[1] Univ Pittsburgh, Dept Cardiothorac Surg, Div Cardiac Surg, Pittsburgh, PA USA
[2] Univ Pittsburgh, UPMC Heart & Vasc Inst, Med Ctr, Pittsburgh, PA USA
[3] Harvard Med Sch, Massachusetts Gen Hosp, Div Cardiac Surg, Boston, MA USA
[4] Katholieke Univ Leuven, Leuven, Belgium
[5] Harvard Med Sch, Massachusetts Gen Hosp, Div Cardiol, Boston, MA USA