[1] Univ Minnesota, Div Cardiovasc, Minneapolis, MN 55455 USA
[2] LDS Hosp, Div Cardiol, Salt Lake City, UT USA
[3] LDS Hosp, Div Cardiothorac Surg, Salt Lake City, UT USA
[4] Advocate Christ Med Ctr, Div Cardiol, Oak Lawn, IL USA
[5] Advocate Christ Med Ctr, Div Cardiothorac Surg, Oak Lawn, IL USA
[6] Duke Univ, Med Ctr, Div Cardiol, Durham, NC USA
[7] Duke Univ, Med Ctr, Div Cardiothorac Surg, Durham, NC USA