A randomized double-blind crossover trial included 16 patients with severe congestive heart failure who received isosorbide dinitrate or placebo for eight weeks, and then the opposite treatment for eight more weeks. All patients received their usual maintenance therapy with digitalis and diuretics. Seven morbid events occurred during 85 patient-weeks of isosorbide dinitrate therapy compared with 17 during 76 patient-weeks of placebo. Severity of congestive heart failure improved in all eight patients who received isosorbide dinitrate compared with two patients who showed improvement and five whose symptoms became worse with placebo. No significant differences in physical findings, cardiac dimensions, or resting hemodynamics were observed. Maximal exercise duration increased significantly by 2.54 minutes with isosorbide dinitrate therapy, and rose insignificantly by 1.24 minutes with placebo. This preliminary trial suggests that long-term vasodilator therapy may be clinically beneficial in congestive heart failure.
(JAMA 240:443-446, 1978)