Optimal achieved blood pressure in acute intracerebral hemorrhage: INTERACT2

OBJECTIVES: To investigate the effects of intensive blood pressure (BP) lowering according to baseline BP levels and optimal achieved BP levels in patients with acute intracerebral hemorrhage (ICH).

METHODS: INTERACT2 was an open, blinded endpoint, randomized controlled trial in 2,839 patients with ICH within 6 hours of onset and elevated systolic BP (SBP) (150-220 mm Hg) who were allocated to receive intensive (target SBP <140 mm Hg within 1 hour, with lower limit of 130 mm Hg for treatment cessation) or guideline-recommended (target SBP <180 mm Hg) BP-lowering treatment. Outcome was physical function across all 7 levels of the modified Rankin Scale at 90 days.

RESULTS: Analysis of the randomized comparisons showed that intensive BP lowering produced comparable benefits on physical function at 90 days in 5 subgroups defined by baseline SBP of <160, 160-169, 170-179, 180-189, and ≥190 mm Hg (p homogeneity = 0.790). Analyses of achieved BP showed linear increases in the risk of physical dysfunction for achieved SBP above 130 mm Hg for both hyperacute (1-24 hours) and acute (2-7 days) phases while modest increases were also observed for achieved SBP below 130 mm Hg.

CONCLUSIONS: Intensive BP lowering appears beneficial across a wide range of baseline SBP levels, and target SBP level of 130-139 mm Hg is likely to provide maximum benefit in acute ICH.

CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that the effect of intensive BP lowering on physical function is not influenced by baseline BP.