[1] Univ Pittsburgh, Dept Cardiothorac Surg, Pittsburgh, PA USA
[2] Rochester Reg Hlth, Rochester, NY USA
[3] Univ Penn, Dept Surg, Div Cardiovasc Surg, Philadelphia, PA 19104 USA
[4] Stanford Univ, Dept Cardiothorac Surg, Stanford, CA 94305 USA
[5] Med Univ South Carolina, Dept Surg, Div Cardiothorac Surg, Charleston, SC 29425 USA