β-Adrenergic Blockade and Myocardial Perfusion in Coronary Artery Disease: Differential Effects in Stenotic Versus Remote Myocardial Segments

Journal of Nuclear Medicine

Christophe A. Wyss¹  Gustav K. von Schulthess¹  Mehdi Namdar¹  Michael Klainguti¹  Thomas F. Lüscher¹  Pascal Koepfli¹  Philipp A. Kaufmann¹ 

关键词: β-adrenergic blockade;    coronary artery disease;    myocardial blood flow;    PET;   

DOI  :  

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

β-Adrenergic blocking agents are widely used in coronary artery disease (CAD), although their impact on myocardial blood flow (MBF) and coronary flow reserve (CFR) remains unclear. We studied the effect of long-term β-blocker treatment (carvedilol or metoprolol) on coronary microcirculation in CAD patients using PET. Methods: Regional and global resting and adenosine-induced hyperemic MBF and CFR were measured with 13N-ammonia and PET in 36 CAD patients before and after 12 wk of oral therapy with either carvedilol, 50 mg/d, or metoprolol, 100 mg/d. Results: β-Blockade decreased global resting MBF in proportion to cardiac work (from 0.86 ± 0.20 to 0.77 ± 0.14 mL/min/g, P < 0.05) without affecting global hyperemic flow. Hyperemic MBF was significantly lower in stenosis-dependent segments than in remote segments (1.76 ± 0.64 vs. 2.04 ± 0.67 mL/min/g, P < 0.05) at baseline but was comparable in both after treatment (2.02 ± 0.68 vs. 1.90 ± 0.78 mL/min/g, P = not statistically significant [NS]), resulting in a significant CFR increase in stenotic segments (+15%, P < 0.05) but not in remote segments (+9%, P = NS). Conclusion: The beneficial effect of β-adrenergic blockade can be explained by the reduction in oxygen consumption (= decreased demand) but also by a modest improvement in vasodilator capacity (= increased supply). The improvement in CFR is found predominantly in stenosis-dependent rather than remote segments.

【 授权许可】

Unknown