Effect of a new beta-blocker, nipradilol, on cardiac function and neurohumoral factors in idiopathic dilated cardiomyopathy.

This study investigated the therapeutic efficacy of a new beta-blocker, nipradilol, a non-selective agent with vasodilating activity, for the treatment of idiopathic dilated cardiomyopathy (DCM). The New York Heart Association functional class improved in the nipradilol group (n = 9, p < 0.01), but not in the control group who received conventional therapy (n = 9). The observation period was 19 +/- 7 months in the nipradilol group, and 20 +/- 9 months in the control group. Before therapy there was no difference in heart rate between the 2 groups (76 +/- 12 vs 79 +/- 15 beats/min). The end-diastolic and end-systolic left ventricular dimensions decreased in the nipradilol group (p < 0.05), but not in the control group. Radionuclide ventriculography revealed that the left ventricular ejection fraction increased in the nipradilol group (27 +/- 8 to 41 +/- 18%, p < 0.05), but not in the control group (27 +/- 11 to 27 +/- 8%). Plasma norepinephrine tended to be lowered, although not significantly, whereas plasma alpha atrial natriuretic peptide significantly decreased after the therapy (p < 0.01) in the treatment group. Lymphocyte beta-adrenoceptors were up-regulated in the nipradilol group (p < 0.05). None of these parameters changed during the observation period in the control group. Thus, nipradilol improved symptoms and cardiac function with a favorable effect on neurohumoral factors in patients with DCM.