To investigate correlation between the day-by-day blood pressure variability within 1 week and the outcomes at 6 months after acute ischemic stroke.

From January 2013 to December 2015, the patients with acute ischemic stroke admitted to hospital were registrated consecutively. Blood pressure was monitored every morning within 7 d after admission and the parameters of blood pressure variability were calculated. They were followed up for 6 months. The outcomes were evaluated according to the modified Rankin scale (mRS). Good outcome was defined as the mRS score 0 to 2. The clinical characteristics, blood pressure and day-by-day blood pressure variability parameters were compared between the good outcome group and the poor outcome group. Multivariable logistic regression analysis was used to determine the correlation between the day-by-day blood pressure variability and the outcomes at 6 months.

A total of 169 patients were enrolled in the study, including 89 (52.7%) with poor outcomes. The day-by-day mean systolic blood pressure (147.1±15.9 mmHg vs. 139.6±19.0 mmHg; t=2.666, P=0.008; 1 mmHg=0.133 kPa), standard deviation of systolic blood pressure (median and interquartile range: 16.5 [13.7-19.4] mmHg vs. 13.4 [10.7-18.3] mmHg; Z=2.909, P=0.004), and maximum-minimum difference of systolic blood pressure (47.0 [38.0-56.0] mmHg vs. 37.0 [29.0-49.0] mmHg; Z=3.634, P<0.001) of the poor outcome group were significantly higher than those of the good outcome group. Multivariate logistic regression analysis showed that the daily increased maximum-minimum difference of systolic blood pressure was an independent risk factor for poor outcome at 6 month after onset (odds ratio, 1.028, 95%confidence interval 1.007-1.050; P=0.008).

Increased day-by-day blood pressure variability was independently associated with the poor outcome after acute ischemic stroke.

Stroke; Brain Ischemia; Blood Pressure; Prognosis; Time Factors