['This study sought to assess predictive values of coronary flow velocity and an index of shear stress throughout the vessel for angiographic restenosis after sirolimus-eluting stent implantation.', 'The study patients underwent successful implantation of a sirolimus-eluting stent for de novo lesions located in native coronary vessels and underwent follow-up angiography 6-9 months later. The TIMI frame count method and quantitative digital angiographic analysis were performed based on the post-stenting angiogram. Coronary flow velocity and Reynolds number, an index of shear stress, were measured.', 'Post-stenting digital angiograms from 267 patients were analyzed. We divided the study patients into two groups: a Restenosis group with 21 patients and a Non-Restenosis group with 246 patients. The Restenosis group indicated significantly lower coronary flow velocity (137.7+/-35.6 mm/sec versus 241.1+/-72.9 mm/sec, p = 0.0001) and lower Reynolds number (107.0+/-35.8 versus 199.2+/-67.1, p = 0.0001) than did the Non-Restenosis group.'] Do low coronary flow velocity and shear stress predict restenosis after sirolimus-eluting stent implantation?