Abstract
This study discusses the association between blood pressure (BP) variability at different time periods within first 24 hours after admission and the functional outcome in acute ischemic stroke (AIS). We observed BP variability within first 24 hours after admission and evaluated the association between BP variability at different time periods (4 am-8 am, 10 am-2 pm, 4 pm-8 pm, 10 pm-2 am) and the functional outcome in AIS. National Institute of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) were applied to evaluate short- (7 days) and long-term functional outcome. The 24 hours after admission and early morning (4 am-8 am) systolic blood pressure (SBP) variability were associated with poor outcome at day 7 (adjusted OR = 1.567, 95% CI = 1.076-2.282; adjusted OR = 1.507, 95% CI = 1.028-2.209, respectively). Compared with the impact of the 24-hour BP variability on long-term functional outcome, the early morning SBP was proved to be a strongly independent predictor for functional outcome at 3 months (adjusted OR = 1.505, 95% CI = 1.053-2.152), 6 months (adjusted OR = 1.560, 95% CI = 1.048-2.226), and 12 months (adjusted OR = 1.689, 95% CI = 1.104-2.584). The BP variability in other time period groups was shown to have no influence on functional outcome. In addition, attempts to explain early morning BP variability with baseline characteristic factors at admission found that baseline SBP is the most influential (2.71%) factor. About 95.87% of the SBP variability in early morning was unexplained. In our study, early morning SBP variability is the strongest independent predictor for functional outcome in (AIS) patients, and baseline SBP after admission should be monitored as a control indicator of early morning SBP variability in the treatment of AIS patients.