Chronic thromboembolic pulmonary hypertension (CTEPH) and coagulation defects: Before and after treatment

Background: Although CTEPH is a thromboembolic disorder, the effect of the coagulation process in the pathogenesis and progression of the disease has not been fully elucidated. Aims: To assess coagulation in CTEPH and to evaluate differences after the initiation of PH-specific treatment. Methods: We studied 20 CTEPH patients (not on anticoagulation therapy at the time of tests) and 20 controls. CTEPH patients were reevaluated 1 year after therapy initiation. We performed Platelet- Function Analyzer/PFA-100 testing, ADP and epinephrine/EPI induced Light Transmission Aggregometry/LTA, Thrombelastometry/ROTEM (na-TEM) and Endogenous Thrombin Potential/ETP essay. Results: Before treatment and when compared to controls, CTEPH patients presented prolonged PFA-100 closure times (174.8sec±27.3, p=0.003), lower EPI and ADP-LTA (43.9%±11.2, p Conclusions: Our data suggest that the observed coagulation defects in CTEPH persist even after PH treatment initiation. EPI-LTA was the only index displaying significant increase after treatment.