Does Angiotensin Converting Enzyme Inhibitor Protect the Heart in Cardiac Surgery? From Laboratory to Operating Room: Clinical Application of Experimental Study

Abstract

Animal studies have shown angiotensin converting enzyme (ACE) inhibitors to be effective agents for myocardial protection. They protect against lethal arrhythmias, preserve ventricular function, improve coronary reserve (especially after ischemia/reperfusion), and reverse myocardial hypertrophy. Human studies, on the other hand, have shown inconsistent results. The beneficial effects of ACE inhibitors demonstrated in animal studies provide major advantages for cardiac surgery. First, most cardiac surgery is performed under ischemic arrest induced by a cardioplegic solution, and the protective effects of ACE inhibition against reperfusion injury can reduce peri-operative mortality and morbidity. Second, most patients who undergo such surgery have myocardial hypertrophy due to hypertension, pressure or volume overload mediated by valve disease, or myocardial infarction. Ventricular hypertrophy is a strong risk factor for sudden death, probably from arrhythmia. Regression of the hypertrophy may prevent post-operative sudden death, thereby allowing for long-term benefits of surgery. In this paper, I review ACE inhibitor studies in animals and humans and the protective mechanisms involved. I also discuss why human studies show inconsistent results in spite of the fact that ACE inhibition is consistently protective in animal studies. Finally, I explore the potential clinical applications of ACE inhibitors in cardiac surgery.

Patterns of Use of Perioperative Angiotensin-Converting Enzyme Inhibitors in Coronary Artery Bypass Graft Surgery With Cardiopulmonary Bypass

“…12,39 Thus, inhibition of ACE can mitigate angiotensin production and, importantly, may improve microcirculatory perfusion via the aforementioned mechanisms. 40,41 Additionally, ACEI added to cardioplegia solution has been shown to directly reduce ischemia/reperfusion injury, to reduce myocardial ACE activity, and to provide antiarrhythmic effects. 40 …”

“…40,41 Additionally, ACEI added to cardioplegia solution has been shown to directly reduce ischemia/reperfusion injury, to reduce myocardial ACE activity, and to provide antiarrhythmic effects. 40 …”

Efeitos das cardioplegias sangüínea e cristalóide no miocárdio hipertrófico de coelho: avaliação estrutural e ultra-estrutural

“…During proliferation and cellular regeneration many ribosomes are required to synthesize proteic masses for cytoplasmatic expansion. Thus, during the reaction of cells to injury, ribosomes produce defense and repair enzymes for cell survival [22,23]. However, the marked presence of nucleoli in all cells analysed in Group I and Group II is due to the activation of nucleolar metabolic mechanisms that lead to cell protection.…”