Degree and Timing of Intensive Blood Pressure Lowering on Hematoma Growth in Intracerebral Hemorrhage

Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial-2 Results

Carcel C, Wang X, Sato S, et al.

Stroke. 2016;47: published online ahead of print

Background

Intensive BP-lowering after an acute spontaneous intracerebral haemorrhage (ICH) is thought be beneficial due to the attenuation of the haematoma growth. However, this was not confirmed in the INTERACT (Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial) study [1,2].

INTERACT2 was a multicentre, randomised trial, in which 2839 ICH patients with elevated systolic (SBP) were assigned to intensive (target SBP <140 mm Hg within 1 hour) or guideline-recommended (target SBP <180 mm Hg) BP-lowering, within 6 hours of ICH onset [2].

In the present analysis, the degree and timing of BP-lowering in relation to hematoma growth was evaluated in 964 INTERACT2 study participants, who had repeat cranial computed tomography at 24 hours.

Main results

Greater SBP reduction (1-24 hours) was associated with reduced hematoma growth (Ptrend<0.001):

• ·13.3 mL growth for <10 mm Hg SBP reduction; 95% CI: 9.0–17.5 mL
• ·5.0 mL growth for 10–20 mm Hg SBP reduction; 95% CI: 1.6–8.4 mL
• ·3.0 mL growth for ≥20 mm Hg SBP reduction; 95% CI: 0.5–5.4 mL

In the intensive treatment group (n=491):

• ·the SBP target was achieved in 242 individuals (49%) within 1 hour, 125 individuals (25%) within 1-6 hours
• ·the SBP target was not achieved in 124 individuals (25%) within <6 hours
• ·the least hematoma growth (average) was observed in those achieving target SBP early (Ptrend=0.029): ≤1 hour: 2.6 mL; 95% CI: 0.1–5.2, 1-6 hours: 4.7 mL; 95% CI: 1.8–7.5, >6 hours: 5.4 mL; 95% CI: 2.4–8.3

Haematoma growth was smallest in those achieving SBP target on multiple occasions (Ptrend=0.018):

• ·for 0-2 times to target SBP: 5.2 mL; 95% CI: 2.7–7.8
• ·for 3-4 times to target SBP: 3.1 mL; 95% CI: 0.3–6.0
• ·for 5-8 times to target SBP: 0.4 mL; 95% CI: –1.1 to 5.1

Conclusion

In 964 ICH patients with elevated BP, the greatest and fastest SBP-lowering was associated with less haematoma growth. The relation of haematoma growth with fall in SBP was irrespective of treatment regime (intensive or standard-guideline). These results suggest that there is a beneficial effect of early and controlled BP-lowering treatment through the attenuation of haematoma growth, and support recent guideline recommendations for more intensive BP management in ICH.

Find this article online at Stroke

References

1. Arima H, Huang Y, Wang JG, et al; INTERACT1 Investigators. Earlier blood pressure-lowering and greater attenuation of hematoma growth in acute intracerebral hemorrhage: INTERACT pilot phase. Stroke. 2012;43:2236–2238.

2. Anderson CS, Chalmers J, Stapf C. Blood-pressure lowering in acute intracerebral hemorrhage. N Engl J Med. 2013;369:1274–1275.