Background and Objectives:Increased carotid intima-media thickness (IMT) is known to be associated with adverse cardiovascular events in the patients with risk factors or established atherosclerosis. However, the prognostic importance of carotid IMT is uncertain in the patients who underwent percutaneous coronary intervention (PCI). We sought to evaluate the association of carotid IMT with major adverse cardiovascular events (MACE) and restenosis in the patients who underwent PCI. Subjects and Methods:The study population consisted of 308 consecutive patients who underwent PCI, and they were followed up for mean of 30.6±13.3 months. Base on the median values of carotid IMT, which was measured in the right common carotid artery at the time of PCI with using high-resolution ultrasound and a semiautomatic method, the subjects were divided into the thick (n=156, 1.003±0.14 mm) and thin IMT (n=152, 0.748±0.07 mm) groups, and they were followed up for at least 1 year. Results:Patients with thick carotid IMT were older (61±9 years vs. 57±10 years, respectively, p=0.001), had a higher body mass index (25.0±3.0 vs. 23.9±4.0, respectively, p=0.017), a history of previous myocardial infarction (20% vs. 9%, respectively, p=0.008), more multivessel disease and more restenosis (34.6% vs. 23.0%, respectively, p=0.025) than those patients with a thin carotid IMT. However other MACEs such as death, myocardial infarction, stroke, heart failure and target lesion revascularization did not show any significant differences between the two groups. Multivariate Cox regression analysis showed that carotid IMT was an independent predictor of restenosis (odds ratio: 1.754, 95% confidence interval: 1.1296 to 2.726, p=0.012). Conclusion:An increased carotid IMT is associated with restenosis, but it does not have clinical prognostic importance for the patients who underwent PCI during a mean follow up period of 31 months. (Korean Circulation J 2007;37:103-107)