Early Achievement of Blood Pressure Lowering and Hematoma Growth in Acute Intracerebral Hemorrhage: Stroke Acute Management with Urgent Risk-Factor Assessment and Improvement-Intracerebral Hemorrhage Study

BACKGROUND: Previous studies have revealed that hematoma growth mainly occurs during the first 6 h after the onset of spontaneous intracerebral hemorrhage (ICH). Early lowering of blood pressure (BP) may be beneficial for preventing hematoma growth. However, relationships between timing of BP lowering and hematoma growth in ICH remain unclear. We investigated associations between timing of BP lowering and hematoma growth for ICH. METHODS: The Stroke Acute Management with Urgent Risk-factor Assessment and Improvement (SAMURAI)-ICH Study was a multicenter, prospective, observational study investigating the safety and feasibility of early (within 3 h from onset) reduction of systolic BP (SBP) to < 160 mm Hg with intravenous nicardipine for acute hypertension in cases of spontaneous ICH. The present study was a post hoc analysis of the SAMURAI-ICH study. We examined relationships between time from onset, imaging, and initiation of treatment to target SBP achievement and hematoma growth (absolute growth ≥6 mL) in ICH patients. Target SBP achievement was defined as the time at which SBP first became < 160 mm Hg. RESULTS: Among 211 patients, hematoma growth was seen in 31 patients (14.7%). The time from imaging to target SBP and time from treatment to target SBP were significantly shorter in patients without hematoma growth than in those with (p = 0.043 and p = 0.032 respectively), whereas no significant difference was seen in time from onset to SBP < 160 mm Hg between groups (p = 0.177). Patients in the lower quartiles of time from imaging to target SBP and time from treatment to target SBP showed lower incidences of hematoma growth (p trend = 0.023 and 0.037 respectively). The lowest quartile of time from imaging to target SBP (< 38 min) was negatively associated with hematoma growth on multivariable logistic regression (OR 0.182; 95% CI 0.038-0.867; p = 0.032). CONCLUSIONS: Early achievement of target SBP < 160 mm Hg is associated with a lower risk of hematoma growth in ICH.