title: Impact of atrial fibrillation on outcome of patients with idiopathic dilated cardiomyopathy: data from the Heart Muscle Disease Registry of Trieste.
abstract: OBJECTIVE
  There is a paucity and inconsistency of data regarding the natural history of patients affected by idiopathic dilated cardiomyopathy (IDCM) and atrial fibrillation (AF). We examined the prognostic implications of AF in a subset of patients with IDCM.
  
  
  METHODS
  We analyzed the data of 539 patients with IDCM enrolled in the Heart Muscle Disease Registry of Trieste.
  
  
  RESULTS
  At baseline, 52 (9.6%) of 539 patients had AF. There was no difference in survival of patients with either AF or sinus rhythm at enrollment (P = .28). During long-term follow-up (90 ± 58 months), AF was detected on ECG/ECG-Holter monitoring in 28 (5.7%) of 487 patients in sinus rhythm at baseline. Predictors of new onset of AF at multivariate analysis were a more dilated left atrium (OR 1.35, 95% CI 1.06-1.72; P = .01) and a lower left ventricle ejection fraction (for 10% decrease, OR 2.41, 95% CI 1.24-4.69, P = .016). Patients developing AF had higher mortality/heart transplantation rate compared to patients who maintained sinus rhythm during follow-up (P < .001). At multivariate analysis, new onset AF (HR 3.67, 95% CI 2.07-6.5; P < .001) in the first three years after diagnosis, but not baseline AF, was found to be independently associated with a worse outcome.
  
  
  CONCLUSIONS
  Atrial fibrillation is relatively frequent in patients with IDCM. The early development of AF during follow-up, but not its presence at baseline, is associated with poor survival.
authors.affiliation: Cardiovascular Department, Ospedali Riuniti, University of Trieste, Trieste, Italy. aaleksova@gmail.com
authors.forename: Aneta
authors.initials: A
authors.lastname: Aleksova
authors.forename: Marco
authors.initials: M
authors.lastname: Merlo
authors.forename: Massimo
authors.initials: M
authors.lastname: Zecchin
authors.forename: Gastone
authors.initials: G
authors.lastname: Sabbadini
authors.forename: Giulia
authors.initials: G
authors.lastname: Barbati
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Vitrella
authors.forename: Andrea
authors.initials: A
authors.lastname: Di Lenarda
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Sinagra
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000150:complications / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology* / Q000601:surgery; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000401:mortality* / Q000503:physiopathology* / Q000601:surgery; D018572:Disease-Free Survival; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D016027:Heart Transplantation; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D012042:Registries; D013318:Stroke Volume; D015996:Survival Rate; D014184:Transplantation, Homologous