Information for people participating in IST3 and their families

 

The Third International Stroke Trial (IST-3) is a large clinical study designed to assess whether ‘clot-busting’ treatment for the commonest cause of stroke is beneficial for patients.

 

What is a stroke?

A stroke occurs when the blood supply to the brain is interrupted, most commonly by a blood clot (thrombosis), and less commonly by a burst blood vessel (haemorrhage). The common symptoms of stroke are best summarised by the FAST campaign poster:

For more details about what to do if you think someone may be having a stroke please see:

 

http://www.stroke.org.uk/campaigns/raising_awareness/act_fast.html

Unfortunately, a stroke is a serious and sometimes fatal condition. After a stroke, about a third of people will die due to their stroke within a year, and a third will be left with significant problems such as physical or psychological disability. As a result of these harsh facts, stroke is the third commonest cause of death in most countries (after heart attacks and cancer) and is the commonest adult cause of serious physical disability. For more information about the causes of stroke please see:

 

http://www.stroke.org.uk/index.html

http://www.chss.org.uk/

 

Types of Stroke

Strokes due to blood clots are called ‘Ischaemic Strokes’

Strokes due to burst blood vessels are called ‘Primary Intracerebral Haemorrhages’ or haemorrhagic strokes.

 

However, often you cannot tell whether the stroke has been ischaemic or haemorrhagic until a brain scan is done. We have two commonly used brain scanners available: CT scanners (performing a ‘CAT scan’), which use X-ray technology; and MRI scanners, which use an alternative technology.  When a stroke is diagnosed, it is really important to get a brain scan done as soon as possible so that doctors can identify whether the stroke is ischaemic or haemorrhagic.

 

For more information about CT scanners please see:

http://www.cks.nhs.uk/patient_information_leaflet/ct_scan

For more information about MRI scanners please see

 http://www.sbirc.ed.ac.uk/subjects.html

 

 

Current Stroke Treatments

If a person’s stroke is confirmed to be ischaemic, we have two medical treatments to offer. Immediate aspirin has been shown to improve outcome, although the effects are small. Immediate ‘clot-busting’ treatment is much more effective, but currently is not available to everyone as it is a treatment that requires special facilities, and not every hospital is yet able to offer this routinely.

 

The most widely used ‘clot-busting’ treatment is called alteplase, and is also called rt-PA since its alternative name is ‘recombinant tissue plasminogen activator’ – rt-PA for short. The rt-PA is a medicine that has to be injected into the blood stream for it to work, and it helps to dissolve blood clots that have caused the stroke. In Europe, rt-PA is approved for only a highly selected group of patients:

 

 

Detailed information about the clotbusting drug rt-PA can be found here

http://www.medicines.org.uk/emc/document.aspx?documentId=308#INDICATIONS

 

We hope that IST-3 will provide important new information to greatly increase the number of people who can be treated with rt-PA.

 

Risks of rt-PA Treatment

Unfortunately, rt-PA can also cause side effects, the most serious being bleeding, especially in the brain, with a risk as serious as that of a major surgical operation. As in major surgery, these risks can be worthwhile for some people. 

 

Why the need for a study?

IST-3 has been designed to find out if rt-PA could work for a much larger group of patients with sudden stroke than those who are treated at present. In particular, it would be really important to know if people treated later (up to 6 hours after the onset of stroke symptoms) or who are older (especially those over 80 years of age) would benefit. If we could prove that treatment was still safe and effective for older people, and those treated later, many more people could be saved from serious disability.

 

The Study

IST-3 is a randomised controlled study – a standard research design in medicine, where half the group receives the treatment and the other does not, so that the two groups can be compared to see if the treatment is effective. In IST-3, half the people will get the rt-PA injection and half will avoid the injection. People in the study are then followed up to see if those who got the rt-PA were more independent six months later. The study also collects important information on the risk of bleeding, especially bleeds that make the stroke worse, or perhaps are fatal.   For more information about randomised controlled studies see:

 

http://clinicaltrials.gov/ct2/info/understand

 

Informed Consent for IST-3

IST-3 was the first major randomised stroke study to have a period of consumer consultation before finalising the trial design and materials. This period of consultation was extremely useful in ensuring that our information leaflet and process for gaining consent was the best possible, during a period that is always extremely difficult for patients and their families. We have a consumer on our Steering Committee who advises us on aspects of the study which are important to the participants and their families.  The scientific paper describing the consultation work we did before starting the study is available at:

 

http://www.bmj.com/cgi/reprint/325/7361/415

 

When will the results be available?

You can see how well we’re doing on our way to our target of 3100 people in the trial on the website (click on the button which says ‘recruitment’). We hope to complete trial recruitment by mid 2011, with the results released about a year later. We will then publish the main results on this website.

 

Your questions

If you have any questions about your involvement in the trial, or that of your family member, please contact us at: ist3@skull.dcn.ed.ac.uk

 

Unfortunately we will not be able to answer general medical enquiries but we are interested in feedback about IST-3.

 

Author: Richard Lindley

Date: 21st June 2010