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

Study Status: Terminated
Recruit Status: Terminated
Study Type: Interventional

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

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 qual

Detailed Summary:
Sponsor: Duke University

Current Primary Outcome: 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. [ Time Frame: 6 months ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

• Secondary Echocardiographic Endpoints [ Time Frame: 6 months ]
  Comparisons of the derived velocity-time integral calculated on the aortic continuous wave Doppler-spectrogram, RV end-diastolic size, RV EF, mitral and tricuspid regurgitation severity, and estimated RV systolic pressure.
• Arrhythmic Events [ Time Frame: 6 months ]
  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.
• Minnesota Quality of Life Questionnaire [ Time Frame: 6 months ]
  This is a standardized method for assessing quality of life in patients with heart failure. It asks 21 questions and measures the impact HF has on a subject's life. Each question is rated 0-5. The total score for the 21 items can range from 0 to 105. Higher scores indicate more burden of disease on quality of life.
• 6-minute Walk Distance [ Time Frame: 6 months ]
  6-minute walk distance was the distance that a participant could walk in 6 minutes.
• NYHA Function Class [ Time Frame: 6 months ]
  The New York Heart Association (NYHA) Functional Classification places patients in one of four categories based on how much they are limited during physical activity. Class I means there is no limitation of physical activity and Class IV means a person is unable to carry on any physical activity without discomfort/symptoms of heart failure at rest.
• Left Ventricular Ejection Fraction (LVEF) [ Time Frame: 6 months ]
• Left Ventricular End-diastolic Size [ Time Frame: 6 months ]

Original Secondary Outcome:

• Secondary Echocardiographic Endpoints [ Time Frame: 6 months ]
  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.
• 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. [ Time Frame: 6 months ]
• Arrhythmic Events [ Time Frame: 6 months ]
  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.

Dates:
Date Received: July 22, 2010
Date Started: January 2011
Date Completion:
Last Updated: August 1, 2016
Last Verified: August 2016