LBBP + CSP Versus LBBP Alone for Cardiac Resynchronization Therapy

Official title

Left Bundle Branch Pacing + Coronary Sinus Pacing Versus Left Bundle Branch Pacing Alone for Cardiac Resynchronization Therapy in Patients Eligible for CRT-P A Randomized Crossover Pilot Clinical Trial

Overview

The purpose of this pilot clinical trial is to evaluate whether a novel cardiac resynchronization strategy, called LOT-CRT, is more effective than standard physiological pacing alone (LBBAP) in patients with heart failure. This is a randomized, single-center, crossover pilot study involving 10 patients. All participants will receive a specialized pacemaker (CRT-P) with leads implanted in two specific areas: the Left Bundle Branch Area (LBBAP) and the Coronary Sinus (CS). Because of the crossover design, each patient will serve as their own control, receiving two different pacing configurations in a random order: Active Phase (LOT-CRT): Simultaneous pacing of the left bundle branch and the coronary sinus. Control Phase (LBBAP alone): Pacing only the left bundle branch area. Each treatment phase will last 6 months, for a total follow-up of 12 months per patient. By testing both strategies in the same patient, this study will help clinicians identify the most effective way to restore heart synchrony and improve clinical outcomes in patients with advanced heart failure and conduction delays.

Detailed description

This is a single-center, randomized, crossover pilot clinical trial. Each patient will serve as their own control. Following the successful implantation of a device capable of stimulating the LBBAP and the coronary sinus, participants will be randomly assigned to one of two treatment sequences:

Sequence A: LOT-CRT (LBBAP + CS) for 6 months, followed by LBBAP alone Sequence B: LBBAP alone for 6 months, followed by LOT-CRT Each treatment phase will last 6 months, followed by an end-point evaluation and a crossover. Since the hemodynamic effect of electrical stimulation is immediate, no washout period is required between phases.

This study was designed as an exploratory pilot study; therefore, no formal sample size calculation was performed. The number of patients enrolled is considered adequate to assess the feasibility of the procedure, the safety of the crossover design, and to identify preliminary signals of clinical and electrical efficacy.

Interventions

• Device Left Bundle Branch Optimized CRT
  The CS lead will be implanted in a posterolateral or lateral vein using venography and standard IV delivery sheaths. Proper lead placement is confirmed by stable fixation, pacing capture, and absence of diaphragmatic pacing. The configuration for each phase of the study (LOT-CRT or LBBAP alone) will be assigned during randomization.
• Device Stimulation of the left bundle branch area (LBBAP)
  The LBBAP lead will be implanted via a transvenous approach using the C315His sheath, targeting the left bundle branch area in the right ventricular septum, ideally between the basal septum and the mid-septal region. Criteria for confirming successful LBBAP capture will include: * Evidence of narrowing of the stimulated QRS complex compared to baseline. * Right bundle branch block morphology on the ECG-stimulus-to-R-wave time in V6 \<80 ms (if available). * Low and stable pacing threshold (\<1

Primary outcome measures

• Compare the effects of the LOT-CRT strategy versus left bundle branch block pacing (LBBAP) alone in each patient, comparing baseline to the end of the study FEVI, quality of life and functional class by NYHA. [Time frame: 12 months]

Secondary outcome measures (9)

• Change in end-systolic diameter [Time frame: 12 months]
• QRS Duration [Time frame: 12 months]
• Change in end-diastolic diameter [Time frame: 12 months]
• NT-proBNP [Time frame: 12 months]
• Echocardiographic responder [Time frame: 12 months]
• Echocardiographic super-responder [Time frame: 12 months]
• Composite Clinical Outcome [Time frame: 12 months]
• Procedural parameters [Time frame: 12 months]
• Procedure Time/Fluoroscopy [Time frame: 12 months]

Eligibility criteria

Inclusion criteria

• Age ≥18 years
• Standard CRT-P indications according to ESC 2021 (EF ≤50%, QRS ≥130 ms, sinus rhythm or controlled AF)
• NYHA class II-IV
• Coronary venous anatomy suitable for placement of a coronary sinus electrode.
• Signed informed consent.
• Successful implantation of electrodes in the coronary sinus and in the left bundle branch area (LBBAP)

Exclusion criteria

• Concomitant indication for implantation of an implantable cardioverter-defibrillator (ICD) or CRT-D
• Significant uncorrected valvular disease or scheduled or anticipated cardiac surgery during the study period.
• Anatomical or technical contraindication for lead implantation in the coronary sinus or for lead implantation in the coronary sinus (such as sinus stenosis, coronary sinus branches unsuitable for cannulation, inability to advance and/or stabilize the lead, among others)
• Persistent atrial fibrillation with uncontrolled rate
• Comorbidities that may limit life expectancy to <1 year
• Participation in another clinical trial that could confound the evaluation of results within the last 6 months.
• Pregnancy or inadequate contraception
• In the researcher's opinion, the participant would not comply with the activities and visits outlined in the study protocol

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Crossover

Masking

Double blind

Primary purpose

Treatment

Study locations

Colombia · 1 center

• Clinica CardioVID — Medellín

Publications

• Upadhyay GA, Jastrzebski M, Foley P, Chandrasekaran B, Whinnett Z, Schaller RD, Gardas R, Richardson T, Moskal P, Kudlik D, Stadler RW, Zimmerman P, Burrell J, Waxman R, Cornelussen RN, Lyne J, Herweg B, Vijayaraman P. Echocardiographic response from left bundle branch area pacing optimized cardiac resynchronization therapy (LOT-CRT) vs traditional CRT. Heart Rhythm. 2025 Oct;22(10):2616-2624. doi PMID 40254116
• Chen X, Li X, Bai Y, Wang J, Qin S, Bai J, Wang W, Liang Y, Chen H, Su Y, Ge J. Electrical Resynchronization and Clinical Outcomes During Long-Term Follow-Up in Intraventricular Conduction Delay Patients Applied Left Bundle Branch Pacing-Optimized Cardiac Resynchronization Therapy. Circ Arrhythm Electrophysiol. 2023 Sep;16(9):e011761. doi: 10.1161/CIRCEP.122.011761. Epub 2023 Aug 14. PMID 37577815
• Parale C, Bootla D, Jain A, Satheesh S, Anantharaj A, Ahmed AS, Sukumaran SK, Balaguru S, Selvaraj R. Comparison of electrocardiographic parameters between left bundle optimized cardiac resynchronization therapy (LOT-CRT) and left bundle branch pacing-cardiac resynchronization therapy (LBBP-CRT). Pacing Clin Electrophysiol. 2023 Aug;46(8):840-847. doi: 10.1111/pace.14793. Epub 2023 Jul 21. PMID 37477545
• Jastrzebski M, Foley P, Chandrasekaran B, Whinnett Z, Vijayaraman P, Upadhyay GA, Schaller RD, Gardas R, Richardson T, Kudlik D, Stadler RW, Zimmerman P, Burrell J, Waxman R, Cornelussen RN, Lyne J, Herweg B. Multicenter Hemodynamic Assessment of the LOT-CRT Strategy: When Does Combining Left Bundle Branch Pacing and Coronary Venous Pacing Enhance Resynchronization?: Primary Results of the CSPOT S PMID 39440428
• Vijayaraman P. Left Bundle Branch Pacing Optimized Cardiac Resynchronization Therapy: A Novel Approach. JACC Clin Electrophysiol. 2021 Aug;7(8):1076-1078. doi: 10.1016/j.jacep.2021.04.005. Epub 2021 Jul 28. No abstract available. PMID 34332867
• Burri H, Jastrzebski M, Cano O, Curila K, de Pooter J, Huang W, Israel C, Joza J, Romero J, Vernooy K, Vijayaraman P, Whinnett Z, Zanon F. EHRA clinical consensus statement on conduction system pacing implantation: endorsed by the Asia Pacific Heart Rhythm Society (APHRS), Canadian Heart Rhythm Society (CHRS), and Latin American Heart Rhythm Society (LAHRS). Europace. 2023 Apr 15;25(4):1208-1236. PMID 37061848
• Glikson M, Burri H, Abdin A, Cano O, Curila K, De Pooter J, Diaz JC, Drossart I, Huang W, Israel CW, Jastrzebski M, Joza J, Karvonen J, Keene D, Leclercq C, Mullens W, Pujol-Lopez M, Rao A, Vernooy K, Vijayaraman P, Zanon F, Michowitz Y, Nielsen JC, Boersma L, Blomstrom-Lundqvist C, Kronborg MB, Chung MK, Tse HF, Khan HR, Leyva F, Rojel-Martinez U, Rucinski M, Varma N. European Society of Cardiolo PMID 40159278
• Jastrzebski M, Moskal P, Huybrechts W, Curila K, Sreekumar P, Rademakers LM, Ponnusamy SS, Herweg B, Sharma PS, Bednarek A, Rajzer M, Vijayaraman P. Left bundle branch-optimized cardiac resynchronization therapy (LOT-CRT): Results from an international LBBAP collaborative study group. Heart Rhythm. 2022 Jan;19(1):13-21. doi: 10.1016/j.hrthm.2021.07.057. Epub 2021 Jul 30. PMID 34339851

Identifiers

NCT: NCT07664189 · Clinica CardioVID · ERP -2025-14209

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗