title: Do semi-rigid prosthetic rings affect left ventricular function after mitral valve repair?
abstract: BACKGROUND
  After reports of cardiac impairment caused by mitral annuloplasty with rigid rings, several prosthetic rings with semi-rigidity were introduced. The influence of semi-rigid rings on postoperative cardiac function remains unknown. This study compared postoperative cardiac function between patients receiving a semi-rigid prosthetic ring and those receiving a flexible ring or band.
  
  
  RESULTS
  Transthoracic echocardiographic data of 305 patients who underwent mitral valve repair for degenerative mitral regurgitation (227 patients receiving a semi-rigid ring and 78 receiving a flexible ring or band) were retrospectively reviewed. The imbalance in the preoperative characteristics between groups was adjusted with propensity score matching. Left ventricular ejection fraction, end-diastolic dimension, and end-systolic dimension were compared at 1 week, 6 months, and 1 year after surgery. Propensity score matching yielded 68 matched pairs of patients for whom there were few group differences in preoperative covariates. Between patients receiving a semi-rigid ring and those receiving a flexible ring or band in the propensity-matched cohorts, there were no significant differences in ejection fraction (P=0.322), end-diastolic dimension (P=0.576), or end-systolic dimension (P=0.567).
  
  
  CONCLUSIONS
  There was little difference in the influence on postoperative cardiac function between semi-rigid rings and flexible rings or bands.
authors.affiliation: Department of Cardiovascular Surgery, Teikyo University Hospital, Tokyo, Japan. s-manabe@fb3.so-net.ne.jp
authors.forename: Susumu
authors.initials: S
authors.lastname: Manabe
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kasegawa
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Fukui
authors.forename: Minoru
authors.initials: M
authors.lastname: Tabata
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Shinozaki
authors.forename: Tomoki
authors.initials: T
authors.lastname: Shimokawa
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Takanashi
mesh_terms: D000328:Adult; D004452:Echocardiography; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D058386:Mitral Valve Annuloplasty; D012189:Retrospective Studies; D013318:Stroke Volume; D016277:Ventricular Function, Left