[1] Kyoto Univ, Dept Cardiovasc Med, Grad Sch Med, Kyoto, Japan
[2] Tenri Hosp, Dept Cardiol, Tenri, Nara, Japan
[3] Massachusetts Gen Hosp, Cardiol Div, Boston, MA 02114 USA
[4] Shiga Med Ctr Adults, Dept Cardiol, Moriyama, Japan
[5] Hyogo Coll Med, Dept Clin Epidemiol, Nishinomiya, Hyogo, Japan
[6] Kitano Hosp, Dept Cardiol, Osaka, Japan