New pacing method cuts cardiac risk 59%

A 17-center randomized trial offers new evidence for choosing pacemaker techniques in heart block.

By
Teraya Smith
November 11, 2026
3 min

MDSpire News

Overview

In the randomized OptimPacing trial, left bundle-branch pacing (LBBP) was associated with a lower incidence of the composite of death, heart failure hospitalization, or pacing-induced cardiomyopathy than right ventricular pacing (RVP) among patients with atrioventricular block. The estimated 4-year incidence was 8.5% with LBBP and 19.2% with RVP, a reported 59% relative risk reduction; investigators cautioned that early trial termination could overestimate benefit.

Background

Patients with atrioventricular block may require substantial ventricular pacing, and conventional RVP can disrupt ventricular synchrony. LBBP engages the heart’s native electrical conduction system to promote coordinated ventricular contraction. OptimPacing compared these approaches in adults expected to require ventricular pacing at least 20% of the time. The trial’s findings were presented at the American Heart Association Scientific Sessions 2026 and published simultaneously in the New England Journal of Medicine.

Data Highlights

Outcome	Left bundle-branch pacing	Right ventricular pacing
Patients in modified intention-to-treat analysis	342	343
Primary composite events	16	35
Estimated 4-year composite incidence	8.5%	19.2%
Pacing-induced cardiomyopathy events	0	19
Estimated 4-year incidence of pacing-induced cardiomyopathy	0%	11.7%
Heart failure hospitalization as first event	2 (estimated incidence 1.5%)	7 (estimated incidence 2.9%)
All-cause deaths	15	13
Procedure-related complications	3.8%	3.2%

Key Findings

OptimPacing was an investigator-initiated, open-label randomized trial conducted at 17 centers in five countries between June 2021 and January 2025.
Of 702 randomized patients, 685 were included in the modified intention-to-treat analysis; mean age was 68.4 years, 57.5% were men, and most had preserved left ventricular ejection fraction at baseline.
After a median follow-up of 35.1 months, the primary composite outcome occurred in 16 patients assigned to LBBP and 35 assigned to RVP; the difference met the prespecified superiority threshold.
Pacing-induced cardiomyopathy occurred in no LBBP patients and 19 RVP patients; estimated 4-year incidences were 0% and 11.7%, respectively.
All-cause mortality was similar between groups (15 deaths with LBBP and 13 with RVP), as were procedure-related complication rates (3.8% and 3.2%).
The independent monitoring committee recommended early termination after the superiority threshold was met. Investigators cautioned that early termination could overestimate benefit; the predominance of patients with preserved ventricular function and use of one lead type for all LBBP procedures limit generalizability.

Clinical Implications

The trial provides randomized comparative evidence for LBBP versus RVP in patients with atrioventricular block who are expected to require frequent ventricular pacing. Its findings should be interpreted in light of early termination, the largely preserved baseline ejection fraction, and use of a single lead type; the supplied context does not establish outcomes in patients with reduced ejection fraction or with other pacing devices.

Conclusion

In OptimPacing, LBBP was associated with fewer primary composite events than RVP, driven in part by fewer cases of pacing-induced cardiomyopathy. Mortality was similar, and the trial’s limitations warrant caution when applying the results beyond the studied population and procedure.