Bleeding events in pulmonary arterial hypertension

Area of Science:

• Cardiology
• Pulmonology
• Pharmacology

Background:

• Pulmonary arterial hypertension (PAH) is characterized by vasoconstriction, proliferation, inflammation, and thrombosis.
• Anticoagulant drugs, specifically vitamin K antagonists (VKA), are commonly prescribed for PAH patients.
• Current guidelines recommend VKA despite a lack of robust clinical trial evidence or formal regulatory approval for PAH.

Purpose of the Study:

• To review the current use of VKA in PAH management.
• To highlight the paradoxical risks of thrombosis and bleeding associated with VKA in PAH.
• To discuss drug interactions and safety monitoring for VKA in PAH patients.

Main Methods:

• Literature review of existing studies and guidelines on VKA use in PAH.
• Analysis of pathophysiological mechanisms in PAH relevant to anticoagulation.
• Examination of bleeding and thrombotic risks in specific PAH subpopulations.
• Review of drug interactions with VKA in PAH patients.

Main Results:

• VKA are widely used in PAH background therapy, but evidence from randomized controlled trials is limited.
• PAH involves thrombosis, yet patients have an increased risk of bleeding events, particularly those with connective tissue diseases, congenital heart disease, or chronic thromboembolic pulmonary hypertension.
• Concomitant use of prostanoids, sildenafil, or sitaxentan with VKA requires caution and dose adjustment.

Conclusions:

• VKA use in PAH presents a therapeutic challenge due to the dual risk of thrombosis and bleeding.
• Close monitoring of International Normalized Ratio (INR) is essential for patient safety.
• Further research is needed to establish the definitive role and optimal use of anticoagulation in PAH.