Depression and poor outcome after an acute coronary event: Clarification of risk periods and mechanisms

OBJECTIVE: Lifetime depression and depression around the time of an acute coronary syndrome event have been associated with poor cardiac outcomes. Our study sought to examine the persistence of this association, especially given modern cardiac medicine's successes. METHODS: For 332 patients admitted for an acute coronary syndrome, a baseline interview assessed major depression status, and psychological measures were administered. At 1 and 12 months post-acute coronary syndrome event, telephone interviews collected rates of hospital readmission and/or death and major depression status, while biomarker information was examined using medical records. RESULTS: The 12-month mortality rate was 2.3% and cardiac readmission rate 21.0%. Depression subsequent to an acute coronary syndrome event resulted in a threefold and 2.5-fold increase in 1-month and 12-month odds of cardiac readmission or death, respectively. No relationship with past depressive episodes was found. Poor sleep was associated with higher trait anxiety and neuroticism scores and with more severe depression. CONCLUSION: Lifetime depression may increase the risk of depression around the time of an acute coronary syndrome but not influence cardiac outcomes. We suggest that poor sleep quality may be causal or indicate high anxiety/neuroticism, which increases risk to depression and contributes to poor cardiac outcomes rather than depression being the primary causal factor.