title: The variable natural history of idiopathic dilated cardiomyopathy.
abstract: BACKGROUND
  Determining the prognosis of patients with heart failure is essential for patient management and clinical trial conduct. The relative value of traditional prognostic criteria remains unclear and the assessment of long-term prognosis for individual patients is problematic.
  
  
  OBJECTIVE
  To determine the ability of clinical, hemodynamic and echocardiographic parameters to predict the long-term prognosis of patients with idiopathic dilated cardiomyopathy.
  
  
  METHODS
  We investigated the ability of clinical, hemodynamic and echocardiographic parameters to predict the long-term prognosis of individual patients in a large, representative, contemporary cohort of idiopathic dilated cardiomyopathy (IDCM) patients referred to Johns Hopkins from 1997 to 2004 for evaluation of cardiomyopathy. In all patients a baseline history was taken, and physical examination, laboratory studies, echocardiogram, right heart catheterization and endomyocardial biopsy were performed.
  
  
  RESULTS
  In 171 IDCM patients followed for a median 3.5 years, there were 50 long-term event-free survivors (LTS) (median survival 6.4 years) and 34 patients died or underwent ventricular assist device placement or transplantation within 5 years (NLTS; non-long-term survivors) (median time to event 1.83 years. Established risk factors (gender, race, presence of diabetes, serum creatinine, sodium) and the use of accepted heart failure medications (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta blockers) were similar between the two groups. Although LTS had younger age, higher ejection fraction (EF) and lower New York Heart Association (NYHA) class at presentation, the positive predictive value of an EF < 25% was 64% (95% CI 41%-79%) and that of NYHA class > 2 was 53% (95% CI 36-69%). A logistic model incorporating these three variables incorrectly classified 29% of patients.
  
  
  CONCLUSIONS
  IDCM exhibits a highly variable natural history and standard clinical predictors have limited ability to classify IDCM patients into broad prognostic categories. These findings suggest that there are important host-environmental factors still unappreciated in the biology of IDCM.
authors.affiliation: Department of Medicine, Johns Hopkins Bayview Medical Center, Baltimore, MD, USA.
authors.forename: Kapil
authors.initials: K
authors.lastname: Parakh
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Kittleson
authors.forename: Bettina
authors.initials: B
authors.lastname: Heidecker
authors.forename: Ilan S
authors.initials: IS
authors.lastname: Wittstein
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Judge
authors.forename: Hunter C
authors.initials: HC
authors.lastname: Champion
authors.forename: Lili A
authors.initials: LA
authors.lastname: Barouch
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Baughman
authors.forename: Stuart D
authors.initials: SD
authors.lastname: Russell
authors.forename: Edward K
authors.initials: EK
authors.lastname: Kasper
authors.forename: Kranthi K
authors.initials: KK
authors.lastname: Sitammagari
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Hare
mesh_terms: D001706:Biopsy; D006328:Cardiac Catheterization; D002311:Cardiomyopathy, Dilated / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D003404:Creatinine / Q000097:blood; D003937:Diagnosis, Differential; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index
chemical_list: D003404:Creatinine