vitamin-k-semiquinone-radical and thienopyridine

Dual antiplatelet treatment of aspirin and a thienopyridine (either ticlopidine or clopidogrel) is the standard of care in patients undergoing coronary artery stenting (PCI-S). Such treatment however, is not generally applicable in patients with concomitant indication for vitamin K antagonists (VKA), in whom therefore the optimal treatment is currently undefined. According to the limited available evidence, the management of these patients is substantially variable, but triple therapy of VKA, aspirin and a thienopyridine is the most frequently adopted. Both VKA and dual antiplatelet treatment in fact are warranted to actually prevent systemic thromboembolism and stent thrombosis, although an increased haemorrhagic risk might be associated with such therapy. A substantial incidence of bleeding has been effectively observed with triple therapy in a few, small, retrospective, observational series. The risk of haemorrhage appears to increase with the duration of treatment, although concomitant factors (i.e., advanced age, presence of gastrointestinal lesions, excessive anticoagulation or traumatic manoeuvres), rather than the administration of numerous antithrombotic agents in itself, may play a role. As expected, no thromboembolic or thrombotic events have been generally reported with such treatment. Because of the limited and poor quality data currently available on the management of patients with an indication for VKA undergoing PCI-S, large-scale registries and clinical trials are warranted to determine the optimal antithrombotic treatment in this patient subset, which is foreseen to progressively increase over the next years.

Topics: Angioplasty, Balloon, Coronary; Anticoagulants; Aspirin; Drug Therapy, Combination; Humans; Platelet Aggregation Inhibitors; Pyridines; Stents; Vitamin K; Warfarin