Cost-Effectiveness of Transcatheter Aortic Valve Implantation in Intermediate and Low Risk Severe Aortic Stenosis Patients in Singapore

Abstract

Singapore has the world's second most efficient healthcare system while costing less than 5% GDP. It remains unclear whether transcatheter aortic valve implantation (TAVI) is cost-effective for treating intermediate-low risk severe aortic stenosis (AS) patients in a highly efficient healthcare system. A two-phase economic model combining decision tree and Markov model was developed to assess the costs, effectiveness, and the incremental cost-effectiveness ratio (ICER) of transfemoral (TF) TAVI versus surgical aortic valve replacement (SAVR) in intermediate-low risk patients over an 8-year time horizon. Mortality and complications rates were based on PARTNER 2 trial cohort A and Singapore life table. Costs were mainly retrieved from Singapore National University Health System database. Health utility data were obtained from Singapore population based on the EuroQol-5D (EQ-5D). A variety of sensitivity analyses were conducted. In base case scenario, the incremental effectiveness of TF-TAVI versus SAVR was 0.19 QALYs. The ICER of TF-TAVI was S$33,833/QALY. When time horizon was reduced to 5 years, the ICER was S$60,825/QALY; when event rates from the propensity analysis was used, the ICER was S$21,732/QALY and S$44,598/QALY over 8-year and 5-year time horizons, respectively. At a willingness to pay threshold of S$73,167/QALY, TF-TAVI had a 98.19% probability of being cost-effective after 100,000 simulations. The model was the most sensitive to the costs of TF-TAVI procedure. TF-TAVI is a highly cost-effective option compared to SAVR for intermediate-low risk severe AS patients from a Singapore healthcare system perspective. Increased procedure experience, reduction in device cost, and technology advance may have further increased the cost-effectiveness of TF-TAVI per scenario analysis.