Heart failure (HF) is a clinical syndrome of exercise intolerance and/or congestion. The management of heart failure with reduced ejection fraction (HFrEF) has improved over the last decades. In contrast, little progress has been made in identifying evidence-based, effective treatments for heart failure with preserved ejection fraction (HFpEF, LVEF >50%). Treatments proven effective in HFrEF have failed to show significant benefit in patients with HFpEF. Potential contributors include an incomplete understanding of pathophysiology and poor matching of therapeutic mechanisms. The challenges of the use of diagnostic criteria, prognostic evaluation and treatment highlight the need for more research in this field.