RecruitingPhase 3Phase 4ACTRN12618001707257

The Metformin Aneurysm Trial

Sponsor

James Cook University

Enrollment

1,954 participants

Start Date

Feb 8, 2021

Study Type

Interventional

Conditions

Abdominal Aortic Aneurysm (AAA)

Summary

MAT is a multicentre, randomised, placebo-controlled trial to assess if 1500 mg of metformin per day will reduce Abdominal Aortic Aneurysm (AAA)-related events in patients with small AAAs who do not have diabetes. In order to allow reliable assessment of any beneficial effects of metformin on important AAA outcomes, including repair or AAA mortality, follow-up will occur until 616 primary outcome events have been accrued (estimated to require a median of ~3.5 years follow-up). In order to study 1,954 people with small AAA for ~3.5 years at low cost, MAT is streamlined to minimise extra work on collaborating doctors and hospitals. Only essential data will be collected and entered directly into a database. If it can be reliably demonstrated that metformin reduces the risk of AAA events in people with small AAA who do not have diabetes, then this would be relevant to some tens of millions of people worldwide who are currently receiving no treatment of their AAA. This important international study is being led by the Central Coordinating Centre at the Queensland Research Centre for Peripheral Vascular Disease.

Eligibility

Sex: Both males and femalesMin Age: 18 Yearss

Plain Language Summary

Simplified for easier understanding

An abdominal aortic aneurysm (AAA) is a bulge in the main blood vessel that runs through the abdomen. When the bulge is small (under 5.5 cm), doctors typically monitor it rather than operate. However, these aneurysms can slowly grow and eventually become life-threatening. This large international trial is testing whether metformin — a very safe, widely used diabetes medication — can slow the growth of small AAAs and reduce the need for surgery or the risk of rupture in people who do not have diabetes. Laboratory and observational studies have suggested that metformin may have anti-inflammatory effects that could help stabilise the aortic wall. Participants will take either 1,500 mg of metformin daily or a placebo for approximately 3.5 years, with follow-up visits to track their aneurysm and overall health. You may be eligible if you are 18 or older, have a small AAA (35 mm or larger) that your doctor has decided does not need immediate repair, and do not have diabetes. People with significant kidney impairment, severe heart failure, or a known allergy to metformin are not eligible to participate.

This summary was AI-generated to explain the trial in plain language. It is not medical advice. Always discuss eligibility with your doctor before enrolling in a clinical trial.

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Interventions

Study Design: Parallel group, blinded, placebo-controlled randomized clinical trial. INTERVENTION - metformin extended release: three 500mg capsules per day (1500mg/day). Pre-randomisation Run-In

Study Design: Parallel group, blinded, placebo-controlled randomized clinical trial. INTERVENTION - metformin extended release: three 500mg capsules per day (1500mg/day). Pre-randomisation Run-In Titration (-6-0 weeks): Participants in both arms undergoe a single blinded 6-week pre-randomisation run-in as a part of the screening process. Week 1 - 2: one 500mg capsule per day (~500mg/day). Week 3 - 4: two 500mg capsules per day (~1000mg/day). Week 5 - 6: three 500mg capsules per day (~1500mg/day). Capsules are consumed together once a day. After randomisation follow-up (approximately 3.5 years post titration period): participants will continue to take 1500mg/day until the end of the trial which is expected to be around 3.5-years. Compliance with study treatment will be reviewed by asking participants how regularly they take the study treatment (every day [about 100%], nearly every day [about 80-99%], some days [about 40-79%], a few days [about 10-39%], almost never [about 1-9%] or never [0%]). Participants will also asked at each follow-up how many tablets are remaining.