Hu Li-Wei, Liu Xin-Rong, Wang Qian, Barton Gregory P, Ouyang Rong-Zhen, Sun Ai-Min, Guo Chen, Han Tong-Tong, Yao Xiao-Fen, François Christopher J, Zhong Yu-Min
Diagnostic Imaging Center, Shanghai Children's Medical Center Affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China.
Department of Cardiothoracic Surgery, Shanghai Children's Medical Center Affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China.
Quant Imaging Med Surg. 2020 Feb;10(2):485-495. doi: 10.21037/qims.2020.01.07.
This study aimed to investigate the associations between cardiac strain, cardiac torsion, ventricular volumes, and ventricular ejection fraction, with N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in Fontan patients who were age- and gender-matched with healthy control subjects.
Cardiovascular magnetic resonance (CMR) studies performed in 22 (15 male, 7 female) patients with single-ventricle physiology (all morphological left ventricles) palliated with Fontan and 17 (10 male, 7 female) age- and gender-matched healthy children volunteers were retrospectively analyzed. Serum NT-proBNP levels were obtained in Fontan subjects. Standard post-processing of CMR images included systemic ventricular end-diastolic and end-systolic volumes, stroke volume, cardiac mass, atrioventricular regurgitation, and ejection fraction. CMR tissue tracking (TT) software was used to quantify global longitudinal strain (GLS), global radial strain (GRS), and global circumferential strain (GCS) and torsion of the systemic ventricle. Pearson and Spearman correlation coefficients were used in comparisons of correlations between NT-proBNP and functional parameters in repair Fontan patients. Intra-observer and inter-observer variability of CMR strain and torsion values were determined from 10 randomly selected Fontan subjects and 10 randomly selected control subjects.
GLS was significantly lower in Fontan patients than in control subjects (-15.19±2.94 -19.97±1.70; P<0.001). GLS was not significantly different between normal NT-proBNP levels and high NT-proBNP levels in Fontan patients (-15.59±2.72 -14.62±3.32; P=0.462). The GCS of repair Fontan patients was not significantly lower than that of the control group (-16.76±3.27 -17.88±2.26; P=0.235). GCS was significantly different between normal and high NT-proBNP levels group in Fontan patients (-17.95±2.43 -15.04±3.67; P=0.036). The peak systolic torsion and peak systolic torsion rates were significantly lower in Fontan patients than in control subjects (0.81±0.41 1.07±0.36, P=0.044; 7.36±3.41 9.85±2.61, P=0.017). Peak systolic torsion was significantly lower in Fontan patients with normal NT-proBNP levels than in high NT-proBNP subjects (0.67±0.43 1.01±0.29; P=0.036). GCS and torsion were more strongly correlated with NT-proBNP in the patient group (r=0.541 for GCS; r=0.588 for torsion, P<0.01). The parameters of strain and torsion could be reproduced with sufficient accuracy by intra-observer agreement(biases =0.04 for GLS; biases =0.66 for GCS; biases =1.03 for GRS; biases =0.04 for torsion) and inter-observer agreement (biases =0.32 for GLS; biases =0.85 for GCS; biases =1.52 for GRS; biases =0.18 for torsion).
GLS is an earlier marker of contractile dysfunction in repair Fontan patients. Peak systolic torsion may be a biomarker for determining subclinical dysfunction, as it is more strongly correlated with serum biomarkers of ventricular function than ventricular size or ejection fraction.
本研究旨在调查与健康对照受试者年龄和性别匹配的Fontan患者中心肌应变、心脏扭转、心室容积和心室射血分数与N末端B型利钠肽原（NT-proBNP）水平之间的关联。
回顾性分析了22例（15例男性，7例女性）接受Fontan姑息治疗的单心室生理（均为形态学左心室）患者和17例（10例男性，7例女性）年龄和性别匹配的健康儿童志愿者的心血管磁共振（CMR）研究。获取了Fontan受试者的血清NT-proBNP水平。CMR图像的标准后处理包括体循环心室舒张末期和收缩末期容积、每搏输出量、心脏质量、房室反流和射血分数。使用CMR组织追踪（TT）软件量化体循环心室的整体纵向应变（GLS）、整体径向应变（GRS）、整体圆周应变（GCS）和扭转。Pearson和Spearman相关系数用于比较修复Fontan患者中NT-proBNP与功能参数之间的相关性。通过从10例随机选择的Fontan受试者和10例随机选择的对照受试者中确定CMR应变和扭转值的观察者内和观察者间变异性。
Fontan患者的GLS显著低于对照组（-15.19±2.94对-19.97±1.70；P<0.001）。Fontan患者中正常NT-proBNP水平和高NT-proBNP水平之间的GLS无显著差异（-15.59±2.72对-14.62±3.32；P=0.462）。修复Fontan患者的GCS不显著低于对照组（-16.76±3.27对-17.88±2.26；P=0.235）。Fontan患者中正常和高NT-proBNP水平组之间的GCS有显著差异（-17.95±2.43对-15.04±3.67；P=0.036）。Fontan患者的收缩期峰值扭转和收缩期峰值扭转率显著低于对照组（0.81±0.41对1.07±0.36，P=0.044；7.36±3.41对9.85±2.61，P=0.017）。NT-proBNP水平正常的Fontan患者的收缩期峰值扭转显著低于高NT-proBNP受试者（0.67±0.43对1.01±0.29；P=0.036）。患者组中GCS和扭转与NT-proBNP的相关性更强（GCS的r=0.541；扭转的r=0.588，P<0.01）。应变和扭转参数可以通过观察者内一致性（GLS的偏差=0.04；GCS的偏差=0.66；GRS的偏差=1.03；扭转的偏差=0.04）和观察者间一致性（GLS的偏差=0.32；GCS的偏差=0.85；GRS的偏差=1.52；扭转的偏差=0.18）以足够的准确性再现。
GLS是修复Fontan患者收缩功能障碍的早期标志物。收缩期峰值扭转可能是确定亚临床功能障碍的生物标志物，因为它与心室功能的血清生物标志物的相关性比心室大小或射血分数更强。
