An aneurysm or enlargement of the abdominal aorta – the major artery that runs through the belly to the legs – can rupture and cause life-threatening blood loss or death. Abdominal aortic aneurysms (AAA) affect around 20 million people worldwide.
In Australia, the incidence and mortality from these aneurysms is four times higher than the world average. Around 2000 people dying from rupture or surgery to repair the aneurysm each year, according to Dr Joseph Moxon, senior research fellow at the College of Medicine and Dentistry and AITHM.
He is one of the investigators in a trial planned to involve 1,954 people in several countries to test if a drug can reduce the need for surgery.
The trial, led by the Queensland Research Centre for Peripheral Vascular Disease in collaboration with the George Institute is being funded with $4,997,533 from the National Health and Medical Research Council. The Australian researchers are working in collaboration with investigators in New Zealand, Sweden and the United Kingdom.
Dr Moxon, senior research scientist at the centre, says abdominal aortic aneurysms are part of the larger problem of peripheral vascular disease (PVD) that affects around 10% of adults in Australia. Dr Moxon is also involved in identifying novel therapeutics that could limit inflammation and improve blood supply in people with other forms of PAD, such as lower limb artery blockage.
Current guidelines recommend that surgery is considered for all symptomatic aneurysms. But most aneurysms do not cause symptoms. In these asymptomatic cases, surgery is considered only when aneurysms reach 55 mm or larger in men and 50 mm or more in women.
Dr Moxon says people with aneurysms below this threshold have to keep going back and forth to hospitals to be assessed, usually by ultrasound, until their aneurysms grow to the threshold size for surgery. ’This is certainly inconvenient for patients and it is also associated with quite a significant burden mentally and it reduces health-related quality of life.’
Dr Moxon says: “Currently there are no drugs that have been shown to be beneficial for abdominal aortic aneurysms. What’s strange about aneurysms, is that unlike artery blockage, there is a negative relationship between diabetes and artery weakening. It has been suggested that diabetes drugs may be responsible for this.”
The planned placebo-controlled trial will test a diabetes-related drug. If this drug can prevent surgery for aneurysms, it could substantially benefit a large number of people around the world.