Distance From Pacing Lead Tip to Left Ventricular Cavity Predicts Long-term Loss of Left Bundle Branch Capture:
Mengxing Cai1, Yuanhao Qiu2, Yuanning Xu3
1State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Xicheng District, Beijing, China.
Insights
Left bundle branch (LBB) pacing offers physiological activation, but long-term capture can be lost. A lead tip to left ventricular cavity distance greater than 2 mm at mid-term predicts this loss, emphasizing optimal lead placement for durable pacing.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- Left bundle branch (LBB) pacing (LBBP) is an emerging technique for cardiac pacing that preserves physiological activation.
- Limited data exist on the long-term durability of conduction system capture with LBBP.
Purpose of the Study:
- To assess the long-term stability of LBBP capture.
- To identify predictors of LBB capture loss over time.
Main Methods:
- Analysis of the prospective, multicentre IMAGE-LBBP cohort.
- Inclusion of 34 patients with confirmed LBBP and analyzable mid-term imaging.
- Prospective collection of data on lead complications and pacing parameters, with the main outcome being new-onset LBB capture loss after mid-term assessment.
Main Results:
- During a mean follow-up of 60.1 months, 20.6% of patients experienced new-onset LBB capture loss.
- Mid-term lead tip to left ventricular cavity (Tip-LV) distance was an independent predictor of long-term capture loss (HR, 2.26; P = 0.015).
- A Tip-LV distance > 2 mm predicted capture loss with high accuracy (AUC, 0.881), significantly increasing the risk (HR, 7.4; P = 0.012).
Conclusions:
- LBB capture loss is a progressive complication occurring in approximately 20% of patients long-term.
- A mid-term Tip-LV distance > 2 mm is a strong predictor of subsequent capture loss.
- Optimal lead implantation and mid-term anatomical assessment are crucial for ensuring durable conduction system pacing.
Background:
Left bundle branch (LBB) pacing (LBBP) has been an emerging pacing modality that preserves physiological activation. However, data on the long-term durability of conduction system capture remain limited. In this study we aimed to assess the long-term stability of LBBP capture and identify predictors of capture loss.
Methods:
We analyzed data from the multicentre, prospective Image Location and Performance of Left Bundle Branch Pacing (IMAGE-LBBP) cohort. Of 50 patients with bradycardia who underwent mid-term cardiac computed tomography imaging after left bundle branch area pacing implantation, 34 with confirmed LBBP and analyzable imaging at mid-term were included in the long-term analysis. Data on lead-related complications and pacing parameters were prospectively collected. The main outcome was new-onset loss of LBB capture after the mid-term assessment.
Results:
During a mean follow-up of 60.1 ± 7.9 months, new-onset LBB capture loss occurred in 20.6% (7/34) of patients. Multivariate Cox regression identified mid-term lead tip to left ventricular cavity (Tip-LV) distance as an independent predictor of long-term capture loss (hazard ratio, 2.26; 95% confidence interval [CI], 1.17-4.35; P = 0.015). A cutoff of 2.0 mm yielded high predictive accuracy (area under the receiver operating characteristic curve, 0.881; 95% CI, 0.756-1.0), with 85.7% sensitivity and 77.8% specificity. Kaplan-Meier analysis showed a significantly greater risk of capture loss in patients with a Tip-LV distance > 2 mm compared with those with ≤ 2 mm (hazard ratio, 7.4; 95% CI, 1.6-34.8; log rank P = 0.012).
Conclusions:
LBB capture loss is progressive and occurs in approximately 20% of patients during long-term follow-up. A Tip-LV distance > 2 mm at mid-term is strongly associated with subsequent capture loss, highlighting the importance of optimal lead implantation and mid-term anatomical assessment to ensure durable conduction system pacing.
Clinical Trial Registration:
NCT04119323.
