Efficacy and safety of drug-eluting stent implantation for the treatment of in-stent restenosis occurring within bare-metal stent and drug-eluting stent

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.