Assessing the treatment of congestive heart failure: inotropic agents and calcium channel blockers

Abstract

Despite recent evidence that angiotensin-converting enzyme (ACE) inhibitors reduce mortality in patients with congestive heart failure (CHF), it is important to note that roughly 40% of patients with New York Heart Association class I-III disease treated with these agents died during 4-year follow-up in the treatment arm of two large trials. Given this high mortality rate, there is an obvious need for therapy beyond digoxin, diuretics, and ACE inhibitors. Digoxin is associated with favorable effects on exercise capacity, ejection fraction, and clinical symptomatology in the majority of patients with CHF. Its effects on mortality are unknown, but are the subject of a continuing trial sponsored by the National Institutes of Health. The beta-agonists are also associated with hemodynamic and clinical improvements in patients with CHF, but probably increase the risk of mortality, especially when taken on a long-term basis. Therefore, their use should be limited to the short-term management of acute exacerbations of CHF. Phosphodiesterase inhibitors, particularly milrinone, are associated with increased mortality in patients with CHF, apparently related to their arrhythmogenic effect. Little evidence exists that calcium channel blockers exert beneficial effects in patients with CHF (unlike their role in hypertrophic cardiomyopathy); indeed, first-generation calcium channel blockers may be detrimental in patients with left ventricular dysfunction and they should generally be avoided in this setting. Treatment of ischemia in patients with CHF should be initiated with nitrates; low dosages of vasoselective dihydropyridine calcium channel blockers may be attempted if nitrates fail.