Interleukin-6 as a novel biomarker for the diagnosis of acute decompensated heart failure: a retrospective study

Figures

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  Figure 1. Study protocol. Exclusion criteria included the following: infection, acute myocardial infarction, moderate to severe renal failure (estimated glomerular filtration rate < 60 mL/min per 1.73 m2), malignancies, autoimmune disorders, treatment history of steroids and immunosuppressive drugs, rheumatoid disease, advanced liver disease, and myocarditis. HF, heart failure; ADHF, acute decompensated heart failure; CHF, chronic heart failure.

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  Figure 2. Correlation analyses. All biomarker and clinical variables were log–transformed to approximate normal distribution before analysis. Pearson correlation coefficients (r) and corresponding p-values are shown for each panel. After natural logarithmic transformation, IL-6 was positively associated with NT-proBNP (r = 0.838, p < 0.001) (A), LVEDD (r = 0.446, p < 0.001) (B) and HR (r = 0.618, p < 0.001) (D), and inversely associated with LVEF (r = −0.451, p < 0.001) (C). NT-proBNP, N-terminal pro-B-type natriuretic peptide; IL-6, interleukin-6; LVEDD, left ventricular end-diastolic dimension; LVEF, left ventricular ejection fraction; HR, heart rate.

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  Figure 3. ROC curve of plasma IL-6 for the diagnosis of ADHF. The AUC for IL-6 level was 0.904 (p < 0.001), indicating excellent diagnostic discrimination. The optimal cut-off value for IL-6 was determined to be 5.00 pg/mL. At this cut-off value, the sensitivity, specificity and Youden index for ADHF diagnosis were 81.0%, 87.5% and 0.685, respectively. The diagonal line represents the ROC curve for a test with no discriminative ability (AUC = 0.5). ROC, receiver operating characteristic; ADHF, acute decompensated heart failure; AUC, area under the curve.