Objective: To examine the association between anxiety symptoms 3 months after myocardial infarction (MI) and/or new cardiovascular events and death, taking into account established risk factors, and to compare the results with those of the impact of depressive symptoms. Post-MI anxiety symptoms have been associated with a composite outcome of new cardiovascular events or death, but previous studies have not fully adjusted for potential confounders. It remains unclear whether anxiety symptoms are independently associated with both new cardiovascular events and death.
Methods: A population-based cohort study of 896 persons (70% of eligible) with first-time MI between 1 January 2009 and 31 December 2009, completing the Hospital Anxiety and Depression Scale, were followed up until 31 July 2012.
Results: A total of 239 new cardiovascular events and 94 deaths occurred during 1975 person-years of follow-up. Cox proportional hazards models showed that anxiety symptoms were associated with both new cardiovascular events and death in analysis adjusted for age only. The estimates decreased when adjusted for dyspnea score, physical activity, and depressive symptoms, and anxiety symptoms were no longer associated with new cardiovascular events (hazard ratio [HR] = 1.02, 95% confidence interval [CI] = 0.98-1.07) or with death (HR = 0.94, 95% CI = 0.88-1.01). In fully adjusted models, depressive symptoms remained associated with death (HR = 1.13, 95% CI = 1.05-1.21), but not with new cardiovascular events (HR = 1.02, 95% CI = 0.99-1.06).
Conclusions: Post-MI anxiety symptoms were not an independent prognostic risk factor for new cardiovascular events or for death, whereas depressive symptoms were associated with an increased risk of mortality.