Ordinarily, the level of salt, and therefore free water in the body is controlled very carefully by the kidneys filtration system. This, in turn, is under the governance of the renin, angiotensin, aldosterone axis. In heart failure, there is an abnormal set point of this axis, so the body attempts vigorously to retain fluid and sodium to maintain the forward cardiac output. This can go too far and have deleterious effects. The most sensitive part of this feedback system is the relationship of the angiotensin converting enzyme (ACE), which converts angiotensin I, to angiotensin II under the control of renin. The ACE inhibitors very strongly inhibit this pathway and have been proven in many large clinical trials, to be beneficial in all types of heart failure from mild to severe, both in terms of the patients symptoms and moreover, in terms of the patient’s longevity.
Vascular risk reduction
Renal protection in Diabetes Mellitus