Regional Differences in the Response to Acute Blood Pressure Lowering After Cerebral Hemorrhage

Objective:To compare the impact of intensive blood pressure (BP) lowering right after intracerebral hemorrhage (ICH) on clinical and hematoma outcomes among patients from different geographic locations, we performed a prespecified sub-analysis of the randomized, multi-national, two-group, open-label trial to determine the efficacy of rapidly lowering BP in hyperacute ICH (ATACH-2), involving 537 patients from East Asia and 463 recruited outside of Asia.Methods:Eligible patients were randomly assigned to a systolic BP (SBP) target of 110-139 mmHg (intensive treatment) or 140-179 mmHg (standard treatment). Pre-defined outcomes were: poor functional outcome (modified Rankin Scale score of 4-6 at 90 days), death within 90 days, hematoma expansion at 24 hours; and cardio-renal adverse events within 7 days.Results:Poor functional outcomes (32.0% versus 45.9%), death (1.9% versus 13.3%), and cardio-renal adverse events (3.9% versus 11.2%) occurred significantly less in patients from Asia than those outside of Asia. The treatment-by-cohort interaction was not significant for any outcomes. Only patients from Asia showed a lower incidence of hematoma expansion with intensive treatment (adjusted RR 0.56, 95% CI 0.38-0.83). Both Asian (3.53, 1.28-9.64) and non-Asian cohorts (1.71, 1.00-2.93) showed a higher incidence of cardio-renal adverse events with intensive treatment.Conclusions:Poor functional outcomes and death 90 days after ICH were less common in patients from East Asia than those outside of Asia. Hematoma expansion, a potential predictor for poor clinical outcome, was attenuated by intensive BP lowering only in the Asian cohort.Clinicaltrials.gov identifierNCT01176565.Classification of evidence:This study provides Class II evidence that, for patients from East Asia with intracerebral hemorrhage, intensive blood pressure lowering significantly reduces the risk of hematoma expansion.