Aortic Valve DiseaseTissue-ValveNCT00465218
Transcranial Doppler (TCD) Assessment During Early Anti-thrombotic Therapy After Bioprosthetic Aortic Valve Replacement
An observational study of Aortic Valve Disease, run by Ottawa Heart Institute Research Corporation at 1 site in Canada.
Trial summary
The purpose of this study is to determine if there is any difference in the counts of cerebral emboli and platelet function between two prophylactic treatments of thrombosis currently used at University of Ottawa Heart Institute for the first three months after surgery in low-risk patients undergoing aortic valve… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Aortic Valve Disease
- What is being tested?
- Prophylaxis of Thrombosis after aortic valve replacement
- Type of treatment
- Surgery or procedure
- How many people
- 70 participants
- Where
- 1 siteCanada
- Study dates
- Mar 2007to Mar 2011
- Phase
- Observational
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients with aortic valve stenosis and/or insuficiency undergoing aortic valve replacement with a bioprosthetic valve (tissue valve).
Who may be able to join
- Patients undergoing primary aortic valve replacement with bioprosthetic (tissue) valve.
Who cannot join
- Emergency surgery or redo operations.
- Patients with history of transient ischemic attacks, stroke, or history of carotid stenosis greater than 50% as detected by carotid duplex doppler or angiography.
- Patients with COPD who are CO2 retainers.
- Patients with LV function less than 50%, or enlarged left ventricle greater than 50 mm as detected by echocardiography or previous history of thromboembolism.
- Patients with history of atrial fibrillation or heart rhythm disturbances.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: "Transcranial Doppler Assessment of Cerebral Embolization During Early Anti-thrombotic Therapy After Bioprosthetic Aortic Valve Replacement: Comparison of High-dose Aspirin Versus Warfarin Plus Low-dose Aspirin"
The purpose of this study is to determine if there is any difference in the counts of cerebral emboli and platelet function between two prophylactic treatments of thrombosis currently used at University of Ottawa Heart Institute for the first three months after surgery in low-risk patients undergoing aortic valve replacement with a bioprosthetic valve: 1) daily use of high-dose aspirin [325 mgs], and 2) the combination of oral Warfarin [target INR 2.0 to 3.0] and low-dose aspirin [81 mg].
Read the detailed description
Background:
There are several medications used to prevent blood clotting in patients undergoing surgical replacement of their aortic valves with tissue valves. One of these medications is called warfarin (Coumadin ®) which prevents blood clotting by making the blood "thinner." Another medication is aspirin which prevents the aggregation (clustering) of cells in the blood called platelets. Some clinicians consider that using only aspirin should be enough to protect the patients against the presence of clots in the blood, but others consider that aspirin should be combined with warfarin for better protection. Moreover, physicians express concern over the use of oral anticoagulation due to the possibility of an increased risk of bleeding. The effects of these medications for preventing blood clots traveling to the brain after the surgery are currently unknown. Transcranial doppler ultrasound will be used in these patients to evaluate non-invasively the quantity of fragments of clots circulating in the arteries of the brain. In addition, platelet function will be measured to determine how effective these treatments are for preventing the aggregation of the blood cells called platelets, which may be involved in clot formation.
Objective:
Our purpose is to determine if there is any difference in the counts of cerebral emboli and platelet function between two prophylactic treatments of thrombosis currently used in our institution for the first three months after surgery in these patients: 1) daily use of high-dose aspirin [325 mgs], and 2) the combination of oral Warfarin [target INR 2.0 to 3.0] and low-dose aspirin [81 mg].
Methods:
Patients with low risk profile undergoing primary aortic valve replacement with a bioprosthetic (tissue) valve will be eligible for the study. Patients will receive one of the two prophylactic treatments of thrombosis (1 or 2) depending on the surgeon's preference. Platelet function will be measured before surgery and transcranial doppler within the first 24 hours immediately after the surgery. At the end of one month following surgery, all patients will undergo transcranial doppler and platelet function assessment. The study will be powered on demonstrating the hypothesis of substantial equivalence between the two treatments as regarding the primary outcome (cerebral emboli).
Outcome measures:
- Primary outcome: Bilateral counts of cerebral emboli in the middle cerebral arteries with transcranial doppler ultrasound at one month after surgery
- Secondary outcomes:
Platelet function, incidence of major adverse neurologic and bleeding events at one month following surgery
- Conditions
- Aortic Valve Disease
- Being tested
- Prophylaxis of Thrombosis after aortic valve replacement
- Keywords
- Bioprosthesis, Thrombosis, Cerebral emboli, Transcranial Doppler, Platelet function tests
- Medical subject headings
- Aortic Valve Disease, Thrombosis, Intracranial Embolism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Prophylaxis of Thrombosis after aortic valve replacementProcedure or surgery
Two standard prophylactic treatments of thrombosis within the first 3 months postsurgery currently used in our institution: a) daily dose of aspirin (325 mgs; b) daily dose of aspirin (81 mg) plus Warfarin for target INR 2.0-2.5
| Study group | Role | What they receive |
|---|---|---|
| 1 | High dose aspirin (325 mg) Receives: Procedure: Prophylaxis of Thrombosis after aortic valve replacement | |
| 2 | Low dose aspirin (81 mgs) plus warfarin Receives: Procedure: Prophylaxis of Thrombosis after aortic valve replacement |
What is being measured
The primary outcome is the main question the study is designed to answer.
Differences in the Rate of Doppler-detected Cerebral Micro Emboli Between the Two Prophylactic Treatments of Thrombosis
Trans-cranial doppler (TCD) measurements were used to test for the presence of cerebral micro-emboli. Doppler measurements were completed on the neck and throughout the temporal window. In addition, probes were secure to the temporal areas with a headband. Measurements determined presence of air or solid emboli.
Each participant at the 1 month visit underwent TCD measurements after 30min of exposure to room air, and again 30min after receiving 100% oxygen through a breathing mask. Results show the comparison of participants on aspirin only vs warfarin + aspirin when TCD was completed both in room air and with 100% oxygen.
Measured: 1 month after surgery
Secondary outcomes (2)
Differences in the Degree of Inhibition of Platelet Aggregation Between the Two Prophylactic Treatments of Thrombosis
Measured: 1 month after surgery
Difference in the Degree of Inhibitor of Platelet Aggregation Between the Two Prophylactic Treatments of Thrombosis
Measured: 1 month after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Apr 2007 (estimated)
- Study startMar 2007
- Primary completionDec 2007
- Study completionMar 2011
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (12)Papers the sponsor has linked to this study.
- Other trials for Aortic Valve DiseaseStudies of the same condition, open and under way.
- More trials run by Ottawa Heart Institute Research CorporationThe sponsor's other registered studies.
- 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
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 70 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ottawa Heart Institute Research Corporation
- Sponsor type
- University, hospital or other
- Collaborators
- Edwards Lifesciences
- Responsible party
- Sponsor
- Investigators
- Marc Ruel, MD, MPH, Principal investigator, Ottawa Heart Institute Research CorporationThierry Mesana, MD, PhD, Study director, Ottawa Heart Institute Research Corporation
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00465218
- Sponsor's protocol ID
- 2006785-01H
- Acronym
- Tissue-Valve
- Status last verified
- Mar 2021
- First submitted
- 20 Apr 2007
- Last updated
- 22 May 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
Publications
Gohlke-Barwolf C, Acar J, Oakley C, Butchart E, Burckhart D, Bodnar E, Hall R, Delahaye JP, Horstkotte D, Kremer R, et al. Guidelines for prevention of thromboembolic events in valvular heart disease. Study Group of the Working Group on Valvular Heart Disease of the European Society of Cardiology. Eur Heart J. 1995 Oct;16(10):1320-30. doi: 10.1093/oxfordjournals.eurheartj.a060739. No abstract available.
PubMed 8746900ACC/AHA guidelines for the management of patients with valvular heart disease. A report of the American College of Cardiology/American Heart Association. Task Force on Practice Guidelines (Committee on Management of Patients with Valvular Heart Disease). J Am Coll Cardiol. 1998 Nov;32(5):1486-588. doi: 10.1016/s0735-1097(98)00454-9. No abstract available.
PubMed 9809971Stein PD, Alpert JS, Bussey HI, Dalen JE, Turpie AG. Antithrombotic therapy in patients with mechanical and biological prosthetic heart valves. Chest. 2001 Jan;119(1 Suppl):220S-227S. doi: 10.1378/chest.119.1_suppl.220s.
PubMed 11157651Kirtane AJ, Rahman AM, Martinezclark P, Jeremias A, Seto TB, Manning WJ. Adherence to American College of Cardiology/American Heart Association guidelines for the management of anticoagulation in patients with mechanical valves undergoing elective outpatient procedures. Am J Cardiol. 2006 Mar 15;97(6):891-3. doi: 10.1016/j.amjcard.2005.09.139. Epub 2006 Feb 2.
PubMed 16516596Heras M, Chesebro JH, Fuster V, Penny WJ, Grill DE, Bailey KR, Danielson GK, Orszulak TA, Pluth JR, Puga FJ, et al. High risk of thromboemboli early after bioprosthetic cardiac valve replacement. J Am Coll Cardiol. 1995 Apr;25(5):1111-9. doi: 10.1016/0735-1097(94)00563-6.
PubMed 7897124Moinuddeen K, Quin J, Shaw R, Dewar M, Tellides G, Kopf G, Elefteriades J. Anticoagulation is unnecessary after biological aortic valve replacement. Circulation. 1998 Nov 10;98(19 Suppl):II95-8; discussion II98-9.
PubMed 9852888Gherli T, Colli A, Fragnito C, Nicolini F, Borrello B, Saccani S, D'Amico R, Beghi C. Comparing warfarin with aspirin after biological aortic valve replacement: a prospective study. Circulation. 2004 Aug 3;110(5):496-500. doi: 10.1161/01.cir.0000137122.95108.52.
PubMed 15289387Rodriguez RA, Rubens F, Rodriguez CD, Nathan HJ. Sources of variability in the detection of cerebral emboli with transcranial Doppler during cardiac surgery. J Neuroimaging. 2006 Apr;16(2):126-32. doi: 10.1111/j.1552-6569.2006.00035.x.
PubMed 16629734Zimmermann N, Roussiekan T, Winter J, Kurt M, Gams E, Wenzel F, Hohlfeld T. Platelet inhibition by aspirin after aortic valve replacement. J Thorac Cardiovasc Surg. 2006 Jun;131(6):1392-3. doi: 10.1016/j.jtcvs.2006.01.029. No abstract available.
PubMed 16733175Geiser T, Sturzenegger M, Genewein U, Haeberli A, Beer JH. Mechanisms of cerebrovascular events as assessed by procoagulant activity, cerebral microemboli, and platelet microparticles in patients with prosthetic heart valves. Stroke. 1998 Sep;29(9):1770-7. doi: 10.1161/01.str.29.9.1770.
PubMed 9731593Sturzenegger M, Beer JH, Rihs F. Monitoring combined antithrombotic treatments in patients with prosthetic heart valves using transcranial Doppler and coagulation markers. Stroke. 1995 Jan;26(1):63-9. doi: 10.1161/01.str.26.1.63.
PubMed 7839399Markus HS, Thomson ND, Brown MM. Asymptomatic cerebral embolic signals in symptomatic and asymptomatic carotid artery disease. Brain. 1995 Aug;118 ( Pt 4):1005-11. doi: 10.1093/brain/118.4.1005.
PubMed 7655877
Study at a glance
From the registry record, last updated by the sponsor on 22 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- "Transcranial Doppler Assessment of Cerebral Embolization During Early Anti-thrombotic Therapy After Bioprosthetic Aortic Valve Replacement: Comparison of High-dose Aspirin Versus Warfarin Plus Low-dose Aspirin"
- ClinicalTrials.gov ID
- NCT00465218
- Acronym / sponsor ID
- Tissue-Valve / 2006785-01H
- Conditions
- Aortic Valve Disease
- Keywords
- Bioprosthesis, Thrombosis, Cerebral emboli, Transcranial Doppler, Platelet function tests
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 70 participants (actual)
- Lead sponsor
- Ottawa Heart Institute Research CorporationUniversity, hospital or other
- Collaborators
- Edwards Lifesciences
- Study start
- Mar 2007
- Primary completion
- Dec 2007 (actual)
- Study completion
- Mar 2011 (actual)
- First posted
- 24 Apr 2007 (estimated)
- Results
- Posted 22 May 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to determine if there is any difference in the counts of cerebral emboli and platelet function between two prophylactic treatments of thrombosis currently used at University of Ottawa Heart Institute for the first three months after surgery in low-risk patients undergoing aortic valve replacement with a bioprosthetic valve: 1) daily use of high-dose aspirin [325 mgs], and 2) the combination of oral Warfarin [target INR 2.0 to 3.0] and low-dose aspirin [81 mg].
Detailed description
Background:
There are several medications used to prevent blood clotting in patients undergoing surgical replacement of their aortic valves with tissue valves. One of these medications is called warfarin (Coumadin ®) which prevents blood clotting by making the blood "thinner." Another medication is aspirin which prevents the aggregation (clustering) of cells in the blood called platelets. Some clinicians consider that using only aspirin should be enough to protect the patients against the presence of clots in the blood, but others consider that aspirin should be combined with warfarin for better protection. Moreover, physicians express concern over the use of oral anticoagulation due to the possibility of an increased risk of bleeding. The effects of these medications for preventing blood clots traveling to the brain after the surgery are currently unknown. Transcranial doppler ultrasound will be used in these patients to evaluate non-invasively the quantity of fragments of clots circulating in the arteries of the brain. In addition, platelet function will be measured to determine how effective these treatments are for preventing the aggregation of the blood cells called platelets, which may be involved in clot formation.
Objective:
Our purpose is to determine if there is any difference in the counts of cerebral emboli and platelet function between two prophylactic treatments of thrombosis currently used in our institution for the first three months after surgery in these patients: 1) daily use of high-dose aspirin [325 mgs], and 2) the combination of oral Warfarin [target INR 2.0 to 3.0] and low-dose aspirin [81 mg].
Methods:
Patients with low risk profile undergoing primary aortic valve replacement with a bioprosthetic (tissue) valve will be eligible for the study. Patients will receive one of the two prophylactic treatments of thrombosis (1 or 2) depending on the surgeon's preference. Platelet function will be measured before surgery and transcranial doppler within the first 24 hours immediately after the surgery. At the end of one month following surgery, all patients will undergo transcranial doppler and platelet function assessment. The study will be powered on demonstrating the hypothesis of substantial equivalence between the two treatments as regarding the primary outcome (cerebral emboli).
Outcome measures:
- Primary outcome: Bilateral counts of cerebral emboli in the middle cerebral arteries with transcranial doppler ultrasound at one month after surgery
- Secondary outcomes:
Platelet function, incidence of major adverse neurologic and bleeding events at one month following surgery
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 1 | – | Procedure: Prophylaxis of Thrombosis after aortic valve replacementHigh dose aspirin (325 mg) |
| 2 | – | Procedure: Prophylaxis of Thrombosis after aortic valve replacementLow dose aspirin (81 mgs) plus warfarin |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with aortic valve stenosis and/or insuficiency undergoing aortic valve replacement with a bioprosthetic valve (tissue valve).
Key inclusion criteria (1 listed)
- Patients undergoing primary aortic valve replacement with bioprosthetic (tissue) valve.
Key exclusion criteria (5 listed)
- Emergency surgery or redo operations.
- Patients with history of transient ischemic attacks, stroke, or history of carotid stenosis greater than 50% as detected by carotid duplex doppler or angiography.
- Patients with COPD who are CO2 retainers.
- Patients with LV function less than 50%, or enlarged left ventricle greater than 50 mm as detected by echocardiography or previous history of thromboembolism.
- Patients with history of atrial fibrillation or heart rhythm disturbances.
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 |
|---|---|---|
| Prophylaxis of Thrombosis after aortic valve replacementTwo standard prophylactic treatments of thrombosis within the first 3 months postsurgery currently used in our institution: a) daily dose of aspirin (325 mgs; b) daily dose of aspirin (81 mg) plus Warfarin for target INR 2.0-2.5 | Procedure or surgery | 1, 2 |
Primary outcome
Differences in the Rate of Doppler-detected Cerebral Micro Emboli Between the Two Prophylactic Treatments of Thrombosis
Time frame: 1 month after surgery
Trans-cranial doppler (TCD) measurements were used to test for the presence of cerebral micro-emboli. Doppler measurements were completed on the neck and throughout the temporal window. In addition, probes were secure to the temporal areas with a headband. Measurements determined presence of air or solid emboli. Each participant at the 1 month visit underwent TCD measurements after 30min of exposure to room air, and again 30min after receiving 100% oxygen through a breathing mask. Results show the comparison of participants on aspirin only vs warfarin + aspirin when TCD was completed both in room air and with 100% oxygen.
2 secondary outcomes
Differences in the Degree of Inhibition of Platelet Aggregation Between the Two Prophylactic Treatments of Thrombosis
Time frame: 1 month after surgery
Difference in the Degree of Inhibitor of Platelet Aggregation Between the Two Prophylactic Treatments of Thrombosis
Time frame: 1 month after surgery
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 May 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Background: PubMed 8746900Gohlke-Barwolf C, Acar J, Oakley C, Butchart E, Burckhart D, Bodnar E, Hall R, Delahaye JP, Horstkotte D, Kremer R, et al. Guidelines for prevention of thromboembolic events in valvular heart disease. Study Group of the Working Group on Valvular Heart Disease of the European Society of Cardiology. Eur Heart J. 1995 Oct;16(10):1320-30. doi: 10.1093/oxfordjournals.eurheartj.a060739. No abstract available.
- Background: PubMed 9809971ACC/AHA guidelines for the management of patients with valvular heart disease. A report of the American College of Cardiology/American Heart Association. Task Force on Practice Guidelines (Committee on Management of Patients with Valvular Heart Disease). J Am Coll Cardiol. 1998 Nov;32(5):1486-588. doi: 10.1016/s0735-1097(98)00454-9. No abstract available.
- Background: PubMed 11157651Stein PD, Alpert JS, Bussey HI, Dalen JE, Turpie AG. Antithrombotic therapy in patients with mechanical and biological prosthetic heart valves. Chest. 2001 Jan;119(1 Suppl):220S-227S. doi: 10.1378/chest.119.1_suppl.220s.
- Background: PubMed 16516596Kirtane AJ, Rahman AM, Martinezclark P, Jeremias A, Seto TB, Manning WJ. Adherence to American College of Cardiology/American Heart Association guidelines for the management of anticoagulation in patients with mechanical valves undergoing elective outpatient procedures. Am J Cardiol. 2006 Mar 15;97(6):891-3. doi: 10.1016/j.amjcard.2005.09.139. Epub 2006 Feb 2.
- Background: PubMed 7897124Heras M, Chesebro JH, Fuster V, Penny WJ, Grill DE, Bailey KR, Danielson GK, Orszulak TA, Pluth JR, Puga FJ, et al. High risk of thromboemboli early after bioprosthetic cardiac valve replacement. J Am Coll Cardiol. 1995 Apr;25(5):1111-9. doi: 10.1016/0735-1097(94)00563-6.
- Background: PubMed 9852888Moinuddeen K, Quin J, Shaw R, Dewar M, Tellides G, Kopf G, Elefteriades J. Anticoagulation is unnecessary after biological aortic valve replacement. Circulation. 1998 Nov 10;98(19 Suppl):II95-8; discussion II98-9.
- Background: PubMed 15289387Gherli T, Colli A, Fragnito C, Nicolini F, Borrello B, Saccani S, D'Amico R, Beghi C. Comparing warfarin with aspirin after biological aortic valve replacement: a prospective study. Circulation. 2004 Aug 3;110(5):496-500. doi: 10.1161/01.cir.0000137122.95108.52.
- Background: PubMed 16629734Rodriguez RA, Rubens F, Rodriguez CD, Nathan HJ. Sources of variability in the detection of cerebral emboli with transcranial Doppler during cardiac surgery. J Neuroimaging. 2006 Apr;16(2):126-32. doi: 10.1111/j.1552-6569.2006.00035.x.
- Background: PubMed 16733175Zimmermann N, Roussiekan T, Winter J, Kurt M, Gams E, Wenzel F, Hohlfeld T. Platelet inhibition by aspirin after aortic valve replacement. J Thorac Cardiovasc Surg. 2006 Jun;131(6):1392-3. doi: 10.1016/j.jtcvs.2006.01.029. No abstract available.
- Background: PubMed 9731593Geiser T, Sturzenegger M, Genewein U, Haeberli A, Beer JH. Mechanisms of cerebrovascular events as assessed by procoagulant activity, cerebral microemboli, and platelet microparticles in patients with prosthetic heart valves. Stroke. 1998 Sep;29(9):1770-7. doi: 10.1161/01.str.29.9.1770.
- Background: PubMed 7839399Sturzenegger M, Beer JH, Rihs F. Monitoring combined antithrombotic treatments in patients with prosthetic heart valves using transcranial Doppler and coagulation markers. Stroke. 1995 Jan;26(1):63-9. doi: 10.1161/01.str.26.1.63.
- Background: PubMed 7655877Markus HS, Thomson ND, Brown MM. Asymptomatic cerebral embolic signals in symptomatic and asymptomatic carotid artery disease. Brain. 1995 Aug;118 ( Pt 4):1005-11. doi: 10.1093/brain/118.4.1005.
- Publications indexed to this studyLink provided by the sponsor.
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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.
Marc Ruel, MD, MPH principal investigator
Ottawa Heart Institute Research Corporation
Thierry Mesana, MD, PhD study director
Ottawa Heart Institute Research Corporation
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Aortic Valve Disease, run by Ottawa Heart Institute Research Corporation at 1 site in Canada.
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 1 inclusion and 5 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: finished, as of the sponsor's last update on 22 May 2026. 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 Canada. 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 22 May 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
Differences in the Rate of Doppler-detected Cerebral Micro Emboli Between the Two Prophylactic Treatments of Thrombosis (time frame: 1 month after surgery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00465218, which also lists 12 linked publications.
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 22 May 2026.