Effects of blood pressure and tranexamic acid in spontaneous intracerebral haemorrhage: a secondary analysis of a large randomised controlled trial

Abstract

Background: Tranexamic acid reduced haematoma expansion and early death, but did not improve functional outcome in the tranexamic acid for hyperacute spontaneous intracerebral haemorrhage-2 (TICH-2) trial. In a predefined subgroup, there was a statistically significant interaction between prerandomisation baseline systolic blood pressure (SBP) and the effect of tranexamic acid on functional outcome (p=0.019).

Methods: TICH-2 was an international prospective double-blind placebo-controlled randomised trial evaluating intravenous tranexamic acid in patients with acute spontaneous intracerebral haemorrhage (ICH). Prerandomisation baseline SBP was split into predefined ≤170 and >170 mm Hg groups. The primary outcome at day 90 was the modified Rankin Scale (mRS), a measure of dependency, analysed using ordinal logistic regression. Haematoma expansion was defined as an increase in haematoma volume of >33% or >6 mL from baseline to 24 hours. Data are OR or common OR (cOR) with 95% CIs, with significance at p<0.05.

Results: Of 2325 participants in TICH-2, 1152 had baseline SBP≤170 mm Hg and were older, had larger lobar haematomas and were randomised later than 1173 with baseline SBP>170 mm Hg. Tranexamic acid was associated with a favourable shift in mRS at day 90 in those with baseline SBP≤170 mm Hg (cOR 0.73, 95% CI 0.59 to 0.91, p=0.005), but not in those with baseline SBP>170 mm Hg (cOR 1.05, 95% CI 0.85 to 1.30, p=0.63). In those with baseline SBP≤170 mm Hg, tranexamic acid reduced haematoma expansion (OR 0.62, 95% CI 0.47 to 0.82, p=0.001), but not in those with baseline SBP>170 mm Hg (OR 1.02, 95% CI 0.77 to 1.35, p=0.90).

Conclusions: Tranexamic acid was associated with improved clinical and radiological outcomes in ICH patients with baseline SBP≤170 mm Hg. Further research is needed to establish whether certain subgroups may benefit from tranexamic acid in acute ICH.

Trial registration number: ISRCTN93732214.

Keywords: STROKE.

Figure 1

Effect of TXA versus placebo on the primary outcome (mRS) by prerandomisation baseline systolic blood pressure. (A) Distribution of mRS at day 90 by TXA versus placebo in those with baseline systolic BP≤170 mm Hg: cOR 0.73, 95% CI 0.59 to 0.91, p=0.005. Ordinal logistic regression with adjustment for baseline prognostic factors. (B) Distribution of mRS at day 90 by TXA versus placebo in those with baseline systolic BP>170 mm Hg: cOR 1.05, 95% CI 0.85 to 1.30, p=0.63. Ordinal logistic regression with adjustment for baseline prognostic factors. BP, blood pressure; cOR, common OR; mRS, modified Rankin Scale; TXA, tranexamic acid.