Impairment of Subendocardial Perfusion Reserve and Oxidative Metabolism in Nonischemic Dilated Cardiomyopathy

Abstract Background Cardiac magnetic resonance (CMR) and [11 C]acetate positron emission tomography (PET) were used to assess the hypothesis that patients with nonischemic dilated cardiomyopathy (NIDCM) have decreased subendocardial perfusion reserve and impaired oxidative metabolism, consistent with the concept of “energy starvation” in heart failure (HF). Methods and Results CMR myocardial perfusion was evaluated in 13 NIDCM patients and 15 control subjects with coronary risk factors and normal myocardial perfusion. The NIDCM patients underwent [11 C]acetate PET. The myocardial perfusion index (MPI) was calculated as the normalized rate of myocardial signal augmentation following gadolinium contrast injection. Hyperemic transmural, subendocardial, and subepicardial MPI were reduced in NIDCM compared with control subjects [0.13 vs 0.18 ( P