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.
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%).
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%.
"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