Large-Vessel Occlusion Stroke: Effect of Recanalization on Outcome Depends on the National Institutes of Health Stroke Scale Score

J Stroke Cerebrovasc Dis. 2015 Jul;24(7):1532-9. doi: 10.1016/j.jstrokecerebrovasdis.2015.03.020. Epub 2015 Apr 23.


Background: Arterial recanalization is currently considered the main standard of successful early management of acute ischemic stroke. Intravenous (IV) thrombolysis with tissue plasminogen activator (tPa) is the only Food and Drug Administration-approved medical treatment. Large-vessel occlusion, estimated to account for up to 40% of all acute ischemic strokes, is often refractory to IV thrombolysis and is associated with a poor patient outcome. Mechanical recanalization procedures are therefore increasingly used in the treatment of large-vessel occlusion refractory to, or presenting outside the accepted time window for, IV thrombolysis. The aim of this study was to investigate the effect of early vessel recanalization on clinical outcome in patients with large-vessel occlusion stroke.

Methods: This is a single-center cohort study, analyzing prospectively collected data on 152 patients with large-vessel occlusion and acute ischemic stroke. Seventy-one patients received endovascular treatment (of whom 57.7% also received IV tPA), and 81 (55.6% of whom also received IV tPa) were not treated with endovascular therapy. Clinical outcome was compared for 2 cohorts: patients who recanalized (n = 46) and patients with persisting large-vessel occlusion (n = 106).

Results: Early recanalization was an independent predictor of a good clinical outcome in only those patients who presented with a severe ischemic stroke (National Institutes of Health Stroke Scale [NIHSS] score >15; P = .017). This was not the case for less severe strokes (NIHSS score ≤ 15) where recanalization did not lead to more patients with functional independence at 90-day follow-up (P = .21).

Conclusions: In this study of acute large-vessel occlusion stroke, we found that clinical outcome following early recanalization was dependent on the patient's pretreatment NIHSS score. A non-negligible proportion of patients with milder strokes did well despite persistent large-vessel occlusion. These results may suggest that in patients who are able to maintain adequate collateral flow despite proximal arterial occlusion, effective adaptive mechanisms are present, which for some patients are long-lasting. This may influence the process of appropriate patient selection for endovascular therapy.

Keywords: Large-vessel occlusion; endovascular treatment; ischemic stroke; recanalization; thrombectomy.

Publication types

  • Comparative Study

MeSH terms

  • Aged
  • Brain Ischemia / diagnosis
  • Brain Ischemia / physiopathology
  • Brain Ischemia / therapy*
  • Cerebrovascular Circulation
  • Denmark
  • Disability Evaluation*
  • Endovascular Procedures* / adverse effects
  • Female
  • Fibrinolytic Agents / administration & dosage*
  • Fibrinolytic Agents / adverse effects
  • Humans
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Prospective Studies
  • Recovery of Function
  • Registries
  • Severity of Illness Index
  • Stroke / diagnosis
  • Stroke / drug therapy*
  • Stroke / physiopathology
  • Thrombectomy* / adverse effects
  • Thrombolytic Therapy* / adverse effects
  • Time Factors
  • Tissue Plasminogen Activator / administration & dosage*
  • Tissue Plasminogen Activator / adverse effects
  • Treatment Outcome


  • Fibrinolytic Agents
  • Tissue Plasminogen Activator