A cost-utility analysis of transcatheter aortic valve implantation in Belgium: focusing on a well-defined and identifiable population

Abstract

Background: Patients with severe aortic stenosis and coexisting non-cardiac conditions may be at high risk for surgical replacement of the aortic valve or even be no candidates for surgery. In these patients, transcatheter aortic valve implantation (TAVI) is suggested as an alternative. Results of the PARTNER (Placement of AoRTic TraNscathetER Valve) trial comparing the clinical effectiveness of TAVI with surgical valve replacement and standard therapy were published. The authors assessed the cost-effectiveness of TAVI in Belgium.

Methods: A Markov model of incremental costs, effects (survival and quality of life) and incremental cost-effectiveness of TAVI was developed. The impact on survival, number of events and quality of life was based on the PARTNER trial. Costs per event were context specific.

Results: In high-risk operable patients, even if the minor differences in 30-day and 1-year mortality are taken into account, the incremental cost-effectiveness ratio (ICER) remains on average above €750 000 per quality-adjusted life-year (QALY) gained (incremental cost: €20 400; incremental effect: 0.03 QALYs). In inoperable patients, an ICER of €44 900 per QALY (incremental cost: €33 200; incremental effect: 0.74 QALYs) is calculated, including a life-long extrapolation of the mortality benefit. This result was sensitive to the assumed time horizon. The subgroup of anatomically inoperable patients had better outcomes than medically inoperable patients, with ICERs decreasing more than €10 000/QALY.

Conclusions: It is inappropriate to consider reimbursement of TAVI for high-risk operable patients. Reimbursing TAVI in inoperable patients in essence is a political decision. From an economic perspective, it would be prudent to first target patients that are inoperable because of anatomical prohibitive conditions. In the search for evidence, the authors identified non-published negative results from a randomised controlled TAVI trial. The study sponsor should be more willing to share this information to allow balanced evaluations and policy recommendations. Payers should require these data before taking reimbursement decisions.

Figure 1

The TAVI Markov model. AVR, aortic valve replacement; ST, standard therapy; TAVI, transcatheter aortic valve implantation. The green square is a choice node, the red dots are chance nodes and the blue triangles are end nodes. Etc.: this indicates that if the patient survives, he goes to the next cycle in the Markov model. In each monthly cycle, the patient is again at risk of dying, being hospitalised, having other events or no event.

Figure 2

Cost-effectiveness plane (top) and cost-effectiveness acceptability curve (bottom) for TAVI in inoperable patients. The green curve on the cost-effectiveness plane is the 95% confidence ellipse.

Figure 3

TAVI's cost-effectiveness. ICER, incremental cost-effectiveness ratio; QALY, quality-adjusted life-year. The x-axis indicates the operability of patients. There is an overlap between medically inoperable and high-risk operable patients. Anatomically inoperable patients are readily identifiable. For high-risk operable patients, the ICERs are very high (€750 000 per QALY). For inoperable patients, the ICER was on average €45 000 per QALY. Within the latter category, ICERs are better for anatomic inoperable patients and worse for medical inoperable patients.