title: A population-based study of mortality among patients with atrial fibrillation or flutter.
abstract: OBJECTIVE
  To determine the mortality associated with atrial flutter and atrial fibrillation in the general population.
  
  
  METHODS
  Using the Marshfield Epidemiologic Study Area, a database that captures nearly all medical care and deaths among its 58,820 residents, we identified patients diagnosed with atrial flutter or atrial fibrillation from July 1, 1991, through June 30, 1995. Patients were followed prospectively and compared with a group of controls without these arrhythmias.
  
  
  RESULTS
  A total of 4775 person-years of follow-up were completed in 577 patients and 577 controls. Compared with controls, mortality among patients with atrial fibrillation or flutter was nearly 7.8-fold higher at 6 months (95% confidence interval [CI]: 4.1 to 15) and 2.5-fold higher (95% CI: 2.0 to 3.1; P < 0.0001) at the last follow-up (mean [+/- SD] of 3.6 +/- 2.3 years; range, 1 day to 7.3 years). At 6 months, mortality among patients with atrial flutter alone was somewhat greater than in controls and less than one third that of those with atrial fibrillation (with or without atrial flutter) (P = 0.02). At the last follow-up, however, mortality was greater among patients with atrial flutter (hazard ratio [HR] = 1.7; 95% CI: 1.2 to 2.6; P = 0.007), atrial fibrillation (HR = 2.4; 95% CI: 1.9 to 3.1; P < 0.0001), or both atrial arrhythmias (HR = 2.5; 95% CI: 1.9 to 3.3; P < 0.0001) when compared with controls in models that adjusted for cardiovascular risk factors.
  
  
  CONCLUSIONS
  In the general population, both atrial flutter and atrial fibrillation are independent predictors of increased late mortality. The relatively benign course during the 6-month period after the initial diagnosis of atrial flutter suggests that early diagnosis and treatment of these patients may improve their long-term survival.
authors.affiliation: Marshfield Clinic and St. Joseph's Hospital, Marshfield, Wisconsin, USA. vidaillet.humberto@marshfieldclinic.org
authors.forename: Humberto
authors.initials: H
authors.lastname: Vidaillet
authors.forename: Juan F
authors.initials: JF
authors.lastname: Granada
authors.forename: P o-Huang
authors.initials: Po
authors.lastname: Chyou
authors.forename: Karen
authors.initials: K
authors.lastname: Maassen
authors.forename: Mario
authors.initials: M
authors.lastname: Ortiz
authors.forename: Juan N
authors.initials: JN
authors.lastname: Pulido
authors.forename: Param
authors.initials: P
authors.lastname: Sharma
authors.forename: Peter N
authors.initials: PN
authors.lastname: Smith
authors.forename: John
authors.initials: J
authors.lastname: Hayes
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000401:mortality*; D001282:Atrial Flutter / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D015996:Survival Rate; D013997:Time Factors; D014922:Wisconsin / Q000453:epidemiology