Abstract TMP71: Marked Circadian Variation in Number and Type of Hyperacute Strokes During the 24 Hour Day-Night Cycle

• Published in: Stroke (1970) 2020-02, Vol.51 (Suppl_1)
• Main Authors: Khorramian, Eeman, Starkman, Sidney, Sanossian, Nerses, Liebeskind, David, Avila, Gilda, Stratton, Samuel, Eckstein, Mark, Pratt, Franklin, Sharma, Latisha, Restrepo, Lucas, Valdes-Sueiras, Miguel, Kim-Tenser, May, Villablanca, Pablo, Conwit, Robin, Hamilton, Scott, Saver, Jeffrey
• Format: Article
• Language: English
• ISSN: 0039-2499; 1524-4628
• DOI: 10.1161/str.51.suppl_1.TMP71

Abstract only Background: Circadian variations in stroke onset provide critical information for allocation of prehospital and hospital resources in clinical care and clinical trials. Studies of stroke circadian timing have had conflicting findings, and understanding would benefit from analysis confined to patients with defined onset in waking and clearly distinguished ischemic and hemorrhagic stroke subtypes. Methods: We analyzed all patients enrolled in the NIH FAST-MAG phase 3 trial of field-initiated neuroprotective agent in patients with hyperacute stroke within 2h of onset (last known well). Onset times were analyzed in 1h time blocks throughout the 24h day-night cycle. Patient demographic and clinical features, medical history, imaging characteristics, and stroke deficit severity were evaluated for association with onset times. Results: Among 1632 patients, final diagnoses were acute cerebral ischemia in 76.2% and intracranial hemorrhage in 23.7%. Hourly circadian variation in onset is shown in the Figure. Acute cerebral ischemia (ACI) had a unimodal distribution with peak onset at midday (12:00-12:59); intracerebral hemorrhage (ICH) a bimodal distribution with peaks at mid-morning (08:00-08:59) and early evening (18:00-18:59). Events were markedly reduced in early morning, with only 3.4% starting in the 25% of the day between 00:00-05:59. The proportion of events that were hemorrhagic was higher in the first 8h of the day (00:00-07:59) than the remaining 16h, 33.3% vs 22.5%, p=0.006. Both among ACI and ICH patients, vascular risk factors, presenting deficit severity, and initial brain imaging findings were fairly homogenous throughout all day-night time periods. Conclusion: There is marked, more than 10-fold, circadian variation in onset of acute cerebrovascular disease, and circadian variation in the ratio of ischemic to hemorrhagic neurovascular events. These findings can inform resource planning for regional systems of acute stroke care.