June 3, 2019

Background: Despite the lack of replication of the NINDS & ECASS-3 trials, guidelines recommend the use of tPA in the ≤4.5hr window after the onset of symptoms of acute ischemic stroke [2]. These recommendations used non-contrast computed tomography (NCHCT) for the selection of patients.  More recent endovascular studies have shown that perfusion-based imaging can show potential viable brain tissue beyond the 4.5 hour mark in patients with large vessel occlusions and result in good neurologic outcomes.  This advance has prompted investigators to look at perfusion-based technology to identify a larger cohort of patients without large vessel occlusion that may be candidates for systemic thrombolysis.  One of the big fears in stroke management is the concept of indication creep: finding more uses for a medication or product without strong evidence to support its use. The bigger question is, does this increase in use help the company’s bottom line or the patient? It is no wonder physicians are skeptical of industry sponsored trials, as we sometimes question the motives behind the study.  Now we have another industry sponsored trial: EXTEND. In this trial.