Platelets and restenosis

Restenosis is currently the major limitation of percutaneous transluminal c oronary angioplasty (PTCA). Factors such as elastic recoil, migration of va scular smooth muscle cells from media to intima, neointimal proliferation a nd vascular remodeling underly the restenotic process. Presently there is n o effective therapy available for restenosis. The role of platelets in the development of thrombosis and abrupt closure after PTCA is well recognized. However, the effects of platelets in PTCA extend well beyond the early pha se. Although antiplatelet agents such as glycoprotein IIb/IIIa antagonists have been reported to reduce target vessel revascularization, major unresol ved controversies still exist. This report reviews the potential role of pl atelets in restenosis. Various drugs, successfully tested in experimental s tudies and in a small number of human studies, that inhibit the effect of p latelets on the restenotic process are also reviewed. (C) 2000 by the Ameri can College of Cardiology.