The investigators wish to test a hypothesis that patients with HFpEF have different characteristics on echo, cardiac MRI and plasma protein & chemical profiles compared to HFrEF and healthy volunteers.

Large scale prospective studies incorporating cardiac MRI, echocardiography and plasma sampling are currently lacking in HFpEF. The main aims of our study are to:

1. better phenotype and characterise HFpEF (also comparing with HFrEF and age- and sex- matched healthy controls)
2. provide mechanistic insights into pathophysiology
3. describe potential biomarkers and their relation to relevant clinical outcomes (exercise capacity, heart failure quality of life and prognosis)

Inclusion Criteria:

• Clinical features of heart failure or prior radiographic evidence in the absence of symptoms And Either ejection fraction > 50% (for HFpEF arm) or ejection fraction < 40% (for HFrEF arm)

Exclusion Criteria:

• Myocardial infarction within the preceding 6 months
• Suspected or confirmed cardiomyopathy (e.g. hypertrophic, infiltrative)
• Suspected or confirmed constrictive pericarditis
• Significant native valve disease (≥ moderate severity)
• Known Significant lung disease (documented or FEV1< 30% or FVC < 50%)
• Non-cardiovascular co-morbidity likely to cause death within 6 months (e.g. malignancy)
• Significant renal failure (estimated GFR < 30 ml/min/m2)
• Patient inability to provide informed consent (e.g. dementia)

Subjects with heart failure from Hospital (including ward patients and out-patients clinic)