In ACS, depression a risk factor for poor prognosis

The American Heart Association and other health organizations should consider depression as a risk factor for adverse outcomes in patients with acute coronary syndrome (ACS), according to a recent report published in Circulation, the Journal of the American Heart Association.

The study

Researchers conducted a systematic literature review on depression and adverse medical outcomes following ACS, which included all-cause mortality, cardiac mortality, composite outcomes for mortality, and nonfatal events. They found 53 peer-reviewed studies and four meta-analyses that examined depression and outcomes following ACS. Of the 53 individual studies, 32 reported on depression and all-cause mortality, 12 on depression and cardiac mortality, and 22 on depression and composite outcomes.

The review identified heterogeneity within the studies and meta-analyses in terms of demographic composition, the definition as well as measurement of depression, the follow-up time, and the covariates in the multivariable statistical models.

“Despite this heterogeneity, the preponderance of evidence supports the recommendation that the AHA should elevate depression to the status of a risk factor for adverse medical outcomes in patients with ACS,” the authors concluded.

Assessing depression

In their systematic review, the researchers noted that the studies included a standardized self-report questionnaire for depression or a diagnostic interview. More studies used the self-report questionnaire than the diagnostic interview.

In addition, the most recent meta-analysis indicated that a more pronounced effect of depression on coronary heart disease (CHD) outcomes was found through interviews than through self-report. However, the three earlier meta-analyses found no difference or the opposite to be true, the authors stated.

Also, the depression assessment occurred at various times, usually a couple of days or weeks following the ACS event. In some of the studies, it was not clear whether the depression was assessed at the time of the hospitalization or after discharge.

More study needed

“The committee concurs with an expert panel convened by the National Heart, Lung, and Blood Institute in recommending that future studies of the prognostic values of post-ACS depression should use well-validated questionnaires and structured interviews to assess depression and well-validated cutoff scores and diagnostic criteria to define cases of depression,” the authors noted.

In addition to the use of diagnostic interviews and self-report questionnaires, the researchers suggested that future study designs include greater consistency in defining the outcomes, consideration of the individual end points instead of composite outcomes, and better differentiation between mediators and confounders in multivariable models.