BACKGROUND: Controversy exists when managing young patients with aortic valve stenosis. Aortic valve replacement (AVR) with a mechanical prosthesis requires long-term anticoagulation and patients have an increased risk of thromboembolism and bleeding. The Ross procedure is proposed as an alternative, but it is associated with higher procedure costs and increased risk of cardiac re-interventions. We sought to determine the incremental cost per life year gained between the Ross procedure and mechanical AVR in patients under 55 years old with aortic stenosis.
METHODS AND RESULTS: A Markov model with 1-year cycles was developed to determine the long-term costs and benefits associated with the Ross procedure and mechanical AVR in this patient group. The model included 5 health states: well/no complication, major bleeding, thromboembolism, cardiac re-intervention, and death. The start time of the model was the average age at the index surgery (40 years old) and continued for a time horizon of 40 years. Transition probabilities between health states were obtained from meta-analyses on Ross procedure (63 studies) and mechanical AVR (27 studies) outcomes. Costs were obtained from literature, Ontario Health Insurance Plan billing, and our institution. Benefits were expressed in terms of life years (LYs). A discount rate of 1.5% was applied for future costs and benefits and the analyses were conducted from a third-party payer perspective. Univariate sensitivity analysis was conducted by varying the risks of thromboembolism, cardiac re-intervention, time horizon, cost of the Ross procedure, and discount rate. A probabilistic analysis using Monte Carlo simulations was conducted to deal with model parameter uncertainty. Results: The incremental life years gained is 2.87 years in favour of the Ross procedure, with an associated incremental cost of $5,888.86, yielding an ICER of $2,051.87 per life year gained. The biggest determinants of cost-effectiveness were the rate of re-interventions in the Ross group and risk of thromboembolism (stroke) in the mechanical AVR group. The Ross procedure was always cost-effective at a willingness to pay threshold of $50,000 per life year gained.
CONCLUSION: Our results indicate that the Ross procedure is a cost-effective alternative in comparison to mechanical AVR in non-elderly patients with aortic stenosis. However, the current body of evidence is highly subjected to expertise and publication bias. Additional data is required from a well conducted large randomized control trial for more accurate conclusions. Results from this economic evaluation can inform policy makers and future cardiac surgery guidelines.