Yang Chengzhi, Xu Haobo, Qiao Shubin, Jia Ruofei, Jin Zening, Yuan Jiansong
Department of Cardiology and Macrovascular Diseases, Beijing Tiantan Hospital, Capital Medical University, No. 119 South Fourth Ring West Road, Fengtai District, Beijing 100070, China.
Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China.
Diagnostics (Basel). 2022 Aug 22;12(8):2029. doi: 10.3390/diagnostics12082029.
Patients with obstructive hypertrophic cardiomyopathy (HOCM) have large papillary and trabecular muscles (PTMs), which are myocardial tissue. PTMs are usually excluded from the myocardium and included in the left ventricular (LV) cavity when determining LV mass (LVM) and volumes using cardiac magnetic resonance (CMR). This conventional method may result in large distortion of LVM and other indices. We investigated 74 patients with HOCM undergoing CMR imaging. LV short-axis cine images were obtained. LV contours were drawn using two different methods: (1) the conventional method, where PTMs were included in the LV cavity; and (2) the mask method, which includes the TPMs in the LV myocardium. The LV end-diastolic volume (LV-EDV), LV end-systolic volume (LV-ESV), LV ejection fraction (LVEF), and the LVM were then calculated. Fasting NT-proBNP and CK-MB levels were measured with ELISA. In patients with HOCM, mass of PTMs (MOPTM) was 47.9 ± 18.7 g, which represented 26.9% of total LVM. Inclusion of PTMs with the mask method resulted in significantly greater LVM and LVM index (both p < 0.0001) in comparison with those measured with the conventional method. In addition, the mask method produced a significant decrease in LV-EDV and LV-ESV. LVEF was significantly increased with the mask method (64.3 ± 7.9% vs. 77.2 ± 7.1%, p < 0.0001). MOPTM was positively correlated with BMI, septal wall thickness, LVM, LV-EDV, and LV-ESV. LVEF was inversely correlated with MOPTM. In addition, MOPTM correlated positively with NT-proBNP (r = 0.265, p = 0.039) and CK-MB (r = 0.356, p = 0.002). In conclusion, inclusion of PTMs in the myocardium has a substantial impact on quantification of the LVM, LV-EDV, LV-ESV, and LVEF in patients with HOCM. The effects of the PTMs in women was greater than that in men. Furthermore, the MOPTM was positively associated with NT-proBNP and CK-MB. The PTMs might be included in the myocardium when measuring the LV volumes and mass of patients with HOCM. At present, the clinical and prognostic meaning and relevance of the PTMs is not clear and should be further studied.
梗阻性肥厚型心肌病（HOCM）患者的乳头肌和小梁肌较大，属于心肌组织。在使用心脏磁共振成像（CMR）测定左心室（LV）质量（LVM）和容积时，乳头肌和小梁肌通常被排除在心肌之外并计入LV腔。这种传统方法可能导致LVM和其他指标的严重偏差。我们对74例接受CMR成像的HOCM患者进行了研究。获取了LV短轴电影图像。使用两种不同方法绘制LV轮廓：（1）传统方法，将乳头肌和小梁肌计入LV腔；（2）掩膜法，将乳头肌和小梁肌计入LV心肌。然后计算LV舒张末期容积（LV-EDV）、LV收缩末期容积（LV-ESV）、LV射血分数（LVEF）和LVM。用酶联免疫吸附测定法测量空腹NT-proBNP和CK-MB水平。在HOCM患者中，乳头肌和小梁肌质量（MOPTM）为47.9±18.7 g，占总LVM的26.9%。与传统方法相比，采用掩膜法计入乳头肌和小梁肌导致LVM和LVM指数显著更高（均p<0.0001）。此外，掩膜法使LV-EDV和LV-ESV显著降低。采用掩膜法时LVEF显著升高（64.3±7.9%对77.2±7.1%，p<0.0001）。MOPTM与体重指数、室间隔厚度、LVM、LV-EDV和LV-ESV呈正相关。LVEF与MOPTM呈负相关。此外，MOPTM与NT-proBNP呈正相关（r=0.265，p=0.039），与CK-MB呈正相关（r=0.356，p=0.002）。总之，将乳头肌和小梁肌计入心肌对HOCM患者的LVM、LV-EDV、LV-ESV和LVEF的量化有重大影响。乳头肌和小梁肌对女性的影响大于男性。此外，MOPTM与NT-proBNP和CK-MB呈正相关。在测量HOCM患者的LV容积和质量时，可能应将乳头肌和小梁肌计入心肌。目前，乳头肌和小梁肌的临床及预后意义和相关性尚不清楚，应进一步研究。
