A Phase 2 interventional study of Double dose in Atrial Fibrillation, Venous Thromboembolism and Heart Valve Disease, sponsored by McMaster University. Completed at 1 site in Canada. Per ClinicalTrials.gov, last updated 2016-04-05.
Sponsored by McMaster University · Phase 2, Interventional, and Treatment
It is not known how to best restart warfarin after temporary withdrawal. Participants will be randomized to two groups. Group 1 will restart warfarin at their usual maintenance dose, group 2 will restart warfarin at double their maintenance dose for two days followed by their usual maintenance dose. The main outcome parameter will be the number of patients who are back in therapeutic INR (international normalized ratio) range 4, and 9 days after restarting anticoagulation with warfarin. Thromboembolic and/or bleeding events will be recorded as additional parameters. These data will be collected by a standardized telephone interview at 1 month. In addition, the investigators will evaluate a possible prothrombotic state by measuring the potential of thrombin generation and D-dimers in the subset of patients visiting HHS-General Hospital for their INR tests.
We will investigate if it is feasible to use double maintenance dose for the first two administrations of vitamin K antagonists when these drugs were temporarily interrupted and thus keep the time of an increased risk of thromboembolism and duration of "bridging" at a minimum. The control group will consist of patients who resume vitamin K antagonists at their usual maintenance dose. The aim of the study is to establish how to best restart anticoagulation with vitamin K antagonists after temporal withdrawal of these drugs. The main outcome parameter will be the proportion of patients who are back to a therapeutic international normalized ratio (INR) ratio at certain days after restarting vitamin K antagonists. Two additional parameters will be evaluated: Firstly, bleeding and thromboembolic complications will be reported and secondly, a possible prothrombotic state, measured as an elevation of D-dimer, at the initiation of anticoagulation will be evaluated.
3,870 studies on the registry are indexed under Atrial Fibrillation; 923 are open to participants now.
This study's enrollment of 104 is below the median of 144 across 2,380 interventional studies indexed under Atrial Fibrillation.
Browse Atrial Fibrillation studies →McMaster University is the lead sponsor of 720 studies on the registry; 124 are open to participants now.
Of its 6 completed or terminated interventional studies of FDA-regulated products, 2 (33%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Re-initiation with warfarin at twice the usual maintenance dose the first 2 days, then maintenance dose.
Drug: Double dose
Usual maintenance dose from Day 1, i.e. no postoperative loading dose.
For each individual the dose on Day 1 and Day 2 will be twice the one normally taken
Also known as: Loading dose
Proportion of patients with INR back in therapeutic range Day 5 or Day 10
Proportion of patients with INR 2.0-3.0 on Day 5 or Day 10 (day of invasive procedure defined as Day 1)
Time frame: Day 5-10
Thromboembolic events
Objectively verified arterial or venous thromboembolic events
Time frame: 30 days
Major bleeding events
Defined by the ISTH criteria of 2010
Time frame: 30 days
Minor bleeding events
Any bleeding requiring medical attention but not fulfilling the criteria of Major bleeding
Time frame: 30 days
Laboratory parameters of hypercoagulability
Quantitative D-dimer and Thrombin Generation performed in a subset at day of procedure, day 5 and 10 to identify abnormal rise.
Time frame: 10 days
Plan to share: No
This study is completed, as verified in Apr 2016. You cannot join it, but the record below documents what was studied.
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