New trends in the use of angiotensin converting enzyme inhibitors in chronic heart failure.

Although the underlying pathophysiology in most patients with congestive heart failure is impaired myocardial contractility, hemodynamic and clinical benefit can be achieved by treatment with agents that alter the loading conditions of the left ventricle. This was initially accomplished with direct-acting vasodilators such as sodium nitroprusside, nitrates, and hydralazine. Subsequently, the angiotensin converting enzyme (ACE) inhibitors have been demonstrated to produce similar short-term hemodynamic improvement and have generally proved superior in their long-term hemodynamic and clinical efficacy. Although the ACE inhibitors were initially employed as adjunctive treatment in patients with refractory heart failure, recent studies indicate that they are also effective in patients with mild and moderate symptoms and that they are at least as effective as digitalis in this patient group. Furthermore, a growing body of data indicates that the ACE inhibitors improve the survival rate in patients with severe and, possibly, milder heart failure. As a result, the ACE inhibitors have emerged as useful agents in patients with mild symptoms and are being investigated for their potential to improve the survival rate and prevent clinical deterioration in patients with asymptomatic or minimally symptomatic left ventricular dysfunction.