Left bundle branch pacing (LBBP) significantly reduced the composite of pacing-induced cardiomyopathy (PICM), hospitalization for heart failure (HF) and all-cause mortality in high pacing burden patients at high risk of cardiac dysfunction compared with right ventricular pacing (RVP), according to findings from the LBBP-FAVOUR trial presented at HRS 2026 and simultaneously published in JACC. Over an average follow-up period of 36 months, investigators noted this benefit was largely driven by the reduction in PICM risk.

Researchers randomized 160 patients from multiple centers in China in a 1:1 to ratio to either LBBP or RVP. The primary endpoint – a composite of all-cause mortality, HF hospitalization or PICM – occurred in nine patients in the LBBP group (11.6%) compared with 25 patients in the RVP group (33.9%). Broken down by event, PICM occurred in 6.5% of those assigned to LBBP vs. 18.2% in those assigned to RVP. No significant differences were observed in rates of all-cause mortality or HF hospitalizations.

In other findings, researchers observed "superior improvements" over the course of follow-up in LVEF, left ventricular end-diastolic diameter and left ventricular end-systolic diameter among those in the LBBP group compared with those in the RVP group. Additionally, more favorable NYHA functional class improvements were noted in the LBBP group.

"Although this study did not show significant differences between two pacing modalities with respect to [HF hospitalization] and mortality, the benefits of LBBP demonstrated in this study – including prevention of PICM and preservation of cardiac structure and function – in specific patient population, provide valuable clinical evidence for treatment decision-making in this high-risk population," say Nan Qiu, MB, and Xi Liu, MD, et al. "Furthermore, this work lays a solid foundation for future larger randomized trials powered for hard outcomes in specific patient populations to further validate these findings."