Clinical Efficacy of Early Left Bundle Branch Pacing for Cardiac Resynchronization Therapy (Early-RESYNC)

Clinical Efficacy of Early Left Bundle Branch Pacing for Cardiac Resynchronization Therapy Compared With Guideline-directed Medical Therapy in Heart Failure With Mild-reduced Ejection Fraction.

This is a two-center, prospective randomized controlled trial. The aim of this study is to compare the clinical efficacy of early left bundle branch pacing for cardiac resynchronization therapy and guideline-directed medical therapy in heart failure with mild-reduced ejection fraction.

Study Overview

• Status: Active, not recruiting
• Conditions: Heart Failure; Left Bundle Branch Pacing
• Intervention / Treatment: Device: LBBP+GDMT; Drug: GDMT

Detailed Description

Early-resync is a two-center, prospective randomized controlled trial that is designed to determine whether early left bundle branch pacing has a better impact on LV function improvement as compared with traditional guideline-directed medical therapy in heart failure with mild-reduced ejection fraction（36%≤LVEF≤50%） and complete left bundle branch block (CLBBB). Patients with symptomatic heart failure,36%≤LVEF≤50%, NYHA function class II-IV, and CLBBB（according to STRAUSS criteria) will be 1:1 randomized to LBBP+GDMT or GDMT group after enrollment and be followed at 3 and 6 months after randomization. LBBP will be performed by a double-chamber device in LBBP+GDMT group. All patients will receive GDMT. The primary endpoint is the change in the LVEF at 6 months after randomization from baseline.

• Study Type: Interventional
• Enrollment (Estimated): 36
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100037
      • Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences
  • Jiangsu
    • Nanjing, Jiangsu, China
      • The First Affiliated Hospital of Nanjing Medical University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Age ≥ 18 years;
2. symptomatic heart failure despite guideline-directed medical therapy for at least 3 months, NYHA class II-IV, with an EF between 35% and 50%;
3. complete LBBB meeting Strauss's standard definition
4. Signed informed consent.

Exclusion Criteria:

1. Expected survival less than 24 months;
2. Indicated for ICD or pacing therapy;
3. History of VT, VF, or hemodynamic instability;
4. History of mechanical tricuspid valve replacement;
5. Ischemic cardiomyopathy scheduled for CABG and PCI within 3 months;
6. Severe structural heart disease may necessitate cardiac surgery or heart transplantation within 1 year;
7. Pregnancy or planning for pregnancy;
8. Hypertrophic cardiomyopathy or those underwent ventricular septal defect repair, in whom the success of LBBP is anticipated to be challenging;
9. Severe renal dysfunction (eGFR < 15ml/min*1.73m^2).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: LBBP+GDMT group; Patients in the LBBP+GDMT group will receive LBBP using dual-chamber device as priority and guideline-directed medical therapy. The pacing lead will be implanted at the left bundle branch and whether LBB is captured will be judged during the procedure. For patients who LBBP is failed, CRTP using triple-chamber device or LVSP by using dual-chamber device will be an alternative option according to the co-determination after consultation between doctors and patients .	Device: LBBP+GDMT; LBBP is a procedure that the pacing lead is placed at the left bundle branch to achieve electrical and mechanical synchronization by pacing the left bundle branch area with stable pacing parameters.; Other Names: Early Resynchc
Active Comparator: GDMT group; Patients in the GDMT group will receive guideline-directed medical therapy according to their complications, heart rate, blood pressure and so on. During follow-up of 6 months, patients may transfer to LBBP group if the LVEF decreased to <35% and patients accepted the device implantation.	Drug: GDMT; GDMT is defined as the drug strategy for treatment of heart failure according to the current guidelines.; Other Names: Conventional treatment

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
ΔLVEF between baseline and 6-month follow-up	ΔLVEF：change in LVEF in percentage (%) between baseline and 6-month follow-up	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composite incidence rate of all-cause mortality and/or hospitalization for heart failure	All-cause death: including cardiovascular and non-cardiovascular deaths. Hospitalization for heart failure: an unplanned outpatient or emergency department visit or inpatient hospitalization in which the patient presented with signs and symptoms consistent with heart failure and required medication therapy.	6 months
ΔLVEDD and ΔLVESV between baseline and 6-month follow-up	ΔLVEDD：change in LVEDD in millimeters between baseline and 6-month follow-up between two groups. ΔLVESV：change in LVESV in milliliters between baseline and 6-month follow-up between two groups.	6 months
The echocardiographic response rate of LVEF ≥50%	the percentage of patients with LVEF ≥50% at 6 month follow-up	6 months
The changes of NYHA function class between baseline and 6-month follow-up.	NYHA function class (from I to IV) is evaluated by clinicians at each outpatient follow-up visit;	6 months
The rate of LVEF <=35% at six-month	The percentage of patients with LVEF <=35% at 6 month follow-up	6 months
The changes of NT-proBNP between baseline and 6-month follow-up.	NT-proBNP in pg/ml was measured by performing a blood test;	6 months
The changes of 6MWD between baseline and 6-month follow-up.	6MWD in meters stands for "6-Minute Walk Distance." It is a common test used to assess a person's functional exercise capacity and cardiovascular endurance. During the test, the patient is asked to walk as far as possible within a span of 6 minutes in a straight path or designated walking course;	6 months
The changes of QoL between baseline and 6-month follow-up.	QoL stands for "Quality of Life", which is measured by The Minnesota Living with Heart Failure Questionnaire (MLHFQ). The MLHFQ is a self-administered disease-specific questionnaire for patients with HF, comprising 21 items from 0 (none) to 5 (very much). It provides a total score (range 0-105, from best to worst HRQoL).	6 months

Collaborators and Investigators

• Sponsor: Fu Wai Hospital, Beijing, China
• Collaborators: The First Affiliated Hospital with Nanjing Medical University
• Investigators: Principal Investigator: Xiaohan Fan, PhD, Chinese Academy of Medical Sciences, Fuwai Hospital

Study record dates

Study Major Dates

• Study Start (Actual): June 26, 2023
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): June 1, 2026

Study Registration Dates

• First Submitted: September 5, 2023
• First Submitted That Met QC Criteria: November 8, 2023
• First Posted (Actual): November 13, 2023

Study Record Updates

• Last Update Posted (Actual): March 31, 2026
• Last Update Submitted That Met QC Criteria: March 30, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Heart Failure; Left Bundle Branch Pacing; Guideline-Directed Medical Therapy
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Heart Diseases; Heart Failure
• Other Study ID Numbers: 2023-1996

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No