Altered hemostasis in pulmonary hypertension

Area of Science:

• Cardiovascular Medicine
• Hematology
• Pulmonary Medicine

Background:

• Pulmonary hypertension (PH) is a condition marked by elevated pulmonary artery pressure.
• PH is associated with vascular remodeling and in-situ thrombosis.
• Elevated shear stress and inflammation in PH may promote a pro-thrombotic state.

Purpose of the Study:

• To review the evidence linking coagulation system alterations to pulmonary hypertension.
• To explore the role of thrombosis in the pathogenesis and progression of PH.

Main Methods:

• Review of in-vitro, animal, and human studies on coagulation in PH.
• Analysis of histopathology and biochemical markers related to thrombosis and fibrinolysis.

Main Results:

• In vitro data suggest elevated shear stress and inflammation enhance platelet activation and pro-coagulant factor expression.
• Human and animal studies confirm increased platelet activation, decreased platelet survival, and altered levels of von Willebrand factor and thrombomodulin in PH.
• Evidence indicates a net loss of fibrinolytic activity, with increased plasminogen activator inhibitor-1, contributing to thrombosis in PH.

Conclusions:

• Coagulation system abnormalities, including platelet activation and impaired fibrinolysis, are evident in pulmonary hypertension.
• These hemostatic changes may contribute to in-situ thrombosis, a common finding in PH.
• While anticoagulation shows survival benefits, the direct causal link between coagulation and PH development/persistence requires further investigation.