Biological aging traits mediate the association between cardiovascular health levels and all-cause and cardiovascular mortality among adults in the U.S. without cardiovascular disease.

The American Heart Association's (AHA) Life's Essential 8 (LE8) metrics provide a framework for assessing cardiovascular health (CVH). This study evaluates the relationship between CVH levels from LE8 and mortality risk, considering biological aging's role. Using data from the NHANES non-CVD adult population, CVH scores were categorized as low (< 50), moderate (50-79), and high (≥ 80) per AHA guidelines. Cox regression model assessed the impact of CVH levels on all-cause and cardiovascular mortality, while examining four aging indicators as mediators. RCS explored the relationships between CVH scores and mortality risk. The model's performance was evaluated using nine machine learning algorithms, with SHAP analysis on the best model to determine CVH score components' importance. Cox regression showed that all-cause mortality rates decreased by 35% for moderate and 54% for high CVH groups compared to low CVH. The high CVH group had a 59% lower cardiovascular mortality rate. Each unit increase in CVH score reduced all-cause and cardiovascular mortality to 0.98 times. RCS analysis revealed a nonlinear trend between CVH scores and mortality risk. Biological aging indicators significantly mediated the CVH-mortality relationship, with PhenoAge (21.57%) and KDM-Age (20.33%) showing the largest effects. The XGBoost model outperformed others, with SHAP analysis ranking CVH components: physical activity, nicotine, blood pressure, BMI, lipids, healthy eating index, blood glucose, and sleep. Higher CVH levels correlate with reduced all-cause and cardiovascular mortality risk, with biological aging mediating these effects. Adhering to AHA's LE8 metrics is recommended to enhance life expectancy in the non-CVD population.