Cyclic coronary flow variation (CCFV), a phenomenon related to repetitive accumulation of platelet aggregates at sites with endothelial injury, was reported to predict the acute ischemic complication after percutaneous coronary intervention. Platelet activation also stimulates neointimal proliferation, which is essential in the late restenosis process. Abciximab, a nonspecific antagonist to the platelet membrane glycoprotein IIb/IIIa as well as other integrins, may eliminate CCFV. A randomized study was conducted to evaluate the effect of abciximab on CCFV and restenosis in morphologically high-risk lesions. Forty-six coronary arteries with objective ischemia on the corresponding vascular territories were successfully treated. The use of abciximab successfully suppressed the occurrence of CCFV (p < or = 0.001) after balloon dilatation. In the follow-up study 3 months later, the use of abciximab predicted a lower loss index and less clinical recurrence (p = 0.008 and 0.03, respectively). The occurrence of CCFV, however, did not affect the angiographic or clinical outcome. The reduction of restenosis and clinical recurrence by the use of abciximab may thus be related to its nonglycoprotein IIb/IIIa effects, in addition to platelet inhibition.