Xamoterol in mild to moderate heart failure: a subgroup analysis of patients with cardiomegaly but no concomitant angina pectoris.

Xamoterol has been shown in large, double-blind studies to produce benefit in patients with heart failure. Ischaemic heart disease is the commonest cause of heart failure in the Western World and many patients with heart failure also have angina pectoris (Califf et al., 1982). In view of the known anti-ischaemic effects of xamoterol, we analysed the results of a subgroup of 269 patients with heart failure but without chest pain as a limiting factor on exercise to compare the efficacy of xamoterol in such patients with that of the total group. There were no differences in exercise heart rate, exercise tolerance and symptoms in patients without chest pain compared with the total group. Xamoterol is probably, therefore, acting through myocardial mechanisms other than an anti-ischaemic effect.