Do Drug-Eluting Stents Cause Late Stent Thrombosis?

摘要

Since the introduction of balloon angioplasty, restenosis has become the "Achillis tendon" of this mode of percutaneous coronary intervention (PCI). Stent implantation improves but does not eliminate restenosis. However, an iatrogenic disease, namely instent restenosis (ISR), emerges following placement of first-generation bare metal stents (BMS) and may be even more difficult to treat than the parent disease. Over the last few years, multiple randomised clinical trials have demonstrated the efficacy of drug-eluting stents (DES) to substantially reduce angiographic ISR and the clinical need for repeat revascularisation when compared with BMS. Moreover, these studies showed no short-term safety concerns, particularly the issue of stent thrombosis. The encouraging initial data led to subsequent widespread adoption of DES in interventional cardiology with utilisation of DES from 50% to >90% of all stent implantation. A recent meta-analysis of randomised controlled trials comparing sirolimus and derivatives or paclitaxel and derivatives eluting stents versus BMS with up to 12 months' follow up demonstrated a significant reduction of major adverse cardiac events (MACE; a composite of death, myocardial infarction [MI], and revascularisation) from 19.9% to 10.1% (odds ratio [OR] 0.46; 95% confidence intervals [CI] 0.41 to 0.52, p<0.001). The benefit isdriven by reduction in revascularisation while rates of death and MI were not different between the two groups. Importantly, the occurrence of stent thrombosis was 0.7% with DES versus 0.8% with BMS (OR 0.71; 95% CI 0.41 to 1.25, p=0.24) at 1 year.