Early life stress and autonomic response to acute mental stress in individuals with coronary heart disease

Early life stress (ELS) has been associated with an increased risk of cardiovascular disease. We examined whether ELS was associated with autonomic function and stress reactivity among individuals with coronary heart disease (CHD). We included patients with stable CHD from two parallel studies, the Mental Stress Ischemia Prognosis Study (MIPS) and the Myocardial Infarction and Mental Stress Study 2 (MIMS2), and assessed ELS using the Early Trauma Inventory-Self-Report-Short Form. Participants underwent a laboratory-based mental stress task while undergoing ambulatory electrocardiographic monitoring. We used multivariate linear regression models to estimate the associations between ELS and heart rate variability (HRV; low frequency [LF], high frequency [HF], and LF and HF [LH] ratio). The analytic sample included 405 MIPS and 284 MIMS2 participants. Most participants endorsed at least one experience of ELS (92.2%). Although we did not observe associations between ELS and HRV outcomes in the overall sample, ELS was associated with lower LH ratio HRV during recovery in the posttraumatic stress disorder (PTSD) subgroup, ELS x PTSD interaction, p = .041. In the MIMS2 subgroup, ELS was associated with lower resting period LF HRV, $\hat{B}$ = -0.16 ln ms² ; 95% CI [-0.31, -0.02]. Exposure to physical trauma was associated with decreased HF HRV overall reactivity only among participants with high to moderate depressive symptoms, $\hat{B}$ = -0.52 ln ms² vs. $\hat{B}$ = 0.01 ln ms² , p = .013. Overall, heterogeneous associations between ELS and HRV emerged, suggesting the need for additional research regarding longer-term ambulatory HRV.