Abstract 3563: Ischemic Stroke with Early AM Onset is More Severe but Less Frequent
Background: Diurnal fluctuations in clotting factors, occurrence of thrombosis, and stroke have been reported. We sought to evaluate the distribution of stroke occurrence and differences in stroke characteristics and outcomes in a biracial population.
Methods: Patients presenting to our center with acute ischemic stroke of known symptom onset were identified by retrospective chart review. Patients were grouped into one of four onset periods: 00:01-06:00, 06:01-12:00, 12:01-18:00, and 18:01-00:00. We compared demographics, baseline stroke severity, blood pressure and glucose levels, IV tPA treatment rates, stroke etiology, complications, and early clinical outcomes.
Results: The 244 patients with a known time of onset were included in analyses; the distribution of stroke onset and comparison of other collected variables are demonstrated in the figure and table, respectively. Stroke onset 00:01-06:00 was less frequent, but associated with significantly higher median NIHSS score (p=0.005). Patients with stroke onset 00:01-06:00 were more often African-American, had atherothrombotic mechanisms (large artery or small artery infarctions), received IV tPA, and had reduced frequency of good mRS, though statistical significance was not achieved. Time interval of stroke onset was not an independent predictor of death, good outcome (mRS 0-2), or favorable discharge disposition (home or inpatient rehabilitation).
Discussion: The most severe ischemic strokes occurred in early AM hours, but were less common than stroke onset during other time intervals. A larger sample is required to determine why ischemic stroke is more severe with early AM onset, if blacks are more susceptible to early AM stroke, and if early AM stroke is less responsive to tPA.
- © 2012 by American Heart Association, Inc.