Peter J Mitchell1, Bernard Yan2, Leonid Churilov3, Richard J Dowling4, Steven J Bush4, Andrew Bivard2, Xiao Chuan Huo5, Guoqing Wang6, Shi Yong Zhang7, Mai Duy Ton8, Dennis J Cordato9, Timothy J Kleinig10, Henry Ma11, Ronil V Chandra12, Helen Brown13, Bruce C V Campbell14, Andrew K Cheung15, Brendan Steinfort16, Rebecca Scroop17, Kendal Redmond13, Ferdinand Miteff18, Yan Liu19, Dang Phuc Duc20, Hal Rice21, Mark W Parsons22, Teddy Y Wu23, Huy-Thang Nguyen24, Geoffrey A Donnan2, Zhong Rong Miao5, Stephen M Davis2. 1. Department of Radiology, The Royal Melbourne Hospital, University of Melbourne, Parkville, VIC, Australia. Electronic address: peter.mitchell@mh.org.au. 2. Department of Medicine and Neurology, Melbourne Brain Centre, The Royal Melbourne Hospital, University of Melbourne, Parkville, VIC, Australia. 3. Melbourne Medical School, The Royal Melbourne Hospital, University of Melbourne, Parkville, VIC, Australia. 4. Department of Radiology, The Royal Melbourne Hospital, University of Melbourne, Parkville, VIC, Australia. 5. Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Capital Medical University, Fengtai District, Beijing, China. 6. Department of Neurology, Bin Zhou People's Hospital, Shandong Province, China. 7. Department of Interventional Neuroradiology, Beijing Fengtai You'anmen Hospital, Beijing, China. 8. Stroke Centre, Bach Mai Hospital, Ha Noi Medical University, Ha Noi, Vietnam. 9. Department of Neurology, Liverpool Hospital, University of New South Wales, Liverpool, Sydney, NSW, Australia; South Western Sydney Clinical School, University of New South Wales Medicine, Sydney, NSW, Australia; Ingham Institute for Applied Medical Research, Liverpool, Sydney, NSW, Australia. 10. Department of Neurology, Royal Adelaide Hospital, Adelaide, SA, Australia. 11. Department of Medicine, School of Clinical Sciences, Monash University, Monash Health Centre, Clayton, VIC, Australia. 12. NeuroInterventional Radiology, Department of Imaging, School of Clinical Sciences, Monash University, Monash Health Centre, Clayton, VIC, Australia. 13. Princess Alexandra Hospital, Woolloongabba, QLD, Australia. 14. Department of Medicine and Neurology, Melbourne Brain Centre, The Royal Melbourne Hospital, University of Melbourne, Parkville, VIC, Australia; Florey Institute of Neuroscience and Mental Health, The Royal Melbourne Hospital, University of Melbourne, Parkville, VIC, Australia. 15. Department of Neurointerventional Radiology, Liverpool Hospital, University of New South Wales, Liverpool, Sydney, NSW, Australia; South West Sydney Clinical Campuses, University of New South Wales Medicine, Sydney, NSW, Australia; Ingham Institute for Applied Medical Research, Liverpool, Sydney, NSW, Australia. 16. Department of Neurosurgery, Neurointervention Unit, Interventional Neuroradiology Department, Royal North Shore Hospital, St Leonards, NSW, Australia. 17. Department of Radiology, Royal Adelaide Hospital, Adelaide, SA, Australia. 18. John Hunter Hospital, New Lambton Heights, NSW, Australia. 19. Department of Neurology, JingJiang People's Hospital, The Seventh Affiliated Hospital of Yangzhou University, Jiangsu, China. 20. Department of Stroke, Military Hospital 103, Ha Noi, Vietnam. 21. Department of Neurointervention, Gold Coast University Hospital, Southport, QLD, Australia. 22. Department of Neurology, Liverpool Hospital, University of New South Wales, Liverpool, Sydney, NSW, Australia; Ingham Institute for Applied Medical Research, Liverpool, Sydney, NSW, Australia. 23. Department of Neurology, Christchurch Hospital, Christchurch, New Zealand. 24. Pham Ngoc Thach University of Medicine, The People's Hospital 115, Ho Chi Minh, Vietnam.
Abstract
BACKGROUND: The benefit of combined treatment with intravenous thrombolysis before endovascular thrombectomy in patients with acute ischaemic stroke caused by large vessel occlusion remains unclear. We hypothesised that the clinical outcomes of patients with stroke with large vessel occlusion treated with direct endovascular thrombectomy within 4·5 h would be non-inferior compared with the outcomes of those treated with standard bridging therapy (intravenous thrombolysis before endovascular thrombectomy). METHODS: DIRECT-SAFE was an international, multicentre, prospective, randomised, open-label, blinded-endpoint trial. Adult patients with stroke and large vessel occlusion in the intracranial internal carotid artery, middle cerebral artery (M1 or M2), or basilar artery, confirmed by non-contrast CT and vascular imaging, and who presented within 4·5 h of stroke onset were recruited from 25 acute-care hospitals in Australia, New Zealand, China, and Vietnam. Eligible patients were randomly assigned (1:1) via a web-based, computer-generated randomisation procedure stratified by site of baseline arterial occlusion and by geographic region to direct endovascular thrombectomy or bridging therapy. Patients assigned to bridging therapy received intravenous thrombolytic (alteplase or tenecteplase) as per standard care at each site; endovascular thrombectomy was also per standard of care, using the Trevo device (Stryker Neurovascular, Fremont, CA, USA) as first-line intervention. Personnel assessing outcomes were masked to group allocation; patients and treating physicians were not. The primary efficacy endpoint was functional independence defined as modified Rankin Scale score 0-2 or return to baseline at 90 days, with a non-inferiority margin of -0·1, analysed by intention to treat (including all randomly assigned and consenting patients) and per protocol. The intention-to-treat population was included in the safety analyses. The trial is registered with ClinicalTrials.gov, NCT03494920, and is closed to new participants. FINDINGS: Between June 2, 2018, and July 8, 2021, 295 patients were randomly assigned to direct endovascular thrombectomy (n=148) or bridging therapy (n=147). Functional independence occurred in 80 (55%) of 146 patients in the direct thrombectomy group and 89 (61%) of 147 patients in the bridging therapy group (intention-to-treat risk difference -0·051, two-sided 95% CI -0·160 to 0·059; per-protocol risk difference -0·062, two-sided 95% CI -0·173 to 0·049). Safety outcomes were similar between groups, with symptomatic intracerebral haemorrhage occurring in two (1%) of 146 patients in the direct group and one (1%) of 147 patients in the bridging group (adjusted odds ratio 1·70, 95% CI 0·22-13·04) and death in 22 (15%) of 146 patients in the direct group and 24 (16%) of 147 patients in the bridging group (adjusted odds ratio 0·92, 95% CI 0·46-1·84). INTERPRETATION: We did not show non-inferiority of direct endovascular thrombectomy compared with bridging therapy. The additional information from our study should inform guidelines to recommend bridging therapy as standard treatment. FUNDING: Australian National Health and Medical Research Council and Stryker USA.
BACKGROUND: The benefit of combined treatment with intravenous thrombolysis before endovascular thrombectomy in patients with acute ischaemic stroke caused by large vessel occlusion remains unclear. We hypothesised that the clinical outcomes of patients with stroke with large vessel occlusion treated with direct endovascular thrombectomy within 4·5 h would be non-inferior compared with the outcomes of those treated with standard bridging therapy (intravenous thrombolysis before endovascular thrombectomy). METHODS: DIRECT-SAFE was an international, multicentre, prospective, randomised, open-label, blinded-endpoint trial. Adult patients with stroke and large vessel occlusion in the intracranial internal carotid artery, middle cerebral artery (M1 or M2), or basilar artery, confirmed by non-contrast CT and vascular imaging, and who presented within 4·5 h of stroke onset were recruited from 25 acute-care hospitals in Australia, New Zealand, China, and Vietnam. Eligible patients were randomly assigned (1:1) via a web-based, computer-generated randomisation procedure stratified by site of baseline arterial occlusion and by geographic region to direct endovascular thrombectomy or bridging therapy. Patients assigned to bridging therapy received intravenous thrombolytic (alteplase or tenecteplase) as per standard care at each site; endovascular thrombectomy was also per standard of care, using the Trevo device (Stryker Neurovascular, Fremont, CA, USA) as first-line intervention. Personnel assessing outcomes were masked to group allocation; patients and treating physicians were not. The primary efficacy endpoint was functional independence defined as modified Rankin Scale score 0-2 or return to baseline at 90 days, with a non-inferiority margin of -0·1, analysed by intention to treat (including all randomly assigned and consenting patients) and per protocol. The intention-to-treat population was included in the safety analyses. The trial is registered with ClinicalTrials.gov, NCT03494920, and is closed to new participants. FINDINGS: Between June 2, 2018, and July 8, 2021, 295 patients were randomly assigned to direct endovascular thrombectomy (n=148) or bridging therapy (n=147). Functional independence occurred in 80 (55%) of 146 patients in the direct thrombectomy group and 89 (61%) of 147 patients in the bridging therapy group (intention-to-treat risk difference -0·051, two-sided 95% CI -0·160 to 0·059; per-protocol risk difference -0·062, two-sided 95% CI -0·173 to 0·049). Safety outcomes were similar between groups, with symptomatic intracerebral haemorrhage occurring in two (1%) of 146 patients in the direct group and one (1%) of 147 patients in the bridging group (adjusted odds ratio 1·70, 95% CI 0·22-13·04) and death in 22 (15%) of 146 patients in the direct group and 24 (16%) of 147 patients in the bridging group (adjusted odds ratio 0·92, 95% CI 0·46-1·84). INTERPRETATION: We did not show non-inferiority of direct endovascular thrombectomy compared with bridging therapy. The additional information from our study should inform guidelines to recommend bridging therapy as standard treatment. FUNDING: Australian National Health and Medical Research Council and Stryker USA.