It is also interesting to note that, in the earlier trials, the benefits of beta-blockers were restricted to patients with idiopathic dilated cardiomyopathy (IDCM) as the etiology of heart failure rather than heart failure of ischemic origin. In a 12-week trial of 50 patients (all with EFsless than 40%) randomly assigned to bucindolol or placebo, only those whose heart failure was of idiopathic origin demonstrated benefit. buy flovent inhaler
Compared with patients with heart failure secondary to ischemic heart disease, those with idiopathic cardiomyopathy had significant improvements in hemodynamics, noradrenaline levels, heart failure symptoms and functional class. It has been suggested that patients with idiopathic cardiomyopathy have a greater degree ofbeta-receptor down-regulation and, therefore, respond to beta-blocker therapy, which restores the receptor densities. In contrast, patients with ischemic heart disease demonstrate beta-receptor uncoupling, with decreased response to pharmacological modulation of the beta-receptor. Regardless of the mechanism of the difference in response between these patients, these early findings have also been supported by more recent studies.