout the FU (Figure-Panel A). Higher PTs were recorded in LPMs implanted at same location from where the previous transvenous lead was removed, as far as 12-months postimplant (Figure-Panel B), with a higher proportion of patients with high PT (>1 to 2V @0.24ms) in the first group at implant, 1-month, and 12-month FU (Figure-Panel C).ConclusionIn this real-world registry, LPMs showed a satisfactory safety and efficacy profile after TLE. In the post-TLE cohort, better electrical parameters were obtained when LPMs were implanted at a different location from where the previous transvenous lead was extracted.TABLEFIGURE