Safety, Efficacy, and Functional Outcomes Using a Novel Small-Diameter Defibrillation Lead for LBBAP: Final Results of LEADR LBBAP

Authors, Journal, Affiliations, Type, DOI

• Authors: Pugazhendhi Vijayaraman, Pamela K. Mason, Xingbin Liu, Marek Jastrzebski, Russell Denman, Edward J. Schloss, Zachary I. Whinnett, Jordana Kron, Azlan Hussin, John S. Zakaib, François Philippon, Muhammad Afzal, Parash Pokharel, Travis D. Richardson, James Burrell, Jocelyn Tanner, Robert W. Stadler, Tessa Geelen, Kiah Butler, George H. Crossley III, on behalf of the LEADR LBBAP Trial Investigators
• Journal: Heart Rhythm 2026 (online ahead of print)
• Affiliations: Geisinger Heart Institute; University of Virginia; West China Hospital, Sichuan University; Jagiellonian University; The Prince Charles Hospital (Brisbane); The Christ Hospital (Cincinnati); Imperial College Healthcare NHS Trust; VCU; Institut Jantung Negara (Kuala Lumpur); Minneapolis Heart Institute Foundation; Institut Universitaire de Cardiologie et de Pneumologie de Québec, Laval University; Ohio State University; Vanderbilt Heart & Vascular Institute; Medtronic (Mounds View, MN and Bakken Research Center, Maastricht)
• Type: Prospective, single-arm, non-randomised, global clinical trial (NCT04863664)
• DOI: 10.1016/j.hrthm.2026.08.030

Overview

LEADR LBBAP evaluated the 4.7-F, lumenless, catheter-delivered, integrated bipolar, single-coil OmniaSecure defibrillation lead (Medtronic) when implanted in the left bundle branch area. Of 316 implantation attempts, 302 (95.6%) succeeded; 157 patients received LBBAP-ICD therapy and 143 received LBBAP-optimized CRT (LOT-CRT). Over a mean follow-up of 9.9 months, electrical performance was stable (pacing threshold, impedance and R-wave amplitude), freedom from study lead–related major complications was 97.7% at 6 months and 96.8% at 12 months, and appropriate therapy was delivered in 7.9% of patients at 1 year with a 2.1% inappropriate-shock rate. In the LOT-CRT subgroup, QRS narrowed from 170.6 to 157.5 ms, LVEF rose from 29.7% to 38.1%, LVESVi fell from 53.8 to 40.5 mL/m², and KCCQ improved by 14.2 points at 6 months. The trial supports a single-lead strategy that provides defibrillation and physiological pacing without a separate RV pace/sense lead.

Keywords

Conduction system pacing; Left bundle branch area pacing; Defibrillation lead; Cardiac resynchronization

Key Takeaways

Study design and population

• Prospective, single-arm, non-randomised, global trial at 25 sites; 332 enrolled, 316 attempted, 302 successfully implanted per protocol.
• Mean age 64.9 ± 12.2 years; 29.1% women.
• Two treatment groups: LBBAP-ICD (n = 157; 51 single-chamber, 106 dual-chamber) and LOT-CRT (n = 143; all CRT-D).
• Guideline indications for primary or secondary prevention ICD or CRT-D; CRT-D patients also required a coronary sinus lead for LOT-CRT.
• Mean follow-up 9.9 ± 4.0 months.
• Baseline: LBBB 14.0% in the ICD group vs 72.7% in LOT-CRT; IVCD 10.2% vs 9.8%; RBBB 12.7% vs 10.5%; LVEF not reported as a group mean but LOT-CRT baseline 29.7%.

Implantation and electrical performance

• LBBAP success per protocol: 302/316 (95.6%).
• Defibrillation success at implantation: 100% (previously reported).
• Pacing capture threshold, R-wave amplitude and impedance remained stable through 12 months.
• No adverse events related to anodal stimulation during pacing.
• Capture criteria used (not mutually exclusive): terminal R/r in V1 plus V6/V5 RWPT <100 ms (66.6%); sheath ventriculography (56.0%); V6–V1 interpeak >33 ms (24.8%); diagnostic QRS transition (18.2%); LBB potential (7.9%).

Safety

• Freedom from study lead–related major complications: 98.0% at 3 months, 97.7% at 6 months, 96.8% at 12 months.
• Eight major complications in eight patients: four lead dislodgements (all within 90 days), one device connection issue (day 75), one high RV threshold (day 92), one undersensing at implantation, one Twiddler syndrome (day 344).
• Seven leads explanted; median dwell time 49 days (range 20–352).
• Eight deaths; none adjudicated as causally related to the lead, system or procedure.
• No septal perforation, oversensing or helix/lead fracture major complications.

Arrhythmia therapy

• 83 appropriately treated VT/VF episodes in 21 patients.
• Shocks delivered in 19 episodes (11 patients); successful termination in 89.5% (17/19).
• ATP delivered for 69 monomorphic VT episodes in 16 patients; GEE-model ATP efficacy 90.0% (95% CI 80.6%–95.2%).
• Appropriate therapy at 1 year: 7.9% (95% CI 5.2%–12.1%); appropriate shocks 4.0%, ATP 6.5%.
• Inappropriate shocks: 2.1% (95% CI 0.9%–4.6%), mostly atrial fibrillation/flutter.

LOT-CRT functional outcomes (n = 143)

• QRS duration: 170.6 ± 29.8 → 157.5 ± 21.9 ms at 6 months (P < .001).
• LVEF: 29.7% ± 6.3% → 38.1% ± 7.9% (+8.5 points; P < .001).
• LVESVi: 53.8 ± 27.1 → 40.5 ± 29.3 mL/m² (P < .001).
• KCCQ: 66.7 ± 22.4 → 81.5 ± 17.6 points (+14.2; P < .001).
• Clinical composite score improved or stabilised in 85.2%.
• CRT response (LVEF gain ≥5% and/or LVESVi reduction ≥15%): 82%.
• LBBB subgroup (n = 104): QRS 175.2 → 156.6 ms (P < .001); LVEF 29.8% → 38.6%; LVESVi 55.2 → 39.2 mL/m².
• Non-LBBB subgroup (n = 39): QRS 159.6 → 160.1 ms (P = .511); LVEF 29.2% → 36.2%; LVESVi change not significant (P = .084).

Interpretation

• A single 4.7-F lumenless defibrillation lead can deliver both defibrillation and LBBAP, potentially reducing hardware, infection risk and tricuspid interference.
• Smaller lead diameter may reduce mechanical interference with tricuspid leaflet coaptation (computational modelling cited).
• The LOT-CRT results support adding a coronary sinus lead when LBBAP alone does not fully resynchronise, including in non-LBBB patients (LVEF improved even when QRS did not).

Limitations of the document

• Single-arm, non-randomised, non-comparative — no direct comparison with standard RV defibrillation leads or with BVP.
• Short mean follow-up (<1 year) and modest sample; long-term lead durability is unknown.
• LOT-CRT was not compared with BVP, so its incremental benefit cannot be estimated from this trial.
• LBBAP capture quality was not centrally adjudicated; success was physician-reported per protocol, and the quality of left bundle capture was not a primary objective.
• Post-hoc analyses of appropriate/inappropriate therapy, CRT response and LBBB vs non-LBBB subgroups were not prespecified.
• Industry sponsorship: Medtronic funded the trial and employs several authors; multiple investigators report Medtronic honoraria and consultancy.
• Defibrillation testing was not routine; shock efficacy is probabilistic and long-term shock failure will be monitored in the LEADR PAS registry.

Key Concepts Mentioned

• concepts/Left-Bundle-Branch-Area-Pacing — the pacing strategy
• concepts/LOT-CRT — LBBAP plus coronary sinus LV pacing
• entities/ICD — the device platform
• concepts/Cardiac-Resynchronization-Therapy — the CRT-D indication
• entities/ICD — ATP delivered through the LBBA lead
• entities/ICD — the novel lead technology

Key Entities Mentioned

• Medtronic — manufacturer and sponsor; OmniaSecure defibrillation lead
• LEADR LBBAP Trial Investigators — multicentre trial group
• Geisinger Heart Institute — coordinating centre

Wiki Pages Updated

• Created: wiki/sources/leadr-lbbap-hrs-2025.md
• Updated: wiki/entities/ICD.md
• Updated: wiki/concepts/Left-Bundle-Branch-Area-Pacing.md
• Updated: wiki/concepts/LOT-CRT.md
• Updated: wiki/sourceindex.md
• Updated: log.md