Atherosclerosis, the buildup of plaque on the artery walls, happens slowly over time. That means it is occurring long before a person suffers a heart attack or stroke. It can be significantly reduced with the use of statins, drugs that prevent arterial plaques from forming.

Recommendations for statin therapy vary, depending on the health organization writing them, and this seems to particularly affect African Americans, according to a new study.

The addition of a coronary artery calcification score helped to further identify those at increased risk above the guideline recommendations.

Controversy still surrounds the American Heart Association/American College of Cardiology (AHA/ACC) guidelines, which were released in 2013, one of the study's authors, Venkatesh Murthy, told TheDoctor. The AHA guidelines stand in contrast to those of the U.S. Preventive Services Task Force (USPSTF) which are more conservative and hold back on statin therapy for more people.

Both sets of guidelines recommend that Americans of all races with high cholesterol be treated with statins, which, like other classes of safe and effective medications, still carry some risk of side effects. The difference is the point at which a call for statin treatment is triggered.

While there have been many studies of statins, few of them have focused solely on African Americans, despite their higher risk for cardiovascular disease. The researchers wanted to see if African Americans who could benefit from statin therapy might be slipping through the cracks as a result of the guidelines.

The team looked at data from 2,812 African American participants in the Jackson Heart Study who were at risk for ASCVD. Of these roughly 2,800 people, about 1,750 received a computed tomography (CT) scan to look at coronary artery calcification (CAC), used to evaluate the risk of stroke or heart attack.

The researchers found that the conservative USPSTF guidelines identified 404 of 732 African American participants with a coronary artery calcification score greater than 0; the AHA/ACC guidelines identified more — 507 persons. Statin therapy is recommended per both guidelines for those with a CAC score greater than 0. So about 1 in 4 persons who would be recommended for statins under the ACC/AHA guidelines would not be recommended under the USPSTF guidelines.

The researchers also found that although persons recommended for statins under both sets of guidelines had a similar risk of ASCVD compared to those who would not be recommended, the addition of a coronary artery calcification score helped to further identify those at increased risk above the guideline recommendations.

“It was interesting that adding the CAC score to the recommendations in the guidelines would help further identify those at increased risk, and it actually did for both sets of guidelines,” Aferdita Spahillari, another author of the study, told TheDoctor. “You can choose either the ACC/AHA or USPSTF philosophy, but if you choose to be more conservative, you will have a price to pay,” said Murthy, a cardiologist at the University of Michigan. Being more conservative in trying to reduce cholesterol levels may increase the number of heart attacks and strokes that are not prevented.

Patients should use these recommendations as part of the discussion with their physicians about how to treat their high cholesterol, said Spahillari, a cardiology fellow at Tufts University Medical Center and Beth Israel Deaconess Medical Center in Boston. “What our study suggests is that neither set of guidelines is perfect, and treatment should be individualized based on patient preference and what risks they are willing to take.”

Going forward, researchers definitely need better tools to identify who is at risk and who are those people who will do well on statins in the long run, said Murthy. This study is a step in that direction.

The study is published in JAMA Cardiology.