Sirolimus-eluting stents: A small piece of the story of percutaneous coronary intervention

Since the first percutaneous coronary intervention (PCI) was performed by Andreas Gruntzig in 1977, 1 the procedure has evolved greatly to become the dominant revascularization technique for obstructive coronary artery disease.The use of stents, introduced in 1986, improved the success and safety of balloon angioplasty and the addition of an antiproliferative agent to the metal struts (drug-eluting stents or DES), via a polymer coating, significantly reduced restenosis.2 The downside of their antiproliferative effect was the increased risk of late stent thrombosis associated with impaired re-endothelization.3 First-generation DES using sirolimus or paclitaxel were first introduced in 2002.Sirolimus, also known as rapamycin, is an immunosuppressive agent that arrests the cell cycle in the G1/S phase and inhibits proliferation and migration of vascular smooth muscle cells (VSMCs).3 Paclitaxel is an antineoplastic agent that inhibits microtubules and hence proliferation and migration of VSMCs.The increased risk of stent thrombosis reported in several studies for these DES, even mitigated by improvements in procedure-related factors (stent malapposition and/or underexpansion) and enhanced stent design, led to the development of second-generation DES, which were covered with less potent antiproliferative agents (everolimus, zotarolimus and biolimus) in conjunction with new platforms and polymers.3 Newer-generation DES showed lower rates