[Platelet inhibition in clinical practice]

Evidence for a beneficial effect of antiaggregatory treatment is strong for many clinical entities. However, there are controversial situations challenging us in daily practice, such as failure of antiaggregatory therapy (case 1), inconclusive evidence for the benefit of certain antiaggregatory medications (case 2) or increased risk of bleeding in aorto-coronary bypass surgery after irreversible antiaggregation (case 3). The phenomenon of aspirin or clopidogrel resistance means the occurrence of ischemic complications despite adequate antiaggregation. It may be caused by malcompliance, variable bioavailability, drug interactions or genetic polymorphisms. For peripheral arterial occlusive disease, a beneficial effect of aspirin is questioned by recent studies in contrast to the recommendations given in international guidelines. Finally, irreversible inhibition of platelet aggregation by GPIIb/IIIa inhibitors given during percutaneous coronary intervention can be overcome by transfusion of functional platelets to reduce bleeding during subsequent bypass surgery. Further studies will help to improve the management of antiaggregatory therapy in such challenging clinical situations.