His-bundle pacing vs biventricular pacing following atrioventricular nodal ablation in patients with atrial fibrillation and reduced ejection fraction: A multicenter, randomized, crossover study-The ALTERNATIVE-AF trial

BACKGROUND Atrioventricular nodal ablation (AVNA) combined with biventricular pacing (BVP) improves outcomes in patients with persistent atrial fibrillation (AF), adequate rate control, and reduced left ventricular ejection fraction (LVEF). His-bundle pacing (HBP) delivers physiological ventricular activation and is a promising alternative to BVP. OBJECTIVE The purpose of this trial was to compare HBP with BVP following AVNA. METHODS In this multicenter, prospective, randomized crossover trial, we recruited patients with persistent AF and reduced LVEF (<= 40%). All patients underwent AVNA and received both HBP and BVP. Patients were randomized to either HBP or BVP for 9 months (phase 1), then were switched to the alternative pacing modality for the next 9 months (phase 2). The primary endpoint was change in LVEF. RESULTS Fifty patients (age 64.3 +/- 10.3 years; ventricular rate 93.1 +/- 19.9 bpm; 72% male) were enrolled. Thirty-eight patients completed the 2 phases and were included in the crossover analysis. A significant improvement in LVEF was observed with HBP compared to BVP (phase 1: Delta LVEFHBP 21.3% and Delta LVEFBVP 16.7%; phase 2: Delta LVEFHBP 3.5% and Delta LVEFBVP -2.4%; P-generalized additive model - 0.015). Significant improvements in left ventricular end-diastolic diameter, New York Heart Association functional class, and B-type natriuretic peptide level were observed with both pacing modalities compared with baseline, whereas no significant differences were observed between HBP and BVP. CONCLUSION HBP delivers a modest but significant improvement in LVEF in patients with persistent AF, impaired ventricular function, and narrow QRS duration post-AVNA compared with BVP. Larger long-term trials are required to confirm the additional improvements in function with HBP.

Automated summary

This study compared the effects of His-bundle pacing (HBP) and biventricular pacing (BVP) in patients who underwent atrioventricular nodal ablation (AVNA). The results showed that HBP led to a significant improvement in left ventricular ejection fraction (LVEF) compared to BVP. Both pacing modalities had similar effects on improving left ventricular end-diastolic diameter, functional class, and B-type natriuretic peptide level.