Copyright © 1990 by the European Society of Cardiology.
© 1990 The European Society of Cardiology
Clinical experience of therapy with xamoterol in patients with severe systolic and diastolic dysfunction
Cardiac Catheterization and Interventional Cardiology Unit, Division of Cardiology and Department of Physiology, University of Louvain Brussels, Belgium
Address for correspondence: Dr H. Pouleur, University of Louvain, School of Medicine, Avenue Hippocrate 55, Box 5560, B-l200 Brussels, Belgium
Xamoterol (‘Corwin’, ‘Carwin’, ‘Corwil’, ‘Xamtol’, ICI118, 587), a partial β-agonist, has beneficial effects in patients with mild to moderate heart failure.
In acute haemodynamic studies in more severe heart failure some patients have shown negative inotropic and chronotropic effects, although treatment with a partial agonist should protect the heart against excessive stimulation, while providing a baseline level of sympathetic drive. This study examined the effects of oral xamoterol in patients with moderate to severe heart failure.
Ten patients were studied, nine with ischaemic heart disease. All but one were in New York Heart Association (NYHA) functional Class III. Other treatment, including angiotensin converting enzyme (ACE) inhibitors, was continued. The patients underwent a standard bicycle exercise test, and the following day cardiac catheterization was performed to obtain measurements of ventricular size (by cineangiography) and pressures during the cardiac cycle. The patients began treatment with xamoterol 200 mg b.d. in addition to their baseline therapy, and this was continued for an average of 9 weeks, after which the exercise test and the haemodynamic investigations were repeated.
At baseline, all patients had a raised left ventricular end-diastolic pressure (LVEDP) and nine had a low election fraction, raised end-systolic and end-diastolic volume indices and reduced left ventricular (+) dP/dtmax Xamoterol produced a marked reduction in left ventricular filling pressure, a fall in end-systolic volume index and improvements in T1, (+) dP/dtmax and (dP/dt)/DP40 with no change in mean aortic pressure. Duration of exercise increased in four patients, and did not change in the other four tested. Xamoterol did not affect resting heart rate but reduced the rate on exercise and the degree of ST segment depression. Nine of the ten patients felt better on treatment in terms of fatigue and dyspnoea.
In this study, oral xamoterol improved clinical and haemodynamic status in patients with moderately severe heart failure without producing serious side-effect.
Key Words: Congestive heart failure • xamoterol • ACE inhibitors