Predictive Validity of the American College of Cardiology/American Heart Association Pooled Cohort Equations in Predicting All-Cause and Cardiovascular Disease-Specific Mortality in a National Prospective Cohort Study of Adults in the United States

Abstract

The predictive validity of the Pooled Cohort risk (PCR) equations for cardiovascular disease (CVD)-specific and all-cause mortality among a national sample of US adults has yet to be evaluated, which was this study's purpose. Data from the 1999-2010 National Health and Nutrition Examination Survey were used, with participants followed up through December 31, 2011, to ascertain mortality status via the National Death Index probabilistic algorithm. The analyzed sample included 11,171 CVD-free adults (40-79 years of age). The 10-year risk of a first atherosclerotic cardiovascular disease (ASCVD) event was determined from the PCR equations. For the entire sample encompassing 849,202 person-months, we found an incidence rate of 1.00 (95% CI, 0.93-1.07) all-cause deaths per 1000 person-months and an incidence rate of 0.15 (95% CI, 0.12-0.17) CVD-specific deaths per 1000 person-months. The unweighted median follow-up duration was 72 months. For nearly all analyses (unadjusted and adjusted models with ASCVD expressed as a continuous variable as well as dichotomized at 7.5% and 20%), the ASCVD risk score was significantly associated with all-cause and CVD-specific mortality (P<.05). In the adjusted model, the increased all-cause mortality risk ranged from 47% to 77% based on an ASCVD risk of 20% or higher and 7.5% or higher, respectively. Those with an ASCVD score of 7.5% or higher had a 3-fold increased risk of CVD-specific mortality. The 10-year predicted risk of a first ASCVD event via the PCR equations was associated with all-cause and CVD-specific mortality among those free of CVD at baseline. In this American adult sample, the PCR equations provide evidence of predictive validity.