Reduction of myocardial oxidative metabolism in dilated cardiomyopathy but not in remote areas in myocardial infarction

We performed PET with carbon-11 acetate in patients with LV dysfunction in order to assess alterations in myocardial metabolism in apparently well-perfused myocardium in patients with dilated cardiomyopathy (DCM) and myocardial infarction (MI). We studied 15 patients with DCM 4and 16 patients with MI. The clearance rate constant for carbon-11 acetate derived from monoexponential fitting (Kmono) was measured as a marker of myocardial oxidative metabolism. We also performed PET in 10 normal subjects as control. Kmono was significantly lower in patients with DCM than in the control subjects (0.049 +/- 0.008 vs. 0.060 +/- 0.010 /min; P < 0.01). In contrast, Kmono in the remote areas in patients with MI was preserved (0.061 +/- 0.013), while Kmono in the infarcted areas (0.036 +/- 0.010) was significantly lower than that in the controls (P < 0.001). These data suggest that myocardial oxidative metabolism is preserved in remote area in patients with MI, despite LV remodeling, while it is decreased in patients with DCM. The reduction in oxidative metabolism may be one of the causes of LV dysfunction in patients with DCM but not in patients with MI. (C) 2004 Elsevier B.V. All rights reserved.