INTERACT trial to look at effects of early intensive blood pressure lowering on death and disability in stroke patients

Nov 1 2005

A large clinical trial called INTERACT, launched in China this month, will determine the effects of early intensive blood pressure lowering on death and disability in stroke patients. The INTERACT trial aims to provide reliable evidence about what is the optimal approach to managing blood pressure after intra-cerebral haemorrhage.

Intra-cerebral haemorrhage is one of the most serious forms of stroke, affecting 2-3 million people worldwide each year. Most of these live in China and surrounding Asian countries, and about one third will die a few days after onset. Of those that survive, the majority will face major long-term disabilities.

The George Institute's Professor Craig Anderson, who is the Principal Investigator in the trial, explained that "Chinese people appear to be at particularly high risk of intra-cerebral haemorrhage. This is partly due to the high prevalence of high blood pressure in the population and possibly to genetic factors.

"Despite the magnitude of the burden imposed by this disease, and the high cost to health services, there is no widely available treatment for the condition. However, early rapid blood pressure lowering shows considerable promise as a widely applicable, cost-effective therapy that can be readily incorporated into clinical practice," noted Prof Anderson. Although surgery is sometimes used in patients with severe intra-cerebral haemorrhage to relieve pressure on the brain, a recently published large-scale clinical trial has cast doubt over which patients most benefit from surgery.

In another approach to treatment, early administration of a laboratory-developed clotting factor, called activated recombinant human Factor VII (NovoSeven), has been shown to limit expansion of bleeding in the brain and improve recovery in an international clinical trial that was published in the New England Journal of Medicine early this year. However, future use of this agent in clinical practice will be limited by the narrow time window for use after stroke onset, avoidance of its use in patients at high risk of clotting, and it's expense.

"Blood pressure is commonly elevated, sometimes to very high levels, after the onset of intra-cerebral haemorrhage and there is some evidence to suggest that lowering blood pressure levels improves outcomes" according to Professor Huang Yining, Co-Principal Investigator for INTERACT in China, and Professor of Neurology, Peking University First Hospital.

"The study will establish the safety and effects of a management policy of early intensive blood pressure lowering on death and disability, compared to current less intensive, guideline-based management of blood pressure in this clinical setting", said Professor Huang.