Background and Purpose— Acute blood pressure (BP) reduction aimed at attenuation of intracerebral hemorrhage (ICH) expansion might also compromise cerebral blood flow (CBF). We tested the hypothesis that CBF in acute ICH patients is unaffected by BP reduction. Methods— Patients with spontaneous ICH <24 hours after onset and systolic BP > 150 mm Hg were randomly assigned to an intravenous antihypertensive treatment protocol targeting a systolic BP of <150 mm Hg (n=39) or <180 mm Hg (n=36). Patients underwent computed tomography perfusion imaging 2 hours postrandomization. The primary end point was perihematoma relative (relative CBF). Results— Treatment groups were balanced with respect to baseline systolic BP: 182±20 mm Hg (<150 mm Hg target group) versus 184±25 mm Hg (<180 mm Hg target group; P =0.60), and for hematoma volume: 25.6±30.8 versus 26.9±25.2 mL ( P =0.66). Mean systolic BP 2 hours after randomization was significantly lower in the <150 mm Hg target group (140±19 vs 162±12 mm Hg; P <0.001). Perihematoma CBF (38.7±11.9 mL/100 g per minute) was lower than in contralateral homologous regions (44.1±11.1 mL/100 g per minute; P <0.001) in all patients. The primary end point of perihematoma relative CBF in the <150 mm Hg target group (0.86±0.12) was not significantly lower than that in the <180 mm Hg group (0.89±0.09; P =0.19; absolute difference, 0.03; 95% confidence interval −0.018 to 0.078). There was no relationship between the magnitude of BP change and perihematoma relative CBF in the <150 mm Hg ( R =0.00005; 95% confidence interval, −0.001 to 0.001) or <180 mm Hg target groups ( R =0.000; 95% confidence interval, −0.001 to 0.001). Conclusions— Rapid BP lowering after a moderate volume of ICH does not reduce perihematoma CBF. These physiological data indicate that acute BP reduction does not precipitate cerebral ischemia in ICH patients. Clinical Trial Registration Information— URL: http://clinicaltrials.gov . Unique Identifier: NCT00963976.

Background and Purpose— Treatment of acute hypertension after intracerebral hemorrhage (ICH) is controversial. In the context of disrupted cerebral autoregulation, blood pressure (BP) reduction may cause decreased cerebral blood flow (CBF). We used serial computed tomography perfusion to test the hypothesis that CBF remains stable after BP reduction. Methods— Patients recruited within 72 hours of ICH were imaged with computed tomography perfusion before and after BP treatment. Change in perihematoma relative (r) CBF after BP treatment was the primary end point. Results— Twenty patients were imaged with computed tomography perfusion at a median (interquartile range) time from onset of 20.2 (25.7) hours and reimaged 2.1 (0.5) hours later, after BP reduction. Mean systolic BP in treated patients (n=16; 4 untreated as BP<target at baseline) decreased significantly between the first (168±21 mm Hg) and second (141±19 mm Hg; P <0.0001) computed tomography perfusion scans. The primary end point of rCBF was not affected by BP reduction (pretreatment=0.89±0.11; post-treatment=0.87±0.11 mL/100 g per minute; P =0.37). Linear regression showed no relationship between changes in systolic BP and perihematoma rCBF (β=0.001 [−0.002 to 0.003]; P =0.63). Conclusions— CBF remained stable after acute BP reduction, suggesting some preservation of cerebral autoregulation.