Heart failure is a major health problem with serious consequences on mortality and morbidity worldwide. In chronic heart failure an alteration of the inflammatory state occur. The aim of this study will be to describe the relationship between markers of inflammation in patients with heart failure with preserved ejection fraction, gender differences and advanced age. The study sample will include patients hospitalized in the Unit of General Medicine and Aging with a diagnosis of heart failure based on the guidelines. Clinical and demographic data will be collected from the electronic records of our hospital system. A complete history will be obtained, including the possible etiology of heart failure, cardiac and noncardiac comorbidities, all medications, intracardiac devices, and chronic oxygen treatment. All patients will be documented for peripheral edema, pulmonary rales and jugular vein distension. NYHA (New York Heart Association) class will be identified at discharge. In addition, a blood sample will be taken to obtain a complete panel including total blood count, glycemia, renal function, electrolytes and liver function tests, as per standardized clinical practice. NT-proBNP (Amino-terminal pro Natriuretic Peptide B) will be measured at admission and discharge from the hospital, as per standardized clinical practice. Echocardiograms will be performed by experienced operators of the echocardiography service of our Polyclinic, according to the American Society of Echocardiography guidelines. A single additional blood sample will be collected during one of the normal routine blood draws for all immunological tests. Plasma from each participant will be isolated to determine the concentrations of several cytokines. Circulating lymphocytes will be separated according to Ficoll gradient (peripheral blood mononuclear cells, PBMC) into the two different components of immunity (B and T lymphocytes) with different inflammatory phenotypes Evaluation of enhancer (HS)1,2 polymorphisms and estrogen levels: DNA purifications and amplifications will be performed from an aliquot of the single whole blood sample collected for the evaluation of the inflammatory profile. Genomic DNA will be isolated and 9 SNPs in four specific polymorphic regions of the 3'-1 Regulatory Region (3'RR-1) of the human immunoglobulin (IgH) heavy chain locus will be sequenced. Follow-up will be performed by telephone contacting the patients or their caregivers 90 days after discharge.