[1] Univ Hosp Ioannina, Sch Med, Dept Cardiothorac Surg, Ioannina, Greece
[2] Inst Mutualiste Montsouris, Dept Cardiac Surg, Paris, France
[3] Univ Hosp Patras, Sch Med, Dept Cardiothorac Surg, Patras, Greece
[4] Univ Hosp Ioannina, Sch Med, Dept Anesthesiol, Ioannina, Greece