NCT Number: NCT07560891
This is a prospective, multicenter, randomized controlled trial comparing Left Bundle Branch Area Pacing (LBBAP)-based cardiac resynchronization therapy (CRT) with conventional coronary sinus (CS) lead-based CRT in patients with permanent atrial fibrillation (AF) and heart failure (HF) who meet indications for CRT device implantation.
Atrial fibrillation and heart failure frequently coexist, and both rapid heart rate and its irregularity contribute to worsening cardiac function. Atrioventricular junction (AVJ) ablation combined with CRT (biventricular pacing) has been established as an effective strategy for rate control and cardiac resynchronization in this population, supported by Class I recommendation in the 2021 ESC guidelines. However, conventional biventricular CRT via the CS lead can induce artificial electrical dyssynchrony, particularly in patients with a narrow QRS complex, potentially limiting its benefit.
Conduction system pacing (CSP), including LBBAP, has emerged as a physiologic alternative that directly stimulates the native conduction system, preserving synchronous ventricular activation. Recent evidence (ALTERNATIVE-AF trial) suggests CSP may be superior to biventricular CRT in permanent AF patients undergoing AVJ ablation. However, no randomized controlled trial has directly compared LBBAP-based CRT with CS lead-based CRT in this specific population.
The SYNC-AF trial will randomize 44 patients (22 per arm) to either LBBAP or CS pacing for CRT. The primary endpoint is change in left ventricular ejection fraction (LVEF) at 12 months as assessed by echocardiography in a blinded core laboratory. Secondary endpoints include changes in QRS duration, major adverse clinical events, device/procedure-related complications, and ventricular arrhythmia burden.
Trial opening soon.
Get Notified19 year and older
All sexes
Interventional
Not applicable
ECHOCARDIOGRAPHIC CORE LAB:
All echocardiographic assessments (LVEF, LVESV, LVEDV, etc.) are performed and interpreted by a blinded independent core laboratory at Severance Hospital to ensure objective and consistent measurement.
FOLLOW-UP SCHEDULE:
Screening (implant day) → Visit 1 (2 weeks-1 month) → Visit 2 (3 months ±3 months) → Visit 3 (6 months ±3 months) → Visit 4 (12 months ±3 months).
STATISTICAL ANALYSIS:
Primary analysis follows the Intention-To-Treat (ITT) principle. Per-Protocol (PP) analysis will be performed as sensitivity analysis. The primary endpoint (LVEF change at 12 months) will be compared using Student's t-test or Wilcoxon rank-sum test. Time-to-event analyses will use Kaplan-Meier survival curves with log-rank test and Cox proportional hazards model.
SAMPLE SIZE:
44 patients total (22 per arm). Based on the assumption of an absolute 10% greater improvement in LVEF with LBBAP-CRT vs. BiV-CRT, with 80% power and 5% two-sided alpha, with 10% dropout allowance.
PARTICIPATING CENTERS:
Multiple centers in the Republic of Korea (at least 4 centers), led by Severance Hospital, Yonsei University College of Medicine.
Healthy volunteers accepted: No
Only the study team can determine whether someone qualifies for participation.
Inclusion criteria
Exclusion criteria
CRT device (CRT-P or CRT-D) implantation using LBBAP as the left ventricular pacing lead. A pacing lead is advanced through the interventricular septum to achieve left bundle branch area capture, confirmed by pacing parameters and electrocardiographic criteria (RBBB-like pattern with short R-peak latency in V5/V6). RV lead is implanted in standard fashion. AVJ ablation may be performed per clinical indication.
CRT device (CRT-P or CRT-D) implantation using a conventional coronary sinus (CS) lead as the left ventricular pacing lead. The CS lead is advanced via the coronary sinus into a lateral or posterolateral cardiac vein to achieve biventricular pacing. RV lead is implanted in standard fashion. AVJ ablation may be performed per clinical indication.
Time frame: Baseline (at the time of device implantation) and 12 months post-implantation
Change in left ventricular ejection fraction (LVEF) from baseline to 12 months post-implantation, as measured by transthoracic echocardiography performed and interpreted by a blinded independent central core laboratory. LVEF is assessed using the biplane Simpson method.
Time frame: 12 months post-implantation
Echocardiographic CRT response defined as absolute improvement in LVEF of ≥5% or ≥10% from baseline at 12 months, assessed by blinded core lab.
Time frame: 12 months post-implantation
Echocardiographic CRT response defined as absolute improvement in LVEF of ≥5% or ≥10% from baseline at 12 months, assessed by blinded core lab.
Time frame: Immediately post-implant and at 12 months
QRS duration measured from surface ECG in milliseconds.
Time frame: Up to 12 months
Time from randomization to first detection of treated ventricular arrhythmia (VT/VF) recorded by the implanted device within 12 months.
Time frame: Up to 12 months (first occurrence)
Clinical events adjudicated by an independent committee. Heart failure hospitalization defined as unplanned outpatient/ED visit or inpatient admission with HF signs/symptoms requiring intravenous therapy.
Time frame: Up to 12 months (first occurrence)
Clinical events adjudicated by an independent committee. Heart failure hospitalization defined as unplanned outpatient/ED visit or inpatient admission with HF signs/symptoms requiring intravenous therapy.
Time frame: Up to 12 months (first occurrence)
Clinical events adjudicated by an independent committee. Heart failure hospitalization defined as unplanned outpatient/ED visit or inpatient admission with HF signs/symptoms requiring intravenous therapy.
Time frame: Up to 12 months (first occurrence)
Clinical events adjudicated by an independent committee. Heart failure hospitalization defined as unplanned outpatient/ED visit or inpatient admission with HF signs/symptoms requiring intravenous therapy.
Time frame: Immediately after the implantation procedure
Successful LBBAP lead placement defined by achievement of left bundle branch capture with acceptable pacing threshold (≤1.5V/0.5ms), impedance (300-1200Ω), and electrocardiographic criteria (RBBB pattern, short R-peak latency in V5/V6).
Time frame: 12 months post-implantation
Loss of left bundle branch capture or inability to maintain pacing threshold <2.5V/0.5ms at 12 months.
Time frame: Up to 12 months
Composite endpoint defined as ≥5% absolute decrease in LVEF from baseline or ≥15% increase in LVESV from baseline during follow-up.
Time frame: Up to 12 months (device/procedure-related complications within 7 days for acute; up to 12 months for chronic)
All device/procedure-related complications and reinterventions occurring up to 12 months, adjudicated by an independent events committee.
Time frame: Up to 12 months
All device/procedure-related complications and reinterventions occurring up to 12 months, adjudicated by an independent events committee.
Contact information is provided by the study sponsor or research team.
Yonsei University
Other
Left Bundle Branch Area Pacing Versus Coronary Sinus Pacing for Cardiac Resynchronization Therapy for Patients With Permanent Atrial Fibrillation and Heart Failure: The SYNC-AF Trial
Acronym: SYNC-AF
OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.
View the official ClinicalTrials.gov record (opens in a new tab)This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.
Published trials that share one or more normalized conditions with this study.
NCT07339007
Arrhythmias, Cardiac, Arterial Hypertension
Barcelona, Catalonia, Spain
View Trial DetailsNCT06763549
Apnea, Apnea, Obstructive
Melbourne, Florida, United States
View Trial DetailsNCT07604727
Arrhythmias, Cardiac, Atrial Fibrillation
Grenoble, France
View Trial DetailsNCT07567378
Arrhythmias, Cardiac, Arterial Occlusive Diseases
Mexico City, Mexico
View Trial Details