Cardiovascular Disease Incidence and Risk Factor Contributions in Adults Aged 45 to 59 Years With Low 10-Year and High 30-Year Risk: Findings From REGARDS

BACKGROUND: The American Heart Association's Predicting Risk of Cardiovascular Disease (CVD) Events equations enable 30-year CVD risk estimation for adults 30 to 59 years of age, facilitating the identification of individuals with low 10-year but high 30-year risk. Little is known about the characteristics and determinants of incident CVD in adults within this predicted risk group. METHODS: We examined participants aged 45 to 59 years without prevalent total CVD from the REGARDS study (Reasons for Geographic and Racial Differences in Stroke). Participants were categorized into 3 groups based on the Predicting Risk of CVD Events total CVD risk equations: low 10-year/low 30-year predicted risk (<7.5%/<20%), low 10-year/high 30-year predicted risk (<7.5%/≥20%), and high 10-year predicted risk (≥7.5%). All analyses were sex-stratified. Using adjudicated events for total CVD (atherosclerotic CVD or heart failure), we accounted for the competing risk of non-CVD death to calculate the 10-year cumulative incidence of total CVD for the 3 risk groups. Population attributable risk quantified the contribution of risk factors for the low 10-year/high 30-year risk group. RESULTS: Among 6761 participants, 41.9% were categorized as low 10-year/high 30-year risk (mean age [SD], 55.2 [3.4] years; 52.8% female). Over 10 years, the cumulative incidence of total CVD was higher in the low 10-year/high 30-year risk group compared with those with low 10-year/low 30-year risk in both women (4.8% versus 1.8%) and men (6.0% versus 1.5%). Hypertension was the leading contributor to CVD events among participants with low 10-year/high 30-year predicted risk, accounting for 57.8% (95% CI, 45.1%-70.0%) of events in women and 28.9% (95% CI, 14.8%-43.2%) in men. CONCLUSIONS: Using Predicting Risk of CVD Events 30-year predicted total CVD risk identified a subgroup of younger adults with low 10-year and high 30-year risk who may benefit from earlier preventive interventions. Hypertension was the leading contributor to CVD in this risk category.