Search

Introduction:This study aims to analyze the clinical characteristics of patients with obstructive hypertrophic cardiomyopathy (OHCM) undergoing repeated septal reduction therapy (SRT), and preliminarily describe the genotype in the recruited patients.Methods:Patients with OHCM who received repeated SRT were recruited from 2014 to 2019 in Fuwai Hospital. Patients were divided into septal myectomy (SM) group or alcohol septal ablation (ASA) group according to the primary procedure of SRT. Sixteen of these patients underwent genetic testing. Pathogenic mutations were those mutations identified as pathogenic, likely pathogenic, or variants of uncertain significance according to the ACMG criteria.Results:A total of 31 patients (21 males) was included. The average age was 48.7±12.2 years. There were 7 patients in the SM group and 24 patients in the ASA group. Preoperative electrocardiogram showed that 7 patients in the ASA group presented with complete right bundle branch block (CRBBB). After the operation, 4 patients were implanted with permanent pacemakers due to complete atrioventricular block, of which 3 patients were in the ASA group with CRBBB. Pathogenic mutations were identified in 50.0% (8/16) of the study patients. Pathogenic mutations were mostly located in the MYH7 gene (5/9,55.6%), MYBPC3 gene (3/9,33.3%), and TNNT2 gene (1/9,11.1%). There was no difference between patients carrying pathogenic mutations or not, in terms of interventricular septal thickness and left ventricular outflow tract gradient. During the perioperative period, except for one death caused by electrical storm, the remaining patients had no serious complications. The results of follow-up echocardiography showed that except for 2 patients who had left ventricular outflow tract obstruction again, the thickness of interventricular septum and left ventricular outflow tract gradient was significantly lower compared with preoperative echocardiography.Conclusions:In conclusion, the surgery of SM is an effective treatment in OHCM patients with a history of previous SRT procedures. Patients with the first procedure of ASA are at high risk of developing atrioventricular block after a repeated SM.

Introduction:Hypertrophic cardiomyopathy (HCM) is the most prevalent inherited heart disease. The presence of a sarcomere mutation is a powerful predictor of adverse outcomes. Two-thirds of the patients are obstructive HCM (OHCM). Atrial fibrillation (AF), a common complication, is associated with poor long-term prognosis in OHCM patients. However, the effect of sarcomere mutation on the clinical phenotype or prognosis in OHCM patients with AF is unknown.Methods and Results:We retrospectively collected 41 OHCM patients with AF who underwent septal myectomy in Fuwai hospital which were separated into 2 groups, sarcomere mutation (+) group and sarcomere mutation (-) group (n=25 and 16). Statistical analysis was performed by Mann-Whitney Utest, Chi-square test, Kaplan-Meier survival analysis, and log-rank test with SPSS 23.0 and GraphPad 8.0. Patients in sarcomere mutation (+) group were younger (42.0±14.5 vs. 57.6±11.7 years, p=0.001). There was no significant difference between sarcomere mutation (+) and sarcomere mutation (-) group on other baseline variables and prognosis (log-rank p=0.077).Conclusions:In conclusion, we did not find that the presence of a sarcomere mutation worsen the prognosis in OHCM patients with AF. Multi-center prospective studies with large samples are needed to further confirm our results.