title: Utility of d-dimer in the diagnosis of patients with chronic thromboembolic pulmonary hypertension.
abstract: BACKGROUND
  Chronic thromboembolic pulmonary hypertension (CTEPH) is an important cause of severe pulmonary hypertension (PH). D-dimer, a degradation product of fibrin, has been used as a marker for various diseases. In patients with idiopathic pulmonary arterial hypertension there is evidence to suggest that D-dimer levels are associated with disease severity; however, data regarding D-dimer in patients with CTEPH are lacking.
  
  
  OBJECTIVE
  To assess the significance of D-dimer in patients with CTEPH.
  
  
  METHODS
  Retrospective chart review of 618 patients seen at our PH clinic from 1991 to June 2008. Data collection focused on patients diagnosed with CTEPH, D-dimer levels, demographics, clinical, and hemodynamics. We compared D-dimer levels in CTEPH patients or World Health Organization (WHO) diagnostic group 4 with PH patients in WHO group 1.
  
  
  RESULTS
  Thirty-four patients with confirmed CTEPH were identified, of these 19 had D-dimer levels and 7 were positive. Of the 234 patients in WHO group 1 excluding patients with portopulmonary hypertension (n = 54) and pulmonary venoocclusive disease (n = 2) 97 had D-dimer levels and 52 were positive. We found an estimated sensitivity of the D-dimer test in diagnosing CTEPH was 37% while the estimated specificity was 46%. The positive predictive value and negative predictive value were 12% and 79% respectively.
  
  
  CONCLUSIONS
  D-dimer is an insensitive and nonspecific test for the diagnosis of CTEPH. Despite a high negative predictive value D-dimer alone cannot be used to rule out CTEPH in patients with PH.
authors: Division of Pulmonary Medicine, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
authors: Vichaya
authors: V
authors: Arunthari
authors: Charles D
authors: CD
authors: Burger