AimsThe renin-angiotensin-aldosterone system (RAAS) represents a key therapeutic target in heart failure (HF) management. However, conventional agents that block this system induce a reflex increase in plasma renin activity (PRA), which may lead to RAAS 'escape'. Direct renin inhibitors (DRIs) have been developed that decrease PRA and thus may provide a greater RAAS blockade. Aliskiren is the first orally active DRI. Plasma levels of B-type natriuretic peptide (BNP) have been observed to be reduced with aliskiren compared with placebo. The aim of the Aliskiren Trial of Minimizing OutcomeS for Patients with HEart failuRE (ATMOSPHERE) study is to evaluate the effect of both aliskiren and enalapril monotherapy and aliskiren/enalapril combination therapy on cardiovascular death and HF hospitalization in patients with chronic systolic HF, NYHA functional class II -IV symptoms, and elevated plasma levels of BNP. MethodsPatients tolerant to at least 10 mg or equivalent of enalapril will undergo an open-label run-in period where they receive enalapril then aliskiren. Approximately 7000 patients tolerating this run-in period will then be randomized 1:1:1 to aliskiren monotherapy, enalapril monotherapy, or the combination. The primary endpoints of ATMOSPHERE are (i) whether the aliskiren/enalapril combination is superior to enalapril monotherapy in delaying time to first occurrence of cardiovascular death or HF hospitalization and (ii) whether aliskiren monotherapy is superior or at least non-inferior to enalapril monotherapy on this endpoint. PerspectiveThe ATMOSPHERE study will definitively determine the role of a DRI strategy additional to or as an alternative to conventional RAAS blockade in patients with chronic systolic HF. ----------------------------------------------------------------------- KeywordsChronic heart failure † Renin -angiotensin † Renin † ACE-inhibitor † Aliskiren

Poorly controlled hypertension is a major risk for cardiovascular morbidity and mortality, strokes, heart failure and renal failure. Despite these devastating complications, blood pressure control of p140/90 mmHg, which is above the current standard, is very poor worldwide, accounting for 34% of hypertensive patients in the United States, and 6% in other countries. The reasons for this poor control of blood pressure include lack of aggressive treatment by physicians, especially for the systolic blood pressure, drug selection and patient compliance. The blood pressure follows a circadian rhythm and is the highest between 0600 to 1200 h, when most complications occur. Long-acting drugs that extend their action to cover this vulnerable period are preferable, especially those that block the renin-angiotensin-aldosterone system, such as ACE inhibitors and angiotensin receptor blockers, and are the most effective in controlling blood pressure and preventing or reducing its cardiovascular and renal complications. With respect to the angiotensin receptor blockers, telmisartan has been demonstrated by several studies to be the longest acting among its class of drugs and to effectively prevent the early morning rise of blood pressure.