Doctors want testing for a new type of ‘bad cholesterol’ – but should you get the test?

Up to five million Australians are unaware they have high levels of Lp(a) cholesterol, which is a high risk for heart attacks. So who should get a test and when?

Professor Jason Kovacic, executive director of the Victor Chang Cardiac Research Institute, says ‘it is very worrying that there could be tens of thousands of Australians who are at increased risk of developing heart disease but are completely oblivious to it’.

There’s been a big push from leading cardiologists this year for everyone to be aware of a “new bad cholesterol” known as lipoprotein (a).

Like the other ‘‘bad’’ cholesterol we all know so much about, LDL (low-density lipoprotein), Lp(a) are particles made up of protein and lipids that carry cholesterol through your bloodstream to your cells.

Unlike the HDL “good cholesterol’’, which carries cholesterol away from your heart to be disposed of, Lp(a) and LDL both carry cholesterol towards the heart, where it can build up and cause plaque to form in the arteries.

“Lipoprotein (a) has been actually known about for decades, but it’s only been in recent years that we now have a very high level of evidence that Lp(a) is a major risk factor for atherosclerosis, which is the hardening and narrowing of the arteries in the heart caused by a build-up of plaque and is the major driver of heart disease,” says Professor Jason Kovacic, executive director of the Victor Chang Cardiac Research Institute.

“It is very worrying that there could be tens of thousands of Australians who are at increased risk of developing heart disease but are completely oblivious to it. We could find these people with a one-off blood test.”

Some of the nation’s most prominent cardiologists are now pushing for the blood test that can determine an individual’s levels of Lp(a) to be publicly funded, warning up to 20 per cent of Australians could be at heightened risk of having a heart attack, but have no idea that was the case.

The blood test is currently available privately and costs only about $40, but because there is such low awareness of Lp(a) and its dangers, few doctors order such a test for their patients.

The other issue is that there is pretty much nothing you can do via exercise or diet to influence your Lp(a) levels – they are determined purely by genetics.

So is there is any point finding out whether you do have elevated Lp(a) levels? Are there any remedies whatsoever available if you fall into a high-risk category?

“We know this is likely to be a far more common risk factor than was previously appreciated,” Professor Kovacic says. “We know that it’s not captured by our standard risk calculators. It’s not captured by a lipid panel. And there are people that are having heart attacks.

“There are currently no specific drugs to treat high levels of Lp(a). But having a test to check levels does identify people who are at additional risk of coronary heart disease, and enables us to double down on conventional risk factors like blood pressure, cholesterol, smoking and diet, and to put really focused effort on to making sure all those other factors are optimally controlled.

“We sort of think about it as offsetting if you like a high Lp(a) level by dealing with all these other cardiovascular risk factors.”

Professor Kovacic says that in the coming years, there are likely to be effective pharmaceuticals available that specifically target Lp(a) and save lives.

Such drugs are in the advanced stages of clinical trials and looking promising. Some doctors perform apheresis – a type of blood filtering to remove the Lp(a) particles – for extremely high-risk individuals but this is rare. Statin medications do not have an effect on Lp(a).

There is also the possibility currently that doctors could use certain off-label drugs but evidence on these remedies is not established.

Obtaining a blood sample for a cholesterol test.

So having the test to establish Lp(a) at this stage in time really boils down to giving doctors the opportunity to aggressively manage the other aspects of the health of high-risk individuals that they can control.

If you’re on top of your risk factors, have well-managed blood pressure and cholesterol, exercise and eat well, there may be no utility at this point in time of discovering that you may have high levels of Lp(a) which you ultimately cannot control – at least until specific drug therapies come along.

Then again, having the test may encourage other family members to also do so if you do discover you are high-risk – and that may end up saving their lives, even if you’re doing everything you can to stay well.

“The real push for Lp(a) testing at the moment, particularly given that we don’t yet have targeted therapies for it, is to conduct it on males below 55 or women below 60 that have a history of unexplained heart attack stroke, or stent implantation or something like that,” Professor Kovacic says.

“If there’s a family history of those things, because if it runs in families, or there’s been an early onset, then I think it’s more likely that it could be an Lp(a) problem, or at least it needs to be seriously considered.

“And those are the ones that, at the moment, were really enthusiastic to test.”