Cholesterol management guidelines issued by the American College of Cardiology and American Heart Association (ACC/AHA) scored high marks in a recent analysis. The results, published in the Journal of the American Medical Association (JAMA), indicated that the 2013 AHA/ACC guidelines did a better job at identifying risk of incident cardiovascular disease (CVD) than an earlier set of guidelines—particularly for individuals with intermediate CVD risk.
The ACC/AHA guidelines ushered in a new approach for treating CVD, “focusing on absolute cardiovascular risk as estimated by the 10-year atherosclerotic CVD (ASCVD) score for statin treatment,” according to the JAMA article. Under these guidelines, about 13 million additional adults would meet eligibility criteria for statins, compared with the National Cholesterol Education Program’s 2004 Updated Third Report of the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATP III) guidelines.
The two sets of criteria differ in that the ACC/AHA guidelines hone in on statin therapy instead of a number of different classes of drugs, proposing treatment for four high-risk groups. The guidelines’ inclusion of all cardiovascular diseases as a prevention target is also much broader than what ATP III guidelines propose.
Whether the ACC/AHA guidelines overestimates risk has raised some concerns. “Nearly immediately after release of the guidelines there was considerable scrutiny and controversy regarding the fourth clinical scenario: primary prevention in adults without diabetes but with an estimated 10-year ASCVD risk of 7.5% or higher,” an editorial in JAMA that discusses the study’s results explains.
To determine the proficiency of these newer guidelines in detecting adults with higher risk of CVD or coronary artery calcification (CAC), researchers did a comparative analysis of the ATP III and ACC/AHA guidelines, drawing from the data of several generations who participated in the original community-based Framingham Heart Study. The study population included 2,435 asymptomatic adults who were not taking statins.
The percentage of individuals who actually developed incident CVD during the study period varied little among the two criteria groups—6.9% who met ATP III criteria versus 6.3% who met ACC/AHA criteria. Yet, a noticeably higher percentage of participants qualified for statin treatment under the ACC/AHA criteria (39%) compared with just 14% under the 2004 ATP III criteria.
The ACC/AHA criteria were also more adept at identifying which participants at intermediate risk needed statin therapy, in addition to those who were at low risk and did not require treatment. Overall, 80% of intermediate risk participants met criteria for statin treatment under the ACC/AHA guidelines, compared with just 27% under ATP III.
Some degree of CAC was found in more than 40% of the participants. Among those at highest risk—with a CAC score of 300 or higher—85% qualified for statins under the ACC/AHA criteria, whereas just 34% qualified under the ATP III criteria.
Overall, these results show that the ACC/AHA criteria “were associated with greater accuracy and efficiency in identifying increased risk of incident CVD events and presence of subclinical coronary artery disease, particularly in those at intermediate risk,” the investigators concluded.
The study’s results should reinforce the use of statins as a first-line prevention method, while clarifying which individuals need treatment, the JAMA editorial stated. “Rather, the next phase of research should be directed at better ways of applying lifestyle and drug treatments to the millions, and possibly billions, worldwide who could potentially benefit from a cost-effective approach to primary prevention of ASCVD,” the editorial’s authors suggested.
A separate JAMA article concluded that thresholds even lower than the ACC/AHA’s 7.5% 10-year CVD risk would be optimal as a cost-effective approach for treating adults with statins.