Cost-Utility Analysis of Mechanical Thrombectomy Using Stent Retrievers in Acute Ischemic Stroke

"Strokenomics": bending the cost curve in stroke care

OBJECTIVE

The mortality rates for stroke are decreasing, yet it remains a leading cause of disability and the principal neurological diagnosis in patients discharged to nursing homes. The societal and economic burdens of stroke are substantial, with the total annual health care costs of stroke expected to reach $240.7 billion by 2030. Mechanical thrombectomy has been shown to improve functional outcomes compared to medical therapy alone. Despite an incremental cost of $10,840 compared to medical therapy, the improvement in functional outcomes and decreased disability have contributed to the cost-effectiveness of the procedure. In this study the authors describe a physician-led device bundle purchase program implemented for the delivery of stroke care.

METHODS

The authors retrospectively reviewed the clinical and radiographic data and device-associated charges of 45 consecutive patients in whom a virtual "stroke bundle" model was used to purchase mechanical thrombectomy devices.

RESULTS

Use of the stroke bundle to purchase mechanical thrombectomy devices resulted in an average savings per case of $2900.93. Compared to the traditional model of charging for devices à la carte, this represented an average savings of 25.2% per case. The total amount of savings for these initial 45 cases was $130,542.00. Thrombolysis in Cerebral Infarction scale grade 2b or 3 recanalization occurred in 38 patients (84.4%) using these devices.

CONCLUSIONS

Purchasing devices through a bundled model resulted in substantial cost savings while maintaining the therapeutic efficacy of the procedure, further pushing the already beneficial long-term cost-benefit curve in favor of thrombectomy.

Economic challenges of using innovative medical devices in major public health pathologies: Example of acute ischemic stroke management by mechanical thrombectomy

BACKGROUND

Activity-based Funding can induce financial imbalances for health institutions if innovative medical devices (MD) used to perform acts are included in Diagnosis Related Groups (DRG) tariff. To be reimbursed in addition to the DRG tariff, innovative MD must have received a favorable evaluation by the French National Authority for Health (Haute Autorité de Santé) and be registered on the positive list. The aim of this study was to evaluate the expenses and incomes generated by each scenario (before and after the reimbursement of MD), and the financial reports. This study concerned the management of ischemic stroke by mechanical thrombectomy devices, in high-volume French hospital.

METHODS

All patients who have had an acute ischemic stroke and admitted to the interventional neuroradiology unit between January 2016 and December 2017 were included retrospectively in this monocentric study. They were divided into four subgroups based on the severity of the DRG. The cost study was carried out using the French National Cost Study Methodology adjusted for the duration of the stays and by micro-costing on MD.

RESULTS

A total of 267 patients were included. Over the study period, the average cost of the hospital stay was €10,492±6364 for a refund of €9838±6749 per patient. The acts performed became profitable once the MD were registered on the positive list (€-1017±3551 vs. €560±2671; P<0.05). Despite this reimbursement, this activity remained in deficit for DRG lowest severity (level 1) patients (€-492±1244). Specific MD used for mechanical thrombectomy represented 37% of the total cost of stay.

CONCLUSION

The time required to evaluate MD reimbursement files is too long compared to their development. As a result, practitioners are in difficulty to be able to carry out acts according to the consensual practices of their learned societies, without causing any financial deficit of their institutions.

Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

Background and Purpose- The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations in a single document for clinicians caring for adult patients with acute arterial ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 Acute Ischemic Stroke (AIS) Guidelines and are an update of the 2018 AIS Guidelines. Methods- Members of the writing group were appointed by the American Heart Association (AHA) Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. An update of the 2013 AIS Guidelines was originally published in January 2018. This guideline was approved by the AHA Science Advisory and Coordinating Committee and the AHA Executive Committee. In April 2018, a revision to these guidelines, deleting some recommendations, was published online by the AHA. The writing group was asked review the original document and revise if appropriate. In June 2018, the writing group submitted a document with minor changes and with inclusion of important newly published randomized controlled trials with >100 participants and clinical outcomes at least 90 days after AIS. The document was sent to 14 peer reviewers. The writing group evaluated the peer reviewers' comments and revised when appropriate. The current final document was approved by all members of the writing group except when relationships with industry precluded members from voting and by the governing bodies of the AHA. These guidelines use the American College of Cardiology/AHA 2015 Class of Recommendations and Level of Evidence and the new AHA guidelines format. Results- These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings. Conclusions- These guidelines provide general recommendations based on the currently available evidence to guide clinicians caring for adult patients with acute arterial ischemic stroke. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

Mortality reduction after thrombectomy for acute intracranial large vessel occlusion: meta-analysis of randomized trials

Background

Thrombectomy for patients with emergent large vessel occlusion (ELVO) is currently recognized as the standard of care for appropriately selected patients. As proven in several randomized clinical trials and meta-analyses, treatment with thrombectomy lowers rates of poor functional outcomes after ELVO, compared with standard medical management. However, combined mortality rates of the most recent, high-quality clinical trials have not been collectively assessed.

Objective

The goal of this study was to assess the combined mortality rates of patients with ELVO following thrombectomy using data from the most recent, high-quality clinical trials.

Methods

Meta-analysis was performed in clinical trials comparing thrombectomy and medical management for patients with anterior circulation ELVO. Cumulative rates of mortality (mRS 6) as well as mortality or severe disability (mRS 5-6) were calculated.

Results

Ten clinical trials fit the inclusion criteria, including PISTE, REVASCAT, DAWN, THRACE, SWIFT PRIME, ESCAPE, DEFUSE 3, THERAPY, EXTEND-IA, and MR CLEAN, with 2233 patients assessed for mortality alone and 2229 for mortality or severe disability. There was a significantly reduced risk of death with thrombectomy compared with standard medical care (14.9% vs 18.3%, P=0.03; RR 0.81, 95% CI 0.67 to 0.98), as well as a reduced risk of mortality or severe disability (mRS 5–6) in ELVO patients treated with thrombectomy (21.1% vs 30.5%, P<0.0001; RR 0.69, 95% CI 0.60 to 0.80).

Conclusions

Overall, these results suggest a lower risk of death, as well as death or severe disability, in patients with ELVO treated with thrombectomy compared with medical management alone.

Exploring the Cost-Effectiveness of Mechanical Thrombectomy Beyond 6 Hours Following Advanced Imaging in the United Kingdom

Supplemental Digital Content is available in the text.

In the United Kingdom, mechanical thrombectomy (MT) for acute ischemic stroke patients assessed beyond 6 hours from symptom onset will be commissioned up to 12 hours provided that advanced imaging (AdvImg) demonstrates salvageable brain tissue. While the accuracy of AdvImg differs across technologies, evidence is limited regarding the proportion of patients who would benefit from late MT. We compared the cost-effectiveness of 2 care pathways: (1) MT within and beyond 6 hours based on AdvImg selection versus (2) MT only within 6 hours based on conventional imaging selection. The impact of varying AdvImg accuracy and prior probability for acute ischemic stroke patients to benefit from late MT was assessed.

Mechanical thrombectomy in patients with acute ischemic stroke: A cost-effectiveness and value of implementation analysis

Background

Recent clinical trials have demonstrated the efficacy of mechanical thrombectomy in acute ischemic stroke.

Aims

To determine the cost-effectiveness, value of future research, and value of implementation of mechanical thrombectomy.

Methods

Using UK clinical and cost data from the Pragmatic Ischemic Stroke Thrombectomy Evaluation (PISTE) trial, we estimated the cost-effectiveness of mechanical thrombectomy over time horizons of 90-days and lifetime, based on a decision-analytic model, using all existing evidence. We performed a meta-analysis of seven clinical trials to estimate treatment effects. We used sensitivity analysis to address uncertainty. Value of implementation analysis was used to estimate the potential value of additional implementation activities to support routine delivery of mechanical thrombectomy.

Results

Over the trial period (90 days), compared with best medical care alone, mechanical thrombectomy incurred an incremental cost of £5207 and 0.025 gain in QALY (incremental cost-effectiveness ratio (ICER) £205,279), which would not be considered cost-effective. However, mechanical thrombectomy was shown to be cost-effective over a lifetime horizon, with an ICER of £3466 per QALY gained. The expected value of perfect information per patient eligible for mechanical thrombectomy in the UK is estimated at £3178. The expected value of full implementation of mechanical thrombectomy is estimated at £1.3 billion over five years.

Conclusion

Mechanical thrombectomy was cost-effective compared with best medical care alone over a patient’s lifetime. On the assumption of 30% implementation being achieved throughout the UK healthcare system, we estimate that the population health benefits obtained from this treatment are greater than the cost of implementation.

Trial registration

NCT01745692.

Technical considerations of multi-parametric tissue outcome prediction methods in acute ischemic stroke patients

Decisions regarding acute stroke treatment rely heavily on imaging, but interpretation can be difficult for physicians. Machine learning methods can assist clinicians by providing tissue outcome predictions for different treatment approaches based on acute multi-parametric imaging. To produce such clinically viable machine learning models, factors such as classifier choice, data normalization, and data balancing must be considered. This study gives comprehensive consideration to these factors by comparing the agreement of voxel-based tissue outcome predictions using acute imaging and clinical parameters with manual lesion segmentations derived from follow-up imaging. This study considers random decision forest, generalized linear model, and k-nearest-neighbor machine learning classifiers in conjunction with three data normalization approaches (non-normalized, relative to contralateral hemisphere, and relative to contralateral VOI), and two data balancing strategies (full dataset and stratified subsampling). These classifier settings were evaluated based on 90 MRI datasets from acute ischemic stroke patients. Distinction was made between patients recanalized using intraarterial and intravenous methods, as well as those without successful recanalization. For primary quantitative comparison, the Dice metric was computed for each voxel-based tissue outcome prediction and its corresponding follow-up lesion segmentation. It was found that the random forest classifier outperformed the generalized linear model and the k-nearest-neighbor classifier, that normalization did not improve the Dice score of the lesion outcome predictions, and that the models generated lesion outcome predictions with higher Dice scores when trained with balanced datasets. No significant difference was found between the treatment groups (intraarterial vs intravenous) regarding the Dice score of the tissue outcome predictions.

Barriers and Facilitators to Model Replication Within Health Economics

BACKGROUND

Model replication is important because it enables researchers to check research integrity and transparency and, potentially, to inform the model conceptualization process when developing a new or updated model.

OBJECTIVE

The aim of this study was to evaluate the replicability of published decision analytic models and to identify the barriers and facilitators to replication.

METHODS

Replication attempts of 5 published economic modeling studies were made. The replications were conducted using only publicly available information within the manuscripts and supplementary materials. The replicator attempted to reproduce the key results detailed in the paper, for example, the total cost, total outcomes, and if applicable, incremental cost-effectiveness ratio reported. Although a replication attempt was not explicitly defined as a success or failure, the replicated results were compared for percentage difference to the original results.

RESULTS

In conducting the replication attempts, common barriers and facilitators emerged. For most case studies, the replicator needed to make additional assumptions when recreating the model. This was often exacerbated by conflicting information being presented in the text and the tables. Across the case studies, the variation between original and replicated results ranged from -4.54% to 108.00% for costs and -3.81% to 0.40% for outcomes.

CONCLUSION

This study demonstrates that although models may appear to be comprehensively reported, it is often not enough to facilitate a precise replication. Further work is needed to understand how to improve model transparency and in turn increase the chances of replication, thus ensuring future usability.

One-Year Healthcare Utilization for Patients That Received Endovascular Treatment Compared With Control

Background and Purpose- Endovascular therapy has been shown to be highly efficacious based on 90-day modified Rankin Scale score. We examined actual daily healthcare utilization from stroke onset to 1 year afterward from the ESCAPE trial (Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Time) and registry data. Methods- We examined patients from Alberta, Canada, that was enrolled into the ESCAPE trial and the Quality Improvement and Clinical Research registry in the 2016/2017 fiscal year. Through data linkages to several administrative data sets, the daily location of each patient was assessed in various healthcare settings. Results- A total of 286 patients were analyzed, 52 patients were in the treatment arm, and 47 patients were in the control arm of the ESCAPE trial while 187 patients received endovascular therapy as usual care (2016/2017 fiscal year). The odds of a patient being out of a healthcare setting over 1 year was significantly higher when they received endovascular therapy: 3.46 (1.68-7.30) in ESCAPE trial patients and 2.00 (1.08-3.75) in the Quality Improvement And Clinical Research patients. Conclusions- Endovascular therapy significantly reduces healthcare utilization up to 1 year after a stroke.

Pre-thrombectomy intravenous thrombolytics are associated with increased hospital bills without improved outcomes compared with mechanical thrombectomy alone

OBJECTIVE

To investigate whether significant differences exist in hospital bills and patient outcomes between patients who undergo endovascular thrombectomy (EVT) alone and those who undergo EVT with pretreatment intravenous tissue plasminogen activator (IV tPA).

METHODS

We retrospectively grouped patients in an EVT database into those who underwent EVT alone and those who underwent EVT with pretreatment IV tPA (EVT+IV tPA). Hospital encounter charges (obtained via the hospital's charge capture process), final patient bills (ie, negotiated final bills as per insurance/Medicare rates), demographic information, existing comorbidities, admission and discharge National Institutes of Health Stroke Scale (NIHSS) score, and functional independence data (modified Rankin Scale score 0-2) were collected. Univariate and multivariate statistical analyses were performed.

RESULTS

Of a total of 254 patients, 96 (37.8%) underwent EVT+IV tPA. Median NIHSS score at admission was significantly higher in the EVT+IV tPA group than in the EVT group (p=0.006). After adjusting for NIHSS admission score, patient bills and encounter charges in the EVT+IV tPA group were still found to be $3861.64 (95% CI $658.84 to $7064.45, p=0.02) and $158 071.29 (95% CI $134 641.50 to $181 501.08, p < 0.001) greater than in the EVT only group respectively. The EVT+IV tPA group had a higher complication rate of intracranial hemorrhage (ICH) (p=0.005). The EVT and EVT+IV tPA groups did not differ significantly in median discharge NIHSS score (p=0.56), functional independence rate at 90 days (p=0.96), or average length of hospital stay (p=0.21).

CONCLUSION

Patients treated with EVT+IV tPA have greater hospital encounter charges and final hospital bills as well as higher rates of ICH than patients who undergo treatment with EVT only.

National Institutes of Health Stroke Scale, modified Rankin Scale, and modified Thrombolysis in Cerebral Infarction as autonomy predictive tools for stroke patients

Whereas mortality from ischemic stroke is decreasing in all age groups, the prevalence of stroke continues to increase. Its increasing incidence in the younger population adds to the large number of survivors who will live many years with their disabilities related to stroke. Thus, the objectives of this study are to determine the National Institutes of Health Stroke Scale (NIHSS), the modified Rankin Scale (mRS), and the modified Thrombolysis in Cerebral Infarction (mTICI) as adequate prognostic functionality tools for stroke patients and to analyze the relation between stroke and rehabilitation. This study involved a systematic review. We obtained articles found on Google Scholar and MEDLINE and published from January 2008 to May 2018. The functionality of the patient after a stroke is associated with the likelihood of a hospital readmission, which should be taken into account during the diagnosis. Patients with poor functionality at discharge are also more likely to need long-term care and intensive rehabilitation plans. The severity of the initial stroke is a primary determinant of the clinical outcome. The NIHSS, mRS, and mTICI appear to be predictive tools of the functionality of the patient with ischemic stroke, especially in the acute phase. Rehabilitation demonstrates better results in reducing disability and greater participation of affected people.

Cost-utility analysis of mechanical thrombectomy between 6 and 24 hours in acute ischemic stroke

Background

Recently, two randomized controlled trials demonstrated the benefit of mechanical thrombectomy performed between 6 and 24 h in acute ischemic stroke. The current economic evidence is supporting the intervention only within 6 h, but extended thrombectomy treatment times may result in better long-term outcomes for a larger cohort of patients.

Aims

We compared the cost-utility of mechanical thrombectomy in addition to medical treatment versus medical treatment alone performed beyond 6 h from stroke onset in the UK National Health Service (NHS).

Methods

A cost-utility analysis of mechanical thrombectomy compared to medical treatment was performed using a Markov model that estimates expected costs and quality-adjusted life years (QALYs) over a 20-year time horizon. We present the results of three models using the data from the DEFUSE 3 and DAWN trials and evidence from published sources.

Results

Over a 20-year period, the incremental cost per QALY of mechanical thrombectomy was $1564 (£1219) when performed after 12 h from onset, $5253 (£4096) after 16 h and $3712 (£2894) after 24 h. The probabilistic sensitivity analysis demonstrated that thrombectomy had a 99.9% probability of being cost-effective at the minimum willingness to pay for a QALY commonly used in the UK.

Conclusions

The results of this study demonstrate that performing mechanical thrombectomy up to 24 h from acute ischemic stroke symptom onset is still cost-effective, suggesting that this intervention should be implemented by the NHS on the basis of improvement in quality of life as well as economic grounds.

Burden of large vessel occlusion stroke and the service gap of thrombectomy: A population-based study using a territory-wide public hospital system registry

Background

Ischemic stroke due to large vessel occlusion can be effectively treated with thrombectomy but access to this treatment is limited in many parts of the world. Local incidence of large vessel occlusion is critical in determining the development of thrombectomy service, but reliable data from Asian countries are lacking.

Aims

We performed a population-based study to estimate the burden of large vessel occlusion and the service gap for thrombectomy in Hong Kong.

Methods

All acute ischemic stroke patients admitted in 2016 to the public healthcare system, which provided 90% of the emergency healthcare in the city, was identified from the Hong Kong Hospital Authority’s central electronic database. The diagnosis of large vessel occlusion was retrospectively verified by two independent cerebrovascular specialists in a randomly sampled cohort based on clinical and neuroimaging data. The incidence of large vessel occlusion in the population was estimated through weighting the sample results and compared with the thrombectomy data in the same period.

Results

There were 6859 acute ischemic stroke patients treated in the public health system in 2016. Amongst the 300 patients randomly sampled according to diagnosis coding, 130 suffered from anterior circulation large vessel occlusion. This translated to 918 patients (95% CI 653–1180) and 13.3% of all ischemic stroke patients. The estimated incidence of anterior circulation large vessel occlusion was 12.5 per 100,000 persons per year (95% CI 11.7–13.4). Large vessel occlusion stroke patients were more commonly female than male (67.4% vs. 31.6%, p = 0.003), and were older than non-large vessel occlusion stroke patients (mean of 80.5 years vs. 71.4 years, p = < 0.001). They also had higher 30-day mortality rate (31.1% vs. 4.6%, p = < 0.001), and longer hospital stay (mean 38.6 vs. 21.1 days, p = 0.003) than non-large vessel occlusion stroke. In the same period, 83 thrombectomies for large vessel occlusion were performed, representing 9.1% of the estimated large vessel occlusion incidence.

Conclusion

The estimated incidence of anterior circulation large vessel occlusion in the Hong Kong Chinese population is lower than that in the West. There is however a substantial service gap for endovascular thrombectomy with less than 10% of large vessel occlusion patients receiving thrombectomy.

Cost-effectiveness analysis of mechanical thrombectomy plus tissue-type plasminogen activator compared with tissue-type plasminogen activator alone for acute ischemic stroke in France

BACKGROUND AND PURPOSE

Recent studies demonstrated the benefit of mechanical thrombectomy (MT) plus intravenous tissue-type plasminogen activator (IV-tPA) (MT-IV-tPA) in acute ischemic stroke. This study aimed to estimate the cost-utility of MT-IV-tPA compared with IV-tPA alone from the perspective of the French National Health Insurance.

METHODS

We developed a decision tree for the first 3 months after stroke onset and a Markov model until 10 years post-stroke. The health states of the Markov model were according to the modified Rankin Scale (mRS): independent (mRS=0-2), dependent (mRS=3-5), dead (mRS=6). Recurrent stroke was the fourth health stage of our model. We conducted systematic literature reviews and meta-analyses to estimate the cost and utility of each health state, and the transition probabilities between health states. A microcosting study was conducted to estimate the cost of MT. We estimated the incremental cost-effectiveness ratio of MT-IV-tPA and conducted a probabilistic analysis in order to estimate the probability that MT-IV-tPA is cost-effective compared to IV-tPA, the expected value of perfect information (EVPI), and the expected value of partial perfect information (EVPPI), given the uncertainty surrounding the value of our model's parameters.

RESULTS

The total mean (standard deviation (SD) cost of MT was €6708.9 (2357.0). The incremental cost-effectiveness ratio (ICER) of the strategy using IV-tPA combined to MT costs was €14,715 per QALY gained as compared to a strategy using IV-tPA alone. The probabilistic analysis showed that the probability of MT-IV-TPA being cost-effective was 85.4% at threshold willingness-to-pay of €30,000 per QALY gained, reaching 98% at €50,000 per QALY gained.

CONCLUSION

Although there is no universally accepted willingness-to-pay threshold in France, our analysis suggest that MT combined to IV-tPA can be considered a cost-effective treatment compared with IV-tPA alone.

Acute ischaemic stroke: a systematic review of the cost-effectiveness of emergency endovascular therapy using mechanical thrombectomy

PURPOSE

Although good evidence exists regarding the clinical effectiveness of mechanical thrombectomy for people with acute ischaemic stroke, cost-effectiveness should also be considered. The aim of this study was to systematically review the evidence of cost-effectiveness of emergency endovascular therapy using mechanical thrombectomy in the management of acute ischaemic stroke.

METHODS

The search was carried out in PubMed, EMBASE, Cochrane Library, and a grey literature search. Studies were included if they compared the costs and consequences of mechanical thrombectomy added to usual medical care compared to usual care alone for people with acute ischaemic stroke in the anterior and/or posterior region. Study quality was assessed using two appraisal tools tailored to economic evaluations.

FINDINGS

Thirteen studies were identified including twelve cost-utility analyses and one cost-benefit analysis. Studies could be dichotomised into those that evaluated first-generation (n = 4) and second-generation (n = 9) mechanical thrombectomy devices. Six studies had low applicability, six had moderate applicability, and one had high applicability to other settings. All cost-utility studies reported incremental cost-effectiveness ratios that would be considered cost-effective under typical willingness-to-pay thresholds.

CONCLUSIONS

If the outcomes of the trials underpinning the evidence of clinical effectiveness can be replicated, then mechanical thrombectomy is likely to be cost-effective by typical willingness-to-pay thresholds. This finding holds under the assumption that no investment is required to develop stroke centres to the standard required to provide a safe emergency endovascular service and that additional expenditure on timely patient transport is not required.

Disability Adjusted Life Years due to Ischaemic Stroke Preventable by Real-Time Stroke Detection-A Cost-Utility Analysis of Hypothetical Stroke Detection Devices

Background: Ischaemic stroke remains a significant contributor to permanent disability world-wide. Therapeutic interventions for acute ischaemic stroke (AIS) are available, but need to be administered early after symptom onset in order to be effective. Currently, one of the main factors responsible for poor clinical outcome is an unnecessary long time between symptom onset and arrival at a hospital (pre-hospital delay). In the future, technological devices with the capability of real-time detection of AIS may become available. The health economic implications of such devices have not been explored. Methods: We developed a novel probabilistic model to estimate the maximally allowable annual costs of different hypothetical real-time AIS detection devices in different populations given currently accepted willingness-to-pay thresholds. Distributions of model parameters were extracted from the literature. Effectiveness of the intervention was quantified as reduction in disability-adjusted life-years associated with faster access to thrombolysis and mechanical thrombectomy. Incremental costs were calculated from a societal perspective including acute treatment costs and long-term costs for nursing care, home help, and loss of production. The impact of individual model parameters was explored in one-way and multi-way sensitivity analyses. Results: The model yields significantly shorter prehospital delays and a higher proportion of acute ischaemic patients that fulfill the time-based eligibility criteria for thrombolysis or mechanical thrombectomy in the scenario with a real-time stroke detection device as compared to the control scenario. Depending on the sociodemographic and geographic characteristics of the study population and operating characteristics of the device, the maximally allowable annual cost for the device to operate in a cost-effective manner assuming a willingness-to-pay threshold of GBP 30.000 ranges from GBP 22.00 to GBP 9,952.00. Considering the results of multiway sensitivity analyses, the upper bound increases to GBP 29,449.10 in the subgroup of young patients with a very high annual risk of ischaemic stroke (50 years/20% annual risk). Conclusion: Data from probabilistic modeling suggest that real-time AIS detection devices can be expected to be cost-effective only for a small group of highly selected individuals.

Quality and resource efficiency in hospital service provision: A geoadditive stochastic frontier analysis of stroke quality of care in Germany

We specify a Bayesian, geoadditive Stochastic Frontier Analysis (SFA) model to assess hospital performance along the dimensions of resources and quality of stroke care in German hospitals. With 1,100 annual observations and data from 2006 to 2013 and risk-adjusted patient volume as output, we introduce a production function that captures quality, resource inputs, hospital inefficiency determinants and spatial patterns of inefficiencies. With high relevance for hospital management and health system regulators, we identify performance improvement mechanisms by considering marginal effects for the average hospital. Specialization and certification can substantially reduce mortality. Regional and hospital-level concentration can improve quality and resource efficiency. Finally, our results demonstrate a trade-off between quality improvement and resource reduction and substantial regional variation in efficiency.

Cost-effectiveness analysis of mechanical thrombectomy with stent retriever in the treatment of acute ischemic stroke in Italy

BACKGROUND

Stroke has a significant disease burden in terms of acute and long-term disability in Italy and throughout the world. Endovascular treatments for the management of a stroke event have been coupled in the past years with the possibility to mechanically remove the occlusion by means of specially designed thrombectomy devices, and their exclusive use showed levels of effectiveness in line with those of the existing pharmacological treatments.

OBJECTIVE

To assess the cost-effectiveness of mechanical thrombectomy (MT) with the Solitaire Revascularization Device (stent retriever) for the treatment of acute ischemic stroke (AIS) in patients with large vessel occlusions (LVOs), comparing MT plus intravenous tissue plasminogen activation (MT plus IV t-PA) vs IV t-PA alone, in Italy.

METHODS

A Markov model was used to simulate costs and benefits of MT plus IV t-PA and IV t-PA alone over a 5-year time horizon and considering the perspective of the Italian National Health Service (NHS). Results are reported in terms of Incremental Cost Effectiveness Ratio (ICER). Deterministic and probabilistic sensitivity analyses are carried out in order to test the robustness of the results.

RESULTS

Total costs of MT plus IV t-PA and IV t-PA alone are equal to €31,798 and €34,855, respectively. The MT allows incremental QALYs for 0.77, determining a dominant ICER. The utilities associated to the mRS health states are the parameters with the highest impact on the results. Multiway sensitivity analyses determined a 90% probability of dominance.

CONCLUSIONS

MT plus IV t-PA for AIS patients with LVO is cost-effective from year 1 through year 3, and cost-saving from year 4 onward in the Italian context, achieving better results, both in terms of efficacy and in terms of resource consumption.

Cost-effectiveness of mechanical thrombectomy for acute ischemic stroke: an Australian payer perspective

AIMS

The goal of this study was to assess the cost-effectiveness of mechanical thrombectomy (MT) for acute ischemic stroke (AIS) from an Australian payer perspective.

METHODS

This study used a Markov model that employed a life-time time horizon, modeling patients from symptom onset of stroke until end of life. Clinical efficacy and safety data were taken from an individual patient level data (IPD) meta-analysis of clinical studies. The treatment effect of MT compared to usual care was measured by changes in modified Rankin Score (mRS). Post-treatment mRS scores were used to determine short- and long-term stroke care costs. Treatment costs were modeled, with health state utility values determined by literature review. All analyses were conducted using Microsoft Excel.

RESULTS

In comparison to usual care, MT is associated with higher costs ($10,666 per patient) and additional quality-adjusted life years (QALYs) (0.8281 per patient), resulting in an incremental cost per QALY of $12,880. Sensitivity analyses demonstrated the reliability of the base case results across a range of assumptions. The higher cost associated with MT is, to an extent, offset by the cost savings resulting from lower stroke care costs due to improved patient outcomes. The life-time cost savings in terms of stroke care costs are estimated to be more than $8,000 per patient for patients who had received MT in combination with usual care.

LIMITATIONS

Stroke care costs based on patient disability/functional level were not available and were derived. As a consequence, long-term care costs for patients with poorer outcomes may be under-estimated. Patient outcomes at 90 days were extrapolated to a lifetime horizon, but this approach was supported by long-term evidence on stroke survival.

CONCLUSIONS

Mechanical thrombectomy is a cost-effective treatment option for AIS, with clinical benefits translating to short- and long-term cost benefits. This analysis supports rapid update of stroke care pathways to incorporate this therapy as a treatment option.

Thrombectomy for Acute Ischemic Stroke: Recent Insights and Future Directions

PURPOSE OF REVIEW

Mechanical thrombectomy has become the standard of care for acute ischemic stroke with proximal large vessel occlusions (LVO). This article reviews recent research relating to thrombectomy.

RECENT FINDINGS

Thrombectomy for anterior circulation stroke with proximal LVO was first shown to be highly efficacious within 6 h of stroke onset, but "late-window" trials have further demonstrated efficacy until 24-h postonset in select patients with salvageable tissue. However, the concept of "time is brain" remains critical. Thrombectomy trials have further stimulated worldwide efforts to develop systems of care for rapid treatment of eligible patients. Thrombectomy is cost-effective and likely to have long-term efficacy for both disability and mortality outcomes. Thrombectomy is a highly efficacious acute stroke therapy. Enduring uncertainties include efficacy in patients with premorbid disability, posterior circulation, or more distal occlusions; use of bridging thrombolysis; and optimal techniques to achieve consistent revascularization and address tandem occlusions or stenoses.

Systematic review of health economic studies in cranial neurosurgery

OBJECTIVE As the cost of health care continues to increase, there is a growing emphasis on evaluating the relative economic value of treatment options to guide resource allocation. The objective of this systematic review was to evaluate the current evidence regarding the cost-effectiveness of cranial neurosurgery procedures. METHODS The authors performed a systematic review of the literature using PubMed, EMBASE, and the Cochrane Library, focusing on themes of economic evaluation and cranial neurosurgery following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Included studies were publications of cost-effectiveness analysis or cost-utility analysis between 1995 and 2017 in which health utility outcomes in life years (LYs), quality-adjusted life years (QALYs), or disability-adjusted life years (DALYs) were used. Three independent reviewers conducted the study appraisal, data abstraction, and quality assessment, with differences resolved by consensus discussion. RESULTS In total, 3485 citations were reviewed, with 53 studies meeting the inclusion criteria. Of those, 34 studies were published in the last 5 years. The most common subspecialty focus was cerebrovascular (32%), followed by neurooncology (26%) and functional neurosurgery (24%). Twenty-eight (53%) studies, using a willingness to pay threshold of US$50,000 per QALY or LY, found a specific surgical treatment to be cost-effective. In addition, there were 11 (21%) studies that found a specific surgical option to be economically dominant (both cost saving and having superior outcome), including endovascular thrombectomy for acute ischemic stroke, epilepsy surgery for drug-refractory epilepsy, and endoscopic pituitary tumor resection. CONCLUSIONS There is an increasing number of cost-effectiveness studies in cranial neurosurgery, especially within the last 5 years. Although there are numerous procedures, such as endovascular thrombectomy for acute ischemic stroke, that have been conclusively proven to be cost-effective, there remain promising interventions in current practice that have yet to meet cost-effectiveness thresholds.

Cost-Effectiveness of Patent Foramen Ovale Closure Versus Medical Therapy for Secondary Stroke Prevention

BACKGROUND AND PURPOSE

Percutaneous transcatheter closure of patent foramen ovale (PFO closure) plus antiplatelet therapy has been shown to reduce the risk of recurrent stroke compared with medical therapy alone in carefully selected patients after cryptogenic stroke presumed to be from paradoxical embolism. Our objective was to determine the cost-effectiveness of PFO closure after cryptogenic stroke compared with conservative medical management from a US healthcare payer perspective.

METHODS

A decision analytic Markov model estimated the 15-year cost and outcomes associated with the additional benefit of PFO closure compared with medical management alone. Model inputs were obtained from published literature, national databases, and a meta-analysis of 5 published randomized clinical trials on PFO closure. Health outcomes were measured in quality-adjusted life years (QALY). Cost-effectiveness used the incremental cost per QALY gained, whereas the net monetary benefit assumed a willingness to pay of $150 000/QALY. One-way and probabilistic sensitivity analyses estimated the uncertainty of model results.

RESULTS

At 15 years, PFO closure compared with medical therapy alone improved QALY by 0.33 at a cost saving of $3568, representing an incremental net monetary benefit of $52 761 (95% interval -$8284 to $158 910). When the meta-analysis hazard ratio for stroke was increased to the 95% interval's upper bound of 0.77, one-way sensitivity analyses suggested that PFO closure's cost-effectiveness was $458 558 per additional QALY. Probabilistic sensitivity analysis suggested cost-effectiveness in 90% of simulation runs.

CONCLUSIONS

PFO closure for cryptogenic strokes in the right setting is cost-effective, producing benefit in QALYs gained and potential cost savings. However, patient selection remains vitally important as marginal declines in treatment effectiveness can dramatically affect cost-effectiveness.

Cost-effectiveness analysis of tissue plasminogen activator in acute ischemic stroke in Iran

AIMS

Tissue plasminogen activator (tPA) is used to treat acute ischemic stroke up to 4.5 h after symptom onset. Its cost-effectiveness in developing countries is not specified yet. This study aimed to study cost-effectiveness of tPA in Iran.

METHODS

This is a cost-effectiveness analysis from the perspective of the third party payer to compare IV tPA with no tPA of ischemic stroke. A Markov model with a lifetime horizon was used to analyze the costs and outcomes. Cost data were extracted from the 94 patients admitted in two hospitals in Iran. All costs were calculated based on US dollars in 2016. Quality-adjusted life years (QALY) were extracted from previously published literature. Cost-effectiveness was determined by calculating ICER by TreeAge Pro 2011 software.

RESULTS

Lifetime costs of no tPA strategy were higher than tPA ($10,718 in the no tPA group compared with $8,796 in the tPA group). The tPA arm gained 0.20 QALY compared with no tPA. ICER was $8,471 per QALY. ICER value suggests that tPA is cost-effective compared with no tPA.

LIMITATIONS

The limitations of the present study are the reliance on calculated QALY value of other countries and difficulty in accessing patients treated with tPA.

CONCLUSIONS

The balance of hospitalization and rehabilitation costs and QALYs support the conclusion that treatment with intravenous tPA in the 4.5-h time window is cost-effective from the perspectives of the third party payer and inclusion of tPA in the insurance benefit package being reasonable.

Cost-effectiveness of mechanical thrombectomy within 6 hours of acute ischaemic stroke in China

OBJECTIVES

Endovascular mechanical thrombectomy is an effective but expensive therapy for acute ischaemic stroke with proximal anterior circulation occlusion. This study aimed to determine the cost-effectiveness of mechanical thrombectomy in China, which is the largest developing country.

DESIGN

A combination of decision tree and Markov model was developed. Outcome and cost data were derived from the published literature and claims database. The efficacy data were derived from the meta-analyses of nine trials. One-way and probabilistic sensitivity analyses were performed in order to assess the uncertainty of the results.

SETTING

Hospitals in China.

PARTICIPANTS

The patients with acute ischaemic stroke caused by proximal anterior circulation occlusion within 6 hours.

INTERVENTIONS

Mechanical thrombectomy within 6 hours with intravenous tissue plasminogen activator (tPA) treatment within 4.5 hours versus intravenous tPA treatment alone.

OUTCOME MEASURES

The benefit conferred by the treatment was assessed by estimating the cost per quality-adjusted life-year (QALY) gained in the long term (30 years).

RESULTS

The addition of mechanical thrombectomy to intravenous tPA treatment compared with standard treatment alone yielded a lifetime gain of 0.794 QALYs at an additional cost of CNY 50 000 (US$7700), resulting in a cost of CNY 63 010 (US$9690) per QALY gained. The probabilistic sensitivity analysis indicated that mechanical thrombectomy was cost-effective in 99.9% of the simulation runs at a willingness-to-pay threshold of CNY 125 700 (US$19 300) per QALY.

CONCLUSIONS

Mechanical thrombectomy for acute ischaemic stroke caused by proximal anterior circulation occlusion within 6 hours was cost-effective in China. The data may be used as a reference with regard to medical resources allocation for stroke treatment in low-income and middle-income countries as well as in the remote areas in the developed countries.

2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations for clinicians caring for adult patients with acute arterial ischemic stroke in a single document. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 guidelines and subsequent updates.

METHODS

Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. The members of the writing group unanimously approved all recommendations except when relations with industry precluded members voting. Prerelease review of the draft guideline was performed by 4 expert peer reviewers and by the members of the Stroke Council's Scientific Statements Oversight Committee and Stroke Council Leadership Committee. These guidelines use the American College of Cardiology/American Heart Association 2015 Class of Recommendations and Levels of Evidence and the new American Heart Association guidelines format.

RESULTS

These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings.

CONCLUSIONS

These guidelines are based on the best evidence currently available. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

ESCAPE to Reality, Post-Trial Outcomes in an ESCAPE Centre: A Retrospective Case-Control Study

INTRODUCTION

The Royal Victoria Hospital, Belfast provides the regional neuroendovascular service for Northern Ireland and was an enrolling centre for the ESCAPE endovascular stroke trial. Our aim was to assess outcomes for patients presenting with acute stroke following discontinuation of trial enrolment at our centre.

METHODS

We collected data on all patients presenting with acute stoke between Nov-1st-2014 and Oct-31st-2015 who received endovascular treatment or received IV thrombolysis (IV-tPA) alone. ESCAPE eligibility of each patient was assessed. Primary outcome was modified Rankin Score (mRS) at 3 months.

RESULTS

129 patients presented with acute stoke symptoms during the time period; 56/129 (43.4%) patients in the intervention group and 73/129 (56.5%) patients in the control group. In the interventional group, 42/56 (75%) were considered ESCAPE eligible and 14/56 (25%) were considered ESCAPE ineligible. 30/42 (71.4%) ESCAPE eligible patients had a positive functional outcome at 3 months compared to 9/14 (64.2%) ESCAPE ineligible patients. In the control group, 37 (50.7%) had identifiable thrombotic occlusion and 13/37 (35.1%) were considered eligible for intervention. 4/13 (30.8%) achieved functional independence (mRS<3) at 3 months.There was a statistically significant difference in functional independence in those who underwent endovascular therapy compared to the control group (p= 0.04).

CONCLUSION

ESCAPE eligible patients in our centre had favourable outcome rates superior to the published trial data. ESCAPE ineligible patients tended to do slightly less well, but still better than the favourable outcome rates achieved with IVtPA alone. There is potentially a wide discordance between the threshold for futility and trial eligibility criteria when considering endovascular treatment for acute ischaemic stroke.

Value-based procurement of prostheses for total knee replacement

Cost-effectiveness evaluations concerning devices for total knee arthroplasty (TKA) have little impact on real-life management of these devices. This study explored how pharmacoeconomic models can inform the procurement of TKA devices to improve their value for money. Our study included three phases: i) literature search for data of outcome, cost, and device type in TKA; ii) development of a Markov model predicting costs, QALYs, and net monetary benefit (NMB); iii) simulation of tenders aimed at value-based device procurement. Phases 1 and 2 were managed by selecting a single study as the source of data for our analysis. In Phase 3, each TKA device was associated with its values of NMB, and the tender scores were estimated. Finally, the ranking of each device in the simulated tender was determined. We identified a study published in 2016 as our source of data. Five devices were evaluated. For these devices, QALYs were 7.3952, 7.2939, 7.4952, 7.1919, 7.2930; NMB: £142,005, £140,653, £144,184, £138,040, £140,261; tender scores: 64.53, 42.53, 100, 0, 36.15, respectively. We showed that incorporating the principles of cost-effectiveness into the tendering process is feasible for TKA devices. This can maximize the value for money for these devices.

Endovascular Thrombectomy for Ischemic Stroke Increases Disability-Free Survival, Quality of Life, and Life Expectancy and Reduces Cost

Background

Endovascular thrombectomy improves functional outcome in large vessel occlusion ischemic stroke. We examined disability, quality of life, survival and acute care costs in the EXTEND-IA trial, which used CT-perfusion imaging selection.

Methods

Large vessel ischemic stroke patients with favorable CT-perfusion were randomized to endovascular thrombectomy after alteplase versus alteplase-only. Clinical outcome was prospectively measured using 90-day modified Rankin scale (mRS). Individual patient expected survival and net difference in Disability/Quality-adjusted life years (DALY/QALY) up to 15 years from stroke were modeled using age, sex, 90-day mRS, and utility scores. Level of care within the first 90 days was prospectively measured and used to estimate procedure and inpatient care costs (US$ reference year 2014).

Results

There were 70 patients, 35 in each arm, mean age 69, median NIHSS 15 (IQR 12–19). The median (IQR) disability-weighted utility score at 90 days was 0.65 (0.00–0.91) in the alteplase-only versus 0.91 (0.65–1.00) in the endovascular group (p = 0.005). Modeled life expectancy was greater in the endovascular versus alteplase-only group (median 15.6 versus 11.2 years, p = 0.02). The endovascular thrombectomy group had fewer simulated DALYs lost over 15 years [median (IQR) 5.5 (3.2–8.7) versus 8.9 (4.7–13.8), p = 0.02] and more QALY gained [median (IQR) 9.3 (4.2–13.1) versus 4.9 (0.3–8.5), p = 0.03]. Endovascular patients spent less time in hospital [median (IQR) 5 (3–11) days versus 8 (5–14) days, p = 0.04] and rehabilitation [median (IQR) 0 (0–28) versus 27 (0–65) days, p = 0.03]. The estimated inpatient costs in the first 90 days were less in the thrombectomy group (average US$15,689 versus US$30,569, p = 0.008) offsetting the costs of interhospital transport and the thrombectomy procedure (average US$10,515). The average saving per patient treated with thrombectomy was US$4,365.

Conclusion

Thrombectomy patients with large vessel occlusion and salvageable tissue on CT-perfusion had reduced length of stay and overall costs to 90 days. There was evidence of clinically relevant improvement in long-term survival and quality of life.

Clinical Trial Registration

http://www.ClinicalTrials.gov NCT01492725 (registered 20/11/2011).

Estimating the number of UK stroke patients eligible for endovascular thrombectomy

INTRODUCTION

Endovascular thrombectomy is a highly effective treatment for acute ischemic stroke due to large arterial occlusion. Routine provision will require major changes in service configuration and workforce. An important first step is to quantify the population of stroke patients that could benefit. We estimated the annual UK population suitable for endovascular thrombectomy using standard or advanced imaging for patient selection.

PATIENTS AND METHODS

Evidence from randomised control trials and national registries was combined to estimate UK stroke incidence and define a decision-tree describing the endovascular thrombectomy eligible population.

RESULTS

Between 9620 and 10,920 UK stroke patients (approximately 10% of stroke admissions) would be eligible for endovascular thrombectomy annually. The majority (9140-9620) would present within 4 h of onset and be suitable for intravenous thrombolysis. Advanced imaging would exclude 500 patients presenting within 4 h, but identify an additional 1310 patients as eligible who present later.

DISCUSSION

Information from randomised control trials and large registry data provided the evidence criterion for 9 of the 12 decision points. The best available evidence was used for two decision points with sensitivity analyses to determine how key branches of the tree affected estimates. Using the mid-point estimate for eligibility (9.6% of admissions) and assuming national endovascular thrombectomy coverage, 4280 patients would have reduced disability.

CONCLUSION

A model combining published trials and register data suggests approximately 10% of all stroke admissions in the UK are eligible for endovascular thrombectomy. The use of advanced imaging based on current published evidence did not have a major impact on overall numbers but could alter eligibility status for 16% of cases.

Cost benefits of rapid recanalization using intraarterial thrombectomy

OBJECTIVES

Thrombolytic therapy is associated with favorable clinical outcomes after successful and rapid recanalization in patients with acute ischemic stroke. This study aimed to evaluate the cost benefits and clinical outcomes at 1 year after intraarterial thrombectomy (IAT) by the rapidity of the successful recanalization.

MATERIALS & METHODS

Clinical outcomes of and medical costs incurred by 230 patients with acute ischemic stroke who underwent IAT were compared by the rapidity from symptom onset to successful recanalization (2b/3 thrombolysis in cerebral infarction grade): ≤6-hr (n = 143), >6-hr (n = 31), and no-recanalization (n = 56). Clinical outcomes including functional independence (0-2 modified Rankin Score), mortality, and home-discharge checked at 1 year post-IAT were compared among the three groups. Cost utility was calculated using quality-adjusted life years (QALY) estimated using the EuroQol-5 dimensions-3 levels questionnaire and the fees paid for institutional rehabilitation during the year post-IAT, and, was compared among the groups.

RESULTS

Patients in the ≤6-hr group showed higher functional independence (≤6-hr, 70%; >6-hr, 40%; no-recanalization, 6%, p < .001) and home-discharge rate (73%, 52%, 21%, and respectively, p < .001), and lower mortality (10%, 16%, and 43%, respectively, p < .001) at 1 year after IAT than other two groups. The cost utility of the ≤6-hr group was $35,557/QALY higher than that of the >6-hr group, and $27.829/QALY higher than no-recanalization group.

CONCLUSIONS

Rapid and successful recanalization of the occluded intracranial vessels within 6 hr after the onset of symptoms resulted in markedly higher cost utility and functional independence at 1 year post-IAT.

Cost-effectiveness of mechanical thrombectomy using stent retriever after intravenous tissue plasminogen activator compared with intravenous tissue plasminogen activator alone in the treatment of acute ischaemic stroke due to large vessel occlusion in Spain

INTRODUCTION

To assess the cost-effectiveness of stent-retriever mechanical thrombectomy and intravenous tissue plasminogen activator compared with intravenous tissue plasminogen activator alone in patients with acute ischaemic stroke due to large vessel occlusions in Spain.

MATERIALS AND METHODS

Clinical data were taken from the SWIFT PRIME clinical trial. A lifetime Markov state transition model defined by the modified Rankin Scale score was developed to estimate costs and health outcomes (life years gained and quality adjusted life years). A Spanish National Health System perspective (direct medical costs) was considered. Resource utilisation and utilities were obtained from available published data and endorsed by an expert panel. Costs (€, 2016) were obtained from various Spanish sources. Deterministic and probabilistic sensitivity analyses were performed.

RESULTS

Stent-retriever thrombectomy after intravenous tissue plasminogen activator was associated with better outcomes (1.17 life years gained and 2.51 quality adjusted life years) and savings of €44,378, resulting in a dominant therapy over intravenous tissue plasminogen activator alone. A net monetary benefit of €119,744 was obtained considering a willingness-to-pay threshold of €30,000/quality adjusted life year gained. The combined therapy was also dominant in all sensitivity analyses, deterministic and probabilistic.

DISCUSSION

The results were consistent with a previously published cost-effectiveness analysis and reinforce the likeliness of the selection of stent-retriever mechanical thrombectomy plus intravenous tissue plasminogen activator over intravenous tissue plasminogen activator alone.

CONCLUSION

Stent-retriever thrombectomy after intravenous tissue plasminogen activator is a dominant alternative over intravenous tissue plasminogen activator alone (more effective and less costly) for the treatment of acute ischaemic stroke patients with large vessel occlusions in the Spanish setting.

Improved Detection of Anterior Circulation Occlusions: The "Delayed Vessel Sign" on Multiphase CT Angiography

BACKGROUND AND PURPOSE

Multiphase CTA, a technique to dynamically assess the vasculature in acute ischemic stroke, was primarily developed to evaluate collateral filling. We have observed that it is also useful in identifying distal anterior circulation occlusions due to delayed anterior circulation opacification on multiphase CTA, an observation we term the "delayed vessel sign." We aimed to determine the usefulness of this sign by comparing multiphase CTA with single-phase CTA.

MATERIALS AND METHODS

All 23 distal anterior circulation occlusions during a 2-year period were included. Ten M1-segment occlusions and 10 cases without a vessel occlusion were also included. All patients had follow-up imaging confirming the diagnosis. Initially, the noncontrast CT and first phase of the multiphase CTA study for each patient were blindly evaluated (2 neuroradiologists, 2 radiology trainees) for an anterior circulation occlusion. Readers' confidence, speed, and sensitivity of detection were recorded. Readers were then educated on the "delayed vessel sign," and each multiphase CTA study was re-examined for a vessel occlusion after at least 14 days.

RESULTS

There was significant improvement in the sensitivity of detection of distal anterior circulation vessel occlusions (P < .001), overall confidence (P < .001), and time taken to interpret (P < .001) with multiphase CTA compared with single-phase CTA. Readers preferred MIP images compared with source images in >90% of cases.

CONCLUSIONS

The delayed vessel sign is a reliable indicator of anterior circulation vessel occlusion, particularly in cases involving distal branches. Assessment of the later phases of multiphase CTA for the delayed vessel sign leads to a significant improvement in the speed and confidence of interpretation, compared with single-phase CTA.

Revolution in acute ischaemic stroke care: a practical guide to mechanical thrombectomy

Rapid, safe and effective arterial recanalisation to restore blood flow and improve functional outcome remains the primary goal of hyperacute ischaemic stroke management. The benefit of intravenous thrombolysis with recombinant tissue-type plasminogen activator for patients with severe stroke due to large artery occlusion is limited; early recanalisation is generally less than 30% for carotid, proximal middle cerebral artery or basilar artery occlusion. Since November 2014, nine positive randomised controlled trials of mechanical thrombectomy for large vessel occlusion in the anterior circulation have led to a revolution in the care of patients with acute ischaemic stroke. Its efficacy is unmatched by any previous therapy in stroke medicine, with a number needed to treat of less than 3 for improved functional outcome. With effectiveness shown beyond any reasonable doubt, the key challenge now is how to implement accessible, safe and effective mechanical thrombectomy services. This review aims to provide neurologists and other stroke physicians with a summary of the evidence base, a discussion of practical aspects of delivering the treatment and future challenges. We aim to give guidance on some of the areas not clearly described in the clinical trials (based on evidence where available, but if not, on our own experience and practice) and highlight areas of uncertainty requiring further research.

Time Course of Evolution of Disability and Cause-Specific Mortality After Ischemic Stroke: Implications for Trial Design

Background

Outcome in stroke trials is often based on a 3‐month modified Rankin scale (mRS). How 3‐month mRS relates to longer‐term outcomes will depend on late recovery, delayed stroke‐related deaths, recurrent strokes, and nonstroke deaths. We evaluated 3‐month mRS and death/disability at 1 and 5 years in a population‐based cohort study.

Methods and Results

In 3‐month survivors of ischemic stroke (Oxford Vascular Study; 2002‐2014), we related 3‐month mRS to disability (defined as mRS >2) at 1 and 5 years and/or death rates (age/sex adjusted). Accrual of disability and index‐stroke‐related and nonstroke deaths in each poststroke year was categorized according to 3‐month mRS. Among 1606 patients with acute ischemic stroke, 181 died within 3 months, but 126 index‐stroke‐related deaths and 320 other deaths occurred during the subsequent 4866 patient‐years of follow‐up up to 5 years. Although 69/126 (54.8%) post‐3‐month index‐stroke‐related deaths occurred after 1 year, mRS>2 at 1 year strongly predicted these deaths (adjusted hazard ratio=21.94, 95%CI 7.88‐61.09, P<0.0001). Consequently, a 3‐month mRS >2 was a strong independent predictor of death at both 1 year (adjusted hazard ratio=6.67, 95%CI 4.16‐10.69, P<0.0001) and 5 years (adjusted hazard ratio=2.93, 95%CI 2.38‐3.60, P<0.0001). Although mRS improved by ≥1 point from 3 months to 1 year in 317/1266 (25.0%) patients with 3‐month mRS ≥1, improvement in mRS after 1 year was limited (improvement by ≥1 point: 91/858 [10.6%]; improvement to mRS ≤2: 13/353 [3.7%]).

Conclusions

Our results reaffirm use of the 3‐month mRS outcome in stroke trials. Although later recovery does occur, extending follow‐up to 1 year would capture most long‐term stroke‐related disability. However, administrative mortality follow‐up beyond 1 year has the potential to demonstrate translation of early disability gains into additional reductions in long‐term mortality without much erosion by non‐stroke‐related deaths.

Observed Cost and Variations in Short Term Cost-Effectiveness of Therapy for Ischemic Stroke in Interventional Management of Stroke (IMS) III

BACKGROUND

Examination of linked data on patient outcomes and cost of care may help identify areas where stroke care can be improved. We report on the association between variations in stroke severity, patient outcomes, cost, and treatment patterns observed over the acute hospital stay and through the 12-month follow-up for subjects receiving endovascular therapy compared to intravenous tissue plasminogen activator alone in the IMS (Interventional Management of Stroke) III Trial.

METHODS AND RESULTS

Prospective data collected for a prespecified economic analysis of the trial were used. Data included hospital billing records for the initial stroke admission and subsequent detailed resource use after the acute hospitalization collected at 3, 6, 9, and 12 months. Cost of follow-up care varied 6-fold for patients in the lowest (0-1) and highest (20+) National Institutes of Health Stroke Scale category at 5 days, and by modified Rankin Scale at 3 months. The kind of resources used postdischarge also varied between treatment groups. Incremental short-term cost-effectiveness ratios varied greatly when treatments were compared for patient subgroups. Patient subgroups predefined by stroke severity had incremental cost-effectiveness ratios of $97 303/quality-adjusted life year (severe stroke) and $3 187 805/quality-adjusted life year (moderately severe stroke).

CONCLUSIONS

Detailed economic and resource utilization data from IMS III provide powerful evidence for the large effect that patient outcome has on the economic value of medical and endovascular reperfusion therapies. These data can be used to inform process improvements for stroke care and to estimate the cost-effectiveness of endovascular therapy in the US health system for stroke intervention trials.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Registration number: NCT00359424.

Long-term cost-effectiveness of thrombectomy for acute ischaemic stroke in real life: An analysis based on data from the Swedish Stroke Register (Riksstroke)

Background

Randomised controlled trials have demonstrated substantial clinical benefit for thrombectomy in patients with acute ischaemic stroke and proximal anterior circulation arterial occlusion.

Aim

We investigated the long-term cost-effectiveness of thrombectomy after thrombolysis versus thrombolysis alone using real-world outcome data on need for health care, home help and nursing home care.

Methods

We used real-life resource use and survival data from the Swedish Stroke Register and pooled outcomes from five randomised controlled trials published in 2015 in a newly constructed Markov cost-effectiveness model with a societal perspective. Data were stratified by age (18–64; 65–74; 75–84 years) and modified Rankin scale at three months for patients with an index ischaemic stroke in 2014 fulfilling inclusion criteria NIHSS ≥ 8 before treatment and treated with thrombolysis ( n = 710). Univariate sensitivity analyses explored robustness of results. A life-time perspective and 3% discount rate were applied.

Results

Thrombectomy increases the health care cost per patient (+GBP 9000) mainly because of intervention costs, but the reduced burden on the social services (home help services −GBP 13,000; nursing home care −GBP 26,000) implies overall cost savings. The average patient gain was 1.0 quality-adjusted life year (QALY) with higher gains for younger age groups. Thrombectomy was a dominant strategy in the base case and all sensitivity analyses where social services were considered.

Conclusion

Thrombectomy has a small effect on hospital costs except for the direct intervention cost. However, thrombectomy is highly likely to lead to substantial cost savings in the social service sector, up to four times the increase in health-care costs.

Safety and efficacy of thrombectomy in acute ischaemic stroke (REVASCAT): 1-year follow-up of a randomised open-label trial

BACKGROUND

The REVASCAT trial and other studies have shown that the neurovascular thrombectomy improves outcomes at 90 days post stroke. However, whether the observed benefit is sustained in the long term remains unknown. We report the results of the prespecified 12-month analysis of the REVASCAT trial.

METHODS

Patients with acute ischaemic stroke who could be treated within 8 h of symptom onset were randomly assigned to medical therapy (including intravenous alteplase when eligible) and neurovascular thrombectomy with Solitaire FR or medical therapy alone. The main secondary outcome measure at 1 year follow-up was disability, measured using the modified Rankin Scale (mRS), ranging from 0 (no symptoms) to 6 (death) with categories 5 (severe disability) and 6 (death) collapsed into one category (severe disability or death), analysed as the distribution of the mRS. Additional prespecified secondary outcome measures included health-related quality of life measured with the EuroQol five dimensions questionnaire (EQ-5D) utility index (ranging from -0·3 to 1, higher values indicate better quality of life), the rate of functional independence (mRS 0-2), and cognitive function measured with the Trail Making Test (reported elsewhere). Treatment allocation was open label but endpoints at 12 months were assessed by masked investigators. The trial was registered at ClinicalTrials.gov, number NCT01692379.

FINDINGS

From Nov 24, 2012, to Dec 12, 2014, 206 patients were randomly assigned to medical therapy plus endovascular treatment (n=103) or medical treatment alone (n=103), at four centres in Catalonia, Spain. At 12 months post randomisation, based on 205 of 206 outcomes available at 12 months, thrombectomy reduced disability over the range of the mRS (common adjusted odds ratio [aOR] 1·80, 95% CI 1·09-2·99), and improved functional independence (mRS=0-2; 45 [44%] of 103 patients vs 31 [30%] of 103 patients; aOR 1·86, 95% CI 1·01-3·44). Health-related quality of life was superior in the thrombectomy group (mean EQ-5D utility index score, 0·46 [SD 0·38] in the thrombectomy group vs 0·33 [0·33] in the control group, difference 0·12 [95% CI 0·03-0·22]; p=0·01). 1-year mortality was 23% (24 of 103 patients) in the thrombectomy group versus 24% (25 of 103 patients) in the control group.

INTERPRETATION

At 12 months follow-up, neurovascular thrombectomy reduced post-stroke disability and improved health-related quality of life, indicating sustained benefit. These findings have important clinical and public health implications for evaluating the cost-effectiveness of the intervention in the long term.

FUNDING

Fundació Ictus Malaltia Vascular through an unrestricted grant from Medtronic.

Intravenous thrombolysis before endovascular therapy for large vessel strokes can lead to significantly higher hospital costs without improving outcomes

Background

Limited efficacy of IV recombinant tissue plasminogen activator (rt-PA) for large vessel occlusions (LVO) raises doubts about its utility prior to endovascular therapy.

Purpose

To compare outcomes and hospital costs for anterior circulation LVOs (middle cerebral artery, internal carotid artery terminus (ICA-T)) treated with either primary endovascular therapy alone (EV-Only) or bridging therapy (IV+EV)).

Methods

A single-center retrospective analysis was performed. Clinical and demographic data were collected prospectively and relevant cost data were obtained for each patient in the study.

Results

90 consecutive patients were divided into EV-Only (n=52) and IV+EV (n=38) groups. There was no difference in demographics, stroke severity, or clot distribution. The mean (SD) time to presentation was 5:19 (4:30) hours in the EV-Only group and 1:46 (0:52) hours in the IV+EV group (p<0.0001). Recanalization: EV-Only 35 (67%) versus IV+EV 31 (81.6%) (p=0.12). Favorable outcome: EV-Only 26 (50%) versus IV+EV 22 (58%) (p=0.45). For patients presenting within 4.5 hours (n=64): Recanalization: EV-Only 21/26 (81%) versus IV+EV 31/38 (81.6%) (p=0.93). Favorable outcome: EV-Only 14/26 (54%) versus IV+EV 22/38 (58%) (p=0.75). There was no significant difference in rates of hemorrhage, mortality, home discharge, or length of stay. A stent retriever was used in 67 cases (74.4%), with similar recanalization, outcomes, and number of passes in the EV-Only and IV+EV groups. The mean (SD) total hospital cost was $33 810 (13 505) for the EV-Only group and $40 743 (17 177) for the IV+EV group (p=0.02). The direct cost was $23 034 (8786) for the EV-Only group and $28 711 (11 406) for the IV+EV group (p=0.007). These significantly higher costs persisted for the subgroup presenting in <4.5 hours and the stent retriever subgroup. IV rt-PA administration independently predicted higher hospital costs.

Conclusions

IV rt-PA did not improve recanalization, thrombectomy efficacy, functional outcomes, or length of stay. Combined therapy was associated with significantly higher total and direct hospital costs than endovascular therapy alone.