In addition to the blood pressure lowering effects of aliskiren, it may have beneficial effects on blocking the so called RAAS (renin-angiotensin-aldosterone system) at the tissue level. An increase of angiotensin II is associated with progression of heart failure. Although the use of ACE-inhibitors in heart failure shows clinical benefit, an increase in angiotensin II due to an angiotensin II "escape" phenomenon is not desirable. It is not yet known if a direct renin inhibitor can reduce or even prevent the angiotensin II escape phenomenon associated with the use of an ACE-inhibitor. Therefore the study tested the effects of ramipril, aliskiren and the combination of both on levels of angiotensin II in the blood in patients with systolic heart failure