[1] Hokkaido Univ, Fac Med, Dept Cardiovasc Med, Kita 15,Nishi 7,Kita Ku, Sapporo, Hokkaido 0608638, Japan
[2] Hokkaido Univ, Grad Sch Med, Kita 15,Nishi 7,Kita Ku, Sapporo, Hokkaido 0608638, Japan
[3] Kushiro City Gen Hosp, Dept Cardiovasc Med, Kushiro, Hokkaido, Japan
[4] Univ Miyazaki Hosp, Clin Res Support Ctr, Miyazaki, Japan
[5] Hokkaido Univ, Fac Med, Dept Resp Med, Sapporo, Japan