[1] Sahlgrens Univ Hosp, Dept Cardiothorac Surg, Bla Straket 5,plan 5, S-41345 Gothenburg, Sweden
[2] Univ Gothenburg, Inst Med, Sahlgrenska Acad, Dept Mol & Clin Med, Gothenburg, Sweden
[3] Sahlgrens Univ Hosp, Dept Cardiol, Gothenburg, Sweden
[4] Univ Turku, Dept Surg & Clin Med, Turku, Finland
[5] Cent Finland Hosp Nova, Dept Surg, Jyvaskyla, Finland
[6] South Alvsborg Hosp, Dept Med, Boras, Sweden