Myocardial Free Fatty Acid and Glucose Use After Carvedilol Treatment in Patients With Congestive Heart Failure

Background—Use of β-adrenoreceptor blockade in the treatment of heart failure has been associated with a reduction in myocardial oxygen consumption and an improvement in myocardial energy efficiency. One potential mechanism for this beneficial effect is a shift in myocardial substrate use from increased free fatty acid (FFA) oxidation to increased glucose oxidation. Methods and Results—We studied the effect of carvedilol therapy on myocardial FFA and glucose use in 9 patients with stable New York Heart Association functional class III ischemic cardiomyopathy (left ventricular ejection fraction ≤35%) using myocardial positron emission tomography studies and resting echocardiograms before and 3 months after carvedilol treatment. Myocardial uptake of the novel long chain fatty acid metabolic tracer 14(R, S)-[18F]fluoro-6-thia-heptadecanoic acid ([18F]-FTHA) was used to determine myocardial FFA use, and [18F]fluoro-2-deoxy-glucose ([18F]-FDG) was used to determine myocardial glucose use. After carvedilol trea...