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.
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