Transcatheter Aortic Valve Implantation (Part I): A systematic review of economic evaluations

Research areas: High tech medicine, Health economics

Project support: Ingrid Zechmeister-Koss
Duration: May 2017 – September 2017
Suggested by: Representatives of federal states
Publication: LBI-HTA Projektbericht No. 95: https://eprints.aihta.at/1139

Language: German (with English abstract)

Background:
Surgical Aortic Valve Replacement (SAVR) is currently considered as the gold standard for the treatment of severe aortic valve stenosis in operable patients. This is a major surgery that requires a sternotomy and the use of a heart-lung bypass machine. In contrast, medication management (MM) is the most common choice for inoperable patients with high surgical risk. However, only a minor benefit in patients with severe, symptomatic aortic stenotic stenosis is attributed to these drug therapies.

For years, transcatheter aortic valve replacement (TAVI) has also been used as an alternative therapy for inoperable patients or for those with high surgical risk. Since TAVI is a less invasive procedure than SAVR, it is also used in patients with moderate surgical risk. Better clinical outcomes in inoperable patients face severe side effects (risk of stroke, vascular complications and paravalvular aortic insufficiency or the need of a permanent pacemaker), and significantly higher costs (multidisciplinary teams of anesthesiologist, cardiologist and surgical specialist).

In order to balance the benefits against monetary as well as non-monetary costs (damage), health-economic analyses were carried out in countries where cost-benefit considerations and/or opportunity costs are systematically taken into account druing the decision making process. These analyses evaluate for which patient group TAVI is cost-effective when being compared with SAVR or MM. Due to the challenging transferability of the results of the health-economic analyses, a methodological basis is provided for a possible calculation for Austria in the future.

Aim of the project:
The goal of part 1 of the project is to systematically extract the parameters (effectiveness, costs, etc.) included in the economic evaluations as well as the exact method of these evaluation for a possible future calculation in Austria.

Furthermore, the results of the health-economic analyses of TAVI vs. MM and/or SAVR should be compared between the following indications:

• inoperable patients
• operable patients with high or intermediate surgical risk

In addition, the selection criteria for TAVI candidates in Austria will be determined in order to facilitate the data evaluations in part 2 of the project.

The aim of the project is NOT to perform a clinical efficacy and safety analysis. This has been evaluated in previous projects (Gottardi, R. and Wild, C. (2011): Minimal-invasiver perkutaner Aortenklappenersatz (mit Exkurs zu Hybrid-OPs). Decision Support Document 18/Update 2011, etc.) and will be evaluated in current projects (EUnetHTA: TAVI in intermediate-risk patients, ongoing, etc.).

Research questions:

1)      Which parameters (effectiveness, costs, etc.) were included in the health-economic analyses and which methodological characteristics were used for the analyses?

2)      What are the results (effectiveness, costs, incremental cost-effectiveness ratios) of the health-economic analyses of TAVI compared to MM and/or SAVR for both patient collectives?

3)      What are the criteria by means of which patients are selected for the TAVI procedure in Austria?

Inclusion criteria (PICO):

Population	Patients with severe aortic stenosis: Inoperable patients Operable patients with high or intermediate surgical risk based on the EuroSCORE or STS-PROM score
Intervention, Setting	Transcatheter Aortic Valve Implantation (TAVI)
Control	For inoperable patients: Medical Management (MM) For operable patients with high or intermediate surgical risk: Surgical Aortic Valve Replacement (SAVR) Medical Management (MM)
Outcomes	Effectiveness: Life-years gained (LYGs) Quality of life (QoL) Need of permanent pacemaker Quality-adjusted life-years (QALYs) Etc. Costs:  Direct costs Procedure Hospital stay Adverse event treatments Follow-up treatments                  •    Cardiology                  •    Electrocardiography                  •    Echocardiography Follow-up treatments Follow-up treatment of adverse events Re-intervention Etc. Indirect costs  Absenteeism  Early retirements Premature death Etc. Incremental cost-effectiveness ratios
Types of studies	(Health-) economic analyses (CEA, CUA, CBA)
Publication period	2007 – 2017
Language	German/English
Type of publications	Peer-reviewed journal articles and HTA reports

 

Methods:

Methods to answer research questions 1 + 2: Systematic review from published materials:

• Literature search:

            o   EconLit, Cochrane (CENTRAL), Centre for Research and Dissemination (CRD), Embase, Medline, NHS Economic Evaluation Database und Medline via Ovid

o   Time period: 2007-2017.

o   Hand search in references (Scopus), internet-search

• Data extraction: Two review authors include and exclude studies independently from each other. One author extracts the data and a second author controls the extracted data.
• Assessing risk of bias and strength of evidence
• Research question 1: Presentation of parameters and methodological characteristics of the health-economic evaluations.
• Research question 2: Comparison of the results of the cost-effectiveness analyse for TAVI vs. SAVR and/or MM. To facilitate the comparability of the results of the costs, costs are converted to the Austria price levels and adjusted to the inflation rate.

In order to answer the research question 3 the TAVI-performing clinics in Austria will be contacted and the selection criteria will be raised.

Time schedule:

Period	Task
Beginning of May 2017	Scoping, precision of PICO-questions
May – Beginning of June 2017	Systematic literature search, non-systematic hand search, literature selection, contacting clinics
June – July 2017	Data extraction, synthesis and assessing of evidence
August 2017	Writing of report
September 2017	Internal and external review, finalising, publication