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.

Trial Health

Monitor

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment

participants targeted

Target at below P25 for not_applicable heart-failure

Timeline

Completed

Started Jan 2011

Typical duration for not_applicable heart-failure

Geographic Reach

1 country

2 active sites

Status

terminated

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

3.6 years study duration

First Submitted

Initial submission to the registry

July 22, 2010

Completed

4 days until next milestone

First Posted

Study publicly available on registry

July 26, 2010

Completed

5 months until next milestone

Study Start

First participant enrolled

January 1, 2011

Completed

3.6 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

August 1, 2014

Completed

Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

August 1, 2014

Completed

1.2 years until next milestone

Results Posted

Study results publicly available

September 30, 2015

Completed

Last Updated

September 23, 2016

Status Verified

August 1, 2016

Enrollment Period

3.6 years

First QC Date

July 22, 2010

Results QC Date

August 28, 2015

Last Update Submit

August 1, 2016

Conditions

Heart Failure Right Bundle-Branch Block

Keywords

Heart FailureRight Bundle-Branch BlockCardiac Resynchronization Therapy

Outcome Measures

Primary Outcomes (1)

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

Secondary Outcomes (7)

Secondary Echocardiographic Endpoints
6 months
Arrhythmic Events
6 months
Minnesota Quality of Life Questionnaire
6 months
6-minute Walk Distance
6 months
NYHA Function Class
6 months
+2 more secondary outcomes

Study Arms (6)

VVI-40 to RV DDD-40 to Bi-V DDD-40

EXPERIMENTAL

Period 1: Participants assigned to VVI-40 Participants will then Crossover to Period 2. Period 2: Participants assigned to RV DDD-40 Participants will then Crossover to Period 3. Period 3: Participants assigned to Bi-V DDD-40