We Believe in PREVENTing Overestimation of Cardiovascular Risk

EBM Focus - Volume 18, Issue 39

Reference: Circulation. 2023 Nov 10 early online

Practice Point: AHA PREVENT, a new cardiac risk calculator, does a better job at estimating risk than those prior. Notable changes are the removal of race, wider age applicability, and the addition of eGFR and optional hemoglobin A1C, urine albumin-to-creatinine ratio, and social deprivation index.

EBM Pearl: Validation studies for risk calculators should include assessments of discrimination and calibration to themselves be valid.

The American Heart Association (AHA) recently unveiled a new race-free calculator that was shown to predict cardiac risk more accurately than the Pooled Cohort Equations (PCEs) introduced by the AHA/ACC in 2013 (commonly known as the ASCVD calculator). It is well-known that the PCEs overestimate risk; for example, they overestimated risk by 86% in men and 67% in women in an independent validation cohort study published in Annals in 2015. The PCEs also perpetuate the use of race, a social construct, as a medically valid classifier, contributing to systemic racism and health inequities. So, a new and better option than the PCEs really is a gift to one and all this holiday season!

In addition to standard markers of cardiovascular risk such as age, sex, blood pressure, cholesterol, and smoking status, the Predicting Risk of cardiovascular disease EVENTs (PREVENT) Equations add eGFR as a predictor in addition to optional measures of kidney function (urine albumin-to-creatinine ratio), metabolic risk (hemoglobin A1c), and social determinants of health (social deprivation index). They can be applied to adults 30-79, which is a wider age range than the PCEs, and they predict both 10- and 30-year risk of ASCVD and heart failure (together and separately). Estimating 30-year risk (which is essentially lifetime risk for some) is tricky, however, so there is still potential for overestimation over that longer time frame.

The rationale and clinical implications of the PREVENT Equations are discussed in an AHA Scientific Statement recently published in Circulation. In it, the AHA confidently concludes that the PREVENT Equations do a better job of predicting risk than the PCEs. But if you were one of those kids asking scientific questions about Santa as soon as you could talk, you might be one of those adults who needs to see the actual validation studies before you believe something like this. We definitely did. It took a bit of digging, but we found it - an early-release, accepted (i.e. peer-reviewed) manuscript that contains critical data about how well the PREVENT Equations perform in appropriate validation cohorts (the reference study for this Focus). A little heads up, though: if you’ve never heard of “discrimination” and “calibration”, you might want to skip trying to read the full text and just trust us when we say we’ve reviewed the evidence and it made believers out of us.

If you’re curious (or weren’t really that curious before and are now annoyed that you started reading this line and can’t stop because now you are), discrimination involves correctly separating people into risk strata (e.g., low, medium, high), while calibration reflects the accuracy of the numeric risk assigned to people within the risk strata. For example, you could have a risk tool that stratifies two people as “low” and “moderate” risk correctly (good discrimination), but if the risk assigned to “low” is 1% and “moderate” is 7% but their actual risks are 6% and 13% respectively, the calibration is bad.

To wrap this up with a nice red bow, the new AHA PREVENT Equations combine measures of cardiovascular, metabolic, and renal health along with social factors to estimate cardiac risk - both ASCVD and heart failure. PREVENT can be used for people aged 30-79 and offers both 10- and 30-year risk estimates. By our account, PREVENT seems to outperform the PCEs and is likely to replace the PCEs altogether. The PREVENT Equations are not available for use yet, although our very own DynaMed Decisions is working diligently and swiftly to unveil this tool for your use very soon - maybe even before the AHA does. Cheers!

For more information, see the topic Cardiovascular Risk Assessment in DynaMed.

DynaMed EBM Focus Editorial Team

This EBM Focus was written by Katharine DeGeorge, MD, MS, Senior Deputy Editor at DynaMed and Associate Professor of Family Medicine at the University of Virginia. Edited by Alan Ehrlich, MD, Executive Editor at DynaMed and Associate Professor in Family Medicine at the University of Massachusetts Medical School; Dan Randall, MD, Deputy Editor at DynaMed; Nicole Jensen, MD, Family Physician at WholeHealth Medical; Vincent Lemaitre, PhD, Medical Editor at DynaMed; Elham Razmpoosh, PhD, Postdoctoral fellow at McMaster University; Hannah Ekeh, MA, Senior Associate Editor at DynaMed; and Jennifer Wallace, BA, Associate Editor at DynaMed.