Abstract W P258: Magnitude of Acute Blood Pressure Decrease Does Not Predict the Presence of Diffusion-Restricted Lesions in Patients With Intracerebral Hemorrhage

Introduction: Recent studies have shown an association between aggressive blood pressure (BP) reduction in intracerebral hemorrhage (ICH) and the presence of acute ischemic lesions on diffusion-weighted MR imaging (DWI). However, these findings were based on admission or nadir BP measurements. We tested the hypothesis that the magnitude of acute BP decrease is associated with DWI lesions Methods: We conducted a retrospective analysis of 51 ICH patients who underwent MR imaging with DWI sequences. DWI lesion volumes were measured using planimetric methods. Systolic BP (SBP), diastolic (DBP), and MAP were recorded at baseline, 1,2,6,12, and 24h. Weighted average BP was calculated as the area under the curve of BP measures over 24h. High SBP, low SBP, and high MAP load (calculated as the fraction of time spent >180, <150, or >130 mmHg, respectively) were also determined. Results: Median (IQR) time to MRI was 3.0(4.5) days. Seven patients (14%) demonstrated DWI lesions. Mean DWI volume was 0.97±0.62 ml; 50% of lesions were cortical and 60% were ipsilateral to the hematoma. Median hematoma volume (ml) (16.0(45) vs. 10.5(22), p=0.23) and leukoaraoisis volume (1.8(5.5) vs. 5.6(15.9), p=0.25) did not differ between DWI+ and DWI- patients, respectively. Mean baseline SBP was similar in both groups (171±28 vs. 161.9±28), p=0.44). Weighted mean average SBP in DWI+ patients (158.3±7.5 ml) was similar to that in DWI- patients (143.6±20.4, p=0.21) as was the weighted mean average MAP (102.8±4.3 vs. 98.4±16, p=0.12, respectively). The median 24h decrease in SBP in DWI+ (-20.3 (40.1) mmHg) was similar to that in DWI- patients (-12.7(21), p=0.91). Similarly, high SBP load (5.8% vs. 7.4%, p=0.82), low SBP load (22.5% vs. 60.0%, p=0.16) and high MAP load (6.3% vs. 4.2%,p=0.71) did not differ between groups. Treatment with IV antihypertensive agents was similar in DWI+ (28.6%) and DWI- (29.5%) patients (p=1.00). Conclusions: The magnitude of BP decrease, IV treatment and BP load over 24 hours are not predictive of sub-acute ischemic lesion development. These data do not support a hemodynamic mechanism of DWI lesion formation.