Richard Jackson, MD
Leira and Muir evaluated the EXTEND trial in comparison to previous trials of IV thrombolysis in the >4.5 hour window, including the DIAS trials, DEDAS, EPITHET, and the more recent WAKE-UP trial. The latter trials were all MRI/MR-Perfusion based evaluation except WAKE-UP, which was DWI/FLAIR, in contrast to EXTEND, which was CT/CT-Perfusion.
EXTEND included patients with NIHSS 4-26 with a viable tissue ratio of 1.2 or <10 mL difference and <70 mL core and was terminated prematurely with the release of the DEFUSE-3 data due to the possible eligibility of some of the trial population for thrombectomy with the inclusion of approximately 70% of patients with a large vessel occlusion and median NIHSS>12.
In EXTEND, a higher proportion of patients had recanalization, major early neurologic improvement, independent recovery mRS 0-2 at 90 days, but an increased rate of symptomatic ICH (6.2% vs 0.9%). The conclusion was that the trial “consolidates the concept of determining treatment eligibility based on physiological imaging rather than noncontrast CT and the clock” and that “these advances clearly expand the options for intravenous thrombolysis for late arrivals and strokes of uncertain time of onset.”
I was present and excited at the delivery of the results of the trial at the International Stroke Conference 2019. The question for all of us stroke directors creating protocols is, “Is it time?”
