The Effects of Intravenous Carvedilol, A New Multiple Action Vasodilatory β-Blocker, in Congestive Heart Failure

Abstract

Recent studies have shown that beta-blockers may be effective in the management of heart failure. However, negative inotropic effects of these agents may offset the beneficial properties of up-regulation of the beta-receptors and reduction in myocardial oxygen demand. Carvedilol is a new drug which possesses a balanced combination of vasodilatation and beta-blockade. Previous studies have shown that carvedilol may have beneficial effects on left ventricular function in patients with ischemic heart disease. We have performed a preliminary study to address the safety and acute effects of intravenous carvedilol in 17 patients with chronic congestive heart failure secondary to ischemic heart disease. Acute hemodynamic changes were monitored by right heart catheterization and arterial cannulation. Ejection fraction was also monitored by radionuclide ventriculography. Significant reductions in heart rate (79 +/- 14 to 72 +/- 12 beats/min, p less than 0.001) systolic and diastolic blood pressure (137 +/- 20/72 +/- 8 to 119 +/- 19/66 +/- 8 mm Hg, p less than 0.001 and p less than 0.01), systemic vascular resistance (1766 +/- 367 to 1518 +/- 377 dynes/s/cm-5/m2, p less than 0.001) and pulmonary artery wedge pressure (20 +/- 8 to 15 +/- 7 mm Hg, p less than 0.001) were observed. Ejection fraction increased significantly from 24 to 28% (p less than 0.001) but there was little change in cardiac index or stroke volume index. The peak changes occurred at 10 min and the effect on pulmonary wedge pressure was maintained up to 30 min. No adverse effects were noted. The improvements in left ventricular filling pressure and systolic function, and the reduction in sympathetic activity may combine to produce an important therapeutic advantage in congestive heart failure. Further studies with this interesting agent are recommended.