[1] Cleveland Clin, Miller Heart & Vasc Inst, Cleveland, OH 44106 USA
[2] Virginia Cardiac Serv Qual Initiat, Virginia Beach, VA USA
[3] Virginia Commonwealth Univ, Dept Surg, Div Cardiothorac Surg, Richmond, VA USA
[4] Univ Virginia, Dept Surg, Div Thorac & Cardiovasc Surg, Charlottesville, VA USA
[5] INOVA Heart & Vasc Inst, Falls Church, VA USA