Several studies are now on the way evaluating the effects of aliskiren in patients with both systolic and diastolic heart failure. The Atmosphere [88] is currently investigating the effects of aliskiren compared to and on top of Enalapril on morbidity and mortality in patients with systolic heart failure, and the ASTRONAUT study is investigating the effect of aliskiren in the acute HF setting [89]. Studies on patients with diastolic heart failure are on their way as well. The evidence for a potential effect of renin blockade in diastolic heart failure is, however, scarce. Patients with diastolic heart failure tend to have a higher PRA than healthy controls, although not as high as patients with systolic HF [90]; however, this may be due to concomitant medication. Moreover, ACEi and ARB have proven little benefit in these patients so far [91–93]. The effects of direct renin inhibition remain to be investigated.