A follow-up study of percutaneous intramyocardial septal radiofrequency ablation in the treatment of obstructive hypertrophic cardiomyopathy with mild septal hypertrophy / 中华超声影像学杂志

ABSTRACT

Objective:To evaluate the clinical efficacy of percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) in the treatment of obstructive hypertrophic cardiomyopathy (HOCM) with mild septal hypertrophy.Methods:Forty-five HOCM patients with mild septal hypertrophy (the maximal left ventricular wall thickness is 15-19 mm) who were treated with PIMSRA between November 2016 to February 2021 in the Hypertrophic Cardiomyopathy Center of Xijing Hospital of Air Force Military Medical University were enrolled, and their clinical datas were collected and analyzed. The clinical symptoms and NYHA functional class before operation, 6 months and 1 year after operation were collected. Interventricular septum thickness, left ventricular outflow tract pressure gradient, left ventricular outflow tract diameter, mitral regurgitation, left ventricular systolic and diastolic function were evaluated by transthoracic echocardiography before operation, 6 months and 1 year after operation, intraoperative complications were monitored and recorded. Postoperative arrhythmias were monitored by routine 12 lead ECG and 24-hour ambulatory ECG.Results:All patients successfully completed PIMSRA procedure.No clinical adverse events such as death, bleeding and stroke occurred during and around the operation.No left bundle branch block, complete atrioventricular block and malignant arrhythmia occurred after the operation. All patients did not need permanent pacemaker implantation.NYHA functional class and clinical symptoms of patients were significantly improved after 6 months compared with values before operation (all P<0.001, respectively), it remained stable for 1 year after operation; Anterior interventricular septum, posterior interventricular septum, maximal left ventricular wall thickness all significantly decreased (all P<0.001, respectively), left ventricular outflow tract diameter widened ( P<0.001), continuous improvement 1 year after operation; left ventricular outflow tract gradient and provoked left ventricular outflow tract gradient all significantly decreased, mitral regurgitation decreased and SAM classification reduced after 6 months compared with values before operation (all P<0.001, respectively); left ventricular end-diastolic diameter widened and left atrial diameter decreased (all P<0.001, respectively), it remained stable for 1 year after operation. Left atrial volume index decreased ( P<0.001), with continuous improvement 1 year after operation; The ratio of early diastolic mitral valve velocity to early diastolic mitral annulus velocity (E/e′) decreased ( P=0.001), it remained stable for 1 year after operation. There were no significant differences in left ventricular end diastolic volume, left ventricular end systolic volume and left ventricular ejection fraction among the three groups (all P>0.05). Conclusions:PIMSRA is effective in the treatment of obstructive hypertrophic cardiomyopathy with mild ventricular septal hypertrophy.