Platelet AggregationPhase 4NCT00748371
Loss of Effect of Aspirin on Platelet Aggregation During Chronic Administration
A Phase 4 study testing aspirin in people with Platelet Aggregation, run by Vanderbilt University at 1 site in United States.
Trial summary
Aspirin has shown to be beneficial to some patients with certain diseases such as coronary artery disease or stroke. We are investigating how aspirin works on regulating platelets and thromboxane over time at different doses. Read more about this study
- Who is it for?
- Ages 18 years and older, men onlyHealthy volunteers can take part
- Conditions the study is for
- Platelet Aggregation
- What is being tested?
- aspirin
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 51 participants
- Where
- 1 siteUnited States
- Study dates
- Jun 2004to Feb 2011
- Phase
- Phase 4
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Men only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Males
- Age 18-40 years
- Non-smokers
Who cannot join
- ASA/NSAID use previous 14 days.
- Evidence of ASA/NSAID use within previous 14 days at baseline visit based on investigator interpretation of platelet aggregation and platelet secretion studies.
- History of chronic NSAID use.
- Currently taking NSAIDs, corticosteroids, or anticoagulants.
- History of coronary artery disease, myocardial infarction, coronary artery bypass grafting, percutaneous angioplasty, diabetes mellitus or stroke.
- History of gastric,duodenal, or esophageal ulcers or serious gastrointestinal bleed.
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- History of frequent headaches, pain syndrome, or other condition requiring frequent use of analgesics.
- History of adverse reaction to ASA.
- Initial platelet count <100K/µl or >500K/µl.
- Initial hematocrit <35% or >50%.
- Weight less than 110 pounds.
Trial locations and contacts
1 site in 1 country.
United States1 site
Vanderbilt University
Nashville, Tennessee, 37232-6602
About this study
Aspirin has shown to be beneficial to some patients with certain diseases such as coronary artery disease or stroke. We are investigating how aspirin works on regulating platelets and thromboxane over time at different doses. We hope to find the best dose of aspirin and/or other medications to help people who are at risk for heart attack or stroke.
Read the detailed description
he purpose of the study is to better understand the mechanism for failure of daily aspirin administration to prevent cardiovascular events in some at risk individuals. We seek to describe the effect of chronic aspirin administration at varying doses on platelet aggregation. This will help to define mechanisms for aspirin failure and to pursue possible alternative therapies in patients who fail to respond to aspirin therapy.
We hypothesize that (1) inhibition by aspirin (ASA) of ex vivo-induced platelet aggregation varies in a predictable time and dose dependent manner, (2) thromboxane and prostacyclin production is inhibited by ASA in a dose-dependent manner and remains relatively constant over time once maximal inhibition has occurred, and (3) granule secretion by platelets during induced aggregation is inhibited by aspirin acutely but this effect does not persist during chronic administration at high doses.
- Conditions
- Platelet Aggregation
- Being tested
- aspirin, placebo
- Keywords
- platelet aggregation, granule secretion, thromboxane production, prostacyclin production
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
aspirinDrug
Also called acetylsalicylic acid, ASA
40mg aspirin: one 40-mg aspirin capsule by mouth each morning + one Avicel capsule by mouth each evening
aspirinDrug
Also called acetylsalicylic acid, ASA
1300mg aspirin: one 650-mg capsule by mouth twice daily
placeboDrug
Also called Avicel, cellulose
Placebo: one Avicel (cellulose) capsule by mouth twice daily
| Study group | Role | What they receive |
|---|---|---|
| 1 | Experimental | ASA 40mg daily for 8 weeks followed by 3 weeks of observation Receives: Drug: aspirin |
| 2 | Experimental | ASA 1300mg daily for 8 weeks followed by 3 weeks of observation Receives: Drug: aspirin |
| 3 | Placebo comparator | Placebo: one Avicel (cellulose) capsule by mouth twice daily Receives: Drug: placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Comparison of platelet aggregation, serum thromboxane B2 (TxB2) levels, urinary thromboxane metabolite (Tx-M) levels, and urinary prostacyclin metabolite (PGI-M) levels over time and across dose ranges.
Measured: 11 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Sep 2008 (estimated)
- Study startJun 2004
- Primary completionFeb 2011
- Study completionFeb 2011
Why it stopped: Funding issue
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Platelet AggregationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 51 participants (actual)
Sponsor and investigators
- Lead sponsor
- Vanderbilt University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, John Oates, Vanderbilt University
- Investigators
- John A Oates, M.D., Principal investigator, Vanderbilt University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00748371
- Sponsor's protocol ID
- GM15431-JAO1
- Status last verified
- Apr 2017
- First submitted
- 5 Sep 2008
- Last updated
- 12 Apr 2017
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 12 Apr 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Loss of Effect of Aspirin on Platelet Aggregation During Chronic Administration
- ClinicalTrials.gov ID
- NCT00748371
- Acronym / sponsor ID
- GM15431-JAO1
- Conditions
- Platelet Aggregation
- Keywords
- platelet aggregation, granule secretion, thromboxane production, prostacyclin production
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Funding issue
- Enrolment
- 51 participants (actual)
- Lead sponsor
- Vanderbilt UniversityUniversity, hospital or other
- Study start
- Jun 2004
- Primary completion
- Feb 2011 (actual)
- Study completion
- Feb 2011 (actual)
- First posted
- 8 Sep 2008 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Aspirin has shown to be beneficial to some patients with certain diseases such as coronary artery disease or stroke. We are investigating how aspirin works on regulating platelets and thromboxane over time at different doses. We hope to find the best dose of aspirin and/or other medications to help people who are at risk for heart attack or stroke.
Detailed description
he purpose of the study is to better understand the mechanism for failure of daily aspirin administration to prevent cardiovascular events in some at risk individuals. We seek to describe the effect of chronic aspirin administration at varying doses on platelet aggregation. This will help to define mechanisms for aspirin failure and to pursue possible alternative therapies in patients who fail to respond to aspirin therapy.
We hypothesize that (1) inhibition by aspirin (ASA) of ex vivo-induced platelet aggregation varies in a predictable time and dose dependent manner, (2) thromboxane and prostacyclin production is inhibited by ASA in a dose-dependent manner and remains relatively constant over time once maximal inhibition has occurred, and (3) granule secretion by platelets during induced aggregation is inhibited by aspirin acutely but this effect does not persist during chronic administration at high doses.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| 1 | Experimental | Drug: aspirinASA 40mg daily for 8 weeks followed by 3 weeks of observation |
| 2 | Experimental | Drug: aspirinASA 1300mg daily for 8 weeks followed by 3 weeks of observation |
| 3 | Placebo comparator | Drug: placeboPlacebo: one Avicel (cellulose) capsule by mouth twice daily |
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Males
- Age 18-40 years
- Non-smokers
Key exclusion criteria (11 listed)
- ASA/NSAID use previous 14 days.
- Evidence of ASA/NSAID use within previous 14 days at baseline visit based on investigator interpretation of platelet aggregation and platelet secretion studies.
- History of chronic NSAID use.
- Currently taking NSAIDs, corticosteroids, or anticoagulants.
- History of coronary artery disease, myocardial infarction, coronary artery bypass grafting, percutaneous angioplasty, diabetes mellitus or stroke.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| aspirinAlso: acetylsalicylic acid, ASA40mg aspirin: one 40-mg aspirin capsule by mouth each morning + one Avicel capsule by mouth each evening | Drug | 1 |
| aspirinAlso: acetylsalicylic acid, ASA1300mg aspirin: one 650-mg capsule by mouth twice daily | Drug | 2 |
| placeboAlso: Avicel, cellulosePlacebo: one Avicel (cellulose) capsule by mouth twice daily | Drug | 3 |
Primary outcome
Comparison of platelet aggregation, serum thromboxane B2 (TxB2) levels, urinary thromboxane metabolite (Tx-M) levels, and urinary prostacyclin metabolite (PGI-M) levels over time and across dose ranges.
Time frame: 11 weeks
Results and safety
The study was stopped early (reason given: Funding issue). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Apr 2017.
- Individual participant dataSharing planned: No
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Cookies for Platelets
Blood Donation
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
John A Oates, M.D. principal investigator
Vanderbilt University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing aspirin in people with Platelet Aggregation, run by Vanderbilt University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 12 Apr 2017. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study was stopped early (reason given: Funding issue). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Comparison of platelet aggregation, serum thromboxane B2 (TxB2) levels, urinary thromboxane metabolite (Tx-M) levels, and urinary prostacyclin metabolite (PGI-M) levels over time and across dose ranges. (time frame: 11 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Apr 2017.