When it comes to monitoring cholesterol, there’s a new standard in town.
For the first time since 2018, clinical guidelines for screening and monitoring cholesterol have changed thanks to American College of Cardiology and the American Heart Association.
And the guidelines are significantly lower than before.
Focusing on low-density lipoprotein, the “bad” cholesterol, the new targets are less than 100 mg/dL for those without known cardiovascular risk; less than 70 mg/dL for those at intermediate risk; and less than 55 mg/dL for those at high risk. That’s down from less than 100 mg/dL previously considered optimal.
Risk factors include a family history of heart attack, smoking and diabetes.
The recommendations concern LDL-C, which contributes to atherosclerosis, or hardening of the arteries. Even a moderate buildup of plaque can block blood flow and cause a stroke or heart attack.
People are also reading…
“Guidelines are part of what we do in medicine,” says Dr. Tamar Polonsky, a cardiologist with UChicago Medicine who coauthored the new cholesterol standards. “Since 2018 there has been so much that's happened in cardiology: New trials, newer drugs, more understanding of things like lipoprotein-a. Everything evolved, and it's a good time to take stock and think how the data impacts our patients.
“We save for retirement. We floss our teeth. We get mammograms. We have really good data now that if we take that preventive mindset, then we are also going to prevent a lot of cardiovascular disease,” says Polonsky.
Though the new guidelines include HDL, high-density lipoprotein or “good” cholesterol, it’s relegated to a part of a person’s overall cholesterol score as properties considered beneficial are re-examined.
More than the numbers, the update includes a calculator, PREVENT-ASCVD, that determines 10- and 30-year risk estimates for heart attacks and stroke based on a study of 6.6 million people. A previous calculator projected only a 10-year risk from a smaller sample pool.
“PREVENT-ASCVD goes beyond previous risk calculators by including kidney function, diabetes and body mass index (BMI) and better reflects our growing understanding of how these other factors contribute to developing heart disease over the lifetime,” says Dr. Ryan Lahey, a cardiologist at Bluhm Cardiovascular Institute at Northwestern Medicine Palos Hospital.
He recommends testing for long-term risk starting at age 30. “If there's a family history of early cardiovascular disease (before age 55 in a male relative, age 65 in a female relative), severe high cholesterol or familial hypercholesterolemia, screening should start earlier.”
Familial hypercholesterolemia is fairly common – present in about 1 in 250 people – and treatable. “That is extremely high cholesterol, in people who have LDLs above 190 since childhood. That's a subgroup of people who can have heart attacks in their 20s and 30s and 40s. So, the point is if we treat it now, we can restore their risk to (that of) someone who wasn't born with that genetic issue.
“We have more tools in our toolbox to control cholesterol levels,” Lahey says of treatment options. “For patients who cannot tolerate statin medications or whose cholesterol levels do not reach goal with this first-line therapy, additional oral and injection medications can be used.”
The new guidelines recommend additional tests to determine the best treatment.
For those in the intermediate range, Polonsky recommends a coronary artery calcium test to determine whether a statin is needed. “You do it with a CAT scan,” she says. “You're looking for calcium deposits. It's semi-automated and you can calculate a calcium score. With increasing amounts of calcium in the arteries, the risk of a stoke is higher and there are percentiles to adjust for age and sex.
“If they don't have calcium, their risk is lower for the next 10 years. They can focus on diet and exercise.”
A person who has had a stroke or heart attack needs a statin, which Lahey says lowers LDL by targeting liver cholesterol metabolism.
“Generally, statins do not get rid of plaque that has already deposited in blood vessel walls,” he says. “However, aggressive and sustained LDL lowering can stabilize existing plaque, making it less likely to rupture and cause a heart attack, and prevent it from progressing.”
Smokers, diabetics and those who have a strong family history of heart attack or stroke are tend to build calcium faster on average, says Polonsky.
The biomarker LPL-a is another factor to consider. “Lipoprotein-a (LPL-a) is a different type of protein particle,” says Polonsky. “It's a plaque buildup less influenced by diet and exercise.”
Numbers above 125 are considered abnormal on a scale that goes up to 500, 600. “It's not that every single person who is above 125 is high risk,” she says. “The risk rises when other medical problems are involved.”
Besides pursuing a healthy lifestyle, patients with an LPL-a score of 250-300 should start medication, and in some cases aspirin, sooner. “What LPL-a does in addition to increasing inflammation in the arteries is make them more likely to build up plaque” at least doubling the risk of a heart attack, Polonsky says.
It's never too late to work on your cholesterol profile, Polonsky says noting that lifestyle changes including improved diet and added exercise are a good start. “We are not here to put everybody on statins, but we have to acknowledge for the vast majority of people who are high risk, we have treatment that can lower their risk and for the vast majority, it’s safe.”
