title: Atrial fibrillation complicating the course of degenerative mitral regurgitation: determinants and long-term outcome.
abstract: OBJECTIVE
  The study was done to define the incidence, determinants and prognostic implications of onset of atrial fibrillation (AF) during follow-up of mitral regurgitation (MR) initially in sinus rhythm.
  
  
  BACKGROUND
  The rates and clinical implications of AF in MR are undefined.
  
  
  METHODS
  We analyzed the occurrence of AF under conservative management in two populations of patients with degenerative MR in sinus rhythm at diagnosis: 1) 360 patients (65 +/- 13 years, 74% men) with MR due to flail leaflets; and 2) 89 residents of Olmsted County, Minnesota (67 +/- 17 years, 56% men) with grade 3 or 4 MR due to simple mitral valve prolapse (MVP) diagnosed echocardiographically.
  
  
  RESULTS
  In patients with MR due to flail leaflets, AF rates at 5 and 10 years were 18 +/- 3% and 48 +/- 6%, respectively, and the linearized rate was 5.0 +/- 0.7% per year. Development of AF during follow-up was independently associated with high risk of cardiac death or heart failure (adjusted risk ratio 2.23, p = 0.025). The AF rate at 10 years was higher in patients >or=65 years (75 +/- 10% vs. 24 +/- 6%, p < 0.0001) and in those with baseline left atrial (LA) dimension >or=50 mm (67 +/- 8% vs. 37 +/- 9%, p < 0.001). In multivariate analysis, independent baseline predictors of AF were age and LA diameter (both p < 0.01). In patients with MR due to MVP, similar rates of AF (41 +/- 7% vs. 44 +/- 6% at nine years, p > 0.50) and predictors of AF (age and LA dimension, both p < 0.006) were noted.
  
  
  CONCLUSIONS
  In patients with degenerative MR in sinus rhythm at diagnosis, the incidence of AF occurring under conservative management is high and similar whether the cause of MR is flail leaflet or simple MVP. After onset of AF, an increased cardiac mortality and morbidity are both observed under conservative management. The risk of AF increases with advancing age and larger LA dimension. These data suggest that the clinical management of MR should take into account the high incidence, excess risk, and predictors of AF.
authors.affiliation: Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Francesco
authors.initials: F
authors.lastname: Grigioni
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Avierinos
authors.forename: Lieng H
authors.initials: LH
authors.lastname: Ling
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Scott
authors.forename: Kent R
authors.initials: KR
authors.lastname: Bailey
authors.forename: A Jamil
authors.initials: AJ
authors.lastname: Tajik
authors.forename: Robert L
authors.initials: RL
authors.lastname: Frye
authors.forename: Maurice
authors.initials: M
authors.lastname: Enriquez-Sarano
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications* / Q000453:epidemiology; D016022:Case-Control Studies; D015984:Causality; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008944:Mitral Valve Insufficiency / Q000150:complications* / Q000000981:diagnostic imaging / Q000453:epidemiology; D015999:Multivariate Analysis; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors