Depressive symptoms and functional decline following coronary interventions in older patients with coronary artery disease: a prospective cohort study

BACKGROUND: Depressive symptoms are prevalent in patients with coronary artery disease (CAD). It is unclear, however, how depressive symptoms change over time and the impact of these changes on long-term functional outcomes. We examined the association between different trajectories of depressive symptoms over 1 year and change in functional status over 30 months among patients undergoing coronary angiography. METHODS: This was a prospective cohort study of 350 patients aged 60 and older undergoing non-emergent cardiac catheterization (October 2003-February 2007). A dynamic measure of significant depressive symptoms (i.e., Geriatric Depression Scale score 5+) capturing change over 12 months was derived that categorized patients into the following groups: (i) no clinically important depressive symptoms (at baseline, 6 and 12 months); (ii) baseline-only symptoms (at baseline but not at 6 and 12 months); (iii) new onset symptoms (not at baseline but present at either 6 or 12 months); and, (iv) persistent symptoms (at baseline and at either 6 or 12 month assessment). Primary outcomes were mean change in Older Americans Resources and Services (OARS) instrumental (IADL) and basic activities of daily living (BADL) scores (range 0-14 for each) across baseline (pre-procedure) and 6, 12, and 30 months post-procedure visits. RESULTS: Estimates for the symptom categories were 71 % (none), 9 % (baseline only), 8 % (new onset) and 12 % (persistent). In adjusted models, patients with persistent symptoms showed a significant decrease in mean IADL and BADL scores from baseline to 6 months (-1.32 [95 % CI -1.78 to -0.86] and -0.63 [-0.97 to -0.30], respectively) and from 12 to 30 months (-0.79 [-1.27 to -0.31] and -1.00 [-1.35 to -0.65], respectively). New onset symptoms were associated with a significant decrease in mean IADL scores at 6 months and from 6 to 12 months. Patients with no depressive symptoms showed little change in scores whereas those with baseline only symptoms showed significant improvement in mean IADL at 6 months. CONCLUSIONS: Patients with persistent depressive symptoms were at greatest risk for worse functional status 30 months following coronary interventions. Proactive screening and follow-up for depression in this population offers prognostic value and may facilitate the implementation of targeted interventions.