Depressive Symptoms Affect the Relationship of N-Terminal Pro B-Type Natriuretic Peptide to Cardiac Event-Free Survival in Patients With Heart Failure

Background: Both N-terminal pro B-type natriuretic peptide (NT-pro BNP) and depressive symptoms independently predict cardiac events in heart failure (HF) patients. However, the relationship among NT-pro BNP, depressive symptoms, and cardiac event is unknown. Methods and Results: Blood was drawn to measure NT-pro BNP and depressive symptoms were measured by the Patient Health Questionnaire 9 (PHQ-9) among 210 patients with HF. Data about cardiac event-free survival were collected for the average follow-up period of 397 days. Cox proportional hazards regression with survival curves were used to determine the relationship of NT-pro BNP and depressive symptoms to cardiac event-free survival. Higher NT-pro-BNP confers greater risk of cardiac events among those with depressive symptoms than those without depressive symptoms (P for the interaction = .029). Patients with NT-pro BNP >581 pg/mL and total PHQ-9 score ≥10 had a 5.5 times higher risk for cardiac events compared with patients with NT-pro BNP ≤581 pg/mL and total PHQ-9 score < 10 (P = .001). Conclusions: The prognostic association of NT-pro BNP with cardiac event-free survival in patients with HF differed by the presence of depressive symptoms. Monitoring and treatment of depressive symptoms may be important for improving cardiac event-free survival in patients with HF.