Clinical Medicine Reviews in Vascular Health

Sirolimus was isolated in 1975 and was initially approved for the treatment of renal transplant rejection. The main mechanism of action is mTOR inhibition, which prevents cell cycle progression. The first-in-human study of the sirolimus-eluting stent (SES) was initiated in 1999 in Sao Paulo Brazil and Rotterdam. The study demonstrated a reduction in restenosis after SES implantation when compared with bare-metal stents. The first approved drug-eluting stent was the SES Cypher®. Several modifications in stent platform and polymer coating have been made, in an effort to improve deliverability and to reduce inflammatory response secondary to nonbiocompatible polymers. Bioabsorbable polymer and polymer-free technologies are the main characteristic of the second- and third-generation SES. Larger studies with longer follow-up are needed to prove the efficacy of those stents when compared with previous platforms.