Transcatheter aortic valve replacement in nonsurgical candidates with severe, symptomatic aortic stenosis: a cost-effectiveness analysis

A Systematic Review and Statistical Analysis of Factors Influencing the Cost-Effectiveness of Transcatheter Aortic Valve Implantation for Symptomatic Severe Aortic Stenosis

Objective

Transcatheter aortic valve implantation (TAVI) is a disruptive technology recommended for patients with symptomatic severe aortic stenosis (sSAS). Despite being available for over 15 years in Europe, with an extensive volume of clinical and economic evaluations across all surgical risk groups, there is little evidence on the identification of the key drivers of TAVI's cost-effectiveness. This study sought to identify these factors and quantify their role.

Methods

A systematic literature review was conducted to identify published economic evaluations of TAVI. This was supplemented by health technology assessment reports. The primary outcome was the likelihood of TAVI being found cost-effective. Secondary outcomes of TAVI being dominant, and the incremental health benefits of TAVI were also explored.

Results

Forty-two studies, reporting 65 unique analyses, were identified. TAVI was found to be cost-effective and dominant in 74% and 20% of analyses, respectively. The latest generation balloon-expandable TAVI device (SAPIEN 3) was more likely to be found cost-effective, as was TAVI use in low-risk populations and when performed via transfemoral access route. There was heterogeneity in the approach taken to economic modelling, which may also influence estimates of cost-effectiveness. Analyses that found TAVI to be dominant always compared it to surgery and usually considered the latest generation balloon-expandable TAVI device. Largest health benefits were observed for the inoperable risk group.

Conclusion

For patients with sSAS, TAVI is typically a cost-effective treatment option. There are important differences by device generation, risk group and access route. It is crucial to consider these differences when appraising the health economic evidence-base for TAVI.

Transcatheter aortic valve implantation in patients with severe symptomatic aortic valve stenosis: systematic review of cost-effectiveness analysis

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is a less invasive and costly treatment for patients with severe aortic stenosis (AS). This study aimed to systematically review the published literature focusing on economic evaluation of TAVI compared with other alternative treatments in AS populations.

METHODS

A systematic review was conducted from inception until May 2021 using PubMed, Scopus, Web of science and Embase databases. The qualities of included studies were evaluated using Consolidated Health Economic Evaluation Reporting Standard (CHEERS) criteria. Data of costs, outcomes, incremental cost-effectiveness ratio (ICER) and willingness to pay were extracted. To compare results, ICERs were converted to the 2020 United States dollar (USD) rate.

RESULTS

Of the 29 included cost-effectiveness studies, TAVI was cost-effective in all studies in the low-risk group (3/3), 77% of studies (7/9) in the intermediate-risk group, half of the studies (6/12) in the high-risk group, and 83% of studies (10/12) in the inoperable group. When adjusted to USD 2020, ICERs ranged from USD 2741 to 1027,674 USD per quality-adjusted life-year gained. The overall quality of the studies ranged from moderate to high.

CONCLUSIONS

TAVI is potentially a cost-effective alternative to surgical aortic valve replacement (SAVR) for patients with operable AS with low, intermediate or high risk compared with medical management (MM) for patients with inoperable AS. TAVI was associated with a significant gain in quality-adjusted life-years in almost all studies compared to either SAVR or MM. TAVI is a costly procedure; therefore, justifying its cost-effectiveness depends on the acceptable threshold in each country.

The transcatheter aortic valve implantation: an assessment of the generalizability of the economic evidences following a systematic review

OBJECTIVES

Scientific literature debates on the economic affordability of transcatheter aortic valve implantation (TAVI) in order to give a useful support to decision makers aiming at establishing a reimbursement scheme for TAVI. For this reason, it is important to assess the quality and the generalizability of the existing economic evidences.

METHODS

The first step was to run a literature search according to a predefined population, intervention, comparator, and outcome on the cost and effectiveness of the TAVI procedure in comparison to medical therapy and traditional surgery. Second, a manual search was carried out on the Web sites of the main HTA agencies. Third, the checklist developed by Augustovski et al. was applied in order to assess the quality and the generalizability of the articles resulting from the selection process.

RESULTS

Overall, 106 articles were obtained. Of these, sixty-five articles were excluded since the title was not consistent with the objective. Further selection took place after abstract and full-text reading. In the end, thirty-one documents were included for the review. According to the checklist, none of the articles was considered generalizable and only one was considered transferable which compares the TAVI procedure with Medical Management in inoperable patients.

CONCLUSIONS

Despite the overall quality of the selected studies was considered good, there is still a lack of evidence on whether evidences generated in different contexts can be considered generalizable. Further research on resource consumption and preferences is needed in order to provide decision makers with more robust evidences.

Real-World Health-Economic Considerations Around Aortic-Valve Replacement in a Publicly Funded Health System

Herein, we describe the unique interplay among biomedical ethics, principles of distributive justice, and economic theory to highlight the role of health technology assessments to compare therapeutic options for aortic valve replacement. From the perspective of the Canadian health care system, transcatheter aortic-valve implantation is associated with higher costs but also higher incremental health benefits compared with surgical aortic-valve replacement. At current willingness to pay thresholds, transcatheter aortic-valve replacement is likely cost effective across the spectrum of risk, from inoperable patients to those at low surgical risk. However, we highlight the nuances within each subgroup of surgical risk that merit careful consideration by the heart team. Moreover, incorporation of patients and their preferences in decision-making is key. In particular, in young, low-risk patients, there remains uncertainty regarding the optimal treatment, with unique concerns around valve durability, selection of valve prosthesis, and consideration for special procedures such as the Ross procedure. Nonetheless, current research suggests that, universally, patients prefer a less invasive approach compared with a more invasive approach. Finally, we highlight that there remain critical issues around timeliness of access to care and unacceptable geographic inequities across Canada. Further research into alternative funding mechanisms and integrated cross-sector care pathways is necessary to address these issues.

Optimal Allocation of Research Funds under a Budget Constraint

Purpose. Health economic evaluations that include the expected value of sample information support implementation decisions as well as decisions about further research. However, just as decision makers must consider portfolios of implementation spending, they must also identify the optimal portfolio of research investments. Methods. Under a fixed research budget, a decision maker determines which studies to fund; additional budget allocated to one study to increase the study sample size implies less budget available to collect information to reduce decision uncertainty in other implementation decisions. We employ a budget-constrained portfolio optimization framework in which the decisions are whether to invest in a study and at what sample size. The objective is to maximize the sum of the studies' population expected net benefit of sampling (ENBS). We show how to determine the optimal research portfolio and study-specific levels of investment. We demonstrate our framework with a stylized example to illustrate solution features and a real-world application using 6 published cost-effectiveness analyses. Results. Among the studies selected for nonzero investment, the optimal sample size occurs at the point at which the marginal population ENBS divided by the marginal cost of additional sampling is the same for all studies. Compared with standard ENBS optimization without a research budget constraint, optimal budget-constrained sample sizes are typically smaller but allow more studies to be funded. Conclusions. The budget constraint for research studies directly implies that the optimal sample size for additional research is not the point at which the ENBS is maximized for individual studies. A portfolio optimization approach can yield higher total ENBS. Ultimately, there is a maximum willingness to pay for incremental information that determines optimal sample sizes.

Present and future economic impact of transcatheter aortic valve replacement on the Portuguese national healthcare system

INTRODUCTION

Transcatheter aortic valve replacement (TAVR) has changed the treatment paradigm of severe aortic stenosis (AS). Nevertheless, in Portugal the penetration rate of TAVR is still very low and there is a paucity of data regarding its economic impact on the Portuguese healthcare system.

AIMS

To perform an economic analysis of the present and future impact of TAVR in Portugal and to propose health policy recommendations for a new reimbursement model.

METHODS

Hospital data from a high-volume center were used as a sample to calculate the costs of TAVR in Portugal. Information regarding the national penetration rate was derived from the EAPCI Valve for Life initiative. To estimate the future demand for TAVR, three scenarios (S) were constructed: S1, TAVR penetration according to current guidelines; S2, including intermediate-risk patients; and S3, including low-risk patients aged over 75 years.

RESULTS

The total cost of each TAVR procedure in Portugal was 22 134.50 euros for the self-expanding valve (SEV) and 23 321.50 euros for the balloon-expanding valves (BEV). Most of the cost was driven by the price of the valve (SEV 74.5% vs. BEV 81.5%). The current national economic impact is estimated at 12 500 000 euros per year. In S1, the expected penetration rate would be 189 procedures per million population; in S2 we estimated an increase of 28% to 241 procedures per million population and in S3 an increase of 107% to 391 procedures per million population. The total economic impact would increase to 43 770 586 euros in S1 and to 90 754 310 euros in S3.

CONCLUSIONS

TAVR is associated with a significant present and future economic impact on the Portuguese healthcare system. A new model of reimbursement in Portugal should be discussed and implemented.

Economic assessment of traditional surgical valve replacement versus use of transfemoral intervention in degenerative aortic stenosis

INTRODUCTION

The aim of this study was to provide an economic assessment of interventional vs. surgical aortic valve replacement in the context of cost-effectiveness. Aortic stenosis represents the most common form of degenerative valvular heart diseases. As life expectancy increases, an even emerging prevalence is expected. Over decades, surgical replacement was considered as the method of choice. Up to one third of the patients were not eligible for surgery, as their estimated peri-operative risk was too high. In the early 2000s a catheter-based technique has been developed, being an alternative treatment option for patients, considered to be inoperable.

EVIDENCE ACQUISITION

A systematic analysis of current literature was performed from September 2018 to December 2018. All suitable data in the field was obtained from Pubmed and Google/Google scholar. The search terms "TAVI AND costs," "TAVR and costs" and "aortic valve replacement AND costs" was entered in the search field, showing an overall amount of 317 publications. In a next step all obtained publications were screened by expert hand selection.

EVIDENCE SYNTHESIS

Recently the Food and Drug Association (FDA) approved transcatheter aortic valve replacement (TAVR) in the low-risk setting. Nevertheless, concerns on the higher price remain. We performed an analysis of current literature on aortic stenosis and economic aspects. Out of 322 screened publications, 7 studies were found eligible by expert hand selection. Based on the predefined payment readiness of the analyzed healthcare system, TAVR appeared to have a slightly better cost effectiveness. Initial results within the early era seemed to be inconsistent. Recent publications showed, TAVR might be of more cost effectiveness when using the newest generation devices and a profound clinical experience is guaranteed.

CONCLUSIONS

We assume, that TAVR will not only be the method of choice for the treatment of aortic stenosis in many patients. As the valves are getting cheaper, TAVR might even be superior to conventional heart surgery from an economic point of view.

Relative Costs of Surgical and Transcatheter Aortic Valve Replacement and Medical Therapy

Background:

The number of patients treated for aortic valve disease in the United States is increasing rapidly. Transcatheter aortic valve replacement (TAVR) is supplanting surgical aortic valve replacement (SAVR) and medical therapy (MT). The economic implications of these trends are unknown. Therefore, we undertook to determine the costs, inpatient days, and number of admissions associated with treating aortic valve disease with SAVR, TAVR, or MT.

Methods:

Using the Nationwide Readmissions Database, we identified patients with aortic valve disease admitted 2012 to 2016 for SAVR, TAVR, and disease symptoms (congestive heart failure, unstable angina, non–ST-elevation myocardial infarction, syncope). Patients not undergoing SAVR or TAVR were classified as receiving MT. Beginning with the index admission, we estimated inpatient costs, days, and admissions over 6 months.

Results:

Among 190 563 patients with aortic valve disease, the average aggregate 6-month inpatient costs were $59 743 for SAVR, $64 395 for TAVR, and $23 460 for MT. Mean index admission was longer for SAVR (10.0 days) than for TAVR (7.0 day) or MT (5.3 days), but the average number of unplanned readmission inpatient days was 2.0 for SAVR, 3.0 for TAVR, and 4.3 for MT; the average number of total admissions was 1.3 for SAVR, 1.5 for TAVR, and 1.7 for MT ( P <0.01 for all). TAVR index admission costs decreased over time to become similar to SAVR costs by 2016.

Conclusions:

Aggregate costs were higher for TAVR than SAVR and were significantly more expensive than MT alone. However, TAVR costs decreased over time while SAVR and MT costs remained unchanged.

Gender-specific differences in valvular heart disease

The development of new devices and treatment options has greatly increased the interest in heart valve diseases. In this context, the consideration of gender differences in diagnosis, treatment success, and prognosis is of great importance. Available data show that women and men with heart valve disease have different risk profiles, which have a significant impact on treatment outcomes and prognosis.

It is the purpose of this review article to give an overview of gender-related differences in patients with valvular heart disease, regarding clinical presentation, treatment, and outcomes. In light of the emerging treatment possibilities, future research should emphasize the role of gender since both sexes benefit from tailored management.

Episode Payments for Transcatheter and Surgical Aortic Valve Replacement

BACKGROUND

Aortic stenosis is the most common valvular heart disease in the United States. Transcatheter aortic valve replacement (TAVR) is increasingly being adopted as an alternative to surgical aortic valve replacement (SAVR). In an era of value-based payment reform, our objective was to better understand the economic impact of the use of TAVR and SAVR in the United States.

METHODS AND RESULTS

We performed a retrospective cohort study of Medicare beneficiaries who underwent TAVR or SAVR between 2012 and 2015. Using claims from a 20% sample of national fee-for-service Medicare beneficiaries, we calculated episode payments for patients who underwent aortic valve replacement from 90 days before aortic valve replacement through 90 days after hospital discharge. Among 18 804 eligible patients, 6455 underwent TAVR (34.3%), and 12 349 underwent SAVR (65.7%). After adjustment for patient characteristics, episode payments for TAVR were ≈7% lower than for SAVR (TAVR, $55 545 [95% CI, $54 643-56 446] versus $59 467 [95% CI, $58 723-60 211]; P<0.001). Patients with TAVR had higher preprocedural payments, but lower payments during and after the index hospitalization for the procedure. Episode payments increased with increasing comorbidity score for patients undergoing TAVR or SAVR (rate ratio, 1.16 [95% CI, 1.15-1.17]; P<0.001); however, this association was stronger for SAVR (rate ratio, 1.18 [95% CI, 1.17-1.19]) than for TAVR (rate ratio, 1.11 [95% CI, 1.11-1.12]; P<0.001 for interaction). Thus, differences in episode payments between TAVR and SAVR were greatest for the sickest patients but much less in healthier patients.

CONCLUSIONS

TAVR is associated with lower episode payments than SAVR. However, episode payments for TAVR are less influenced by patient comorbidity. Therefore, as TAVR is increasingly used in patients with better baseline health status, the economic advantages of TAVR relative to SAVR may diminish.

Transcatheter aortic valve implantation economics: a grisly reality

Transcatheter aortic valve implantation (TAVI), an established treatment for inoperable and high-risk operable symptomatic patients with severe aortic stenosis with growing numbers of procedures and expanding indications, is an expensive therapy. Cost-effectiveness analyses rely on the value of the incremental cost-effectiveness ratio (ICER), which is the difference in cost between two possible interventions, divided by the difference in their effect. Several analyses have demonstrated that TAVI is cost-effective with an acceptable ICER for the inoperable patient alone and only via the iliofemoral route, while TAVI is more costly and is either less or equally effective as surgery in high-risk operable patients. When use of TAVI is extended to include a larger number of patients suitable for surgery, the overall results become less favorable. Acceptable ICERs should practically equate to the value of the gross domestic product (GDP) per capita in each country; however, the cost of the TAVI kit alone already exceeds the GDP per capita of all moderate- and low-income countries. An overview of the current cost-efficacy issues of TAVI is presented and this grisly reality is discussed, which may hopefully be improved in the future.

Outcomes of surgical and transcatheter aortic valve replacement in the octogenarians-surgery still the gold standard?

BACKGROUND

Contemporary options for aortic valve replacement (AVR) include transcatheter and surgical approaches (TAVR and SAVR). As evidence accrues for TAVR in high and intermediate risk patients, some clinicians advocate that all patients aged over 80 years should only receive TAVR. Our aim was to investigate the utility of SAVR and minimally invasive AVR (mAVR) among octogenarians in the current era of TAVR.

METHODS

From 2002 to 2015, 1,028 octogenarians underwent isolated AVR; 306 TAVR and 722 SAVR, of which 378 patients underwent mAVR. Logistic regression and Cox modeling were used to evaluate overall operative mortality and mid-term survival, respectively. Patients were stratified based on procedural approaches (mAVR or full sternotomy for SAVR, and transfemoral or alternate access for TAVR). Median follow-up was 35 [interquartile range (IQR) 14-65] months.

RESULTS

Compared to SAVR patients, TAVR patients were relatively older (86.2 versus 84.2 years) with co-morbidities such as chronic kidney disease (CKD), diabetes mellitus (DM), cerebrovascular disease (CVD), and prior myocardial infarction (MI), all P<0.05. The mean STS-PROM for the TAVR group was statistically higher, 6.81 versus 5.58 for the SAVR group (P<0.001). The median in-hospital LOS was statistically higher for the SAVR group (P<0.05). Cox proportional hazard modeling, adjusted for temporal differences in procedure and patient selection, identified age, New York Heart Association (NYHA) class III/IV, preoperative creatinine, severe chronic lung disease, prior cardiac surgery as significant predictors of decreased survival (all P<0.05), while type of intervention (approach) was non-contributory. Adjusted operative mortality stratified by procedure approaches was similar between full sternotomy SAVR and mAVR, and between alternative access and transfemoral TAVR.

CONCLUSIONS

After adjusting for confounders, TAVR (regardless of approach), SAVR, and mAVR had comparable operative mortality and mid-term survival. Treatment decisions should be individualized with consensus from a multi-disciplinary heart team, taking into account patient co morbidities, frailty, and quality of life. We believe certain patient groups will still benefit from SAVR even in this elderly population.

Two-year post-discharge costs of care among patients treated with transcatheter or surgical aortic valve replacement in Germany

Background

This study presents data on post-discharge costs of care among patients treated with transcatheter or surgical aortic valve replacement over a two year period.

Methods

Based on a prospective clinical trial, post-discharge utilization of health services and status of assistance were collected for 151 elderly patients via 2250 monthly telephone interviews, valued using standardized unit costs and analysed using two-part regression models.

Results

At month 1 post-discharge, total costs of care are substantially elevated (monthly mean: €3506.7) and then remain relatively stable over the following 23 months (monthly mean: €622.3). As expected, the majority of these costs are related to in-hospital care (~98% in month 1 post-discharge and ~72% in months 2–24). Patients that died during follow-up were associated with substantially higher cost estimates of in-hospital care than those surviving the two-year study period, while patients’ age and other patient characteristics were of minor relevance. Estimated costs of outpatient care are lower at month 1 than during the rest of the study period, and not affected by the event of death during follow-up. The estimated costs of nursing care are, in contrast, much higher in year 2 than in year 1 and differ substantially by gender and type of procedure as well as by patients’ age. Overall, these monthly cost estimates add up to €10,352 for the first and €7467.6 for the second year post-discharge.

Conclusions

Substantial cost increases at month 1 post-discharge and in case of death during follow-up are the main findings of the study, which should be taken into account in future economic evaluations on the topic. Application of standardized unit costs in combination with monthly patient interviews allows for a far more precise estimate of the variability in post-discharge health service utilization in this group of patients than the ones given in previous studies.

Trial registration

German Clinical Trial Register Nr. DRKS00000797.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-017-2432-8) contains supplementary material, which is available to authorized users.

Cost and contribution margin of transcatheter versus surgical aortic valve replacement

OBJECTIVE

To compare the cost of and payments for transcatheter aortic valve replacement (TAVR), a novel and expensive technology, and surgical aortic valve replacement (SAVR).

METHODS

Medicare claims provided hospital charges, payments, and outcomes between January and December 2012. Hospital costs and charges were estimated using hospital-specific cost-to-charge ratios. Costs and payments were examined in propensity score- matched TAVR and SAVR patients.

RESULTS

Medicare spent $215,770,200 nationally on 4083 patients who underwent TAVR in 2012. Hospital costs were higher for TAVR patients (median, $50,200; interquartile range [IQR], $39,800-$64,300) than for propensity-matched SAVR patients ($45,500; IQR, $34,500-$63,300; P < .01), owing largely to higher estimated medical supply costs, including the implanted valve prosthesis. Postprocedure hospital length of stay (LOS) length was shorter for TAVR patients (median, 5 days [IQR, 4-8 days] vs 7 days [IQR, 5-9 days]; P < .01), as was total intensive care unit (ICU) LOS (median, 2 days [IQR, 0-5 days] vs 3 days [IQR, 1-6 days]; P < .01). Medicare payments were lower for TAVR hospitalizations (median, $49,500; IQR, $36,900-$64,600) than for SAVR (median, $50,400; IQR, $37,400-$65,800; P < .01). The median of the differences between payments and costs (contribution margin) was -$3380 for TAVR hospitalizations and $2390 for SAVR hospitalizations (P < .01).

CONCLUSIONS

TAVR accounted for $215 million in Medicare payments in its first year of clinical use. Among SAVR Medicare patients at a similar risk level, TAVR was associated with higher hospital costs despite shorter ICU LOS and hospital LOS. Overall and/or medical device cost reductions are needed for TAVR to have a net neutral financial impact on hospitals.

Simulation for transthoracic echocardiography of aortic valve

Simulation allows interactive transthoracic echocardiography (TTE) learning using a virtual three-dimensional model of the heart and may aid in the acquisition of the cognitive and technical skills needed to perform TTE. The ability to link probe manipulation, cardiac anatomy, and echocardiographic images using a simulator has been shown to be an effective model for training anesthesiology residents in transesophageal echocardiography. A proposed alternative to real-time reality patient-based learning is simulation-based training that allows anesthesiologists to learn complex concepts and procedures, especially for specific structures such as aortic valve.

Improving the Methods for the Economic Evaluation of Medical Devices

Medical devices (MDs) have distinctive features, such as incremental innovation, dynamic pricing, the learning curve and organisational impact, that need to be considered when they are evaluated. This paper investigates how MDs have been assessed in practice, in order to identify methodological gaps that need to be addressed to improve the decision-making process for their adoption. We used the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist supplemented by some additional categories to assess the quality of reporting and consideration of the distinctive features of MDs. Two case studies were considered: transcatheter aortic valve implantation (TAVI) representing an emerging technology and implantable cardioverter defibrillators (ICDs) representing a mature technology. Economic evaluation studies published as journal articles or within Health Technology Assessment reports were identified through a systematic literature review. A total of 19 studies on TAVI and 41 studies on ICDs were analysed. Learning curve was considered in only 16% of studies on TAVI. Incremental innovation was more frequently mentioned in the studies of ICDs, but its impact was considered in only 34% of the cases. Dynamic pricing was the most recognised feature but was empirically tested in less than half of studies of TAVI and only 32% of studies on ICDs. Finally, organisational impact was considered in only one study of ICDs and in almost all studies on TAVI, but none of them estimated its impact. By their very nature, most of the distinctive features of MDs cannot be fully assessed at market entry. However, their potential impact could be modelled, based on the experience with previous MDs, in order to make a preliminary recommendation. Then, well-designed post-market studies could help in reducing uncertainties and make policymakers more confident to achieve conclusive recommendations. © 2017 The Authors. Health Economics published by John Wiley & Sons, Ltd.

Conceptual model for early health technology assessment of current and novel heart valve interventions

Objective

The future promises many technological advances in the field of heart valve interventions, like tissue-engineered heart valves (TEHV). Prior to introduction in clinical practice, it is essential to perform early health technology assessment. We aim to develop a conceptual model (CM) that can be used to investigate the performance and costs requirements for TEHV to become cost-effective.

Methods

After scoping the decision problem, a workgroup developed the draft CM based on clinical guidelines. This model was compared with existing models for cost-effectiveness of heart valve interventions, identified by systematic literature search. Next, it was discussed with a Delphi panel of cardiothoracic surgeons, cardiologists and a biomedical scientist (n=10).

Results

The CM starts with the valve implantation. If patients survive the intervention, they can remain alive without complications, die from non-valve-related causes or experience a valve-related event. The events are separated in early and late events. After surviving an event, patients can experience another event or die due to non-valve-related causes. Predictors will include age, gender, NYHA class, left ventricular function and diabetes. Costs and quality adjusted life years are to be attached to health conditions to estimate long-term costs and health outcomes.

Conclusions

We developed a CM that will serve as foundation of a decision-analytic model that can estimate the potential cost-effectiveness of TEHV in early development stages. This supports developers in deciding about further development of TEHV and identifies promising interventions that may result in faster take-up in clinical practice by clinicians and reimbursement by payers.

Improvement in Risk Stratification in Transcatheter Aortic Valve Implantation Using a Combination of the Tumor Marker CA125 and the Logistic EuroSCORE

INTRODUCTION AND OBJECTIVES

Conventional risk scores have not been accurate in predicting peri- and postprocedural risk of patients undergoing transcatheter aortic valve implantation (TAVI). Elevated levels of the tumor marker carbohydrate antigen 125 (CA125) have been linked to adverse outcomes after TAVI. We studied the additional value of CA125 to that of the EuroSCORE in predicting long-term mortality after TAVI.

METHODS AND RESULTS

During a median follow-up of 59 weeks, 115 of 422 patients (27%) died after TAVI. Mortality was higher with elevated CA125 (> 30 U/mL) and EuroSCORE (> median) (47% vs 20%, P<.001 and 38% vs 16%, P<.001, respectively). In the multivariable analysis, CA125 (> 30 U/mL) remained an independent predictor of mortality (hazard ratio [HR], 2.16; 95% confidence interval [95%CI], 1.48-3.15; P<.001) and improved the predictive capability of the model (C-statistic: 0.736 vs 0.731) and the net reclassification index (51% 95%CI, 33-73) with an integrated discriminative improvement of 3.5% (95%CI, 0.5-8.4). A new variable (CA125-EuroSCORE) was created, with the combinations of the 2 possible binary states of these variables (+, elevated, -, not elevated; C1: CA125- EuroSCORE-; C2: CA125+ EuroSCORE-; C3: CA125- EuroSCORE+; C4: CA125+ EuroSCORE+). Patients in C1 exhibited the lowest cumulative mortality rate (14% [26 of 181]). Mortality was intermediate for C2 (CA125 > 30 U/mL and EuroSCORE ≤ median) and C3 (CA125 ≤ 30 U/mL and EuroSCORE > median): 27% (8 of 30) and 28% (37 of 131), respectively. Patients in C4 (CA125 > 30 U/mL and EuroSCORE > median) exhibited the highest mortality (55% [44 of 80], P-value for trend<.001).

CONCLUSIONS

CA125 offers additional prognostic information beyond that obtained by the EuroSCORE. Elevation of both markers was associated with a poor prognosis.

Drivers of healthcare costs associated with the episode of care for surgical aortic valve replacement versus transcatheter aortic valve implantation

Objective

Transcatheter aortic valve implantation (TAVI) is generally more expensive than surgical aortic valve replacement (SAVR) due to the high cost of the device. Our objective was to understand the patient and procedural drivers of cumulative healthcare costs during the index hospitalisation for these procedures.

Design

All patients undergoing TAVI, isolated SAVR or combined SAVR+coronary artery bypass grafting (CABG) at 7 hospitals in Ontario, Canada were identified during the fiscal year 2012–2013. Data were obtained from a prospective registry. Cumulative healthcare costs during the episode of care were determined using microcosting. To identify drivers of healthcare costs, multivariable hierarchical generalised linear models with a logarithmic link and γ distribution were developed for TAVI, SAVR and SAVR+CABG separately.

Results

Our cohort consisted of 1310 patients with aortic stenosis, of whom 585 underwent isolated SAVR, 518 had SAVR+CABG and 207 underwent TAVI. The median costs for the index hospitalisation for isolated SAVR were $21 811 (IQR $18 148–$30 498), while those for SAVR+CABG were $27 256 (IQR $21 741–$39 000), compared with $42 742 (IQR $37 295–$56 196) for TAVI. For SAVR, the major patient-level drivers of costs were age >75 years, renal dysfunction and active endocarditis. For TAVI, chronic lung disease was a major patient-level driver. Procedural drivers of cost for TAVI included a non-transfemoral approach. A prolonged intensive care unit stay was associated with increased costs for all procedures.

Conclusions

We found wide variation in healthcare costs for SAVR compared with TAVI, with different patient-level drivers as well as potentially modifiable procedural factors. These highlight areas of further study to optimise healthcare delivery.

HEALTH TECHNOLOGY ASSESSMENTS REPORTING COST-EFFECTIVENESS OF TRANSCATHETER AORTIC VALVE IMPLANTATION

Objectives: Made available since 2002, transcatheter aortic valve implantation (TAVI) is a minimally invasive new intervention which can provide significant survival improvement to patients with aortic stenosis. However, TAVI is expensive and currently not reimbursed by many governments. Some governments and institutions have been conducting health technology assessments (HTAs) to inform their reimbursement decisions. The aim of the present study is to review HTAs that have relied on a cost-effectiveness analysis to inform reimbursement decisions of TAVI.

Methods: A systematic literature review was conducted among published literature as well as reports released by HTA agencies. Predetermined inclusion and exclusion criteria, following the Preferred Reporting System for Systematic Reviews and Meta-Analysis guidelines, were used to select relevant HTAs. The selected papers were assessed against the Consolidated Health Economic Evaluation Reporting Standards.

Results: HTAs on TAVI from three countries were available for this review: Canada, Belgium, and the United Kingdom. All three HTAs used the Placement of Aortic Transcatheter Valve (PARTNER) trial data with Markov models to estimate the incremental cost effectiveness ratio. The three HTAs recommended conditional reimbursement for TAVI for otherwise inoperable patients. The HTAs did not use clear methods to estimate the health-related utility which ultimately affected their cost-effectiveness results. The UK HTA showed the best value for money (US$20,416 per quality-adjusted life-year).

Conclusion: All studies found TAVI to be more costly and less effective for high-risk patients suitable for surgery, whereas TAVI was consistently found to be cost effective for otherwise inoperable patients.

Quality of life among elderly patients undergoing transcatheter or surgical aortic valve replacement- a model-based longitudinal data analysis

Background

Quality of life (QoL) measurements reported in observational studies are often biased, since patients who failed to improve are more likely to be unable to respond due to death or impairment. In order to observe the development of QoL in patients close to death, we analyzed a set of monthly QoL measurements for a cohort of elderly patients treated for aortic valve stenosis (AS) with special consideration of the effect of distance to death.

Methods

QoL in 169 elderly patients (age ≥ 75 years), treated either with transcatheter aortic valve replacement (TAVR; n = 92), surgical aortic-valve replacement (n = 70), or drug-based therapy (n = 7), was evaluated using the standardized EQ-5D questionnaire. Over a two-year period, patients were consulted using monthly telephone interviews or outpatient visits, leading to a total of 2463 time points at which QoL values, New York Heart Association (NYHA) Functional Classification and their status of assistance were assessed. Furthermore, post-procedural clinical events and complications were monitored. Linear and ordered logistic regression analyses with random intercept were carried out, taking into account overall trends and distance to death.

Results

QoL measures decreased slightly over time, were temporarily impaired at month 1 after the initial episode of hospitalization and decreased substantially at the end of life with a measurable effect starting at the sixth from last follow-up (month) before death. Many clinical complications (bleeding complications, stroke, acute kidney injury) showed an impairment of QoL measurements, but the inclusion of lagged variables demonstrated medium term (three months) QoL impairments for access site bleeding only. All other complications are associated with event-related impairments that decreased dramatically at the second and third follow-up interviews (month) after event.

Conclusions

Distance to death shows clear effects on QoL and should be taken into account when analyzing QoL measures in the elderly patients treated for aortic valve stenosis.

Trial registration

German Clinical Trial Register Nr. DRKS00000797

Temporal Trends in Disease Severity and Predicted Surgical Risk at the Time of Referral for Echocardiography in Patients Diagnosed with Aortic Stenosis

BACKGROUND

Calcific aortic stenosis (AS) is the most common underlying pathology in patients undergoing heart valve surgery, with an expected increasing prevalence among the aging population.

METHODS AND RESULTS

We identified the temporal trends in referral patterns, disease severity, and associated surgical risk among patients with AS between January 1, 1995 and December 31, 2012 at the Duke University Hospital. A total of 6103 patients had a finding of mild (n = 3303), moderate (n = 1648), or severe AS (n = 1152) in a native aortic valve. Overall presence of severe AS increased significantly over time (P = 0.009) with the most substantial increase occurring from 2010 and onward. Median age upon referral (P < 0.001) and attendant predicted surgical risk (P < 0.001) increased significantly in the observation period among patients with a finding of severe AS. Among patients with a finding of severe AS, the proportion of patients aged older than 80 years increased to 51.0% in the most recent time period (2010-2012) compared with 32.6% in the preceding time period (P < 0.001 for overall time trend). Similarly, the proportion of patients with a logistic EuroSCORE greater than 20% increased to 21.3% (2010-2012) from 12.1% (pre-2010).

CONCLUSIONS

Among patients referred for echocardiography to a high-volume tertiary hospital center, a significant increase in the prevalence of severe AS was observed over time. This trend occurred in parallel with increasing age and predicted surgical risk at referral. Health-care resource planning should account for an increasing number of patients in need of high-risk aortic valve replacements in the near future.

Transcatheter Aortic Valve Implantation in Lower-Risk Patients With Aortic Stenosis

Transcatheter aortic valve implantation underwent progressive improvements until it became the default therapy for inoperable patients, and a recommended therapy in high-risk operable patients with symptomatic severe aortic stenosis. In the lower-risk patient strata, a currently costly therapy that still has important complications with questionable durability is competing with the established effective and still-improving surgical replacement. This report tries to weigh the clinical evidence, the recent technical improvements, the durability, and the cost-effectiveness claims supporting the adoption of transcatheter aortic valve implantation in intermediate-low risk patients. The importance of appropriate patients’ risk stratification and a more comprehensive approach to estimate that risk are also emphasized in the present report.

Costs and in-hospital outcomes of transcatheter aortic valve implantation versus surgical aortic valve replacement in commercial cases using a propensity score matched model

The aim of this study was to compare in-hospital cost and outcomes between transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR). TAVI is an effective treatment option in patients with symptomatic aortic stenosis who are at high risk for traditional SAVR. Several studies using trial data or outside United States registry data have addressed TAVI cost issues, although there is a paucity of cost data involving commercial cases in the United States. Using Agency for Healthcare Research and Quality Healthcare Cost and Utilization Project Nationwide Inpatient Sample files, a propensity score-matched analysis of all commercial TAVI and SAVR cases performed in 2011 was conducted. Overall hospital cost and length of stay, as well as procedural complications, were compared between the 2 matched cohorts: 595 TAVI patients were matched to 1,785 SAVR patients in a 1:3 ratio. There was no difference in mean ($181,912 vs $196,298) or median ($152,993 vs $155,974) hospital cost between TAVI and SAVR (p = 0.60). The TAVI group had significantly shorter lengths of hospital stay than the SAVR group (mean 9.76 vs 12.01 days, p <0.001). There was no difference in postprocedural in-hospital death or stroke, but TAVI patients were more likely to have bleeding complications, to have vascular complications, and to require pacemakers. In conclusion, when analyzing in-hospital cost of commercial TAVI and SAVR cases using the Nationwide Inpatient Sample data set, TAVI is an economically satisfactory alternative to SAVR and results in an approximately 2-day shorter length of stay during the index hospitalization.

Cost effectiveness of transcatheter aortic valve replacement compared with medical management or surgery for patients with aortic stenosis

BACKGROUND

In the symptomatic patient, severe aortic stenosis (AS) has an extremely adverse prognosis in the absence of valve replacement, inevitably leading to deterioration of heart function, heart failure, and death. However, many patients with severe AS, advanced age, and comorbid disease may die with AS rather than from AS. While the results of surgical aortic valve replacement (SAVR) are extremely favorable, this technique is not always possible because of either local- or patient-level contraindications. Over the last decade, transcatheter aortic valve replacement (TAVR) has emerged as a new treatment strategy for selected patients with AS. It has now become the standard of care for extremely high-risk (inoperable) patients with AS, and is an appropriate alternative to surgery in high-risk but operable patients. However, whether this intervention is a cost-effective use of resources is open to question

AIM

The aim of this review was to assess the results and quality of the economic evaluations in the current literature and to identify the drivers of cost effectiveness.

METHODS

We performed an electronic data search using four different electronic databases, selecting all studies that included cost-effectiveness data for TAVR compared with either medical management or surgery. Sixteen studies were evaluated for a qualitative and quantitative assessment.

RESULTS

The quality of the cost-effectiveness analyses (CEAs) were generally sufficient. In contrast, we found an extreme heterogeneity of input assumptions with consequent difficulties to generalize the conclusions. However, in the population of patients with severe symptomatic AS and a prohibitive surgical risk, TAVR generally represents a good choice, with incremental costs that are well balanced by the great benefit in terms of quality of life and survival. Nevertheless, the cost effectiveness of this procedure in the real world, particularly in patients with high healthcare costs from other comorbid conditions, may be less favorable. In AS patients with high (but not prohibitive) surgical risk, the choice between TAVR and SAVR is still debatable. Both procedures are comparable in terms of efficacy and safety but the evidence is inconclusive from an economic point of view.

CONCLUSIONS

On the basis of this review, it was ascertained that the details of risk evaluation and patient selection will be critical in understanding how improvements in survival can be used to target the use of TAVR to ensure the cost-effective and sustainable use of resources.

Costs of periprocedural complications in patients treated with transcatheter aortic valve replacement: results from the Placement of Aortic Transcatheter Valve trial

BACKGROUND

In patients with severe aortic stenosis, transcatheter aortic valve replacement (TAVR) improves survival when compared with nonsurgical therapy but with higher in-hospital and lifetime costs. Complications associated with TAVR may decrease with greater experience and improved devices, thereby reducing the overall cost of the procedure. Therefore, we sought to estimate the effect of periprocedural complications on in-hospital costs and length of stay of TAVR.

METHODS AND RESULTS

Using detailed cost data from 406 TAVR patients enrolled in the Placement of Aortic Transcatheter Valve (PARTNER) I trial, we developed multivariable models to estimate the incremental cost and length of stay associated with specific periprocedural complications. Attributable costs and length of stay for each complication were calculated by multiplying the independent cost of each event by its frequency in the treatment group. Mean cost for the initial hospitalization was $79 619±40 570 ($50 891 excluding the valve); 49% of patients had ≥1 complication. Seven complications were independently associated with increased hospital costs, with major bleeding, arrhythmia, and death accounting for the largest attributable cost per patient. Renal failure and the need for repeat TAVR, although less frequent, were also associated with substantial incremental and attributable costs. Overall, complications accounted for $12 475 per patient in initial hospital costs and 2.4 days of hospitalization.

CONCLUSIONS

In the PARTNER trial, periprocedural complications were frequent, costly, and accounted for ≈25% of non-implant-related hospital costs. Avoidance of complications should improve the cost-effectiveness of TAVR for inoperable and high-risk patients, but reductions in the cost of uncomplicated TAVR will also be necessary for optimal efficiency.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00530894.

Evaluation of the Edwards Lifesciences SAPIEN transcatheter heart valve

Severe aortic stenosis is a common valvular disease and is associated with both morbidity and mortality. Surgical aortic valve replacement was the only available therapeutic option until technological advances allowed for the development of a transcatheter heart valve system. The first available THV was the Edwards SAPIEN. The merits of this system in terms of safety and efficacy were explored in the pivotal Placement of AoRTic TraNscathetER (PARTNER) randomized trial whose results then led to the approval of this device for commercial use in the US. The valve is now indicated for inoperable patients and may be considered an alternative for surgery for high-risk patients. Two successive models, the XT and more recently the S3, were developed with the intent to improve procedural outcomes. In this article, the SAPIEN transcatheter heart valve family is described in terms of technology, scientific data and future directions.

A simple risk tool (the OBSERVANT score) for prediction of 30-day mortality after transcatheter aortic valve replacement

Risk stratification tools used in patients with severe aortic stenosis have been mostly derived from surgical series. Although specific predictors of early mortality with transcatheter aortic valve replacement (TAVR) have been identified, the prognostic impact of their combination is unexplored. We sought to develop a simple score, using preprocedural variables, for prediction of 30-day mortality after TAVR. A total of 1,878 patients from a national multicenter registry who underwent TAVR were randomly assigned in a 2:1 manner to development and validation data sets. Baseline characteristics of the 1,256 patients in the development data set were considered as candidate univariate predictors of 30-day mortality. A bootstrap multivariate logistic regression process was used to select correlates of 30-day mortality that were subsequently weighted and integrated into a scoring system. Seven variables were weighted proportionally to their respective odds ratios for 30-day mortality (glomerular filtration rate <45 ml/min [6 points], critical preoperative state [5 points], New York Heart Association class IV [4 points], pulmonary hypertension [4 points], diabetes mellitus [4 points], previous balloon aortic valvuloplasty [3 points], and left ventricular ejection fraction <40% [3 points]). The model showed good discrimination in both the development and validation data sets (C statistics 0.73 and 0.71, respectively). Compared with the logistic European System for Cardiac Operative Risk Evaluation in the validation data set, the model showed better discrimination (C statistic 0.71 vs 0.66), goodness of fit (Hosmer-Lemeshow p value 0.81 vs 0.00), and global accuracy (Brier score 0.054 vs 0.073). In conclusion, the risk of 30-day mortality after TAVR may be estimated by combining 7 baseline clinical variables into a simple risk scoring system.

Identifying best-fitting inputs in health-economic model calibration: a Pareto frontier approach

BACKGROUND

To identify best-fitting input sets using model calibration, individual calibration target fits are often combined into a single goodness-of-fit (GOF) measure using a set of weights. Decisions in the calibration process, such as which weights to use, influence which sets of model inputs are identified as best-fitting, potentially leading to different health economic conclusions. We present an alternative approach to identifying best-fitting input sets based on the concept of Pareto-optimality. A set of model inputs is on the Pareto frontier if no other input set simultaneously fits all calibration targets as well or better.

METHODS

We demonstrate the Pareto frontier approach in the calibration of 2 models: a simple, illustrative Markov model and a previously published cost-effectiveness model of transcatheter aortic valve replacement (TAVR). For each model, we compare the input sets on the Pareto frontier to an equal number of best-fitting input sets according to 2 possible weighted-sum GOF scoring systems, and we compare the health economic conclusions arising from these different definitions of best-fitting.

RESULTS

For the simple model, outcomes evaluated over the best-fitting input sets according to the 2 weighted-sum GOF schemes were virtually nonoverlapping on the cost-effectiveness plane and resulted in very different incremental cost-effectiveness ratios ($79,300 [95% CI 72,500-87,600] v. $139,700 [95% CI 79,900-182,800] per quality-adjusted life-year [QALY] gained). Input sets on the Pareto frontier spanned both regions ($79,000 [95% CI 64,900-156,200] per QALY gained). The TAVR model yielded similar results.

CONCLUSIONS

Choices in generating a summary GOF score may result in different health economic conclusions. The Pareto frontier approach eliminates the need to make these choices by using an intuitive and transparent notion of optimality as the basis for identifying best-fitting input sets.