Atrial FibrillationPhase 4Dabi-ADP-1NCT01339819
Impact of Dabigatran and Phenprocoumon on ADP Induced Platelet Aggregation in Patients With Atrial Fibrillation
A Phase 4 study testing Dabigatran and Phenprocoumon in people with Atrial Fibrillation, run by Deutsches Herzzentrum Muenchen at 1 site in Germany.
Trial summary
The aim of this study is to evaluate whether Dabigatran itself reduces ADP induced platelet aggregation measured by MEA as compared to Phenprocoumon after a two-week treatment with either agent. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Atrial Fibrillation
- What is being tested?
- Dabigatran and Phenprocoumon
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 70 participants
- Where
- 1 siteGermany
- Study dates
- Apr 2011to Sep 2012
- 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
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients with atrial fibrillation and an indication for oral anticoagulation (CHA2DS2-VASc score≥ 1).
- Informed, written consent by the patient or her/his legally-authorized representative for participation in the study.
Who cannot join
- Age ≤18 years
- Cardiogenic shock
- Current therapy with dabigatran
- Current, recent (2 weeks) or expected (1 week) clopidogrel therapy
- Contraindication for oral anticoagulation
- Active bleeding
- Known allergy or intolerance to the study medications: dabigatran, phenprocoumon
Trial locations and contacts
1 site in 1 country.
About this study
The aim of this study is to evaluate whether Dabigatran itself reduces ADP induced platelet aggregation measured by MEA as compared to Phenprocoumon after a two-week treatment with either agent.
Read the detailed description
Oral anticoagulation with vitamin K antagonists (OAC) is the standard care for reducing stroke in patients with atrial fibrillation. Just recently the direct, competitive thrombin inhibitor dabigatran has been approved by the FDA for stroke prevention in patients with atrial fibrillation. In a large multicenter trial it was shown that dabigatran was at least as effective as Vitamin K antagonists in the prevention of stroke without an increase of major hemorrhage.
Approximately 6 % of patients who undergo coronary stenting and need DAT with aspirin and clopidogrel need in addition OAC for the reduction of cardiac, cerebral and systemic thromboembolic events. These patients will therefore need triple therapy, a therapy which is associated with increased bleeding complications. Although phenprocoumon given solely without clopidogrel has no impact on ADP induced platelet aggregation, it has been shown that phenprocoumon significantly attenuates the antiplatelet effects of clopidogrel.
ADP induced platelet aggregation measured with multiple electrode platelet aggregometry (MEA) is a marker for the efficacy of the clopidogrel therapy and (i) a low response (AUC ≥ 468) to clopidogrel has been associated with an increase of ischemic events such as stent thrombosis and (ii) patients with an enhanced response to clopidogrel (AUC ≤ 188) have higher bleeding rates.
It is therefore crucial to evaluate whether an additional antithrombotic therapy such as dabigatran alters ADP induced platelet aggregation in these patients. While it has been shown that intravenous administration of the direct thrombin inhibitor bivalirudin further reduces ADP induced platelet aggregation in patients on clopidogrel therapy, it is unknown whether dabigatran has also an impact on ADP induced platelet aggregation.
To evaluate the impact of dabigatran on ADP induced platelet aggregation we will randomize patients with atrial fibrillation and the need for oral anticoagulation for a two-week treatment with either dabigatran or phenprocoumon and we hypothesize that dabigatran is superior to phenprocoumon in the reduction of ADP induced platelet aggregation. Patients who are concomitantly treated with clopidogrel are being studied in a different trial with a similar study design (Dabi ADP-2).
- Conditions
- Atrial Fibrillation
- Being tested
- Dabigatran, Phenprocoumon
- Medical subject headings
- Atrial Fibrillation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DabigatranDrug
Also called Pradaxa
Patients assigned to this group will receive Dabigatran
PhenprocoumonDrug
Also called Marcumar
Patients assigned to this group will receive Phenprocoumon
| Study group | Role | What they receive |
|---|---|---|
| Arm 1 | Experimental | Dabigatran Therapy Receives: Drug: Dabigatran |
| Arm 2 | Active comparator | Phenprocoumon Therapy Receives: Drug: Phenprocoumon |
What is being measured
The primary outcome is the main question the study is designed to answer.
ADP induced platelet aggregation
To determine whether there are differences in ADP induced platelet aggregation after 2 weeks in patients receiving dabigatran or phenprocoumon.
Measured: 2 weeks
Secondary outcomes (2)
Platelet function tests
ADPtest HS (MEA) , TRAP, Collagen
Measured: 2 weeks
Coagulation parameters
aPTT, INR, Thrombin coagulation time
Measured: 2 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Apr 2011 (estimated)
- Study startApr 2011
- Primary completionMay 2012
- Study completionSep 2012
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Atrial FibrillationStudies 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
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 70 participants (actual)
Sponsor and investigators
- Lead sponsor
- Deutsches Herzzentrum Muenchen
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Julinda Mehilli, MD, Principal investigator, Deutsches Herzzentrum München, Klinik für Herz- und Kreislauferkrankungen
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01339819
- Sponsor's protocol ID
- GE IDE No. A01611
- Other IDs
- 2011-000503-40
- Acronym
- Dabi-ADP-1
- Status last verified
- Jul 2013
- First submitted
- 15 Apr 2011
- Last updated
- 2 Jul 2013
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Jul 2013. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of Dabigatran and Phenprocoumon on ADP Induced Platelet Aggregation in Patients With Atrial Fibrillation
- ClinicalTrials.gov ID
- NCT01339819
- Acronym / sponsor ID
- Dabi-ADP-1 / GE IDE No. A01611
- Conditions
- Atrial Fibrillation
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 70 participants (actual)
- Lead sponsor
- Deutsches Herzzentrum MuenchenUniversity, hospital or other
- Study start
- Apr 2011
- Primary completion
- May 2012 (actual)
- Study completion
- Sep 2012 (actual)
- First posted
- 21 Apr 2011 (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.
The aim of this study is to evaluate whether Dabigatran itself reduces ADP induced platelet aggregation measured by MEA as compared to Phenprocoumon after a two-week treatment with either agent.
Detailed description
Oral anticoagulation with vitamin K antagonists (OAC) is the standard care for reducing stroke in patients with atrial fibrillation. Just recently the direct, competitive thrombin inhibitor dabigatran has been approved by the FDA for stroke prevention in patients with atrial fibrillation. In a large multicenter trial it was shown that dabigatran was at least as effective as Vitamin K antagonists in the prevention of stroke without an increase of major hemorrhage.
Approximately 6 % of patients who undergo coronary stenting and need DAT with aspirin and clopidogrel need in addition OAC for the reduction of cardiac, cerebral and systemic thromboembolic events. These patients will therefore need triple therapy, a therapy which is associated with increased bleeding complications. Although phenprocoumon given solely without clopidogrel has no impact on ADP induced platelet aggregation, it has been shown that phenprocoumon significantly attenuates the antiplatelet effects of clopidogrel.
ADP induced platelet aggregation measured with multiple electrode platelet aggregometry (MEA) is a marker for the efficacy of the clopidogrel therapy and (i) a low response (AUC ≥ 468) to clopidogrel has been associated with an increase of ischemic events such as stent thrombosis and (ii) patients with an enhanced response to clopidogrel (AUC ≤ 188) have higher bleeding rates.
It is therefore crucial to evaluate whether an additional antithrombotic therapy such as dabigatran alters ADP induced platelet aggregation in these patients. While it has been shown that intravenous administration of the direct thrombin inhibitor bivalirudin further reduces ADP induced platelet aggregation in patients on clopidogrel therapy, it is unknown whether dabigatran has also an impact on ADP induced platelet aggregation.
To evaluate the impact of dabigatran on ADP induced platelet aggregation we will randomize patients with atrial fibrillation and the need for oral anticoagulation for a two-week treatment with either dabigatran or phenprocoumon and we hypothesize that dabigatran is superior to phenprocoumon in the reduction of ADP induced platelet aggregation. Patients who are concomitantly treated with clopidogrel are being studied in a different trial with a similar study design (Dabi ADP-2).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Arm 1 | Experimental | Drug: DabigatranDabigatran Therapy |
| Arm 2 | Active comparator | Drug: PhenprocoumonPhenprocoumon Therapy |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Patients with atrial fibrillation and an indication for oral anticoagulation (CHA2DS2-VASc score≥ 1).
- Informed, written consent by the patient or her/his legally-authorized representative for participation in the study.
Key exclusion criteria (7 listed)
- Age ≤18 years
- Cardiogenic shock
- Current therapy with dabigatran
- Current, recent (2 weeks) or expected (1 week) clopidogrel therapy
- Contraindication for oral anticoagulation
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 |
|---|---|---|
| DabigatranAlso: PradaxaPatients assigned to this group will receive Dabigatran | Drug | Arm 1 |
| PhenprocoumonAlso: MarcumarPatients assigned to this group will receive Phenprocoumon | Drug | Arm 2 |
Primary outcome
ADP induced platelet aggregation
Time frame: 2 weeks
To determine whether there are differences in ADP induced platelet aggregation after 2 weeks in patients receiving dabigatran or phenprocoumon.
2 secondary outcomes
Platelet function tests
Time frame: 2 weeks
Coagulation parameters
Time frame: 2 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Jul 2013.
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Concomitant Left Atrial Appendage Closure and Pulsed Field Ablation-Asia
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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.
Julinda Mehilli, MD principal investigator
Deutsches Herzzentrum München, Klinik für Herz- und Kreislauferkrankungen
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 Dabigatran and Phenprocoumon in people with Atrial Fibrillation, run by Deutsches Herzzentrum Muenchen at 1 site in Germany.
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 2 inclusion and 7 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 2 Jul 2013. 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 Germany. 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.
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 is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
ADP induced platelet aggregation (time frame: 2 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 2 Jul 2013.