title: Left atrial size is a potent predictor of mortality in mitral regurgitation due to flail leaflets: results from a large international multicenter study.
abstract: BACKGROUND
  Left atrium (LA) enlargement is common in organic mitral regurgitation (MR) and is an emerging prognostic indicator. However, outcome implications of LA enlargement have not been analyzed in the context of routine clinical practice and in a multicenter study.
  
  
  RESULTS
  The Mitral Regurgitation International DAtabase (MIDA) registry enrolls patients with organic MR due to flail leaflets, diagnosed in routine clinical practice, in 5 US and European centers. We investigated the relation between LA diameter and mortality under medical treatment and after mitral surgery in 788 patients in sinus rhythm (64±12 years; median LA, 48 [43 to 52] mm). LA diameter was independently associated with survival after diagnosis (hazard ratio, 1.08 [1.04 to 1.12] per 1 mm increment). Compared with patients with LA <55 mm, those with LA ≥55 mm had lower 8-year overall survival (P<0.001). LA ≥55 mm independently predicted overall mortality (hazard ratio, 3.67 [1.95 to 6.88]) and cardiac mortality (hazard ratio, 3.74 [1.72 to 8.13]) under medical treatment. The association of LA ≥55 mm and mortality was consistent in subgroups. Similar excess mortality associated with LA ≥55 mm was observed in asymptomatic and symptomatic patients (P for interaction, 0.77). In patients who underwent mitral surgery, LA ≥55 mm had no impact on postoperative outcome (P>0.20). Mitral surgery was associated with greater survival benefit in patients with LA ≥55 mm compared with LA <55 mm (P for interaction, 0.008).
  
  
  CONCLUSIONS
  In MR caused by flail leaflets, LA diameter ≥55 mm is associated with increased mortality under medical treatment, independent of the presence of symptoms or left ventricular dysfunction.
authors: INSERM, ERI 12 and University Hospital Amiens, France.
authors: Dan
authors: D
authors: Rusinaru
authors: Christophe
authors: C
authors: Tribouilloy
authors: Francesco
authors: F
authors: Grigioni
authors: Jean François
authors: JF
authors: Avierinos
authors: Rakesh M
authors: RM
authors: Suri
authors: Andrea
authors: A
authors: Barbieri
authors: Catherine
authors: C
authors: Szymanski
authors: Marinella
authors: M
authors: Ferlito
authors: Hector
authors: H
authors: Michelena
authors: Laurence
authors: L
authors: Tafanelli
authors: Francesca
authors: F
authors: Bursi
authors: Sonia
authors: S
authors: Mezghani
authors: Angelo
authors: A
authors: Branzi
authors: Gilbert
authors: G
authors: Habib
authors: Maria G
authors: MG
authors: Modena
authors: Maurice
authors: M
authors: Enriquez-Sarano
mesh_terms: D000368:Aged; D016279:Atrial Function, Left / Q000502:physiology*; D002423:Cause of Death / Q000639:trends; D018450:Disease Progression; D015150:Echocardiography, Doppler / Q000379:methods*; D005060:Europe / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000401:mortality* / Q000503:physiopathology; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D015996:Survival Rate / Q000639:trends; D014481:United States / Q000453:epidemiology