Study identifies a safer treatment of acute stroke

The safety of intravenous rtPA (or alteplase) has been investigated by researchers, who have shown a modified dosage can reduce serious bleeding in the brain and improve survival rates.

It is hoped the findings from the trial of more than 3,000 patients in 100 hospitals worldwide could change the way the most common form of stroke is treated globally.

rtPA is given to people suffering acute ischaemic stroke and works by breaking up clots blocking the flow of blood to the brain. However, it can cause serious bleeding in the brain in around five percent of cases, with many of these proving fatal.

Concerns over the risks of bleeding on the brain associated with rtPA prompted the study by teams at the George Institute for Global Health, and the University of Leicester‘s Department of Cardiovascular Sciences.

The study found that compared to standard dose (0.9mg/kg body weight), a lower dose (0.6mg/kg) of rtPA reduced rates of serious bleeding in the brain, known as intracerebral haemorrhage (ICH), by two thirds. After 90 days, 8.5 percent of patients had died after receiving low dose rtPA, compared to 10.3 percent who received the standard dose.

Commenting on the results, National Coordinator of the study in the UK, Professor Tom Robinson of Leicester said: “The results provide important information when discussing clot-busting treatment with patients and their families.

“Most patients who have a major stroke want to know they will survive but without being seriously dependent on their family. We have shown this to be the case with the lower dose of the drug.”

Professor Craig Anderson added: “At the moment you could have a stroke but end up dying from a bleed in the brain. It’s largely unpredictable as to who will respond and who is at risk with rtPA.

“What we have shown is that if we reduce the dose level, we maintain most of the clot busting benefits of the higher dose but with significantly less major bleeds and improved survival rates. On a global scale, this approach could save the lives of many tens of thousands of people.”

Survival benefit offset by rise in residual disability

The study also found that the survival benefit was offset by a slight rise in the amount of people suffering residual disability. For every 1000 patients treated with low dose rtPA, compared to the standard dose, 41 more people had physical disabilities, such as needing help dressing or walking, but 19 fewer people died.

Professor Anderson commented: “There is a trade off with the lower dose in regards to recovery of functioning, but being alive is surely preferable to most patients than suffering an early death.”