# Long-term benefits of single left ventricular pacing based on rate-adaptive atrioventricular delay algorithm in cardiac resynchronization therapy

## TL;DR

A study finds that single left ventricular pacing with a rate-adaptive algorithm offers better long-term outcomes than standard biventricular pacing in heart therapy.

## Contribution

This study provides long-term evidence showing clinical superiority of rate-adaptive atrioventricular delay-guided left ventricular pacing over biventricular pacing in cardiac resynchronization therapy.

## Key findings

- RAAVD-guided LUVP reduced rehospitalization rates and device complications compared to BVP.
- RAAVD LUVP extended battery longevity and improved cardiac function and structure.
- Left bundle branch area pacing enhanced interventricular synchrony compared to lateral vein pacing.

## Abstract

Current guidelines lack long-term evidence comparing single left ventricular pacing (LUVP) with standard biventricular pacing (BVP) in cardiac resynchronization therapy (CRT). This study evaluates the clinical superiority of rate-adaptive atrioventricular delay (RAAVD) algorithm-guided LUVP over BVP.

In this retrospective cohort study, 67 consecutive patients meeting the criteria for cardiac resynchronization therapy (CRT) with complete left bundle branch block (CLBBB) were enrolled between April 2013 and April 2023. They were assigned to either the right atrium-left ventricle dual-site pacing group (RAAVD LUVP, n = 42) or the biventricular pacing group (BVP, n = 25), with a median follow-up duration of 43.59 months. The primary endpoints included disease-related rehospitalization, device complications, and battery longevity. Secondary outcomes comprised cardiac structure, function, and synchrony.

There were no significant differences in baseline characteristics such as preoperative ejection fraction and cardiomyopathy type between the groups. The RAAVD LUVP group demonstrated significant advantages: i) Rehospitalization rate (23.8% vs. 48.0%, P = 0.041); ii) Zero device complications vs. 12% in BVP (P = 0.048), iii) Extended battery longevity (7.95 ± 0.78 vs. 4.66 ± 0.66 years, P < 0.001); iv) Cardiac function (LVEF: 45.7 ± 13.3% vs. 38.9 ± 10.6%, P = 0.034; The 6-minute walk distance: 414.50 ± 68.79 m vs. 379.04 ± 58.02 m; P = 0.034); v) Cardiac structure (LAD: 35.55 ± 7.11 mm vs. 39.96 ± 8.25 mm, P = 0.018; LVEDd: 60.10 ± 10.85 mm vs. 67.68 ± 9.40 mm, P = 0.01), and vi) Cardiac synchronization (paced QRS duration: 129.00 ± 18.78 vs. 147.96 ± 26.13 ms, P = 0.001; Ts-SD12: 96.66 ± 51.51 ms vs. 122.12 ± 52.29 ms; P = 0.034). Subgroup analysis revealed left bundle branch area pacing (LBBAP) further enhanced interventricular synchrony compared to lateral vein pacing (IVMD: 37.74 ± 21.24 vs. 53.11 ± 19.42 ms, P = 0.020).

The dynamic integration of RAAVD LUVP with intrinsic conduction brings CRT closer to physiological states, which provides sustained clinical benefits compared to conventional BVP. The additional electromechanical advantages of LBBAP are related to the choice of anatomical location.