The renin-angiotensin-aldosterone system is the main regulator of arterial blood pressure and water-electrolyte homeostasis. We have currently at our disposal more and more evidence indicating the possibility of local renin-angiotensin-aldosterone systems existing in blood vessels, brain, heart or kidneys and regulated independently of the systemic one. One of the essential elements of this system is the enzyme converting angiotensin I (ACE-angiotensin converting enzyme), which is responsible for the synthesis of an active octapeptide - angiotensin II. (Ang II) as well as for degradation of bradykinin to inactive peptides. There seems to be convincing, theoretical, experimental and clinical evidence pointing to potential usefulness of this type of drugs in treatment of coronary heart disease. Inhibition of Ang II formation, both on systemic and tissue level, improves the function of endothelium, stabilizes the atheromatous plaque and reverses pathologic changes in the heart and blood vessels. Varying affinity of different drugs belonging to the ACE inhibitor group to tissue angiotensin-converting enzyme may have a significant effect on the therapeutic efficacy in treatment of patients with coronary heart disease. ACE inhibitors may not only improve the clinical condition of patients with ischemic heart disease, but may also have positive effect on the prognosis.

Keywords: ACE inhibitions, coronary heart disease, prevention