Cost-effectiveness of drug-eluting coronary stents in Quebec, Canada

Coronary Stenting: Reflections on a 35-Year Journey

Stenting was introduced as a therapy for coronary artery disease 35 years ago, and is currently the most commonly performed minimally invasive procedure globally. Percutaneous coronary revascularization, initially with plain old balloon angioplasty and later with stenting, has dramatically affected the outcomes of acute myocardial infarction and acute coronary syndromes. Coronary stenting is probably the most intensively studied therapy in medicine on the basis of the number of randomized clinical trials for a broad range of indications. Continuous improvements in stent materials, design, and coatings concurrent with procedural innovations have truly been awe-inspiring. The story of stenting is replete with high points and some low points, such as the initial experience with stent thrombosis and restenosis, and the more recent disappointment with bioabsorbable scaffolds. History has shown rapid growth of stent use with expansion of indications followed by contraction of some uses in response to clinical trial evidence in support of bypass surgery or medical therapy. In this review we trace the constantly evolving story of the coronary stent from the earliest experience until the present time. Undoubtedly, future iterations of stent design and materials will continue to move the stent story forward.

An Analysis of Cost-Effectiveness of Stents Used in the Treatment of Coronary Artery Disease

Background:

There is only limited information about the cost-effectiveness of drug-eluting stents compared with bare-metal stents in Turkey.

Aims:

To evaluate bare-metal and drug-eluting stents used in the treatment of coronary artery disease from the perspective of the reimbursement institution with cost-effectiveness analysis.

Study Design:

Retrospective cost-effectiveness analysis.

Methods:

In our study, 329 patients diagnosed with coronary artery disease and treated with bare-metal or drug-eluting stents in the cardiology clinics of a public university hospital between January 1 and December 31, 2016 were investigated. Bare-metal and drug-eluting stents used in the treatment of coronary artery disease were evaluated retrospectively with cost-effectiveness analysis from the perspective of the reimbursement institution.

Results:

The cost of treatment with a bare-metal stent was 2,131.41 Turkish Liras, and the cost of treatment with a drug-eluting stent was 3,546.14 Turkish Liras; the Quality Adjusted Life Years value of treatment with a bare-metal stent was 0.8371, and the Quality Adjusted Life Years value of treatment with a drug-eluting stent was 0.8924. All these data were analyzed by decision tree. As a result of decision tree analysis, the weighted cost of treatment with a bare-metal stent was 2,340.71 Turkish Liras and weighted Quality Adjusted Life Years value was 0.8332; and the weighted cost of treatment with drug-eluting stent was 3,970.90 Turkish Liras and the weighted Quality Adjusted Life Years value of the treatment with drug-eluting stent was 0.8911. With these values, the additional cost-effectiveness ratio was calculated as 28,179.12 Turkish Liras per acquired Quality Adjusted Life Years. The additional cost-effectiveness ratio is in the first zone in the cost-effectiveness plane and below the very threshold of cost-effectiveness.

Conclusion:

In our study, it was concluded that drug-eluting stents are cost effective compared with bare-metal stents in the treatment of coronary artery disease. Considering the cost and effectiveness of the drug-eluting stent, it is thought that increasing reimbursement for this technology by the reimbursement agency would be beneficial for the service provider.

Clinical, humanistic, and economic outcomes between drug-eluting stent (DES) and bare metal stent (BMS): 18-month follow-up study

BACKGROUND

Percutaneous coronary intervention (PCI) is one of the most performed interventions for ischemic heart diseases. In Hong Kong, the total number of patient discharges and deaths for ischemic heart diseases in 2009 was 33,363, including 4,360 deaths. There are over 5,000 cases of PCI yearly. This study aimed to compare clinical, economic, and humanistic outcomes among patients receiving drug-eluting stent (DES) or bare metal stent (BMS) in Hong Kong.

METHODS

Patients who received stent implantation between September 15, 2009 and October 11, 2010 in Prince of Wales Hospital, Hong Kong, were recruited and followed for 18 months. Occurrence of major adverse cardiac events (cardiac death, non-fatal MI, TLR and TVR) was employed as the clinical outcome measurements. Improvement in quality-of-life by stent interventions was measured as quality-adjusted life-year (QALY). EQ-5D questionnaire was adopted to assess the QALY gained. Cost-utility analysis and cost-effectiveness analysis for BMS and DES were employed as the economic outcome measurement.

RESULTS

Six hundred and eighty-four patients (DES = 402; BMS = 282) were included. From 0-18 months, TLR rate (2.7% vs 3.5%, p = .549) and TVR rate (3.7% vs 6.4%, p = .111) were lower in the DES group, but without statistical significance. EQ VAS (71.06 ± 14.56 vs 71.07 ± 16.57, p = .998) and utility score (0.81 ± 0.17 vs 0.78 ± 0.16, p = .162) were comparable between DES and BMS group. Overall, the cost per QALY gained was HKD + 1,178,100 and ICER was HKD + 187,000 (1USD = 7.8 HKD).

CONCLUSIONS

No significant difference in TVR, TLR rates, EQ VAS, and utility score was found between the DES and BMS group. The higher cost of index procedure for the DES group was found to be partly offset by reduced cost of follow-up, offering cost-effectiveness in ACS patients, predominantly in STEMI patients. DES was recommended for STEMI patients.

MEDICAL DEVICE PRICES IN ECONOMIC EVALUATIONS

Objectives: Economic evaluations, although not formally used in purchasing decisions for medical devices in Canada, are still being conducted and published. The aim of this study was to examine the way that prices have been included in Canadian economic evaluations of medical devices.

Methods: We conducted a review of the economic concepts and implications of methods used for economic evaluations of the eleven most implanted medical devices from the Canadian perspective.

Results: We found Canadian economic studies for five of the eleven medical devices and identified nineteen Canadian studies. Overall, the device costs were important components of total procedure cost, with an average ratio of 44.1 %. Observational estimates of the device costs were obtained from buyers or sellers in 13 of the 19 studies. Although most of the devices last more than 1 year, standard costing methods for capital equipment was never used. In addition, only eight studies included a sensitivity analysis for the device cost. None of the sensitivity analyses were based on actual price distributions.

Conclusions: Economic evaluations are potentially important for policy making, but although they are being conducted, there is no standardized approach for incorporating medical device prices in economic analyses. Our review provides suggestions for improvements in how the prices are incorporated for economic evaluations of medical devices.

Stratification of coronary artery disease patients for revascularization procedure based on estimating adverse effects

Background

Percutaneous coronary intervention (PCI) is the most commonly performed treatment for coronary atherosclerosis. It is associated with a higher incidence of repeat revascularization procedures compared to coronary artery bypass grafting surgery. Recent results indicate that PCI is only cost-effective for a subset of patients. Estimating risks of treatment options would be an effort toward personalized treatment strategy for coronary atherosclerosis.

Methods

In this paper, we propose to model clinical knowledge about the treatment of coronary atherosclerosis to identify patient-subgroup-specific classifiers to predict the risk of adverse events of different treatment options. We constructed one model for each patient subgroup to account for subgroup-specific interpretation and availability of features and hierarchically aggregated these models to cover the entire data. In addition, we deviated from the current clinical workflow only for patients with high probability of benefiting from an alternative treatment, as suggested by this model. Consequently, we devised a two-stage test with optimized negative and positive predictive values as the main indicators of performance. Our analysis was based on 2,377 patients that underwent PCI. Performance was compared with a conventional classification model and the existing clinical practice by estimating effectiveness, safety, and costs for different endpoints (6 month angiographic restenosis, 12 and 36 month hazardous events).

Results

Compared to the current clinical practice, the proposed method achieved an estimated reduction in adverse effects by 25.0% (95% CI, 17.8 to 30.2) for hazardous events at 36 months and 31.2% (95% CI, 25.4 to 39.0) for hazardous events at 12 months. Estimated total savings per patient amounted to $693 and $794 at 12 and 36 months, respectively. The proposed subgroup-specific method outperformed conventional population wide regression: The median area under the receiver operating characteristic curve increased from 0.57 to 0.61 for prediction of angiographic restenosis and from 0.76 to 0.85 for prediction of hazardous events.

Conclusions

The results of this study demonstrated the efficacy of deployment of bare-metal stents and coronary artery bypass grafting surgery for subsets of patients. This is one effort towards development of personalized treatment strategies for patients with coronary atherosclerosis that could significantly impact associated treatment costs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12911-015-0131-0) contains supplementary material, which is available to authorized users.

The favorable price evolution between bare metal stents and drug eluting stents increases the cost effectiveness of drug eluting stents

AIMS

We aimed to assess the cost effectiveness of the sirolimus-eluting stent (SES) in diabetic and non-diabetic patients vs. bare metal stents (BMS).

METHODS

EVASTENT was a matched cohort registry of patients undergoing revascularization exclusively with SES; for each diabetic patient (db+) included, stratified according to single (SVD) or multiple (MVD) vessel disease, a non-diabetic patient (db-) was subsequently included. Efficacy, safety and cost data were obtained from the SES database, and then data from the BMS group were derived by using an original method of transition probabilities of events (Markov model and Monte Carlo simulations) if BMS had been implanted in the same patient, over a 3-year time period. Sensitivity analysis was performed by varying the price difference between BMS and SES from 2008 to 2012.

RESULTS

In this study, 1731 patients were included with 97% complete follow-up at 3-years. In 2008, compared to BMS the SES was cost effective only in MVD db+ (7494€ per avoided revascularization (PAR) vs. >10,000€ in other groups). In 2012, after a reduction in the price difference between SES and BMS, SES were cost effective in MVD db+ (-891), SVD db+ (3519), MVD db- (3050), and SVD db- (6329) patients. Otherwise, the cardiovascular mortality rate was higher (p<0.0001) in MVD db+ than in SVD db+, MVD db- and SVD db-.

CONCLUSION

The SES is now cost effective in diabetic and non-diabetic patients, after a favorable price evolution between drug eluting and bare metal stents.

Willingness to pay to eliminate the risk of restenosis following percutaneous coronary intervention: a contingent valuation

BACKGROUND

Percutaneous coronary intervention (PCI) remains limited by the risk of restenosis. Patients' perceptions of the health benefits and value of avoiding restenosis are incompletely known.

METHODS AND RESULTS

We used a contingent valuation approach to assess the willingness to pay (WTP) for a hypothetical treatment that eliminates the risk of restenosis among 270 PCI patients. Patients were provided with a scenario describing a baseline 10% or 20% probability of restenosis in the year following the procedure, which could lead to repeat PCI or, more rarely, bypass surgery, without any increase in mortality. Six different "take it or leave it" bids ($500, $1000, $1500, $2000, $2500, and $3000) and both risk levels were randomly assigned. Multiple logistic regression was used to identify independent predictors of a positive response to the WTP question. Using nonparametric methods, the median WTP to eliminate the risk of restenosis was estimated at $2802. As expected, higher income was independently associated with a higher probability of a positive response to the WTP question (odds ratio, 2.81; 95% CI, 1.32 to 5.97). Bids also were independently associated with the probability of being willing to pay, and this association followed a quadratic effect. Below $1500, bid had little impact on patient answers. However, as prices increased, the probability of being willing to pay started to decrease sharply.

CONCLUSION

The potential to eliminate the risk of restenosis, a benign complication, would have substantial value for patients undergoing PCI.

Drug-eluting stents: a study of international practice

OBJECTIVE

We aimed to analyze trends in drug-eluting stents (DES) use in four international health care and regulatory settings.

BACKGROUND

Accounts suggest a differential approach to DES internationally and recent reductions in use following reports of late stent thrombosis. Current studies of clinical practice are limited in their scope.

METHODS

Data were pooled from angioplasty registries in Alberta (Canada), Belgium, Mayo Clinic (Rochester, MN), and Scotland (UK) that have routinely recorded consecutive patients treated since 2003. Trend analysis was performed to examine variations in DES use over time and by clinical subgroup.

RESULTS

A total of 178,504 lesions treated between January 2003 and September 2007 were included. In the Mayo Clinic Registry, rapid adoption to a peak of 91% DES use for all lesions by late 2004 was observed. In contrast, Alberta and Scotland showed delayed adoption with lower peak DES use, respectively, 56% and 58% of lesions by early 2006. Adoption of DES in Belgium was more gradual and peak use of 35% lower than other registries. Reductions in DES use were seen in all data sets during 2006, although this varied in absolute and relative terms and by clinical subgroup.

CONCLUSION

Adoption and use of DES showed wide variation in four countries. The determinants of use are complex, and it is likely that nonclinical factors predominate. Recent reductions in use may be as a consequence of publicity and concerns regarding late stent thrombosis. The optimum application of DES in clinical practice is unclear and is reflected in the degree of international variation demonstrated.

Cost-effectiveness of drug-eluting stents in a US Medicare setting:a cost-utility analysis with 3-year clinical follow-up data

BACKGROUND

There is only limited information about cost-effectiveness of drug-eluting compared with bare metal stents (BMS) over a time horizon of more than 1 year.

METHODS AND RESULTS

We developed a Markov model based on clinical outcome data from a meta-analysis including 17 randomized controlled trials comparing drug-eluting versus BMS with a minimum follow-up of 1 (n = 8221) and a maximum follow-up of 3 years (n = 4105) in patients with chronic coronary artery disease. Costs were obtained as reimbursement rates for diagnosis related groups from the US Centers for Medicare and Medicaid Services. All costs and effects were discounted at 3% annually. All costs are reported in US dollars of the financial year 2007. The incremental effects are 0.002 (95% confidence interval −0.039 to 0.041) quality-adjusted life-years (QALYs) for the sirolimus- and −0.001 (−0.040 to 0.038) QALYs for the paclitaxel-eluting stents (PES). The incremental costs are $2790 for the sirolimus- and $3838 for the PES. The incremental cost-effectiveness ratio is >$1,000,000 per QALY for the sirolimus-eluting stent. PES are dominated by BMS (i.e., less effective and more costly). Among various sensitivity analyses performed, the model proved to be robust.

CONCLUSIONS

Our analysis from a US Medicare perspective suggests that drug-eluting stents are not cost-effective compared with BMS when implanted in unselected patients with symptomatic ischemic coronary artery disease.

Economic evaluation of drug-eluting stents compared to bare metal stents using a large prospective study in Ontario

Objectives:To determine the cost-effectiveness (CE) and cost-utility (CU) of drug-eluting stents (DES) compared to bare metal stents (BMS) in Ontario using a large prospective “real-world” cohort study and determine the extent to which results vary by patient risk subgroups.

Methods:A field evaluation was conducted based on all stent procedures in the province of Ontario between December 1, 2003, and March 31, 2005, with a minimum subject follow-up of 1 year. Effectiveness data from the study using a propensity-score matched cohort were combined with resource utilization and cost data and quality of life (QOL) data from the published literature in a decision analytic modeling framework to determine 2-year cost-effectiveness (cost per revascularization avoided) and cost-utility (cost per quality-adjusted life-year ([QALY] gained). Stochastic model parameter uncertainty was expressed using probability distributions and analyzed using a probabilistic model. Modeling assumptions were assessed using traditional deterministic sensitivity analysis.

Results:Significant differences in revascularization rates were found for patients with two or more high risk factors. Despite these differences, the CE and CU of DES remained high (e.g., $419,000 per QALY gained in the most favorable patient risk subgroup). In sensitivity analysis, the difference in cost between DES and BMS had an impact on the CE and CU results. For example, at a price differential of $500, the CU of DES was $20,000/QALY for one patient subgroup and DES was dominant (i.e., less costly and more effective) in another.

Conclusions:At current prices, the CE/CU of DES compared with BMS is high even in patient high risk subgroups. As the relative price of DES decrease, the value for money attractiveness of DES increases, especially for selected high risk patients.

Economic evaluation of drug-eluting stents: A systematic literature review and model-based cost–utility analysis

Objectives:The aim of this study was to systematically review economic analyses comparing drug-eluting stents (DES) to bare metal stents (BMS) in patients who undergo percutaneous coronary intervention to form an overall view about cost-effectiveness of DES and to construct a simple decision analysis model to evaluate the cost–utility of DES.

Methods:Electronic databases searched from January 2004 to January 2006 were Cochrane Database of Systematic Reviews; DARE, HTA, EED (NHS CRD); MEDLINE(R) In-Process, Other Non-Indexed Citations, MEDLINE(R). References of the papers identified were checked. We included randomized controlled trials (RCT) or model-based cost-effectiveness analyses comparing DES to BMS in patients with coronary artery disease. The methodological quality of the papers was assessed by Drummond's criteria. Baseline characteristics and results of the studies were extracted and data synthesized descriptively. A decision tree model was constructed to evaluate the cost–utility of DES in comparison to BMS, where health-related quality of life was measured by the 15D.

Results:We identified thirteen good-quality economic evaluations. In two of these based on RCTs, DES was found cost-effective. In six studies, it was concluded that DES might probably be a cost-effective strategy in some circumstances, but not as a single strategy, and four studies concluded that DES is not cost-effective. One study did not draw a clear conclusion. In our analysis, the overall incremental cost-effectiveness ratio was €98,827 per quality-adjusted life-years gained. Avoiding one revascularization with DES would cost €4,794, when revascularization with BMS costs €3,260.

Conclusions:The evidence is inconsistent of whether DES would be a cost-effective treatment compared with BMS in any healthcare system where evaluated. A marked restenosis risk reduction should be achieved before use of DES is justifiable at present prices. When considering adoption of a new health technology with a high incremental cost within a fixed budget, opportunity cost in terms of untreated patients should be seriously considered as a question of collective ethics.

Effect of hospital ownership status and payment structure on the adoption and use of drug-eluting stents for percutaneous coronary interventions

BACKGROUND

The impact of the use of drug-eluting stents in percutaneous coronary intervention (PCI) on cardiac care is still uncertain. We examined the influence of systemic factors, such as hospital ownership status, organizational characteristics and payment structure, on the use of drug-eluting stents in PCI and the effect on cardiac surgery volume.

METHODS

We conducted a cross-sectional analysis of drug-eluting stent use in 12 993 patients undergoing PCI with stenting (drug-eluting or bare-metal) and time-series regression analyses of the monthly number of cardiac surgery and PCI procedures performed using data collected from 1998 to 2004 at 13 public and private hospitals in the Emilia-Romagna region of Italy.

RESULTS

Public hospitals used drug-eluting stents more selectively than private hospitals, targeting the new device to patients at high risk of adverse events. The time-series regression analyses showed that the number of PCI procedures performed per year increased during this period, both in public (slope coefficient 36.4, 95% confidence interval [CI] 30.2 to 43.1) and private centres (slope coefficient 6.4, 95% CI 3.1 to 9.2 ). Concurrently, there was a reduction in the number of isolated coronary artery bypass graft (CABG) surgeries, although the degree of change was higher in public than in private hospitals (coefficient -16.1 v. -6.2 respectively ). The number of CABG procedures associated with valve surgery decreased in public hospitals (coefficient -5.0, 95% CI -6.1 to -3.8) but increased in private hospitals (coefficient 4.1, 95% CI 2.0 to 6.1).

INTERPRETATION

Public and private hospitals behaved differently in adopting drug-eluting stents and in using PCI with drug-eluting stents as a substitute for surgical revascularization.

The cost-effectiveness of drug-eluting stents: a systematic review

BACKGROUND

Drug-eluting stents have been seen as an attractive alternative to bare-metal stents for percutaneous coronary interventions (PCIs) because of the decreased need for revascularization. However, comparative clinical trials have shown no difference in patient outcomes, and drug-eluting stents are considerably more expensive than their bare-metal counterparts. We conducted a systematic review of all published comparative cost-effectiveness analyses to identify the factors contributing to the heterogeneity of their conclusions.

METHODS

We retrieved all articles published between Jan. 1, 2000, and July 31, 2006, in which the cost-effectiveness, from a third-party payer perspective, of drug-eluting stents was compared with that of bare-metal stents for PCI in unrestricted patient populations. Electronic databases, Web sites from health technology assessment groups and references of identified articles were searched. Our outcome variable was whether the study's conclusions favoured widespread use of drug-eluting stents, as assessed by 4 independent reviewers. Study characteristics such as quality, funding source, country and year of publication were extracted. Two-by-2 tables and Fisher's exact test were used to study the association between covariates and the outcome variable. A classification and regression tree (CART) model was used for multivariate analysis.

RESULTS

We identified 19 cost-effectiveness analyses. Ten were in favour of widespread use of drug-eluting stents, and 9 favoured more restrained use. Only 1 of 9 high-quality studies supported widespread use, as compared with 9 of 10 lower quality studies (p < 0.001). All of the 7 sponsored studies argued in favour of widespread use, as compared with 3 of the 12 studies without sponsorship (p = 0.003). Studies from the United States were more likely than those from other countries to endorse unlimited use (p = 0.032). A CART model with 2 covariates--study quality and sponsorship--provided the best fit (error rate 10.5%).

INTERPRETATION

Conclusions drawn by cost-effectiveness analyses of drug-eluting stents for PCI are associated with the study's quality, funding source and country of origin. Vigilance regarding these study characteristics is required when interpreting findings from cost-effectiveness analyses.