NEW ASPECTS OF ANTITHROMBOTIC THERAPY DUR ING PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY (PTCA)

Percutaneous transluminal coronary angioplasty (PTCA) is increasingly extended to patients with complex stenosis morphology or acute coronar y insufficiency syndromes. Especially these patients are at high risk to suffer thrombotic complications during PTCA. Thus an effective anti coagulant regimen is of great importance during PTCA. PTCA-induced dam age of the arterial wall induces the formation of a platelet-rich thro mbus. After adhesion of platelets to the arterial wall further platele t aggregation is stimulated mainly by activated thrombin, followed by fibrin formation stabilizing the growing thrombus. This article descri bes the pathophysiologic basis of coagulation and thrombus formation d uring PTCA and potential targets for a therapeutic intervention. The r esults of clinical studies regarding the currently available antithrom botic, antiplatelet, and thrombolytic therapies are described. Further more, the results are reported of clinical studies of newer anticoagul ant strategies such as inhibition of the platelet glycoprotein recepto r GP IIb/IIIa with monoclonal antibodies and direct inhibition of acti vated thrombin with hirudin analogues. At present an aggressive antico agulant regimen with heparin is recommended during the PTCA procedure. Heparin should not be continued after the intervention unless a compl ication during the procedure has occurred. Already before PTCA patient s should receive 100 mg aspirin daily. Thrombolytic therapy during PTC A has failed to demonstrate an improvement of clinical results. Thus i ts use should be limited to bail-out situations. First results with hi rudin analogues and GP IIb/IIIa receptor antagonists are promising. Fu rther studies are, however, warranted before a general use can be reco mmended.