Questions about how to prescribe statins for primary prevention abound more than 3 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.
The document, little changed from the draft guidance released for public comment in February, was published online Aug. 23 in JAMA and the USPSTF website.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, American Heart Association, 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 one of only four 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, told this news organization.
“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 Dr. 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, 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, Dr. 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, said in an interview.
“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,” Dr. 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,” Dr. 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.