A New DAWN for Treatment of Stroke

Interview with Jeff Saver, MD of UCLA Stroke program describes the new era of "Tissue" based selection of treatment for acute ischemic stroke patients

  1. Editorial introducing DAWN Trial by Werner Hacke
  2. DAWN Trial PDF

Clear, Randomized Data Supporting Endovascular Therapy for Acute Ischemic Stroke Has Arrived. Finally!!

A Randomized Trial of Intraarterial Treatment for Acute Ischemic Stroke

Endovascular Therapy for Ischemic Stroke with Perfusion-Imaging Selection

Randomized Assessment of Rapid Endovascular Treatment of Ischemic Stroke

Thrombectomy within 8 Hours after Symptom Onset in Ischemic Stroke

Stent-Retriever Thrombectomy after Intravenous t-PA vs. t-PA Alone in Stroke

2015 American Heart Association/American Stroke Association Focused Update of the 2013 Guidelines for the Early Management of Patients With Acute Ischemic Stroke Regarding Endovascular Treatment

Evidence supporting IV-tPA treatment up to 4.5 hours of last known well:

  1. An Analysis of all tPA trials to date (US and Europe) support benefits to therapy beyond 3 hours but with diminishing returns over time.
  2. ECASS-3 studied tPA treatments in patients presenting within 3-4.5 hours of symptom onset with a few modifications in inclusion/exclusion criteria and found benefit in tPA vs. placebo without an excess in death or symptomatic hemorrhages. This led to approval for treatment within the EU for tPA in this time-frame using study criteria.
  3. A registry was required by the EU following approval for IV-tPA for acute ischemic stroke within 4.5 hrs. Results were published as part of the SITS-ISTR Study which demonstrated that in over 23,000 patients treated, 2376 of which were in 3-4.5 hour time window, ~ 60% were independent at 3 months with a low symptomatic hemorrhage rate (2%).
  4. US data from the AHA/ASA Get with the Guidelines Stroke data set showed that in over 58,000 patients treated with IV-tPA in the 4.5 hour time window, 1/3 of patients were independent in ambulation and 39% were able to return home with a symptomatic hemorrhage rate of only 4.9%.
  5. The AHA/ASA Science advisory in 2009 and ASA Guidelines from 2013 support the use of IV-tPA within the 3-4.5 hour time-windo with a Class 1, Level B recommendation.
  6. The American Academy of Emergency Medicine Position Statement from 2012 supports use of IV-tPA in the 3-4.5 hour treatment-window with a Class A Level of recommendation stating "Tissue Plasminogen Activator 3 to 4.5 Hours After Acute Ischemic Stroke Improves Outcome Without Increasing Morbidity".

Use of CTA in Acute Ischemic Stroke

  • "An important aspect of the workup of patients with stroke, TIA, or suspected cerebrovascular disease is imaging of intracranial vasculature. The majority of large strokes are caused by occlusion in ≥1 large vessel. Large-vessel occlusion is a devastating condition."ASA Guidelines 2013
  • "Helical CT angiography (CTA) provides a means to rapidly and noninvasively evaluate the intracranial and extracranial vasculature in acute, subacute, and chronic stroke settings and thus to provide potentially important information about the presence of vessel occlusions or stenoses. The accuracy of CTA for evaluation of large-vessel intracranial stenoses and occlusions is very high..."ASA Guidelines 2013
  • "Noninvasive imaging by means of CTA or MRA of the intracranial vasculature is recommended to exclude the presence of proximal intracranial stenosis and/or occlusion (Class I; Level of Evidence A) and should be obtained when knowledge of intracranial steno-occlusive disease will alter management."ASA Guidelines 2013
  • Review: Role of imaging in current acute ischemic stroke workflow for endovascular therapy.
  • NWSS CTA Protocol for Acute Stroke
  • The Massachusetts General Hospital acute stroke imaging algorithm: an experience and evidence based approach
  • Importance of Large Vessel Occlusion (LVO) in Acute Stroke

  • Up to 46% of patients presenting with acute stroke have LVO on CTA. Smith, W Stroke. 2009 Dec; 40(12): 3834–3840.
  • Presence of LVO on CTA is associated with a 7 fold increased odds of unfavorable outcome or death. Nedeltchev K Stroke. 2007 Sep;38(9):2531-5. Epub 2007 Aug 2.
  • Site of Occlusion Predicts Response to IV Thrombolysis.

  • Recanalization rates with IV-tPA based on site of occlusion: M2-MCA 44%; M1-MCA 30%; Tandem MCA/ICA 27%; Terminal ICA 5.9%; Basilar artery 30%. Saqqur,M Stroke. 2007 Sep;38(9):948-954.
  • Favorable Outcomes (mRS 0-1) with IV-tPA based on site of occlusion: M2-MCA 52%; M1-MCA 25%; Tandem MCA/ICA 21%; Terminal ICA 18%; Basilar artery 25%. Saqqur,M Stroke. 2007 Sep;38(9):948-954.