The U.S. Preventive Services Task Force (USPSTF) issued a recommendation on use of statins for primary prevention, focusing on adults ages 40 and older with no history, signs, or symptoms of cardiovascular disease (CVD). The statement updated the USPSTF's 2008 recommendation on screening for lipid disorders in adults and was based on a systematic review assessing benefits and harms of screening and treating this patient population.
The recommendations were published in JAMA on Nov. 15, 2016, and summarized in the Nov. 22, 2016, ACP Internist Weekly. The following commentary by Neha J. Pagidipati, MD, MPH, and Christopher B. Granger, MD, was published in the ACP Journal Club section of the March 21 Annals of Internal Medicine.
The USPSTF recommendations for statins for primary prevention are similar to the 2013 American College of Cardiology/American Heart Association (ACC/AHA) cholesterol treatment guidelines, with modest differences. The ACC/AHA set a treatment threshold at 10-year atherosclerotic CVD risk of 7.5%, whereas the USPSTF recommends that persons with ≥1 CVD risk factor (hypertension, smoking, diabetes, or elevated cholesterol) and a 10-year CVD risk ≥10% should receive statin therapy, with selective offering to those with a CVD risk of 7.5% to 10%.
These recommendations are based on a high-quality systematic review of a large body of evidence from major randomized trials, including the recent HOPE-3 trial. The primary prevention trials reviewed showed benefits with statins in patients with ≥1 risk factor, although none enrolled patients based solely on 10-year CVD risk score. Thus, these new recommendations may be more aligned with existing evidence. The absolute benefit of statins, reflected in the number needed to treat, is clear but modest (at least over a 3-year period), but the risk for adverse events is low. Because the ACC/AHA CVD risk score relies heavily on age, the higher 10% threshold will exclude some younger people despite multiple cardiac risk factors, including diabetes, who have a high lifetime CVD risk.
How should clinicians use the various guidelines? Both the ACC/AHA and the USPSTF recommend treating patients at moderate or high risk for CVD with statins, regardless of cholesterol levels. The availability of generic statins with lower cost has shifted the balance of cost and benefit to favor treating patients at lower thresholds of risk. The decision whether to use statins should be part of a broader strategy of risk factor management. Future studies should directly evaluate various risk-based approaches while considering risks and benefits in older adults and long-term effects in younger adults. In the meantime, clinicians should continue to prescribe statin therapy for primary prevention for patients at high or moderate risk for CVD and to have informed discussions with those at lower risk (10-year risk 5% to 10%), who may benefit from statin therapy in the long term.