[1] Baystate Med Ctr, Heart & Vasc Program, 759 Chestnut St, Springfield, MA 01199 USA
[2] Montreal Heart Inst, Montreal, PQ, Canada
[3] WakeMed Hlth & Hosp, Raleigh, NC USA
[4] Centennial Heart & Vasc Ctr, Nashville, TN USA
[5] Univ Manitoba, St Boniface Hosp, Winnipeg, MB, Canada
[6] Cleveland Clin, Cleveland, OH 44106 USA
[7] MemorialCare Heart & Vasc Inst, Los Angeles, CA USA
[8] Franciscan Hlth Heart Ctr, Indianapolis, IN USA
[9] Duke Univ, Sch Med, Durham, NC USA
[10] Atrium Hlth, Dept Cardiovasc & Thorac Surg, Greensboro, NC USA
[11] St Georges Univ London, London, England
[12] CHU Vaudois, Cardiac Surg Ctr, Lausanne, Switzerland
[13] Univ Calgary, Calgary, AB, Canada
[14] St Charles Hosp, Dept Cardiac Surg, Bend, OR USA
[15] Univ Manitoba, Max Rady Coll Med, Dept Surg, Winnipeg, MB, Canada
[16] Baystate Med Ctr, Dept Surg, Springfield, MA 01107 USA