Comparative evaluation of isosorbide-5-mononitrate and nitroglycerin in chronic congestive heart failure

The hemodynamic effects of isosorbide-5-mononitrate (IS-5-MN) and nitroglycerin were compared in 10 patients with chronic congestive heart failure (CHF). Both drugs were given intravenously, at an infusion rate individually titrated to achieve a maximal increase in cardiac output and a maximal decrease in pulmonary capillary wedge pressure. Both drugs produced the typical hemodynamic responses to nitrates, the most prominent of which were decreases in pulmonary capillary wedge, pulmonary arterial and right atrial pressures, and an increase in cardiac output. Several differences in the response to these 2 drugs were observed. Pulmonary capillary wedge pressure was reduced from 31.5 +/- 3.0 to 19.6 +/- 5.0 mm Hg with nitroglycerin and to 15.0 +/- 3.12 mm Hg with IS-5-MN. Both the absolute and the percent decrease with IS-5-MN were significantly greater (p less than 0.05) than those observed with nitroglycerin. Mean systemic arterial pressure was reduced from 89.2 +/- 11.3 to 79.8 +/- 10.8 with IS-5-MN (difference not significant) and to 67.5 +/- 7.7 mm Hg with nitroglycerin (p less than 0.01). The difference, both in absolute and percent reductions, was statistically significant. Thus, in patients with chronic CHF, IS-5-MN produced a greater decrease in pulmonary capillary wedge pressure (the major beneficial effect of nitrates in this condition) and a smaller decrease in systemic arterial pressure (the potentially deleterious effects of nitrates). These findings indicate a potential advantage of IS-5-MN over nitroglycerin in patients with CHF, particularly in those with CHF of ischemic etiology.