Cerebral Perfusion and Blood Pressure Do Not Affect Perihematoma Edema Growth in Acute Intracerebral Hemorrhage

Background and Purpose—The pathogenesis of perihematoma edema in intracerebral hemorrhage (ICH) is unknown but has been hypothesized to be ischemic. In the ICH Acutely Decreasing Arterial Pressure Trial (ICH ADAPT), perihematoma cerebral blood flow (CBF) was reduced but was unaffected by blood pressure (BP) reduction. Using ICH ADAPT data, we tested the hypotheses that edema growth is associated with reduced CBF and lower systolic BP. Methods—Noncontrast computed tomographic scans in patients with ICH were obtained at baseline, 2 hours, and 24 hours after randomization to target systolic BPs of <150 or <180 mm Hg. Computed tomography perfusion imaging was performed at 2 hours, and mean relative CBF was calculated in visibly edematous perihematoma tissue. Edema volumes were measured using a Hounsfield unit threshold of 5 to 23 at each time-point. Results—Patients were randomized at a median (interquartile range) of 7.4 (12.8) hours after onset. Treatment groups (n=34, <150 and n=33, <180 target) were balan...