Research: International Projects

Multinational Study of Oral Vitamin K
OVWAC VI study; a multi-center, multinational study of oral vitamin K for the treatment of warfarin associated coagulopathy
Director: Prof. Walter Ageno

Warfarin is a highly effective anticoagulant, but it often causes bleeding, which may be fatal.
The risk of bleeding in an individual is increased by a number of factors. The single strongest predictor of hemorrhage is excessive prolongation of the international normalized ratio (INR).
Large studies suggest patients spend 10 to 20 percent of their time with excessively prolonged INR values. No studies using clinical end-points have ever been conducted to assess the optimal management of warfarin associated coagulopathy.

In this multi-center, multinational study we aimed to prove that low dose oral vitamin K can reduce the risk of bleeding, without causing thrombosis, in patients with warfarin associated coagulopathy.
To demonstrate the effectiveness of vitamin K, this study will enroll patients with INR values of more than 4.5 and will allocate them to receive 1.25 mg vitamin K or placebo (if their INR is less than 10.0) or 2.5 mg vitamin K (if their INR is greater than 10.0). The study will enroll a total of 660 patients in approximately 15 participating centers in Italy, US, and Canada.

Visiting Professors:

1) Prof. Mark Crowther, Department of Hematology, McMaster University, Ontario, Canada

2) Prof. Bruno Caramelli, Department of Cardiology, University of Sao Paulo, Sao Paulo, Brazil

Visiting Professors during conferences:

1) Prof. Alexander G.G. Turpie, Department of Medicine, McMaster University, Ontario, Canada

2) Prof. Mark Crowther, Department of Hematology, McMaster University, Ontario, Canada

3) Prof. Giancarlo Agnelli, Department of Medicine, University of Perugia

4) Prof. Gualtiero Palareti, Department of Angiology, University of Bologna

5) Prof. Sergio Siragusa, Department of Hematology, University of Palermo