Perceived Social Support, Heart Rate Variability, and Hopelessness in Patients With Ischemic Heart Disease

Cardiovascular disease is the leading cause of death worldwide, with ischemic heart disease (IHD) the leading cause of cardiovascular mortality. Persons with IHD suffering from psychological distress, including hopelessness, are more likely to die from IHD. Following a stressful event, the vagus nerve enables activation of either a sympathetic (fight/flight) or parasympathetic (rest/digest) response. Heart rate variability (HRV), the beat-to-beat variability between normal successive heart beats, is a biomarker of both adaptive and maladaptive reactions to stress. Decreased HRV predicts greater risk for morbidity and mortality and is associated with poor mental health outcomes in persons with IHD. As stated by polyvagal theory, HRV may be influenced by social support. Decreased perceived social support (PSS), a social determinant of cardiovascular risk, is predictive of increased morbidity and mortality in persons with IHD. Decreased PSS has been associated with hopelessness in patients with cancer, but this relationship has not been studied in IHD beyond the applicant's small pilot study of patients with hopelessness. Hopelessness, a negative outlook and sense of helplessness about the future, is present in 27-52% of patients with IHD. This is of grave concern, because hopelessness is associated with a 3.4 times increased risk of mortality and nonfatal myocardial infarction in patients with IHD, independent of depression. This research focuses on understanding the biological (HRV) and social (PSS) aspects of hopelessness, with the long-term goal of developing and testing novel interventions to reduce the adverse effects of hopelessness and improve health outcomes in patients with IHD. Participants for this cross-sectional study will be recruited while hospitalized for an IHD event. Participants will include patients who report moderate to severe hopelessness from the sponsor's NIH-funded study (n = 225); additional patients with minimal to no hopelessness will be recruited and enrolled by the applicant (n = 45). Data collection will take place remotely two weeks after hospital discharge. Specific aims include: Aim 1) Evaluate the relationship between HRV and hopelessness in patients with IHD; Aim 2) Determine the relationship between PSS and hopelessness in patients with IHD; and Aim 3) Explore the possible mediating effect of HRV on the relationship between PSS and hopelessness in patients with IHD.