WASHINGTON, DC – The IMPROVE (IMPact on Revascularization Outcomes of intraVascular ultrasound-guided treatment of complex lesions and Economic impact) trial will randomize 3,100 patients at up to 100 centers in North America and Europe who are candidates for percutaneous coronary intervention (PCI) of complex lesions to undergo guidance by intravascular ultrasound (IVUS) or by conventional angiography. Complex lesions will include severe calcification, bifurcations, in-stent restenosis, chronic total occlusions, Type C, and long lesions.