Cost-utility analysis of transcatheter aortic valve implantation in Belgium

Posted On 2012-08-06 11:21:36

A significant percentage of patients with severe aortic stenosis and coexisting co-morbidities are considered high-risk for surgical aortic valve replacement (SAVR) or not considered candidates for surgery at all. For 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 have been published (1,2).

In a recent article published in BMJ Open, Neyt et al. from the Belgian Health Care Knowledge Centre (KCE) in Brussels, Belgium present a cost-utility analysis of TAVI in Belgium (3). 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. 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) remained 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) was 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.

The authors conclude that it would be inappropriate to consider reimbursement of TAVI for high-risk operable patients, and that reimbursing TAVI in inoperable patients would in essence be a political decision. The authors suggest that from an economic perspective, it would be prudent to first target patients that are inoperable because of anatomical prohibitive conditions. 

This analysis comes in the context of other recently published similar evaluations from other countries:

Reynolds et al. report data regarding survival, quality of life, medical resource use, and hospital costs collected during the PARTNER trial (cohort B, inoperable patients). (4) These data were used to project life expectancy, quality-adjusted life expectancy, and lifetime medical care costs to estimate the incremental cost-effectiveness of TAVR from a US perspective. For inoperable patients treated with TAVR, mean costs for the initial procedure and hospitalization were $42 806 and $78 542, respectively. Follow-up costs through 12 months were lower with TAVR ($29 289 versus $53 621) because of reduced hospitalization rates, but cumulative 1-year costs remained higher ($106 076 versus $53 621). The authors projected that over a patient's lifetime, TAVR would increase discounted life expectancy by 1.6 years (1.3 quality-adjusted life-years) at an incremental cost of $79 837. The incremental cost-effectiveness ratio for TAVR was thus estimated at $50 200 per year of life gained or $61 889 per quality-adjusted life-year gained. These results were stable across a broad range of uncertainty and sensitivity analyses.

The authors conclude that for patients with severe aortic stenosis who are not candidates for surgery, TAVR increases life expectancy at an incremental cost per life-year gained well within accepted values for commonly used cardiovascular technologies.

Watt et al. assessed the cost-effectiveness of TAVI compared with medical management in patients with severe aortic stenosis who are ineligible for conventional aortic valve replacement (SAVR) from the perspective of the UK National Health Service. In their study, a decision analytical model was developed to assess the costs and benefits associated with both interventions over a 10-year time horizon. A literature review was performed to identify relevant clinical evidence. Health-related quality of life and mortality were included using data from the PARTNER clinical trial (cohort B). Unit costs were taken from national databases. Costs and benefits were discounted at 3.5% per year, and extensive sensitivity analyses (probabilistic and deterministic) were performed to explore the impact of uncertainty on the cost-effectiveness estimates. The main outcome measure was the incremental cost-effectiveness ratio (ICER) with benefits expressed as quality-adjusted life years (QALYs). The base case ICER was approximately £16,100 per QALY gained. At a cost-effectiveness threshold of £20,000 per QALY gained, the probability that TAVI was cost-effective compared with medical management was 1.00. The results were robust to changes in key clinical parameters as well as choice of baseline survival data. The observed PARTNER survival data only have to be extrapolated for 2 years to generate an ICER below £30,000 per QALY gained, which is the upper value of the threshold range used by the National Institute for Health and Clinical Excellence in the UK.

The authors conclude that TAVI is highly likely to be a cost-effective treatment for patients with severe aortic stenosis who are currently ineligible for SAVR.

1. Leon MB, Smith CR, Mack M, et al. PARTNER Trial Investigators. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery. N Engl J Med. 2010;363:1597-607.
2. Smith CR, Leon MB, Mack MJ, et al. PARTNER Trial Investigators.Transcatheter versus surgical aortic-valve replacement in high-risk patients. N Engl J Med. 2011;364:2187-98. 
3. Neyt M, Van Brabandt H, Devriese S, Van De Sande S. A cost-utility analysis of transcatheter aortic valve implantation in Belgium: focusing on a well-defined and identifiable population. BMJ Open. 2012 May 4;2(3). pii: e001032. 
4. Reynolds MR, Magnuson EA, Wang K, Lei Y, Vilain K, Walczak J, Kodali SK, Lasala JM, O'Neill WW, Davidson CJ, Smith CR, Leon MB, Cohen DJ; PARTNER Investigators. Cost-effectiveness of transcatheter aortic valve replacement compared with standard care among inoperable patients with severe aortic stenosis: results from the placement of aortic transcatheter valves (PARTNER) trial (Cohort B). Circulation. 2012 Mar 6;125(9):1102-9. 
5. Watt M, Mealing S, Eaton J, Piazza N, Moat N, Brasseur P, Palmer S, Busca R, Sculpher M. Cost-effectiveness of transcatheter aortic valve replacement in patients ineligible for conventional aortic valve replacement. Heart. 2012 Mar;98(5):370-6.