ObjectiveDepression and hostility are significant risk factors for mortality and morbidity after myocardial infarction (MI). Much research is still needed to identify effective ways to reduce emotional distress in patients with cardiovascular disease. This double-blind, placebo-controlled study investigated the efficacy and safety of the antidepressant fluoxetine in patients with depression after their first MI.MethodsFifty-four patients with major depression after MI were randomly assigned to receive a flexible-dose regimen of fluoxetine or placebo for the first 9 weeks of a double-blind, placebo-controlled trial. Patients without serious adverse effects who wished to continue participating in the study were given fluoxetine or placebo for an additional 16 weeks. To evaluate the efficacy of fluoxetine, the 17-item Hamilton Depression Rating Scale (HAMD-17) and the Hostility Scale of the 90-item Symptom Check List (SCL-90) were used as primary measures of outcome. To evaluate the safety of fluoxetine, cardiac function was measured before and after treatment with echocardiography and electrocardiography.ResultsThe a priori difference in antidepressive efficacy (4-point difference in HAMD-17 scores between the fluoxetine and placebo groups) was not met. However, the response rate among patients receiving fluoxetine was significantly greater than that among patients receiving placebo at week 25 (48 vs. 26%,p= .05). Among patients with mild depression (HAMD-17 score ≤21), HAMD-17 scores were significantly different (p< .05) between the fluoxetine and placebo groups at weeks 9 (by 5.4 points) and 25 (by 5.8 points). Also, hostility scores at week 25 were significantly reduced among patients receiving fluoxetine (p= .02). Analysis of electrocardiographic and echocardiographic parameters revealed no decrease in cardiac function as a result of treatment with fluoxetine.Conclusions:Although the overall difference between the fluoxetine and placebo groups was not significant, there was a trend favoring fluoxetine in this relatively small sample. The response rate in the group receiving fluoxetine was comparable with that observed in other studies of patients with cardiovascular disease. In addition, fluoxetine seemed to be particularly effective in patients with mild depression and was associated with a statistically significant reduction in hostility. The results of this study suggest that fluoxetine can be safely used to treat patients with post-MI depression beginning 3 months after the event.