Study Aim is creation of the Hospital Register of patients with heart failure with preserved ejection fraction (HFpEF) for a comprehensive assessment of the influence of gender characteristics, clinical and anamnestic factors, body composition, topical characteristics of congestion, instrumental data and markers of cellular inflammation and stress on immediate and long-term outcomes in patients with acute decompensated heart failure with preserved ejection fraction. During the study it is planned to assess gender, clinical and anamnestic indicators preceding hospitalization of patients in the hospital; characterize the features of comorbid status in the studied group of patient; study the features of drug therapy at the prehospital stage and during hospitalization in the study group of patient; assess adverse hospital outcomes and outcomes 6 months after hospital discharge and identify factors associated with them; assess body composition in patients with acute decompensated heart failure with preserved ejection fraction in obese patients upon admission to the hospital; characterize the severity and topical characteristics of congestion and compare with the phenotypes of acute decompensation of heart failure; asess adverse in-hospital outcomes and outcomes 6 months after hospital discharge and identify factors associated with them; conduct a clinical and instrumental examination of patients diagnosed with compensated and decompensated HFpEF, verified by echocardiography at rest, as well as in patients with HFpEF verified after an additional diastolic stress test with assessment of intracardiac hemodynamic; analyze the serum concentrations of biochemical markers associated with cellular stress in these groups of patients, as well as in the control group of apparently healthy people; conduct an analysis of associations of biomarker levels with clinical characteristics of patients, the presence of comorbid diseases, including obesity, as well as with data from instrumental examination methods; assess the diagnostic capabilities of HFpEF, defined by various criteria, based on the concentration of the new biomarkers The results obtained will allow us to evaluate the characteristics of the course and outcomes of the disease in Moscow patients, depending on the phenotype of acute decompensation of HFpEF, hospitalized in the hospital during the study period. It is expected to identify phenotypes of acute decompensation of HFpEF that affect the duration of hospitalization and the development of adverse outcomes in the hospital and long-term period of the disease.