Clinical trial NCT01169493: Pacing Affects Cardiovascular Endpoints in Patients With Right Bundle-Branch Block (The PACE-RBBB Trial)
Official title: Pacing Affects Cardiovascular Endpoints in Patients With Right Bundle-Branch Block (The PACE-RBBB Trial)
Study type: INTERVENTIONAL
Overall status: TERMINATED
Phase: NA
Conditions: Heart Failure
Right Bundle-Branch Block
Keywords: Heart Failure
Right Bundle-Branch Block
Cardiac Resynchronization Therapy
Lead sponsor: Duke University
Sponsor class: OTHER
Collaborators: name: American Heart Association
First posted: 2010-07-26
Enrollment: 16
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: Heart failure (HF) affects 5 million Americans and is responsible for more health-care expenditure than any other medical diagnosis. Approximately half of all HF patients have electrocardiographic prolongation of the QRS interval and ventricular dyssynchrony, a perturbation of the normal pattern of ventricular contraction that reduces the efficiency of ventricular work. Ventricular dyssynchrony is directly responsible for worsening HF symptomatology in this subset of patients. Resynchronization of ventricular contraction is usually achieved through simultaneous pacing of the left and right ventricles using a biventricular (BiV) pacemaker or implantable cardioverter-defibrillator. Clinical trial evidence supporting the use of BiV pacing in patients with prolonged QRS duration was obtained almost exclusively in patients with a left bundle-branch block (LBBB) electrocardiographic pattern. Recent evidence suggests that resynchronization of ventricular contraction in patients with LBBB can be obtained by univentricular left ventricular pacing with equal or superior clinical benefits compared to BiV pacing. Animal studies suggest that ventricular resynchronization can be obtained in subjects with right bundle-branch block (RBBB) through univentricular right ventricular pacing. No clinical trial evidence exists to support the use of BiV pacing in patients with RBBB. Thousands of patients with symptomatic HF and RBBB currently have univentricular ICDs in place for the prevention of sudden cardiac death. Most of these devices are currently programmed to avoid RV pacing. We aim to determine if ventricular resynchronization delivered through univentricular RV pacing improves symptoms in patients with RBBB and moderate to severe HF who have previously undergone BiV ICD implantation for symptomatic heart failure. We further aim to determine if ventricular resynchronization improves myocardial performance and ventricular geometry as detected by echocardiographic measures and quality of life for patients with HF and RBBB. We hypothesize that RV univentricular pacing delivered with an atrio-ventricular interval that maximizes ventricular synchrony is equivalent to BiV pacing for improvement in cardiac performance, HF symptoms, and positive ventricular remodeling in patients with HF and RBBB.


Eligibility criteria: Inclusion Criteria:

* Cardiomyopathy of either idiopathic or ischemic etiology
* NYHA class III, or IV symptoms
* Sinus rhythm
* QRS complex duration \> 130 msec in ≥ 2 surface ECG leads with RBBB
* PR interval \> 150 msec and \< 240 msec
* Prior implantation of dual chamber BiV ICD with apical RV lead location

Exclusion Criteria:

* Myocardial infarction, major surgical procedure, or acute cardiac failure crisis requiring inotropes within 6 months of entry into the study
* Atrial fibrillation or flutter lasting \>12 hours within the last 6 months
* Sick sinus syndrome, complete heart block, or other arrhythmias requiring pacemaker support
* Pregnancy
* Any other known condition other than heart failure that could limit exercise time or survival to \< 6 months

Primary outcomes:
measure: The Primary Endpoint of the Trial Will be a Comparison of the Proportion of Patients in Each of the Three Treatment Groups Who Demonstrate Positive LV Remodeling, Defined as a Decrease in LV End Systolic Diameter of >5mm.
timeFrame: 6 months
Secondary outcomes:
measure: Secondary Echocardiographic Endpoints
timeFrame: 6 months
measure: Arrhythmic Events
timeFrame: 6 months
measure: Minnesota Quality of Life Questionnaire
timeFrame: 6 months
measure: 6-minute Walk Distance
timeFrame: 6 months
measure: NYHA Function Class
timeFrame: 6 months
measure: Left Ventricular Ejection Fraction (LVEF)
timeFrame: 6 months
measure: Left Ventricular End-diastolic Size
timeFrame: 6 months
Other outcomes:
Locations:
city: Durham
country: United States
facility: Duke University Medical Center
state: North Carolina
city: Durham
country: United States
facility: Durham VA Medical Center
state: North Carolina
Study officials:
affiliation: Duke University
name: Brett D Atwater, MD
role: PRINCIPAL_INVESTIGATOR
References: