The Bottom Line: Major guidelines recommend that decisions about aspirin, blood pressure, and statin treatments be informed by 10-year CVD risk estimates from the PCEs, which were derived in 2013 using data from 5 cohort studies. These PCEs are controversial because of reports that they substantially misestimate risk. Two basic strategies to revise the PCEs could improve their accuracy: updating the data from which they are derived and changing the statistical methods used to derive them (Yadlowsky et al, 2018).
In his review of the recent study by Yadlowsky et al (2018), Dr. Dan Dressler provides the following example: Assume the patient is a 68-year-old white man with the following favorable risk profile: Total cholesterol, 160 mg/dL; HDL cholesterol, 55 mg/dL; blood pressure, 120/70 mm Hg; and no history of diabetes, hypertension, or smoking. His 10-year CVD risk is 12% on the ACC/AHA calculator, but only 6% on this new model’s calculator. The latter risk is below the threshold at which most clinicians would recommend statin therapy (Dressler, 2018).
References: Dressler DD. 10-year cardiovascular risk might be lower than we thought. NEJM Journal Watch. 2018 Jun 21.
Yadlowsky S, Hayward RA, Sussman JB, McClelland RL, et al. Clinical implications of revised pooled cohort equations for estimating atherosclerotic cardiovascular disease risk. Ann Intern Med. 2018 Jun 5. doi:10.7326/M17-3011
Summary: The clinical implications of the results suggest that the revised PCEs will reduce overestimation of risk in general and may prevent adverse events, health care costs, and inflated expectations of absolute risk and corresponding absolute therapeutic benefit. Additionally, use of the updated equations will correct erroneous, implausible risk estimates for many African American adults (Yadlowsky et al, 2018).
The study by Yadlowskey et al (2018) validates what some clinicians have observed in practice: Some patients are classified inaccurately as “high risk.” Although guidelines that depend on risk calculation would not necessarily need to change if risk calculators are updated, the number of patients who would be affected by guideline recommendations could be lowered dramatically (Dressler 2018).