Stent-Thrombectomy May Be New Standard of Care for Ischemic Stroke Interview with:
Dr Bruce Campbell MBBS(Hons), BMedSc, PhD, FRACP
Consultant Neurologist, Head of Hyperacute Stroke
Department of Neurology     Royal Melbourne Hospital
NHMRC Early Career Research Fellow
Melbourne Brain Centre @ RMH Department of Medicine
University of Melbourne Australia

MedicalResearch: What is the background for this study? What are the main findings?

Dr. Campbell: EXTEND-IA was a randomised trial comparing standard thrombolysis with tPA plus endovascular stent-thrombectomy versus tPA alone in ischemic stroke patients selected for the presence of major vessel occlusion and salvageable brain tissue using CT perfusion imaging. It was designed in 2011 at a time when there was uncertainty about the effectiveness of endovascular therapy which deepened in 2013 with the publication of 3 neutral trials. The recent publication of the Dutch MR-CLEAN study showing improved outcomes with stent-thrombectomy was a major advance and prompted a data safety and monitoring committee review of the EXTEND-IA data leading to early termination of the trial for efficacy.

The key findings from EXTEND-IA were that the addition of stent-thrombectomy to tPA led to a dramatic increase in restoration of blood flow to the brain from 34% to 89%. This translated to markedly improved outcomes at 3 months with 71% of stent-thrombectomy patients compared with 40% of tPA-only patients regaining independence. The 3 trials released today were remarkably consistent in their outcomes and this provides a solid evidence base to recommend stent-thrombectomy as the new standard of care for patients with large vessel ischemic stroke.

Patients who were treated with stent-thrombectomy in EXTEND-IA had more than double the rate of reperfusion (restoration of blood flow to the brain) compared to the standard tPA patients and this translated to a 31% absolute increase in the proportion of patients living independently at 3 months.

MedicalResearch: What should clinicians and patients take away from your report

Dr. Campbell: Putting the results of recent trials together, there is clear evidence that stent-thrombectomy improves outcomes for patients with large vessel ischemic stroke.

In many countries, including Australia, there are a limited number of centers that can provide stent-thrombectomy and limited neurointerventionists trained to perform the procedure. Currently many patients have to be transferred between hospitals and rural patients rarely have access within a suitable timeframe.

Given the strong evidence for improved outcome, systems of care need to be re-designed and adequately resourced to implement the findings of this research. Whilst stent-thrombectomy may only be suitable for ~10% of all stroke patients, these are the group most likely to suffer long term disability and death and so the potential societal benefit is highly significant. Initial analysis of treatment costs suggests that stent-thrombectomy is highly cost effective.

MedicalResearch: What recommendations do you have for future research as a result of this study?

Dr. Campbell: The key differences between recent studies revolve around the method of patient selection using brain imaging. These methods have led to positive trials but we cannot exclude some benefit of stent-thrombectomy in patients excluded from the trials and this requires further research. EXTEND-IA used CT perfusion which we find very useful in guiding our decision-making. The fully automated RAPID software (Stanford University) provided fast, standardised and easy to interpret images that determined eligibility for the study and proved robust across centers with a wide range of imaging experience.


Endovascular Therapy for Ischemic Stroke with Perfusion-Imaging Selection

Bruce C.V. Campbell, M.D., Peter J. Mitchell, M.D., Timothy J. Kleinig, M.D., Helen M. Dewey, M.D., Leonid Churilov, Ph.D., Nawaf Yassi, M.D., Bernard Yan, M.D., Richard J. Dowling, M.D., Mark W. Parsons, M.D., Thomas J. Oxley, M.D., Teddy Y. Wu, M.D., Mark Brooks, M.D., Marion A. Simpson, M.D., Ferdinand Miteff, M.D., Christopher R. Levi, M.D., Martin Krause, M.D., Timothy J. Harrington, M.D., Kenneth C. Faulder, M.D., Brendan S. Steinfort, M.D., Miriam Priglinger, M.D., Timothy Ang, M.D., Rebecca Scroop, M.D., P. Alan Barber, M.D., Ben McGuinness, M.D., Tissa Wijeratne, M.D., Thanh G. Phan, M.D., Winston Chong, M.D., Ronil V. Chandra, M.D., Christopher F. Bladin, M.D., Monica Badve, M.D., Henry Rice, M.D., Laetitia de Villiers, M.D., Henry Ma, M.D., Patricia M. Desmond, M.D., Geoffrey A. Donnan, M.D., and Stephen M. Davis, M.D. for the EXTEND-IA Investigators

February 11, 2015DOI: 10.1056/NEJMoa1414792

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