Sacubitril and valsartan combination is used to treat chronic heart failure in adults to help reduce the risk of death and hospitalization. This medicine is also used to treat children with symptomatic heart failure. Valsartan is an angiotensin II receptor blocker (ARB). It works by blocking a substance in the body that causes blood vessels to tighten. As a result, valsartan relaxes the blood vessels. This lowers blood pressure and increases the supply of blood and oxygen to the heart.