Early blood pressure lowering in patients with intracerebral haemorrhage and prior use of antithrombotic agents: pooled analysis of the INTERACT studies

J Neurol Neurosurg Psychiatry. 2016 Dec;87(12):1330-1335. doi: 10.1136/jnnp-2016-313246. Epub 2016 May 13.


Objective: Antithrombotic agents increase risks of intracerebral haemorrhage (ICH) and associated adverse outcomes. We determined differential effects of early blood pressure (BP) lowering in patients with/without antithrombotic-associated ICH in the Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage Trials (INTERACT1 and 2).

Design: Post hoc pooled analyses of the INTERACT studies-international, multicentre, prospective, open, blinded end point trials of patients with ICH (<6 h) and elevated systolic BP (SBP 150-180 mm Hg) randomly assigned to intensive (target SBP <140 mm Hg) or guideline-based (SBP <180 mm Hg) BP management. Associations of antithrombotic use and (1) death or dependency (modified Rankin scale scores 3-6) were analysed using logistic regression, and (2) of increased haematoma+intraventricular haemorrhage volume (IVH) with/without intraventricular haemorrhage (IVH) over 24 h were estimated in analyses of covariance.

Results: In all, 3184 patients were included in these analyses. Antithrombotic-associated ICH (364 patients, 11%) was not associated with a significantly increased risk of death or dependency (OR 1.38, 95% CI 0.93 to 2.04). There was no heterogeneity in the BP-lowering treatment effect on death or dependency. Among 1309 patients who underwent follow-up CT after 24 h, absolute increase in haematoma±IVH volume was larger (5.2/5.0 mL) in those with compared to those without prior antithrombotics (2.2/0.9 mL; p=0.022/0.031). Intensive BP lowering reduced haematoma±IVH growth by 4.7/7.1 mL in patients on antithrombotics versus 1.3/1.4 mL in those without, although these differences did not reach statistical significance (p homogeneity=0.104/0.059).

Conclusions: In patients with ICH, prior antithrombotic therapy is associated with greater haematoma growth, which may be reduced by early intensive BP-lowering treatment.

Trial registration number: NCT00226096, NCT00716079.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Aged, 80 and over
  • Antihypertensive Agents / therapeutic use*
  • Blood Pressure / drug effects
  • Cerebral Hemorrhage / chemically induced*
  • Cerebral Hemorrhage / mortality
  • Disability Evaluation
  • Double-Blind Method
  • Early Medical Intervention*
  • Female
  • Fibrinolytic Agents / adverse effects*
  • Humans
  • Hypertension / complications
  • Hypertension / drug therapy*
  • Hypertension / mortality
  • Male
  • Middle Aged
  • Preoperative Care*
  • Prospective Studies
  • Risk
  • Statistics as Topic


  • Antihypertensive Agents
  • Fibrinolytic Agents

Associated data

  • ClinicalTrials.gov/NCT00226096
  • ClinicalTrials.gov/NCT00716079