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Evaluating the Effectiveness of Sildenafil at Improving Health Outcomes and Exercise Ability in People With Diastolic Heart Failure (The RELAX Study) (RELAX)

This study has been completed.
Sponsor:
Collaborators:
National Heart, Lung, and Blood Institute (NHLBI)
Pfizer
Information provided by (Responsible Party):
Duke University
ClinicalTrials.gov Identifier:
NCT00763867
First received: September 30, 2008
Last updated: July 14, 2014
Last verified: July 2013
Results First Received: April 4, 2013  
Study Type: Interventional
Study Design: Allocation: Randomized;   Intervention Model: Parallel Assignment;   Masking: Double Blind (Subject, Caregiver, Investigator);   Primary Purpose: Treatment
Condition: Heart Failure
Interventions: Drug: Placebo
Drug: Sildenafil

  Participant Flow
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Recruitment Details
Key information relevant to the recruitment process for the overall study, such as dates of the recruitment period and locations
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Pre-Assignment Details
Significant events and approaches for the overall study following participant enrollment, but prior to group assignment
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Reporting Groups
  Description
Placebo placebo 20 mg three tid for 12 weeks followed by 60 mg tid for 12 weeks
Sildenafil sildenafil 20 mg three tid for 12 weeks followed by 60 mg tid for 12 weeks

Participant Flow:   Overall Study
    Placebo   Sildenafil
STARTED   103   113 
COMPLETED   98   101 
NOT COMPLETED   5   12 



  Baseline Characteristics
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Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate.
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Reporting Groups
  Description
Placebo 20 mg tid for 12 weeks followed by 60 mg tid for 12 weeks
Sildenafil 20 mg tid for 12 weeks followed by 60 mg tid for 12 weeks
Total Total of all reporting groups

Baseline Measures
   Placebo   Sildenafil   Total 
Overall Participants Analyzed 
[Units: Participants]
 103   113   216 
Age 
[Units: Participants]
     
<=18 years   0   0   0 
Between 18 and 65 years   42   38   80 
>=65 years   61   75   136 
Age 
[Units: Years]
Mean (Standard Deviation)
 68.7  (10.1)   68.4  (10.5)   68.5  (10.3) 
Gender 
[Units: Participants]
     
Female   55   49   104 
Male   48   64   112 
Region of Enrollment 
[Units: Participants]
     
United States   93   101   194 
Canada   10   12   22 


  Outcome Measures
  Show All Outcome Measures

1.  Primary:   Exercise Capacity, as Determined by Peak Oxygen Uptake   [ Time Frame: Change from Baseline to Week 24 ]

2.  Secondary:   Exercise Capacity, as Determined by Peak Oxygen Uptake   [ Time Frame: Change from Baseline to Week 12 ]

3.  Secondary:   Exercise Capacity as Determined by Walk Distance   [ Time Frame: Change from Baseline to Week 12 ]

4.  Secondary:   Composite Score Reflective of Clinical Status   [ Time Frame: Measured at Week 24 ]

5.  Secondary:   Exercise Capacity as Determined by Walk Distance   [ Time Frame: Change from Baseline to Week 24 ]

6.  Secondary:   Cardiopulmonary Exercise Test (CPET) Duration   [ Time Frame: Change from Baseline to Week 12 ]

7.  Secondary:   Cardiopulmonary Exercise Test (CPET) Duration   [ Time Frame: Change from Baseline to Week 24 ]

8.  Secondary:   Ventilatory Anaerobic Threshold   [ Time Frame: Change from Baseline to Week 12 ]
  Hide Outcome Measure 8

Measure Type Secondary
Measure Title Ventilatory Anaerobic Threshold
Measure Description To interpret the Ventilatory Anaerobic Threshold (VAT) change endpoints, an increase in VAT between Baseline and Week 12/Week 24 is considered to be an improvement
Time Frame Change from Baseline to Week 12  
Safety Issue No  

Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate.
Participants analyzed consisted of those participants who had the endpoint data available to be derived.

Reporting Groups
  Description
Placebo placebo 20 mg three tid for 12 weeks followed by 60 mg tid for 12 weeks
Sildenafil sildenafil 20 mg three tid for 12 weeks followed by 60 mg tid for 12 weeks

Measured Values
   Placebo   Sildenafil 
Participants Analyzed 
[Units: Participants]
 96   92 
Ventilatory Anaerobic Threshold 
[Units: Ml/min/kg]
Mean (Standard Deviation)
 -0.01  (1.14)   0.06  (1.24) 

No statistical analysis provided for Ventilatory Anaerobic Threshold



9.  Secondary:   Ventilatory Anaerobic Threshold   [ Time Frame: Change from Baseline to Week 24 ]

10.  Secondary:   Minnesota Living With Heart Failure Questionnaire (MLWHFQ)   [ Time Frame: Change from Baseline to Week 12 ]

11.  Secondary:   Minnesota Living With Heart Failure Questionnaire   [ Time Frame: Change from Baseline to Week 24 ]

12.  Other Pre-specified:   MRI Left Ventricular Mass   [ Time Frame: Change from Baseline to Week 24 ]

13.  Other Pre-specified:   MRI Left Ventricular Mass Index   [ Time Frame: Change from Baseline to Week 24 ]

14.  Other Pre-specified:   MRI Left Ventricular End Diastolic Volume   [ Time Frame: Change from Baseline to Week 24 ]

15.  Other Pre-specified:   MRI Left Ventricular End Diastolic Volume Index   [ Time Frame: Change from Baseline to Week 24 ]

16.  Other Pre-specified:   MRI Left Ventricular End Systolic Volume Index   [ Time Frame: Change from Baseline to Week 24 ]

17.  Other Pre-specified:   MRI Left Ventricular Ejection Fraction (LVEF)   [ Time Frame: Change from Baseline to Week 24 ]

18.  Other Pre-specified:   Echocardiogram Left Ventricular Mass   [ Time Frame: Change from Baseline to Week 24 ]

19.  Other Pre-specified:   Medial Diastolic Elastance   [ Time Frame: Change from Baseline to Week 24 ]

20.  Other Pre-specified:   Lateral Diastolic Elastance   [ Time Frame: Change from Baseline to Week 24 ]

21.  Other Pre-specified:   Medial Left Ventricular Relaxation   [ Time Frame: Change from Baseline to Week 24 ]

22.  Other Pre-specified:   Lateral Left Ventricular Relaxation   [ Time Frame: Change from Baseline to Week 24 ]

23.  Other Pre-specified:   Medial Filling Pressure   [ Time Frame: Change from Baseline to Week 24 ]

24.  Other Pre-specified:   Lateral Filling Pressure   [ Time Frame: Change from Baseline to Week 24 ]

25.  Other Pre-specified:   ECHO Effective Arterial Elastance   [ Time Frame: Change from Baseline to Week 24 ]

26.  Other Pre-specified:   ECHO Systemic Vascular Resistance   [ Time Frame: Change from Baseline to Week 24 ]

27.  Other Pre-specified:   MRI Effective Arterial Elastance   [ Time Frame: Change from Baseline to Week 24 ]

28.  Other Pre-specified:   MRI Systemic Vascular Resistance   [ Time Frame: Change from Baseline to Week 24 ]

29.  Other Pre-specified:   MRI Aortic Thickness   [ Time Frame: Change from Baseline to Week 24 ]

30.  Other Pre-specified:   MRI Aortic Distensibility   [ Time Frame: Change from Baseline to Week 24 ]

31.  Other Pre-specified:   ECHO Pulmonary Artery Systolic Pressure   [ Time Frame: Change from Baseline to Week 24 ]

32.  Other Pre-specified:   Best Available Creatinine   [ Time Frame: Change from Baseline to Week 24 ]

33.  Other Pre-specified:   Best Available Glomerular Filtration Rate (GFR)   [ Time Frame: Change from Baseline to Week 24 ]

34.  Other Pre-specified:   Cystatin C   [ Time Frame: Change from Baseline to Week 24 ]

35.  Other Pre-specified:   Uric Acid   [ Time Frame: Change from Baseline to Week 24 ]

36.  Other Pre-specified:   N-terminal Pro B-type Natriuretic Peptide (NT Pro-BNP)   [ Time Frame: Change from Baseline to Week 24 ]

37.  Other Pre-specified:   Aldosterone   [ Time Frame: Change from Baseline to Week 24 ]

38.  Other Pre-specified:   High Sensitivity Troponin I   [ Time Frame: Change from Baseline to Week 24 ]

39.  Other Pre-specified:   Procollagen III N-terminal Peptide   [ Time Frame: Change from Baseline to Week 24 ]

40.  Other Pre-specified:   Endothelin-1   [ Time Frame: Change from Baseline to Week 24 ]

41.  Other Pre-specified:   High Sensitivity C-Reactive Protein   [ Time Frame: Change from Baseline to Week 24 ]

42.  Other Pre-specified:   Collagen Type I (CITP)   [ Time Frame: Change from Baseline to Week 24 ]

43.  Other Pre-specified:   Cyclic Guanosine Monophosphate (cGMP)   [ Time Frame: Change from Baseline to Week 24 ]

44.  Other Pre-specified:   Galectin 3   [ Time Frame: Change from Baseline to Week 24 ]

45.  Other Pre-specified:   Furosemide-Equivalent Dose   [ Time Frame: Change from Baseline to Week 24 ]


  Serious Adverse Events


  Other Adverse Events


  Limitations and Caveats
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Limitations of the study, such as early termination leading to small numbers of participants analyzed and technical problems with measurement leading to unreliable or uninterpretable data
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  More Information