Sildenafil Therapy for Pulmonary Hypertension and Sickle Cell Disease

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00492531
Recruitment Status : Terminated (Subjects on drug were more likely to have severe pain crises requiring hospitalization.)
First Posted : June 27, 2007
Results First Posted : June 6, 2011
Last Update Posted : January 6, 2016
Information provided by (Responsible Party):
Mark Gladwin, National Heart, Lung, and Blood Institute (NHLBI)

Study Type: Interventional
Study Design: Allocation: Randomized;   Intervention Model: Parallel Assignment;   Masking: Double (Participant, Investigator);   Primary Purpose: Treatment
Conditions: Sickle Cell Disease
Pulmonary Hypertension
Interventions: Drug: Sildenafil
Drug: Placebo

  Participant Flow

  Baseline Characteristics

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
Sildenafil Subjects received oral sildenafil 20 mg three times daily for six weeks, followed by 40 mg three times daily for four weeks, followed by 80 mg three times daily for six weeks (as tolerated).
Placebo Subjects received matching oral dose of placebo 20 mg three times daily for six weeks, followed by 40 mg three times daily for four weeks, followed by 80 mg three times daily for six weeks (as tolerated).
Total Total of all reporting groups

Baseline Measures
   Sildenafil   Placebo   Total 
Overall Participants Analyzed 
[Units: Participants]
 37   37   74 
[Units: Years]
Mean (Standard Deviation)
 47  (13)   44  (14)   45  (13) 
[Units: Participants]
Female   23   23   46 
Male   14   14   28 
Ethnicity (NIH/OMB) 
[Units: Participants]
Hispanic or Latino   0   0   0 
Not Hispanic or Latino   32   37   69 
Unknown or Not Reported   5   0   5 
Race (NIH/OMB) 
[Units: Participants]
American Indian or Alaska Native   0   0   0 
Asian   0   0   0 
Native Hawaiian or Other Pacific Islander   0   0   0 
Black or African American   36   37   73 
White   0   0   0 
More than one race   0   0   0 
Unknown or Not Reported   1   0   1 
6 minute walk [1] 
[Units: Meters]
Mean (Standard Deviation)
 381  (75)   386  (75)   383  (75) 
[1] The distance walked in six minute was used to assess the exercise capacity of the patient at baseline.
Tricuspid regurgitant jet velocity (TRV) [1] 
[Units: M/s]
Mean (Standard Deviation)
 3.0  (0.5)   3.0  (0.3)   3.0  (0.3) 
[1] Tricuspid regurgitant jet velocity was measured by transthoracic Doppler Echocardiography.

  Outcome Measures

1.  Primary:   Change in Exercise Capacity as Assessed by 6 Minute Walk.   [ Time Frame: Baseline to week 16/Imputed last visit. ]

2.  Secondary:   Change From Baseline in Pulmonary Hypertension at Week 16 as Assessed by Tricuspid Regurgitant Jet Velocity   [ Time Frame: 16 weeks ]

3.  Secondary:   Borg Dyspnea Score   [ Time Frame: baseline to 16 weeks ]

4.  Secondary:   Brain Natriuretic Peptide(BNP)Levels.   [ Time Frame: 16 weeks ]

  Serious Adverse Events

  Other Adverse Events

  Limitations and Caveats

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
As a result of early termination due to safety findings, the study was underpowered to assess the effects of sildenafil therapy on the predetermined efficacy endpoints.

  More Information

Certain Agreements:  
Principal Investigators are NOT employed by the organization sponsoring the study.
There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.

Results Point of Contact:  
Name/Title: Mark Gladwin
Organization: Professor of Medicine: Chief, Pulmonary, Allergy and Critical Care Medicine: Director, Hemostasis and Vascular Biology Research Institute; University of Pittsburgh School of Medicine
phone: 412-692-2117

Publications automatically indexed to this study by Identifier (NCT Number):

Responsible Party: Mark Gladwin, National Heart, Lung, and Blood Institute (NHLBI) Identifier: NCT00492531     History of Changes
Other Study ID Numbers: 070177
07-H-0177 ( Other Identifier: IRB Approval number , NHLBI )
First Submitted: June 26, 2007
First Posted: June 27, 2007
Results First Submitted: April 28, 2011
Results First Posted: June 6, 2011
Last Update Posted: January 6, 2016