The invention provides a method of treating or preventing heart failure or a disease or condition associated with heart failure comprising administering an effective dose of an apelin peptide or APJ receptor ligand to the subject. According to certain embodiments of the invention the apelin peptide is administered chronically. In certain embodiments of the invention the apelin peptide is administered in an amount effective to improve at least one hemodynamic parameter or prognostic variable for heart failure. Clinical conditions associated with heart failure include, but are not limited to, atherosclerosis, restenosis, ischemic cardiovascular diseases, idiopathic or viral cardiomyopathy, and the like.