First experience with leadless AAI(R) pacing in the Netherlands

Purpose

Since the CE-mark of the atrial leadless pacemaker (LP) in 2024, AAI(R) pacing using single LP in the atrium became possible. This offers an alternative for patients with sinus node dysfunction (SND), for whom transvenous DDD pacing is currently recommended but associated with unnecessary RV pacing, which may induce cardiomyopathy, and two leads increase complication risk. There was a shift in the guidelines in 2011 from AAI to DDD pacing for patients with SND, due to a 1.7% annual risk of developing AV conduction disturbances. The increased infection risk associated with reintervention in transvenous pacemakers further supported the recommendation for DDD pacing to avoid this additional risk.

However, with the rise of atrial LPs, with a lower infection risk, this rationale is shifting. The development of the atrial LP therefore allows for a re-evaluation of AAI(R) pacing in SND. This study evaluates the early outcomes of the atrial LP.

Methods

Ten patients received an atrial LP since October 2024. A Wenckebach point was assessed intraoperatively to evaluate AV node function. Patient characteristics, implant parameters, device settings, and longevity were analysed.

Results

Mean age was 62 years, four patients were female. All implants were succesful. In nine patients the pacing indication was SND. Six patients required mapping at different positions. Two patients needed refixation. Implant locations were the RA appendage base (n=6) and the RA lateral wall (n=4). Intraoperatively, mean threshold was 2.8V@0.64ms and 1.2V@0.5ms the next day. The mean impedance decreased during the first two weeks after implantation, but remained stable during the follow-ups. In one patient atrial thresholds could not be assessed intraoperatively due to atrial fibrillation. Mean total longevity was 9.3 years, depending on the pacing percentage, the pacing output, and the impedance. No complications occurred during a mean follow-up of 3.8 months (range 2–8 months); no patient required ventricular pacing.

Conclusion

Atrial (AAI(R)) leadless pacing appears to be a valuable option for SND patients. Early clinical outcomes show no complications and good device performance. A larger cohort is necessary to confirm these preliminary results. Continued follow-up is needed to evaluate long-term effects and device longevity.