Effects of Early Intensive Blood Pressure-Lowering Treatment on the Growth of Hematoma and Perihematomal Edema in Acute Intracerebral Hemorrhage: The intensive blood pressure reduction in acute cérébral haemorrhage trial (INTERACT)

Background and Purpose-The Intensive Blood Pressure Reduction In Acute cérébral Haemorrhage Trial (INTERACT) study suggests that early intensive blood pressure (BP) lowering can attenuate hematoma growth at 24 hours after intracerebral hemorrhage. The present analyses aimed to determine the effects of treatment on hematoma and perihematomal edema over 72 hours. Methods-INTERACT included 404 patients with CT-confirmed intracerebral hemorrhage, elevated systolic BP (150 to 220 mm Hg), and capacity to start BP-lowering treatment within 6 hours of intracerebral hemorrhage. Patients were randomly assigned to an intensive (target systolic BP 140 mmHg) or standard guideline-based management of BP (target systolic BP 180 mm Hg) using routine intravenous agents. Baseline and repeat CTs (24 and 72 hours) were performed using standardized techniques with digital images analyzed centrally. Outcomes were increases in hematoma and perihematomal edema volumes over 72 hours. Results-Overall, 296 patients had all 3 CT scans available for the hematoma and 270 for the edema analyses. Mean systolic BP was 11.7 mm Hg lower in the intensive group than in the guideline group during 1 to 24 hours. Adjusted mean absolute increases in hematoma volumes (mL) at 24 and 72 hours were 2.40 and 0.15 in the guideline group compared with-0.74 and-2.31 in the intensive group, respectively, an overall difference of 2.80 (95% CI, 1.04 to 4.56; P=0.002). Adjusted mean absolute increases in edema volumes (mL) at 24 and 72 hours were 6.27 and 10.02 in the guideline group compared with 4.19 and 7.34 in the intensive group, respectively, for an overall difference of 2.38 (95% CI,-0.45 to 5.22; P=0.10). Conclusion-Early intensive BP-lowering treatment attenuated hematoma growth over 72 hours in intracerebral hemorrhage. There were no appreciable effects on perihematomal edema.