CompletedObservational

Magnetic resonance imaging (MRI) for abdominal aortic aneurysms to predict rupture or surgery: the MA3RS trial

The aorta is the main blood vessel carrying blood from the heart to the rest of the body. In some people, the aorta swells in the tummy area, forming an abdominal aortic aneurysm. These usually grow slowly without symptoms, but if they get too large, they can burst or require surgery. Currently, the NHS uses ultrasound scans to monitor aneurysms. This study is testing whether a special magnetic resonance imaging (MRI) scan is better at predicting which aneurysms are at risk. The scan uses an iron-based liquid called ferumoxytol to highlight active 'hotspots' of inflammation in the blood vessel wall. Participants take part for two years. During this time, they have MRI and CT scans alongside their regular clinic checks to see if this new imaging technique can help doctors give more personalised care in the future.

At a glance

Status

Completed

Sponsor

University of Edinburgh / NHS Lothian (UK)

Enrolment target

350

Start

07 Sep 2012

Estimated completion

07 Sep 2016

Abdominal Aortic Aneurysm

What is this study about?

The aorta is the largest artery in your body. In some people, a section of the aorta in the tummy weakens and balloons outward. This is known as an abdominal aortic aneurysm (AAA). Most aneurysms develop slowly and do not cause any day-to-day symptoms. However, if an aneurysm becomes too weak, it can burst, which is a life-threatening emergency. Because of this, doctors keep a close eye on them to decide if or when surgery is needed.

At present, doctors track the size of aneurysms using ultrasound scans. While ultrasound is safe and simple, it only measures how wide the bulge is. It cannot show what is happening inside the blood vessel wall itself. Researchers have found that certain immune cells gather in weakened parts of the artery wall, creating 'hotspots' where the aneurysm may be expanding faster or becoming fragile.

This trial, called the MA3RS study, is testing whether a special type of MRI scan can detect these hotspots. Participants receive an injection of ferumoxytol, a medicine containing tiny iron particles that are taken up by these immune cells. The MRI scanner can then clearly show where these cells are gathered. By tracking patients over two years, researchers hope to prove whether this scan can accurately predict which aneurysms are likely to burst or need surgery, allowing doctors to protect patients better in the future.

Key takeaways

The study tests whether specialised MRI scans can better predict when an aneurysm might grow or burst.
It involves two hospital visits at the start, followed by routine six-monthly checks and a final CT scan at two years.
Participants receive an iron-based dye to highlight inflammation inside the blood vessel wall.
Your routine NHS ultrasound monitoring will continue as normal throughout the study.
Taking part is completely voluntary and you can stop at any time.

Who may be eligible?

You may be able to join this study if you are 40 years of age or older and have an abdominal aortic aneurysm that measures at least 40 millimetres (4 centimetres) across on an ultrasound scan.

You will not be able to take part if you already need urgent surgery for your aneurysm, or if you have a medical device such as a heart pacemaker or metal implant that makes an MRI scan unsafe. The study is also not suitable for women who are pregnant, breastfeeding, or able to have children.

In addition, people with serious kidney disease, high levels of red blood cells, conditions causing excess iron in the body (such as hemochromatosis), or known allergies to the dyes used in the scans will not be able to join.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

I am aged 40 or over.
I have been diagnosed with an abdominal aortic aneurysm measuring at least 40 mm (4 cm).
I do not have a pacemaker, metal implant, or other condition that makes MRI scans unsafe.
I do not have severe kidney problems or known iron overload disorders.
I am not pregnant, breastfeeding, or planning a pregnancy.

Answer every question to see your result.

What does participation involve?

Taking part in the study lasts for about two years. At the start, you will visit the hospital on two consecutive days. On the first day (lasting about three hours), the team will review your medical history, take a small blood sample (about four teaspoons), and check your blood pressure. You will have an MRI scan and a CT scan. Before the scans, you will receive two injections through a small tube (drip) in your arm: Buscopan to calm your bowel movements so the picture is clear, and a standard dye for the CT scan. You will also receive the iron-based liquid (ferumoxytol), after which your blood pressure will be monitored for 30 minutes.

On the second day, you will return for a 40-minute visit to have another MRI scan. On one of these days, researchers will also test the stiffness of your arteries by measuring blood pressure in your arm and leg (you will need to avoid food and caffeine for 4 hours, and alcohol for 24 hours, before this test). You will continue having your usual NHS ultrasound scans every six months, with a small extra blood test and artery stiffness check added to these visits. At the two-year mark, you will have a final CT scan to see how your aneurysm has changed.

Potential risks and benefits

Taking part will not directly cure your aneurysm, but it may help doctors improve care and monitoring for people with aneurysms in the future. The scans and medications are generally very safe. MRI scans do not use radiation. A CT scan uses a small amount of X-ray radiation, roughly equal to two to three years of natural background radiation from the environment. Side effects from the injected medications are uncommon and usually mild, such as a temporary dry mouth, nausea, headache, or mild tummy ache. Very rarely, allergic reactions can happen, and medical staff will monitor you closely to treat any issues. Your participation is entirely voluntary, and you can withdraw at any time without your regular NHS medical care being affected.

Locations (1)

University of Edinburgh
Approximate
Edinburgh, Scotland

Common questions

Will this study replace my normal ultrasound checks?

No. You will continue to have your routine NHS ultrasound scans every six months just as you normally would.

Does an MRI scan hurt?

No, MRI scans are completely painless. The machine can be quite noisy, but you will be given earplugs or headphones, and you will need to lie still while the pictures are taken.

What is the ferumoxytol injection?

Ferumoxytol is an iron medicine normally used to treat iron deficiency. In this study, it acts as a dye that helps the MRI scanner highlight inflammation in your blood vessel wall.

What happens if the scan finds another health issue?

If a scan shows an unexpected finding, the study team will discuss it with you and arrange any follow-up tests or care with your GP or hospital specialist.

Can I leave the study if I change my mind?

Yes. You can leave the study at any point without giving a reason, and your normal NHS treatment will not be affected in any way.

How to find out more

David Newby

d.e.newby@ed.ac.uk +44 (0)131 242 6515 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.