ASA: Intensive antihypertensive treatment may control blood clot after stroke
Early intensive treatment for hypertension in patients with acute intracerebral hemorrhage (ICH) is well tolerated and appears to slow the growth of hematomas, according to a study presented at the annual American Stroke Association’s International Stroke Conference held this month in New Orleans.

Researchers in the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial (INTERACT) enrolled 404 patients from 44 hospitals in Australia, China and Korea in a pilot phase from November 2005 to April 2007.

Each patient was at least 18 years old, had an acute intracerebral hemorrhage (ICU) confirmed by CT and had elevated systolic blood pressure of 150 to 220 mm Hg. Each patient was able to begin treatment in a monitored environment within six hours of suffering an acute ICH.

Patients were assigned at random to receive either intensive anti-hypertensive treatment based on a stepped protocol of routinely available intravenous agents or a less intensive treatment based on American Heart Association guidelines. The target for the former group was to reduce systolic blood pressure to 140 mm Hg, while the target for the latter group was a reduction to 180 mm Hg.

After the first hour, systolic blood pressure was an average of 13.3 mm Hg lower in the intensive group than in the guidelines group. The average hematoma growth was 22.6 percent lower in the intensive group than in the guidelines group after adjusting for the initial hematoma volume and the time from onset of the ICH to CT scan. This equated to about a half of a teaspoon (2.5ml) of less blood in the brain from the treatment, according to the study.

At the same time, the frequency of “substantial” hematoma growth – defined by ongoing bleeding of more than one third of initial volume – was 36 percent lower in the intensive group than in the guidelines group.

After 90 days “there was no evidence that early intensive blood pressure-lowering increased the risks of serious adverse events or a poor outcome at 90 days,” the researchers reported.

“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 hemorrhage,” said lead author Craig Anderson, MD, PhD, a professor of stroke medicine and clinical neuroscience at the University of Sydney, Australia. “Furthermore, this treatment appears to limit bleeding in the brain in this type of stroke, which may improve chances of recovery for patients.”

He said this hypothesis will be tested in a much larger INTERACT study later this year.