Drug-eluting stents: a systematic review and economic evaluation

OBJECTIVESTo assess the effectiveness and cost-effectiveness of the use of drug-eluting coronary artery stents in percutaneous coronary intervention (PCI) in patients with coronary artery disease. DATA SOURCESBibliographic databases, including MEDLINE, EMBASE and the Cochrane Library, were searched from December 2002 to August 2005. Hand-searching was also done. REVIEW METHODSA systematic literature review of effectiveness was conducted focusing primarily on randomised controlled trials (RCTs). Full economic evaluations that compared two or more options and considered both costs and consequences were eligible for inclusion in the economics review. A critique of manufacturer submissions to the National Institute for Health and Clinical Excellence and an economic evaluation in the form of cost-utility analysis were also carried out. RESULTSIn the 17 RCTs of drug-eluting stents (DES) versus bare metal stents (BMS), no statistically significant differences in mortality or myocardial infarction (MI) were identified up to 3 years. Significant reductions in repeat revascularisations were determined for DES compared with BMS [for example, at 1 year: target lesion revascularisation (TLR) relative risk 0.24; 95% confidence interval (CI) 0.19 to 0.31; and target vessel revascularisation (TVR) relative risk 0.43; 95% CI 0.33 to 0.55]. This estimated benefit appears to be stable from 1 to 3 years. Binary restenosis and late luminal loss also favoured DES. In the eight RCTs of DES versus DES, no statistically significant differences in mortality or MI were detected between DES designs. In meta-analyses of TLR, TVR and composite event rate, marginal improvement in efficacy of Cypher trade mark over Taxus trade mark was observed. These results await confirmation beyond 1 year and differences in study design may have influenced reporting of outcomes. Ten full economic evaluations were included in the review and the balance of evidence indicated that DES are more cost-effective in higher risk patients. The review of submitted models confirmed the view that DES may be cost-effective only under very limited circumstances when realistic assumptions and data values were used. In the cost-utility analysis of DES versus BMS, the use of DES appears to reduce the rate of repeat revascularisations; benefit estimates used in the economic assessment are defined as 'broad' (i.e. cases involving any TLR/TVR irrespective of any other lesions/vessels undergoing revascularisation) and 'nar