Background: The clinical impact of blood pressure (BP) and of antihypertensive therapy (AHT) in acute ischemic stroke remains uncertain.
Methods: We reviewed the charts of patients admitted to the Montreal General Hospital between April 1, 2002 and October 15, 2005. Ischemic stroke was considered severe if the Canadian Neurological Scale at presentation was < or =7. Poor outcome at 10 days after onset was defined as a modified Rankin Scale >3. Acute change in BP was defined as the percent difference between the mean 24-hour mean arterial pressure (MAP) and the baseline MAP. AHT was considered present if administered > or =5 days during the first week after stroke onset. The association between predictors and outcome was assessed using unconditional multivariable logistic regression. Covariates used included age, stroke severity, diabetes mellitus, coronary artery disease, atrial fibrillation, premorbid hypertension and hyperlipidemia.
Results: Three hundred and sixty-four patients were included. Compared to patients with intermediate baseline BP, those with a MAP >130 mm Hg [OR = 2.47 (95% CI, 1.04-5.85)] or a MAP <90 mm Hg [OR = 2.94 (95% CI, 1.28-6.77)] were found to have an increased risk of poor outcome after covariate adjustment. A 15% increase in MAP was associated with an increased risk of poor outcome [OR = 5.34 (95% CI, 1.18-24.3)] while AHT in the first week after stroke onset was found to result in a decreased risk [OR = 0.39 (95% CI, 0.17-0.90)]. However, neither of these findings remained significant after adjustment for the described covariates.
Conclusions: Both high and low MAP at presentation are associated with worse short-term outcome after ischemic stroke.