Long-term clinical outcomes after sirolimus-eluting stent implantation for treatment of restenosis within bare-metal versus drug-eluting stents

Background: Sirolimus-eluting stents have been increasingly used for treatment of restenosis after implantation of bare metal stents (BMSs) or drug-eluting stents (DESs), but little is known regarding their long-term outcomes. Methods: We compared long-term clinical outcomes in 295 patients treated with sirolimus-eluting stents for post-BMS (n = 224) vs. post-DES (n = 71) restenosis. All follow-ups were at least 12 months, and the primary endpoint was major adverse cardiac events (MACE), defined as cardiac death, nonfatal myocardial infarction (MI) or target lesion revascularization (TLR). Results: Baseline characteristics were similar between the two groups, except that mean lesion length (28.0 ± 16.2 vs. 19.5 ± 13.6, P < 0.01) and mean stented length (35.4 ± 19.2 vs. 25.7 ± 14.7, P < 0.01) were significantly longer in the post-BMS group. Major in-hospital complications occurred in 2 patients. During a mean follow-up of 31.3 ± 11.1 months, there were 9 deaths (4 cardiac, 5 noncardiac), 3 nonfatal MIs, and 25 TLRs. Late stent thrombosis was documented in 2 patients (1 in each group). There were no between group differences in cardiac or total deaths, but there were trends toward less frequent cardiac death/MI or TLR in the post-BMS group. The cumulative probability of MACE-free survival was significantly better for the post-BMS group (95.0% ± 1.5% vs. 87.3% ± 4.0% at 1 year; 93.0% ± 1.7% vs. 81.0% ± 5.2% at 2 years; Log Rank P = 0.016). In multivariate analysis, post-DES restenosis was the only significant predictor of MACE (OR 3.29, 95%CI 1.13-9.61, P = 0.029). Conclusions: Sirolimus-eluting stents were effective for treatment of in-stent restenosis, but post-DES restenosis was associated with poorer outcomes than post-BMS restenosis.