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 subanalysis of a randomized, multinational, 2-group, open-label trial to determine the efficacy of rapidly lowering BP in hyperacute ICH (Antihypertensive Treatment of Acute Cerebral Hemorrhage [ATACH]-2), involving 537 patients from East Asia and 463 recruited outside of Asia. METHODS: Eligible patients were randomly assigned to a systolic BP target of 110 to 139 mm Hg (intensive treatment) or 140 to 179 mm Hg (standard treatment). Predefined outcomes were poor functional outcome (modified Rankin Scale score 4–6 at 90 days), death within 90 days, hematoma expansion at 24 hours, and cardiorenal adverse events within 7 days. RESULTS: Poor functional outcomes (32.0% vs 45.9%), death (1.9% vs 13.3%), and cardiorenal adverse events (3.9% vs 11.2%) occurred significantly less frequently 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 relative risk [RR] 0.56, 95% confidence interval [CI] 0.38–0.83). Both Asian (RR 3.53, 95% CI 1.28–9.64) and non-Asian (RR 1.71, 95% CI 1.00–2.93) cohorts showed a higher incidence of cardiorenal 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 IDENTIFIER: NCT01176565. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, for patients from East Asia with ICH, intensive blood pressure lowering significantly reduces the risk of hematoma expansion.