Background: Data on the correlation between blood pressure (BP) on admission and clinical outcome in patients with acute stroke are conflicting. The aims of the present study in consecutive patients with acute ischemic stroke were to evaluate: (a) the relationship between systolic or diastolic BP on admission and mortality at 3 months; (b) the role of carotid artery disease ipsilateral to the index stroke on this relationship.
Methods: Consecutive patients admitted to four Italian hospitals with objectively diagnosed ischemic stroke were included in this prospective study.
Results: A total of 1467 patients (mean age 72.6+/-13.2 years; males 53.3%) with acute ischemic stroke were evaluated. At 3 months, 13 patients were lost at follow-up and 133 had died (9.2%). In patients with systolic BP <140mmHg, mortality was 11% (40/362), in patients with systolic BP between 140 and 179mmHg 8.3% (68/823) and in patients with systolic BP >or=180mmHg 9.2% (25/269). Patients with systolic BP <140mmHg were more likely to die within 90 days (OR 3.4; 95% CI 1.4-8.5, p=0.008, after adjusting for other risk factors) when compared to those with systolic BP between 140 and 179mmHg (reference group with OR=1.0). Systolic BP >or=180mmHg was not associated with increased mortality (OR 0.4; 95% CI 0.1-1.3, p=0.13). Two-hundred and thirty patients out of 1278 with anterior circulation stroke had a stenosis (>or=50% on ultrasonography) or an occlusion of the internal carotid ipsilateral to the index stroke. At 3 months, 29 patients had died (12.7%). In patients with systolic BP <140mmHg, mortality was 20.4% (11/54), in those with systolic BP between 140 and 179mmHg 13.0% (16/123) and in those with systolic BP >or=180mmHg 3.9% (2/51). Patients with systolic BP >or=180mmHg were less likely to die within 90 days (OR 0.1; 95% CI 0.0-0.5, p=0.022 after adjusting for other risk factors) compared to those with systolic BP between 140 and 179mmHg. Systolic BP <140mmHg was not associated with increased mortality (OR 6.3; 95% CI 0.8-48.0, p=0.08).
Conclusions: In the overall population, low BP was an independent risk factor for mortality. In patients with stenosis >/=50% or occlusion of the carotid ipsilateral to the index stroke, high BP was associated with a lower mortality at 3 months.