TENSION was an investigator-initiated, randomized controlled, open label, blinded endpoint, European, two-arm, postmarket study to compare the safety and effectiveness of thrombectomy as compared to best medical care alone in stroke patients with extended stroke lesions. Patients were eligible, if they presented with an Alberta Stroke Program Early Computed Tomography Scan score of 3–5. The vision of TENSION ia to reduce the burden of death and disability from stroke by providing innovative effective treatment to severe stroke patients for whom currently no effective treatment is available.

MAIN FINDINGS: From July 17, 2018, to Feb 21, 2023, 253 patients were randomly assigned, with 125 patients assigned to endovascular thrombectomy and 128 to medical treatment alone. The trial was stopped early for efficacy after the first pre-planned interim analysis. At 90 days, endovascular thrombectomy was associated with a shift in the distribution of scores on the modified Rankin Scale towards better outcome (adjusted common OR 2·58 [95% CI 1·60–4·15]; p=0·0001) and with lower mortality (hazard ratio 0·67 [95% CI 0·46–0·98]; p=0·038). Symptomatic intracranial haemorrhage occurred in seven (6%) patients with thrombectomy and in six (5%) with medical treatment alone.

Endovascular thrombectomy was associated with improved functional outcome and lower mortality in patients with acute ischaemic stroke from large vessel occlusion with established large infarct in a setting using non- contrast CT as the predominant imaging modality for patient selection.

TENSION receives funding by the European Union’s Horizon 2020 research and innovation programme.

ClinicalTrials.gov Identifier, NCT03094715

Online Publication: https://doi.org/10.1016/ S0140-6736(23)02032-9