John T. Wilkins
Evidence is currently insufficient regarding the benefits and harms of adding ankle-brachial index, high-sensitivity C-reactive protein or coronary artery calcification score to traditional risk assessment for CVD in patients who are asymptomatic, according to a recommendation statement released by the U.S. Preventive Services Task Force and published in JAMA.
This recommendation statement is an update to the 2009 USPSTF recommendation to assess CHD risk with nontraditional risk factors.
“The major change in the current recommendation is that the USPSTF evaluated the Pooled Cohort Equation in addition to the Framingham Risk Score and focused on only three nontraditional risk factors — the [ankle-brachial index], [high-sensitivity] CRP level, and CAC score,” the task force wrote.
Risk assessment models
Pooled Cohort Equation, the Framingham Risk Score or similar CVD risk assessment models are used to determine the best treatment to prevent CVD events in patients, although additional risk factors may improve how to target treatments, thereby maximizing benefits while minimizing harms, according to the recommendation statement, according to the statement.
There is adequate evidence that adding high-sensitivity CRP level, ankle-brachial index or CAC score in existing CVD risk assessment models may improve discrimination, calibration and reclassification.
Despite this, there is inadequate evidence regarding the benefit of adding high-sensitivity CRP level, ankle-brachial index or CAC score to risk assessment models and their ability to reduce the incidence of CVD events and mortality. Adequate evidence is also available on the harms of risk assessment and intervention, showing that the risk for harms is small. Harms include inappropriate risk reclassification, abnormal test results, anxiety and incidental findings.
“The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of adding the [ankle-brachial index], [high-sensitivity] CRP level or CAC score to traditional risk assessment for CVD in asymptomatic adults to prevent CVD events,” the task force wrote.
Based on available evidence, the task force recommends the use of Pooled Cohort Equation to assess CVD risk and to guide treatment decisions for patients who are asymptomatic and do not have a history of CVD, as it can reduce the incidence of potential harms and preventable burden.
Donald M. Lloyd-Jones
Correctly identifying a patient who has a high risk for stroke, nonfatal MI and CVD can allow health care providers to implement more intensive risk factor management to reduce this risk, according to the recommendation statement.
Although Pooled Cohort Equation and the Framingham Risk Score are commonly used, they have been shown to overestimate and underestimate risk in some patients.
“Identification of additional tests (for nontraditional risk factors) that could improve risk prediction, including the [ankle-brachial index], [high-sensitivity] CRP level and CAC score, is of interest,” the task force wrote.
Many studies have shown the link between high-sensitivity CRP level, ankle-brachial index or CAC score and CV outcomes, although more studies are needed to compare traditional risk assessment alone with traditional risk factors plus high-sensitivity CRP level, ankle-brachial index or CAC score. Other research that is necessary in this area include those with more diverse populations and those reflective of real-world practice.
“These USPSTF recommendations should spur ascertainment of the data needed to turn I statements into more definitive recommendations, specifically regarding the use of CAC measurement,” John T. Wilkins, MD, MS, assistant professor of medicine (cardiology)/preventive medicine at Northwestern University Feinberg School of Medicine, and Donald M. Lloyd-Jones, MD, ScM, senior associate dean for clinical and translational research, chair of the department of preventive medicine, director of Northwestern University Clinical and Translational Sciences Institute, Eileen M. Foell Professor and professor of preventive medicine (epidemiology) and medicine (cardiology) at Northwestern University Feinberg School of Medicine, wrote in a related editorial. “If CAC measurement succeeds in an endpoints-driven clinical trial, it will be unnecessary to fund research developing weaker biomarkers. If CAC measurement were to fail as a useful biomarker for CVD risk in an adequately powered trial, it certainly would not be necessary to develop weaker biomarkers, but rather, the current approach to primary prevention of CVD would need to be fundamentally reconsidered.” – by Darlene Dobkowski
Disclosures: The task force members, Wilkins and Lloyd-Jones report no relevant financial disclosures.