NT-proBNP and New Biomarkers in Patients With Dyspnea and/or Peripheral Edema

The objectives of this study are to: * Evaluate the sensitivity and specificity of NT-proBNP (N-terminal prohormone brain natriuretic peptide) and new biomarker measurements for the diagnosis of heart failure in patients with acute dyspnea and/or edema. * Determine the exact biomarker cut-off point(s) for the differentiation of healthy persons, patients with heart failure and patients with dyspnea of other origin. * Evaluate treatment costs in patients with dyspnea under special consideration of NT-proBNP measurement.