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

Nakae, Ichiro; Mitsunami, Kenichi; Yoshino, Tomohide; Omura, Tomoko; Tsutamoto, Takayoshi; Matsumoto, Tetsuya; Morikawa, Shigehiro; Inubushi, Toshiro; Horie, Minoru

doi:10.1016/j.cardfail.2010.05.006

« Previous Next »Journal of Cardiac Failure
Volume 16, Issue 10 , Pages 812-822, October 2010

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

Ichiro Nakae, MD
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Shiga, Japan
Kenichi Mitsunami, MD
- Department of Family Medicine, Shiga University of Medical Science, Shiga, Japan
- Reprint requests: Kenichi Mitsunami, MD, Department of Family Medicine, Shiga University of Medical Science, Tsukinowa-cho, Seta, Otsu, Shiga 520-2192, Japan. Tel: +81-77-548-2598; Fax: +81-77-548-9701.
Tomohide Yoshino, MD
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Shiga, Japan
Tomoko Omura, MD
- Omura Clinic, Shiga, Japan
Takayoshi Tsutamoto, MD
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Shiga, Japan
Tetsuya Matsumoto, MD
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Shiga, Japan
Shigehiro Morikawa, MD
- Department of Fundamental Nursing, Morphology & Physiology, Shiga University of Medical Science, Shiga, Japan
Toshiro Inubushi, PhD
- Biomedical MR Science Center, Shiga University of Medical Science, Shiga, Japan
Minoru Horie, MD
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Shiga, Japan

Received 24 November 2009; received in revised form 28 February 2010; accepted 7 May 2010. published online 02 July 2010.

Abstract

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 μmol/g), but higher in ICM (7.59 ± 4.36 μmol/g) than in NML hearts (4.05 ± 1.94 μmol/g). There was no significant difference in TG between DCM (4.84 ± 6.45 μmol/g) and NML. Myocardial CR in HCM (20.4 ± 8.4 μmol/g), DCM (14.8 ± 4.8 μmol/g), and ICM (19.4 ± 6.3 μmol/g) was significantly lower than that in NML hearts (27.1 ± 4.3 μmol/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 TG did not. In DCM, myocardial TG correlated with body mass index, but not with MIBG uptake.

Conclusions

Myocardial TG 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.

Key Words: Proton magnetic resonance spectroscopy, triglyceride, heart failure, cardiomyopathy