"Sharp Blood Pressure Reduction Helps Shrink Haematomas Safely: Presented at ISC"
By Carole Bullock
NEW ORLEANS -- February 25, 2008 -- Reduction of high blood pressure (BP) levels after the start of a haemorrhagic stroke arrested the growth of haematomas in a 90-day, multicentre, follow-up study presented here at the International Stroke Conference (ISC) 2008.
Principal investigator, Craig Anderson, MD, PhD, Director, Neurological and Mental Health Division, Professor, Stroke Medicine and Clinical Neuroscience, Royal Prince Alfred Hospital, University of Sydney, Sydney, Australia, reported results of the pilot phase of the study on February 22.
Dr. Anderson and colleagues found the frequency of "substantial" haematoma growth -- defined by ongoing bleeding of more than one-third of initial volume -- was 36% lower among patients in the group who received intensive BP-lowering therapy compared with the control group (95% confidence interval [CI] 0-59%; [P = .05) .
The study was published simultaneously in the February 22 issue of The Lancet Neurology.
"Our goal was to resolve an area of medical uncertainty -- does early lowering of elevated blood pressure improve outcome in patients with acute intracerebral haemorrhage?" Dr. Anderson said. To answer this question, the researchers launched a phase 2 proof-of-concept study to determine the feasibility and neurological safety of rapid blood pressure lowering.
Initiated in 2005, the multicentre Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage Trial (INTERACT) enrolled 404 patients with BP levels between 150 and 220 mm Hg with acute spontaneous intracerebral haemorrhage confirmed by computed tomography scan.
Patients were randomised to an intensive BP-lowering regimen based on a stepped protocol of routinely available IV therapies to a target level of 140 mm Hg (intensive treatment) or to BP management following American Heart Association guidelines to a target dose of less than 180 mm Hg control). Patients were all treated within 6 hours of intracranial haemorrhage.
The cohort had an average age of 62 years; almost two-thirds began the protocol within 3 hours. Baseline characteristic were similar, with BP levels averaging 180/100 mm Hg. About two-thirds had hypertension and 84% had a deep location of haematoma.
Exclusion criteria were contraindications to an intensive BP-lowering regimen, known definite indications for an intensive BP-lowering regimen, ICH secondary to a structural abnormality in the brain, a previous stroke within the previous 30 days, or certain concomitant medical illness.
Systolic blood pressure within an hour of enrolment was an average of 13.3 mm Hg lower in the intensive treatment group than in the control group (P < .0001).
Average haematoma growth was 22.6% lower in the intensive treatment group compared with the control group, after adjusting for the initial haematoma volume and time from onset of the intracerebral haemorrhage to CT scan (36.3 mL vs 13.7 mL; 95% CI 0.6-44.5%; adjusted P = .06).
At 90 days, 40 and 48 patients, respectively, had a "death or dependency" status (P = .80). There were no other major significant differences in the Modified Rankin Scale or National Institutes of Health Stroke Scale scores.
The researchers observed no evidence of serious adverse events or poor outcome at 90 days.
The most common adverse event was neurological worsening, which occurred in 15 patients in each group. There was 1 recurrent stroke in the intensive treatment group and 2 in the control group.
"The results of the INTERACT study show that drug treatment to lower elevated blood pressure can be given quickly and safely to patients with intracranial haemorrhage. Furthermore, this treatment appears to limit bleeding in the brain in this type of stroke, which may improve chances of recovery for patients," said Dr. Anderson.
The investigators noted that it will be up to a larger trial (INTERACT 2) to tackle the question of whether haematoma shrinkage will be clinically meaningful. However, Dr. Anderson said, "antihypertensive drugs are inexpensive…so widespread adoption could translate into large numbers of saved lives."
The study is funded by the National Health and Medical Research Council of Australia.
[Presentation title: The Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial (INTERACT): Results of the Vanguard Phase. LB3]
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