Onset and recurrence of depression as predictors of cardiovascular prognosis in depressed acute coronary syndrome patients: a systematic review.

BACKGROUND: Depression after acute coronary syndrome (ACS) is associated with worse cardiac outcomes. This systematic review evaluated whether depressed ACS patients are at differential risk depending on the recurrence and timing of onset of depressive episodes.
METHODS: MEDLINE, EMBASE and PsycINFO were searched from inception to 11 April 2009. Additionally, reference lists and recent tables of contents of 34 selected journals were manually searched. Eligible studies evaluated cardiovascular outcomes for subgroups of ACS patients with depression or depressive symptoms according to recurrence or onset.
RESULTS: Six studies were included that reported outcomes for subgroups of ACS patients with first-ever versus recurrent depression. Four of these reported also outcomes for post-ACS onset versus pre-ACS onset depression, and incident versus nonincident depression. Worse outcomes (odds ratio >1.4) were reported for ACS patients with first-ever depression in 3 of 6 studies (1 study p < 0.05), for patients with post-ACS onset depression in 3 of 4 studies (1 study p < 0.05, but better outcomes in one study) and for patients with incident depression in 2 of 4 studies (no studies p < 0.05).
CONCLUSIONS: Although it is still suggested that ACS patients with first and new-onset depression are at particularly increased risk of worse prognosis, the inconsistent results from the studies included in this systematic review show that there is no consistent evidence to support such statements.