One year cumulative incidence of depression following myocardial infarction and impact on cardiac outcome.

BACKGROUND: Major depression has been identified as an independent risk factor for increased morbidity and mortality in mixed patients populations with first and recurrent myocardial infarction (MI). The aim of this study was to evaluate whether incidence of major and minor depression is as high in a population with merely first-MI patients as in recurrent MI populations. Furthermore, it was evaluated whether in first-MI patients major and minor depression, and depressive symptoms, had an impact on cardiac mortality and morbidity up to 3 years post MI.
METHODS: A consecutive cohort of 206 patients with a first MI were included in this study. One month following MI, all patients were interviewed using the Structured Clinical Interview for DSM-IV (SCID-I-R). Three, six, nine and twelve months following MI, patients filled out three psychiatric self-rating scales for depression, the Beck Depression Inventory (BDI), the Hospital Anxiety and Depression Scale (HADS), and the 90-item Symptom Checklist (SCL-90). Patients, exceeding a previously defined cut-off value on at least one of these scales, were reinterviewed using the SCID. The BDI was applied to assess depressive symptoms in relation to cardiac outcome as the SCL-90 and HADS showed similar results. Cardiac outcome was defined as major cardiac event, i.e., death or recurrent MI, and health care consumption, i.e., cardiac rehospitalisation and/or frequent visits at the cardiac outpatient clinic. Depression outcome was assessed from 1 month post MI up to 1 year post MI whereas cardiac outcome was assessed between 1 month and 3 years post MI.
RESULTS: A 1-year incidence of 31% of major and minor depression was found in first-MI patients. The highest incidence rate for both major and minor depression was found in the first month after MI. Compared with nondepressed patients, depressed patients were younger (P=.001), female (P=.04) and were known with a previous depressive episode (P=.002). Neither major/minor depression nor depressive symptoms significantly predicted major cardiac events, but did predict health care consumption (P=.04 and P<.001, respectively).
CONCLUSIONS: Incidence of major and minor depression is similar in this first-MI patients population as in recurrent MI populations. Major/minor depressive disorder nor depressive symptoms predicted neither mortality nor reinfarction.