NATIONAL INSTITUTE FOR CLINICAL EXCELLENCE
Health Technology Appraisal
Review of coronary artery stents and appraisal of drug eluting stents
Scope
Objective: To assess the clinical effectiveness and cost effectiveness
of coronary artery stents and drug eluting stents, for the primary prevention
of restenosis following percutaneous coronary interventions (PCI), and to provide
guidance to the NHS in England and Wales 1.
Background: The Institute issued guidance on the use of coronary artery
stents in May 2000 (Technology appraisal guidance no.4). The date set for review
of this guidance was April 2003, the point at which the Institute's Guidance
Executive will consider an update to the original assessment report, together
with comments on it from consultees. The review date was set on the basis of
the Institute's judgement of the pace of change in the evidence base at the
time the original guidance was issued. The original guidance will remain in
place unless and until any new guidance has been issued. The review will consider
whether any new evidence that has become available justifies a change to the
original guidance.
Technology: Audit data from the British Cardiac Interventional Society
indicates that during 2000, 85% of PCIs involved the use of a stent. In addition
to the 'conventional' stents appraised during 2000, there have been recent developments
in drug eluting stents, which are coated in a drug which is released over time
(eluted), with the intention of slowing down the processes of restenosis. Current
drugs used include sirolimus and paclitaxel.
| Interventions |
The use of stents and drug-eluting stents as an adjunct to PCI for the
primary prevention of restenosis. The use of stents for in-stent restenosis
will not be included in the appraisal.
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| Population |
Patients with coronary heart disease requiring revascularisation.
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| Current standard treatments (comparators) |
Given that the present guidance advises that:
- For patients with either stable or unstable angina, or acute myocardial
infarction (MI), and where percutaneous coronary interventions (PCI) is
the clinical appropriate procedure, stents should be used routinely.
- Where
it is considered clinically appropriate to undertake either PCI or coronary
artery bypass grafting (CABG), the availability of stents should push
the balance of clinical decision making towards PCI.
- Arteries with a diameter of less than 2.5mm and greater than 3.5mm should
only normally be stented in the setting of a so-called 'bail out' procedure
(i.e. when acute closure of the vessel occurs following PCI) or if there
has been a sub-optimal result following ballooning alone or as part of
properly conducted trials. These criteria do not apply to saphenous vein
grafts (SVG). The Institute is aware that new evidence on stenting in
arteries with diameter less than 2.5mm is likely to become available soon.
If necessary, this guidance will be amended to take account of the fully
reported results.
- This guidance specifically relates to the present clinical indications
for PCI and excludes conditions (such as many cases of stable angina)
which are currently adequately managed with standard drug therapy.
The following comparisons will therefore be made:
'Conventional' stents
- New evidence on conventional stenting, including the extension of stenting
to small vessels and long lesions, compared to either PCI without stenting
or CABG.
Drug-eluting stents
- Drug-eluting stents will be compared with the current recommended
conventional stent interventions detailed in the current guidance or
CABG.
- Evaluation of drug-eluting stents compared with conventional stenting
should also relate to lesion type (A, B1, B2, C), lesion length and
vessel diameter.
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| Other considerations |
Other issues requiring consideration:
- The comparator for the 2000 guidance was PCI without stent. For this
appraisal, some on-going studies compare drug-coated stents with CABG,
and ideally, we would also wish to make this comparison, where appropriate.
This will depend on the state of the evidence base. Other relevant comparisons
are those of conventional, drug-drug-eluting stents for the primary prevention
of stenosis in PCI against the technique that would otherwise have been
chosen.
- Quality of life will be an important outcome. In addition, NICE will
be particularly interested in longer term outcomes such as revascularisations,
MIs averted and length of life.
- Patient preferences for different interventions.
- The role of concurrent therapies (e.g. antiplatelets or anticoagulants)
may need to be considered, particularly in cost effectiveness analysis.
- If the evidence allows, NICE will provide guidance on sub-groups of
patients who particularly benefit from these technologies.
- We are aware that many of the drug-eluting stents are not currently
approved. To be included, stents will have to have EU/UK approval (CE
marking) during the time-span of the appraisal (currently to March 2003).
Manufacturers whose products do not meet the deadline in this appraisal
may wish to seek early review of this guidance.
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1 The Dept. of Health/National Assembly for Wales remit to the Institute
is "As part of the planned review of guidance on coronary artery stents, to
appraise the clinical and cost effectiveness of drug eluting stents compared
with conventional stents for the primary prevention of restenosis following
PTCA."
This page was last updated: 30 March 2010