Ford ES, Will JC, Mercado CI, Loustalot F. Trends in Predicted Risk for Atherosclerotic Cardiovascular Disease Using the Pooled Cohort Risk Equations Among US Adults From 1999 to 2012. JAMA Intern Med. 2015;175(2):299-302. doi:10.1001/jamainternmed.2014.6403
Risk assessment has become an important tool to assess an individual’s future risk for cardiovascular disease. Recently, the American College of Cardiology/American Heart Association (ACC/AHA) released a report that presented updated risk equations, the Pooled Cohort Risk Equations, for cardiovascular disease.1 Race and ethnicity-specific estimates were novel to the new risk equations. Because changes over time in predicted cardiovascular risk using these new risk equations have not been examined, our objectives were to (1) examine the trend in predicted 10-year cardiovascular risk using the new ACC/AHA Pooled Cohort Risk Equations and (2) estimate the potential for risk reduction by optimizing levels of cardiovascular risk factors.
We used data from seven 2-year cycles of the National Health and Nutrition Examination Survey (1999-2000 to 2011-2012) that includes nationally representative samples of the US population selected with a complex multistage sampling design.2 Response rates for the interview and examination stages all exceeded 70%. The surveys were approved by the National Center for Health Statistics Research Ethics Review Board.
We used the Pooled Cohort Risk Equations to calculate predicted 10-year cardiovascular risk1 and limited the analyses to men and nonpregnant women who were aged 40 to 79 years and free of self-reported congestive heart failure, coronary heart disease, angina, myocardial infarction, or stroke. Tests for trend were calculated by using orthogonal linear contrasts. Racial- or ethnic-specific estimates were limited to the 3 major racial or ethnic groups (ie, Mexican American, non-Hispanic white, and non-Hispanic black). To account for the complex sampling design of the surveys, we conducted the analyses with SUDAAN statistical software (RTI International).
Of the 5 modifiable cardiovascular risk factors, significant improvements occurred for total cholesterol, high-density lipoprotein cholesterol, systolic blood pressure, and smoking status (Table 1). The prevalence of diabetes increased progressively.
Overall, risk of 20% or greater declined from 13.0% to 9.4% (P value for trend, .008). Risk of 20% or greater decreased significantly among women (P value for trend, <.001), non-Hispanic whites (P value for trend, .02), non-Hispanic white women (P value for trend, .001), and non-Hispanic black women (P value for trend, .03). During each 2-year cycle, predicted 10-year cardiovascular risk of 20% or greater was higher among men compared with women and among non-Hispanic black women compared with non-Hispanic white women.
Using data from 2011-2012, we examined the potential impact of aligning modifiable risk factors levels with optimal values on predicted 10-year cardiovascular risk. The reduction of systolic blood pressure to lower than 120 mm Hg yielded the largest drop in mean predicted risk, followed by the elimination of diabetes, and elimination of smoking (Table 2). When all 5 cardiovascular risk factors were simultaneously optimized, mean predicted risk declined by 3.3% overall, 6.4% among non-Hispanic black men, and 4.5% among non-Hispanic black women.
Our results show that predicted 10-year cardiovascular risk among women has improved substantially compared with men; predicted risk was higher among non-Hispanic black women than among non-Hispanic white and Mexican American women; and predicted risk lower than 7.5% declined significantly among non-Hispanic black men. Also, improvements in risk factors levels, led by systolic blood pressure, can produce substantial reductions in future cardiovascular disease. Interventions aimed at improving the modifiable risk factors other than total cholesterol level could help to narrow the gender gap in predicted risk, and improving systolic blood pressure and concentrations of hemoglobin A1c could help to narrow the racial disparity.
The limited evidence about the validity of the Pooled Cohort Risk Equations poses one limitation.3 Furthermore, we were unable to exclude participants who underwent cardiovascular procedures such as percutaneous coronary interventions.
Sex and racial disparities in cardiovascular risk continue to exist, and the risk factors fueling these disparities will require redress. The enormous progress in reducing cardiovascular disease mortality realized since the 1960s represent public health and health care improvement successes, yet more progress in reducing the remaining colossal burden of cardiovascular disease in the United States awaits.
Corresponding Author: Earl S. Ford, MD, MPH, Centers for Disease Control and Prevention, 4770 Buford Hwy, MS F78, Atlanta, GA 30341 (firstname.lastname@example.org).
Published Online: December 8, 2014. doi:10.1001/jamainternmed.2014.6403.
Author Contributions: Dr Ford had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Ford, Will.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: Ford.
Critical revision of the manuscript for important intellectual content: Will, Mercado, Loustalot.
Statistical analysis: Ford, Will.
Administrative, technical, or material support: Loustalot.
Study supervision: Ford.
Conflict of Interest Disclosures: None reported.
Disclaimer: The findings and conclusions in this article are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.