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Abstract
- 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.
- We examined the available literature
on the efficacy and adverse effects of
drug-eluting stents, based on the standard
Prescrire methodology.
- 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 mortality, cardiac mortality,
the risk of myocardial infarction, or
stent thrombosis. Few follow-up data
are available beyond 4 years.
- Revascularisation of the treated
coronary artery was about half as frequent
with drug-eluting stents as with
bare metal stents. However, this 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
revascularisation. Sirolimus-eluting
stents appear to be slightly more
effective than paclitaxel-eluting stents
in terms of the revascularisation rate.
- 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.