[Platelet function: new drugs, new assays : possible impacts on operative medicine?]

Dual antiplatelet therapy with aspirin and a P2Y12 receptor blocker is a well-established strategy to prevent thrombotic complications in patients with acute coronary syndromes (ACS) and after percutaneous coronary interventions (PCI). Current practice guidelines for antiplatelet therapy advocate a 1 to 12-month dual antiplatelet therapy after bare metal stent PCI and an up to 12-month dual antiplatelet therapy after PCI in patients with ACS and drug-eluting stent PCI. Premature withdrawal of dual antiplatelet therapy carries a substantial risk of stent thrombosis but perioperative continuation of dual antiplatelet therapy is associated with an increased risk of bleeding, particularly in patients treated with the new potent drugs prasugrel and ticagrelor. Based on the various available assays, the lack of validated cut-offs and the disappointing results of targeted antiplatelet therapy as demonstrated by the GRAVITAS trial, current guidelines of international societies recommend platelet function testing only for selected high risk patients despite the known association between clopidogrel low responsiveness and ischemic events. However, for individual patients taking clopidogrel, platelet function monitoring may be considered to safely shorten the preoperative waiting period, to assess the risk of bleeding and transfusion and to initiate specific therapy in bleeding patients.