Study Examines Cost-Effectiveness and Accuracy of New Cholesterol Guidelines

The 2013 ACC/American Heart Association cholesterol treatment guidelines are associated with greater accuracy and efficiency in identifying increased risk of incident cardiovascular disease events and presence of subclinical coronary artery disease, particularly in those at intermediate risk, according to a study published July 14 in JAMA. A separate study, also published in JAMA, verified that the current 10-year atherosclerotic cardiovascular disease (ASCVD) risk threshold within the guidelines accomplished these goals with an acceptable cost-effectiveness.

In a longitudinal community-based cohort study on Guideline-Based Statin Eligibility, Coronary Artery Calcification and Cardiovascular Events, researchers observed participants drawn from the offspring and third-generation cohorts of the Framingham Heart Study. Participants underwent multi-detector computed tomography for coronary artery calcification (CAC) between 2002 and 2005, and were followed up for a median 9.4 years for incident cardiovascular disease.

Results found that of the 2,345 statin-naïve participants, 39 percent were statin eligible under the ACC/AHA guidelines’ statin eligibility criteria compared with 14 percent under the ATP III guidelines. Participants who were statin eligible according to ACC/AHA guidelines also had increased hazard ratios for incident cardiovascular disease (6.8), compared to ATP III (3.1). Newly statin-eligible patients had an incident cardiovascular disease rate of 5.7 percent. Researchers also noted that participants with CAC were more likely to be stain eligible by ACC/AHA guidelines than by ATP III. “In this community-based primary prevention cohort, we demonstrate the risk of incident CVD among statin-eligible vs. noneligible participants is significantly higher when applying the ACC/AHA guidelines’ statin eligibility criteria compared with the ATP III guidelines,” the study authors write. “This finding is consistent across subgroups and particularly important in participants at CVD risk.”

In the separate study looking at the cost-effectiveness of 10-year risk thresholds for the initiation of statin therapy, researchers used a microsimulation model in which hypothetical individuals from a representative U.S. population, ranging in from 40 to 75 years of age, received statin treatment, experienced ASCVD events and died from ACSVD-related or non-ASCVD-related causes based on ASCVD natural history and statin treatment parameters. The analysis found that the resulting health benefits of the 10-year risk threshold of 7.5 percent+ currently used in the ACC/AHA guidelines were worth the additional costs required in their achievement (with an incremental cost-effectiveness ration lower than the conservative $50,000/quality-adjusted life-year threshold). The research also suggests that more lenient ASCVD risk thresholds of 3.0 percent to 4.0 percent+ represented cost-effective options. In addition to cost-effectiveness, a projected shift from the 7.5 percent threshold to 3.0 percent to 4.0 percent+ was associated with an estimated additional 125,000 to 160,000 cardiovascular disease events averted. 

Moving forward, the study authors suggest that future research should consider a risk-benefit analysis focused on costs and potential adverse effects of statins, especially in patients with pre-diabetes and in lower-risk patients, in order to provide a complete assessment of the effects of the change in statin eligibility guidelines on the healthcare system. Additionally, researchers and physicians should continue to analyze the cost-effectiveness versus the number of ASCVD events prevented within varying thresholds in order to further the success of existing guidelines.

“Based on available evidence, including the two reports in this issue of JAMA, answers to the questions of in whom and how regarding cholesterol lowering are now more clear than they were just 18 months ago,” writes Philip Greenland, MD, of the Northwestern University Feinberg School of Medicine, Chicago, and Senior Editor, JAMA, and Michael S. Lauer, MD, of the National Heart, Lung, and Blood Institute. “There is no longer any question as to whether to offer treatment with statins for patients for primary prevention, and there should now be fewer questions about how to treat and in whom. 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.”

Clinical Topics: Dyslipidemia, Noninvasive Imaging, Prevention, Atherosclerotic Disease (CAD/PAD), Lipid Metabolism, Nonstatins, Novel Agents, Statins

Keywords: Adenosine Triphosphate, American Heart Association, Atherosclerosis, Cholesterol, Cohort Studies, Coloring Agents, Coronary Artery Disease, Coronary Disease, Diabetes Mellitus, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Longitudinal Studies, National Heart, Lung, and Blood Institute (U.S.), Primary Prevention, Tomography

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