Short-term outcome after ischemic stroke and 24-h blood pressure variability: association and predictors

To examine the association between blood pressure (BP) variability measured within 24 h after admission for acute ischemic stroke and functional outcome 30 days after stroke onset and to find outcome predictors. A total of 174 patients were included in this retrospective study. Supine BP was measured every 4 h during the first 24 h after admission. The functional outcome was assessed using the modified Rankin Scale. BP parameters including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP) were examined. A set of six variability indices was calculated, including standard deviation (SD), successive variation (SV), difference between maximum and minimum value (DMM), and maximal successive change (MSC). Patients with high SBP or PP variability measures were significantly more likely to develop an unfavorable outcome. All PP variability indices displayed the highest correlations with the outcome. This association was confirmed in logistic regression analysis, both in univariable model and a model adjusted to the baseline National Institute of Health Stroke Scale score and mean BP (the OR for an unfavorable outcome following a 10-mmHg increase in SD, SV, MSC, and DMM parameters was in the interval 1.4-2.7,p < 0.05). Following receiver operating characteristic analysis, the PP parameters yielded area under the curve (AUC) values between 0.654 and 0.666,p < 0.005. Thus, in the acute phase of ischemic stroke, the SD and MSC indices of PP variability during the first 24 h after admission were robustly associated with patients' 30-day outcomes and served as predictors of unfavorable outcomes with thresholds of 14 and 26 mmHg, respectively.