Regional reduction in myocardial glucose utilization predicts cardiac events in dilated cardiomyopathy

To examine the relationship between myocardial glucose utilization and the occurrence of life-threatening cardiac events (CE) in patients with idiopathic dilated cardiomyopathy (DCM), we performed positron emission tomography (PET) using F-18 fluoro-2-deoxyglucose (FDG) in 10 DCM patients. Glucose-loading (75 g per os) FDG-PET was assessed quantitatively using Standardized Uptake Value (SUV). Myocardial blood flow (MBF) at rest was also assessed by N-13 ammonia (NH3)-PET. For image analysis, two short axial slices (base and midventricular) were divided into eight segments, and we obtained regional MBF (rMBF) and regional FDG-SUV (rSUV) in each segments. Furthermore, we investigated maximum (Max), minimum (Min), average (Ave) value of rSUV and regional F/M ratio (rSUV/rMBF) in each subject. All patients were treated with the usual regimen and observed at least 17 months after the PET study Four out of 10 patients had CE during observation period while none showed reduced rMBF(mean 0.70 +/-: 0.19 ml/min/g). Min SUV (4.34 +/- 0.59 vs. 5.76 +/- 0.77, p = 0.01), Min F/M (5.31 +/- 1.14 vs. 9.36 +/- 2.45, p = 0.02) and Ave F/M (7.92 +/- 1.96 vs. 12.56 +/- 3.62, p = 0.05) were significantly lower in patients with CE than in others. while Max SUV and Ave SUV were not different between the patients with and without CE. Our data indicate that the presence of regional reduction in capacity of myocardial glucose utilization predicts cardiac events in DCM patients, while average SUV does not.