[Dual platelet aggregation inhibition in coronary artery stent implantation--what is evidence-based?]

Dual platelet inhibition (ASA and clopidogrel) is the generally accepted standard therapy to avoid stent thrombosis although clopidogrel is not approved for this indication in Germany. The duration of dual platelet inhibition depends on the complexity of the stenosis, plaque activity and the type of stent implanted. Recent analyses suggested that implantation of drug eluting stents is associated with a substantially higher rate of stent thrombosis when compared with bare metal stents. This in turn fueled an ongoing debate about the optimal duration of dual platelet inhibition after implantation drug eluting stents. Guideline rcommendations vary between between 3 months and lifelong therapy with updates and additional statements published on a monthly basis leaving cardiologists and primary care providers in a state of therapeutic uncertainty. Taking the most recent guidelines and professional statements into account the following duration of dual platelet inhibition can be recommended: dual platelet inhibition for 1 month after implantation of bare metal stents, dual platelet inhibition for 9-12 months after an acute coronary syndrome; dual platelet inhibition for at least 12 months after implantation of drug eluting stents and brachytherapy in patients who are not at high risk for bleeding. Patients with previously implanted drug eluting stents who are currently taking dual antiplatelet therapy are at high risk for developing stent thrombosis when a situation arises that requires cessation or interruption of dual platelet inhibition. Therefore, the interventionalist is advised to carefully discuss risks and benefits of the selected stent and clearly document the decision process in an accepted consent form. When elective or urgent surgery is required the surgeon and practitioner must decide whether the procedure can be performed with reasonable safety without discontinuation of antiplatelet therapy posing a higher bleeding risk to the patient. Patients on chronic oral anticoaglation should be additionally treated with clopidogrel for 1 month after implantation of bare metal or 12 months after drug-eluting stents. Additional treatment with ASS is not generally recommended since the bleeding risk of this triple medication may overweigh the benefits of dual antiplatelet inhibition.