[1] Univ Toronto, St Michaels Hosp, Div Cardiac Surg, 8th Floor,Bond Wing,30 Bond St, Toronto, ON M5B 1W8, Canada
[2] Duke Natl Univ Singapore, Med Sch, Natl Heart Ctr Singapore, Singapore, Singapore
[3] Univ Med Ctr Groningen, Dept Cardiol, Groningen, Netherlands
[4] George Inst Global Hlth, Sydney, NSW, Australia
[5] St Lukes Mid Amer Heart Inst, Kansas City, MO USA
[6] Univ Missouri, Kansas City, MO 64110 USA