Red cell distribution width is increased in chronic thromboembolic pulmonary hypertension

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 B eijing C hao‐ Y ang H ospital. 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 W orld H ealth O rganization ( 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%. Conclusion Increased RDW level may be an acceptable diagnostic parameter for CTEPH .