Pacing Method Cuts Heart Failure Risk in Trial
Adults with atrioventricular block who need a pacemaker saw lower rates of serious events with left bundle-branch placement.
Updated on Nov. 9, 2026 in Heart Disease
In the OptimPacing trial, left bundle-branch pacing outperformed right ventricular pacing among nearly 700 people with atrioventricular block. An independent data monitoring committee recommended ending the trial early because of the difference.
Why it matters
For people who need a pacemaker to correct atrioventricular block, the choice of where the lead is placed in the heart may influence the risk of serious complications. The early stop suggests the finding was strong enough that continuing to randomize patients to the less favorable approach was no longer considered appropriate.
This randomized trial enrolled nearly 700 adults with atrioventricular block, with a mean age of 68 and about 58% men. Over a median follow-up of 35 months, left bundle-branch pacing was linked to a 59% lower risk of the combined primary outcome than right ventricular pacing, with pacing-induced cardiomyopathy seen in 0% of the left bundle-branch group versus 11.7% of the right ventricular group.
The players
OptimPacing trial
A randomized trial comparing two pacemaker lead placement strategies for atrioventricular block.
New England Journal of Medicine (NEJM)
A leading peer-reviewed medical journal that published the trial results alongside their presentation.
American Heart Association (AHA)
A major cardiovascular health organization whose 2026 scientific meeting hosted the presentation of the trial results.
The details
Pacemaker leads can be placed in different spots within the heart's electrical system to restore a normal rhythm. In this trial, the lead was positioned either along the left bundle-branch, a pathway that carries signals to the left side of the heart, or in the right ventricle, the more conventional placement. The lower event rate with left bundle-branch pacing was driven mainly by fewer heart failure hospitalizations and less pacing-induced cardiomyopathy, a weakening of the heart muscle that the stimulation itself can cause.
Timeline
Enrollment and tracking of nearly 700 patients took place over a five-year period.
Outcomes were compared over a median follow-up of 35 months.
Results were presented at AHA 2026 and published simultaneously in NEJM.
Health Landscape
Right ventricular pacing has long been the conventional default for patients with atrioventricular block who need a pacemaker. This trial provides randomized evidence that left bundle-branch pacing may reduce heart failure hospitalizations and pacing-induced cardiomyopathy compared with that default.
If you have been told you need a pacemaker for a heart rhythm problem, the placement of the lead may be worth asking about with your cardiologist. Symptoms such as worsening breathlessness or swelling could signal heart failure, which is worth reporting promptly to your doctor.
The takeaway
Lead placement may matter for long-term heart function in people who need pacing. Ask your cardiologist whether the approach used for your device reflects current evidence.
Further reading
For background on the conditions these devices treat, explore our Heart Disease coverage.
