Conduction System Pacing vs Biventricular Pacing in Systolic Dysfunction and Wide QRS: Mortality, Heart Failure Hospitalization or Cardiac Transplant (CONSYST-CRT II)

Hospital Clinic of Barcelona

Status: Enrolling

Conditions: Heart Failure; Cardiac Resynchronization Therapy

Treatments: Procedure: Biventricular pacing; Procedure: Conduction system pacing

Study type: Interventional

Funder types: Other

Identifiers

NCT06105580

CONSYST-CRT II

Details and patient eligibility

About

Conduction system pacing vs biventricular resynchronization therapy in systolic dysfunction and wide QRS: mortality, heart failure hospitalization or cardiac transplant (CONSYST-CRT II trial).

Superiority trial that aims to study the composite endpoint consisting of all-cause mortality, cardiac transplant or heart failure hospitalization at 12-month follow-up.

Full description

To date, studies have shown that conduction system pacing could get similar clinical and echocardiographic responses to those obtained with biventricular therapy.

This study will randomize 320 patients to a strategy of biventricular pacing versus conduction system pacing.

CONSYST-CRT II study will analyze a clinical endpoint as primary endpoint and the following parameters in both groups: left ventricular ejection fraction, ventricular volumes, echocardiographic response (>=15% decrease in left ventricular end-systolic volume), NYHA functional class, heart failure hospitalization, all-cause mortality, cardiac transplant, QRS shortening, echocardiographic dyssynchrony (atrioventricular, interventricular, intraventricular) and global longitudinal strain.

As a secondary endpoint, baseline predictors of response to conduction system pacing and biventricular pacing according to cardiac magnetic ressonance and electrocardiographic imaging will be studied.

Clinical, electrocardiographic, echocardiographic follow-up will be performed during 12 months.

Enrollment: 320 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patient must indicate acceptance to participate in the study by signing an informed consent document.
• Patient must be ≥ 18 years of age.
• Left bundle branch block, QRS ≥130 and LVEF <=35%. No indication of stimulation for AV block.
• Non-left bundle branch block, QRS ≥150 and LVEF <=35%.
• Resynchronization therapy indication for ventricular dysfunction (LVEF <40%) and indication of cardiac pacing for AV block.
• LVEF <=35% in NYHA class III or IV, atrial fibrillation and intrinsic QRS >=130 ms, provided a strategy to ensure biventricular capture is in place.

Exclusion criteria

• Myocardial infarction, unstable angina or cardiac revascularization during the previous 3 months.
• Pregnancy.
• Participating currently in a clinical investigation that includes an active treatment.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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320 participants in 2 patient groups

Conduction system pacing

Experimental group

Description:

Pacing the His-Purkinje system. Crossover to biventricular pacing allowed in case of failed conduction system pacing: failed His bundle pacing and failed Left bundle branch pacing (high thresholds (\>3.5V / 1ms); no left bundle branch pacing criteria; no left bundle branch correction). Electrocardiographic optimization allowed in order to obtain the narrowest QRS.

Treatment:

Procedure: Conduction system pacing

Biventricular pacing

Active Comparator group

Description:

Pacing from the right ventricular and coronary sinus lead. Electrocardiographic optimization with fusion-optimized intervals (FOI). Crossover from biventricular pacing to conduction system pacing will be allowed in the following situations: coronary sinus cannot be cannulated; no lateral or posterolateral branches; or phrenic stimulation.

Treatment:

Procedure: Biventricular pacing