Any study of ST is complicated by the fact that there are multiple risk factors, including patient-, lesion-, and procedure/device-related variables as well as compliance with, or resistance to, antiplatelet agents (5,7- 9,46- 55). Multiple angiographic, procedural, and patient demographic factors associated with BMS thrombosis have been identified (47). Thrombosis after DES deployment has been associated with the presence of renal insufficiency, diabetes, and depressed left ventricular function as well as stent length, bifurcation target stenosis, and stent overlap. Intravascular ultrasound (IVUS) evaluation (51- 52,56) has identified other factors (lower minimum stent cross-sectional area, reduced stent expansion, and residual significant stenosis) related to DES thrombosis. In addition, interruption or discontinuation of dual antiplatelet therapy has been associated with thrombosis of DES, even late after deployment.