Long-term follow up of single-chamber atrial pacing-system upgrade and Wenckebach block point behavior: potential implications for leadless AAI pacing?

BACKGROUND

Single chamber atrial pacing (AAI) provides a disease-specific treatment for sick sinus syndrome (SSS) but has largely been replaced by DDD pacing. With the advent of leadless atrial pacemakers (PM), there is growing interest in long-term follow-up data in patients with SSS and an AAI pacemaker.

PURPOSE: To assess the incidence of system upgrade in patients treated with AAI-PM for SSS during long-term follow-up.

METHODS

This is an analysis of prospectively enrolled patients undergoing implantation of an AAI-PM. Wenckebach block point (WBP) was measured at implantation and serially during follow up.

RESULTS

We included 178 patients (58% female, median age at implantation 77 [71-83] years). The median follow-up duration was 6.5 [2.0-9.7] years. Twenty-three patients (13%) received a system upgrade to a DDD system, corresponding to a yearly upgrade rate of 2.0%. Median time to system upgrade was 5.2 [1.6-8.7] years. Reasons for system upgrade were higher-degree AVB (39%), atrial arrhythmias (35%), low WBP (17%), and syncope (9%). Median WBP at implantation was 130 [120-140] bpm, showing a significant decline over time in the upgrade-group compared to the rest of the cohort with 103 [91-130] bpm vs. 130 [120-130] bpm (p = 0.011).

CONCLUSION

In this cohort of patients undergoing AAI-PM implantation for SSS, upgrade to a DDD system was low during long-term follow-up. Therefore, AAI pacing for the treatment of SSS may be considered a patient-tailored treatment option, especially in light of novel leadless pacing therapies.