[1] Brigham & Womens Hosp, Div Cardiovasc, Boston, MA 02115 USA
[2] Ochsner Med Ctr, Div Cardiovasc, New Orleans, LA USA
[3] Univ Montreal, Montreal, PQ, Canada
[4] ANMCO, Florence, Italy
[5] Univ Glasgow, Western Infirm, Glasgow G11 6NT, Lanark, Scotland
[6] Duke Univ, Med Ctr, Durham, NC USA