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. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12888-016-0986-3) contains supplementary material, which is available to authorized users.