First-in-man report of transsubclavian venous implantation of the Aveir leadless cardiac pacing system

INTRODUCTION

Transsubclavian venous implantation of the Aveir leadless cardiac pacemaker (LCP) has not been previously reported.

METHODS AND RESULTS

Three cases of transsubclavian implantation of the Aveir LCP are reported. Two cases were postbilateral orthotopic lung transplant, without appropriate femoral or jugular access due to recent ECMO cannulation and jugular central venous catheters. In one case, there was strong patient preference for same-day discharge. Stability testing confirmed adequate fixation and electrical testing confirmed stable parameters in all cases. All patients tolerated the procedure well without significant immediate complications.

CONCLUSIONS

We demonstrate the feasibility of transsubclavian implantation of the Aveir LCP.

Leadless pacemakers: Where are we?

Pacemakers have been the cornerstone of brady-arrhythmia management since the mid-20th century. Despite the widespread use and success of traditional transvenous pacemakers, they are associated with an estimated 15 % complication rate at three years. Driven by the advantages over traditional transvenous pacemakers including a lack of transvenous leads, resistance to infection, and ease of implantation, the number of leadless pacemakers placed annually in the United States has dramatically increased since their initial approval. While current iterations of leadless pacemakers lack the versatility offered by transvenous devices, recent advances in leadless pacing offer an increasingly diverse range of therapeutic options. This review will discuss the past, present, and future emerging technologies, and strategies in leadless pacing.

Early real-world implant experience with a helix-fixation ventricular leadless pacemaker

BACKGROUND

Roughly one in six patients receiving conventional transvenous pacemaker systems experience significant complications within 1 year of implant, mainly due to the transvenous lead and subcutaneous pocket. A new helix-fixation single-chamber ventricular leadless pacemaker (LP) system capable of pre-deployment exploratory electrical mapping is commercially available. Such an LP may mitigate complications while streamlining the implantation. In this study, the initial real-world implant experience of the helix-fixation LP was evaluated following its commercial release.

METHODS

In patients indicated for single-chamber right ventricular pacing, helix-fixation Aveir VR LPs (Abbott, Abbott Park, IL) were implanted using the dedicated loading tool, introducer, and delivery catheter. Implant procedural characteristics, electrical parameters, and any 30-day procedure-related adverse events of consecutive implant attempts were retrospectively evaluated.

RESULTS

A total of 167 patients with Class I indication for permanent pacing received implants in four North American centers (57% male, 70 years old). Pre-fixation electrical mapping of potential sites allowed repositioning to be avoided in 95.7% of patients. Median [interquartile range] LP procedure and fluoroscopy durations were 25.5 min [20.0, 35.0] and 5.7 min [4.0, 9.2], respectively. Pacing capture threshold, sensed R-wave amplitude, and impedance were 0.8 V [0.5, 1.3], 9.0 mV [6.0, 12.0], and 705 Ω [550, 910], respectively. Implantation was successful in 98.8% of patients, with 98.2% free from acute adverse events.

CONCLUSIONS

The initial, real-world experience of the helix-fixation ventricular leadless pacemaker demonstrated safe and efficient implantation with minimal repositioning, viable electrical metrics, and limited acute complications.

Different leadless pacemakers working in harmony (Aveir in the atrium/Micra AV2 in the ventricle) in a patient with dextrocardia and double outlet right ventricle after high-risk infected device extraction

INTRODUCTION

Patients with congenital heart disease are at increased risk for requiring cardiac pacing during their lifetime.

METHODS

We present the first described case of using two leadless pacing systems manufactured by separate companies implanted within the same patient to provide atrial and ventricular pacing due to complex congenital anatomy.

RESULTS

A 27-year-old male with dextrocardia with double outlet right ventricle, subaortic ventricular septal defect, and pulmonary stenosis status-post pulmonary valve replacement complicated by ventricular pacing dependence and subsequent atrial pacing dependence after atriotomy-based atypical flutter ablation developed recurrent mediastinitis and pocket infection with erosion despite prolonged antibiotic treatment. Due to atrial and ventricular pacing dependence, a comprehensive congenital care team concluded the need for lead extraction and replacement of pacemaker via leadless peacemaking device. Laser-lead extraction and temporary atrial pacemaker placement was performed. Afterward, a transesophageal echocardiogram guided implantation of both a Micra AV 2 (Medtronic) leadless pacemaker in the interventricular septum within the right ventricle and an Aveir (Abbott) leadless pacemaker in the superior base of the right atrial appendage was performed with successful pacing. Although there is no communication between these devices, atrial-mechanical ventricular pacing was reliable with good implant thresholds, impedances and sensing from both devices.

CONCLUSION

Our case demonstrates the feasibility of using dual leadless pacing modalities to simultaneously pace someone at complex, prohibitive risk for temporary permanent or permanent pacemaker devices.

Aveir VR real-world performance and chronic pacing threshold prediction using mapping and fixation electrical data

AIMS

Aveir VR performance and predictors for its pacing threshold (PCT) in a real-world cohort were investigated.

METHODS

Electrical measurements at various stages of an Aveir VR implant were prospectively collected. Predictors for 3-month PCT were studied. A retrospective cohort of consecutive 139 Micra implants was used to compare the PCT evolution. High PCT was defined as ≥1.5 V, using a pulse width of 0.4 ms for Aveir and 0.24 ms for Micra. Excellent PCT was defined as ≤0.5 V at the respective pulse width.

RESULTS

Among the 123 consecutive Aveir VR implant attempts, 122 (99.2%) were successful. The majority were of advanced age (mean 79.7) and small body size (mean BSA 1.60). Two patients (1.6%) experienced complications, including one pericardial effusion after device reposition and one intraoperative device dislodgement. Eighty-eight patients reached a 3-month follow-up. Aveir 3-month PCT was correlated with impedance at mapping (P = 0.015), tether mode (P < 0.001), end-of-procedure (P < 0.001), and mapping PCT (P = 0.035), but not with PCTs after fixation (P > 0.05). Tether mode impedance >470 ohms had 88% sensitivity and 71% specificity in predicting excellent 3-month PCT. Although it is more common for Aveir to have high PCT at end of procedure (11.5% for Aveir and 2.2% for Micra, P = 0.004), the rate at 3 months was similar (2.3% for Aveir and 3.1% for Micra, P = 1.000).

CONCLUSION

Aveir VR demonstrated satisfactory performance in this high-risk cohort. Pacing thresholds tend to improve to a greater extent than Micra after implantation. The PCT after fixation, even after a waiting period, has limited predictive value for the chronic threshold. Low-mapping PCT and high intraoperative impedance predict chronic low PCT.

First report of an Aveir retrievable leadless pacemaker in a pediatric patient, via internal jugular vein access

BACKGROUND

The Aveir device allows retrievability and mapping prior to fixation over alternative leadless pacemakers.

CASE SUMMARY

We describe the first case of Aveir leadless pacemaker implantation into a 44.5 kg, pediatric patient with symptomatic sinus dysfunction. Access by the right internal jugular vein (RIJ) with 1st attempt implantation into the septal location.

DISCUSSION

Placement of the Aveir leadless pacemaker is feasible in a 44.5 kg pediatric patient via a RIJ approach.

Adverse events associated with AveirTM VR leadless pacemaker: A Food and Drug Administration MAUDE database study

BACKGROUND

Leadless pacemaker (LP) offers an innovative approach for treating bradyarrhythmia, thus avoiding pacemaker pocket and lead-related complications. The Food and Drug Administration (FDA) has recently approved the Aveir™ leadless pacing system (screw-in type LP).

METHODS

We queried the FDA MAUDE database to study the safety profile and assess the types of complications with this relatively novel device technology. A MAUDE database search was conducted on January 20, 2023, for reports received post-FDA approval to capture all adverse events.

RESULTS

A total of 98 medical device report were reported for Aveir™ LP. After excluding duplicate, programmer-related, or introducer-sheath-related entries (n = 34), 64 entries were included. The most commonly encountered problem was high threshold/noncapture (28.1%, 18 events), followed by stretched helix (17.2%, 11 events) and device dislodgement (15.6%, ten events-5 intraprocedural, while 5 in the postoperative Day 1). Other reported events included high impedance (14.1%, nine events), sensing issues (12.5%, eight events), bent/broken helix (7.8%, five events), premature separation (4.7%, three events), interrogation problem (3.1%, two events), low impedance (3.1%, two events), premature battery depletion (1.6%, one event) and inadvertent MRI mode switch (1.6%, one event) and miscellaneous (15.6%, n = 10). There were eight serious patient injury events-pericardial effusion requiring pericardiocentesis (7.8%, five events) due to cardiac perforation that resulted in two deaths (3.1%) followed by sustained ventricular arrhythmias (4.6%, n = 3).

CONCLUSION

In our study assessing the real-world safety profile of the Aveir™ LP, serious adverse events have been reported-life-threatening ventricular arrhythmias, pericardial effusion, device explantation/reimplantation, and death.

Advanced helix-fixation leadless cardiac pacemaker implantation techniques to improve success and reduce complications

INTRODUCTION

Leadless cardiac pacemakers (LCPs) are becoming more commonly utilized because of their potential advantages (i.e., reduced short and long-term complications, improved patient comfort) and may be the preferred option for patients with venous access problems, high-risk for infection, previous lead fractures, or skin erosion. There are currently two types of LCP fixation mechanisms that have been FDA approved-Medtronic's Micra system has a tine-based fixation and Abbott's Aveir system has a helix-fixation design. This article highlights important tips and tricks for a successful implant of a helix-fixation LCP, particularly when difficulties are encountered, and provides precautions to avoid potential complications.

METHODS

Cases of single chamber Aveir LCP implantation were reviewed to highlight examples of procedural pitfalls and suggested methods to circumnavigate them.

RESULTS

There are unique procedural considerations regarding the Aveir LCP implant as well as challenges that that may be occasionally encountered. Techniques to address these-such as avoiding air embolism, maneuvering difficult entry into the right ventricle, handling complicated positioning/repositioning, evaluating proper fixation, and releasing difficult tethers-are illustrated in detail. Advice to reduce risks of perforation and to position optimally for potential retrieval and communication for dual chamber pacing are also described.

CONCLUSIONS

The advanced teaching concepts described and emphasized in this article may help improve success and prevent procedural complications, especially when physicians are learning how implant these novel helix-fixation LCPs.

Dual-Chamber Leadless Pacing: Atrioventricular Synchrony in Preclinical Models of Normal or Blocked Atrioventricular Conduction

BACKGROUND

Dual-chamber leadless pacemakers (LP) require robust communication between distinct right atrial (RA) and right ventricular (RV) LPs to achieve atrioventricular (AV) synchrony.

OBJECTIVE

This preclinical study evaluated a novel, continuous implant-to-implant (i2i™) communication methodology for maintaining AV-synchronous, dual-chamber DDD(R) pacing by the 2 LPs.

METHODS

RA and RV LPs were implanted and paired in 7 ovine subjects, 4 of 7 with induced complete heart block. AV synchrony (% AV intervals <300 ms) and i2i communication success (% successful i2i transmissions between LPs) were evaluated acutely and chronically. During acute testing, 12-lead ECG and LP diagnostic data were collected from 5-minute recordings, in 4 postures and 2 rhythms (AP-VP and AS-VP or AP-VS and AS-VS) per subject. Chronic i2i performance was evaluated through 23 weeks post-implant (final i2i evaluation period: week 16-23).

RESULTS

Acute AV synchrony and i2i communication success across multiple postures and rhythms were 100.0% [100.0-100.0] (median [interquartile range]) and 99.9% [99.9-99.9], respectively. AV synchrony and i2i success rates did not differ across postures (P=0.59, P=0.11) or rhythms (P=1.00, P=0.82). During the final i2i evaluation period, the overall i2i success was 98.9% [98.1-99.0].

CONCLUSION

Successful AV-synchronous, dual-chamber DDD(R) leadless pacing using a novel, continuous, wireless communication modality was demonstrated across variations in posture and rhythm in a preclinical model.