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Background: Transient elevated blood pressure (BP) is frequent in patients presenting with acute ischemic stroke. The pathophysiology of this response is not clear and its effect on clinical outcome has shown contradictory results. Some studies have suggested that BP elevation may represent a protective response to enhance perfusion in ischemic brain tissue. In this study, we aimed to explore the association between elevated admission BP and stroke severity in the acute phase of ischemic stroke. If it is true that elevated BP represents a protective response in acute ischemia, we expected an inverse association between elevated BP and admission stroke severity, and a positive association between elevated BP and complete neurological recovery within 24 h and/or favorable short-term outcome. Methods: Patients with ischemic stroke with hospital admission <6 h after symptom onset were prospectively included in a stroke registry (Bergen NORSTROKE Registry). BP was measured immediately after admission in all patients. Elevated BP was defined as systolic BP ≥140 mm Hg or diastolic BP ≥90 mm Hg. The National Institutes of Health Stroke Scale (NIHSS) was used to assess stroke severity upon admission. Mild stroke was defined as NIHSS score <8, moderate stroke as NIHSS score 8-14, and severe stroke as NIHSS score ≥15. Complete neurological recovery (CNR) was defined as no persistent ischemic stroke symptoms at 24 h after admission. Favorable short-term outcome was defined as a modified Rankin Scale score of 0 or 1 at day 7. Results: A total of 749 patients with ischemic stroke were included, of which 621 patients (82.9%) presented with elevated BP. Elevated BP was independently associated with mild stroke (odds ratio, OR: 2.12; 95% CI: 1.39-3.24; p < 0.001), whereas lack of elevated BP was independently associated with severe stroke (OR: 0.41; 95% CI: 0.25-0.68; p < 0.001). There was a nonsignificant association between elevated BP and CNR (OR: 2.11; 95% CI: 0.96-4.68; p = 0.063), yet no association between elevated BP and favorable short-term outcome (OR: 0.97; 95% CI: 0.59-1.59; p = 0.906) when adjusted for confounders. Conclusion: Our study showed an inverse association between elevated BP and stroke severity on admission, where elevated BP was associated with mild stroke and lack of elevated BP was associated with severe stroke. This could be explained by a protective effect of elevated BP in the acute phase of ischemic stroke, although the absence of association between elevated BP and favorable outcome argues against this hypothesis.

Background and Purpose—The NOR-SASS (Norwegian Sonothrombolysis in Acute Stroke Study) aimed to assess effect and safety of contrast-enhanced ultrasound treatment in an unselected acute ischemic stroke population.Methods—Patients treated with intravenous thrombolysis within 4.5 hours after symptom onset were randomized 1:1 to either contrast-enhanced sonothrombolysis (CEST) or sham CEST. A visible arterial occlusion on baseline computed tomography angiography was not a prerequisite for inclusion. Pulse-wave 2 MHz ultrasound was given for 1 hour and contrast (SonoVue) as an infusion for ≈30 minutes. Magnetic resonance imaging and angiography were performed after 24 to 36 hours. Primary study end points were neurological improvement at 24 hours defined as National Institutes of Health Stroke Scale score 0 or reduction of ≥4 National Institutes of Health Stroke Scale points compared with baseline National Institutes of Health Stroke Scale and favorable functional outcome at 90 days defined as modified Rankin scale score 0 to 1.Results—A total of 183 patients were randomly assigned to either CEST (93 patient) or sham CEST (90 patients). The rates of symptomatic intracerebral hemorrhage, asymptomatic intracerebral hemorrhage, or mortality were not increased in the CEST group. Neurological improvement at 24 hours and functional outcome at 90 days was similar in the 2 groups both in the intention-to-treat analysis and in the per-protocol analysis.Conclusions—CEST is safe among unselected ischemic stroke patients with or without a visible occlusion on computed tomography angiography and with varying grades of clinical severity. There was, however, statistically no significant clinical effect of sonothrombolysis in this prematurely stopped trial.Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01949961.