[Beta receptor blockers in dilated cardiomyopathy (clinical aspects)]

Results of 16 international published studies (with a total of 397 patients in NYHA-classes II-III) concerning chronic therapy with beta-adrenoceptor blockade in idiopathic dilated cardiomyopathy were analyzed. 8 studies were placebo controlled. Under beta-blockade cardiac output increased significantly by about 15% and ejection fraction by approximately 30%, apparently due to an improvement in contractility and relaxation of LV myocardium. Therapy was tolerated without complications in 93% of patients when the loading dose was 5 to 15 mg metoprolol/d (or equivalent) and a long-term dose of 100-200 mg/d metropolol (or equivalent) was reached within 4 weeks. Patients with severe heart failure (NYHA IV) had a higher risk of complications. A positive effect of beta-blockade in IDC was achieved in most cases but not earlier than after 2-3 months after initiating therapy. Despite these positive results beta-blockade in patients with IDC may not yet be recommended generally. Sufficient results of controlled trials are still lacking. Important questions with regard to the prognosis under beta-blockade, to the effects of cardioselectivity and intrinsic activity, and to the efficacy of this kind of therapy in the presence of ACE inhibitors have not been answered. Thus, major trials with controlled design are needed.