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NIHR Health Technology Assessment programme: Executive Summaries. Southampton (UK): NIHR Journals Library; 2003-.

NIHR Health Technology Assessment programme: Executive Summaries.

Coronary artery stents: a rapid systematic review and economic evaluation

R Hill, A Bagust, A Bakhai, R Dickson, Y Dündar, A Haycox, R Mujica Mota, A Reaney, D Roberts, P Williamson, and T Walley.

Author Information

R Hill,1 A Bagust,1 A Bakhai,2 R Dickson,1,* Y Dündar,1 A Haycox,1 R Mujica Mota,1 A Reaney,3 D Roberts,4 P Williamson,5 and T Walley1.

1 Liverpool Reviews and Implementation Group, Liverpool, UK
2 Clinical Trials and Evaluation Unit, Royal Brompton Hospital, London, UK
3 Royal Liverpool and Broadgreen University Hospital Trust, Liverpool, UK
4 Blackpool, Fylde and Wyre Hospitals NHS Trust, Blackpool Victoria Hospital, Blackpool, UK
5 Centre for Medical Statistics and Health Evaluation, School of Health Sciences, University of Liverpool, UK
* Corresponding author

Published: 2004.


To assess the effectiveness and cost-effectiveness of the use of coronary artery stents in patients with coronary heart disease (CHD).

Specifically, the review compares the use of:

  • stent versus percutaneous transluminal coronary angioplasty (PTCA)
  • stent versus coronary artery bypass graft (CABG)
  • drug-eluting stents (DES) versus non-DES.


CHD is a major cause of morbidity and mortality in the UK. Treatment models include medical management, percutaneous interventions (PCI) and surgery. Although PCI provides initial relief of symptoms, there is a high rate of restenosis and need for repeat treatment. There has been rapid evolution of treatment in the area of coronary artery stents, including the development of drug-eluting stents (DES).

The rapid developments in stenting in the treatment of coronary artery disease (CAD) have made it necessary to re-examine the available research evidence to inform national guidance.


The review was conducted following accepted guidelines for conducting systematic reviews, including the identification of clinical and economic studies, application of inclusion criteria, quality assessment of included studies and data extraction and analysis.

Inclusion criteria

Randomised controlled trials that include comparisons of PTCA versus PTCA with stent, stent versus CABG and non-DES versus-DES in patients with CAD in native or graft vessels and those with stable angina or acute coronary syndrome (ACS) and unstable angina were included in the review. Data on the following outcome measures were included in the review: combined event rate or event-free survival, death, acute myocardial infarction (AMI), target vessel revascularisation, repeat treatment (PTCA, stent or CABG) and binary restenosis.

Full economic evaluations that compared two or more options and considered both costs and consequences, including cost-effectiveness, cost-utility analysis or cost-benefit analysis undertaken in the context of high-quality randomised controlled trials, were included in the review.

Clinical findings

Sixty-eight studies fulfilled the inclusion criteria. These included 50 studies comparing the use of stents with PTCA, six comparing stents with CABG and 12 comparing DES eluting stents with non-DES. No studies were identified that compared DES with PTCA or DES with CABG.

Studies included a variety of stent designs and eluting drugs. In the surgical trials both standard and minimally invasive surgical techniques were reported.

Mortality is a rare event and none of the included studies was powered to assess effectiveness of the treatment in relation to this outcome. The primary outcome in all studies was either a composite end-point such as major adverse cardiac (and/or cerebrovascular) events, a composite event rate made up of death, AMI and revascularisation or revascularisation rate.

Definition of revascularisation rates varied across studies, with some including all target lesion or vessel revascularisation (whether need was clinically or angiographically identified), others reporting only clinically driven rates and others reporting a mix of both. No studies reported total revascularisation (e.g. repeat treatments carried out on target vessels or lesions and treatment to any other vessel).

Studies were not powered to assess effectiveness across groups of high-risk patients (i.e. patients with diabetes, patients with long lesions). Data on subgroups of high-risk patients have been presented within study reports but were not available for further analysis.

Existing quality of life data suggest that revascularisation procedures reduce the patient's quality of life for a short period only.

PTCA versus stent

Data analysis was carried out with studies grouped according to patient characteristics (non-specific, AMI, totally occluded vessels and small vessels).

Stents are more effective than PTCA in preventing adverse events and revascularisations. These results confirm the trends presented in the previous review that informed the national guidance.

Stent versus CABG

All studies were a comparison of bare metal stents with surgery. Studies comparing drug-eluting stents with CABG have commenced but no reports of results are currently available.

Analysis of data was carried out considering patients with single- and multiple-vessel disease. Studies in the former group were small and did not report results that could be used in the analysis past 6-month follow-up.

In multiple-vessel disease there was no evidence of a difference in mortality (at 1 year) between patients treated surgically and those receiving a stent. Longer term data from these studies are now becoming available. Patients treated surgically required fewer revascularisations.

Stent versus DES

Data are limited by the lack of reporting of longer term outcomes. There is no evidence of a difference in mortality between patients receiving DES and those treated with bare metal stents at 1 year.

There is a reduction in event rate at 9 and 12 months in patients treated with DES. This event rate is primarily made up of increased revascularisation rates in patients treated with bare metal stents. Two-year outcome data from one study indicate that this benefit of DES continues over the longer term.

Economic evaluation

The existing economic literature in this area is limited and of variable quality and relevance. The nature of CAD as a life-long condition means that outcomes and costs should be considered over extended time periods. In our view, the submitted company models were inadequate in this respect.

We developed an economic model based on extrapolation of trends in mortality and revascularisation from clinical trials data to a 5-year time horizon. This proved sufficient to indicate long-term trends in cost-effectiveness:

  • Bare metal stenting versus CABG in multivessel disease
  • CABG is initially more expensive and may have higher immediate risks, but over time the cost differential is reduced and long-term outcomes favour CABG over stenting.
  • DES versus CABG in multiple-vessel disease
  • Here the situation is not qualitatively different from bare metal stenting. Reduced costs from fewer repeat revascularisations is more than offset by the higher costs of stents and the improved efficacy of the new stents does not eliminate the long-term outcome advantage of CABG.
  • DES versus bare metal stenting in single-vessel disease. This leads to substantially higher costs with a very small outcome benefit, so that DES would not normally be considered a cost-effective alternative.

DES might be considered cost-effective if one or more of the following options apply:

  • The additional cost of DES (compared with ordinary stents) was substantially reduced.
  • The outcome benefits from the use of DES are much improved.
  • The use of DES is targeted on the subgroups of patients with the highest risks of requiring reintervention.

Implications for the NHS

The net cost implications to the NHS, depending on which patients receive DES, range from £4.2 million to £23 million per year, at current levels of stent provision.

Recommendations for further research

This review indicates a need for research in a number of areas:

  • Long-term clinical studies that focus on significant outcomes such as mortality.
  • Further studies on (a) differences among plain stents (this might be possible from a systematic review, but is not addressed in the current review), (b) head-to-head comparisons within DES (new trial data required), (c) CABG compared with DES (already planned) and (d) evaluation of newer non-DES against DES.
  • Evaluation of the effects of revascularisation procedures and especially repeat revascularisation procedures on the patient's quality of life.
  • Development and testing of risk assessment tools to identify patients likely to need further revascularisations.
  • The rapid rate of change in this area suggests that a further review should be undertaken in 12-18 months.


  • Hill R, Bagust A, Bakhai A, Dickson R, Dundar Y, Haycox A, et al. Coronary artery stents: a rapid systematic review and economic evaluation. Health Technol Assess 2004;8(35). [PubMed: 15361315]

NHS R&D HTA Programme

The research findings from the NHS R&D Health Technology Assessment (HTA) Programme directly influence key decision-making bodies such as the National Institute for Clinical Excellence (NICE) and the National Screening Committee (NSC) who rely on HTA outputs to help raise standards of care. HTA findings also help to improve the quality of the service in the NHS indirectly in that they form a key component of the 'National Knowledge Service' that is being developed to improve the evidence of clinical practice throughout the NHS.

The HTA Programme was set up in 1993. Its role is to ensure that high-quality research information on the costs, effectiveness and broader impact of health technologies is produced in the most efficient way for those who use, manage and provide care in the NHS. 'Health technologies' are broadly defined to include all interventions used to promote health, prevent and treat disease, and improve rehabilitation and long-term care, rather than settings of care.

The HTA programme commissions research only on topics where it has identified key gaps in the evidence needed by the NHS. Suggestions for topics are actively sought from people working in the NHS, the public, consumer groups and professional bodies such as Royal Colleges and NHS Trusts.

Research suggestions are carefully considered by panels of independent experts (including consumers) whose advice results in a ranked list of recommended research priorities. The HTA Programme then commissions the research team best suited to undertake the work, in the manner most appropriate to find the relevant answers. Some projects may take only months, others need several years to answer the research questions adequately. They may involve synthesising existing evidence or designing a trial to produce new evidence where none currently exists.

Additionally, through its Technology Assessment Report (TAR) call-off contract, the HTA Programme is able to commission bespoke reports, principally for NICE, but also for other policy customers, such as a National Clinical Director. TARs bring together evidence on key aspects of the use of specific technologies and usually have to be completed within a limited time period.

Criteria for inclusion in the HTA monograph series

Reports are published in the HTA monograph series if (1) they have resulted from work commissioned for the HTA Programme, and (2) they are of a sufficiently high scientific quality as assessed by the referees and editors.

Reviews in Health Technology Assessment are termed 'systematic' when the account of the search, appraisal and synthesis methods (to minimise biases and random errors) would, in theory, permit the replication of the review by others.

The research reported in this monograph was commissioned and funded by the HTA Programme on behalf of NICEas project number 02/16/01. The authors have been wholly responsible for all data collection, analysis and interpretation and for writing up their work. The HTA editors and publisher have tried to ensure the accuracy of the authors' report and would like to thank the referees for their constructive comments on the draft document. However, they do not accept liability for damages or losses arising from material published in this report.

The views expressed in this publication are those of the authors and not necessarily those of the HTA Programme, NICE or the Department of Health.

HTA Programme Director: Professor Tom Walley

Series Editors: Dr Peter Davidson, Professor John Gabbay, Dr Chris Hyde, Dr Ruairidh Milne, Dr Rob Riemsma and Dr Ken Stein

Managing Editors: Sally Bailey and Caroline Ciupek

© 2004 Crown Copyright.

Included under terms of UK Non-commercial Government License.

PMID: 15361315

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