The results of trials of vasodilators in patients with chronic heart failure showed improved survival by adding ACE-inhibitors or a combination of isosorbide dinitrate and hydralazine to the usual therapy with digoxin and diuretics. However, the mean prolongation of life is unsatisfactory (10-17 months) and very small effects are observed on the various measures of quality of life. In patients with asymptomatic left ventricular dysfunction, the treatment with ACE-inhibitors reduces the progression to the clinical phase of heart failure but not in all patients. Therefore is attractive to evaluate new agents to improve the results of the present therapeutic strategies. The attempts to combine new vasodilators to regimens including ACE-inhibitors have been inconclusive or even deleterious. The identification of subgroups of patients with different clinical, hemodynamic and neurohormonal characteristics may allow a more appropriate use of the new therapeutic resources.