[1] City Hosp Birmingham, Univ Dept Med, Haemostasis Thrombosis &Vasc Biol Unit, Birmingham B18 7QH, W Midlands, England
[2] City Hosp Birmingham, Dept Vasc Surg, Birmingham B18 7QH, W Midlands, England
[3] Univ Birmingham, Dept Primary Care & Gen Practice, Birmingham, W Midlands, England