Cost Effectiveness of the Sirolimus-Eluting Stent in High-Risk Patients in Canada

Abstract

The cost effectiveness of drug-eluting stents in Canada is debated and deserves further evaluation in high-risk patients. We performed an economic analysis from the third-party payer perspective based on the clinical results and resource-utilization data of the C-SIRIUS (The Canadian Study of the Sirolimus-Eluting Stent in the Treatment of Patients with Long De Novo Lesions in Small Native Coronary Arteries) trial, which examined the safety and efficacy of sirolimus-eluting stents (SES) versus bare metal stents (BMS) in high-risk patients with single long de novo lesions in small coronary arteries. Only inpatient costs were considered, including physician fees. We postulated that the incremental cost required to avoid a repeat revascularization (RR) procedure with BMS versus simple balloon angioplasty (BA) could be considered the willingness to pay (WTP) to avoid restenosis in Canada. We assessed the incremental cost-effectiveness ratio (ICER) of SES compared with BMS in these high-risk patients compared with WTP. Results are expressed in 2003 Canadian dollars. With a 7% absolute reduction in the need for RR compared with BA, BMS are associated on average with an ICER of US dollars 12,551/RR avoided (RRA) in Canada. In C-SIRIUS, SES further reduced the need for RR at 1 year from 22% to 4% (p = 0.015) compared with BMS. With a 1.5 stent-to-lesion (STL) ratio and an SES retail price of US dollars 2,700 compared with US dollars 700 for BMS, the ICER of SES versus BMS was US dollars 11,275/RRA -- borderline cost effective compared with the implicit WTP of US dollars 12,551 for such health benefit in Canada. Using a lower STL ratio (1.2) would improve the ICER to US dollars 7941/RRA. Treatment of long lesions in small vessels with SES increases net healthcare costs. However, the ICER for SES compares favorably with the currently accepted comparator, i.e. BMS, to reduce coronary restenosis -- at least for higher risk patients undergoing single-vessel revascularization.