Anticoagulation Following Coronary Stenting
Anticoagulation Following Coronary Stenting
What is the optimal therapeutic regimen after percutaneous coronary intervention with a stent (Cypher) in a patient using warfarin for recent pulmonary embolism? Should both aspirin and clopidogrel be used along with warfarin?
Coronary stent implantation is the predominant method of percutaneous coronary interventions. The chief limitation of coronary stenting is still in-stent restenosis, with an estimated rate of 17% to 32%. Drug-eluting stents, such as the sirolimus stent or Cypher stent, have been shown to reduce the incidence of in-stent restenosis by preventing cellular proliferation. However, the metallic surface can stimulate thrombosis before it becomes entirely covered with endothelial tissue (a process that may take several weeks). Furthermore, the manufacturer reports that some in vitro laboratory experiments have shown that sirolimus potentiates the effect of some platelet agonists and, thus, may promote thrombus formation.
In patients at risk for cardiovascular disease, aspirin may reduce both cardiovascular deaths and total cardiovascular events. It may exert its beneficial effect not only by acting on platelets, but also by other mechanisms, such as preventing thromboxane A2 (TXA2)-induced vasoconstriction or reducing inflammation. Furthermore, low-dose aspirin may suppress vascular inflammation and thereby increase the stability of atherosclerotic plaque. However, aspirin alone does offer optimal antiplatelet effect in the setting of stenting, and thus clopidogrel is advised. Clopidogrel should be used for 3-6 months, together with aspirin after which it can be stopped. As warfarin has no effect on platelet and endothelial function, it does not offer optimal anticoagulation in this specific setting, although in the patient in question it is required for prophylactic therapy for pulmonary embolism. Notwithstanding the fact that there are few data at this stage, cardiologists at our center advocate the use of aspirin, clopidogrel, and warfarin in the setting outlined in your question. The risk of hemorrhage may be increased and, therefore, the benefit of such anticoagulation must be weighed against the catastrophic risk of acute stent thrombosis.
What is the optimal therapeutic regimen after percutaneous coronary intervention with a stent (Cypher) in a patient using warfarin for recent pulmonary embolism? Should both aspirin and clopidogrel be used along with warfarin?
Coronary stent implantation is the predominant method of percutaneous coronary interventions. The chief limitation of coronary stenting is still in-stent restenosis, with an estimated rate of 17% to 32%. Drug-eluting stents, such as the sirolimus stent or Cypher stent, have been shown to reduce the incidence of in-stent restenosis by preventing cellular proliferation. However, the metallic surface can stimulate thrombosis before it becomes entirely covered with endothelial tissue (a process that may take several weeks). Furthermore, the manufacturer reports that some in vitro laboratory experiments have shown that sirolimus potentiates the effect of some platelet agonists and, thus, may promote thrombus formation.
In patients at risk for cardiovascular disease, aspirin may reduce both cardiovascular deaths and total cardiovascular events. It may exert its beneficial effect not only by acting on platelets, but also by other mechanisms, such as preventing thromboxane A2 (TXA2)-induced vasoconstriction or reducing inflammation. Furthermore, low-dose aspirin may suppress vascular inflammation and thereby increase the stability of atherosclerotic plaque. However, aspirin alone does offer optimal antiplatelet effect in the setting of stenting, and thus clopidogrel is advised. Clopidogrel should be used for 3-6 months, together with aspirin after which it can be stopped. As warfarin has no effect on platelet and endothelial function, it does not offer optimal anticoagulation in this specific setting, although in the patient in question it is required for prophylactic therapy for pulmonary embolism. Notwithstanding the fact that there are few data at this stage, cardiologists at our center advocate the use of aspirin, clopidogrel, and warfarin in the setting outlined in your question. The risk of hemorrhage may be increased and, therefore, the benefit of such anticoagulation must be weighed against the catastrophic risk of acute stent thrombosis.