Lifelong anticoagulation is necessary for the prevention of stroke in patients with rhythm disturbances and with mechanical valves. Patients who have a coronary stent implanted also need the antiplatelet drugs aspirin and clopidogrel to prevent the rare but lethal complication of stent thrombosis. For patients taking oral anticoagulant drugs (for atrial fibrillation or mechanical valve) who also have to undergo coronary stenting, the optimal antithrombotic treatment is still unknown, even though the use of all three drugs (oral anticoagulants, aspirin and clopidogrel) seems logical for the prevention of stroke and stent thrombosis. However, treatment with all three drugs often causes serious bleeding complications and the frequent need to discontinue the aspirin and clopidogrel.
Now, results from the WOEST study (What is the Optimal antiplatElet and anticoagulant therapy in patients with oral anticoagulation and coronary StenTing) show that a strategy of adding clopidogrel only to anticoagulants (and omitting aspirin) causes less bleeding and is safe with respect to preventing thrombotic and thromboembolic complications such as stent thrombosis. The results were presented here today at ESC Congress 2012 by Dr Willem Dewilde, TweeSteden Hospital, Tilburg, the Netherlands, who said that "WOEST is the first study demonstrating that the omission of aspirin in patients treated with oral anticoagulants and having a coronary stent is safe".
He explained that the WOEST study was designed to resolve this specific dilemma of cardiology - the optimal antithrombotic treatment for patients taking oral anticoagulant drugs who also have to undergo coronary stenting. The study hypothesis was that aspirin could be omitted. "This would possibly lead to less bleedings," said Dr Dewilde, "but hopefully would not increase the risk of thrombotic complications such as stent thrombosis."