Cost-effectiveness of transcatheter aortic valve implantation compared to surgical aortic valve replacement in the intermediate surgical risk population

Background: The recent PARTNER S3i trial compared transcatheter aortic valve implantation (TAVI) using the third-generation SAPIEN 3 device to surgical aortic valve replacement (SAVR) in intermediate-risk patients with severe symptomatic aortic stenosis. Using data from PARTNER S3i, we performed a contemporary cost-effectiveness analysis of current-generation TAVI versus SAVR from the Australian healthcare system perspective. Methods: A Markov model with monthly cycles and a ten-year horizon was constructed to estimate costs, life-years and quality adjusted life-years (QALYs) associated with TAVI and SAVR. Efficacy inputs were derived from the PARTNER S3i study. Costs were estimated from published sources. Deterministic and probabilistic sensitivity analyses were performed to assess model uncertainty. Results: TAVI was found to have higher immediate procedural costs than SAVR, driven primarily by the cost of the transcatheter valve. This was offset by a shorter length of hospitalisation following TAVI, such that the combined cost of initial procedure and hospitalisation was lower in TAVI compared to SAVR. With 5% annual discounting, total costs over ten-years were $50,515 AUD in TAVI and $60,144 AUD in SAVR, and TAVI was found to produce 0.33 more life years and 0.31 more QALYs than SAVR. Thus, from a health economic perspective, TAVI was dominant compared to SAVR. Results were robust to sensitivity analyses, with TAVI being dominant in 68% of 10,000 Monte Carlo iterations and cost-effective in 92% of iterations at a willingness-to-pay threshold of $50,000/QALY gained. Conclusions: TAVI is likely to be highly cost-effective compared to SAVR in intermediate-risk patients with severe aortic stenosis.