Retrieval and Replacement of a Helix-Fixation Leadless Pacemaker at 9 Years Post-implant

Case report demonstrating novel approaches for leadless pacemaker implantation in the single ventricle heart

Background

The congenital heart disease population can provide a unique set of challenges during pacemaker implant, including the necessity of transvenous leads in a young group of patients. In this case report we demonstrate how leadless pacemakers may be used as an option in patients with Fontan circulation.

Case Summary

We present two cases of novel use of the Abbott AVEIR™ leadless pacemaker, including the first reported in person trans-baffle delivery of this device and implantation into a single ventricle heart. Our cases are a 30-year-old male with single ventricle physiology and Fontan circulation, found incidentally to have complete heart block (CHB) and a 48-year-old female with a Fontan circulation who had CHB and a history of syncope. These cases demonstrate a variety of venous access routes and add to the existing data of leadless pacemaker implantation in single ventricle physiology. The very long battery life of these devices make them ideal for patients with difficult venous access with bradycardia pacing requirement with low pacing burden.

Discussion

Leadless pacemakers offer a valuable alternative to transvenous pacing leads for providing bradycardia pacing support in this patient population.

Worldwide Chronic Retrieval Experience of Helix-Fixation Leadless Cardiac Pacemakers

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.

Long-term management of leadless pacemakers

Leadless pacemakers (LPs) are increasingly being used to treat bradyarrhythmias, and end of service (EOS) management decisions are becoming increasingly important given finite battery lifespans. Two strategies have been adopted for device EOS: LP abandonment and LP removal. Certain scenarios including high degree of LP encapsulation and 'last expected' pacing devices favour LP abandonment, while other LP complications may necessitate device removal. When abandoning LP, clinicians must understand design, performance, and safety considerations for devices left in place. When removing LP, specialized tools and techniques have been developed, each varying by device manufacturer and model. Case reports and series on LP removal have elucidated how to overcome challenges that may arise during removal. Despite best practice techniques, complications can arise before and after removal. Current studies on LP EOS management are limited, and further studies are needed to help understand predictors of successful device removal and long-term sequelae of both strategies. The aim of this state-of-the-art review is to help clinicians understand current strategies and considerations for both LP abandonment and removal.

Applications of leadless pacing

Leadless pacemakers are being used with increased frequency due to improvements in the technologies, and the recognition of the substantial benefits over traditional transvenous devices. Current information shows a substantial reduction in morbidity with leadless devices which has resulted in a significant expansion in the indication for these devices. Patient selection now includes a younger population as well as those commonly excluded from consideration. Understanding these new applications will allow a larger group of patients to benefit from the significant advantages of leadless devices while not compromising quality and effective pacing. Further improvements in this technology will result in even more availability of these transformative devices.

Implantation techniques for a helix-fixation dual-chamber leadless pacemaker

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.

Patient Preferences for Features Associated With Leadless Versus Conventional Transvenous Cardiac Pacemakers

BACKGROUND

Regulatory approval of the first dual-chamber leadless pacemaker system provides patients an alternative to conventional transvenous pacemakers. The study objective was to quantify the preferences of patients for pacemaker features.

METHODS

Patients with a de novo (ie, initial) pacemaker indication were recruited from 7 US sites to complete a Web-based discrete-choice experiment survey between May 11, 2022, and May 24, 2023. Patients chose between pairs of experimentally designed, hypothetical pacemakers that varied according to type (removable leadless, nonremovable leadless, or conventional transvenous); battery life (5, 8, 12, or 15 years); time since regulatory approval (2 or 10 years); discomfort for 6 months (none or discomfort); and complication risk and infection risk (1%, 5%, or 10%/20% for each). Patients' choice data were analyzed using random-parameter logit models and latent-class analysis.

RESULTS

Among 117 participants, the mean (SD) age was 67.3 (14.6) years, 94% were white, and 42% were female. On average, patients' survey responses revealed a preference for removable leadless pacemakers (β, 0.340; SE, 0.096) over both nonremovable leadless pacemakers (β, -0.310; SE, 0.131; P=0.001) and conventional transvenous pacemakers (β, -0.030; SE, 0.119; P=0.031). However, latent-class analysis revealed 2 distinct preference classes. One class preferred leadless pacemakers (50.5%), and the other class preferred conventional transvenous pacemakers (49.5%). The conventional pacemaker class prioritized pacemakers with 10 rather than 2 years since regulatory approval (P<0.001), whereas the leadless pacemaker class was insensitive to years since regulatory approval (P=0.83). Complication risks and infection risks were found to be the most influential. All else equal, patients would accept maximum risks of complications or infections ranging about 5% to 18% to receive their preferred pacemaker type.

CONCLUSIONS

Latent-class analysis revealed strong patient preferences for the type of pacemaker, with a nearly equal split between recent leadless pacemaker technology and conventional transvenous pacemakers. These findings can inform shared decision-making between health care providers and patients.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT05327101.

Traditional and Non-traditional Lead Extraction Techniques

With increasing volume of cardiac implantable electronic devices in the last decade, the indications for device extraction have increased. Multidisciplinary collaboration between cardiothoracic surgeons, cardiac anesthesiologists, and cardiac electrophysiologists has been recognized as an essential pre-requisite in pre-procedural planning to limit complications from this inherently risky procedure. Fortunately, the tools and techniques have continued to evolve to make extraction safer and more effective. This article discusses traditional and non-traditional techniques for transvenous lead extraction in addition to retrieval of leadless pacemakers.

Challenging Extraction and Replacement of an Eight-year-old Nanostim Leadless Pacemaker and AVEIR Implant

Leadless pacemakers (LPs) are emerging options for bradyarrhythmias. However, extraction can be risky if the device is in an unfavorable position. We present a challenging case of a Nanostim LP (NLP) (Abbott Medical Inc., Abbott Park, IL, USA) placed 8 years prior to removal and subsequent replacement with an AVEIR LP (ALP) (Abbott). A 72-year-old man received an NLP in 2015 for persistent atrial fibrillation with bradycardia. The NLP could not be interrogated in our office. An external event monitor demonstrated persistent atrial fibrillation with bradycardia and pauses. A premature battery depletion of the NLP was suspected. An ALP was chosen for replacement. On a computed tomography scan of the chest, the NLP was seen in the mid-free wall of the right ventricle, and its proximal portion abutted the tricuspid annulus. The AVEIR retrieval catheter (ARC) was used for retrieval. Multiple attempts were made to snare the device, yet it proved difficult due to poor placement and button tissue formation. The snare became damaged, and a second ARC was needed. On the successful attempt, the NLP was snared proximally and permitted docking. We advanced the protective sleeve over the NLP body, but resistance was observed due to tissue growth. Counterclockwise torsion was applied, and the device disconnected. Once the NLP was in linear orientation, the protective sleeve was eventually positioned over its body, allowing removal. The ALP was then installed without difficulty or structural complications. This report shows the importance of proper LP placement in the right ventricular septal wall. LP removal can be performed safely, yet complications can arise based on the age and location of the LP. The ARC can be successfully used to extract non-AVEIR LPs with evidence of docking button tissue growth. Similar interventions should exercise caution when attempting extraction and subsequent implantation.

Transcatheter non-acute retrieval of the tine-based leadless ventricular pacemaker

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.

Atrial placement of Aveir-VR leadless pacemaker in a patient with complex cardiac anatomy

Leadless pacemakers have provided new treatment modalities that can be especially useful in patients with complex cardiac anatomy and contraindications toward other pacemaker approaches. The Aveir™ single-chamber (VR) leadless pacemaker (LP) (Abbott Laboratories, Chicago, IL) is a recently approved device that can be placed in the right ventricle for patients with bradycardia. In this case, we present a novel use for the device through placement in the atrium to control atrial flutter in a patient with a hypoplastic right ventricle.

Retrievable leadless pacemakers (Aveir VR) may be beneficial in adult patients with congenital heart disease

INTRODUCTION

Congenital heart disease may present in up to 1.6 % of newborns. Given high burden of pacing need in adult patients with repaired congenital heart disease and availability of different pacing options, more information on outcomes of newer pacemaker types are needed. Retrievable leadless pacemaker implants in adult congenital patients have not been described.

METHODS

Retrospective review of three Aveir (Abbott) retrievable leadless pacemaker implants were reviewed at the UC Davis Medical Center. All patients underwent implant via femoral access.

RESULTS

All patients had one deployment only, after mapping prior. No complications occurred. Implant thresholds were 0.5 V (V) @0.2msilliseconds (ms) for patients 1 and 2 and 1 V @0.4 ms for patient 3. With impedances between 500 and 1290 Ω. Sensing was 5.5-8 mV (mV). Follow-up occurred up to one year (for two patients) with similar values overall. The predicted longevities of each device were between 22.6 and >25 years.

CONCLUSION

Safety and short-mid-term parameters of retrievable leadless pacemaker implantation is reported in three patients with adult congenital heart disease.