Left Bundle-Branch Pacing Reduces Heart Failure Hospitalization vs Biventricular Pacing

Left bundle-branch pacing (LBBP) may offer a more effective alternative to conventional biventricular pacing (BiVP) for certain patients with heart failure, according to findings from a recent study.¹ The study found that LBBP significantly reduced the risk of death or heart failure hospitalization compared with BiVP in patients with left bundle-branch block (LBBB) and severely reduced left ventricular ejection fraction (LVEF).

This multicenter randomized clinical trial is published in JAMA Cardiology.

“The odds of a worse heart failure–related outcome were approximately 2-fold higher with CSP compared with BiVP, driven by a higher incidence of clinical events as well as a lesser improvement in LVEF,” wrote the researchers of the study.

Cardiac resynchronization therapy (CRT) is considered a first-line treatment for patients with heart failure and conduction abnormalities, helping restore coordinated ventricular contraction.² Traditionally, CRT is delivered through BiVP, which has been shown to improve cardiac function and reduce both HF hospitalizations and mortality. However, a substantial proportion of patients do not respond adequately to BiVP, highlighting the need for alternative pacing strategies for both initial treatment and rescue therapy. In recent years, CSP has emerged as a more physiologic approach to ventricular activation. CSP techniques—including His bundle pacing and LBBP—directly stimulate the heart’s native conduction pathways, potentially improving synchronization and clinical outcomes.

To evaluate whether LBBP could improve clinical outcomes, investigators conducted a multicenter, prospective, randomized clinical trial involving 200 patients treated at 6 medical centers in China.¹ Eligible participants had heart failure with an LVEF of 35% or less and evidence of LBBB. Patients were enrolled between October 2020 and March 2022 and randomly assigned in a 1:1 ratio to receive either LBBP or standard BiVP.

The trial’s primary end point was the time to death from any cause or hospitalization for heart failure. Secondary outcomes included all-cause mortality, heart failure hospitalization, and echocardiographic measures of cardiac function. Echocardiographic response was defined as an absolute increase in LVEF of at least 5%, while a super response was defined as an increase in LVEF of at least 15% or improvement to 50% or greater.

Among the 200 enrolled patients, 136 were male and 64 were female. The procedural success rate was high in both groups, occurring in 98% of patients receiving LBBP and 94% of those receiving BiVP, a difference that was not statistically significant.

Patients were followed for a median (IQR) of 36 (33-39) months. During this period, the primary outcome occurred significantly less often in the LBBP group. Only 8% of patients receiving LBBP experienced death or heart failure hospitalization compared with 28% of those treated with BiVP (HR, 0.26; 95% CI, 0.12-0.57; P < .001), indicating a substantial reduction in risk with LBBP.

Although overall mortality was numerically lower among patients receiving LBBP, the difference was not statistically significant. All-cause mortality occurred in 2% of patients in the LBBP group compared with 5% in the BiVP group (HR, 0.40; 95% CI, 0.08-2.04; P = .25).

The reduction in the primary outcome was largely driven by differences in heart failure hospitalizations. Hospitalization for heart failure occurred in 7% of patients treated with LBBP compared with 28% of those receiving BiVP. This represented a significant reduction in risk (HR, 0.23; 95% CI, 0.10-0.52; P < .001).

Improvements in cardiac function were observed in both treatment groups. Echocardiographic response rates were similar, occurring in 86% of patients receiving LBBP and 81% of those receiving BiVP. However, the proportion of patients experiencing a super response” was significantly higher in the LBBP group. More than half of patients treated with LBBP (55%) achieved this level of improvement compared with 36% of patients in the BiVP group (P < .007).

The findings suggest that conduction system pacing strategies such as LBBP may improve outcomes by restoring more physiologic ventricular activation compared with conventional CRT approaches. By directly stimulating the left bundle branch, LBBP may correct electrical dyssynchrony more effectively in patients with LBBB.

However, the researchers noted that additional studies are needed to confirm the findings and further define the role of LBBP in heart failure management. All participants were Chinese and included a relatively high proportion of patients with nonischemic cardiomyopathy, which may limit applicability to other populations or those with ischemic cardiomyopathy. Additionally, the study did not systematically assess left bundle branch capture during follow-up and lacked cardiac magnetic resonance imaging to evaluate myocardial scar burden, limiting insight into factors associated with LBBP failure or reduced efficacy.

Despite any limitations, the results provide growing clinical evidence supporting LBBP as a potential alternative to traditional BiVP in patients with heart failure, LBBB, and severely reduced ejection fraction.

“In this randomized clinical trial involving patients with HFrEF [reduced ejection fraction] and LVEF of 35% or less and LBBB, treatment with LBBP compared with BiVP yielded superior long-term outcomes. Further trials are warranted in this patient population,” wrote the researchers.

References

1. Chen X, Liu X, Li R, et al. Long-term outcomes of left bundle-branch pacing vs biventricular pacing in heart failure. JAMA Cardiol. doi:10.1001/jamacardio.2026.0083

2. Fu Y, Liu P, Jin L, et al. Left bundle branch area pacing: a promising modality for cardiac resynchronization therapy. Front Cardiovasc Med. 2022;9:901046. doi:10.3389/fcvm.2022.901046