使用对比增强磁共振成像来识别可逆性心肌功能障碍。

The use of contrast-enhanced magnetic resonance imaging to identify reversible myocardial dysfunction.

作者信息

Kim R J, Wu E, Rafael A, Chen E L, Parker M A, Simonetti O, Klocke F J, Bonow R O, Judd R M

机构信息

Feinberg Cardiovascular Research Institute, and Department of Medicine, Northwestern University Medical School, Chicago, IL 60611-3008, USA.

出版信息

N Engl J Med. 2000 Nov 16;343(20):1445-53. doi: 10.1056/NEJM200011163432003.

DOI:10.1056/NEJM200011163432003

PMID:11078769

Abstract

BACKGROUND

Recent studies indicate that magnetic resonance imaging (MRI) after the administration of contrast material can be used to distinguish between reversible and irreversible myocardial ischemic injury regardless of the extent of wall motion or the age of the infarct. We hypothesized that the results of contrast-enhanced MRI can be used to predict whether regions of abnormal ventricular contraction will improve after revascularization in patients with coronary artery disease.

METHODS

Gadolinium-enhanced MRI was performed in 50 patients with ventricular dysfunction before they underwent surgical or percutaneous revascularization. The transmural extent of hyperenhanced regions was postulated to represent the transmural extent of nonviable myocardium. The extent of regional contractility at the same locations was determined by cine MRI before and after revascularization in 41 patients.

RESULTS

Contrast-enhanced MRI showed hyperenhancement of myocardial tissue in 40 of 50 patients before revascularization. In all patients with hyperenhancement the difference in image intensity between hyperenhanced regions and regions without hyperenhancement was more than 6 SD. Before revascularization, 804 of the 2093 myocardial segments analyzed (38 percent) had abnormal contractility, and 694 segments (33 percent) had some areas of hyperenhancement. In an analysis of all 804 dysfunctional segments, the likelihood of improvement in regional contractility after revascularization decreased progressively as the transmural extent of hyperenhancement before revascularization increased (P<0.001). For instance, contractility increased in 256 of 329 segments (78 percent) with no hyperenhancement before revascularization, but in only 1 of 58 segments with hyperenhancement of more than 75 percent of tissue. The percentage of the left ventricle that was both dysfunctional and not hyperenhanced before revascularization was strongly related to the degree of improvement in the global mean wall-motion score (P<0.001) and the ejection fraction (P<0.001) after revascularization.

CONCLUSIONS

Reversible myocardial dysfunction can be identified by contrast-enhanced MRI before coronary revascularization.

摘要

背景

近期研究表明，注射造影剂后的磁共振成像（MRI）可用于区分可逆性和不可逆性心肌缺血损伤，而不论室壁运动程度或梗死时间长短。我们推测，对比增强MRI的结果可用于预测冠心病患者血运重建后心室异常收缩区域是否会改善。

方法

对50例心室功能不全患者在接受外科或经皮血运重建术前进行钆增强MRI检查。假设强化区域的透壁范围代表无存活心肌的透壁范围。对41例患者在血运重建前后通过电影MRI测定相同部位的局部收缩力。

结果

血运重建术前，50例患者中有40例心肌组织出现强化。在所有强化患者中，强化区域与未强化区域之间的图像强度差异超过6个标准差。血运重建术前，在分析的2093个心肌节段中，804个（38%）有异常收缩力，694个节段（33%）有一些强化区域。在对所有804个功能不全节段的分析中，血运重建后局部收缩力改善的可能性随着血运重建术前强化的透壁范围增加而逐渐降低（P<0.001）。例如，血运重建术前无强化的329个节段中有256个（78%）收缩力增加，但组织强化超过75%的58个节段中只有1个收缩力增加。血运重建术前左心室功能不全且未强化的比例与血运重建后整体平均室壁运动评分（P<0.001）和射血分数（P<0.001）的改善程度密切相关。