Left ventricular ejection fraction (LVEF) is more greatly improved by left bundle branch pacing (LBBP) cardiac resynchronization therapy (CRT) compared with biventricular pacing (BiVP)-CRT among patients with heart failure (HF) with nonischemic cardiomyopathy and left bundle branch block. These findings were published in the Journal of the American College of Cardiology.
Patients (N=40) with HF, nonischemic cardiomyopathy, and reduced LVEF were recruited at 2 sites in China between 2019 and 2021. Patients were randomly assigned in a 1:1 ratio to receive LBBP-CRT (n=20) or BiVP-CRT (n=20). The primary endpoint was the change in LVEF at 6 months.
The patients in the LBBP-CRT and BiVP-CRT cohorts were had a mean age of 62.3 [SD,11.2] and 65.3 [SD, 10.6] years, 65.0% and 35.0% were women, and LVEF was 28.3% [SD, 5.3%] and 31.1% [SD, 5.6%], respectively.
The left bundle branch pacing CRT procedure had a higher success rate (90%) than the BiVP-CRT procedure (80%). The LBBP-CRT intervention was also assoicated with a shorter procedure time (mean, 129.25 vs 155.92 min), time to implant lead (mean, 44.17 vs 55.50 min), and x-ray exposure (mean, 11.95 vs 18.66 min) compared with the BiVP-CRT intervention, respectively. The QRS duration was paced to 131.5 ms in the left bundle branch pacing CRT group and 136.6 ms in the BiVP-CRT group. Most patients in both groups received a cardiac resynchronization therapy with defibrillator device (70%-85%).
Two patients experienced a procedural complication, 1 left bundle branch pacingCRT recipient had a lead dislodgement and 1 BiVP-CRT recipient had pneumothorax.
The change in LVEF was 16.5% and 11.6% at 3 months and 21.1% and 15.6% at 6 months among the LBBP-CRT and BiVP-CRT cohorts, respectively. The adjusted mean difference from baseline between the 2 groups was 5.6% (95% CI, 0.3%-10.9%; P =.039) in the intention-to-treat analysis and 7.5% (95% CI, 2.0%-13.0%) in the per-protocol analysis, favoring left bundle branch pacing CRT.
For all echocardiography and cardiac function secondary endpoints, both groups had similar improvements but neither intervention strategy was favored over the other.
The major limitation of this study is the small sample size, which causes the study to be underpowered to detect significant differences in the secondary outcomes.
”This randomized pilot study of LBBP-CRT vs BiVP-CRT demonstrated the superiority of LBBP-CRT in LVEF improvement,” the study authors wrote. “Future larger, prospective randomized studies are needed to verify the long-term mortality benefits of LBBP-CRT.”
Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.
Wang Y, Zhu H, Hou X, et al; on behalf of the LBBP-RESYNC Investigators. Randomized trial of left bundle branch vs biventricular pacing for cardiac resynchronization therapy. J Am Coll Cardiol. Published online September 19, 2022. doi:10.1016/j.jacc.2022.07.019