Anticoagulation in interventional cardiology : optimizing patient outcome

Thrombotic complications are a common sequel to percutaneous transluminal coronary angioplasty (PTCA), and may present either acutely as abrupt vessel closure, or as late restenosis. Pre-treatment with heparin, in conjunction with aspirin, reduces the incidence of thrombosis although the optimal dose and duration of treatment has still not been established. Continued heparin treatment after PTCA does not reduce the event rate in patients with no angiographic evidence of thrombosis. Low-molecular-weight heparins are more convenient to use than standard heparin and offer theoretical advantages, but these have not yet been demonstrated to affect outcomes. Similarly, there is no evidence that direct thrombin inhibitors improve long-term outcomes, despite their theoretical advantages over heparin. Mixed results have been seen with thrombolytic agents in abrupt vessel closure, but in unstable angina there is conclusive evidence that they are associated with a worse prognosis. Good results have been seen with the glycoprotein IIb/IIIa inhibitors, used in conjunction with aspirin and heparin. Trials of abciximab have shown significantly improved outcomes at 30 days, and encouraging trends have been seen with eptifibatide and tirofiban. Abciximab is the only agent in this class which has been demonstrated to reduce the incidence of late restenosis.