Dual antiplatelet therapy and drug eluting stents: a marriage of convenience

Despite the "elastic recoil" of the artery was abrogated with the stent deployment, there was still a non-depreciable rate of in-stent restenosis due to the neointimal proliferation inside the stents. In an attempt to fight the exaggerated proliferation after coronary stent implantation, our lab first used rapamycin in an animal model of restenosis showing the effectiveness of this antiproliferative drug in preventing this neointimal proliferation. [3] Soon after, stents locally delivering antiproliferative drugs (the so called drug eluting stents [DES]) were designed and tested in humans with impressive results in terms of in-stent restenosis inhibition. Two drug-eluting stents (DES), the Cypher stent (Cordis/Johnson & Johnson) and Taxus stent (Boston Scientific), were introduced. The Cypher and Taxus stents are produced by coating a stainless-steel stent with a thin layer of a non-erodable synthetic polymer containing either sirolimus or paclitaxel respectively. DES implantation resulted in a rate of restenosis below 10% (compared to 30% observed after bare metal stents implantation) [4-6], with a similar rate of in-stent thrombosis. [7,8] It is important to remind that dual antiplatelet therapy was mandatory for at least 3–6 months after DES implantation. However some initial warns were raised by few groups suggesting that DES do not undergo a complete re-endothelization. [9,10] It was just a matter of time to face, with striking surprise, the unexpected high rate of late (>30 days after stent deployment) and especially very late in-stent thrombosis (beyond 12 months from stent implantation) in DES compared to bare metal stents. [11,12] Further cause for concern came from the Basel Stent Cost-effectiveness Trial-Late Thrombotic Events (BASKET-LATE) data, which showed that among 746 DES or BMS patients who had dual antiplatelet therapy discontinued after the first six months, the rate of cardiac death or non-fatal MI over the following year was higher in patients