OptimPacing trial: left bundle-branch pacing gave 8.5% vs 19.2% events at 4 years vs right ventricular
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.
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 nejm.org
New England Journal of Medicinenejm.orgOpen source ↗. The investigator-initiated, open-label study assigned 348 patients to left bundle-branch pacing and 354 to right ventricular pacing. The trial was stopped early on the recommendation of its data monitoring committee.
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.
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. The mean age was 68.4 years, and 57.5% of participants were men.
The primary outcome was a composite of death from any cause, hospitalization for heart failure, or pacing-induced cardiomyopathy nejm.org
New England Journal of Medicinenejm.orgOpen source ↗.
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.
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).
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) nejm.org
New England Journal of Medicinenejm.orgOpen source ↗.
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.
