Introduction: Because “time is brain,” acute stroke trials are increasingly migrating to the prehospital setting. However, some study therapies are ill-suited for paramedic, prehospital delivery, including fibrinolytics, endovascular therapies, and surgical interventions. Best scientific and regulatory practice does not permit one patient to participate in two different therapeutic trials simultaneously. The potential reduction in enrollment in post-arrival trials due to earlier recruitment in a prehospital trial has not been well delineated.
Methods: We analyzed all patients recruited into acute stroke trials at an academic medical center (AMC) from Jan 2005 - Dec 2012. Throughout this period, the AMC was participating in a prehospital treatment trial (NIH FAST-MAG trial), as well as diverse concurrent post-arrival acute trials.
Results: During the 96 month study period, in addition to the prehospital trial, the AMC participated in 26 other acute, post-arrival stroke trials, 25 for ischemic stroke and 1 for intracerebral hemorrhage. Length of participation in each post-arrival trial varied, but at all times throughout the study period, the AMC was recruiting for at least 3 concurrent post-arrival acute trials. During this time, a total of 200 patients were enrolled in acute stroke trials, including 98 (49%) in FAST-MAG and 102 (51%) in concurrent, post-arrival acute trials. Among the patients enrolled in FAST-MAG, 67% were not eligible for any concurrent trial. Among the 33% eligible for a concurrent trial, 15% were eligible for 1, 7% for 2, 7% for 3, and 3% for 4. Of the 134 patients eligible for post-arrival trials, 102 (76%) were enrolled in post-arrival trials and 32 (24%) in FAST-MAG. Leading reasons that FAST-MAG patients were ineligible for post-arrival trials included: NIHSS too low (23.4%), intracranial hemorrhage (17.9%), deficit resolved to TIA (9.2%), IV tPA used in standard management (9.0%), NIHSS too high (7.1%), and age too high (5.2%).
Conclusions: A prehospital hyperacute stroke trial with wide entry criteria reduced only modestly, by one-fourth, enrollment into concurrently active, post-arrival stroke trials. Simultaneous performance of prehospital and ED-based acute stroke trials in research networks is highly feasible.