Objective: To examine the relationship of depression severity to circulating endothelin-1 (ET-1), which has previously been linked to plaque rupture and postacute coronary syndrome (ACS) survival. Depression carries an independent two- to four-fold increased risk of early morbidity and mortality after ACS. The pathway(s) linking depression to event-free survival remains to be determined.
Methods: Patients with documented history of coronary artery disease (n = 101) provided a resting morning blood sample that was assayed for ET-1, and they completed the Beck Depression Inventory (BDI). ET-1 was treated as a log-transformed continuous variable (logET-1), and as a dichotomous variable using a post-ACS risk threshold previously reported (≥1.16 fmol/mL).
Results: BDI score was related to logET-1 in both unadjusted and adjusted models. In addition, unadjusted and adjusted logistic regression models with dichotomous ET-1 revealed that, for each point increase in BDI score, there was approximately a 14% increased likelihood of being at or above ET-1 risk threshold. Secondary logistic regression models demonstrated a >3.5-fold likelihood of being at or above this risk threshold in association with a BDI score of ≥10.
Conclusions: Depression symptom severity predicts ET-1 elevation that has previously been linked to post-ACS survival, with the greatest risk of elevation among those patients with worse depression symptoms. This link may identify a vulnerability to triggered ACS and poorer survival associated with depression. Future research should establish whether the observed relationship of depressive symptoms to ET-1 level mediates the link between depression and survival.
ACS = acute coronary syndrome; BDI = Beck Depression Inventory; β blocker = beta-blocking medication; CAD = coronary artery disease; ET-1 = endothelin-1; logET-1 = log transformed endothelin-1; SAS = statistical analysis software; TNF-α = tumor necrosis factor-α.