Preventing Restenosis after Implantation of Bare Stents with Oral Rapamycin: A Randomized Angiographic and Intravascular Ultrasound Study with a 5-Year Clinical Follow-Up

Objectives: To establish the efficacy of oral rapamycin at a dose of 2 mg for 1 month at reducing the 6-month restenosis rate after the implantation of bare metal stents. Methods: A prospective, 1: 1 randomized, single-blind, placebo-controlled study was conducted in 108 consecutive patients assigned immediately after stent implantation to oral rapamycin (4 mg loading dose followed by 2 mg daily for 30 days) or a placebo. Results: Rapamycin was maintained in 98% of patients. Angiographic in-stent binary restenosis was 14.3% in the rapamycin group versus 32.1% in the placebo group, with a relative risk (RR) of 0.45 (95% CI 0.24-0.84, p = 0.015). The rapamycin blood concentration at 15 days correlated with binary restenosis (p = 0.044). The volume obstructions found by intravascular ultrasound for the rapamycin and the placebo groups were 18.1 +/- 10.7 and 27.1 +/- 15.7% (p = 0.002), respectively. Major adverse cardiac events at a 5-year follow-up were 31.5% for the rapamycin group and 50.0% for the placebo group (RR 0.63, 95% CI 0.39-1.01, p = 0.078). Conclusions: Oral rapamycin significantly reduces the incidence of restenosis at follow-up compared to a placebo. We believe these findings deserve further testing in larger trials. Copyright (C) 2009 S. Karger AG, Basel