Study of left ventricular myocardial mechanics in patients with different risk stratifications of hypertrophic cardiomyopathy by four-dimensional automatic left ventricular quantitation technology / 中华超声影像学杂志

ABSTRACT

Objective:To explore the application value of four-dimensional automatic left ventricular quantitation(4D Auto LVQ) technology, in evaluating the myocardial mechanics in patients with different risk stratifications of hypertrophic cardiomyopathy(HCM).Methods:A total of 88 HCM patients and 20 healthy volunteers were selected from February 2020 to February 2022 in the First Affiliated Hospital of Zhengzhou University. According to the HCM Risk-SCD score, HCM patients were divided into 3 groups low-risk group( n=49), intermediate-risk group( n=21), and high-risk group( n=18). Conventional ultrasound parameters were collected, and 4D Auto LVQ technology was used to obtain the mechanical parameters of left ventricular myocardium, including global longitudinal strain(GLS) , global circumferential strain(GCS), global area strain(GAS), global radial strain(GRS), twist and torsion. The differences in these parameters among the four groups were compared. The predictive values of conventional ultrasound parameters and myocardial mechanical parameters in patients with intermediate- and high-risk HCM patients were analyzed by ROC curve. Results:①Left ventricular end-diastolic diameter, left ventricular end-diastolic volume, left ventricular end-systolic volume, and peak systolic velocity of mitral annulus in the low-, intermediate-, and high-risk groups were lower than those in the control group while left ventricular maximal wall thickness(LVMWT) and early diastolic peak velocity of mitral value orifice/early diastolic peak velocity of mitral annulus(E/e′) were higher, left atrial diameter(LAD) and left ventricular outflow tract gradients(LVOTG) in the intermediate- and high-risk groups were higher than the low-risk group(all P<0.05). ②Compared with the control group, the GLS of HCM patients was lower, and the GLS of the intermediate- and high-risk groups was lower than the low-risk group. GCS and GRS in the intermediate- and high-risk groups were lower than those in the low-risk group. GAS in the high-risk group was lower than the low-risk and the control group, but higher than the intermediate-risk group(all P<0.05). Compared with the control group, the twist and torsion in the intermediate- and high-risk groups were higher, but lower than the low-risk group, and the differences were statistically significant(all P<0.05). ③The ROC results showed that the area under the curve(AUC) of the model containing conventional ultrasound parameters(LVWMT, LAD, and LVOTG) for predicting intermediate- and high-risk HCM patients was 0.811, with a sensitivity of 0.769 and a specificity of 0.755. The AUC of the conventional ultrasound parameters combined with myocardial mechanical parameters was 0.904, as the sensitivity was 0.667 and the specificity was 0.980. Conclusions:4D Auto LVQ can evaluate the mechanical characteristics of LV myocardium in HCM patients with different risk stratifications. Myocardial mechanical parameters combined with conventional ultrasound parameters can improve the diagnostic performance of patients with intermediate- and high-risk HCM.