Clinical Features of Myocardial Triglyceride in Different Types of Cardiomyopathy Assessed by Proton Magnetic Resonance Spectroscopy: Comparison With Myocardial Creatine

作者：Nakae Ichiro; Mitsunami Kenichi^*; Yoshino Tomohide; Omura Tomoko; Tsutamoto Takayoshi; Matsumoto Tetsuya; Morikawa Shigehiro; Inubushi Toshiro; Horie Minoru

来源：Journal of Cardiac Failure, 2010, 16(10): 812-822.

DOI：10.1016/j.cardfail.2010.05.006

• Proton magnetic resonance spectroscopy
• triglyceride
• heart failure
• cardiomyopathy

Background: Myocardial lipid overstorage may produce cardiomyopathy, leading to dysfunction, but advanced heart failure may cause lipolysis via sympathetic nerve activation. In the failing heart, the creatine kinase system may also be impaired. The aims of this study were to assess myocardial triglyceride (TG) and creatine (CR) in different types of cardiomyopathy and to investigate whether they are related to the severity of cardiac dysfunction.
Methods and Results: In patients with hypertrophic cardiomyopathy (HCM, n = 8), dilated cardiomyopathy (DCM, n = 12) or ischemic cardiomyopathy (ICM n = 10), and normal subjects (NML, n = 22), myocardial TG and CR were evaluated using proton magnetic resonance spectroscopy. To assess cardiac sympathetic nerve activity, myocardial MIBG (a radioactive guanethidine analog) uptake was measured in DCM. Myocardial TG was significantly lower in hypertrophic cardiomyopathy (HCM) (1.92 +/- 0.99 mu mol/g). but higher in ICM (7.59 +/- 4.36 mu mol/g) than in NML hearts (4.05 +/- 1.94 mu mol/g). There was no significant difference in TO between DCM (4.84 +/- 6.45 mu mol/g) and NML. Myocardial CR in HCM (20.4 +/- 8.4 mu mol/g), DCM (14.8 +/- 4.8 mu mol/g), and ICM (19.4 +/- 6.3 mu mol/g) was significantly lower than that in NML hearts (27.1 +/- 4.3 mu mol/g). Overall, myocardial CR correlated positively with the severity of heart failure estimated by ejection fraction or myocardial BMIPP (a radioactive fatty acid analog) uptake, but TO did not. In DCM, myocardial TO correlated with body mass index, but not with MIBG uptake.
Conclusions: Myocardial TO may be related to the specific cause of disease rather than the severity of cardiac dysfunction. In contrast, myocardial CR reflects the severity of heart failure despite different pathoetiologic mechanisms of dysfunction. In DCM, myocardial TG may be affected by an overweight state rather than cardiac sympathetic nerve dysfunction. Thus, myocardial CR has a closer relationship to heart failure severity than does myocardial TG. (J Cardiac Fail 2010;16:812-822)

• 出版日期2010-10