The new beta-
adrenoceptor partial agonist
cicloprolol acts as a beta-agonist at normal levels and as a beta-antagonist at high levels of
adrenergic discharge. Treatment with
cicloprolol should protect the heart against excessive stimulation, while providing a baseline level of sympathetic drive. The clinical interest of such a profile is, however, not yet established in
heart failure. Accordingly this study examined the safety of oral
cicloprolol, a step necessary before undertaking efficacy comparison with other compounds recently proposed to treat
heart failure. Twenty-five patients were studied.
Cicloprolol was given once a day for 2 weeks in a crossover double-blind placebo-controlled design. Follow-ups were obtained at baseline and at the end of each period. At baseline all patients had clear evidence of
heart failure.
Cicloprolol did not affect resting heart rate and blood pressure, but it reduced significantly peak exercise heart rate and peak rate-pressure product. The effect was especially significant in patients with sinus rhythm. The
drug did not induce
bradycardia or arrhythmias. Resting and exercise ejection rate were not affected.
Cicloprolol improved the quality of life and the work capacity of 5 of 12 patients with congestive failure due to ischemic etiology. Side effects were few and similar with placebo and
cicloprolol. Thus, short-term administration of
cicloprolol is safe in moderate
heart failure.