[1] Kanazawa Univ, Dept Thorac Cardiovasc & Gen Surg, 13-1 Takaramachi, Kanazawa, Ishikawa 9208641, Japan
[2] Univ Tokyo, Dept Healthcare Qual Assessment, Tokyo, Japan
[3] Toho Univ, Sakura Med Ctr, Dept Cardiovasc Surg, Sakura, Japan
[4] NewHeart Watanabe Inst, Dept Cardiovascu Surg, Tokyo, Japan
[5] Japan Cardiovasc Surg Database Org, Tokyo, Japan