Dual-chamber leadless pacemaker shown to be safe and effective in Aveir DR i2i Study

The study revealed that the implantation procedure comprising two functioning leadless pacemakers that established implant-to-implant communication met the primary safety endpoint and provided atrial pacing and reliable atrioventricular synchrony for three months. The procedure was successful in 98.3% (n=295 of 300) of trial patients, researchers reported at the Heart Rhythm Society (HRS) meeting.

Previous studies have shown that single-chamber ventricular leadless pacemakers are not favourable for atrial pacing or consistent atrioventricular synchrony. A dual-chamber leadless pacemaker system comprising percutaneous implantation of two devices, one in the right atrium and one in the right ventricle, would make leadless pacemaker therapy a treatment option for many indications.

Daniel Cantillon, MD, of Masimo in Irvine, California, and colleagues conducted a multicenter, prospective, ingle-group study to assess the performance and safety of a dual-chamber leadless pacemaker system. Patients with a conventional indication for dual-chamber pacing were included. Freedom from complications (procedure or device-related serious adverse events) was determined at 90 days (primary safety endpoint). A combination of adequate atrial capture threshold and sensing amplitude at three months was the first primary performance endpoint. The second primary performance endpoint was at least 70% atrioventricular synchrony at three months while the patient sat.

The study showed the following findings:

• Among the 300 patients enrolled, 190 had sinus-node dysfunction, and 100 had atrioventricular block as the primary pacing indication.
• The implantation procedure was successful (i.e., two functioning leadless pacemakers were implanted and had established implant-to-implant communication) in 98.3% of the patients.
• A total of 35 device- or procedure-related serious adverse events occurred in 29 patients.
• The primary safety endpoint was met in 271 patients, which exceeded the performance goal of 78%.
• The first primary performance endpoint was met in 90.2% of the patients, which exceeded the performance goal of 82.5%.
• The mean atrial capture threshold was 0.82 V, and the mean P-wave amplitude was 3.58±1.88 mV. None of the 21 patients (7%) with a P-wave amplitude of less than 1.0 mV required device revision for inadequate sensing.
• At least 70% atrioventricular synchrony was achieved in 97.3% of the patients, which exceeded the performance goal of 83%.

"The dual-chamber leadless pacemaker system met the primary safety endpoint and provided atrial pacing and reliable atrioventricular synchrony for three months after implantation," the researchers concluded.

Reference:

The study, "A Dual-Chamber Leadless Pacemaker," was published in the New England Journal of Medicine.