Prolongation of the Interval Between Prothrombin Time Tests in Stable Patients II
NCT01654042 · Status: WITHDRAWN · Phase: PHASE3 · Type: INTERVENTIONAL
Last updated 2014-03-20
Summary
More than 2 million patients in North America are treated with warfarin - a "blood thinner" - to prevent blood clots in arteries or veins. The treatment has to be monitored with a blood test and the dose changed accordingly every 1-4 weeks. One third of the patients have very stable results and hardly ever have to change the dose. The investigators wish to show that the level of control of the treatment with warfarin in these very stable patients is not worse with 12-weekly testing. A pilot study the investigators performed indicated that 12-weekly testing would be safe but this has to be confirmed in a large study. One third of patients taking warfarin have not had any changes in the dose for the past 6 months or longer. These patients will be asked about participation in the study. They will be randomized to testing and dosing every 4 or 12 weeks. Each patient is in the study until it ends, which will be minimum 1 year and can be up to about 4 years. The study is designed to show that 12-weekly testing does not significantly increase the risk for major bleeding or blood clots. The results would be important for a large number of patients. An increase of the interval between blood tests from 4 to 12 weeks would reduce the burden for these patients on life-long treatment considerably.
Conditions
- Atrial Fibrillation
- Valvular Heart Disease
- Deep Vein Thrombosis
- Pulmonary Embolism
- Peripheral Arterial Disease
Interventions
- OTHER
-
Prolonged interval between PT testing
Patients in the intervention group will be scheduled for prothrombin time testing and dosing of warfarin every 12 weeks instead of every 4 weeks. This has been suggested in the latest edition of the ACCP guidelines as a possibility for very stable patients. In order to change this from a suggestion to a formal recommendation a study powered for clinically important outcomes is needed.
Sponsors & Collaborators
- lead OTHER
Principal Investigators
-
Sam Schulman, MD, PhD · McMaster University
Study Design
- Allocation
- RANDOMIZED
- Purpose
- TREATMENT
- Masking
- NONE
- Model
- PARALLEL
Eligibility
- Min Age
- 18 Years
- Sex
- ALL
- Healthy Volunteers
- No
Timeline & Regulatory
- Start
- 2014-04-30
- Primary Completion
- 2018-04-30
- Completion
- 2018-10-31
Countries
- Canada
Study Locations
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