Introduction
Aortic stenosis is the most prevalent valvular heart lesion requiring surgical aortic valve replacement (SAVR) or transcatheter aortic valve implementation (TAVI) in Europe and the United States [
1]. As a consequence of aging, its prevalence is rising [
2]. In the pre-TAVI era, patients at high surgical risk had no access to alternative treatment when surgical risk of death was unacceptably high. TAVI has been developed as a less invasive therapeutic alternative for such patients, to improve their quality of life and prognosis. In the past years, significant improvements in TAVI treatment and subsequent improvements in outcome compared with SAVR have led to increasing adoption of TAVI [
3‐
5].
Generally, the indication for SAVR or TAVI is assessed by the Heart Team (consisting of at least a cardiologist and cardiothoracic surgeon), which includes an all-around risk assessment and an evaluation of the feasibility of the procedure. Initially, only high-risk patients were selected for TAVI based on available data [
6,
7]. However, several trials made it possible to select patients for TAVI who had intermediate risk (PARTNER and SURTAVI), and even low risk (PARTNER 3 and Evolut PRO trials).
In 2020, the Dutch National Health Care Institute (
Zorginstituut Nederland) published a report stating that TAVI should no longer be reimbursed for low- and intermediate-risk patients [
8]. The institute requested the Transcatheter Heart Valve Intervention (THI) working group (consisting of cardiologists and cardiothoracic surgeons who are all members of the Netherlands Society of Cardiology (
Nederlandse Vereniging Voor Cardiologie) or Netherlands Society of Thoracic Surgery (
Nederlandse Vereniging voor Thoraxchirurgie)) to draft a document (hereafter: indication document) to define the—to be reimbursed—high-risk population for TAVI. This document was based on the 2017 European Society of Caddiology (ECS)/European Association for Cardio-Thoracic Surgery (EACTS) Guidelines for the management of valvular heart disease [
6,
9] and available data from clinical trials at that time. This indication document was implemented by Heart Teams of all heart centres in the Netherlands on 1 January 2021. As a result, TAVI will only be reimbursed dependent on the patient’s age and the presence of significant comorbidities, as defined in the document. However, in the 2021 ESC/EACTS Guidelines, TAVI is recommended in patients ≥ 75 years of age, irrespective of the absence or presence of comorbidities [
10].
The goal of this study was to evaluate the impact of the indication document on the SAVR and TAVI landscape in the Netherlands, since its implementation in 2021. We therefore evaluated the numbers of procedures and the ratio of SAVR to TAVI, in relation to age and throughout time.
Methods
Data collection
Patient and procedural characteristics and outcome variables were collected from the Netherlands Heart Registry (
Nederlandse Hart Registratie, NHR). The NHR collects data from all 16 Dutch heart centres [
11]. Data analysis for the current objective was approved by the NHR, registry committees for cardiology and cardiothoracic surgery and the THI working groups for cardiology and cardiothoracic surgery. The variables in the indication document [
9] are registered since its implementation in January 2021 and were provided by the NHR. Data for some variables in the indication document could be derived from the NHR data for 2018–2020 (see Table S1 in Electronic Supplementary Material).
Population
This retrospective national study comprised patients who underwent SAVR or TAVI for severe symptomatic aortic stenosis in 2018–2021. Patients with other significant valvular heart disease, an indication for concomitant cardiac surgery or recent (past 3 months) percutaneous coronary intervention or coronary artery bypass grafting were excluded from this study.
Statistical analysis
Continuous variables are presented as median with interquartile range (IQR). Categorical variables are presented as count with percentage. Continuous variables were analysed with the Kruskal-Wallis test or Mann-Whitney U test, whichever was appropriate. Categorical variables were analysed using the chi-square test, Fisher’s exact test or Mann-Whitney U test, whichever was appropriate. Patient characteristics and procedures were compared for the subsequent years, as well as for different age cohorts (all ages, < 75 years, 75–80 years and ≥ 80 years). SPSS Statistics software version 26.0 (IBM Corp., Armonk, NY, USA) was used for the statistical analyses.
Discussion
Since 2021, the Heart Teams of all Dutch 16 heart centres performing AVR procedures (SAVR and TAVI) have to base their decision for SAVR or TAVI in a specific patient upon the national indication document [
8,
9]. This indication document defines which TAVI patients are eligible for reimbursement. The most prominent difference between the criteria in this indication document and the 2021 ESC/EACTS Guidelines for the management of valvular heart disease is that the latter recommends TAVI in patients aged ≥ 75 years [
10], whereas the indication document only allows TAVI in patients < 80 years in case of significant comorbidity.
This analysis focused on the potential changes in the SAVR and TAVI landscape in the Netherlands after the implementation of the indication document. The total number of SAVR plus TAVI procedures and the SAVR/TAVI ratio did not differ in 2021 compared with 2019 and 2020. In addition, baseline characteristics for the TAVI cohort in 2021 did not differ from those in 2019 and 2020. One might therefore argue that the indication document did not change the landscape importantly. However, there are 2 important factors that should be taken into consideration.
First, the indication document might have dampened the potential increase in TAVI in 2021. In other words, without the indication document, what would have happened with the SAVR/TAVI ratio in 2021, after the publication of the new European guidelines in mid-2021? The new guidelines are based on trial data that were already available in 2019. We know that clinical experts generally adapt their practice rapidly, based on published results. In 2019 and 2020, the SAVR/TAVI ratio in the Netherlands was similar to that in 2021, which supports the notion that a potential effect in 2021 was not dampened by the indication document. If, in the most extreme case, all SAVR-treated patients in the age cohort 75–80 years in 2021 would instead have been treated with TAVI, this would have led to an annual increase of 477 TAVI procedures and the percentage of TAVI would have risen from 52 to 63% in 2021.
Second, the COVID-19 pandemic has affected hospital care, starting in March 2020. Did the pandemic create a potential bias with respect to this analysis? Rooijakkers and colleagues from the Radboud University Medical Centre in Nijmegen, the Netherlands showed the COVID-19 pandemic did not have an impact on TAVI patient characteristics and outcome [
13]. In our analysis, we did not find arguments for a COVID-19 effect as the SAVR/TAVI ratios of 2018 (pre-COVID year) and 2020 (COVID year) did not differ, making a potential COVID effect less likely.
We analysed separate age cohorts in 2021 because of the discrepancy in age-based recommendations for TAVI between the European guidelines and the indication document (75 versus 80 years, respectively). Based on the criteria of the indication document, for the all age cohort, TAVI was more frequent in patients of older age (≥ 80 and ≥ 85 years), frail patients, patients with a reduced LVEF and those with previous cardiac surgery. These patients had a higher surgical risk profile with a higher risk of postoperative complications, making TAVI the preferred treatment. Rates of the variables ‘age ≥ 80 years’, ‘age ≥ 85 years’ and ‘reduced LVEF’ did not differ from 2018 through 2021. For the age group 75–80 years, similar findings were seen. This illustrates that consistent decisions have been made throughout the years and the indication document did not alter this.
Study limitation
The indication document was implemented by Heart Teams in 2021. To see its full effect on Heart Team decisions, adding another full year could provide more insight into the annual number of procedures of TAVI versus SAVR.
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