Optimizing long-term dual aspirin/clopidogrel therapy in acute coronary syndromes: When does the risk outweigh the benefit?

Most guidelines recommend indefinite use of aspirin in patients at increased atherothrombotic risk. Dual antiplatelet therapy (aspirin/clopidogrel) is significantly more effective than aspirin monotherapy in reducing cardiovascular risk in a number of patient populations. As a result, dual therapy is recommended in many patient groups, including those with acute coronary syndromes and those who have undergone percutaneous coronary intervention. The recommended duration of clopidogrel/aspirin treatment is generally less than one year and, in some cases, as little as one month. However, there is evidence from a range of patient populations that more prolonged clopidogrel/aspirin therapy may be more effective than short-term treatment in reducing cardiovascular risk in some patients. The effects of discontinuing clopidogrel after an event-free period of one year require examination in clinical trials. Trial data are also needed to guide management of patients in whom early antiplatelet withdrawal is being considered (e.g. those who require non-cardiac surgery). This review discusses the benefits and risks of long-term dual antiplatelet therapy in a range of clinical situations.