Who Should Get a Statin? Guidelines Don’t Match Up

Fewer patients would be prescribed statin therapy if physicians based treatment decisions on the United States Preventive Services Task Force (USPSTF) guidelines for primary prevention of cardiovascular disease than if they followed the American College of Cardiology/American Heart Association (ACC/AHA) guidelines, a new analysis shows.

In a study published April 18, 2017, in JAMA, researchers estimate that 15.8% of US adults aged 40 to 75 years without cardiovascular disease would be eligible for statin therapy with the USPSTF guidelines compared with 24.3% of participants according to the ACC/AHA recommendations.

This would translate into an additional 9 million Americans treated with statins if the ACC/AHA recommendations were followed as opposed to those of the USPSTF.

Speaking with TCTMD, lead investigator Neha Pagidipati, MD (Duke Clinical Research Institute, Durham, NC), pointed to the shift from the LDL-target-based approach used in earlier cholesterol guidelines to an approach focused on treatment according to atherosclerotic cardiovascular disease (ASCVD) risk, which forms the basis of the 2013 ACC/AHA recommendations.

“There was a lot of controversy around this, because it was such a paradigm shift,” she said. “One of the issues was that it would lead to an enormous increase in the number of people who would be eligible for primary prevention statin therapy in the US. Another is that is that it’s based on the ASCVD risk calculator, which had not been validated prospectively and may have issues with overestimating risk in certain populations.”

In this context, the USPSTF published their own clinical recommendations in 2016 on the use of statins for primary prevention. The ACC/AHA and USPSTF guidelines are quite similar, although the USPSTF recommends a higher risk threshold for initiating statin therapy. The USPSTF recommends low-to-moderate-dose statin therapy in adults 40 to 75 years old without a history of cardiovascular disease who have at least one cardiovascular risk factor and a 10-year event risk of 10% or greater. The ACC/AHA recommends moderate-intensity statin therapy in patients with a 10-year ASCVD risk of 7.5% or greater (and LDL cholesterol ≥ 70 mg/dL).

In this new analysis, which is based on data from 3,416 participants in the 2009-2014 National Health and Nutrition Examination Survey (NHANES), including 747 individuals currently taking lipid-lowering therapy, the ACC/AHA and USPSTF guidelines yielded the same recommendation in 36.9% of patients. In 53.8% of the study population, the ACC/AHA and USPSTF guidelines were concordant in recommending no treatment.

For the 8.9% of participants who would be recommended statin therapy based on the ACC/AHA guidelines but not the USPSTF, Pagidipati explained that 28% had diabetes and 55% were younger (aged 40 to 59 years).

“Even though they had a modest 10-year risk of developing heart disease or stroke, they’re actually at very high long-term risk,” she said. “Over the 30-year horizon, one in three of them are projected to develop atherosclerotic cardiovascular disease. If we only look at the shorter term, we don’t actually see that high a risk.”

Two Guidelines a Reflection of Controversy

For Pagidipati, the existence of two sets of guidelines is indicative of the controversy surrounding statin use in the setting of primary prevention. “It can be confusing to physicians who are trying to decide what to do for their patients and for patients trying to determine what the right decision is for them,” she said.

Regardless of the recommendations, both the ACC/AHA and USPSTF emphasize the importance of having a conversation. “An informed discussion with the provider and patient is absolutely essential when making decisions about statin therapy, and the decision should be made within the context of overall lifestyle management goals,” said Pagidipati.

Same wine, different bottle. Khurram Nasir

Khurram Nasir, MD (Baptist Health South Florida, Miami), who was not involved in the analysis, said he views the competing primary-prevention recommendations as “the same wine, different bottle.” He noted that both guidelines recommend treating patients based on the calculated risk of ASCVD, with the only real difference being the threshold differential.

“The USPSTF is slightly more conservative, but in spite of the fact that it is more conservative, if it is fully implemented there are still going to be millions more people who are candidates for statins,” Nasir told TCTMD. Like Pagidipati, he noted that a number of studies over the past few years have shown the risk-based approach for statin therapy tends to overestimate the actual risk of ASCVD, with some statin-eligible patients being at much lower risk than suggested by risk calculators.

With the ACC/AHA and USPSTF guidelines, “we’ve increased the likelihood that a lot of people who are at risk will be captured, but at the same time the unintended consequence is asking a lot of low-risk people to also to commit to statins,” said Nasir.

If a primary-prevention patient in his practice is uncertain about committing to lifelong statin therapy, he advocates coronary artery calcium (CAC) screening. Nasir noted that several studies have shown that CAC screening can stratify ASCVD risk in statin-eligible patients, with one recent study showing that CAC score of zero significantly shifts the 10-year risk of ASCVD downward.

Regarding the adoption of the 2013 ACC/AHA guidelines, a study published April 1, 2017, in JAMA Cardiology analyzed treatment trends and found that implementation of the guidelines was modest at best among 161 practices participating in the PINNACLE registry.