No abstract

Background: Ischemic and hemorrhagic stroke onset exhibit is known to exhibit diurnal variation throughout the 24-hour cycle. But whether this variation differs on weekdays compared with weekends/holidays has not been well delineated. Methods: We evaluated consecutive patients with acute cerebral ischemia [(ACI), including ischemic stroke (IS) and transient ischemic attack (TIA)] and intraparenchymal hemorrhage (IPH) enrolled during ambulance transport to 60 receiving stroke centers in the NIH FAST-MAG trial. Enrollment required onset within the prior 2 hours, excluding confounding by wake-up and unwitnessed onset strokes. The patterns of time of onset were analyzed: 1) hourly, 2) in 4-hour increments, and 3) daytime (08:00-19:59) vs. night-time (20:00-07:59). Diurnal variation in presenting demographic/clinical features were assessed using ANOVA, Kruskal-Wallis, t-tests, and Wilcoxon Rank-Sum. Results: Among 1615 patients (1202 enrolled on weekdays and 442 on weekends/holidays), 64% had IS, 12.5% TIA, and 23.5% IPH. ACI patients had different patterns of onset time (Figure). During weekdays, a broad plateau of highest rates of onset occurred 09:00-22:00. Conversely, during weekends/holidays, a unimodal peak was observed between 14:00-16:00. In contrast, patterns of onset time in IPH patients were broadly similar, with bimodal peaks on both weekdays and weekends/holidays. However, the first peak occurred earlier on weekdays (09:00-12:00 vs. 11:00-13:00), with the second peak occurring within 17:00-20:00 in both groups. Conclusion: Acute cerebral ischemia shows marked, and intraparenchymal hemorrhage minor, pattern differences in onset times on weekdays vs. weekends/holidays, likely related to variations in times of greater physical activity and stress. These findings can inform EMS resource allocation to stroke, aligned with weekday vs. weekend/holiday onset patterns.

Background: To emphasize treatment speed for time-sensitive conditions, emergency medicine has developed not only the concept of the golden hour, but also the platinum half-hour. Patients with acute stroke treated within the first half-hour of onset have not been previously characterized. Methods: In this cohort study, we analyzed patients enrolled in the FAST-MAG (Field Administration of Stroke Therapy–Magnesium) trial, testing paramedic prehospital start of neuroprotective agent ≤2 hours of onset. The features of all acute cerebral ischemia, and intracranial hemorrhage patients with treatment starting at ≤30 m of last known well were compared with later-treated patients. Results: Among 1680 patients, 203 (12.1%) received study agents within 30 minutes of last known well. Among platinum half-hour patients, median onset-to-treatment time was 28 minutes (interquartile range, 25–30), and final diagnoses were acute cerebral ischemia in 71.8% (ischemic stroke, 61.5%, TIA 10.3%); intracranial hemorrhage in 26.1%; and mimic in 2.5%. Clinical features among platinum half-hour patients were largely similar to later-treated patients and included age 69 (interquartile range, 57–79), 44.8% women, prehospital Los Angeles Motor Scale median 4 (3–5), and early-postarrival National Institutes of Health Stroke Scale deficit 8 (interquartile range, 3–18). Platinum half-hour acute cerebral ischemia patients did have more severe prehospital motor deficits and younger age; platinum half-hour intracranial hemorrhage patients had more severe motor deficits, were more often female, and less often of Hispanic ethnicity. Outcomes at 3 m in platinum half-hour patients were comparable to later-treated patients and included freedom-from-disability (modified Rankin Scale score, 0–1) in 35.5%, functional independence (modified Rankin Scale score, 0–2) in 53.2%, and mortality in 17.7%. Conclusions: Prehospital initiation permits treatment start within the platinum half-hour after last known well in a substantial proportion of acute ischemic and hemorrhagic stroke patients, accounting for more than 1 in 10 enrolled in a multicenter trial. Hyperacute platinum half-hour patients were largely similar to later-treated patients and are an attainable target for treatment in prehospital stroke trials.