Abstract 33: Cerebral Blood Flow in Leukoaraiosis Regions is Unaffected by Acute Lowering of Blood Pressure in Intracerebral Hemorrhage Patients.

Abstract

Introduction: Leukoariosis(LA) is associated with poor prognosis in intracerebral hemorrhage (ICH) patients. Patients with chronic small vessel ischemic changes may be more vulnerable to decreases in cerebral perfusion, in both LA and perihematoma(PH) regions. We tested the hypotheses that acute blood pressure reduction (BP) in ICH patients is associated with decreased cerebral blood flow (CBF) in areas of LA and the PH region. Methods: In the ICH Acutely Decreasing Arterial Pressure Trial (ICH ADAPT), patients with ICH <24 hours duration were randomized to two systolic BP (SBP) target groups (<150 mmHg vs. <180 mmHg). Computed tomography (CT) perfusion imaging was performed 2 h post-randomization. LA tissue volume was planimetrically measured on the acute non-contrast CT, using Hounsfield Unit thresholds of 15-25. CBF, cerebral blood volume (CBV), and Tmax were measured in the LA regions. Results: Seventy-one patients were included with a mean age of 69.3±11.5 years and median (IQR) baseline NIHSS score of 10(11). LA was present in 74.6% (53/71) and the median volume was 8.5(20.6) ml. LA was associated with older age (70.9± 11.2 vs. 64.8 ±11.6, p=0.05) and larger ICH volumes (19.52(29.78) vs. 9.52(16.02) ml, p=0.007). Mean CBF in LA regions (32.5±13.5) was similar to that in normal appearing white matter (35.6±12.1, p=0.3). Despite a significant drop in SBP between aggressive (36.25(40) mmHg) and conservative (18.5(29) mmHg, p=0.01) treatment groups, relative CBF (rCBF) in LA regions was unaffected (0.88±0.1 vs. 0.89±0.09, p=0.6). Similarly, aggressive BP treatment did not affect relative CBV (0.83±0.16 vs. 0.82± 0.15, p=0.8) or Tmax (7.3±3.2 s vs. 6.5 ±2.4 s, p=0.3). The rCBF in the PH regions in patients’ with/without LA was similar (0.88±0.09 vs. 0.86±0.1, p=0.5). There was a trend to worse functional outcome at 90 days, measured with the modified Rankin Scale in patients with LA (4(4) vs. 2(1), p=0.06). Conclusion: LA is associated with larger baseline ICH volumes, but no differences in perihematoma CBF or the response to BP reduction. CBF in LA tissue is also unaffected by BP reduction. These data do not support a less aggressive approach to BP reduction in elderly patients with imaging evidence of chronic small vessel ischemia.