AVP and chronic obstructive pulmonary disease: Recent studies by our group and others have suggested Copeptin and, therefore, the vasopressin system to be major determinants of outcome in patients where dyspnea is often the major symptom such as in acute myocardial infarction, in chronic heart failure and even in patients with community-acquired pneumonia and exacerbated chronic obstructive pulmonary disease [17-22,29].