Is early- and late-onset depression after acute myocardial infarction associated with long-term survival in older adults? A population-based study

BACKGROUND: Early-onset depression after acute myocardial infarction (AMI) affects short-term survival in clinical samples of patients. There is no information on the impact of early-onset depression or late-onset depression on long-term Survival. OBJECTIVE: To investigate the impact of early- and late-onset depression on survival using administrative data. METHODS: A historical inception cohort design was used, commencing in 1994 with up to eight years of follow-up. A province-wide administrative data set from British Columbia was used to select the cohort and construct the variables. Data regarding hospitalizations, physician visits and prescription drugs were available. All individuals 66 years of age and older who had an AMI in 1994 or 1995 were selected (n=4874). Individuals were categorized as depressed, possibly depressed or not depressed based on physician or hospital visits indicating depression as a diagnosis and/or prescriptions for antidepressants. Early,onset depression was assessed during the first six months post-AMI, and late-onset depression was assessed between six months and five years post-AMI. All-cause mortality Lip to eight years post-AMI was the outcome. RESULTS: Both early- and late-onset depression were associated with long-term mortality. The hazard ratio was 1.34 (95% CI 1.04 to 1.73) for early-onset depression and 1.79 (95% CI 1.38 to 2.35) for late-onset depression. CONCLUSIONS: Both early- and late-onset depression post-AMI were significantly associated with mortality LIP to eight years post-AMI. Depression is a strong independent predictor of post-AMI mortality in older adults.