Headed in the Right Direction But at Risk for Miscalculation

Abstract

The newly released 2013 ACC/AHA Guidelines for Assessing Cardiovascular Risk makes progress compared with previous cardiovascular risk assessment algorithms. For example, the new focus on total atherosclerotic cardiovascular diseases (ASCVD) is now inclusive of stroke in addition to hard coronary events, and there are now separate equations to facilitate estimation of risk in non-Hispanic white and black individuals and separate equations for women. Physicians may now estimate lifetime risk in addition to 10-year risk. Despite this progress, the new risk equations do not appear to lead to significantly better discrimination than older models. Because the exact same risk factors are incorporated, using the new risk estimators may lead to inaccurate assessment of atherosclerotic cardiovascular risk in special groups such as younger individuals with unique ASCVD risk factors. In general, there appears to be an overestimation of risk when applied to modern populations with greater use of preventive therapy, although the magnitude of overestimation remains unclear. Because absolute risk estimates are directly used for treatment decisions in the new cholesterol guidelines, these issues could result in overuse of pharmacologic management. The guidelines could provide clearer direction on which individuals would benefit from additional testing, such as coronary calcium scores, for more personalized preventive therapies. We applaud the advances of these new guidelines, and we aim to critically appraise the applicability of the risk assessment tools so that future iterations of the estimators can be improved to more accurately assess risk in individual patients.

Accuracy of the Atherosclerotic Cardiovascular Risk Equation in a Large Contemporary, Multiethnic Population

“…In sum, as recently recommended (27), we conducted a critical evaluation of the ASCVD Pooled Cohort risk equation from a relevant large, diverse, “real-world” target population, overall and in key understudied subgroups. We found that this risk equation substantially overestimated actual ASCVD risk in adults not treated with statin therapy for primary prevention without diabetes (overall and across all sociodemographic subgroups), and demonstrated suboptimal accuracy in those with or without diabetes.…”

Pathways Forward in Cardiovascular Disease Prevention One and a Half Years After Publication of the 2013 ACC/AHA Cardiovascular Disease Prevention Guidelines

“…19 Differences in socioeconomic status and secular trends of CVD risk factors not captured in risk scores, along with changing incidence patterns of CVD and overall health between the cohorts used for developing the Pooled Cohort Equations and modern populations, may explain this phenomenon. 6 Further research in this area will enhance our understanding regarding the reasons for such overestimation.…”

Providing Evidence for Subclinical CVD in Risk Assessment

“…In 2011, DeFilippis et al demonstrated a 40% higher risk of incident CAC per 5% higher absolute FRS risk, and a mean 7 Agatston score increase per 5% higher FRS among those with existing CAC. 15 However given concerns about possible limitations of the FRS, 16 including lack of race and ethnic diversity in the derivation sample and the absence of certain newly identified risk factors, competing risk scores including the Reynolds Risk Score (RRS) were also studied. The 2008 RRS added family history and high sensitivity C-reactive protein (hsCRP) to the risk algorithm along with the traditional Framingham risk factors.…”