Initial Experience of Left Bundle Branch Pacing using the Abbott Agilis HisPro Catheter with stylet-driven leads

Left bundle branch area pacing using a stylet-driven, retractable-helix lead: Short-term results from a prospective multicenter IDE trial (the BIO-CONDUCT study)

BACKGROUND

Left bundle branch area pacing (LBBAP) has swiftly emerged as a safe and effective alternative to right ventricular pacing. Limited data exist on the use of retractable-helix, stylet-driven leads for LBBAP.

OBJECTIVE

The objective of this study was to prospectively evaluate the performance and safety of a stylet-driven pacing lead in a rigorously controlled multicenter trial to support US market application.

METHODS

A multicenter, prospective, nonrandomized trial enrolled patients with standard pacing indications. Implant procedure and lead data, including threshold, sensing, impedance, and capture type, were collected through 3 months. Primary end points were freedom from LBBAP lead-related serious complications through 3 months and LBBAP implant success according to prespecified criteria. A blinded clinical events committee adjudicated all potential end point complications.

RESULTS

A total of 186 patients were included from 14 US sites. LBBAP implants were successful in 95.7% (178 of 186; 95% confidence interval 91.7%-98.1%; P < .0001 for comparison to the performance goal of 88%). Through the 3-month follow-up visit, 3 patients (1.7%) experienced a serious LBBAP complication (all lead dislodgments), resulting in a LBBAP lead-related complication-free rate of 98.3%. A total of 13 patients (7.8%) experienced any system- or procedure-related complication. The mean threshold was 0.89 V at 0.4 ms, the sensing value was 10.8 mV, and impedance was 608 Ω.

CONCLUSION

The short-term results from this prospective trial demonstrate both high implant success and freedom from LBBAP lead-related complications using this stylet-driven retractable helix lead. This trial supports the safety, use, and effectiveness of stylet-driven leads for performing contemporary physiologic pacing.

Cardiac resynchronization therapy-defibrillator implantation with shock lead placement in the left bundle branch area: a case report

Background

Cardiac resynchronization therapy (CRT) with biventricular pacing is a well-established therapy. Left bundle branch area pacing (LBBAP) is a safe technique providing physiological pacing, and LBBAP-optimized CRT (LOT-CRT) has been shown to provide better electrical resynchronization than traditional CRT. However, there are few reports on shock lead placement in the left bundle branch area (LBBA) during CRT-defibrillator (CRT-D) implantation.

Case summary

A 76-year-old woman with heart failure from dilated cardiomyopathy presented with left bundle branch block pattern (QRS duration, 160 ms). Left ventricular ejection fraction was 21%. Cardiac resynchronization therapy-defibrillator implantation was performed due to worsening symptoms. By reshaping the Agilis HisPro catheter and adding a septal curve, the shock lead was placed deep into the ventricular septum, narrowing QRS duration to 114 ms. Left ventricular activation time was 84 ms. A defibrillation threshold test confirmed successful treatment without adverse events. At 6-month follow-up, left ventricular ejection fraction improved from 21 to 63%, with the patient's condition improving from New York Heart Association class III to class I.

Discussion

It was reported that QRS narrowing in CRT was related to long-term mortality, and LOT-CRT further decreased QRS duration as compared with LBBP only or biventricular pacing and increased the response rate. Combining LBBAP with coronary sinus pacing can potentially achieve superior electrical resynchronization. Lack of a suitable tool for direct shock lead placement in LBBA necessitated additional LBBAP lead in conventional LOT-CRT. Our successful LOT-CRT-D procedure with minimal number of leads through Agilis HisPro catheter reshaping enabled direct LBBA shock lead placement.

Caveats related to conduction system pacing utilizing a proprietary deflectable mapping catheter with a stylet-driven lead

BACKGROUND

Hitherto, lumen less leads (LLLs) were routinely utilized for conduction system pacing (CSP). We report the largest experience using stylet-driven leads (SDLs) with a deflectable mapping catheter for CSP.

METHODS

Patients were prospectively and sequentially enrolled for CSP with SDL between June, 2021 and November, 2022 to (i) a novel deflectable mapping catheter (AgilisHisProTM, Abbott) (Group A) or (ii) a fixed curve sheath (Selectra3D, Biotronik) (Group B) in a 1:1 non-randomized fashion. The primary aim was to evaluate safety, feasibility, and efficacy of the CSP using SDL and deflectable mapping catheter (Group A) while reporting procedural success and intermediate-term follow-up.

RESULTS

Seventy-nine patients (59.4%M, mean age 67.2+/-10.6 years) were allocated to either (i) Group A (n = 40) or (ii) Group B (n = 39). In Group A (n = 40, 50% M, mean age 67.2+/-9.5 years, follow-up 210.7 + 25.1days), His bundle pacing (HBP) was the default strategy with left bundle branch area pacing (LBBaP) for bailout. Procedural success with HBP was feasible in 17/40 (42.5%) patients with remaining 23/40 (57.5%) needing LBBaP bailout. After initial learning curve, a manual septal curve was introduced to successfully aid LBBaP in 6/23 (26.1%) cases. Procedural and follow-up parameters did not differ significantly in HBP vs. LBBaP. Head-to-head comparison was not performed between the groups owing to different default protocols (HBP-Group A, Discretionary-Group B).

CONCLUSIONS

Use of SDL with single-curve deflectable mapping catheter was safe, feasible and yielded moderate procedural success with HBP and frequently needed a LBBaP bailout strategy. In approximately one-fourth of the latter, an out-of-plane manual septal curve was needed to optimize LBBaP.

Physiological pacing: just a lot of buzz or the next paradigm shift in bradycardia pacing?

ABSTRACT

Cardiac pacing has been an established therapy for bradyarrhythmia due to sinus or atrioventricular nodal disease since the 1950s. However, contemporary studies have shown that conventional right ventricular pacing (RVP) causes electromechanical dyssynchrony, which can lead to atrial fibrillation, heart failure and even death. Recently, the push for a more physiological cardiac pacing has seen a revival in the utilisation and development of conduction system pacing (CSP). There has been a shift towards adopting His bundle pacing (HBP) or left bundle branch area pacing (LBBaP) in bradycardia patients worldwide and in Singapore. This review serves to outline the electrophysiological concepts behind CSP and illustrate the different paced electrocardiogram characteristics of HBP, LBBaP and RVP to aid understanding of this revolutionary pacing approach among medical practitioners in Singapore.

Practical and systematic approach using the steerable catheter and stylet-driven lead to deliver safe and effective left bundle branch area pacing

INTRODUCTION

Current delivery tools were not designed for left bundle branch area pacing (LBBAP). Challenges using these tools include lack of reach into the right ventricle and poor support for the lead to penetrate the interventricular septum. Concerns using stylet-driven leads (SDL) for LBBAP have been previously highlighted. Knowledge and the technical know-how of using SDL for LBBAP need to be evaluated in a fair and consistent manner. A stepwise approach is devised for use of Agilis HisProTM steerable catheter with Tendril STS Model 2088TC lead for LBBAP and evaluated for safety and reproducibility.

METHODS

Consecutive patients undergoing LBBAP using the stepwise approach with Agilis HisProTM steerable catheter were analyzed. The safety, efficacy and reproducibility of the technique were evaluated. The lead parameters were analyzed in the immediate (1 day) and short-term period (3-6 months) post implantation.

RESULTS

LBBAP was attempted in 41 patients using the stepwise approach of which 37 (90.7%) were successful. The lead parameters were stable in the immediate and short-term post implantation in all our patients. There was no significant difference between the group of patients with multiple repositioning of the lead compared to those successful at the 1st attempt. There were no acute or short-term lead and procedural complications.

CONCLUSION

A stepwise and systematic approach using the Agilis HisProTM steerable catheter and proper handling of the Tendril STS Model 2088TC stylet-driven lead is an important part of the armamentarium to deliver LBBAP in a practical, effective and reproducible manner.

Left bundle branch area pacing in mildly reduced heart failure: A systematic literature review and meta-analysis

Cardiac resynchronization therapy (CRT) strategy for heart failure with mildly reduced ejection fraction (HFmrEF) is controversial. Left bundle branch area pacing (LBBAP) is an emerging pacing modality and an alternative option to CRT. This analysis aimed to perform a systematic review of the literature and meta-analysis on the impact of the LBBAP strategy in HFmrEF, with left ventricular ejection fraction (LVEF) between 35% and 50%. PubMed, Embase, and Cochrane Library were searched for full-text articles on LBBAP from inception to July 17, 2022. The outcomes of interest were QRS duration and LVEF at baseline and follow-up in mid-range heart failure. Data were extracted and summarized. A random-effect model incorporating the potential heterogeneity was used to synthesize the results. Out of 1065 articles, 8 met the inclusion criteria for 211 mid-range heart failure patients with an implant LBBAP across the 16 centers. The average implant success rate with lumenless pacing lead use was 91.3%, and 19 complications were reported among all 211 enrolled patients. During the average follow-up of 9.1 months, the average LVEF was 39.8% at baseline and 50.5% at follow-up (MD: 10.90%, 95% CI: 6.56-15.23, p < .01). Average QRS duration was 152.6 ms at baseline and 119.3 ms at follow-up (MD: -34.51 ms, 95% CI: -60.00 to -9.02, p < .01). LBBAP could significantly reduce QRS duration and improve systolic function in a patient with LVEF between 35% and 50%. Application of LBBAP as a CRT strategy for HFmrEF may be a viable option.

Initial experience with stylet-driven versus lumenless lead delivery systems for left bundle branch area pacing

INTRODUCTION

Left bundle branch area pacing (LBBP) has emerged as an alternative method for conduction system pacing. While initial experience with delivery systems for stylet-driven and lumenless lead implantation for LBBP has been described, data comparing outcomes of stylet-driven versus lumenless lead implantation for LBBP are limited. In this study, we compare success rates and outcomes of LBBP with stylet-driven versus lumenless lead delivery systems.

METHODS

Eighty-three consecutive patients (mean age 74.1 ± 11.2 years; 56 [68%] male) undergoing attempted LBBP at a single institution were identified. Cases were grouped by lead delivery systems used: stylet-driven (n = 53) or lumenless (n = 30). Baseline characteristics and procedural findings were recorded and compared between the cohorts. Intermediate term follow-up data on ventricular lead parameters were also compared.

RESULTS

Baseline characteristics were similar between groups. Successful LBBP was achieved in 77% of patients, with similar success rates between groups (76% in stylet-driven, 80% in lumenless, p = 0.79), and rates of adjudicated LBB capture and other paced QRS parameters were also similar. Compared with the lumenless group, the stylet-driven group had significantly shorter procedure times (90 ± 4 vs. 112 ± 31 min, p = 0.004) and fluoroscopy times (10 ± 5 vs. 15 ± 6 min, p = 0.003). Ventricular lead parameters at follow-up were similar, and rates of procedural complications and need for lead revision were low in both groups.

CONCLUSION

Delivery systems for stylet-driven and for lumenless leads for LBBP have comparable acute success rates. Long-term follow-up of lead performance following use of the various delivery systems is warranted.

Initial Experience with Left Bundle Branch Area Pacing in Patients with Atrioventricular Block and Impaired LV Function

Chronic right ventricular (RV) pacing can exacerbate heart failure in patients with a low left ventricular ejection fraction (LVEF). Left bundle branch area pacing (LBBAP) has emerged as a novel physiological pacing technique; however, information remains limited on its use among patients with a low EF. This study investigated the safety and short-term clinical outcomes of LBBAP among patients with impaired left ventricular (LV) function. This retrospective analysis of pacemakers at Chosun University Hospital, South Korea, included all patients with impaired LV function (EF<50%) who underwent pacemaker implantation for atrioventricular blockage from 2019-2022. Clinical characteristics, 12-lead electrocardiography findings, echocardiography findings, and laboratory parameters were evaluated. Composite outcomes were defined as all-cause mortality, cardiac death, and hospitalization due to heart failure during the 6-month follow-up. Altogether 57 patients (25 men; mean age, 77.4±10.8 y; LVEF, 41.5±3.8%) were divided into LBBAP (n=16), biventricular pacing (BVP; n=16), and conventional RV pacing (RVP; n=25) groups. In the LBBAP group, the mean paced QRS duration (pQRSd) was narrower (119.5±14.7 vs. 140.2±14.3 vs. 163.2±13.9; p<0.001) and cardiac troponin I level was elevated post-pacing (1.14±1.29 vs. 0.20±0.29 vs. 0.24±0.51, p=0.001). Lead parameters were stable. One patient was hospitalized, and four died (one patient each from heart failure admission, myocardial infarction, unexplained death, and pneumonia in RVP vs. one from intracerebral hemorrhage in BVP) during the follow-up period. In conclusion, LBBAP is feasible in patients with impaired LV function without acute or significant complications and provides a remarkably narrower pQRSd with a stable pacing threshold.