Background and Objectives) Incidental, asymptomatic non-target lesions have been treated conservatively, because prophylactic percutaneous coronary intervention (PCI) for such minimal or intermediate lesions showed similar restenosis rates to those of PCI for symptom-causing lesions, but the clinical introduction of drug-eluting stents(DES), it is now being considered for PCI to prevent plaque instability. However, the impact of incidental stenoses on future cardiac events remains unknown. The aim of this study was to assess the incidence and risk factors of rapidly progressive non-target lesions revascularization after successful implantation of DES. Methods and Results) We performed a retrospective cohort study to determine the rate and features of clinical plaque progression in patients undergoing PCI with DES from June 2003 through June 2005 using the Catholic University PCI registry data from multiple centers. Clinical and angiographic data were obtained from 325 patients with a mean follow-up of 11 months ; among 51(15 %) patients showed plaque progression of non-target lesions. 28 (54.9%) were received medical treatment and 23 (45.1%) required additional non-target lesion revascularization. After multivariate analysis, the independent predictors of progressive non-target lesions revascularization were hsCRP and multivessel disease. Patients with three-vessel disease at initial PCI were more likely to require PCI again rather than medical treatment compared to one or two-vessel disease (adjusted odds ratio, 6.48 [p<0.004] for more than 2 vessels; adjusted odds ratio, 17.35 [P<0.003] for 3 vessels). It was shown that the majority of lesions requiring subsequent PCI were located in proximal portion of target lesion (39% v/s distal 8%) and non-target vessel (52%). Elevated CRP level were strong independent predictor (adjusted odds ratio, 6.33 : p< 0.007). Conclusions) Elevated CRP levels and multivessel coronary artery disease at the time of initial PCI were independent predictor of rapidly progressive non-target lesions. Location of Non-TLR requiring PCI compared with original PCI site

Progression artery Original PCI in different artery(12) Original PCI in same artery(11) Proximal from initial site  Distal from initial site LAD(10) 6 3 1 LCX(3) 1 3 0 RCA(7) 3 3 1 Lt. Main(1) 2 0 0