Coronary artery stents: a rapid systematic review and economic evaluation

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

Electronic databases.

The review was conducted following accepted guidelines for conducting systematic reviews. Randomised controlled trials that include comparisons of percutaneous transluminal coronary angioplasty (PTCA) versus PTCA with stent, stent versus coronary artery bypass graft (CABG), and drug-eluting stents (DES) versus non-DES in patients with CAD in native or graft vessels and those with stable angina or acute coronary syndrome (ACS) and unstable angina were also included. Data on the following outcome measures were included in the review: combined event rate or event-free survival, death, acute myocardial infarction, target vessel revascularisation, repeat treatment (PTCA, stent or CABG) and binary restenosis. An economic model was developed based on extrapolation of trends in mortality and revascularisation from clinical trials data to a 5-year time horizon.

The inclusion criteria were fulfilled by 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. Existing quality of life data suggest that revascularisation procedures reduce the patient's quality of life for a short period only. Stents were found to be more effective than PTCA in preventing adverse events and revascularisations. 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. Patients treated surgically required fewer revascularisations. There is no evidence of a difference in mortality between patients receiving DES and those treated with bare metal stents at 1 year. A reduction in event rate at 9 and 12 months was found 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. The economic model proved sufficient to indicate long-term trends in cost-effectiveness. CABG was found initially to be more expensive than bare metal stenting in multivessel disease and may have higher immediate risks, but over time the cost differential is reduced and long-term outcomes favour CABG over stenting. A similar situation was found for DES versus CABG in multiple-vessel disease. However, DES may not generally be considered a cost-effective alternative to bare metal stenting in single-vessel disease by policy makers as substantially higher costs are involved with a very small outcome benefit.

DES might be considered cost-effective if the additional cost (compared with ordinary stents) was substantially reduced, the outcome benefits from the use of DES were much improved, and/or its use were targeted on the subgroups of patients with the highest risks of requiring reintervention. Long-term clinical studies are needed that focus on significant outcomes such as mortality. Further research should consider: the differences among plain stents; head-to-head comparisons within DES, CABG compared with DES; and the 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 would also be useful, as would the development and testing of risk assessment tools to identify patients likely to need further revascularisations.