Changes in cognitive versus somatic symptoms of depression and event-free survival following acute myocardial infarction in the Enhancing Recovery in Coronary Heart Disease (ENRICHD) study

Background: Randomized controlled trials focusing on the effects of antidepressant treatment in cardiac patients have found modest effects on depressive symptoms but not on cardiac outcomes. A secondary analysis was conducted on data from the Enhancing Recovery in Coronary Heart Disease trial to assess whether changes in somatic or cognitive depressive symptoms following acute MI predicted event-free survival and whether the results differed per treatment arm (cognitive behavior therapy or care as usual). Methods: Patients who met depression criteria and completed the 6th month depression assessment (n=1254) were included in this study. Measurements included demographic and clinical data and the Beck Depression Inventory at baseline and 6 months. The primary endpoint was a composite of recurrent MI and mortality over 2.4 years (standard deviation=0.9 years). Results: Positive changes (per 1 point increase) in somatic depressive symptoms (HR: 0.95; 95% CI: 0.92-0.98; p=0.001) but not in cognitive depressive symptoms (HR: 0.98; 95% CI: 0.96-1.01; p=0.19) were related to a reduced risk of recurrent MI and mortality after adjustment for baseline depression scores. There was a trend for an interaction effect between changes in somatic depressive symptoms and the intervention (p=0.08). After controlling for demographic and clinical variables, the association between changes in somatic depressive symptoms and event-free survival remained significant in the intervention arm (HR: 0.93; 95% CI: 0.88-0.98; p=0.01) only. Limitations: Secondary analyses. Conclusions: Changes in somatic depressive symptoms, and not cognitive symptoms, were related to improved outcomes in the intervention arm, independent of demographic and clinical variables.