ACE and chronic kidney disease: In nondiabetic patients, those who underwent staged PCI were younger (P = 0.001), had lower prevalence rates of chronic kidney disease (P = 0.013) and Killip class III/IV (P = 0.010), had more three-vessel disease (P < 0.001), nonculprit vessels of left anterior descending coronary artery (P = 0.003), were more frequently to use intra-aortic balloon pump (P = 0.006), angiotensin converting enzyme inhibitor/angiotensin receptor blocker (P < 0.001) during hospitalization, and less likely to receive transradial PCI (P < 0.001) and temporary pacemaker (P = 0.027).