'Conservative' USPSTF Primary Prevention Statin Guidance Finalized

August 24, 2022

Questions about how to prescribe statins for primary prevention abound more than three decades after the drugs swept into clinical practice to become a first-line medical approach to cutting cardiovascular (CV) risk. Statin usage recommendations from different bodies can vary in ways both limited and fundamental, spurring the kind of debate that accompanies such a document newly issued by the United States Preventive Services Task Force (USPSTF).

The document, little changed from the draft guidance released for public comment in February, was published online August 23 in the Journal of the American Medical Association and the USPSTF website. It replaces a similar document issued by the task force in 2016.

The guidance has much in common with, but also sharp differences from, the influential 2018 guidelines on blood cholesterol management developed by the American College of Cardiology (ACC), American Heart Association (AHA), and 10 other medical societies.

And it is provocative enough to elicit at least four editorials issued the same day across the JAMA family of journals. They highlight key differences between the two documents, among them the USPSTF guidance's consistent, narrow reliance on 7.5% and 10% cut points for 10-year risk levels as estimated from the ACC/AHA pooled cohort equations (PCE).  

The guidance pairs the 10-year risk metric with at least 1 of only 4 prescribed CV risk factors to arrive at a limited choice of statin-therapy recommendations. But its decision process isn't bolstered by coronary artery calcium (CAC) scores or the prespecified "risk enhancers" that allowed the ACC/AHA-multisociety guidelines to be applied broadly and still be closely personalized. Those guidelines provide more PCE-based risk tiers for greater discrimination of risk and allow statins to be considered across a broader age group.

The USPSTF guidance's evidence base consists of 23 clinical trials and three observational studies that directly compared a statin to either placebo or no statin, task force member John B. Wong, MD, Tufts University School of Medicine, Boston, Massachusetts, told theheart.org | Medscape Cardiology.

"In either kind of study, we found that the vast majority of patients had one or more of four risk factors — dyslipidemia, hypertension, diabetes, or smoking. So, when we categorized high risk or increased risk, we included the presence of one or more of those risk factors," said Wong, who is director of comparative effectiveness research at Tufts Clinical Translational Science Institute.

"Sensible and Practical"

The USPSTF guidance applies only to adults aged 40-75 without CV signs or symptoms and recommends a statin prescription for persons at "high risk," that is with an estimated 10-year PCE-based risk for death or CV events of 10% or higher plus at least one of the four risk factors, a level B recommendation.

It recommends that "clinicians selectively offer a statin" to such persons at "increased risk," who have at least one of the risk factors and an estimated 10-year risk for death or CV events of 7.5% to less than 10%, a level C recommendation. "The likelihood of benefit is smaller in this group" than in persons at high risk, the document states.

"These recommendations from the USPSTF are sensible and practical," states Salim S. Virani, MD, PhD, DeBakey Veterans Affairs Medical Center, Houston, Texas, in a related editorial published the same day in JAMA Network Open. He calls the former B-level recommendation "a conservative approach" and the latter C-level recommendation a "nuanced approach."

Both are "understandable" given that some studies suggest that the PCE may overestimate the CV risk, Virani observes. "On the other hand, statin therapy has been shown to be efficacious" at 10-year CV-risk levels down to about 5%.

The USPSTF document "I think is going to perpetuate a problem that we have in this country, which is vast undertreatment of lipids," Eric D. Peterson, MD, MPH, University of Texas Southwestern Medical Center, Dallas, told theheart.org | Medscape Cardiology.

"We have a ton of good drugs that can lower cholesterol like crazy. If you lower cholesterol a lot, you improve outcomes," he said. Dyslipidemia needs to be more widely and consistently treated, but "right now we have a pool of people in primary prevention who undertreat lipids and wait until disease happens — and then cardiologists get engaged. That's an avoidable miss," Peterson adds. He and JAMA Cardiology associate editor Ann Marie Navar, MD, PhD, provided JAMA with an editorial that accompanies the USPSTF guidance.

"My own personal bias would be that the [ACC/AHA-multisociety guidelines] are closer to being right," Peterson said. They — unlike the USPSTF guidance — cover people with risk levels below 7.5%, down to at least 5%. They allow risk enhancers like metabolic syndrome, inflammatory diseases, or family history into the decision process. "And they're more aggressive in diabetes and more aggressive in older people," he said.

Higher Threshold for Therapy

The USPSTF guidance also explicitly omits some high-risk groups and makes little accommodation for others who might especially benefit from statins, several of the editorials contend. For example, states a related JAMA Cardiology editorial published the same day, "The USPSTF does not comment on familial hypercholesterolemia or an LDL-C level of 190 mg/dL or higher," yet they are covered by the ACC/AHA-multispecialty guidelines.

In addition, write the editorialists, led by Neil J. Stone, MD, Northwestern University, Chicago, Illinois, "the USPSTF uses a slightly higher threshold for initiation of statin therapy" than was used in the ACC/AHA-multisociety guidelines. USPSTF, for example, calls for 10-year risk to reach 10% before recommending a statin prescription.

"One concern about the USPSTF setting the bar higher for statin initiation is that it reduces the number of young patients (age 40-50 years) at risk for premature myocardial infarction considered for treatment," write Stone and colleagues.

That may be related to a weakness of the PCE-based decision process. "Because the PCE estimates of 10-year CV disease risk rely so heavily on age, sex, and race, use of these estimates to identify candidates for statins results in significant skewing of the population recommended for statins," write Navar and Peterson in their JAMA editorial.

The risk enhancers in the ACC/AHA-multispecialty guidelines, about a dozen of them, compensate for that limitation to some extent. But the PCE-dominated USPSTF risk estimates will likely miss some groups that could potentially benefit from statin therapy, Peterson agreed in an interview.  

For example, younger adults facing years of high LDL-cholesterol levels could easily have PCE-based 10-year risk below 10%. "Having a high LDL over a lifetime puts you at really high risk," he said. "Young people are missed even though their longitudinal risk is high." So, by waiting for the lofty 10% level of risk over 10 years, "we limit the use of medicine that's pretty cheap and highly effective."

Dose Intensity, Adverse Events

Also at variance from the ACC/AHA-multispecialty guidelines, the USPSTF states that, "Based on available evidence, use of moderate-intensity statin therapy seems reasonable for the primary prevention of CV disease in most persons."  

The task force specifically explored whether evidence supports some use of high-intensity vs moderate-intensity statins, Tufts University's Wong said. "We found only one study that looked at that particular question, and it didn't give us a strong answer." An elevated rosuvastatin-related diabetes risk was apparent in the JUPITER trial, "but for the other studies, we did not find that association."  

Most of the studies that explored statins for reducing risk for a first stroke or myocardial infarction used a moderate-dose statin, Wong said. "So that's what we would usually recommend."

But, Virani writes, consistent with the ACC/AHA-multispecialty guidelines, "clinicians should consider titrating the intensity of therapy to the risk of the individual." Persons in certain high-risk primary prevention groups, such as those with end-organ injury from diabetes or LDL cholesterol at least 190 mg/dL, "may derive further benefit from the use of high-intensity statin therapy."

Low-intensity statins are another potential option, but "in contrast with its 2016 recommendations, the USPSTF no longer recommends use of low-intensity statins in certain situations," observes a fourth editorial published the same day in JAMA Internal Medicine, with lead author Anand R. Habib, MD, MPhil, and senior author Rita F. Redberg, MD, MSc, both of the University of California San Francisco. Redberg is the journal's editor and has long expressed cautions about statin safety.

"While it is understandable that the Task Force was limited by lack of data on dosing, this change is unfortunate for patients because the frequency of adverse effects increases as the statin dose increases," the editorial states. Although USPSTF did not find statistically significant harm from the drugs, "in clinical practice, adverse events are commonly reported with use of statins."

It continues: "At present, there are further reasons to curb our enthusiasm about the use of statins for primary prevention of CV disease." To illustrate, the editorial questioned primary-prevention statins' balance of risk vs clinically meaningful benefit, not benefit that is merely statistically significant.

"The purported benefits of statins in terms of relative risk reduction are fairly constant across baseline lipid levels and cardiovascular risk score categories for primary prevention," the editorial states.

"Therefore, the absolute benefit for those in lower-risk categories is likely small given that their baseline absolute risk is low, while the chance of adverse effects is constant across risk categories."

However, USPSTF states, "In pooled analyses of trial data, statin therapy was not associated with increased risk of study withdrawal due to adverse events or serious adverse events." Nor did it find significant associations with cancers, liver enzyme abnormalities, or diabetes, including new-onset diabetes.

And, the USPSTF adds, "Evidence on the association between statins and renal or cognitive harms is very limited but does not indicate increased risk."

USPSTF is supported by the US Agency for Healthcare Research and Quality. "All members of the USPSTF receive travel reimbursement and an honorarium for participating in USPSTF meetings," the document states. Individual task-force disclosures can be found here.

Virani discloses receiving grants from the Department of Veterans Affairs, National Institutes of Health, and the World Heart Federation; and personal fees from the American College of Cardiology. Peterson discloses serving on the JAMA editorial board and receiving research support to his institution from Amgen, Bristol-Myers Squibb, Esperion, and Janssen; and consulting fees from Novo Nordisk, Bayer, and Novartis.

Navar discloses receiving research support to her institution from Amgen, Bristol-Myers Squibb, Esperion, and Janssen; and receiving honoraria and consulting fees from AstraZeneca, Boehringer Ingelheim, Bayer, Janssen, Lilly, Novo Nordisk, Novartis, New Amsterdam, and Pfizer.

Stone discloses receiving an honorarium from Knowledge to Practice, an educational company not associated with the pharmaceutical industry; disclosures for the other authors are in the report.

Redberg discloses receiving research funding from the Arnold Ventures Foundation and the Greenwall Foundation; disclosures for the other authors are in the report.

JAMA. Published online August 23, 2022. Recommendation Statement, Evidence Report, Editorial
JAMA Cardiol. Published online August 23, 2022.  Editorial
JAMA Netw Open. Published online August 23, 2022. Editorial
JAMA Intern Med. Published online August 23, 2022. Editorial

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