The learning curve associated with the implantation of the Nanostim leadless pacemaker

Comparison of Safety of Leadless Pacemakers and Transvenous Pacemakers: A Meta-Analysis

Pacemakers have been accessible for six decades, and clearly defined criteria for pacemaker implantation have been established. Within the contemporary clinical practice, two dependable pacing platforms exist leadless pacemakers and transvenous pacemakers. The aim of this meta-analysis is to compare the safety of leadless pacemakers to transvenous pacemakers. This meta-analysis adhered to the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 framework. A comprehensive and systematic search was conducted across various databases including Scopus, Cochrane Library, and EMBASE, spanning from inception to August 15, 2023. The primary outcomes assessed in this meta-analysis were total complications, all-cause mortality, and device-related complications. Furthermore, secondary outcomes evaluated encompassed the need for reintervention, occurrences of pneumothorax, pericardial effusion, endocarditis, hemothorax, and hematoma. Total 17 studies were included in this meta-analysis. The findings of this study showed that patients with leadless pacemakers had a lower risk of total complications, device-related complications, pneumothorax, and endocarditis. The risk of reintervention was significantly lower in the leadless pacemaker group. However, compared to a transvenous pacemaker, the risk of pericardial effusion was significantly higher in the leadless pacemaker group. It is important to acknowledge the limitations arising from the lack of extensive long-term follow-up data for leadless pacemakers. As technology evolves, continued research will be essential in uncovering the full spectrum of prolonged complications associated with these devices.

Leadless Pacemaker Perforations: Clinical Consequences and Related Device and User Problems

Background

Cardiac perforation during leadless pacemaker implantation is more likely to require intervention than perforation by a transvenous lead. This study reports the consequences of Micra pacemaker perforations and related device and operator use problems based on information the manufacturer has submitted to the Food and Drug Administration (FDA).

Methods

FDA's Manufacturer and User Facility Device Experience (MAUDE) database was searched for Micra perforations. Data extracted included deaths, major adverse clinical events (MACEs), and device and/or operator use problems.

Results

Between 2016 and July 2021, 563 perforations were reported within 30 days of implant and resulted in 150 deaths (27%), 499 cardiac tamponades (89%), 64 pericardial effusions (11%), and 146 patients (26%) required emergency surgery. Half of perforations were associated with 139 (25%) device problems, 78 (14%) operator use problems, and 62 (11%) combined device and operator use problems. Inadequate electrical measurements or difficult positioning were the most frequent device problems (n = 129); non‐septal implants and perforation of other structures were the most frequent operator use problems (n = 69); a combined operator use and device problem resulted in 62 delivery system perforations. No device or operator use problem was identified for 282 perforations (50%), but they were associated with 78 deaths, 245 tamponades, and 57 emergency surgeries.

Conclusion

The Micra perforations reported in MAUDE are often associated with death and major complications requiring emergency intervention. Device and use problems account for at least half of perforations. Studies are needed to identify who is at risk for a perforation and how MACE can be avoided or mitigated.

Leadless pacemakers: A review of current data and future directions

Leadless pacemakers (LPs) have revolutionized the field of pacing by miniaturizing pacemakers and rendering them completelty intracardiac, hence reducing complications related to pacemaker pockets and transvenous leads. However, first generation LPs appear to be associated with a higher rate of myocardial perforation as compared to transvenous pacemakers (TV-PPM). Currently, LPs are predominantly designed to pace the right ventricle with no LPs that provide atrial or biventricular pacing. In this article, we review the available data on LPs while advocating for the need for a randomized controlled trial comparing LPs to TV-PPMs. In addition, we review the future directions of leadless devices.

Leadless pacemaker implantation quality: importance of the operator's experience

AIMS

Leadless cardiac pacemaker (PM) implantation differs from conventional PM implantation. While the procedure has been considered safe, recent real-world data raised concerns about the learning curve of new operators and their implantation quality. The goal of this study was to investigate the influence of the first operator's experience on leadless PM implantation quality and procedural efficiency.

METHODS AND RESULTS

We performed a bicentric analysis of all Micra TPS™ implantations in two large tertiary referral hospitals. We assessed both leadless PM implantation quality based on the absence of complications (requiring intervention or prolonged hospitalization), good electrical performance (pacing threshold ≤ 1.5 V/0.24 ms, R-wave amplitude > 5 mV), and acceptable fluoroscopy duration (<10 min) as well as procedural efficiency in relation to the operator's experience. Univariate and multivariate logistic regression analyses were performed to identify predictors for implantation quality and procedural efficiency. Leadless PM implantation was successful in 106/111 cases (95.5%). Three patients (2.7%) experienced acute complications (one cardiac tamponade, one femoral bleeding, one posture-related PM exit block). Multivariate analysis showed that implantation quality of more experienced first operators was higher [odds ratio 1.09 (95% confidence interval 1.00-1.19), P = 0.05]. Procedural efficiency increased with operator experience as evidenced by an inverse correlation of procedure time, time to the first deployment, fluoroscopy time, and the number of procedures performed (all P < 0.05).

CONCLUSION

The operator's learning curve is a critical factor for leadless PM implantation quality and procedural efficiency.

A Meta-analysis of Major Complications between Traditional Pacemakers and Leadless Pacemakers

Objectives: We aim to compare the major complications between leadless pacemakers and traditional pacemakers.Background: Leadless pacemakers, which are increasingly used in clinical practice, have several advantages compared with traditional pacemakers in avoiding pocket- and lead-related complications. However, the clinical effect of leadless pacemakers remains controversial.Methods: PubMed, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), the CNKI database, and the Wanfang database were searched from July 2013 to December 2019. Studies comparing leadless pacemakers and traditional pacemakers were included. The primary end point was major complications. The secondary end points were cardiac perforation/pericardial effusion, device revision or extraction, loss of device function, and death.Results: Six studies fulfilled the inclusion criteria. Only four of the six studies reported data on major complications. Leadless pacemakers were associated with a lower incidence of major complications (risk ratio 0.33, 95% confidence interval 0.25‐0.44, P<0.00001, I2=49%). We extracted data on cardiac perforation/pericardial effusion, device revision or extraction, loss of device function, and death from six studies. Our meta-analysis showed that leadless pacemakers have a higher risk of cardiac perforation or pericardial effusion (risk ratio 4.28, 95% confidence interval 1.66‐11.08, P=0.003, I2=0%). No statistically significant differences were found for mortality, device revision or extraction, and loss of device function.Conclusion: Compared with traditional pacemakers, leadless pacemakers have a significantly decreased risk of major complications, but have a higher risk of cardiac perforation or pericardial effusion.

Single-chamber leadless pacemaker for atrial synchronous or ventricular pacing

Leadless pacing is a major breakthrough in the management of bradyarrhythmia. Results of initial clinical trials that have demonstrated a significant reduction in acute and long-term pacing-related complications have been confirmed by real-world experience in a broader spectrum of patients. Nonetheless current use of a leadless pacemaker is hampered by its limited atrial sensing and pacing capability, as well as battery life-span and retrievability. We review the current clinical outcome data, indications and contraindications, implantation and retrieval techniques, synchronous ventricular pacing, and other clinical considerations. We also provide an overview of the latest advancements in leadless pacing technology including device-to-device communication and energy harvesting technology.

Clinical outcomes of leadless pacemaker: a systematic review

INTRODUCTION

Transvenous pacemakers are associated with a significant amount of complications. Leadless pacemakers (LP) are emerging as an alternative to conventional devices. This article provides a systematic review of patient eligibility, safety and clinical outcomes of the LP devices.

EVIDENCE ACQUISITION

A systematic search for articles describing the use of LP was conducted. Out of two databases, 24 articles were included in the qualitative analysis. These articles comprised a total of 4739 patients, with follow-up times of 1-38 months. Further information was obtained from 10 more studies.

EVIDENCE SYNTHESIS

From a population of 4739 patients included in the qualitative analysis, 4670 LP were implanted with success (98.5%). A total of 248 complications were described (5.23%) during the follow-up. The most common were pacing issues such as elevated thresholds, dislodgements or battery failure (68 patients), events at the femoral access site such as hemorrhage, hematoma or pseudoaneurysms (64 patients) and procedure related cardiac injuries such as cardiac perforation, tamponade or pericardial effusion (47 patients). There were 360 deaths during the follow-up and 11 were described as procedure or device related. Four studies presented the strategy of using a combined approach of atrioventricular node ablation (AVNA) and LP implantation.

CONCLUSIONS

Leadless pacemakers seem to have a relatively low complication rate. These devices may be a good option in patients with an indication for single-chamber pacing, in patients with conditions precluding conventional transvenous pacemaker implantations. Studies directly comparing LP and transvenous pacemakers and data on longer follow-up periods are needed.