Abstract 113: The Intracerebral Haemorrhage Acutely Decreasing Arterial Pressure Trial (ICH ADAPT): Final Results.

Background: Acute blood pressure (BP) reduction aimed at attenuation of intracerebral hemorrhage (ICH) expansion might also result in a harmful compromise of cerebral blood flow (CBF) in the region surrounding the hematoma. We tested the hypothesis that CBF in acute ICH patients is affected by BP reduction. Methods: Seventy-five patients with spontaneous ICH with baseline systolic BP>150 mmHg were randomly assigned to an intravenous antihypertensive treatment protocol (labetalol, hydralazine and enalapril) targeting a systolic BP of either <150 mmHg or <180 mmHg within 24 hours of symptom onset. Patients underwent CT perfusion (CTP) imaging 2 hours post-randomization. The primary endpoint was relative CBF (rCBF) within the 1 cm perihematoma region. Results: Treatment groups were balanced with respect to baseline systolic BP: 182±20 mmHg (<150 mmHg target group, n=39) vs. 184±25 mmHg (<180 mmHg target group, n=36, p=0.60), hematoma volume: 25.6±30.8 vs. 26.9±25.2 ml (p=0.66) and median (IQR) time to randomization: 7.8 (13.5) and 8.5 (11.9) h (p=0.94). Mean systolic BP two hours after randomization was significantly lower in the <150 mmHg target group (140±19 vs 162±12 mmHg in the <180 target group, p<0.001). Perihematoma CBF (38.7±11.9 ml/100g/min) was lower than in contralateral homologous regions (44.1±11.1 ml/100g/min, p<0.001) in all patients. The primary endpoint of perihematoma rCBF in the <150 mmHg target group (0.86±0.12) was not significantly lower than that in the <180 mmHg group (0.89±0.09, p=0.19; absolute difference 0.03 95% CI -0.018, 0.078). There was no relationship between the magnitude of the BP change and perihematoma rCBF in the <150 mmHg (R=0.00005, 95% CI -0.001, 0.001) or <180 mmHg target groups (R=0.000, 95% CI -0.001, 0.001). There were no effects on rCBF in patients treated within 6 hours (0.78±0.22 in the <150 mmHg group and 0.88±0.10 in the <180 mmHg group, p=0.08) or in those treated 6-24 hours after onset (0.85±0.21 in the <150 mmHg group and 0.89±0.10 in the <180 mmHg group, p=0.46). Conclusions: Rapid BP lowering following ICH does not reduce perihematoma CBF. These physiological data support the safety of acute and aggressive BP reduction following ICH.