Objective:Although drug-eluting stent(DES) implantation is the primary treatment modality for bare-metal stent(BMS) in-stent restenosis(ISR),little is known about the efficacy and safety profile of DES in the treatment of DES-ISR.The goal of this study was to compare the clinical outcomes following DES treatment for BMS-ISR and DES-ISR.Methods:Rates of major adverse cardiac events(MACE) were compared in 97 consecutive patients who underwent DES implantation for the treatment of ISR(56 BMS-ISR and 41 DES-ISR) from January 2004 to December 2008.Results:Baseline clinical and procedural characteristics were comparable,except that the DES used in the BMS-ISR group was longer and had a larger diameter.The length of follow-up was(28.60±1.96) and(20.34±1.54) months for the BMS-ISR and DES-ISR groups,respectively.One patient(1.8%) experienced non-cardiac mortality and one(1.8%) had target-vessel revascularization(TVR) in the BMS-ISR group.In the DES-ISR group,three patients(7.3%) died of sudden death with a documented acute ST-segment elevation myocardial infarction,and three suffered TVR(7.3%).Kaplan-Meier analysis indicated that cumulative survival probability and MACE-free probability were both significantly lower for the DES-ISR group(log rank test P=0.047 and P=0.005,respectively).In Cox regression analysis,DES-ISR remained an independent predictor for future MACE occurrence after adjustment for other factors(compared with BMS-ISR,risk ratio(RR)=8.743,95% confidence interval(CI) 1.54-49.54,P=0.014).Switching to a different type of DES to treat DES-ISR did not improve the prognosis.Conclusion:DES-ISR patients had a poorer prognosis than BMS-ISR patients after DES therapy. Objective: Although drug-eluting stent (DES) implantation is the primary treatment modality for bare-metal stent (BMS) in-stent restenosis (ISR), little is known about the efficacy and safety profile of DES in the treatment of DES-ISR The goal of this study was to compare the clinical outcomes following DES treatment for BMS-ISR and DES-ISR. Methods: Rates of major adverse cardiac events (MACE) were compared in 97 consecutive patients who underwent DES implantation for the treatment of ISR (56 BMS-ISR and 41 DES-ISR) from January 2004 to December 2008. Results: Baseline clinical and procedural characteristics were comparable, except that the DES used in the BMS-ISR group was longer and had a larger diameter. The length of follow-up was (28.60 ± 1.96) and (20.34 ± 1.54) months for the BMS-ISR and DES-ISR groups, respectively. One patient (1.8%) experienced non-cardiac mortality and one revascularization (TVR) in the BMS-ISR group. the DES-ISR group, three patients (7.3%) died of sudd en death with a documented acute ST-segment elevation myocardial infarction, and three suffered TVR (7.3%). Kaplan-Meier analysis indicated that cumulative survival probability and MACE-free probability were both significantly lower for the DES-ISR group P = 0.047 and P = 0.005, respectively). In Cox regression analysis, DES-ISR remained an independent predictor for future MACE occurrence after adjustment for other factors (compared with BMS-ISR, risk ratio (RR) = 8.743, 95% confidence interval (CI) 1.54-49.54, P = 0.014). Switching to a different type of DES to treat DES-ISR did not improve the prognosis. Conlusion: DES-ISR patients had a poorer prognosis than BMS-ISR patients after DES therapy.