Cardiac pacing strategies and post-implantation risk of atrial fibrillation and heart failure events in sinus node dysfunction patients: a collaborative analysis of over 6000 patients.

Background: Pacing-modes selection in sinus-node-dysfunction (SND) patients continues to be a subject of debate. Atrial fibrillation (AF) and cardiac dysfunction remain significant problems following cardiac-pacing therapy. Prevention of these complications is of clinical relevance.

Methods: We performed a collaborative pooled-analysis of randomized trials (RCT) to evaluate the effect of currently available pacing strategies on the risk of post-implantation AF and heart failure events (HF) in SND patients. The primary endpoint was a composite AF and HF events.

Results: Ten RCTs (n = 6639, male 57 %, median follow-up 2.5 years) were included. The pooled-analysis was stratified into two subsets [single chamber atrial pacing (AAI) vs. dual chamber pacing (DDD), and minimal ventricular pacing (MinVP) vs. DDD]. No significant difference was observed in the AAI vs. DDD subset regarding the primary outcome (P = 0.83). Notably, the mean percentage of ventricular-pacing in the MinVP group was 6.5 vs. 77.4 % in the DDD group (P < 0.05), and MinVP was associated with a substantially reduced risk of composite AF and HF (OR 0.66, P = 0.007) in patients receiving pacemaker as primary treatment. However, in the long-term paced patients scheduled for device replacement, there was no significant difference in the rate of primary endpoint between MinVP vs. DDD groups (P > 0.05).

Conclusions: These results support MinVP over conventional DDD for SND patients who received pacemaker as primary treatment in improving the clinical outcome. For patients who already had chronic ventricular-pacing and impaired cardiac function, a device update to MinVP algorithm may exert no favorable effect on the cardiac performance.