When and how to use angiotensin-converting enzyme inhibition in congestive heart failure

Abstract

Angiotensin-converting enzyme (ACE) inhibitors have been found effective in the treatment of congestive heart failure (CHF) and have been recommended as the first choice of vasodilator therapy by some observers. Favorable hemodynamic responses, apparent both at rest and during exercise, result from a considerable reduction in both systemic and pulmonary vascular resistance, apparently due to both the arterial and venodilating effects of these agents. In addition, the recently reported results of the Cooperative North Scandinavian Enalapril Survival Study demonstrate that ACE inhibitors reduce mortality rates in patients with CHF. The etiology of heart failure does not seem to predict clinical response to ACE inhibitors, nor do acute resting and exercise hemodynamic responses. A weak relation has been found between plasma renin activity and short-term hemodynamic and clinical responses, but this association is not evident over the long term. Therefore, a trial of therapy with ACE inhibitors is necessary to judge efficacy in an individual patient with advanced CHF symptoms. Two such agents--captopril and enalapril--are available. The former has a more rapid onset and shorter duration of action, whereas the latter may be given on a twice-daily basis, simplifying chronic therapy.