Predictors of Poor Prognosis in HFpEF

Inclusion Criteria: 1. Signed and data informed consent; 2. New York Heart Association (NYHA) class II-III heart failure; 3. Left ventricular ejection fraction \> 50%; 4. Elevated LV filling pressures assessed by echocardiography at rest or at peak exercise. Exclusion Criteria: 1. Evidence of myocardial ischemia during stress echocardiography; 2. Significant lesions of the main coronary arteries; 3. Genetic forms of HFpEF (HCM, amyloidosis, Fabry disease, glycogen storage diseases etc.); 4. Peripartum cardiomyopathy, chemotherapy-induced cardiomyopathy, viral myocarditis, isolated right-sided HF without left-sided structural disease, constrictive pericarditis, significant pericardial effusion; 5. Significant lung disease (severe lung disease requiring home oxygen or chronic oral steroid therapy); 6. Primary pulmonary artery hypertension; 7. Significant left-sided structural valve disease; 8. Anemia (Hb \< 100 g/L); 9. Impaired renal function, defined as estimated glomerular filtration rate (eGFR) \<30 mL/min/1.73 m2 (CKD-EPI); 10. Non-cardiac conditions that complicate/exclude participation in the study; 11. Exacerbation of heart failure less than 3 months prior to study entry.