Learning Curve Analyses for Left Bundle Branch Area Pacing with Conventional Stylet-Driven Pacing Leads

Stylet-driven leads compared with lumenless leads for left bundle branch area pacing: a systematic review and meta-analysis

OBJECTIVE

Left bundle branch area pacing (LBBAP) is a novel physiological pacing method for treating left ventricular dyssynchrony. LBBAP is often delivered using lumenless leads (LLL). However, recent studies have also reported the use of style-driven leads (SDL). This study is the first systematic review comparing the outcomes of LBBAP with SDL vs. LLL.

METHODS

The review and meta-analysis included all available comparative studies published on Embase, PubMed, Web of Science, CENTRAL, and Scopus up to 6th March 2024.

RESULTS

Eight observational studies were included in the review. Meta-analysis showed that success rates of LBBAP performed with LLL and SDL were comparable (OR: 1.72 95% CI: 0.94, 3.17 I2 = 38%). Duration of implantation and total procedural duration were significantly lower in LBBAP performed with SDL. The pacing threshold was significantly higher, while pacing impedance was significantly lower in the SDL compared to the LLL group. Pacing QRS interval, R-wave amplitude, and stimulus to peak left ventricular activation time were similar in the two groups. Intra-operative and post-operative dislodgement were significantly higher in the SDL group, but no difference was noted in intra-operative perforation and pneumothorax risk.

CONCLUSION

Limited evidence from observational studies with inherent selection bias shows that success rates for LBBAP may not differ between SDL and LLL. While implantation of SDL may be significantly faster, it carries a higher risk of lead dislodgement. Both SDL and LLL are associated with comparable pacing characteristics except for reduced pacing impedance with SDL.

Predictors of success in left bundle branch area pacing with stylet-driven pacing leads: a multicenter investigation

Purpose

Although left bundle branch area pacing (LBBAP) is an emerging conduction system pacing modality, it is unclear which parameters predict procedural success and how many implant attempts are acceptable. This study aimed to assess predictors of successful LBBAP, left bundle branch (LBB) capture, and factors associated with the number of LBBAP implant attempts.

Methods

This retrospective observational multicenter study was conducted in Korea. LBBAP was attempted in 119 patients; 89.3% of patients had bradyarrhythmia (atrioventricular block 82.4%), and 10.7% of patients had heart failure (cardiac resynchronization therapy) indication. Procedural success and electrophysiological and echocardiographic parameters were evaluated.

Results

The acute success rate of lead implantation in LBBAP was 95.8% (114 of 119 patients) and that of LBB capture was 82.4% (98 of 119 patients). Fewer implant attempts were associated with LBBAP success (three or fewer vs. over three times, p = 0.014) and LBB capture (three or fewer vs. over three times, p = 0.010). In the multivariate linear regression, the patients with intraventricular conduction delay (IVCD) required a greater number of attempts than those without IVCD [estimates = 2.33 (0.35-4.31), p = 0.02], and the larger the right atrial (RA) size, the more the attempts required for LBBAP lead implantation [estimates = 2.08 (1.20-2.97), p < 0.001].

Conclusion

An increase in the number of implant attempts was associated with LBBAP procedural failure and LBB capture failure. The electrocardiographic parameter IVCD and the echocardiographic parameter RA size may predict the procedural complexity and the number of lead implant attempts for LBBAP.

Stylet-driven Leads or Lumenless Leads for Conduction System Pacing

Stylet-driven leads have been recently introduced for conduction system pacing, while most of the previous experience has been obtained with lumenless leads. Design and structural characteristics of both lead types are significantly different, resulting in different implant techniques and independent learning curves. Lead performance appears to be comparable, whereas data on direct comparison of clinical outcomes are scarce. Currently, there are no specific clinical scenarios favouring the use of one lead type over another and the decision should rely on the individual experience of the implanter.

Conduction System Pacing: Hope, Challenges, and the Journey Forward

PURPOSE OF THE REVIEW

Cardiac pacing has evolved in recent years currently culminating in the specific stimulation of the cardiac conduction system (conduction system pacing, CSP). This review aims to provide a comprehensive overview of the available literature on CSP, focusing on a critical classification of studies comparing CSP with standard treatment in the two fields of pacing for bradycardia and cardiac resynchronization therapy in patients with heart failure. The article will also elaborate specific benefits and limitations associated with CSP modalities of His bundle pacing (HBP) and left bundle branch area pacing (LBBAP).

RECENT FINDINGS

Based on a growing number of observational studies for different indications of pacing therapy, both CSP modalities investigated are advantageous over standard treatment in terms of narrowing the paced QRS complex and preserving or improving left ventricular systolic function. Less consistent evidence exists with regard to the improvement of heart failure-related rehospitalization rates or mortality, and effect sizes vary between HBP and LBBAP. LBBAP is superior over HBP in terms of lead measurements and procedural duration. With regard to all reported outcomes, evidence from large scale randomized controlled clinical trials (RCT) is still scarce. CSP has the potential to sustainably improve patient care in cardiac pacing therapy if patients are appropriately selected and limitations are considered. With this review, we offer not only a summary of existing data, but also an outlook on probable future developments in the field, as well as a detailed summary of upcoming RCTs that provide insights into how the journey of CSP continues.

Utility of a guiding catheter for conduction system pacing: An early multicenter experience

Background

Conduction system pacing (CSP), either as His bundle pacing (HBP) or as left bundle branch area pacing (LBBAP), may be superior to right ventricular apical or septal pacing.

Objective

The study sought to present acute results for a new guiding catheter (Biotronik Selectra 3D) designed for CSP implantations of a retractable screw-in lead (Biotronik Solia S).

Methods

The primary endpoint of the prospective, international nonrandomized BIO|MASTER.Selectra 3D study was freedom from catheter-related serious adverse device effects (SADEs) within 1 week of lead implantation.

Results

Of 157 enrolled patients, CSP was achieved in 147 (93.6%) patients. No SADEs occurred within 7 days. LBBAP was achieved in 82 patients (45 as crossover from an HBP attempt) and HBP in 65 (44.2%) patients. In centers considering both HBP and LBBAP, the CSP implantation success approached 99%. Successful CSP implantations lasted on average ∼50 minutes (fluoroscopy ∼6 minutes). Most procedures (87.9%) needed only 1 catheter, even after switch from HBP to LBBAP. The catheter's handling was rated largely positive. In patients without bundle branch block, mean QRS duration increased from 106 ms (intrinsic) to 122 ms (CSP) (P = .001). In patients with bundle branch block, mean QRS duration decreased from 151 ms (intrinsic) to 137 ms (CSP) (P = .004).

Conclusion

The Selectra 3D catheter is a valuable tool for HBP and LBBAP implantations of the stylet-supported pacemaker leads. When implanters considered both HBP and LBBAP, the success rate was ∼99%. Flexibility to change between different approaches may be advisable in heterogeneous and challenging areas, such as CSP implantations.