Noninvasive Evaluation Of The Cardiovascular Effects Of Nebivolol In Cardiac-Failure

The results of several studies, mostly without controls, have suggested that betablockers, administered at progressively increasing doses, may be beneficial in cardiac failure. Based on this hypothesis, betablockers with a peripheral vasodilator effect, such as Nebivolol, could be particularly valuable in this indication. A preliminary study of its tolerance, haemodynamic and neurohormonal effects was carried out with a noninvasive methodology in 12 patients with cardiac failure in sinus rhythm, 8 men and 4 women (average age 53 +/- 12 years), all of whom had Class III or IV symptoms according to the NYHA Classification. The protocol had 2 phases : the first was an open phase during which Nebivolol was administered at a dose of 1 mg/day for 48 hours then 2.5 mg/day for 72 h. In the second phase, the patients were randomly separated into 2 groups, one to receive placebo and the other 2.5 mg for one week then 5 mg of Nebivolol for the 5 remaining weeks.The heart rate decreased significantly from 70 +/- 3 to 63 +/- 4 beats/mn (p < 0.01) with Nebivolol 1 mg/day without further slowing at the 2.5 mg dosage. During the randomised phase, the heart rate remained stable in the Nebivolol group but increased to its initial value in the group given placebo. No aggravation of symptoms was observed in the Nebivolol group. No significant changes in cardiac output, parameters of cardiac loading or contractility could be demonstrated after 6 weeks' treatment.During submaximal exercise testing, plasma concentrations of catecholamines and atrial natriuretic factor tended to be higher with Nebivolol than with placebo. The long-term outcome of these parameters and the beneficial effects of Nebivolol on symptoms and prognosis require further study in a larger number of patients.