Left bundle-branch pacing was superior to right ventricular pacing in reducing the risk of death from any cause, heart failure (HF) hospitalization, or pacing-induced cardiomyopathy based on results from the international, multicenter OptimPacing trial, presented at AHA 2026 and simultaneously published in NEJM.

Researchers tracked nearly 700 men and women with atrioventricular block being treated with a pacemaker over a five-year period. Participants were randomized to either left bundle-branch pacing or right ventricular pacing. The mean age of patients was 68 years and roughly 58% were men.

Over the median follow-up period of 35 months, left bundle-branch pacing was associated with a 59% lower risk of death, HF hospitalization or cardiomyopathy compared right ventricular pacing. A primary outcome event occurred in 16 patients (8.5%) in the left bundle-branch pacing group compared with 35 patients (19.2%) in the right ventricular pacing group.

According to researchers, the lower incidence of a primary-outcome event with left bundle-branch pacing was primarily driven by a reduced incidence of HF hospitalizations and pacing-induced cardiomyopathy. No participants in the left bundle branch pacing group developed pacing-induced cardiomyopathy, compared with 11.7% in the right ventricular pacing group. HF hospitalization occurred in 1.5% of the left bundle branch pacing group vs. 2.9% of the right ventricular pacing group.

Given the superiority of left bundle-branch pacing, an independent data monitoring committee recommended ending the trial early.

“We expected that the group with left bundle branch pacing would do better than the group with right ventricular pacing,” said Jiangang Zou, MD, PhD. “However, the difference between the two groups was greater than we expected. This study shows that left bundle branch pacing should be the first choice for patients with heart block who need a pacemaker.”

Clinical Topics: Arrhythmias and Clinical EP, Cardiovascular Care Team, Heart Failure and Cardiomyopathies, Implantable Devices, EP Basic Science, Acute Heart Failure

Keywords: AHA Annual Scientific Sessions, AHA26, Atrioventricular Block, Cardiomyopathies, Heart Failure, Pacemaker, Artificial