A Randomized Trial of Intravenous Alteplase before Endovascular Treatment for Stroke

N Engl J Med. 2021 Nov 11;385(20):1833-1844. doi: 10.1056/NEJMoa2107727.


Background: The value of administering intravenous alteplase before endovascular treatment (EVT) for acute ischemic stroke has not been studied extensively, particularly in non-Asian populations.

Methods: We performed an open-label, multicenter, randomized trial in Europe involving patients with stroke who presented directly to a hospital that was capable of providing EVT and who were eligible for intravenous alteplase and EVT. Patients were randomly assigned in a 1:1 ratio to receive EVT alone or intravenous alteplase followed by EVT (the standard of care). The primary end point was functional outcome on the modified Rankin scale (range, 0 [no disability] to 6 [death]) at 90 days. We assessed the superiority of EVT alone over alteplase plus EVT, as well as noninferiority by a margin of 0.8 for the lower boundary of the 95% confidence interval for the odds ratio of the two trial groups. Death from any cause and symptomatic intracerebral hemorrhage were the main safety end points.

Results: The analysis included 539 patients. The median score on the modified Rankin scale at 90 days was 3 (interquartile range, 2 to 5) with EVT alone and 2 (interquartile range, 2 to 5) with alteplase plus EVT. The adjusted common odds ratio was 0.84 (95% confidence interval [CI], 0.62 to 1.15; P = 0.28), which showed neither superiority nor noninferiority of EVT alone. Mortality was 20.5% with EVT alone and 15.8% with alteplase plus EVT (adjusted odds ratio, 1.39; 95% CI, 0.84 to 2.30). Symptomatic intracerebral hemorrhage occurred in 5.9% and 5.3% of the patients in the respective groups (adjusted odds ratio, 1.30; 95% CI, 0.60 to 2.81).

Conclusions: In a randomized trial involving European patients, EVT alone was neither superior nor noninferior to intravenous alteplase followed by EVT with regard to disability outcome at 90 days after stroke. The incidence of symptomatic intracerebral hemorrhage was similar in the two groups. (Funded by the Collaboration for New Treatments of Acute Stroke consortium and others; MR CLEAN-NO IV ISRCTN number, ISRCTN80619088.).

Publication types

  • Equivalence Trial
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Combined Modality Therapy
  • Endovascular Procedures
  • Europe
  • Female
  • Fibrinolytic Agents / therapeutic use
  • Humans
  • Infusions, Intravenous
  • Ischemic Stroke / drug therapy*
  • Male
  • Middle Aged
  • Severity of Illness Index
  • Thrombectomy*
  • Tissue Plasminogen Activator / therapeutic use
  • Treatment Outcome


  • Fibrinolytic Agents
  • Tissue Plasminogen Activator

Associated data

  • ISRCTN/ISRCTN80619088