Cognitive Status and Initiation of Lifestyle Changes Following Acute Coronary Heart Syndrome: A Dissertation

Abstract

Background: Cognitive impairment is prevalent in survivors of acute coronary syndrome (ACS) and increases risk for poor outcomes. Lifestyle changes are recommended to patients after ACS to reduce their risk for recurrent events, but cognitively impaired patients may encounter difficulties initiating these changes. This dissertation had three aims: (1) to examine cognitive status as a predictor of lifestyle changes after ACS, (2) to examine whether caregiver support moderates the association of cognitive status and initiation of lifestyle changes, and (3) to assess the reliability of self-reported lifestyle changes in cognitively impaired patients through comparison of their reports of lifestyle change with those from their caregivers. Methods: For aims 1 and 2, Poisson regression with robust error variance was used to examine the association of cognitive status and caregiver support with patient-reported initiation of five lifestyle changes (improving diet, increasing exercise, quitting smoking, reducing stress, and attending cardiac rehabilitation) in 881 patients from TRACE-CORE, a prospective longitudinal observational study of outcomes in ACS. For aim 3, pilot data from 78 patient-caregiver dyads from TRACE-CARE, an ancillary substudy, were used to examine whether patient-caregiver congruence on reports of lifestyle changes varied according to patients’ cognitive function. Results: Patient-reported rates of lifestyle change did not vary according to cognitive status, except for participation in cardiac rehabilitation. Caregiver support improved patient-reported rates of lifestyle change among cognitively intact patients but not cognitively impaired patients. Patients’ cognitive function was positively associated with patient-caregiver congruence on reports of initiation of lifestyle changes and patients with decreased cognitive function tended to over-report initiation of lifestyle changes compared to reports by their caregivers. Conclusion: Although cognitive status was not associated with initiation of most lifestyle changes and the influence of caregiver support on initiation of lifestyle changes was only beneficial to cognitively intact patients in this cohort of ACS patients, these null findings may be explained by the questionable validity of self-report in cognitively impaired patients. This dissertation yields new knowledge about secondary prevention in ACS patients and provides insight into the challenges of conducting patient-reported outcomes research in cognitively compromised populations.