PCI in Specific Patient Populations Several specific patient subsets with higher risks for PCI, and at times higher absolute clinical benefit, have traditionally been underrepresented in RCTs and are described below. The elderly constitute a growing proportion of patients considered for PCI.760 In 1 series examining trends over a 25-year period, the proportion of patients undergoing PCI who were 75 to 84 years of age doubled, and those 85 years of age increased 5-fold.761 Age is one of the strongest predictors of mortality after PCI,762 and elderly patients present with a substantially higher clinical risk profile760 Nonetheless, the angiographic success rates and clinical benefits of PCI in elderly patients are similar to younger patients.763 In fact, the absolute benefit is typically greater because of higher absolute risk of adverse outcomes in these patients.764 However, increased risks of complications such as major bleeding and stroke mandate careful consideration of the benefits and risks of PCI in elderly patients.373 Patients with diabetes represent approximately one third of patients undergoing PCI in the United States. Restenosis, which had been a major limitation of PCI, is significantly reduced in patients with diabetes treated with DES compared with BMS.471 However, there are no definitive data from RCTs supporting different clinical outcomes for different types of DES,765 with a recent meta-analysis of 35 RCTs involving 3852 patients with diabetes unable to find major differences between patients receiving sirolimuseluting stents or paclitaxel-eluting stents.472 Numerous analyses and clini- cal studies have evaluated how the presence of diabetes may impact the clinical outcome of patients undergoing PCI and decisions about PCI or CABG.14,116,163,164,186 These studies and the approach to revascularization decisions in diabetes are addressed in Section 4. Diabetes is an important risk factor for the development of contrast-induced AKI. 