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Primary findings of the TENSION trial

Today, on 11 October 2023, the primary findings of the TENSION (The Efficacy and Safety of Thrombectomy in Stroke with extended lesion and extended time window) trial were released in The Lancet, coinciding with a presentation at the World Stroke Congress in Toronto, Canada.

The trial was stopped early for efficacy after the first pre-planned interim analysis. Overall, 253 patients were randomized. At 90 days, there was a shift in the distribution of scores on the modified Rankin Score toward better outcomes in favor of endovascular thrombectomy.

As yet, there are three randomized trials of endovascular thombectomy for treatment of acute ischemic stroke with large core (RESCUE-Japan LIMIT, ANGEL-ASPECT, SELECT2). These trials have reported comparable results, but they are limited especially with regards to generalizability of their results and have not yet resulted in a change of guidelines and clinical practice.

The TENSION study was conducted in 40 centres in 8 countries in Europe and Canada and patient enrolment was based on standard of care stroke imaging with non-contrast CT in 82% and MRI in 18% reflecting clinical practice worldwide. By design, perfusion imaging or post-processing using commercial software was not required, as in previous trials.

The results of the study will provide both new and highly relevant clinical information for the field of thrombectomy in large core acute ischaemic stroke. 

Furthermore, endovascular thrombectomy in the study was not only associated with better outcomes as in the previous three studies, but also with lower mortality at 90 days, which was not reported in any of the other studies.

> Read the primary findings of TENSION on The Lancet


ESMINT is one of the project partners and is responsible for the Work Package “Dissemination, transfer, scientific data pooling and sharing”.

TENSION strives to compare the safety and effectiveness of endovascular thrombectomy as compared to best medical care alone in the treatment of acute ischemic stroke patients with extended stroke lesions defined by an Alberta Stroke Program Early CT Score (ASPECTS) score of 3-5 and in an extended time window (up to 12 hours or unknown time of symptom onset).

The primary endpoint will be functional outcome assessed by the modified Rankin scale at 90 days post-stroke (“mRS shift analysis”). By this, the study aims to provide innovative treatment to patients with severe stroke to reduce the individual and societal burden of death and dependency from a stroke.

> Read the ESMINT press release about TENSION (20 July 2018)

> More information (TENSION website)

Project Partners

The TENSION study consortium consists of 15 participating organisations based in eleven different countries. It brings together renowned researchers and clinicians from across Europe, each with a strong scientific and clinical background and outstanding expertise in the field of acute stroke diagnostics and treatment.

The TENSION Consortium consists of the following partners:

  • Universitätsklinikum Hamburg-Eppendorf
  • Universitätsklinikum Heidelberg
  • Medizinische Universität Innsbruck
  • Charles University, Hradec Kralove
  • Aarhus Universitetshospital
  • CHU de Reims
  • Oslo University Hospital
  • Stockholms Lans Landsting
  • Comenius University’s Jessenius, Faculty of Medicine and University Hospital
  • Hospices Civils de Lyon
  • ECRIN – European Clinical Research Infrastructure Network
  • eppdata GmbH
  • ESMINT – European Society for Minimally Invasive Neurological Therapy
  • SAFE – Stroke Alliance for Europe
  • ICHOM – International Consortium for Health Outcomes Measurement

TENSION in the media


Bendszus M, Fiehler J, Thomalla: New Interventional Stroke Trials. Editorial Clinical Neuroradiology, March 2019, Volume 29, Issue 1, pp 1–1.

Bendszus M, Bonekamp S, Berge E, Boutitie F, Brouwer P, Gizewski E, Krajina A, Pierot L, Randall G, Simonsen CZ, Zeleňák K, Fiehler J, Thomalla G: A randomized controlled trial to test efficacy and safety of thrombectomy in stroke with extended lesion and extended time window.  Int J Stroke. 2018 Aug 29.

Press releases

20.07.2018: ESMINT (European Society of Minimally Invasive Neurological Therapy): “ESMINT partners in EU funded research project: Clinical study starts in eight European countries”.

20.07.2018: NeuroNews, “Clinical study looking into mechanical thrombectomy for major stroke starts in eight European countries”.

02.07.2018: Hamburg, Germany: “Ist die Katheterbehandlung auch bei größeren Schlaganfällen effektiv?”.

02.07.2018: Heidelberg, Germany: “Aktuelle Studie: Ist die Katheterbehandlung auch bei größeren Schlaganfällen effektiv?”.