Cost effectiveness of transcatheter aortic valve implantation in patients with aortic stenosis in Japan

Abstract

Background: Transcatheter aortic valve implantation (TAVI) is a less invasive treatment for elderly patients with aortic stenosis. However, the cost of TAVI is a major issue. This study analyzed the cost effectiveness of TAVI in Japan.

Methods: We developed an economic model to evaluate the quality-adjusted life years (QALYs) and costs of TAVI, surgical aortic valve replacement (SAVR), and medical therapy over a 10-year time horizon from the perspective of Japanese public healthcare payers. The first model compared transapical or transfemoral TAVI with Sapien valve implantation and medical therapy in inoperable patients. The second model compared transfemoral TAVI with Sapien XT valve implantation and SAVR in operable patients with intermediate surgical risk. We assumed a cost-effectiveness threshold of 5,000,000yen per QALY, and assessed the cost-effectiveness probability with 100,000 simulations. We performed a broad sensitivity analysis to assess the effect of uncertainty on our results.

Results: Among inoperable patients, the incremental cost-effectiveness ratio for TAVI compared with medical therapy was 3,918,808yen per QALY. In operable patients, the incremental cost-effectiveness ratio for TAVI compared with SAVR was 7,523,821yen per QALY. The cost-effectiveness probability of TAVI was 60% for inoperable patients and 46% for operable patients. Among inoperable patients, the cost-effective threshold of TAVI was <7,759,085yen. Among operable patients, the cost-effective threshold of TAVI was <5,427,439yen.

Conclusions: This study suggests that TAVI has good cost effectiveness for inoperable patients, but not for operable patients.

Keywords: Aortic stenosis; Cost-effectiveness; Incremental cost-effectiveness ratio; Quality-adjusted life year; Transcatheter aortic valve implantation.