A systematic review and economic analysis of drug-eluting coronary stents available in Australia

OBJECTIVES: To compare the safety, effectiveness and cost-effectiveness of drug-eluting coronary stents used in Australia with bare-metal stents and determine whether the benefits are greater for high-risk subgroups. DATA SOURCES: MEDLINE, Pre-Medline, EMBASE, Current Contents, CINAHL and the Cochrane Library database were searched to identify eligible randomised controlled trials and systematic reviews published in English between January 1966 and June 2004. STUDY SELECTION: Seven randomised controlled trials that assessed polymer-based paclitaxel- or sirolimus-eluting stents versus bare-metal stents in patients with coronary atherosclerosis and reported on stent thrombosis, mortality, myocardial infarction, coronary artery bypass grafting or target lesion revascularisation. DATA EXTRACTION: Two independent reviewers appraised eligible studies and extracted data. Relative risks (RRs) were calculated for each outcome and pooled using the Mantel-Haenszel method. DATA SYNTHESIS: Rates of stent thrombosis, mortality, myocardial infarction and bypass grafts did not differ by stent type. Drug-eluting stents (DESs) resulted in a 71%-80% lower risk of revascularisation at 12 months (RR 0.29 [95% CI, 0.20-0.43] for paclitaxel-eluting stents [n = 1593 patients]; RR 0.20 [95% CI, 0.13-0.29] for sirolimus-eluting stents [n = 1296 patients]). Similar benefits were seen in several high-risk subgroups of patients: those with diabetes, lesion length > 20 mm and target-vessel diameter < or = 2.5 mm. The benefits of DESs in these high-risk groups over lower-risk groups were inconclusive because of low numbers. The cost per revascularisation avoided by using DESs was 3,750-6,100 Australian dollars, with an estimated cost per quality-adjusted-life-year (QALY) gained of 46,829-76,467 Australian dollars. In sensitivity analyses, estimates varied from DESs being cost-saving to costing an additional 314,385 Australian dollars per QALY gained. CONCLUSIONS: DESs are effective in reducing revascularisation. Estimates of cost-effectiveness are very sensitive to changes in estimates of their true effects in clinical practice, market price and the number of stents used per patient. Decisions to limit DESs to only patients at the highest risk of restenosis may improve their cost-effectiveness but will need to be reassessed when evidence is available to compare absolute benefits between patient groups.