Sirolimus-eluting stents versus bare-metal stents in patients with in-stent restenosis: results of a pooled analysis of two randomized studies.

Background: Treatment of patients with in-stent restenosis (ISR) remains a challenge. We sought to compare results of sirolimus-eluting stents (SES) with those of bare-metal stents (BMS) in patients with ISR.
Methods: The results obtained in the stent arm of two randomized studies were analyzed. The RIBS I study (450 patients with ISR) allocated 224 patients to BMS; the RIBS II study (150 patients with ISR) allocated 76 patients to SES. Complete 1-year follow-up was obtained in all 300 patients treated with stents.
Results: Although inclusion/exclusion criteria were identical in the two studies, when compared with patients in the BMS group, patients in the SES arm had more adverse baseline characteristics, more diffuse lesions, and smaller vessels. However, late angiographic findings including in-segment recurrent restenosis rate (11 vs. 38%, P < 0.001), minimal lumen diameter (2.52 vs. 1.63 mm, P < 0.001), and late loss (0.13 vs. 1.04 mm, P < 0.001) were significantly better after SES. The 1-year event-free survival was also significantly improved in the SES group (88 vs. 78%, P < 0.05), as the result of a lower requirement for repeated revascularizations (10.5 vs. 19.6%, P < 0.05). Prespecified subgroup analyses were consistent with the main outcome measures. After adjusting for (a) imbalances in baseline characteristics (restenosis OR 0.11 [95% confidence interval (CI) 0.03-0.36]; adverse events hazard ratios (HR) 0.33 [95% CI 0.13-0.84]) and (b) the propensity score (restenosis OR 0.08 [95% CI 0.03-0.28]; adverse events HR 0.24 [95% CI 0.09-0.66]), results of the SES group were superior to those obtained in the BMS group.
Conclusions: When compared with BMS, SES improved the long-term clinical and angiographic outcome of patients with ISR.
(2008 Wiley-Liss, Inc.)