杜氏肌营养不良症患儿左心室钆对比剂延迟强化序列高信号分布与心功能的相关性研究

Relationship between high signal distribution of left ventricular late gadolinium enhancement and cardiac function in children with Duchenne muscular dystrophy

目的:分析杜氏肌营养不良症(DMD)患儿左心室整体和局部钆对比剂延迟强化(LGE)序列高信号的分布,探讨其面积与心功能指标的相关性,为DMD患儿心脏损伤的早期识别与评估提供影像学依据。方法:病例对照研究。纳入深圳市儿童医院2022年1月至2023年1月诊断为DMD的男童(病例组46例)和经实验室及常规心血管磁共振(CMR)检查后排除心脏损伤可能且年龄、身高、体重与病例组匹配的男童(对照组23例),收集受试者临床、实验室、CMR电影及LGE序列资料,用t或U检验比较病例组和对照组的差异,计算患儿心肌纤维化指数,用Spearman相关系数分析其与心功能指标包括左心室射血分数(LVEF)、心肌肌钙蛋白I(cTnI)、氨基末端脑钠肽前体(NT-proBNP)和肌酸激酶同工酶(CK-MB)的关系。结果:所有受试者CMR检查均未发现心脏结构改变。对照组均未发现LGE序列高信号或左心功能不全,病例组患儿中28例(60.9%)出现LGE序列高信号,其中6例(13.0%)出现左心功能不全(LVEF<50%),其分布模式为基底段和中段的游离壁心外膜下心肌受累,最常受累的节段为基底段后壁(89.7%)、基底段侧壁(79.3%)、中段后壁(75.9%)。透壁性心肌受累组的LVEF低于非透壁性心肌受累组[53.1(47.7~58.1)%比59.0(58.0~62.9)%],差异有统计学意义(Z=-2.60,P=0.009)。患儿心肌纤维化指数与年龄、cTnI、NT-proBNP呈中度正相关(r=0.53、0.58、0.41,均P<0.05),与LVEF呈中度负相关(r=-0.51,P<0.05)。结论:DMD患儿左心室LGE高信号具有特定的分布模式,心肌纤维化的面积和透壁性受累的分布类型与心功能下降有关,LGE序列是识别及评估DMD患儿心脏受累的可靠工具。

Objective To analyze the distribution of global and regional late gadolinium enhancement(LGE)high signal of left ventricle in children with Duchenne muscular dystrophy(DMD)and explore the correlation between its area and cardiac function indexes,in order to provide imaging evidence for early identification and evaluation of cardiac injury in children with DMD.Methods A case-control study.From January 2022 to January 2023,46 boys(case group)were diagnosed with DMD in Shenzhen Children′s Hospital and while 23 boys(control group)were ruled out the possibility of heart injury by clinician after laboratory and routine cardiovascular magnetic resonance(CMR)examination and were matched the age,height and weight with the case group.The clinical,laboratory,CMR cine and LGE sequence data of the subjects were collected.The t or U test was used to compare the differences between the case group and the control group.The myocardial fibrosis index was calculated,and its relationships with cardiac function indexes such as left ventricular ejection fraction(LVEF),cardiac troponin I(cTnI),N-terminal pro-B-type natriuretic peptide(NT-proBNP)and creatine kinase MB(CK-MB)were analyzed using Spearman′s correlation coefficient.Results No cardiac structural changes were found in all subjects by CMR,and no high signal of LGE sequence or left ventricular dysfunction was found in boys in the control group.In the case group,LGE high signal was found in 28 cases(60.9%),among which 6 cases(13.0%)had left ventricular insufficiency(LVEF<50%).The distribution of LGE high signal was characterized by subepicardial involvement of the free wall of the basal and middle layer,and the most commonly involved segments were basal inferolateral(89.7%),basal anterolateral(79.3%),and mid inferolateral(75.9%).The LVEF in the transmural myocardial involvement group was lower than that in the non-transmural myocardial involvement group[53.1(47.7-58.1)%vs.59.0(58.0-62.9)%],and the difference was statistically significant(Z=-2.60,P=0.009).Myocardial fibrosis index was moderately positively correlated with age,cTnI and NT-proBNP(r=0.53,0.58 and 0.41,respectively,all P<0.05)while moderately negatively correlated with LVEF(r=-0.51,P<0.05).Conclusions There is a specific distribution pattern of left ventricular LGE high signal in children with DMD.The area of myocardial fibrosis and the distribution type of transmural involvement are related to the decline of cardiac function.LGE sequence is a reliable tool for identifying and evaluating cardiac injury in children with DMD.