Abstract Body: Background and Aims

Diffusion-Weighted Imaging (DWI) lesions have been demonstrated in sub-acute Intracerebral Hemorrhage (ICH) patients, suggesting ischemic injury which may be related to Blood Pressure (BP) reduction. We conducted a randomized trial to test the hypothesis that acute BP lowering is associated with DWI lesions after ICH.

Methods
ICH ADAPT II (NCT02281838) was a multicentre randomized open-label, blinded-endpoint trial. ICH patients were randomized to a systolic BP (SBP) target of <140mmHg or <180mmHg within 6 hours of onset. The primary outcome was DWI lesion incidence assessed on 48h MRI.

Results
A total of 162 ICH patients were randomized at a median of 3.17 (IQR 2.27) hours after onset. DWI was obtained at 51.6 (27.0) hours in 79 patients (age 72 (21) years with ICH volume of 11.2 (range 0.5-122.2) ml. Mean baseline SBP was 183±22 mmHg in the <140 and 181±28 mmHg in the <180 target groups. One hour after randomization, mean SBP was 144±22 mmHg in the<140 group and 167±23 mmHg in the <180 group. (adjusted mean difference 12.7 [2.5, 22.8] mmHg, p=0.0146). Mean SBP remained lower over the 48-hour period after randomization in the <140 group (adjusted mean difference for period 12.6 [11.2, 13.9] mmHg, p<0.0001).

DWI lesions were detected in 12/42 (28.6%) patients in the <140mmHg group and 14/37 (37.8%) in the <180mmHg group (OR=0.65 [0.10, 4.21], p=0.237). Multivariate logistic regression indicated that ischemic lesions were predicted by baseline ICH volume (beta=0.0487 [0.018,0.080], p=0.002), but not SBP treatment. The median number of DWI lesions (1(0) vs 1(1.75), p=0.385) and total DWI lesion volume (0.1 (0.1) ml vs 0.34 (0.76) ml, p=0.198) was not different in the <140mmHg and <180mmHg groups. One patient with a 29.5 ml baseline ICH volume (35 ml at 24 hours) in the <140mmHg group developed extensive bilateral internal borderzone DWI changes (volume=41.3 ml) following SBP reduction from 223 mmHg to 187 mmHg at 1 hour.

Conclusions
We found no evidence that low volume DWI lesions in ICH patients are precipitated or aggravated by antihypertensive therapy in acute ICH. Further MRI studies in acute ICH are required to determine predicators of less common large volume ischemic lesions.