Drug-eluting coronary stents: many meta-analyses, little benefit

(1) Angioplasty is one method of unblocking a stenosed coronary artery. A metal stent is sometimes placed in the vessel lumen. Drug-eluting stents coated with an immunosuppressant or cytotoxic drug have been developed with the objective of reducing the risk of recurrent stenosis; (2) We examined the available literature on the efficacy and adverse effects of drug-eluting stents, based on the standard Prescrire methodology; (3) We found a plethora of clinical trials of drug-eluting stents, and numerous meta-analyses, reflecting the broad economic implications of the market for these devices. Yet drug-eluting stents appear to be no more effective than bare metal stents in reducing overall morality, cardiac mortality, the risk of myocardial infarction, or stent thrombosis. Few follow-up data are available beyond 4 years; (4) Revascularisation of the treated coronary artery was about half as frequent with drug-eluting stents as with bare metal stents. However, the apparent advantage is difficult to quantify because in some trials the decision to re-operate was based solely on angiographic criteria, leading to more frequent revascularization. Sirolimus-eluting stents appear to be slightly more effective than paclitaxel-eluting stents in terms of the revascularisation rate; (5) In contrast, late thrombosis (more than a year after stent placement) seems to be more frequent with drug-eluting stents than with bare metal stents. This risk can be reduced by long-term antiplatelet treatment (with clopidogrel plus aspirin), but the benefit is offset by the accompanying increased risk of severe haemorrhagic events. Serious allergic reactions have also been reported; (6) In most cases, especially when the risk of restenosis is low or moderate, it is better to use a bare metal stent. Coronary artery bypass grafting should be considered when there is a high risk of restenosis. Drug-eluting stents are just one alternative to surgery.