Abstract 4119874: Cost Effectiveness Analysis of Surgical Strategies Versus Medical Management for Rheumatic Heart Disease in Rwanda

Background: One third of the Rheumatic Heart Disease (RHD) burden is in sub-Saharan Africa. Without valve surgery, 17% of patients die. However, surgery is often deemed too expensive in this region despite the lack of cost-effectiveness analyses to support this assumption. Aim: Assess the cost-effectiveness of surgical strategies for RHD performed in Rwanda. Methods: We built a Markov model to simulate the progression of patients through different health states. We compared mechanical valve replacement, bioprosthetic valve replacement, and valve repair to medical management for patients with severe RHD. Probabilities of transitioning into different health states were derived from regional published studies. Micro-costing data was obtained from the cardiac surgery program to calculate total costs for each health state. Health effects were measured in quality-adjusted life years (QALYs) from the 2019 Global Burden of Disease Study. Sensitivity analysis was performed to account for model uncertainty. We used a willingness-to-pay threshold of three times the GDP per capita of Rwanda (USD$769). Results: All surgical strategies extended life expectancy compared to medical management, which only offered 5.05 QALYs. Mechanical valve replacement surgery was cost-effective with 11.31 QALYs for a lifetime cost of USD$10,721. The incremental cost effectiveness ratio compared to medical management was USD$1,596/QALY, which is below the willingness to pay threshold. Decreasing the initial cost of surgery and probability of long term stroke increased cost-effectiveness. Although bioprosthetic valve replacement and repair provided 6.43 and 5.70 additional QALYs compared to medical management, they had higher lifetime costs than mechanical valve replacement ($19,789.21, $22,477.27). As a result, they were not cost-effective. In the sensitivity analysis, they became cost effective if valve degeneration rates were 11% in 2 years from a baseline of 26% for repair, and 8% in 2 years from baseline of 14% for bioprosthetic valves. Conclusion: This study challenges the prevailing assumption that surgery is not cost-effective in Sub-Saharan Africa. Mechanical valve replacement surgery was most cost-effective. Watchful waiting with medical management is inexpensive but carries an average life expectancy of 5 years. Identifying cost-saving opportunities for mechanical valve replacement surgery and enhancing anticoagulation monitoring can make it even more economically favorable.