Warfarin remains the only oral anticoagulant option for patients with cardiac valve prostheses, despite its narrow therapeutic index and the availability of newer agents for other indications.
The anticoagulant drug warfarin is a vitamin K antagonist (VKA), coumarin derivative, formed by the racemic mixture of two optically active isomers known by Rectus (R) and Sinister (S) enantiomers in equal proportion, being the S-warfarin five times more potent. Although warfarin is still considered the mainstay of oral anticoagulant treatment, it is a difficult drug to manage due to its narrow therapeutic index. An inappropriate management of patients can lead to subtherapeutic or supratherapeutic levels, increasing the risk of thromboembolic episodes or hemorrhagic episodes, respectively. Common indications for the use of warfarin include stroke prevention in atrial fibrillation, preventing thrombus formation in patients with heart valves and treatment of venous thromboembolism. Unlike situations as nonvalvular atrial fibrillation (and thromboembolic risk factors such as hypertension, diabetes or ventricular dysfunction), venous thrombosis and pulmonary embolism where there is evidence for the use of the new oral anticoagulants (dabigatran, apixaban, rivaroxaban, etc), warfarin and similar remain only option for patients with cardiac valve prosthesis requiring anticoagulation.
André Oliveira Rodrigues (Thu,) conducted a review in Thromboembolic conditions requiring anticoagulation. Warfarin vs. New oral anticoagulants was evaluated. Warfarin remains the only oral anticoagulant option for patients with cardiac valve prostheses, despite its narrow therapeutic index and the availability of newer agents for other indications.