Magnitude of blood pressure reduction and clinical outcomes in acute intracerebral hemorrhage: Intensive blood pressure reduction in acute cerebral hemorrhage trial study

Evidence supports early intensive blood pressure (BP) lowering in acute intracerebral hemorrhage, but uncertainty persists over whether potential benefits and harms vary according to the magnitude of BP reduction. We aimed to determine whether larger systolic BP (SBP) reductions were associated with better outcomes in participants of the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial (INTERACT2). INTERACT2 was an international, open, blinded end point, randomized controlled trial of patients with spontaneous intracerebral hemorrhage (<6 hours) and elevated SBP (150-220 mm Hg) assigned to intensive (target SBP <140 mm Hg) or guideline-recommended (SBP <180 mm Hg) treatment. Associations of BP reduction (baseline minus average of achieved SBP) during 3 time periods post randomization (15-60 minutes, 1-24 hours, and 2-7 days) on poor outcome (death or major disability) at 90 days were analyzed in multivariable logistic regression models with odds ratios and 95% confidence intervals. Larger SBP reductions within the first hour after randomization were associated with lower risks of poor outcome: compared with minimal reduction (<10 mm Hg), odds ratios were 0.80 (95% confidence interval, 0.63-1.02) for moderate (10-20 mm Hg) and 0.65 (0.52-0.82) for large (≥20 mm Hg) reductions (P trend <0.01). Similar associations were also observed for SBP reductions during 1 to 24 hours (P<0.01) and 2 to 7 days (P 0.02). No heterogeneity in associations for patients above or below baseline SBP 180 mm Hg was reported (P>0.30). Optimal recovery from intracerebral hemorrhage was observed in hypertensive patients who achieved the greatest SBP reductions (≥20 mm Hg) in the first hour and maintained for 7 days.