Blockade of Renin Angiotensin System in Heart Failure Post-Myocardial Infarction: What is the Best Therapy?

Heart Failure (HF) is a progressive and fatal disorder, which ranks among the major public health problems in Brazil and worldwide. However, survival for patients who developed the syndrome after myocardial infarction (MI) enhanced significantly, as a result of an improvement of pharmacological therapies. A medical breakthrough was the discovery that remodelling of the left ventricle (LV) may be limited by the blockade of the renin-angiotensin system (RAS), at the level of angiotensin converting enzyme (ACE) and binding of angiotensin (Ang) II to its AT1 receptor. This review shows that the therapeutic effects of both ACE inhibitors and the angiotensin receptor blockers (ARB) go beyond the interference in the biochemical pathway ACE-Ang II AT1-receptor. Such effects are also related to the potentiation of bradykinin and increased beneficial effects mediated by the AT2 receptor. Therefore, the results of five randomized trials were presented, which evaluated the use of losartan, valsartan or candesartan, considering their effects on survival and risk of clinical deterioration in patients with symptomatic HF after MI. These studies confirmed the advantage of ARBs over inhibitors in case of cough, rashes and angioneurotic edema, despite similar adverse effects, such as hyperkalemia, renal failure and hypotension. Thus, in this article we have discussed with patents that ACE inhibitors also appear as the first option as RAS inhibitors in search of relevant results for the patient, allowing the alternative use of ARBs to those patients with intolerance.