epocrates

FDA approves world’s first dual-chamber leadless pacing system

July 13, 2023

What’s new in leadless pacemakers?

On July 5th the FDA approved the first dual-chamber leadless pacemaker system developed by Abbott. The Aveir dual-chamber (DR)™ leadless pacemaker system combines Abbott's previously approved 2022 Aveir VR device, its single-chamber leadless pacemaker system for the right ventricle, with the newly authorized smaller Aveir AR device designed to pace the right atrium.

Historically, leadless or wireless pacing options have been limited to single-chamber devices that only pace the ventricle because synchronization of two leadless pacemakers had been difficult to achieve (Abbott, 2023).

How does it work?

Abbott's Aveir DR system consists of two leadless pacemakers, one implanted in the right ventricle and one in the right atrium. Once both pacemakers are in place, Abbott's i2i technology uses high-frequency pulses to send beat-to-beat messages through the blood between the devices, allowing for synchronized or coordinated cardiac pacing.

The wireless pacemaker is about 90% smaller than the average pacemaker—resembles a small metal cylinder, and is roughly the size of a AAA battery.

Unlike traditional pacemakers, leadless pacemakers are placed directly into the lower right ventricle via the femoral vein. The Aveir DR device attaches to the myocardium with a screw-in mechanism—known as a helix—that allows for future retrieval of the device should therapy needs evolve, or the device needs to be replaced (Abbott, 2023). 

What’s the potential patient impact?

The recently approved dual-chamber technology is expected to enable more U.S. patients to have a leadless pacemaker since more than 80% of people who need a pacemaker require pacing in both the right atrium and right ventricle.

This is the first leadless pacemaker on the market that can be retrieved or taken out after a number of years, providing a minimally invasive option for people who need pacing to treat a variety of slow or abnormal heart rhythms (Abbott, 2023).

The leadless aspect also limits complications associated with transvenous pacemakers including pocket infections, hematoma, lead dislodgment, and lead fracture (Webb, 2019).

What’s the evidence?

The FDA approved this system based on results of the Aveir DR i2i study, published recently in the New England Journal of Medicine. Among the 300 patients enrolled, 190 (63.3%) had sinus-node dysfunction and 100 (33.3%) had AV block as the primary pacing indication. The procedural success rate was 98.3%. The dual-chamber leadless pacemaker system met the primary safety end point and provided atrial pacing and reliable atrioventricular synchrony for three months after implantation, with 97.3% of patients achieving at least 70% atrioventricular synchrony, which exceeded the performance goal of 83%. 

In this study, no procedure or device-related deaths occurred. A total of 35 device- or procedure-related serious adverse events occurred in 29 patients. The incidence of acute complications was similar to that observed in studies of transvenous dual-chamber pacemakers. Serious cardiac injury (pericardial effusion) occurred in 0.7% of the patients, which compares favorably to both the 0.8% incidence of perforation in a recent meta-analysis of transvenous pacemaker studies and the 1.5% incidence of perforation in the initial single-chamber leadless pacemaker trials.

Study authors did observe a "higher-than-expected" incidence of dislodgement during and after the implantation procedure: 1.7% for each, as compared with the 1.1% in the initial trial of the ventricular leadless pacemaker (Knops, 2023).

What are the benefits of dual-chamber leadless pacemakers?

• Chronic retrievability - This is the first leadless pacemaker on the market that can be removed after a number of years and upgraded as needed. For most other types of pacemakers, the original device needs to remain in the body along with the replacement device, which can be especially concerning for younger patients who may require several replacements over a lifetime.
• Mapping prior to fixation - The Aveir DR system is designed to provide real-time pacing analysis, so physicians can assess proper placement of the device during the implantation procedure, thus limiting potential complications from needing to reposition the device.
• Battery life - The battery life of leadless pacemakers are comparable to traditional transvenous pacemakers. Longer time intervals between interventions result in fewer procedures over a patient's lifetime and a reduced likelihood of complications. Abbott says its Aveir DR system uses less battery current than inductive, radio frequency or Bluetooth® communication—the other modalities used in implantable medical devices or traditional pacemakers (Abbott, 2023).
• Cosmetic advantage - Patients won't have an incision scar on the chest or a skin protrusion as they would with traditional pacemakers.
• Shorter recovery - The implantation procedure generally takes 30 minutes to complete, with a shorter recovery period during which patients don't need to restrict upper-body movements as much as they would with traditional pacemakers (Derrick, 2022).

Other advantages of leadless pacemakers include decreased infection risk, overcoming limited vascular access, and avoidance of interaction with the tricuspid valve apparatus (Blank, 2023).

Researchers estimate that eliminating transvenous leads and the generator pocket reduces the long-term risk of infection and lead malfunction that may affect one in six patients during three years of follow-up (Knops, 2023).

What are the risks and disadvantages?

Potential complications associated with the use of the Aveir DR system are the same as with the use of single- or dual-chamber pacemakers with active fixation pacing leads including, but not limited to: cardiac perforation, cardiac tamponade, pericardial effusion, pericarditis, valve damage and/or regurgitation, heart failure, pneumothorax/hemothorax, cardiac arrhythmias, diaphragmatic/phrenic nerve stimulation/ extra-cardiac stimulation, palpitations, hypotension, syncope, cerebrovascular accident, infection, hypersensitivity reaction to device materials, contrast media, medications, or direct toxic effect of contrast media on kidney function (Abbott, 2023).

Disadvantages of leadless pacemakers include unclear lifecycle management, cost, and lack of integration with defibrillator systems (Blank, 2023). 

References

Knops RE, et al. (2023, June 22). A Dual-Chamber Leadless Pacemaker. New Engl J Med. June 22;388(25):2360-2370. https://pubmed.ncbi.nlm.nih.gov/37212442/

(2023, July 5). Abbott receives FDA approval for world’s first dual chamber leadless pacemaker. Abbott Newsroom. https://abbott.mediaroom.com/2023-07-05-Abbott-Receives-FDA-Approval-for-Worlds-First-Dual-Chamber-Leadless-Pacemaker

Derrick L. (2022, October 4). Local doctor implants one of the first wireless, dual chamber pacemakers. UGA Today. University of Georgia. https://news.uga.edu/doctor-implants-wireless-dual-chamber-pacemakers/

Webb S. (2019, June 10). The Leadless Pacemaker. American College of Cardiology. https://www.acc.org/Latest-in-Cardiology/ten-points-to-remember/2019/06/10/13/49/The-Leadless-Pacemaker

Blank E.A., et al. (2023, March 31). Leadless Pacemakers: State of the Art and Selection of the Ideal Candidate. Curr Cardiol Rev. https://pubmed.ncbi.nlm.nih.gov/36999695/

Knops Re, et al. (2023, May 22). A Dual-Chamber Leadless Pacemaker Study. American College of Cardiology. https://www.acc.org/Latest-in-Cardiology/Journal-Scans/2023/05/22/15/36/a-dual-chamber-leadless