The association between blood pressure variability and perihematomal edema after spontaneous intracerebral hemorrhage.

Background: Perihematomal edema (PHE) after spontaneous intracerebral hemorrhage (sICH) is associated with clinical deterioration, but the etiology of PHE development is only partly understood. Aims: We aimed to investigate the association between systemic blood pressure (BP) variability (BPV) and formation of PHE. Methods: From a multicenter prospective observational study, we selected patients with sICH who underwent 3T brain MRI within 21 days after sICH, and had at least 5 BP measurements available in the first week after sICH. Primary outcome was the association between coefficient of variation (CV) of systolic BP (SBP) and edema extension distance (EED) using multivariable linear regression, adjusting for age, sex, ICH volume and timing of the MRI. In addition, we investigated the associations of mean SBP, mean arterial pressure (MAP), their CVs with EED and absolute and relative PHE volume. Results: We included 92 patients (mean age 64 years; 74% men; median ICH volume 16.8 mL (IQR 6.6-36.0), median PHE volume 22.5 mL (IQR 10.2-41.4). Median time between symptom onset and MRI was 6 days (IQR 4-11), median number of BP measurements was 25 (IQR 18-30). Log-transformed CV of SBP was not associated with EED (B = 0.050, 95%-CI -0.186 to 0.286, p = 0.673). Furthermore, we found no association between mean SBP, mean and CV of MAP and EED, nor between mean SBP, mean MAP or their CVs and absolute or relative PHE. Discussion: Our results do not support a contributing role for BPV on PHE, suggesting mechanisms other than hydrostatic pressure such as inflammatory processes, may play a more important role.

Cerebral small vessel disease and perihematomal edema formation in spontaneous intracerebral hemorrhage.

Objective: Blood-brain barrier (BBB) dysfunction is implicated in the pathophysiology of cerebral small vessel disease (cSVD)-related intracerebral hemorrhage (ICH). The formation of perihematomal edema (PHE) is presumed to reflect acute BBB permeability following ICH. We aimed to assess the association between cSVD burden and PHE formation in patients with spontaneous ICH. Methods: We selected patients with spontaneous ICH who underwent 3T MRI imaging within 21 days after symptom onset from a prospective observational multicenter cohort study. We rated markers of cSVD (white matter hyperintensities, enlarged perivascular spaces, lacunes and cerebral microbleeds) and calculated the composite score as a measure of the total cSVD burden. Perihematomal edema formation was measured using the edema extension distance (EED). We assessed the association between the cSVD burden and the EED using a multivariable linear regression model adjusting for age, (log-transformed) ICH volume, ICH location (lobar vs. non-lobar), and interval between symptom onset and MRI. Results: We included 85 patients (mean age 63.5 years, 75.3% male). Median interval between symptom onset and MRI imaging was 6 days (IQR 1-19). Median ICH volume was 17.0 mL (IQR 1.4-88.6), and mean EED was 0.54 cm (SD 0.17). We found no association between the total cSVD burden and EED (B = -0.003, 95% CI -0.003-0.03, p = 0.83), nor for any of the individual radiological cSVD markers. Conclusion: We found no association between the cSVD burden and PHE formation. This implies that mechanisms other than BBB dysfunction are involved in the pathophysiology of PHE.