Trial · NCT00492531

Sildenafil Therapy for Pulmonary Hypertension and Sickle Cell Disease

NCT00492531, Phase 2, Terminated, National Heart, Lung, and Blood Institute (NHLBI); results first posted 2011-06-06

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. Sildenafil Therapy for Pulmonary Hypertension and Sickle Cell Disease. Trials, record NCT00492531. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT00492531

On this page

Trial

As registered on ClinicalTrials.gov, in the graph's capture of the registry.

Title: Sildenafil Therapy for Pulmonary Hypertension and Sickle Cell Disease
NCT number: NCT00492531
Status: Terminated
Phases: Phase 2
Enrollment: 74 participants, actual
Lead sponsor: National Heart, Lung, and Blood Institute (NHLBI)
Conditions: Sickle Cell Disease, Pulmonary Hypertension
Interventions: Sildenafil, Placebo
First posted: 2007-06-27
Last updated: 2016-01-06
Results first posted: 2011-06-06
Limitations and caveats: 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.

Source ClinicalTrials.gov

Registered outcomes4

Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.

List	Outcome	Time frame	Description
Primary	Change in Exercise Capacity as Assessed by 6 Minute Walk.	Baseline to week 16/Imputed last visit.	The primary outcome measure was change in exercise capacity assessed by 6 minute walk distance in meters from baseline to 16 weeks. Subjects without a week 16 assessment had their last observation carried forward.
Secondary	Change From Baseline in Pulmonary Hypertension at Week 16 as Assessed by Tricuspid Regurgitant Jet Velocity	16 weeks	Secondary outcome measure was change from baseline in Pulmonary hypertension at week 16 as assessed by Tricuspid regurgitant jet velocity(TRV). Tricuspid regurgitant jet velocity was measured by transthoracic Doppler Echocardiography.
Secondary	Borg Dyspnea Score	baseline to 16 weeks	Borg dyspnea score was used to measure the level of severity of breathlessness perceived by the patient before and after 6 minute walk. The severity is measured on a 10 point scale with 0= nothing at all and 10=maximum severity of breathlessness.
Secondary	Brain Natriuretic Peptide(BNP)Levels.	16 weeks

Source ClinicalTrials.gov

Outcomes4

Each outcome the trial posted results for, in ClinicalTrials.gov's words.

Type	Outcome	Time frame	Population	Units	Measured as
SECONDARY	Change From Baseline in Pulmonary Hypertension at Week 16 as Assessed by Tricuspid Regurgitant Jet Velocity	16 weeks		meters/second	MEAN
SECONDARY	Borg Dyspnea Score	baseline to 16 weeks		Score on a scale	MEAN
SECONDARY	Brain Natriuretic Peptide(BNP)Levels.	16 weeks		pg/dl	MEAN
PRIMARY	Change in Exercise Capacity as Assessed by 6 Minute Walk.	Baseline to week 16/Imputed last visit.	All efficacy and safety analyses were conducted on the intent-to-treat (ITT) population, defined as all randomized subjects, regardless of therapy received. Pre-defined imputation rules:A value of 0 meters was imputed for subjects who died during the MIT.Subjects without a week 16 assessment had their last observation carried forward (LOCF).	meters	MEAN

Source ClinicalTrials.gov

Results by group24

Each measurement the trial posted, group by group, in the words and numbers it posted.

Outcome	Group	Category	Value	Spread	Units
Change From Baseline in Pulmonary Hypertension at Week 16 as Assessed by Tricuspid Regurgitant Jet Velocity	Sildenafil	Baseline	3.1	Standard Deviation 0.5	meters/second
Change From Baseline in Pulmonary Hypertension at Week 16 as Assessed by Tricuspid Regurgitant Jet Velocity	Placebo	Baseline	3.0	Standard Deviation 0.3	meters/second
Change From Baseline in Pulmonary Hypertension at Week 16 as Assessed by Tricuspid Regurgitant Jet Velocity	Sildenafil	Week 6	3.2	Standard Deviation 0.7	meters/second
Change From Baseline in Pulmonary Hypertension at Week 16 as Assessed by Tricuspid Regurgitant Jet Velocity	Placebo	Week 6	2.9	Standard Deviation 0.3	meters/second
Change From Baseline in Pulmonary Hypertension at Week 16 as Assessed by Tricuspid Regurgitant Jet Velocity	Sildenafil	Week 16	2.9	Standard Deviation 0.5	meters/second
Change From Baseline in Pulmonary Hypertension at Week 16 as Assessed by Tricuspid Regurgitant Jet Velocity	Placebo	Week 16	2.9	Standard Deviation 0.3	meters/second
Borg Dyspnea Score	Sildenafil	Baseline	2.5	Standard Deviation 2.1	Score on a scale
Borg Dyspnea Score	Placebo	Baseline	2.1	Standard Deviation 2.0	Score on a scale
Borg Dyspnea Score	Sildenafil	Week 6	3.4	Standard Deviation 2.3	Score on a scale
Borg Dyspnea Score	Placebo	Week 6	1.8	Standard Deviation 1.3	Score on a scale

1 to 10 of 24Source ClinicalTrials.gov

See all 24 results by group

Participant flow6

How many started, completed or left each group, period by period.

Period	Milestone	Group	Participants
Overall Study	STARTED	Sildenafil	37
Overall Study	STARTED	Placebo	37
Overall Study	COMPLETED	Sildenafil	15
Overall Study	COMPLETED	Placebo	14
Overall Study	NOT COMPLETED	Sildenafil	22
Overall Study	NOT COMPLETED	Placebo	23

Source ClinicalTrials.gov

Adverse events46

Each adverse event the trial posted, group by group: the participants affected out of those at risk.

Type	Event	Organ system	Group	Affected	At risk
other	SCA with Crisis	Congenital, familial and genetic disorders	Sildenafil	18	37
other	SCA with Crisis	Congenital, familial and genetic disorders	Placebo	13	37
other	Headache	Nervous system disorders	Sildenafil	13	37
other	Headache	Nervous system disorders	Placebo	4	37
other	Musculoskeletal and connective tissue disorders	Musculoskeletal and connective tissue disorders	Sildenafil	5	37
other	Musculoskeletal and connective tissue disorders	Musculoskeletal and connective tissue disorders	Placebo	6	37
other	Blood and Lymphatic system disorders	Blood and lymphatic system disorders	Sildenafil	4	37
other	Blood and Lymphatic system disorders	Blood and lymphatic system disorders	Placebo	6	37
other	Eye disorders	Eye disorders	Sildenafil	5	37
other	Eye disorders	Eye disorders	Placebo	4	37

1 to 10 of 46Source ClinicalTrials.gov

See all 46 adverse events

Adverse event totals6

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	Sildenafil
Total, all-cause mortality	Placebo
Total, other adverse events	Sildenafil	30
Total, other adverse events	Placebo	28
Total, serious adverse events	Sildenafil	17	37
Total, serious adverse events	Placebo	8	37

Source ClinicalTrials.gov

Papers12

The papers the trial lists on ClinicalTrials.gov.

PMID	Listed as	Source
2209119	BACKGROUND	PubMed
8074054	BACKGROUND	PubMed
8956017	BACKGROUND	PubMed
21527519	DERIVED	PubMed
21900080	DERIVED	PubMed
22983573	DERIVED	PubMed
24988120	DERIVED	PubMed
31322833	DERIVED	PubMed
34014839	DERIVED	PubMed
34990411	DERIVED	PubMed

1 to 10 of 12

See all 12 papers

Grants0

The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.

None in this release.

Trial comparisons1

Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.

Comparison
Sildenafil vs Placebo: serious adverse events

Source Trial comparisons

Tests0

The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.

None in this release.

Data dates

The day each source was copied for this release.

ClinicalTrials.gov: 2026-11-12; ClinicalTrials.gov
Results, from AACT: 2026-03-23; AACT
NIH grant links: 2026-11-13; NIH RePORTER

Sources 3

ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
ClinicalTrials.govNo license stated
NIH RePORTER's clinical studies and project filesPublic domain

Each source's terms

ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
ClinicalTrials.govnone stated
NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)

ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.

For software

Read this trial from software.

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