Dual antiplatelet therapy has become the cornerstone of the treatment of patients undergoing coronary stenting and of those with acute coronary syndromes with or without stent implantation.
Although there is consensus about the indication for dual antiplatelet therapy, little evidence exists about the optimal duration of therapy.
In patients surviving non–ST-segment–elevation acute coronary syndromes, 1 year of treatment is advised.
Intuitively, cardiologists prefer longer dual antiplatelet therapy rather than single antiplatelet medication ( Acetylsalicylic acid [ Aspirin ] alone ) in patients with drug-eluting stents compared with bare metal stents. Consequently, many stented patients are on dual antiplatelet therapy, mainly Aspirin and Clopidogrel ( Plavix ).
The only important side effect of dual antiplatelet therapy is increased bleeding compared with Aspirin alone. This has been found in the large Clopidogrel trials in acute coronary syndromes and in atrial fibrillation.
Dual antiplatelet therapy has been shown to be as hazardous as oral anticoagulation with Warfarin.
Special attention has been given to the risks of dual antiplatelet therapy in patients awaiting coronary artery bypass surgery. Taking Clopidogrel with Aspirin has been associated with significantly increased blood loss during coronary surgery compared with aspirin alone.
However, this excess bleeding was not associated with an increased risk of reoperation or mortality. Yet, it is generally advised that patients discontinue Clopidogrel 5 days before coronary surgery.
Little is known, however, about the optimal strategy in patients on dual antiplatelet therapy undergoing other forms of surgery.
However, the most vexing problem in this field is the use of dual antiplatelet therapy in patients on oral anticoagulation for long-term stroke prevention in atrial fibrillation. When dual antiplatelet therapy was combined with Warfarin, bleeding increased by 50% in the Randomized Evaluation of Long-Term Anticoagulant Therapy ( RE-LY ) trial and 100% to 400% in a large Danish registry. ( Xagena )
Verheugt FWA, Circulation 2013; 128: 2058-2061