Clinical and prognostic implications of self-rating depression scales and plasma B-type natriuretic peptide in hospitalised patients with chronic heart failure

BACKGROUND: Depression is common among patients with chronic heart failure (CHF) and has been independently associated with a poorer prognosis. PURPOSE: This study evaluated the clinical and prognostic value of depression scales (Beck Depression Inventory (BDI), Zung Self-rating Depression Scale (Zung SDS)) along with plasma B-type natriuretic peptide (BNP) in CHF. METHODS: 155 hospitalised CHF patients (ejection fraction 26.9% (SD 6.4%)) were studied by depression (BDI, Zung SDS) and functional questionnaires (Kansas City Cardiomyopathy Questionnaire (KCCQ), Duke Activity Status Index (DASI)), BNP and 6-minute walk test (6MWT). Patients were followed for 6 months for cardiovascular events, including death from any cause or rehospitalisation for CHF decompensation. RESULTS: Seventy-six (49%) patients with depressive symptoms, as estimated by both scales, had significantly lower DASI and KCCQ scores (13.2 (SD 9.9) vs 23.6 (SD 13.0) and 26.6 (SD 15.0) vs 45.0 (SD 17.0), respectively; p<0.001), higher BNP (921 (SD 889) vs 439 (SD 267) pg/ml, p = 0.001) and reduced 6MWT (270 (SD 130) vs 337 (SD 133); p<0.001). According to logistic regression analysis, Zung SDS and BNP were independently associated with adverse clinical outcomes; values of Zung SDS >or=40 and of BNP >or=290 pg/ml predicted future events with a sensitivity of 82% and 94% and a specificity of 45% and 46%, respectively. The combination of Zung SDS plus BNP had an additive prognostic value, predicting events with a sensitivity of 77% and a specificity of 70% (event-free survival: Zung <40 and BNP <290 pg/ml; 170 (SD 9) days; Zung >or=40 and BNP <290 pg/ml, 159 (SD 14) days; Zung <40 and BNP >or=290 pg/ml, 118 (SD 15) days; Zung >or=40 and BNP >or=290 pg/ml, 73 (SD 8) days, p<0.001). CONCLUSIONS: CHF patients with depressive symptoms have impaired physical activity, associated with excessive neurohormonal activation. Among the studied scales, Zung SDS seemed to independently predict clinical outcome, especially in patients with increased plasma BNP concentration. Hence, the combination of those two modalities provides a practical means for risk stratification in CHF.