Heart disease: Millions may no longer get preventive statin therapy

As noted by the American Heart Association, “atherosclerotic cardiovascular disease (ASCVD) is caused by the buildup of plaque within the arteries, limiting the flow of blood to important organs.”

Several atherosclerotic cardiovascular disease-related conditions can lead to serious bodily harm, such as heart attacks and strokes.

Sometimes, doctors may prescribe statins to people who are at particular risk for atherosclerotic cardiovascular disease. Statins are also sometimes prescribed to help lower cholesterol levels.

Cheng-Han Chen, MD, a board-certified interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, CA, not involved in the current research explained to Medical News Today that “[s]tatins are commonly used in clinical practice in two scenarios: In people who have already suffered a cardiovascular event such as heart attack or stroke, or in people with risk factors for developing heart disease.”

“For people who have already had a heart attack or stroke, we recommend a ‘high-intensity’ statin, such as atorvastatin or rosuvastatin,” he told us.

“For everyone else, the decision to start a statin depends on our evaluation of their risk for developing cardiovascular disease in the future. This includes an assessment of their risk factors for heart disease, such as a high blood pressure and/or diabetes. To help us decide whether to start someone on a statin, we will frequently use a risk calculator to estimate someone’s 10-year risk of developing cardiovascular disease.”

– Cheng-Han Chen, MD

The researchers who conducted the current study explain that the American Heart Association and American College of Cardiology initially developed pooled cohort equations (PCEs) in 2013.

These equations helped calculate a person’s estimated 10-year risk for atherosclerotic cardiovascular disease. However, these equations may not be entirely accurate, particularly for groups that were underrepresented in the initial cohorts that derived the PCEs.

In 2023, the American Heart Association Cardiovascular-Kidney-Metabolic Scientific Advisory Group developed a new set of equations to predict atherosclerotic cardiovascular disease risk.

This set of equations, the PREVENT equations, does not include race but instead adds in other measurements like kidney function, the social deprivation index, and statin use.

The current cross-sectional study looked at how the PCEs and PREVENT equations differ in risk prediction and recommendations for primary prevention statin therapy.

Researchers used data from the United States’ National Health and Nutrition Examination Survey (NHANES). They included adults aged between 40 and 75 who did not have atherosclerotic cardiovascular disease. The sample size, 3,785 adults, was representative of the U.S. population.

Researchers analyzed the data using both equation groups — PCEs and PREVENT equations — to examine 10-year atherosclerotic cardiovascular disease risk. However, they did not include data on the social deprivation index because this was unavailable through the survey data.

They used the 2019 ACC/AHA guidelines to determine primary prevention statin therapy eligibility criteria. These guidelines recommend statin therapy for adults between forty and seventy-five who have diabetes, high cholesterol levels, or an estimated 10-year atherosclerotic cardiovascular disease risk of 7.5% or more.

They were then able to calculate the number and proportion of U.S. adults who would experience changes in statin recommendations based on the PCEs to PREVENT equation differences.

The study found that the estimated 10-year risk for atherosclerotic cardiovascular disease went from 8% using PCEs to 4.3% using PREVENT equations.

They observed the most drastic difference for Black adults, whose risk went from 10.9% to 5.1%, and adults between 70 and 75, whose risk went from 22.8% to 10.2%. Thus, the use of PREVENT equations could lead to a general shift into lower-risk categories for a number of individuals.

Researchers further estimated that the statin recommendations for U.S. adults would drop from 45.4 million to 28.3 million with a change from PCEs to PREVENT equations. They also noted that many adults eligible to take statins based on PREVENT equations were not taking statins, equating to 15.8 million adults.

This research does have some limitations. First, data from NHANES relies on self-reporting, and not everyone responds to the survey, which can lead to errors.

Data collection also did not note the dosage of statin medications, medication adherence, or changes in HDL cholesterol levels. Furthermore, the researchers did not stratify atherosclerotic cardiovascular disease risk by other risk enhancers, or examine the use of other lipid-lowering therapies.

The researchers did include individuals with certain outlier values for both calculators, even though clinical practice usually excludes these individuals.

Another issue was that the authors were not able to look at LDL cholesterol levels separately in their primary analysis although they did take it into account in sensitivity analyses. Thus, they could have underestimated statin eligibility at the population level.

The researchers note that they could not determine which risk score is most accurate in today’s practice, so more studies are needed to determine the most helpful risk-assessment equations in clinical practice.

They further note that doctors could consider moving away from precise treatment thresholds and towards better risk communication with people.

Chen commented that it could also lead to changing risk thresholds. He explained to MNT that:

“Depending on how future guidelines are written, this could result in fewer patients being recommended statin therapy. As statins are known to be very helpful in preventing cardiovascular disease, any future guidelines may need to adjust the risk thresholds we use for starting statin therapy.”

Regular use of PREVENT equations could also mean doctors utilize additional tests to make recommendations.

Michael Broukhim, MD, a board-certified interventional cardiologist at Providence Saint John’s Health Center in Santa Monica, CA, also not involved in the current research, emphasized that “[t]he potential clinical implications are there may be an increase in cardiovascular and cerebrovascular events if less patients are treated for hyperlipidemia.”

“Utilizing additional testing, such as coronary artery calcium scoring or lipoprotein a testing, may be more important to decide whether patients would benefit from statin therapy,” he advised.