Lowering blood pressure of individuals who have just had an intracranial haemorrhage to below that specified by existing guidelines seems to reduce haematoma growth, according to an Article to be published in the May issue of The Lancet Neurology.
Intracranial haemorrhage often causes the person's blood pressure to rise rapidly, which may contribute to further haemorrhage and the growth of the haematoma – an area of internal bleeding – that could lead to a deterioration in their condition and ultimately to an increased risk of early death or residual disability (because of increased pressure on vital structures in the brain). Although strategies are recommended to lower very high blood pressure as soon as possible after such a haemorrhage, there is little evidence about when to start the treatment or how much to lower blood pressure, so there is wide variation in the management of high blood pressure in this clinical situation around the world.
To try to clarify this issue, Dr Craig Anderson, at The George Institute for International Health, Sydney, Australia, and colleagues undertook a randomised pilot trial in hospitals in Australia, China and South Korea between November 2005 and August 2007. The study compared an intensive blood-pressure-lowering strategy (target systolic blood pressure 140 mm Hg) in 203 individuals with the recommended best practice standard strategy (target systolic blood pressure 180 mm Hg) in 201 people with spontaneous intracerebral haemorrhage.
For entry into the trial, patients had the diagnosis confirmed by having had a brain scan by CT (computerised tomography). The scan was repeated 24 hours after the treatment started, to check for haematoma growth. In the intensive treatment group, haematoma growth was 13.7% compared with 36.3% in the non-intensive group—a statistically significant difference. Crucially, the groups did not differ in the numbers of adverse side-effects from treatment nor in any of the secondary clinical outcomes that measured the number of deaths and the degrees of disability, physical and mental functioning and quality of life in survivors at 90 days.
The authors conclude: "Because intravenous treatment to lower blood pressure is relatively straightforward, is not hazardous, and is of low cost, if applied widely these effects could translate into major absolute benefits."
The researchers plan to proceed with the next phase of the trial, which is to assess the effect of the intensive treatment on the key clinical outcome of death and dependency in 2800 patients who have had an intracranial haemorrhage from sites around the world.
In an accompanying Comment, Dr Mustapha Ezzeddine (University of Minnesota, Minneapolis, USA) says: "The INTERACT trial represents the best evidence to date of the safety of such an intervention". He adds that although many questions—such as whether these results are generalisable to other stroke patients and how long blood pressure needs to be controlled for—remain unanswered, the follow-up studies of INTERACT, and a related trial ATACH2, "will be able to answer some of these questions, but more importantly, detect any impact on outcomes".
Dr Craig Anderson, The George Institute for International Health, University of Sydney, PO Box M201, Missenden Road, NSW 2050, Australia canderson@george.org.au T) +61 2 9993 4521
Dr Mustapha Ezzeddine, Department of Neurology, University of Minnesota, 420 Delaware St, Minneapolis, MN 55403, USA. ezzeddin@umn.edu T) +1-404-661-8818
Journal
The Lancet Neurology