BACKGROUND: Aveir DR (Abbott, Abbott Park, IL) is a dual-chamber leadless pacemaker (LP) system with distinct atrial and ventricular LPs (ALP, VLP) that communicate wirelessly to deliver atrioventricular synchronous pacing. Success rates of these implant-to-implant (i2i) transmissions have not been systematically evaluated. OBJECTIVE: This study aims to evaluate chronic i2i success rates in a clinical setting. METHODS: Patients meeting standard dual-chamber pacing indications were enrolled and implanted with dual-chamber LP systems as part of a prospective international clinical trial (Aveir DR i2i Study). The percent of successful i2i transmissions from ALP-to-VLP (A-to-V) and VLP-to-ALP (V-to-A) were interrogated from LPs in de novo patients using the device programmer at implant, discharge, and at 1, 3, and 6 months postimplant (1M, 3M, 6M). RESULTS: A total of 399 patients completed device implant and i2i diagnostic interrogation (62% male; age 69 years; 65% sinus node dysfunction, 32% atrioventricular [AV] block). Median A-to-V and V-to-A i2i success rates exceeded 90% of beats at all time-points from implant to 6M. The minority of patients with A-to-V or V-to-A i2i success in <70% of beats at implant (A-to-V: 19% of patients, V-to-A: 31% of patients) showed roughly 40% improvement by 1M, with this minority dropping to roughly 5% of patients by 6M. Improvement in i2i communication success may be attributed to reprogramming of i2i setting levels, natural changes in dominant posture, and device stabilization. CONCLUSION: Wireless implant-to-implant communication in the new dual-chamber leadless pacemaker system demonstrated successful transmissions in >90% of beats throughout the 6-month evaluation period. Communication success improved significantly over time postimplant for specific subgroups. CLINICAL TRIAL REGISTRATION: Aveir DR i2i Study, ClinicalTrials.gov ID NCT05252702.

• MeSH
• Wireless Technology MeSH
• Equipment Design * MeSH
• Cardiac Pacing, Artificial methods   MeSH
• Pacemaker, Artificial * MeSH
• Middle Aged MeSH
• Humans MeSH
• Follow-Up Studies MeSH
• Prospective Studies MeSH
• Aged MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH

AIMS: A dual-chamber leadless pacemaker (LP) system that employs distinct atrial and ventricular LP devices (ALP, VLP) has been introduced to clinical practice. Proprietary, low-energy, implant-to-implant (i2i) communication at each beat enables the devices to maintain synchronous atrioventricular sensing and pacing. We evaluated device longevities and contributing factors, such as i2i communication. METHODS AND RESULTS: Patients meeting dual-chamber pacing indications received the dual-chamber LP system as part of a prospective, multi-centre, international clinical trial (Aveir DR i2i Study, NCT05252702). Programming and diagnostics were interrogated from all de novo, non-revised, dual-chamber programmed devices at 12 months post-implant. This analysis included 302 patients (65% male; age 70 ± 13 years; weight 80 ± 19 kg; intrinsic heart rate 55 ± 7 bpm; 58% sinus node dysfunction, 27% atrioventricular block). At 12 months, devices were programmed to dual-chamber pacing (DDD(R) or DDI(R)) at a median 60 bpm rate, median 1.25 V pulse amplitude in ALP and 1.5 V in VLP, median 0.4 ms pulse width, and median i2i signal setting level 5 out of 7. Median ALP and VLP remaining battery longevities at 12 months were 4.3 and 9.1 years, with median total ALP and VLP longevities of 5.3 and 9.9 years. Base rate, pulse amplitude, pacing percentage, event rate, impedance, and i2i setting level all exhibited significant correlations with ALP and VLP longevities (P < 0.001). Programming i2i setting levels below 7 produced the greatest longevity savings. CONCLUSION: The first dual-chamber LP demonstrated adequate projected battery longevity after 12 months of use. Patient-specific device programming considerations, unique to leadless devices, may extend longevity.

• MeSH
• Atrioventricular Block therapy   diagnosis   physiopathology   MeSH
• Time Factors MeSH
• Equipment Design MeSH
• Cardiac Pacing, Artificial * methods   MeSH
• Pacemaker, Artificial * MeSH
• Middle Aged MeSH
• Humans MeSH
• Prospective Studies MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Arrhythmias, Cardiac * therapy   diagnosis   physiopathology   MeSH
• Heart Rate MeSH
• Treatment Outcome MeSH
• Electric Power Supplies * MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Clinical Trial MeSH
• Multicenter Study MeSH

BACKGROUND: A dual-chamber leadless pacemaker can provide bradycardia therapy to most patients with pacemaker indications without the complications associated with a lead or pulse generator. We sought to confirm whether previously reported 3-month safety and performance outcomes were sustained through 12 months by determining whether 12-month complication-free and performance success rates exceeded their prespecified performance goals. METHODS: Patients were enrolled in the prospective, single-group Aveir DR i2i Study if they had a standard indication for dual-chamber pacing. Enrolled patients were implanted with an Aveir DR dual-chamber leadless pacemaker system, which comprised 2 communicating leadless pacemakers (1 in the right atrium and 1 in the right ventricle). The primary safety outcome evaluated whether freedom from serious device- or procedure-related events through 365 days exceeded the predetermined performance goal of 76.5%. The primary performance outcome determined whether the composite of atrial capture threshold (≤3.0 V at 0.4 ms) and sensing amplitude (P-wave ≥1.0 mV) at the 12-month visit exceeded the predetermined performance goal of 80.0%. RESULTS: Sites attempted implantation in 300 subjects, where 63.3% had sinus-node dysfunction and 33.3% had atrioventricular block as their primary pacing indication. The primary safety end point was achieved, with a Kaplan-Meier 12-month complication-free rate of 88.6% (95% CI, 84.5-91.8; P<0.001). The primary performance end point was achieved in 92.8% of patients (95% CI, 89.7-95.8; P<0.001). CONCLUSIONS: Both primary safety and performance end points were met after 1 year, demonstrating consistency with previously reported 3-month outcomes of a dual-chamber leadless pacemaker. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT05252702.

• MeSH
• Atrioventricular Block * therapy   physiopathology   MeSH
• Bradycardia * therapy   physiopathology   diagnosis   MeSH
• Time Factors MeSH
• Equipment Design MeSH
• Cardiac Pacing, Artificial * adverse effects   methods   MeSH
• Pacemaker, Artificial * MeSH
• Middle Aged MeSH
• Humans MeSH
• Prospective Studies MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Heart Rate * MeSH
• Sick Sinus Syndrome * therapy   physiopathology   diagnosis   MeSH
• Treatment Outcome MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH

BACKGROUND: The growing use of leadless pacemaker (LP) technology requires safe and effective solutions for retrieving and removing these devices over the long term. OBJECTIVES: This study sought to evaluate retrieval and removal of an active helix-fixation LP studied in worldwide regulatory clinical trials. METHODS: Subjects enrolled in the LEADLESS II phase 1 investigational device exemption, LEADLESS Observational, or LEADLESS Japan trials with an attempted LP retrieval at least 6 weeks postimplantation were included. The retrieval success rate was evaluated for all attempted retrievals. Site-reported complications associated with LP retrievals were quantified, with the severity and relationship adjudicated by an independent clinical events committee. RESULTS: There were 1,423 successful LP implants and 234 chronic LP retrieval attempts in 233 subjects. The overall retrieval success rate was 87.6% (205 of 234 attempts). The most common reason for failed retrieval (86.2%, 25 of 29 attempts) was inability to access the LP docking button. The mean time from implantation to attempted retrieval was 3.2 years (range 0.2-9.0 years) and did not significantly influence the retrieval success (P = 0.71). The clinical events committee adjudicated 11 complications in 9 subjects as being retrieval related (3.9%, 9 of 233 subjects). CONCLUSIONS: The safety and efficacy of chronic LP retrieval of an active helix-fixation device was demonstrated in an international clinical trial setting, with implant durations up to 9 years.

• MeSH
• Equipment Design MeSH
• Adult MeSH
• Pacemaker, Artificial * MeSH
• Middle Aged MeSH
• Humans MeSH
• Device Removal * methods   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH

Leadless pacemakers (LPs) are self-contained pacemakers implanted inside the heart, providing a clinical strategy of pacing without pacemaker leads or a subcutaneous pocket. From an experimental therapy first used clinically in 2012, a decade later this technology is an established treatment option. Because of technologic advances and growing evidence, LPs are increasingly being used. Herein, the experience gained from a decade of leadless pacing is reviewed. We cover the safety and efficacy of single-chamber LPs, including comparisons with transvenous pacemakers and various models, and the initial clinical results of the first dual-chamber LP system. Furthermore, evidence and considerations regarding the optimal replacement strategy will be covered. Finally, we discuss future device developments that may broaden indications, such as LPs communicating with subcutaneous implantable cardiac defibrillators and energy-harvesting LPs.

• MeSH
• Equipment Design * MeSH
• Cardiac Pacing, Artificial * methods   trends   MeSH
• Pacemaker, Artificial * trends   MeSH
• Humans MeSH
• Arrhythmias, Cardiac therapy   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

• Publication type
• Case Reports MeSH

AIMS: We report our single-centre experience of mid-term to long-term retrieval and reimplantation of a tine-based leadless pacemaker [Micra transcatheter pacing system (TPS)]. The TPS is a clinically effective alternative to transvenous single-chamber ventricular pacemakers. Whereas it is currently recommended to abandon the TPS at the end of device life, catheter-based retrieval may be favourable in specific scenarios. METHODS AND RESULTS: We report on nine consecutive patients with the implanted TPS who subsequently underwent transcatheter retrieval attempts. The retrieval system consists of the original TPS delivery catheter and an off-the-shelf single-loop 7 mm snare. The procedure was guided by fluoroscopy and intracardiac echocardiography. After an implantation duration of 3.1 ± 2.8 years (range 0.4-9.0), the overall retrieval success rate was 88.9% (8 of 9 patients). The mean procedure time was 89 ± 16 min, and the fluoroscopy time was 18.0 ± 6.6 min. No procedure-related adverse device events occurred. In the one unsuccessful retrieval, intracardiac echocardiography revealed that the TPS was partially embedded in the ventricular tissue surrounding the leadless pacemaker body in the right ventricle. After retrieval, three patients were reimplanted with a new TPS device. All implantations were successful without complications. CONCLUSION: A series of transvenous late retrievals of implanted TPS devices demonstrated safety and feasibility, followed by elective replacement with a new leadless pacing device or conventional transvenous pacing system. This provides a viable end-of-life management alternative to simple abandonment of this leadless pacemaker.

• MeSH
• Time Factors MeSH
• Equipment Design MeSH
• Echocardiography MeSH
• Radiography, Interventional MeSH
• Cardiac Pacing, Artificial methods   MeSH
• Pacemaker, Artificial * MeSH
• Middle Aged MeSH
• Humans MeSH
• Device Removal * methods   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Cardiac Catheterization * methods   instrumentation   MeSH
• Cardiac Catheters MeSH
• Treatment Outcome MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

In a pivotal trial (NCT05252702), the AVEIR DR (Abbott) leadless pacemaker system was found to be safe and effective in delivering DDDR synchronous atrial and ventricular pacing. This dual-chamber system employs 2 leadless pacemakers with implant-to-implant communication. Although implantation of the ventricular device as a single-chamber pacemaker has been well described, there are additional considerations surrounding the dual-chamber implantation procedure. Herein, we review the dual-chamber leadless pacemaker implantation workflow while providing guidance to optimize safe and effective implantation procedures.

• MeSH
• Equipment Design * MeSH
• Prosthesis Implantation methods   instrumentation   MeSH
• Cardiac Pacing, Artificial methods   MeSH
• Pacemaker, Artificial * MeSH
• Humans MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (ICD) is associated with fewer lead-related complications than a transvenous ICD; however, the subcutaneous ICD cannot provide bradycardia and antitachycardia pacing. Whether a modular pacing-defibrillator system comprising a leadless pacemaker in wireless communication with a subcutaneous ICD to provide antitachycardia and bradycardia pacing is safe remains unknown. METHODS: We conducted a multinational, single-group study that enrolled patients at risk for sudden death from ventricular arrhythmias and followed them for 6 months after implantation of a modular pacemaker-defibrillator system. The safety end point was freedom from leadless pacemaker-related major complications, evaluated against a performance goal of 86%. The two primary performance end points were successful communication between the pacemaker and the ICD (performance goal, 88%) and a pacing threshold of up to 2.0 V at a 0.4-msec pulse width (performance goal, 80%). RESULTS: We enrolled 293 patients, 162 of whom were in the 6-month end-point cohort and 151 of whom completed the 6-month follow-up period. The mean age of the patients was 60 years, 16.7% were women, and the mean (±SD) left ventricular ejection fraction was 33.1±12.6%. The percentage of patients who were free from leadless pacemaker-related major complications was 97.5%, which exceeded the prespecified performance goal. Wireless-device communication was successful in 98.8% of communication tests, which exceeded the prespecified goal. Of 151 patients, 147 (97.4%) had pacing thresholds of 2.0 V or less, which exceeded the prespecified goal. The percentage of episodes of arrhythmia that were successfully terminated by antitachycardia pacing was 61.3%, and there were no episodes for which antitachycardia pacing was not delivered owing to communication failure. Of 162 patients, 8 died (4.9%); none of the deaths were deemed to be related to arrhythmias or the implantation procedure. CONCLUSIONS: The leadless pacemaker in wireless communication with a subcutaneous ICD exceeded performance goals for freedom from major complications related to the leadless pacemaker, for communication between the leadless pacemaker and subcutaneous ICD, and for the percentage of patients with a pacing threshold up to 2.0 V at a 0.4-msec pulse width at 6 months. (Funded by Boston Scientific; MODULAR ATP ClinicalTrials.gov NCT04798768.).

• MeSH
• Wireless Technology MeSH
• Bradycardia * therapy   MeSH
• Defibrillators, Implantable * adverse effects   MeSH
• Equipment Design MeSH
• Cardiac Pacing, Artificial adverse effects   methods   MeSH
• Pacemaker, Artificial * adverse effects   MeSH
• Middle Aged MeSH
• Humans MeSH
• Death, Sudden, Cardiac * prevention & control   etiology   MeSH
• Follow-Up Studies MeSH
• Aged MeSH
• Arrhythmias, Cardiac * complications   therapy   MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Clinical Trial MeSH
• Multicenter Study MeSH

BACKGROUND: The first dual-chamber leadless pacemaker (DC-LP) system consists of 2 separate atrial and ventricular devices that communicate to maintain synchronous atrioventricular pacing and sensing. The initial safety and efficacy were previously reported. OBJECTIVE: The purpose of this study was to evaluate the chronic electrical performance of the DC-LP system. METHODS: Patients meeting standard dual-chamber pacing indications were enrolled and implanted with the DC-LP system (Aveir DR, Abbott), including right atrial and ventricular helix-fixation LPs (atrial leadless pacemaker [ALP], ventricular leadless pacemaker [VLP]). Pacing capture threshold, sensed amplitude, and pacing impedance were collected using the device programmer at prespecified timepoints from 0-6 months postimplant. RESULTS: De novo devices were successfully implanted in 381 patients with complete 6-month data (62% male; age 69 ± 14 years; weight 82 ± 20 kg; 65% sinus nodal dysfunction, 30% atrioventricular block). ALPs were implanted predominantly in the right atrial appendage anterior base and VLPs primarily at the mid-to-apical right ventricular septum. From implant to 1 month, pacing capture thresholds (0.4-ms pulse width) improved in both ALPs (2.4 ± 1.5 V to 0.8 ± 0.8 V; P <.001) and VLPs (0.8 ± 0.6 V to 0.6 ± 0.4 V; P <.001). Sensed amplitudes improved in both ALPs (1.8 ± 1.3 mV to 3.4 ± 1.9 mV; P <.001) and VLPs (8.8 ± 4.0 mV to 11.7 ± 4.2 mV; P <.001). Impedances were stable in ALPs (334 ± 68 Ω to 329 ± 52 Ω; P = .17) and reduced in VLPs (789 ± 351 Ω to 646 ± 190 Ω; P <.001). Electrical measurements remained relatively stable from 1-6 months postimplant. No differences in electrical metrics were observed among ALP or VLP implant locations. CONCLUSION: This first in-human evaluation of the new dual-chamber leadless pacemaker system demonstrated reliable electrical performance throughout the initial 6-month evaluation period.

• MeSH
• Atrioventricular Block therapy   physiopathology   MeSH
• Time Factors MeSH
• Equipment Design * MeSH
• Cardiac Pacing, Artificial * methods   MeSH
• Pacemaker, Artificial * MeSH
• Humans MeSH
• Follow-Up Studies MeSH
• Aged MeSH
• Heart Ventricles physiopathology   MeSH
• Sick Sinus Syndrome therapy   physiopathology   MeSH
• Treatment Outcome MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH