Recanalization Modulates Association Between Blood Pressure and Functional Outcome in Acute Ischemic Stroke.

Abstract

Historical stroke cohorts reported a U- or J-shaped relationship between blood pressure (BP) and clinical outcome. However, these studies predated current revascularization strategies, disregarding the recanalization state of the affected arterial territory. We aimed to investigate the relationship between BP in the first 24 hours after ischemic stroke and clinical outcome in patients submitted to intravenous or intra-arterial recanalization treatments. Consecutive patients with acute stroke treated with intravenous thrombolysis or intra-arterial therapies were enrolled in a retrospective cohort study. BP was measured on regular intervals throughout day and night during the first 24 hours after stroke onset. The mean systolic BP and diastolic BP during the first 24 hours post stroke were calculated. Recanalization was assessed at 6 hours by transcranial color-coded Doppler, angiography, or angio-computed tomography. Functional outcome was assessed at 3 months by modified Rankin Scale. Linear and quadratic multivariate regression models were performed to determine associations between BP and functional outcome for the whole population and recanalyzed and nonrecanalyzed patients. We included 674 patients; mean age was 73.28 (SD, 11.50) years. Arterial recanalization was documented in 355 (52.70%) patients. In multivariate analyses, systolic BP and diastolic BP in the first 24 hours post stroke show a J-shaped relationship with functional outcome in the total population and in the nonrecanalyzed patients. Recanalyzed patients show a linear association with functional outcome (systolic BP: odds ratio, 1.015; 95% confidence interval, 1.007-1.024; P=0.001; R(2) change=0.001; P=0.412 and diastolic BP: odds ratio, 1.019; 95% confidence interval, 1.004-1.033; P=0.012; R(2) change<0.001; P=0.635). Systemic BP in the first 24 hours after ischemic stroke influences 3-month clinical outcome. This association is dependent on the revascularization status.