title: Etiology of aortic valve disease and recent changes in Japan:a study of 600 valve replacement cases.
abstract: BACKGROUND
  Recent studies on the etiology of aortic valve disease in the US showed a decrease in rheumatic valve disease and an increase in age-related degenerative disease. The purpose of this study was to describe the etiology of aortic valve disease and its temporal changes in Japan, based on a large number of cases.
  
  
  METHODS
  The medical charts of all patients who underwent aortic valve replacement at our institute between 1977 and 1999 were reviewed. Among the 600 patients analyzed, 213 (36%) had pure aortic stenosis, 265 (44%) had pure aortic regurgitation, and 122 (20%) had combined stenosis and regurgitation.
  
  
  RESULTS
  The causes were rheumatic change (49%), degenerative change (19%), bicuspid valves (18%), infective endocarditis (5%) and others (9%). Rheumatic disease continued to be the most common cause of aortic stenosis, but its frequency decreased from 100% in 1977-1979 to 37% in 1995-1999. In contrast, the frequency of degenerative change among stenotic valves increased recently from 11% in 1990-1994 to 30% in 1995-1999. Similarly, rheumatic disease remained to be the leading cause of aortic regurgitation, with a decline in frequency from 46% in 1985-1989 to 27% in 1995-1999. The percentage of degenerative change among regurgitant valves did not change appreciably.
  
  
  CONCLUSIONS
  There was a shift in the causes of aortic valve disease, with a decrease in rheumatic disease and an increase in degenerative disease. This trend was similar to that observed in the US. These findings suggest the increasing importance of aortic valve disease due to degenerative change.
authors.affiliation: Department of Cardiology, Sakakibara Heart Institute, 2-5-4, Yoyogi, Shibuya-ku, Tokyo 151-0053, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Matsumura
authors.forename: Eiji
authors.initials: E
authors.lastname: Ohtaki
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Misu
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tohbaru
authors.forename: Ryuta
authors.initials: R
authors.lastname: Asano
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nagayama
authors.forename: Koichi
authors.initials: K
authors.lastname: Kitahara
authors.forename: Jun
authors.initials: J
authors.lastname: Umemura
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sumiyoshi
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Kawase
authors.forename: Takao
authors.initials: T
authors.lastname: Ida
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kasegawa
authors.forename: Saichi
authors.initials: S
authors.lastname: Hosoda
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001022:Aortic Valve Insufficiency / Q000453:epidemiology* / Q000209:etiology* / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000453:epidemiology* / Q000209:etiology* / Q000601:surgery; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012621:Seasons; D013997:Time Factors