QRC-PVD Clinical Trial - Metformin Aneurysm Trial (MAT)

An abdominal aortic aneurysm (AAA) is the ballooning of part of the aorta in the abdomen. AAAs vary in size but tend to gradually grow larger. Once they reach a size of 5.5cm in diameter, they have a high chance of rupture. The cause of AAA is not known but there are some risk factors such as history of smoking, age and being male.

Currently, there are no effective drug treatments available for AAA. However, research suggests that a drug called metformin (which is used to lower blood sugar levels in people with type 2 diabetes) may reduce the risk of adverse AAA events such as AAA repair and AAA rupture. A large clinical trial is needed to test this. Metformin is a safe, well-tolerated drug that is suitable for use in a range of populations (including people without diabetes). The main aim of this clinical trial is to test if metformin reduces the risk of adverse AAA events (i.e., AAA repair or rupture).

Recruitment Status


Ethics Approval

Human Research Ethics Approval

Participants will have an initial Screening Visit to confirm eligibility and review health and medical history. Following successful screening, participants will be randomised to either the active metformin study medication or a placebo and continue taking the study medication for approximately three and a half years. Over this time, participants will be regularly followed up by their study coordinator every three months, over the phone, and annually in person if possible. Participants in MAT will also have their routine imaging (i.e. ultrasounds from their treating hospital) collected, and repeat blood tests on occasion.

  • Eligibility review
  • Health and medical history
  • Quality of life

1-2 hours

Week 2 Phone call check in with study coordinator 10-15 minutes
Week 6 Phone call check in with study coordinator 10-15 minutes
Week 6 Phone call check in with study coordinator 10-15 minutes
RandomisationNo in person visit - Study medication posted 
3 monthsPhone call check in with study coordinator

10-15 minutes

6  monthsPhone call check in with study coordinator
New study medication posted

1-2 hours

12 months

Health check-up:

  • Ultrasound
  • Blood test
  • Quality of Life questionnaires

1-2 hours

The above study schedule, from 3 months will repeat for the duration of participation (typically 3.5 - 4 years).

How to participate

Participant Information Flyer and Consent Forms

Register your interest in participating in this study.