Cost-Effectiveness of Solitaire Stent Retriever Thrombectomy for Acute Ischemic Stroke: Results From the SWIFT-PRIME Trial (Solitaire With the Intention for Thrombectomy as Primary Endovascular Treatment for Acute Ischemic Stroke)

Abstract

Background and purpose: Clinical trials have demonstrated improved 90-day outcomes for patients with acute ischemic stroke treated with stent retriever thrombectomy plus tissue-type plasminogen activator (SST+tPA) compared with tPA. Previous studies suggested that this strategy may be cost-effective, but models were derived from pooled data and older assumptions.

Methods: In this prospective economic substudy conducted alongside the SWIFT-PRIME trial (Solitaire With the Intention for Thrombectomy as Primary Endovascular Treatment for Acute Ischemic Stroke), in-trial costs were measured for patients using detailed medical resource utilization and hospital billing data. Utility weights were assessed at 30 and 90 days using the EuroQol-5 dimension questionnaire. Post-trial costs and life-expectancy were estimated for each surviving patient using a model based on trial data and inputs derived from a contemporary cohort of ischemic stroke survivors.

Results: Index hospitalization costs were $17 183 per patient higher for SST+tPA than for tPA ($45 761 versus $28 578; P<0.001), driven by initial procedure costs. Between discharge and 90 days, costs were $4904 per patient lower for SST+tPA than for tPA ($11 270 versus $16 174; P=0.014); total 90-day costs remained higher with SST+tPA ($57 031 versus $44 752; P<0.001). Higher utility values for SST+tPA led to higher in-trial quality-adjusted life years (0.131 versus 0.105; P=0.005). In lifetime projections, SST+tPA was associated with substantial gains in quality-adjusted life years (6.79 versus 5.05), cost savings of $23 203 per patient and was economically dominant when compared with tPA in 90% of bootstrap replicates.

Conclusions: Among patients with acute ischemic stroke enrolled in the SWIFT-PRIME trial, SST increased initial treatment costs, but was projected to improve quality-adjusted life-expectancy and reduce healthcare costs over a lifetime horizon compared with tPA.

Clinical trial registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01657461.

Keywords: quality-adjusted life years; stents; stroke; thrombectomy; tissue-type plasminogen activator.

Conflict of interest statement

Disclosures

The University of California, Regents receives funding for Dr Saver’s services as a scientific consultant regarding trial design and conduct to Covidien and Stryker and is an employee of the University of California, which holds a patent on retriever devices for stroke. Dr Goyal serves as a consultant to Medtronic/Covidien, Stryker, Microvention and has a patent Systems of stroke diagnosis licensed to GE Healthcare. Drs Bonafe, Diener, Pereira, Hacke, Jansen, Mattle, and Lopes served as scientific consultants regarding trial design and conduct to Medtronic/Covidien. Dr Levy serves as a scientific consultant to Medtronic/Covidien, has shareholder/ownership interest with Intratech Medical Ltd, Blockade Medical LLC, has received fees from Abbott for carotid training, and has served as an expert witness for Renders Medical/Legal opinion. Dr Albers has an equity interest and is a consultant for iSchemaView, which provided the RAPID software and Core Laboratory services for the SWIFT-PRIME trial (Solitaire With the Intention for Thrombectomy as Primary Endovascular Treatment for Acute Ischemic Stroke) and has been a consultant for Medtronic. Dr Cognard serves as a scientific consultant to Medtronic/Covidien, Sequentiel, and Codman. Dr Jovin serves as a scientific consultant regarding trial design and conduct to Medtronic/Covidien and is on the advisory board for Silk Road Medical and Blockade Medical LLC. Dr Nogueira serves as a scientific consultant to Medtronic/Covidien, Stryker Neurovascular, and Penumbra. Dr Siddiqui has financial interests in StimSox, Valor Medical, Neuro Technology Investors, Cardinal Health, Medina Medical Systems, Buffalo Technology Partners, Inc, and International Medical Distribution Partners, serves as a consultant to Codman & Shurtleff, Inc, GuidePoint Global Consulting, Penumbra, Stryker, MicroVention, W.L. Gore & Associates, Three Rivers Medical, Corindus, Inc, Amnis Therapeutics, Ltd, CereVasc, LLC, Pulsar Vascular, The Stroke Project, Inc, Cerebrotech Medical Systems, Inc, Rapid Medical, Neuravi, Silk Road Medical, Rebound Medical, Intersocietal Accreditation Committee, Penumbra, 3D Separator trial, Covidien (Now Medtronic), and is part of the steering committee for SWIFT-PRIME and SWIFT DIRECT (Solitaire With the Intention for Thrombectomy Plus Intravenous t-PA Versus Direct Solitaire Stent-Retriever Thrombectomy in Acute Anterior Circulation Stroke) trials, MicroVention, FRED trial (Flow Redirection Intraluminal Device), CONFIDENCE study (Pivotal Study of the MicroVention, Inc, Carotid Artery Stent System Used in Conjunction With the Nanoparasol Embolic Protection System for the Treatment of Carotid Artery Stenosis in Patients at Elevated Risk for Adverse Events From Carotid Endarterectomy), LARGE trial (Long-Acting Beta Agonist Response by Genotype), POSITIVE trial (Perfusion Imaging Selection of Ischemic Stroke Patients for Endovascular Therapy), Penumbra COMPASS and INVEST (Minimally Invasive Endoscopic Surgery vs Medical Management in Supratentorial Intraparenchymal Hemorrhage) trials. Dr Yavagal serves as a scientific consultant to Medtronic/Covidien and Neuralanalytics, Inc. The University of California, Regents receives funding for Dr Jahan’s services as a scientific consultant regarding trial design and conduct to Medtronic/Covidien, and is an employee of the University of California, which holds a patent on retriever devices for stroke. The other authors report no conflicts.

© 2016 American Heart Association, Inc.

Figures

Figure 1

Utility comparison during 90-day trial period. EQ-5D indicates EuroQol-5 dimension; and IV tPA, intravenous tissue-type plasminogen activator.

Figure 2

Scatter plot showing the joint distribution of the difference in lifetime cost and quality-adjusted life-expectancy between intravenous tissue-type plasminogen activator (IV tPA) alone and stent retriever thrombectomy according to bootstrap simulation (1000 replicates). The large solid dot indicates the base case value of Δ costs = $23 203 and Δ quality-adjusted life years (QALYs) = 1.743. The solid, diagonal line indicates the incremental cost-effectiveness ratio threshold of $50 000 per QALY gained.

Figure 3

Time to breakeven point where long-term costs associated with stent retriever thrombectomy are exceeded by higher long term costs in the intravenous tissue-type plasminogen activator (IV tPA)–alone group.