Abstract P3137: Psychological Factors and Coronary Atherosclerosis Progression in the Multi-Ethnic Study of Atherosclerosis

Abstract

Background: Psychological distress increases the risk of acute cardiac events, but studies are conflicting on whether it causes atherosclerotic progression. In previous longitudinal studies, missing outcome measures across time may have resulted in selection bias. Objective: To estimate the longitudinal association of psychological factors with coronary atherosclerotic burden. Methods: In the Multi-Ethnic Study of Atherosclerosis (MESA), we examined psychological exposures via validated scales (anger trait, anxiety trait, chronic stress, lifetime discrimination, everyday discrimination, and depression) and subclinical atherosclerosis with coronary artery calcium (CAC) at baseline for all participants, who were invited to repeat their CAC scores at four subsequent visits. Linear mixed models tested the association of psychological scales with atherosclerosis progression by the slope of log-transformed CAC score over time, accounting for confounders in the causal model (age, gender, race, income, work status, neighborhood). As a sensitivity analysis to adjust for selection bias, we ran the model after multiple imputations by chain equations of the missing CAC scores at the follow-up visits. Results: The 6,814 MESA participants had a median age of 62 years (IQR53-70), and 47% were males. All participants had a baseline CAC Score measurement: 746 had only the baseline, 2452 participants had two CAC scores, 2831 had three, and 785 had four. The mean time between the baseline and the last CAC score was 6.5 ± 3.5 years. For a standard deviation (SD) increase in each psychological scale, the change in CAC score per visit was estimated to be near zero (Figure 1 shows the 95% confidence intervals of the percent change in CAC Score by SD increment in each scale). The number of missing CAC scores was associated with a more adverse socioeconomic and cardiometabolic risk profile and higher baseline CAC Scores, suggesting selection bias. The analysis performed after imputing missing CAC scores showed consistent associations between higher levels of psychological scales and progression of the CAC scores over time (Figure 1). Conclusion: While no association was found in the analysis of observed outcomes, associations emerged after outcome imputation to account for selection bias due to missing data. Future studies should minimize missing values of the outcome to avoid biased results.