Severe depressive symptoms are associated with elevated endothelin-1 in younger patients with acute coronary syndrome.

Objective: To explore the relationship of depressive symptom severity to circulating endothelin (ET)-1 in younger patients with acute coronary syndrome (ACS). Younger patients report greater depressive symptom severity, which predicts poorer post-ACS prognosis. The pathways linking depression to post-ACS prognosis require further elucidation. ET-1 is a potent endogenous vasoconstrictor which has been previously linked to adverse post-ACS outcomes.

Methods: The sample (n=153) included males ≤ 50 years of age and females ≤ 55 years of age who participated in a larger study. Blood samples for ET-1 assessment were collected within 2-3h of ACS admission. Depressive symptoms were assessed with the Beck Depression Inventory (BDI) II within 2-5 days of admission. ET-1 was treated as a transformed continuous variable (ET-1T). BDI-II scores were classified into four categories using conventional thresholds demarcating mild, moderate, and severe levels of depressive symptoms. The relationship of classified BDI-II score to ET-1T was examined in simple and multivariable linear regression models.

Results: Classified BDI-II score was related to ET-1T in both unadjusted (χ(2)=9.469, p=0.024) and multivariable (χ(2)=8.430, p=0.038) models, with ET-1T being significantly higher in patients with severe depressive symptoms than in those with mild and moderate depressive symptoms.

Conclusions: In this sample of younger post-ACS patients, severe depressive symptoms were associated with elevated ET-1. We acknowledge that the observed association could be eliminated by the inclusion of some unmeasured variable(s). Longitudinal research should examine whether ET-1 mediates the relationship of depressive symptoms to long-term post-ACS outcomes.