title: Red cell distribution width is increased in chronic thromboembolic pulmonary hypertension.
abstract: BACKGROUND
  Chronic thromboembolic pulmonary hypertension (CTEPH) is a life-threatening condition characterized by single or recurrent pulmonary embolisms, which promotes pulmonary vascular remodeling. There is significant relationship between red cell distribution width (RDW) and pulmonary hypertension; however, the usefulness of RDW as biomarker for the diagnosis of CTEPH remains poorly defined.
  
  
  OBJECTIVE
  This study sought to assess the change and the diagnostic value of RDW in CTEPH.
  
  
  METHODS
  This retrospective study included 56 CTEPH patients and 56 sex- and age-matched healthy controls treated at Beijing Chao-Yang Hospital. Correlations between RDW and hematological and hemodynamic parameters were assessed. A logistic regression model was applied to test independent parameters in relation to the diagnosis of CTEPH, and receiver operating characteristic curve was plotted to determine the diagnostic value of RDW in CTEPH.
  
  
  RESULTS
  RDW values were significantly higher in CTEPH patients (13.82% ± 1.14%) compared with healthy controls (12.75% ± 0.49%) and in World Health Organization (WHO), functional class III-IV cases (14.39% ± 1.24%) compared with class I-II cases (13.32% ± 0.78%) (both P = 0.000). RDW levels in CTEPH patients showed negative correlations with hemoglobin (r = -0.357, P = 0.007) and cardiac index (r = -0.288, P = 0.031), and positive correlations with pulmonary vascular resistance (r = 0.292, P = 0.029) and WHO functional class (r = 0.450, P = 0.001). Moreover, RDW was an independent parameter in the diagnosis of CTEPH (95% confidence interval: 2.866-13.698, P = 0.000); in particular, an RDW level ≥ 13.05% was the most useful cut-off value, with a sensitivity of 82.1% and a specificity of 71.4%.
  
  
  CONCLUSIONS
  Increased RDW level may be an acceptable diagnostic parameter for CTEPH.
authors.affiliation: Department of Physiology, Capital Medical University, Beijing, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Physiology, Capital Medical University, Beijing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.affiliation: Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Capital Medical University, Beijing, China.|Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China.
authors.forename: Yuan-hua
authors.initials: YH
authors.lastname: Yang
authors.affiliation: Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Capital Medical University, Beijing, China.|Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China.
authors.forename: Zhen-guo
authors.initials: ZG
authors.lastname: Zhai
authors.affiliation: Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Capital Medical University, Beijing, China.|Beijing Hospital, Ministry of Health, Beijing, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Physiology, Capital Medical University, Beijing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D002908:Chronic Disease; D004909:Erythrocyte Indices; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D006976:Hypertension, Pulmonary / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000097:blood*; D012189:Retrospective Studies; D014655:Vascular Resistance / Q000502:physiology
chemical_list: D015415:Biomarkers
keywords: chronic thromboembolic pulmonary hypertension; diagnosis; hematological tests; hemodynamics; red cell distribution width