Cholesterol drugs could stop fatal heart rupture in men

Cholesterol-lowering drugs could transform the treatment of abdominal aortic aneurysms (AAAs) and save hundreds of lives every year.

An AAA is a balloon-like swelling of the lower part of the aorta, the body’s main artery that pumps blood from the heart to the rest of the body.

Left untreated, it can grow and burst, causing life-threatening bleeding. About 80 percent of fractures are fatal.

AAA is believed to be caused by changes in the artery wall due to aging, smoking and high blood pressure, but the condition also runs in families.

It is six times more common in men than women and affects about 4 percent of men over 65. Screening – in which an ultrasound probe is passed over the abdomen to create an image of the aorta – is offered to men if they turning 65.

Women are not part of the screening program because of their lower risk.

One theory is that the female sex hormone, estrogen, protects against their development (although, as Good Health has reported, women are diagnosed based on criteria established for men, who are larger, and researchers are now investigating whether women would benefit from revised ‘women-friendly definitions).

Symptoms of AAA include persistent stomach pain, back pain, and a throbbing sensation near the belly button.

However, most cases are asymptomatic.

If a large aneurysm is found, an aneurysm with a diameter of at least 5.5 cm, it can be repaired surgically.

Smaller ones are monitored with regular ultrasound scans.

But there is always a risk that they could burst at any time, and the condition is sometimes described as a ‘ticking time bomb’.

Now a new study suggests that medications already used to lower cholesterol may slow the growth of aneurysms and reduce or even prevent the need for surgery.

For the study, published last month in the journal Nature Genetics, researchers compared the DNA of nearly 40,000 people with AAAs with that of a million people without the condition.

This revealed almost 150 pieces of DNA that are involved in the development of aneurysms.

Crucially, this included a gene that makes a protein called PCSK9.

This protein, made in the liver, ensures that the ‘bad’ LDL cholesterol is not broken down.

As part of the study, studies in mice also showed that AAAs grew more slowly in mice that couldn’t make PCSK9, indicating that drugs that lower PCSK9 levels could be beneficial.

Such drugs, known as PCSK9 inhibitors, already exist and are used to lower cholesterol when existing treatments such as statins are not effective enough.

Two PCSK9 inhibitors, alirocumab and evolocumab, are already licensed for use in Britain, although they have yet to be trialled in AAA patients.

These clinical trials could begin within two years and the drugs could be widely used to treat abdominal aortic aneurysms by 2030, says Matthew Bown, professor of vascular surgery at the University of Leicester and one of the study’s lead investigators.

It is not known how cholesterol stimulates the growth of aneurysms. One possibility, however, is that high cholesterol leads to inflammation that weakens the walls of the aorta.

Commenting on the approach, Professor Gerard Stansby, honorary consultant vascular surgeon at Newcastle upon Tyne Hospitals NHS Foundation Trust, said: ‘AAA is a leading cause of sudden death, especially in men aged 65 or over.

‘Anything that could explain why they develop or slow the rate at which they grow would be extremely useful and potentially save many hundreds of lives each year.’

• Covid could accelerate the growth of abdominal aortic aneurysms, according to a study from Stanford University in the US. Aneurysms are ten times more likely to grow rapidly – ​​by more than 2.7mm per year – in those who have had the virus. One theory is that the virus’s spike protein produces more growth-inducing compounds. Researchers said those monitoring AAAs should be made aware of the connection.