Last month, the American College of Cardiology and other medical organisations released new guidelines to help patients and doctors know what cholesterol levels to aim for, and which medications might help. We asked doctors to break down the recommendations.

The guidelines recommend that adults, starting at age 19, have their cholesterol checked at least every five years.

A lipid panel, which you can have done with a blood draw at your primary care doctor’s office, looks at several types of cholesterol. Of these, doctors focus most on low-density lipoprotein or LDL, a “bad cholesterol” that can build up on your artery walls. We have “overwhelming evidence” that the lower your LDL levels, the lower your risk of a cardiovascular event like a heart attack or a stroke, said Dr Erin D. Michos, associate director of preventive cardiology at Johns Hopkins University School of Medicine, US.

The guidelines also recommend that all adults now have levels of lipoprotein(a), a genetically determined form of cholesterol, tested at least once. Lp(a) increases the risk of heart disease, regardless of your other lipid levels.

“It’s an amplifier of whatever your risk is,” said Dr Ann Marie Navar, an associate professor of cardiology at the University of Texas Southwestern Medical Center in Dallas, US. We reach our adult levels in childhood, and they remain relatively stable over a lifetime, with only a few exceptions.

There’s another, less widely used test for a different lipoprotein called ApoB. This is perhaps the best measure of cholesterol-related risk, Dr Navar said, because it reflects the total number of “bad” cholesterol particles, including not just LDL but also Lp(a) and another type called vLDL. This makes it a more reliable measure, especially for people with metabolic disease, including diabetes and cardiovascular-kidney-
metabolic syndrome, because of differences in LDL particle size and density in these patients.

Determine your individual risk. It’s never too early to talk to your doctor about your risk of heart disease, and you should build heart-healthy habits. But starting at age 30, the conversation can include an actual prediction of your future risk. The guidelines use a new calculator, called PREVENT, that includes risk factors that weren’t previously taken into account, including body mass index and kidney disease.

It assesses both short-term (10-year) and long-term (30-year) risk.

Measuring long-term risk is particularly useful for people aged 30-59. Doctors might look at a younger patient who isn’t at risk of heart disease in the next 10 years but could be in the long-term, and recommend that they start taking a statin.

“We want to reduce their lifetime exposure” to these bad cholesterol particles, Dr Michos said. “The risk is not only how high a level is, it’s how many years one’s arteries are exposed to these high levels,” similar to how doctors look at “pack-years” of smoking.

People who are at low 10-year risk don’t typically need to start medication, unless they have an LDL level of 160 mg/dL or greater, or have a high 30-year risk.

For people who are at borderline or intermediate risk, a coronary arterial calcium (CAC) score — which uses a low-dose CT scan to look for evidence of plaque buildup in the heart arteries — can help with decision making. That evidence can be a powerful motivator for asymptomatic patients to take medication, said Dr Martha Gulati, a professor of cardiology at Houston Methodist DeBakey Heart & Vascular Center, US.

In considering treatment, doctors also take into account other factors that might raise
a person’s risk of heart disease, such as South Asian race, diabetes, early menopause, pre-eclampsia or gestational diabetes. They also consider inflammatory conditions such as rheumatoid arthritis and psoriasis, since inflammation contributes to plaque buildup in the arteries.

The new guidelines give specific target levels of LDL based on short and long-term risk of heart disease.

• For general prevention of heart disease in people who are at borderline or intermediate 10-year risk and don’t have diabetes or heart disease, the goal is an LDL level under 100 mg/dL
• For patients at high 10-year risk, people with long-standing type 2 diabetes or complications of diabetes, or people with CAC scores over 100, the goal is under 70 mg/dL
• For most patients who have had a heart attack or a stroke, the goal is under 55 mg/dL.

Most patients with continuously high cholesterol levels will need medication. Statins, which block the liver from making cholesterol, are still the first line of treatment. “They’re cheap,” Dr Gulati said. “We’ve had them for over four decades. They reduce bad cardiovascular outcomes.”

NYTNS