[1] Univ Hosp South Manchester NHS Trust, Inst Cardiovasc Sci, Acad Dept Surg, Manchester M23 9LT, Lancs, England
[2] Univ Manchester, Sch Nursing Midwifery & Social Work, Manchester M13 9PL, Lancs, England
[3] Univ Manchester, St Marys Hosp, Inst Canc Sci, Manchester M13 9WL, Lancs, England
[4] Univ Manchester, Univ S Manchester Hosp, Educ & Res Ctr, Inst Cardiovasc Sci,Acad Surg Unit, Manchester M23 9LT, Lancs, England