Beneficial effects of metoprolol on myocardial sympathetic function: Evidence from a randomized, placebo-controlled study in patients with congestive heart failure

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• 作者：Paul A. R. de Milliano ; Andre C. de Groot ; Jan G. P. Tijssen ; Berthe L. F. van Eck-Smit ; Pieter A. van Zwieten ; Kong I. Lie
• 刊名：American Heart Journal
• 出版年：2002
• 出版时间：August 2002
• 年：2002
• 卷：144
• 期：2
• 页码：E3
• 全文大小：409 K

文摘

Background We sought to investigate whether β-blockers exert a presynaptic effect in the myocardium as measured by ¹²³I-metaiodobenzylguanidine. Methods The study comprised 59 patients with congestive heart failure, New York Heart Association class II or III, and left ventricular ejection fraction <35 % . After an open label titration phase, patients were randomized to their maximal tolerable dose of metoprolol or placebo. Myocardial MIBG uptake was measured before the titration phase and after 6 months of treatment. Other parameters were maximal oxygen consumption, 6-minute walking test, plasma neurohormones, and echocardiographic parameters. Results We found a 21.9 % increase in mean myocardial MIBG uptake after 6 months of treatment with metoprolol. In contrast, MIBG uptake decreased by 7.8 % in the placebo group (P = 0.03 compared with metoprolol). Left ventricular end-diastolic diameter decreased from 74 ± 11 mm to 67 ± 10 mm (P < .05, within-group comparison) and LVEF increased from 25.3 % ± 7.4 % to 32.6 % ± 9.6 % (P < .05, within-group comparison) in the metoprolol group. Placebo-treated patients showed no significant changes. Comparison of changes in left ventricular end-diastolic diameter and LVEF between metoprolol and placebo did not reach statistical significance (P = 0.2). Conclusions This randomized, placebo-controlled study demonstrates that metoprolol has a presynaptic effect as measured by myocardial MIBG scintigraphy in both ischemic and nonischemic cardiomyopathy. (Am Heart J 2002;144:e3.)