The association between cognitive function trajectories and all-cause mortality in middle-aged and older Chinese adults with cardiovascular disease: A longitudinal study from CHARLS.

Objective: To identify distinct multi-year cognitive function trajectories in middle-aged and older Chinese adults with established cardiovascular disease (CVD) and evaluate their independent associations with all-cause mortality. Methods: This prospective study utilized data from five waves (2011-2020) of the China Health and Retirement Longitudinal Study (CHARLS). A total of 1464 participants aged ≥45 years with CVD were included. Global cognitive scores (range 0-21) were assessed at three time points (2011, 2013, and 2015). A Longitudinal K-means clustering algorithm with Dynamic Time Warping was employed to identify cognitive trajectories. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs) for all-cause mortality during a mean follow-up of 4.7 years. Results: Four distinct cognitive trajectories were identified: High-Baseline-Relatively-Stable (39.1 %), Mid-High-Baseline-Significant-Improvement (31.2 %), Mid-Baseline-Rapid-Decline (16.7 %), and Low-Baseline-Relatively-Stable (13.0 %). Using the Mid-High-Baseline-Significant-Improvement group as the reference, both the Mid-Baseline-Rapid-Decline trajectory (adjusted HR = 2.01; 95 % CI: 1.32-3.05) and the Low-Baseline-Relatively-Stable trajectory (adjusted HR = 1.82; 95 % CI: 1.10-3.00) were significantly associated with an increased risk of all-cause mortality after adjusting for covariates. The association was notably stronger among participants with hypertension (P for interaction = 0.009). Conclusions: Among middle-aged and older adults with CVD, trajectories characterized by rapid cognitive decline or persistently low function are powerful, independent predictors of all-cause mortality. In contrast, cognitive improvement is not associated with excess mortality risk. These findings underscore the prognostic importance of dynamic cognitive assessment and suggest that monitoring cognitive trajectories may aid in the risk stratification of CVD patients.