Depression after myocardial infarction is a risk factor for declining health related quality of life and increased disability and cardiac complaints at 12 months.

OBJECTIVE: To study the prospective effects of post-myocardial infarction (MI) depressive disorder on health status, including self reported cardiac symptoms, disability, and health related quality of life, at 12 months after MI while controlling for cardiac condition and health status at three months after MI. METHODS: Longitudinal study of a cohort of 468 adults with MI recruited from four hospitals in the north of The Netherlands between September 1997 and September 2000. Assessment of depressive disorder in the year after MI according to International classification of disease, 10th revision criteria. Assessment of health status at three and 12 months by the RAND 36 item health survey, the health complaints scale, self rated cardiac complaints, and disability. RESULTS: Patients with post-MI depressive disorder were more likely than those without to have poor quality of life, more health complaints, more cardiac complaints, and more disability at 12 months' follow up. In multivariate analyses adjusted for cardiac condition, health status at three months, age, sex, and pre-MI depression, the prospective association of post-MI depression with poor health status remained for most of the indicators. Severity of the post-MI depression further contributed to aspects of poor health status. CONCLUSIONS: In a prospective study design, post-MI depression had strong effects on poor health status exceeding the effects of cardiac condition and its short term consequences. Efforts to improve health status after MI should therefore include standard assessment and guideline based treatment of post-MI depressive disorder.

Depression as an independent determinant of decreased heart rate variability in patients post myocardial infarction.

OBJECTIVE: Depression is associated with an increased risk of cardiac morbidity and mortality in patients following myocardial infarction (MI). Our objective was to investigate the potential role of the autonomic nervous system in mediating this detrimental effect. METHODS: The study group consisted of 95 consecutive post-MI patients without depression and 53 post-MI patients with depression. Depressive symptoms were assessed by the Beck Depression Inventory (BDI). Activity of the autonomic nervous system was assessed by analysing heart rate variability (HRV) using 24-hour ambulatory electrocardiographic recordings as obtained three months post MI. RESULTS: Higher age, female gender and left ventricular ejection fraction <0.40 were associated with lower HRV (SDANN, and very-low-frequency and low-frequency power, but not RMSSD and high-frequency power), as was depression. In the multivariate analysis, age and left ventricular ejection fraction but not gender emerged to be independently associated with HRV. After adjustment for these two covariates, depression remained significantly associated with low HRV. CONCLUSIONS: Patients with depression in the present post-MI study are characterised by decreased longer-range HRV compared with the patients without depression, independent of other clinical variables. This observation supports the concept that one of the mechanisms underlying the detrimental effect of depression on post-MI prognosis may be that depression adds to the autonomic derangement post MI.