Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage

Summary

The purpose of the study is to determine whether lowering high blood pressure levels after the start of a stroke caused by bleeding in the brain (intracerebral haemorrhage) will reduce the chances of a person dying or surviving with a long term disability. The study will be undertaken in two phases: a vanguard phase in 400 patients, to plan for a main phase in 2000 patients.

Timeline

Start

2005-11

Primary completion

2007-09

Completion

2007-09

Publications

• Results Anderson CS, Huang Y, Wang JG, Arima H, Neal B, Peng B, Heeley E, Skulina C, Parsons MW, Kim JS, Tao QL, Li YC, Jiang JD, Tai LW, Zhang JL, Xu E, Cheng Y, Heritier S, Morgenstern LB, Chalmers J; INTERACT Investigators. Intensive blood pressure reduction in acute cerebral haemorrhage trial (INTERACT): a randomised pilot trial. Lancet Neurol. 2008 May;7(5):391-9. doi: 10.1016/S1474-4422(08)70069-3. Epub 2008 Apr 7.
• Wang X, Phan TG, Ren X, Ma HH, Li Q, Ouyang M, Delcourt C, Chen X, Wang J, Robinson TG, Arima H, Ma L, Hu X, You C, Liu L, Venturelli PM, Martins SC, Pontes-Neto OM, Chalmers JP, Song L, Qureshi AI, Anderson C. Systolic Blood Pressure Trajectory and Outcomes in Acute Intracerebral Hemorrhage: Pooled Analysis of the 4 INTERACT and ATACH-II Clinical Trials. Neurology. 2026 Apr 14;106(7):e214671. doi: 10.1212/WNL.0000000000214671. Epub 2026 Mar 19.
• Wang X, Ren X, Li Q, Ouyang M, Chen C, Delcourt C, Chen X, Wang J, Robinson T, Arima H, Ma L, Hu X, You C, Li G, Jie Y, Lin Y, Billot L, Munoz-Venturelli P, Martins S, Pontes-Neto OM, Liu L, Chalmers J, Carcel C, Song L, Anderson CS; INTERACT Investigators. Effects of blood pressure lowering in relation to time in acute intracerebral haemorrhage: a pooled analysis of the four INTERACT trials. Lancet Neurol. 2025 Jul;24(7):571-579. doi: 10.1016/S1474-4422(25)00160-7.
• Maegele M. Towards optimization in the use of hemostatic agents and blood products in the early treatment of patients with traumatic brain injury (TBI). Curr Opin Anaesthesiol. 2025 Apr 1;38(2):129-135. doi: 10.1097/ACO.0000000000001465. Epub 2025 Feb 14.
• You S, Zheng D, Yoshimura S, Ouyang M, Han Q, Wang X, Cao Y, Delcourt C, Song L, Arima H, Chen X, Liu CF, Lindley RI, Robinson T, Anderson CS, Chalmers J; INTERACT Investigators. Optimum Baseline Clinical Severity Scale Cut Points for Prognosticating Intracerebral Hemorrhage: INTERACT Studies. Stroke. 2024 Jan;55(1):139-145. doi: 10.1161/STROKEAHA.123.044538. Epub 2023 Nov 29.
• Sandset EC, Wang X, Carcel C, Sato S, Delcourt C, Arima H, Stapf C, Robinson T, Lavados P, Chalmers J, Woodward M, Anderson CS. Sex differences in treatment, radiological features and outcome after intracerebral haemorrhage: Pooled analysis of Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage trials 1 and 2. Eur Stroke J. 2020 Dec;5(4):345-350. doi: 10.1177/2396987320957513. Epub 2020 Sep 20.
• Wang X, Moullaali TJ, Li Q, Berge E, Robinson TG, Lindley R, Zheng D, Delcourt C, Arima H, Song L, Chen X, Yang J, Chalmers J, Anderson CS, Sandset EC. Utility-Weighted Modified Rankin Scale Scores for the Assessment of Stroke Outcome: Pooled Analysis of 20 000+ Patients. Stroke. 2020 Aug;51(8):2411-2417. doi: 10.1161/STROKEAHA.119.028523. Epub 2020 Jul 9.
• Wang X, Sandset EC, Moullaali TJ, Chen G, Song L, Carcel C, Delcourt C, Woodward M, Robinson T, Chalmers J, Arima H, Anderson CS; INTERACT2 Investigators. Determinants of the high admission blood pressure in mild-to-moderate acute intracerebral hemorrhage. J Hypertens. 2019 Jul;37(7):1463-1466. doi: 10.1097/HJH.0000000000002056.
• Chen R, Wang X, Anderson CS, Robinson T, Lavados PM, Lindley RI, Chalmers J, Delcourt C. Infratentorial Intracerebral Hemorrhage. Stroke. 2019 May;50(5):1257-1259. doi: 10.1161/STROKEAHA.118.023766.
• Delcourt C, Zheng D, Chen X, Hackett M, Arima H, Hata J, Heeley E, Al-Shahi Salman R, Woodward M, Huang Y, Robinson T, Lavados PM, Lindley RI, Stapf C, Davies L, Chalmers J, Anderson CS, Sato S; INTERACT Investigators. Associations with health-related quality of life after intracerebral haemorrhage: pooled analysis of INTERACT studies. J Neurol Neurosurg Psychiatry. 2017 Jan;88(1):70-75. doi: 10.1136/jnnp-2016-314414. Epub 2016 Oct 21.
• Song L, Sandset EC, Arima H, Heeley E, Delcourt C, Chen G, Yang J, Wu G, Wang X, Lavados PM, Huang Y, Stapf C, Wang J, Robinson TG, Chalmers J, Lindley RI, Anderson CS; INTERACT2 Investigators. 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.
• Qiu M, Sato S, Zheng D, Wang X, Carcel C, Hirakawa Y, Sandset EC, Delcourt C, Arima H, Wang J, Chalmers J, Anderson CS; INTERACT Investigators*. Admission Heart Rate Predicts Poor Outcomes in Acute Intracerebral Hemorrhage: The Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial Studies. Stroke. 2016 Jun;47(6):1479-85. doi: 10.1161/STROKEAHA.115.012382. Epub 2016 May 10.
• Moullaali TJ, Sato S, Wang X, Rabinstein AA, Arima H, Carcel C, Chen G, Robinson T, Heeley E, Chan E, Delcourt C, Stapf C, Cordonnier C, Lindley RI, Chalmers J, Anderson CS; INTERACT Investigators. Prognostic significance of delayed intraventricular haemorrhage in the INTERACT studies. J Neurol Neurosurg Psychiatry. 2017 Jan;88(1):19-24. doi: 10.1136/jnnp-2015-311562. Epub 2016 Jan 8.
• Wang X, Arima H, Al-Shahi Salman R, Woodward M, Heeley E, Stapf C, Lavados PM, Robinson T, Huang Y, Wang J, Delcourt C, Anderson CS. Rapid Blood Pressure Lowering According to Recovery at Different Time Intervals after Acute Intracerebral Hemorrhage: Pooled Analysis of the INTERACT Studies. Cerebrovasc Dis. 2015;39(3-4):242-8. doi: 10.1159/000381107. Epub 2015 Mar 25.
• Yang J, Arima H, Wu G, Heeley E, Delcourt C, Zhou J, Chen G, Wang X, Zhang S, Yu S, Chalmers J, Anderson CS; INTERACT Investigators. Prognostic significance of perihematomal edema in acute intracerebral hemorrhage: pooled analysis from the intensive blood pressure reduction in acute cerebral hemorrhage trial studies. Stroke. 2015 Apr;46(4):1009-13. doi: 10.1161/STROKEAHA.114.007154. Epub 2015 Feb 24.
• Priglinger M, Arima H, Anderson C, Krause M; INTERACT Investigators. No relationship of lipid-lowering agents to hematoma growth: pooled analysis of the intensive blood pressure reduction in acute cerebral hemorrhage trials studies. Stroke. 2015 Mar;46(3):857-9. doi: 10.1161/STROKEAHA.114.007664. Epub 2015 Feb 5.
• Sato S, Heeley E, Arima H, Delcourt C, Hirakawa Y, Pamidimukkala V, Li Z, Tao Q, Xu Y, Hennerici MG, Robinson T, Tzourio C, Lindley RI, Chalmers J, Anderson CS; INTERACT Investigators; Anderson CS, Huang Y, Wang JG, Arima H, Neal B, Peng B, Heeley E, Skulina C, Parsons MW, Kim JS, Tao QL, Li YC, Jiang JD, Tai LW, Zhang LJ, Xu E, Cheng Y, Heritier S, Morgenstern LB, Chalmers J. Higher mortality in patients with right hemispheric intracerebral haemorrhage: INTERACT1 and 2. J Neurol Neurosurg Psychiatry. 2015 Dec;86(12):1319-23. doi: 10.1136/jnnp-2014-309870. Epub 2015 Jan 14.
• Wang X, Arima H, Al-Shahi Salman R, Woodward M, Heeley E, Stapf C, Lavados PM, Robinson T, Huang Y, Wang J, Delcourt C, Anderson CS; INTERACT Investigators. Clinical prediction algorithm (BRAIN) to determine risk of hematoma growth in acute intracerebral hemorrhage. Stroke. 2015 Feb;46(2):376-81. doi: 10.1161/STROKEAHA.114.006910. Epub 2014 Dec 11.
• Delcourt C, Huang Y, Arima H, Chalmers J, Davis SM, Heeley EL, Wang J, Parsons MW, Liu G, Anderson CS; INTERACT1 Investigators. Hematoma growth and outcomes in intracerebral hemorrhage: the INTERACT1 study. Neurology. 2012 Jul 24;79(4):314-9. doi: 10.1212/WNL.0b013e318260cbba. Epub 2012 Jun 27.
• Arima H, Huang Y, Wang JG, Heeley E, Delcourt C, Parsons M, Li Q, Neal B, Chalmers J, Anderson C; INTERACT1 Investigators. Earlier blood pressure-lowering and greater attenuation of hematoma growth in acute intracerebral hemorrhage: INTERACT pilot phase. Stroke. 2012 Aug;43(8):2236-8. doi: 10.1161/STROKEAHA.112.651422. Epub 2012 Jun 7.
• Arima H, Anderson CS, Wang JG, Huang Y, Heeley E, Neal B, Woodward M, Skulina C, Parsons MW, Peng B, Tao QL, Li YC, Jiang JD, Tai LW, Zhang JL, Xu E, Cheng Y, Morgenstern LB, Chalmers J; Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage Trial Investigators. Lower treatment blood pressure is associated with greatest reduction in hematoma growth after acute intracerebral hemorrhage. Hypertension. 2010 Nov;56(5):852-8. doi: 10.1161/HYPERTENSIONAHA.110.154328. Epub 2010 Sep 7.

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