Effective treatment of depression improves post-myocardial infarction survival

To examine the contribution of treatment resistant depression (TRD) to mortality in depressed post-myocardial infarction (MI) patients independent of biological and social predictors.

This secondary analysis study utilizes the Enhancing Recovery in Coronary Heart Disease (ENRICHD) clinical trial data. From 1834 depressed patients in the ENRICHD study, there were 770 depressed post-MI patients who were treated for depression. In this study, TRD is defined as having a less than 50% reduction in Hamilton Depression (HAM-D) score from baseline and a HAM-D score of greater than 10 in 6 mo after depression treatment began. Cox regression analysis was used to examine the independent contributions of TRD to mortality after controlling for the biological and social predictors.

TRD occurred in 13.4% (n = 103) of the 770 patients treated for depression. Patients with TRD were significantly younger in age (P = 0.04) (mean = 57.0 years, SD = 11.7) than those without TRD (mean = 59.2 years, SD = 12.0). There was a significantly higher percentage of females with TRD (57.3%) compared to females without TRD (47.4%) [χ(2) (1) = 4.65, P = 0.031]. There were significantly more current smokers with TRD (44.7%) than without TRD (33.0%) [χ(2) (1) = 7.34, P = 0.007]. There were no significant differences in diabetes (P = 0.120), history of heart failure (P = 0.258), prior MI (P = 0.524), and prior stroke (P = 0.180) between patients with TRD and those without TRD. Mortality was 13% (n = 13) in patients with TRD and 7% (n = 49) in patients without TRD, with a mean follow-up of 29 mo (18 mo minimum and maximum of 4.5 years). TRD was a significant independent predictor of mortality (HR = 1.995; 95%CI: 1.011-3.938, P = 0.046) after controlling for age (HR = 1.036; 95%CI: 1.011-1.061, P = 0.004), diabetes (HR = 2.912; 95%CI: 1.638-5.180, P < 0.001), heart failure (HR = 2.736; 95%CI: 1.551-4.827, P = 0.001), and smoking (HR = 0.502; 95%CI: 0.228-1.105, P = 0.087).

The analysis of TRD in the ENRICHD study shows that the effective treatment of depression reduced mortality in depressed post-MI patients. It is important to monitor the effectiveness of depression treatment and change treatments if necessary to reduce depression and improve cardiac outcomes in depressed post-MI patients.