Evaluation of myocardial microcirculation perfusion in patients with hypertrophic obstructive cardiomyopathy after Liwen procedure by myocardial contrast echocardiography / 中华超声影像学杂志

ABSTRACT

Objective:To quantitatively evaluate myocardial microcirculation perfusion changes after percutaneous intracardiac septal radiofrequency ablation (PIMSRA, Liwen procedure) in patients with obstructive hypertrophic cardiomyopathy (HOCM) using myocardial contrast echocardiography (MCE) and to further establish the effect of the procedure and predict the long-term prognosis of patients.Methods:A total of 45 patients with HOCM treated by the Liwen procedure in the First Affiliated Hospital of Air Force Medical University (Xijing Hospital) from July 2019 to June 2020 were included. MCE was performed before and 6 months after surgery, respectively. Time-intensity perfusion curve analysis was performed using QLab 10.8 offline software to obtain quantitative parameters of myocardial microcirculation perfusion including myocardial blood volume (A value), myocardial blood flow velocity (β value), and myocardial blood flow (A×β value), then the changes in parameters before and after the procedure were compared.Results:After the Liwen procedure, the mean septal thickness and mean left ventricular free wall thickness were significantly reduced, accompanied by a significant reduction in the left ventricular outflow tract pressure gradient (LVOT-PG) and mitral regurgitation length, and a significant improvement in mitral systolic antegrade motion (SAM) (all P<0.001). In addition, the left ventricular ejection fraction (LVEF) did not deteriorate significantly ( P=0.560) and the E/e′ ratio decreased after the procedure ( P=0.015). Besides, the A values of both the ventricular septum and the left ventricular free wall were not significantly changed compared to those before procedure ( P>0.05), whereas the β values and A×β values were obviously increased ( P<0.05). Conclusions:Myocardial blood velocity and myocardial blood flow in the septum and left ventricular free wall were significantly increased in patients with HOCM after the Liwen procedure, suggesting a significant improvement in myocardial microcirculation perfusion. MCE provides a non-invasive quantitative evaluation parameters of myocardial microcirculation perfusion for the Liwen procedure for the treatment of HOCM.