Abstract TP261: Beyond the Golden Hour: Treating Acute Stroke in the Platinum 30 Minutes

Abstract

Background: As hemorrhagic and ischemic strokes progress, acute stroke therapy is time dependent. To emphasize treatment speed for time-sensitive conditions, emergency medicine has developed not only the concept of the “golden hour,” but also the “platinum thirty”. Acute stroke patients treated within the first half-hour of onset have not been previously characterized. Methods: We analyzed all patients with acute stroke symptoms enrolled in the multicenter NIH-funded FAST-MAG trial, testing paramedic prehospital start of neuroprotective agent within 2h of onset. The frequency, demographic, clinical, and outcome features of patients with treatment start within the platinum 30m were compared with later treated patients. Results: Among the 1700 enrolled patients, 180 (10.6%) received study agent within 30 minutes of last known well (LKW). In these platinum-30 patients, final diagnoses were: acute cerebral ischemia in 70.0% (ischemic stroke 59.4%, TIA 10.6%); intracranial hemorrhage in 26.7%; and mimic in 2.8%, similar to the overall study population. Mean age was 68.3 (±13.2) years, 46.1% were women, initial deficit in the field on the Los Angeles Motor Scale was mean 4.1 (±1.2) and early-post-arrival NIHSS deficit was 11.3 (±10.5). Time from LKW to 911 call was median 4m (IQR 2-6); from LKW to paramedic evaluation 10m (IQR 7-12); from LKW to study drug start 27m (IQR 25-29); and from LKW to ED arrival 36m (IQR 31-41). Outcomes at 3 months included freedom from disability (mRS 0-1) in 35.0%, functional independence (mRS 0-2) in 53.3%, and mortality in 17.2%. Demographic, medical history, presenting deficit severity, and 3m outcomes among the platinum-30 patients were largely similar to the 1415 patients treated between 31-120m after onset. Conclusions: Paramedic prehospital initiation of neuroprotection study agent permits treatment start within the platinum first 30 minutes in a substantial proportion of acute ischemic and hemorrhagic stroke patients, accounting for more than 1 in 10 patients enrolled in a multicenter trial. Hyperacute, <30m patients activated the 911 system sooner after onset but were otherwise similar to later patients and are a treatable target in prehospital stroke trials.