Coronary Artery Calcium Score Helps Identify Patients Who Would Benefit from Statins

A recent study has examined the accuracy of the US Preventive Services Task Force (USPSTF) and American College of Cardiology/American Heart Association (ACC/AHA) recommendations for identifying African American individuals who would benefit from statins.

The ACC/AHA guidelines recommend statin treatment to a greater proportion of African Americans compared with the USPSTF, but the ACC/AHA’s wider approach may also lead to overtreatment. In comparison, the USPSTF’s guidelines are more narrowly focused on a subset of patients at a higher risk, but the selectivity of these guidelines increases the potential to miss individuals who should be treated.

Researchers of the study, published in JAMA Cardiology, evaluated 2812 African American individuals aged 40-75 years old without prevalent atherosclerotic cardiovascular disease (ASCVD). Patients underwent an assessment of cardiovascular risk, measured by nonzero coronary artery calcium (CAC) score, abdominal aortic calcium score, and incident ACVD (myocardial infarction, ischemic stroke, or fatal coronary disease).

The USPSTF guidelines captured 55.2% of American Americans with a CAC score above 0, and the ACC/AHA captured 69.3%.

Statin recommendation under both guidelines was associated with a CAC score greater than 0. Individuals who were eligible for statins according to both guidelines also experienced 9.6 cardiovascular events per 1000 patient-years, but those indicated by ACC/AHA guidelines were at a low to intermediate risk. The 10-year ASCVD incidence per 1000 person-years was 8.1 in the presence of CAC and 3.1 without CAC for statin-eligible patients under ACC/AHA guidelines.

Statin-eligible participants by USPSTF guidelines did not have a significantly higher 10-year ASCVD event rate in the presence of CAC, but those who were not eligible had a higher ASCVD event rate in the presence of CAC relative to without CAC.

The USPSTF guidelines targeted 38% of high-risk African American individuals for statin therapy, but did not recommend treatment in nearly 25% of individuals who were eligible for statins by ACC/AHA guidelines and who had a low to intermediate ASCVD risk.

The researchers determined that the addition of CAC scoring improved risk stratification above guideline recommendations, in which participants eligible for statins under ACC/AHA guidelines with CAC were at a higher risk than those without CAC.

The study also found that participants with CAC who were not recommended statins under USPSTF guidelines experienced higher cardiovascular event rates than those without CAC. These findings indicate a potential for the addition of CAC to more accurately identify African American individuals who need statins and personalize recommendations for statin therapy based on both guideline recommendations.

Reference

Shah RV, Spahillari A, Mwasongwe S, et al. Subclinical atherosclerosis, statin eligibility, and outcomes in African American individuals. Jama Cardiol. Published online March 18, 2017. doi:10.1001/jamacardio.2017.0944