Angiotensin-converting enzyme inhibitors (ACEi) have been a cornerstone treatment for patients with heart failure and reduced ejection fraction (HFrEF) for over 25 years. They are included in every major set of guidelines for HFrEF management. Angiotensin receptor blockers (ARB's, such as valsartan) have similarly been shown to decrease the mortality rate of patients with HFrEF for patients who are unable to tolerate ACEi therapy.