[1] Univ Calgary, Sect Cardiac Surg, Libin Cardiovasc Inst Alberta, Cumming Sch Med, Calgary, AB, Canada
[2] Univ Toronto, Div Cardiac Surg, Li Ka Shing Knowledge Inst, St Michaels Hosp, Toronto, ON, Canada
[3] Northwestern Univ, Martha & Richard Melman Family Bicuspid Aort Valv, Bluhm Cardiovasc Inst, Chicago, IL 60611 USA