# OptimPacing trial: left bundle-branch pacing gave 8.5% vs 19.2% events at 4 years vs right ventricular

- Published: 2026-11-12 04:02 UTC
- Section: Life & Health › Medicine
- Tags: left bundle-branch pacing, right ventricular pacing, atrioventricular block, pacing-induced cardiomyopathy, OptimPacing trial, heart failure hospitalization, pacemaker randomized trial, cardiac dyssynchrony
- URL: https://realtech.media/news/rt-eac3ae779f7ec3f2ec0ebf94_optimpacing_trial_left/

**In a randomized trial of 685 analyzed patients with atrioventricular block, left bundle-branch pacing was linked to fewer deaths, heart-failure admissions and pacing-induced cardiomyopathy than right ventricular pacing.**

![OptimPacing trial: left bundle-branch pacing gave 8.5% vs 19.2% events at 4 years vs right ventricular](https://realtech.media/media/2026/11/1c7f4986ff6136d7.jpg)
*Brian Adducci, Wikimedia Commons, CC BY-SA 4.0*

An international randomized trial, OptimPacing, compared left bundle-branch pacing with right ventricular pacing in 702 patients with atrioventricular block, according to a report in the New England Journal of Medicine [1]. The investigator-initiated, open-label study assigned 348 patients to left bundle-branch pacing and 354 to right ventricular pacing [1]. The trial was stopped early on the recommendation of its data monitoring committee [1].

## Design and patients

Right ventricular pacing is associated with cardiac dyssynchrony and left ventricular systolic dysfunction. Left bundle-branch pacing preserves electrical and mechanical synchrony of the left ventricle, but its clinical benefits relative to right ventricular pacing in atrioventricular block had remained unclear [1].

Patients were assigned in a 1:1 ratio. Seventeen of them (6 in the left bundle-branch group and 11 in the right ventricular group) were excluded before device implantation. The modified intention-to-treat analysis included 685 patients: 342 in the left bundle-branch group and 343 in the right ventricular group [1]. The mean age was 68.4 years, and 57.5% of participants were men [1].

The primary outcome was a composite of death from any cause, hospitalization for heart failure, or pacing-induced cardiomyopathy [1].

## Results and safety

At the prespecified interim analysis, the data monitoring committee recommended early termination of the trial. At a median follow-up of 35.1 months (interquartile range, 23.6 to 40.7), a primary-outcome event had occurred in 16 patients with left bundle-branch pacing and in 35 patients with right ventricular pacing [1].

The Kaplan-Meier 4-year cumulative incidence was 8.5% and 19.2%, respectively. The hazard ratio was 0.41 (95% confidence interval, 0.23 to 0.75; P = 0.003 by a stratified log-rank test) [1].

Serious adverse events unrelated to implantation procedures occurred in 39 patients (11.8%) who received left bundle-branch pacing and in 33 patients (9.3%) who received right ventricular pacing (P = 0.32) [1].

The authors concluded that, among patients with atrioventricular block, left bundle-branch pacing was superior to right ventricular pacing in reducing the risk of the composite of death from any cause, hospitalization for heart failure, or pacing-induced cardiomyopathy [1].

## Sources

1. [New England Journal of Medicine](https://doi.org/10.1056/NEJMoa2612972)
2. [knowridge.com](https://knowridge.com/2026/11/pacemakers-that-follow-the-hearts-wiring-reduced-serious-heart-problems)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-eac3ae779f7ec3f2ec0ebf94_optimpacing_trial_left/