Effect of blood pressure parameters on functional independence in patients with acute ischemic stroke in the first 6 hours after endovascular thrombectomy

Background and purpose Studies have suggested that blood pressure (BP) levels after endovascular thrombectomy (EVT) are correlated with clinical outcomes. The aim of our study was to investigate the effect of BP in different time intervals within the first 24 hours after EVT on functional outcomes. Methods Data of patients who received EVT for acute ischemic stroke at two institutions were reviewed. After EVT, hourly BP data were collected and divided into four time intervals: 1-6 hours, 7-12 hours, 13-18 hours, and 19-24 hours. The mean, maximum, and standard deviation (SD) of BP were calculated and compared with the outcome of interest in patients with successful recanalization. The outcome of interest was functional independence, which was defined as a 3-month modified Rankin Scale score of ≤2. Results Of 224 patients with stroke who received EVT, 166 (74.1%) (mean age 70.2±13.1 years; 49.4% men) achieved successful recanalization and 82 (49.4%) exhibited functional independence. After adjustment for possible confounders, lower mean, maximum, and SD values of systolic and diastolic BP observed in the first 6 hours after EVT were independently associated with functional independence. Furthermore, the area under the receiver operating characteristic curve values observed for BP parameters for outcome prediction in the first 6 hours were the highest across the 24-hour period following EVT. Conclusion In patients with stroke who achieved successful recanalization, the first 6 hours after EVT was the key period influencing the correlation between BP and functional outcome.