Pacing Affects Cardiovascular Endpoints in Patients With Right Bundle-Branch Block (The PACE-RBBB Trial)

Heart Failure Clinical Trial

— PACE-RBBB  

Official title:

Pacing Affects Cardiovascular Endpoints in Patients With Right Bundle-Branch Block (The PACE-RBBB Trial)

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01169493
• Other study ID #: Pro00025144
• Secondary ID: 10CRP3630033
• Status: Completed
• Phase: N/A
• First received: July 22, 2010
• Last updated: August 28, 2015
• Start date: January 2011
• Est. completion date: August 2014

Study information

• Verified date: August 2015
• Source: Duke University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 16
• Est. completion date: August 2014
• Est. primary completion date: August 2014
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

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

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Investigator, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Bundle-Branch Block
• Heart Block
• Heart Failure
• Right Bundle-Branch Block

Intervention

Device:
• VVI-40
Pacing mode set to VVI-40, RV only pacing
• RV DDD-40
ICD programmed to DDD-40, RV only pacing with aan AV interval producing QRS fusion on surface EKG.
• BiV DDD-40
ICD programmed to BiV pacing at a lower rate of 40

Locations

Country	Name	City	State
United States	Duke University Medical Center	Durham	North Carolina
United States	Durham VA Medical Center	Durham	North Carolina

Sponsors (2)

Lead Sponsor	Collaborator
Duke University	American Heart Association

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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.		6 months	No
Secondary	Secondary Echocardiographic Endpoints	Comparisons of the derived velocity-time integral calculated on the aortic continuous wave Doppler-spectrogram, comparisons of LV and RV end-diastolic size, LV and RV EF, mitral and tricuspid regurgitation severity, and estimated RV systolic pressure.	6 months	Yes
Secondary	Secondary Endpoints of the PACE-RBBB Trial Will Also Include Comparisons of NYHA Functional Class, 6-minute Walk Distance, and Minnesota Quality of Life Questionnaire Scores Between Treatment Groups.		6 months	Yes
Secondary	Arrhythmic Events	To determine if pacing mode impacts the frequency of ventricular arrhythmias, the incidence of ventricular tachyarrhythmia episodes on device interrogation will be compared between treatment group assignments. An episode will be considered ventricular arrhythmia if it lasts longer than 30 seconds or requires anti-tachycardia pacing or high voltage device therapy for termination.	6 months	Yes