[1] Lankenau Inst Med Res, Dept Cardiac Surg Res, Wynnewood, PA 19096 USA
[2] Univ Manitoba, St Boniface Hosp, Cardiac Surg Dept, Winnipeg, MB, Canada
[3] Univ Brescia, Spedali Civili Brescia, Dept Cardiac Surg, Brescia, Italy
[4] Yale Sch Med, Dept Surg, Sect Cardiac Surg, New Haven, CT USA
[5] Univ Padua, Cardiac Surg Dept, Padua, Italy
[6] Univ Calgary, Libin Cardiovasc Inst, Dept Cardiac Surg, Calgary, AB, Canada
[7] Univ Firenze, Clin & Expt Med Dept, Florence, Italy
[8] Univ Kentucky, Dept Cardiac Surg, Appalachian Reg Hlth, Hazard, KY USA
[9] Univ Siena, Dept Cardiol, Siena, Italy
[10] Main Line Hlth, Lankenau Med Ctr, Lankenau Heart Inst, Dept Cardiac Surg, Wynnewood, PA USA
[11] Weill Cornell Univ, Dept Cardiac Surg, New York, NY USA