The Dynamic Registry was extended through June 2007 to a) continue annual patient follow-up from 3 to 5 years for the 2020 Wave 2 Registry patients who underwent PCI in 1999 (characterized by frequent stent use of varying types); b) perform one-year follow-up on the 2124 Wave 3 Registry patients, and annual follow-up to 5 years on the approximately 150 Wave 3 patients who underwent PCI in 2001/2002 and received the then novel intracoronary radiation therapy; c) enroll and follow annually for 4 years a Wave 4 of 2000 Registry patients who will undergo PCI following the introduction of the much awaited drug-eluting stents into clinical practice; d) enroll and follow for at least one year a Wave 5 of 2000 Registry patients who will undergo PCI at a time when subsequent generations of drug-eluting stents have penetrated clinical practice. As successfully accomplished with all previous waves of patient enrollment, women and minorities will continue to be oversampled in the Registry, as an important study aim is to investigate potential health disparities in clinical practice and outcome by gender, and race/ethnicity, while controlling for socioeconomic status. Finally, the investigators will coordinate a cost effectiveness analysis on the use of drug-eluting stents in a same of Wave 4 registry patients supported through a separate source of funding, and pilot test new data collection forms in the setting of peripheral arterial disease catheter-based interventions.