Depressive symptoms and cardiovascular burden-related mortality among the aged.

Background: Depressive symptoms have been linked to increased cardiovascular mortality among the elderly. This study was aimed to test the independent and additive predictive value of depressive symptoms and B-type natriuretic peptide (BNP), a marker of direct cardiovascular stress and a strong predictor of mortality, together with traditional cardiovascular risk markers on total and cardiovascular mortalities in a general elderly population.

Methods: A total of 508 subjects aged 75 or older participated in the study. The prognostic capacity of depressive symptoms and BNP in regard to total and cardiovascular mortalities was assessed with Cox regression analyses. Depressive symptoms were handled as a dichotomous variable based on the Zung self-rated depression scale score with a cut-off point of 40.

Results: The median follow-up time was 84 months with an interquartile range of 36-99 months. Depressive symptoms reflected susceptibility to all-cause (HR 1·60; 95% CI 1·26-2·04) and cardiovascular mortalities (HR 1·81; 95% CI 1·30-2·52) only in univariable analyses. When cardiovascular illnesses and risk markers were taken into account, depressive symptoms lost their significance as an independent predictor of mortality. BNP as a continuous variable was a significant predictor of both all-cause (HR 1·44; 95% CI 1·22-1·69) and cardiovascular mortalities (HR 1·79; 95% CI 1·44-2·22) in fully adjusted models including depressive symptoms as a covariate.

Conclusions: The prognostic capacity of depressive symptoms is closely linked to cardiovascular morbidity and has no independent power in an elderly general population. BNP remains a strong harbinger of death regardless of depressive symptoms status.