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Dabigatran Versus Warfarin After Mitral and/or Aortic Bioprosthesis Replacement and Atrial Fibrillation Postoperatively (DAWA)

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: NCT01868243
Recruitment Status : Terminated (because a significant decrease of viable candidates for the study.)
First Posted : June 4, 2013
Results First Posted : October 9, 2015
Last Update Posted : October 9, 2015
Information provided by (Responsible Party):
Andre Duraes, PhD, Hospital Ana Nery

Brief Summary:
DAWA is a phase 2, prospective, open-label, randomized, pilot study. The main variable to be observed in this study is intracardiac thrombus. There are no formal primary or secondary clinical efficacy or safety outcomes because it is a pilot study.

Condition or disease Intervention/treatment Phase
Primary Disease Drug: Dabigatran Drug: Warfarin Phase 2 Phase 3

Detailed Description:

Mortality and morbidity events (reversible ischemic neurological deficit, ischemic and hemorrhagic stroke, systemic embolism, any bleeding, prosthesis valve thrombosis and death) were evaluated in an exploratory manner. The details of the trial design have been previously described.8 The trial protocol was approved by the local ethics and research committee in the city of Salvador-Brazil, and written informed consent was obtained from all patients. An independent data and safety monitoring board closely monitored the trial. All the members contributed to the interpretation of the results, wrote the first version of the manuscript and approved all versions, made the decision to submit the manuscript for publication, and vouch for the accuracy and completeness of the data reported and the fidelity of this article to the study protocol.

Patients eligible for inclusion in the study were 18 to 64 years old, underwent mitral and/or aortic bioprosthesis valve replacement at least 3 months prior to entering the study and had documented AF postoperatively in addition to exclusion of atrial thrombus or valve prosthesis thrombosis by transesophageal echocardiography (TEE). Non-contrast brain computed tomography (CT) without hemorrhage or findings of acute cerebral infarction on the last 2 days of screening was also necessary.

Patients were randomly assigned to receive dabigatran or warfarin by a computer generated list of random numbers performed to 1:1 ratio between the groups. Following that, the allocation sequence was concealed from the researcher enrolling participants in sequentially numbered, opaque, black, sealed envelopes. After randomization, patients had study visits scheduled at 7 days (via telephone) and at 30 days (personally) with a monthly follow-up for 90 days. After this, non-contrast brain CT and TEE were repeated. The former was executed to document possible cerebral events with no clinical expression and the latter to analyze the incidence of intracardiac thrombi, new dense spontaneous echo contrast (SEC) or its resolution, in addition to thrombosis or dysfunction of valvular prosthesis.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 27 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Dabigatran Versus Warfarin After Mitral and Aortic Bioprosthesis Replacement for the Management of Atrial Fibrillation Postoperatively: Pilot Study
Study Start Date : August 2013
Actual Primary Completion Date : September 2014
Actual Study Completion Date : October 2014

Arm Intervention/treatment
Experimental: Dabigatran
Dabigatran 110 mg BID
Drug: Dabigatran
Group 1 - Dabigatran 110 mg (50 patients)
Other Name: Pradaxa® (dabigatran etexilate) 110mg twice daily

Active Comparator: Warfarin
Warfarin adjusted-dose
Drug: Warfarin
Warfarin adjusted-dose
Other Name: Warfarin adjusted-dose

Primary Outcome Measures :
  1. Intracardiac Thrombus [ Time Frame: 90 days ]
    The primary endpoint was the detection of intracardiac thrombus in TEE at the end of follow-up (90 days).

Secondary Outcome Measures :
  1. Spontaneous Echo Contrast [ Time Frame: 90 days ]
    Spontaneous Echo Contrast showed in Transesophageal echocardiography

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 64 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Age from 18 to 64 years at entry
  2. Patients with mitral and/or aorthic valve bioprosthesis for at least 3 months postoperatively
  3. There is 12-lead electrocardiogram documented AF on the day of screening or randomization; or a 24-hour Holter electrocardiogram recording showing AF episodes postoperatively
  4. Brain computed tomography scan without hemorrhage or findings of acute cerebral infarction on the last 2 days of screening
  5. Exclusion of atrial thrombus or valve prosthesis thrombosis by transesophageal echocardiograph on the last 2 days of screening
  6. Written, informed consent

Exclusion Criteria:

  1. Previous hemorrhagic stroke
  2. Ischemic stroke in the last 6 months
  3. Severe renal impairment (creatinine clearance rates < 30 ml/min)
  4. Active liver disease (any etiology)
  5. Concomitant use of any antiplatelet (aspirin, clopidogrel, prasugrel, ticagrelor, ticlopidine, etc)
  6. Increased risk of bleeding (congenital or acquired)
  7. Uncontrolled hypertension
  8. Gastrointestinal hemorrhage within the past year
  9. Anemia (hemoglobin level <10 g/dL) or thrombocytopenia (platelet count < 100 × 109/L)
  10. Active infective endocarditis
  11. Pregnant or lactating women

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01868243

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Hospital Ana Nery
Salvador, Bahia, Brazil, 40320010
Sponsors and Collaborators
Hospital Ana Nery
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Principal Investigator: Andre R Duraes, Professor Hospital Ana Nery
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Andre Duraes, PhD, Andre Rodrigues Duraes, Hospital Ana Nery Identifier: NCT01868243    
Other Study ID Numbers: DAWA2013
First Posted: June 4, 2013    Key Record Dates
Results First Posted: October 9, 2015
Last Update Posted: October 9, 2015
Last Verified: September 2015
Keywords provided by Andre Duraes, PhD, Hospital Ana Nery:
Atrial Fibrillation
Additional relevant MeSH terms:
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Atrial Fibrillation
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes
Serine Proteinase Inhibitors
Protease Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action