Cardiovascular disease (CVD) is a major risk factor for cognitive decline and dementia. We examined whether a higher atherosclerotic cardiovascular disease (ASCVD) risk is associated with faster cognitive decline in Project FRONTIER, a rural cohort.

Participants were aged ≥40 years without baseline CVD and completed two study visits. Primary outcomes were the RBANS Total Score and its domains; secondary outcomes were Executive Interview 25, verbal fluency, Clock Drawing Test (CLOX), and Trail Making Test (TMT) A and B. Primary exposure was the 10-year ASCVD risk per AHA PREVENT equations. We fitted Bayesian mixed-effects models to estimate the interaction between time (in years) and ASCVD risk, adjusting for covariates using brms package in R.

We analyzed data of 383 participants (age 57.74 ± 11.4 years; 75.5 % female; 59.8 % Hispanic; median follow-up 3.00 years, IQR: 2.67–3.64). The time×ASCVD risk interaction for RBANS Total was credibly negative (β = −1.22 points/year per 10 % higher risk, 95 % CrI −1.87 to −0.58). Strongest domain-specific effects were for attention (β = −1.25; 95 % CrI −2.14 to −0.37) and delayed memory (β = −1.36; 95 % CrI −2.16 to −0.05). CLOX suggested a credibly negative interaction (β = −0.39; 95 % CrI −0.62 to −0.16), and TMT-A showed a credibly positive interaction (β = +2.85 s/year; 95 % CrI 1.28 to 4.41).

In this rural cohort, a higher 10-year ASCVD risk was associated with faster decline in global cognition, particularly attention and delayed memory, supporting the potential value of cardiovascular risk monitoring and modification to preserve cognitive function.