Cine-MRI and 31P-MRS for evaluation of myocardial energy metabolism and function following coronary artery bypass graft

Zhang, Zhuoli; Li, Junxia; Wu, Shengyong; Liu, Ying; Fan, Zhaoyang; Zhou, Xiangzhi; Zhao, Haitao; Li, Debiao; Huan, Yi

doi:10.1016/j.mri.2010.03.040

« Previous Next »Magnetic Resonance Imaging
Volume 28, Issue 7 , Pages 936-942, September 2010

Cine-MRI and ³¹P-MRS for evaluation of myocardial energy metabolism and function following coronary artery bypass graft

Zhuoli Zhang
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, People's Republic of China
- Department of Radiology, Northwestern University, Chicago, IL 60611, USA
- With equal contribution: Zhuoli Zhang, MD, PhD; Junxia Li, MD, PhD.
Junxia Li
- Department of Cardiology, Bethune International Peace Hospital, Shijiazhuang 050082, People's Republic of China
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, People's Republic of China
- With equal contribution: Zhuoli Zhang, MD, PhD; Junxia Li, MD, PhD.
Shengyong Wu
- Department of Radiology, First Central Hospital of Tianjin Medical University, Tianjin 300171, People's Republic of China
Ying Liu
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, People's Republic of China
Zhaoyang Fan
- Department of Radiology, Northwestern University, Chicago, IL 60611, USA
Xiangzhi Zhou
- Department of Radiology, Northwestern University, Chicago, IL 60611, USA
Haitao Zhao
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, People's Republic of China
Debiao Li
- Department of Radiology, Northwestern University, Chicago, IL 60611, USA
Yi Huan
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, People's Republic of China
- Corresponding author. Tel.: +86 29 84775421; fax: +86 29 84775421.

Received 19 March 2009; received in revised form 16 March 2010; accepted 17 March 2010. published online 05 May 2010.

Abstract

Previous studies investigated the effect of successful coronary artery bypass grafting (CABG) upon left ventricular function. The relationship between myocardial metabolism and heart function after CABG remains unclear. We investigated the relationship between high-energy phosphate (HEP) and cardiac function following CABG using cine magnetic resonance imaging (cine-MRI) and phosphorus-31 magnetic resonance spectroscopy (³¹P-MRS). A retrospective study was approved by the institutional review board. MRI and ³¹P-MRS examinations were reviewed of 37 patients with multivessel disease who underwent CABG. 13 of these patients selected for the retrospective analysis had ≥70% stenosis in the proximal left anterior descending artery (LAD) and left ventricular ejection fraction (LVEF) <40%. LVEF was evaluated using cine-MRI. HEP such as phosphocreatine (PCr) and adenosine triphosphate (β-ATP) was measured using ³¹P-MRS to calculate PCr/β-ATP ratio. Cine-MRI and ³¹P-MRS measurements were performed before and after CABG, respectively. Ten normal healthy volunteers served as controls. ³¹P-MRS in 13 patients showed that post-CABG PCr/β-ATP ratio was significantly higher than that of pre-CABG (pre-CABG vs. post-CABG, 1.43±0.24 vs. 1.71±0.29, P<.05), but both ratios were significantly lower than control group (2.13±0.21, P<.05). With the change of the ratio, the left ventricle function was significantly improved (LVEF: pre-CABG vs. post-CABG: 35.7±12.9 vs. 45.6±17.2, P<.05).

The ability of ³¹P-MRS and cine-MRI to non-invasively assess changes of metabolism and function in myocardium may prove important for patient-specific optimization of treatment strategies.

Keywords: Phosphorus-31 magnetic resonance spectroscopy, Cine magnetic resonance imaging, High-energy phosphate, Heart function, Coronary artery bypass grafting surgery