[1] St Georges Univ London, London, England
[2] Univ Perugia, Sch Med, I-06100 Perugia, Italy
[3] Univ Oslo, Ulleval Hosp, Oslo, Norway
[4] Univ Oslo, Oslo, Norway
[5] AZ Klina, Brasschaat, Belgium
[6] Harvard Univ, Sch Med, Boston, MA USA
[7] Thrombosis Res Inst, London SW3 6LR, England
[8] Osaka Natl Hosp, Inst Clin Res, Natl Hosp Org, Osaka, Japan
[9] McMaster Univ, Hamilton, ON, Canada