Abstract 100: Combining Prehospital Neuroprotective Therapy With Post-Hospital Arrival Recanalization Therapies: The FAST-MAG Experience

Abstract

Background: Prehospital neuroprotective therapy aims to preserve penumbral tissue in anticipation of recanalization therapies. We describe the population receiving recanalization treatment upon hospital arrival after enrollment in a prehospital neuroprotective trial. Methods: The Field Administration of Stroke Therapy Magnesium (FAST-MAG) phase 3 clinical trial randomized subjects with stroke symptom onset within 2 hours to prehospital treatment with intravenous magnesium sulfate vs. placebo. Subjects were eligible for all FDA-approved/cleared therapies as concomitant treatment, including intravenous thrombolysis and mechanical neurothrombectomy. Results: Among the 1223 patients with acute cerebral ischemia enrolled in the trial, mean age was 71 [SD 13] , 45% were women, 78% White race, 14% Black race and 21% Hispanic ethnicity. Among the cerebral ischemia patients, 434 [36%] received IV thrombolysis and 72 [6%] received endovascular therapy, including 46 patients who received both IV and endovascular recanalization treatment.. Patients treated with IV TPA, compared to supportive care patients, had more severe deficits on ED arrival [median NIHSS 12.5 vs. 4.0, p<0.0001], were assessed by paramedics earlier [30 vs. 50 minutes, p<0.001], and arrived in the ED earlier [63 vs. 84 minutes, p<0.001], but were of similar age and ethnicity. Those who were taken for endovascular therapy had more severe strokes [NIHSS 16, IQR 9.5-23] but were no different in race-ethnicity or time to evaluation. Conclusions: Concomitant intravenous thrombolysis and endovascular recanalization were administered at high rates in the FAST-MAG study, reflecting expanding reperfusion practice in Los Angeles and Orange Counties during the study period. The FAST-MAG population has a sufficient volume of patients concomitantly treated with recanalization therapy to explore with good power the potential benefit of neuroprotection prior to recanalization therapy.