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

Abstract

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.