Heart failure (HF) is among the most common causes of death in patients with type 2 diabetes (T2D). Ketones, 3-hydroxybutyrate (3-OHB), have shown to have beneficial hemodynamics effect in patients with hearth failure with reduced ejection fraction. However, this have never been investigated in patients with heart failure with preserved ejection fraction (HFpEF).

In this study we would like to investigate the effect of 14 days modulation of circulating ketone body levels on cardiac function and exercise capacity in patients with HFpEF and T2D.

Inclusion Criteria:

• Type 2 diabetes

• LVEF > 40 %

• a clinical diagnosis of HFpEF and/or left ventricular hypertrophy (posterior wall thickness > 12 mm) and/or previous myocardial infarction

• age ≥ 18 years old,

• one of the following criteria (a-d) should be fulfilled:

  1. Echocardiographic signs of diastolic dysfunction E/e' > 8
  2. Septal e ́< 7 cm/s and/or lateral e ́ < 10 cm/s
  3. Left atrium volume index ≥34 mL/m2 and/or left atrial diameter > 4 cm
  4. NT-proBNP > 125 pg/ml.

Exclusion Criteria:

• Insulin treatment, inability to give informed consent