New cholesterol guidelines released by the American Heart Association
New cholesterol guidelines advise doctors to start screening and treating people in their 30s, well before the risks of heart attacks and strokes become significantly higher.
For the first time, the American Heart Association, along with the American College of Cardiology and other medical groups, are also recommending screening for two blood biomarkers associated with heart risks.
The updated guidelines were jointly published Friday in Circulation and the Journal of the American College of Cardiology.
The guidelines – the first overhaul since 2018 – focus on controlling dyslipidemia, or abnormal levels of blood lipids such as cholesterol and triglycerides.
One in four American adults has high LDL, or “bad,” cholesterol, a form of dyslipidemia and a risk factor for heart attack and stroke, according to estimates from the Heart Association.
“We’re trying to help clinicians and patients decide: When should you consider medicine? said Dr. Roger Blumenthal, chair of the guideline writing committee and director of the Johns Hopkins Ciccarone Center for the Prevention of Cardiovascular Disease in Baltimore. “We always want to try to improve our lifestyle habits with each visit, but sometimes medications can be very helpful if lifestyle isn’t enough.”
Dr. Christopher Kramer, a cardiologist at UVA Health Heart and Vascular Center in Charlottesville, Virginia, said the most important takeaway from the new guidelines is that heart disease prevention needs to start earlier. Kramer is also president of the American College of Cardiology, but was not on the guideline writing committee.
“We are changing the way we measure risk,” he said. “It’s not just about assessing the risk over 10 years, but also over 30 years, which means it’s a lifelong disease.”
Reduce LDL cholesterol for life
For patients in their 30s, doctors are now encouraged to use a new calculator, PREVENT, to determine the risk of developing atherosclerotic cardiovascular disease, a type of heart disease caused by plaque buildup in the arteries.
The PREVENT tool, which takes into account factors such as body mass index, cholesterol levels and smoking, calculates 10-year risk for people aged 30 to 79 and 30-year risk for people aged 30 to 59. The updated 10-year risk categories are:
- Low: less than 3%
- Limit: 3% to less than 5%
- Intermediate: 5% to less than 10%
- High: 10% or more.
Blumenthal said the new guidelines will be especially important for people who smoke tobacco, have high blood pressure, high blood sugar, type 2 diabetes or a family history of heart disease.
“It gives them some context about the importance of whether or not they need to be more aggressive earlier in lifestyle changes,” he said.
The guidelines recommend statins, a type of medication designed to lower cholesterol, for adults 30 and older with an LDL cholesterol level of 160 milligrams per deciliter of blood or higher.
Dr. Steven Nissen, academic director of the Cleveland Clinic Sydell and the Arnold Miller Family Heart, Vascular and Thoracic Institute, said early intervention aims to limit long-term exposure to LDL cholesterol.
“The average value of your LDL cholesterol level over your lifetime is one of the strongest indicators of whether you’re going to have a cardiac event,” said Nissen, who was not on the guideline writing committee. “It’s really about reducing lifetime risks, not 10-year risks.”
He said previous versions of the guidelines were too conservative. He is happier with the new recommendations, which advise doctors to consider LDL-lowering therapy for patients at borderline or intermediate 10-year risk of heart disease.
“It’s a lot lower than it’s ever been,” Nissen said. “What they’re basically saying is that you shouldn’t rule out treating someone who only has a 3% risk over 10 years if their lifetime risk is high.”
Clear LDL targets
Dr. Karol Watson, director of the UCLA Health Women’s Cardiovascular Center, co-wrote a commentary published in Circulation alongside the new guidelines, which she called an expansion of the previous version.
“This is not a radical change; we continue to manage lipids to reduce atherosclerotic events,” she said. “As a preventative cardiologist, I can tell you that this is the best strategy we have ever had to prevent heart attacks, strokes and cardiovascular deaths. »
The new guidelines provide “a more precise, individualized and equitable approach” to heart disease prevention, Watson wrote in the commentary.
The guidelines bring back clear targets for LDL cholesterol. For most people without risk factors, doctors now aim for LDL levels below 100 mg/dL.
For people at high risk, the goal drops below 70 mg/dL. For patients who already have heart disease, the goal gets even lower, below 55 mg/dL.
Research shows that people with heart disease experience fewer heart attacks and strokes when treated with a target LDL level below 55 mg/dL.
However, individual cholesterol tolerance can vary, Watson said, citing one of his active 70-year-old patients who had always had low cholesterol but still suffered a mini-stroke.
“Everyone knows someone who had extremely high cholesterol and lived to be 90,” she said. “Every individual has their own level at which their arteries allow their arteries to let in cholesterol.”
Additional biomarker tests
The new guidelines also suggest testing for apolipoprotein B (apoB), a protein that attaches to harmful fat particles in the blood, once a patient reaches their LDL goal. The apoB protein is found on the surface of harmful lipoproteins like LDL that contribute to heart disease.
Previous guidelines did not recommend routine testing for apoB as part of cholesterol screening except for certain patients with elevated triglycerides.
“This could be yet another target for further lipid reduction, because lowering apoB is associated with reduced risk,” Kramer said.
In particular, apoB testing can paint a clearer picture of risk for people with high triglycerides, type 2 diabetes, or cardiovascular-kidney-metabolic syndrome.
Everyone needs an Lp(a) test – once
Also new this year is the recommendation that everyone have a lipoprotein(a) test at least once as an adult. Lp(a) is a type of cholesterol that is not detected by routine tests but is estimated to affect 64 million people in the United States. It is determined by genetics and little affected by changes in diet or exercise.
People with high Lp(a) levels are at extremely high risk of cholesterol buildup in their arteries.
“This should be considered a risk-increasing factor,” Nissen said. “If your levels are high, that means you may want to treat more intensely, even if the LDL level isn’t as high as expected.”
Lp(a) is measured in nanomoles per liter. A level above 250 nmol/L roughly equates to a two-fold increased risk of heart disease, while a level above 430 nmol/L indicates a four-fold increased risk.
“There are currently no treatments available to lower Lp(a), so a lot of people wonder, ‘Well, why am I testing for it?’” Watson said. “The main reason is to get a better overall risk assessment. »
The new guidelines also recommend screening for calcium buildup in the coronary arteries in men aged 40 and older and women 45 and older who are at borderline or intermediate 10-year risk of heart attack or stroke.
Regardless of the change in screening guidelines, the risk factors for heart disease remain the same.
“It’s cholesterol, blood pressure, diabetes, smoking, obesity,” Kramer said. “People need to focus on reducing their risk factors and let their doctors worry about crunching the numbers and deciding whether or not they need to lower their cholesterol levels.”
Heart disease is the leading cause of death worldwide. In the United States, it kills every 34 seconds, according to the Heart Association. Yet the organization also estimates that up to 80% of heart disease and stroke can be prevented through lifestyle changes.
“If you wait until people are 55 or 60, a lot of the damage has already been done,” Nissen said. “They have plaques in their coronaries and it is difficult to resolve the problem.
