Abstract 16350: Predicted versus Observed 10-year Cardiovascular Event Rates in a Rural Population-Based Health Program: The Heart of New Ulm Project

Abstract

Introduction: Assessment of 10-year ASCVD risk via the Pooled Cohorts Equation (PCE) is a standard component of the clinician-patient risk discussion to aid treatment decisions for the primary prevention of ASCVD. However, calibration of the PCE to modern populations remains a concern. Methods: We studied a sample of individuals participating in the Heart of New Ulm (HONU) Project, a population-based health program aimed at reducing ASCVD risk in a rural, agricultural community of New Ulm, Minnesota. HONU collected baseline survey data on 5,221 individuals in 2009. For this analysis, we included participants who were aged 40-79 years, free of ASCVD at baseline and had adequate data to calculate 10-year ASCVD risk. New Ulm is served by a single healthcare system, allowing surveillance via electronic health records (EHR). EHR data and state death records were used to determine rates of non-fatal myocardial infarction and stroke, and ASCVD death from 2010-2019. ASCVD event rates were compared to estimated 10-year risks calculated using the PCE, and stratified by sex and clinically relevant risk categories. Results: The sample (n=2,819, mean age 56.1 ± 9.9 years, 59.6% female) had a low prevalence of tobacco use (8.1% current smokers), diabetes (6.5%) and higher prevalence of hypertension (44.4%) and hyperlipidemia (56.6%). The median estimated 10-year ASCVD risk for the entire sample was 5.7% (interquartile range 2.3 -13.5%) with an observed 10-year ASCVD event rate of 3.4%. ASCVD rates were lower than predicted across all risk categories in both men and women, especially in those with a 10-year risk ≥7.5% (Table). Conclusion: In a rural sample exposed to ASCVD risk reduction efforts, observed rates of ASCVD were substantially lower compared to estimated ASCVD risk. The uncertainty of current risk models and the potential for significantly lower than predicted ASCVD event rates in certain populations should be included in the clinician-patient risk discussion.