Revised Pooled Cohort Equations for Estimating ASCVD Risk

Study Questions:

Can the clinical accuracy of cardiovascular disease (CVD) risk prediction using the American College of Cardiology/American Heart Association 2013 pooled cohort equations (PCEs) be improved using newer data and statistical methods?

Methods:

Background: The 2013 PCEs for predicting 10-year atherosclerotic CVD (ASCVD) risk have been criticized for overestimating risk, which may in part be explained by use of “old data,” particularly the Framingham Heart Study (FHS), which included men and women aged 32-62 years in 1948.

Revisions: The authors derived and validated novel CVD risk equations using 26,689 adults aged 40-79 years without CVD from six US cohort studies designed to assess CVD risk in specific populations (ARIC [Atherosclerosis Risk in Communities] in middle-aged adults from four US communities, 1987-2011; CHS [Cardiovascular Health Study] in the elderly, defined as age >65 years, 1989-1999; CARDIA [Coronary Artery Risk Development in Young Adults] study, 1983-2006; FHS offspring spouse pairs, 1971-2014; JHS [Jackson Heart Study] in African Americans, 2000-2012; and MESA [Multi-Ethnic Study of Atherosclerosis], four ethnic groups in six US cities, 2000-2012). CVD was defined with outcome variables as in PCEs including nonfatal myocardial infarction (MI), death from coronary heart disease, or fatal or nonfatal stroke. The study was limited to men and women aged 40-79 years, and white or black race, with no history of coronary artery disease, stroke, congestive heart failure, or atrial fibrillation.

Results:

The 2013 PCEs overestimated 10-year risk for ASCVD by an average of 20% across risk groups including <5% to 10% or greater. Misestimation of risk was particularly prominent among black adults, of whom 3.9 million (33% of eligible black persons) had extreme risk estimates (<70% or >250% of those of white adults with otherwise-identical risk factor values). Updating these equations improved accuracy among all race and sex subgroups. Approximately 11.8 million US adults previously labeled high-risk (10-year risk ≥7.5%) by the 2013 PCEs would be relabeled lower-risk by the updated equations. Updating the 2013 PCEs with data from modern cohorts reduced the number of persons considered to be at high risk.

Conclusions:

Revised PCEs can improve the accuracy of CVD risk estimates. The findings also indicate that risk equations will generally become outdated over time and require routine updating. Clinicians and patients should consider the potential benefits and harms of reducing the number of persons recommended aspirin, blood pressure, or statin therapy.

Perspective:

The ‘revised PCEs’ reduce overestimation of need for statins among modern populations and particularly extreme estimates for black adults. They also reduce the use of aspirin for ‘primary prevention’ and drug therapy for hypertension (10-year risk of 10% or greater), as suggested in recent guidelines. Importantly, it was not sufficient to correct misestimation problems; the statistical methods also required revision to improve equation accuracy.

Clinical Topics: Congenital Heart Disease and Pediatric Cardiology, Dyslipidemia, Geriatric Cardiology, Prevention, Atherosclerotic Disease (CAD/PAD), CHD and Pediatrics and Arrhythmias, CHD and Pediatrics and Prevention, CHD and Pediatrics and Quality Improvement, Nonstatins, Novel Agents, Statins, Hypertension

Keywords: African Americans, Aspirin, Atherosclerosis, Blood Pressure, Coronary Artery Disease, Ethnic Groups, Geriatrics, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Hypertension, Myocardial Infarction, Primary Prevention, Risk Assessment, Stroke, Vascular Diseases, Young Adult


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