Heart health month: What we know about lipoprotein (a)

For decades, doctors have encouraged patients to monitor their cholesterol levels, with studies showing that heart disease risk increases with high levels of low-density lipoprotein (LDL), also known as the “bad cholesterol,” and not enough high-density lipoprotein (HDL), also known as the “good cholesterol.”

Diet, exercise, and medications like statins can help people regulate their good and bad cholesterol levels.

But now, doctors are recognizing the importance of a third type of cholesterol -- lipoprotein (a).

Lipoprotein (a) has been increasingly recognized as a standalone predictor for cardiovascular disease due to its inflammatory properties that accelerate clot formation in the blood vessels.

Scientists are still learning more about lipoprotein (a). Testing is available but not universally recommended. For now, drugs to treat high levels are not available, but may soon be on the horizon.

But, for anyone whose parents, grandparents, or relatives have developed heart disease at a young age, doctors say it’s important for everyday people to ask their doctors about lipoprotein (a), which may be a culprit.

Should I ask for my lipoprotein (a) levels to be checked, and is it covered by insurance?

“Anyone who has a strong family history of heart disease or has had evidence of heart disease that is premature -- that is, before the age of 55 in men and before 65 years of age in women -- should consider lipoprotein (a) testing,” Chair in Preventative Cardiology and Professor of Medicine at Tulane University School of Medicine in New Orleans, Louisiana, Dr. Keith Ferdinand, says. "[It] may be a good way to predict if you are at increased risk beyond the conventional lipid panel.”

Lipoprotein (a) testing can also be measured in those whose cholesterol levels do not improve with standard cholesterol-lowering medications, says Associate Professor of Medicine at Beth Israel Deaconess Medical Center in Boston, Dr. Stephen Juraschek.

The American Heart Association supports once-in-a-lifetime measurement of lipoprotein (a) in people at risk for cardiovascular disease, differing from practice guidelines across Europe and Canada, which recommend measuring lipoprotein (a) at least once in all adults.

As a result, some insurance plans do not cover lipoprotein (a) testing. Be sure to talk to your doctor about whether lipoprotein (a) testing is appropriate for you.

What can I do if my lipoprotein (a) levels are high?

“Unfortunately, there is no treatment available,” says Ferdinand.

But doctors say knowledge is power -- and people with high levels can take other steps to lower their heart disease risk.

For example, efforts should be made to lower LDL to a target level with cholesterol-lowering medications, according to Juraschek. People should also focus on improving “blood pressure, avoidance of smoking, weight loss, physical activity and control of blood glucose levels,” says Ferdinand.

What treatment options are on the horizon to improve lipoprotein (a) levels?

“There are studies now looking at two different medications that specifically target one of the proteins involved in production of lipoprotein (a), and we probably won’t have the results of those clinical trials for another 2-3 more years,” says Professor of Cardiology and Director of the Johns Hopkins Ciccarone Center for the Prevention of Cardiovascular Disease in Baltimore, Maryland, Dr. Roger Blumenthal.

There are eight ongoing clinical trials investigating novel drugs that directly target how lipoprotein (a) is made on a molecular level. All but one of the ongoing trials are using an injectable form of these novel drugs that are administered subcutaneously, or underneath the skin. “Some of the most advanced of these therapies are in stage 3 trials, which will be needed prior to FDA approval,” says Juraschek.

“Although lipoprotein (a) cannot be lowered through lifestyle modifications, this does not dismiss the importance of building healthy habits,” says Associate Professor of Cardiology and Director of the Preventive Cardiovascular Health Program, Yale School of Medicine in New Haven, Connecticut, Dr. Erica Spatz. “Committing to a regular exercise routine and eating a more plant-forward diet can significantly reduce total cardiovascular risk, which is even more important if lipoprotein (a) is elevated.”

Jennifer Miao, M.D., is a fellow physician in cardiology at Yale School of Medicine/Yale New Haven Hospital, and a member of the ABC News Medical Unit.