[Biomarkers of functional class in systolic heart failure: the relevance of copeptin].

INTRODUCTION Functional class is an important predictor of prognosis in chronic heart failure (CHF). However, it is often subjective and poorly reproducible. OBJECTIVE We sought to identify diagnostic markers of high functional class. METHODS We prospectively studied 37 patients with symptomatic CHF and ejection fraction<40%. The study protocol included clinical evaluation, echocardiography (M-mode, 2D, Doppler and tissue Doppler) and laboratory tests including copeptin, vasopressin and NT-proBNP. We compared patients in NYHA class II with those in NYHA class>II. Overall mortality was assessed at 18 months. RESULTS Mortality was higher in the more advanced symptomatic stages (p<0.05). Patients in NYHA class>II had higher creatinine, copeptin and NT-proBNP levels (p<0.05). E/E', E-septum distance, pulmonary artery systolic pressure (PASP) and inferior vena cava (IVC) dimensions were also significantly greater (p<0.05). The biomarkers copeptin (area under the curve [AUC]=0.76, p<0.01) and NT-proBNP (AUC=0.81, p<0.01) and the echocardiographic parameters PASP (AUC=0.88, p<0.01) and IVC inspiratory diameter (AUC=0.91, p<0.01) showed the best performance for diagnosis of functional class>II. In multivariate regression analysis only PASP and serum creatinine were independent predictors of NYHA functional class>II. CONCLUSION Copeptin and NT-proBNP have high sensitivity and specificity in the diagnosis of functional classes with prognostic impact and may be useful in defining a standardized functional classification. The structural and hemodynamic echocardiographic changes associated with NYHA class>II were left ventricular filling pressure, PASP and central venous pressure.