[The role of three-dimensional speckle tracking imaging derived parameters on predicting outcome of hypertrophic cardiomyopathy patients with MYH7 mutations].

Objective: To evaluate the cardiac functional changes in hypertrophic cardiomyopathy(HCM) patients with β-myosin heavy chain gene (MYH7) mutations by three-dimensional (3D) speckle tracking imaging(3D-STI) and conventional echocardiography modalities, and then to explore the potential predictors of adverse cardiovascular events in these patients. Methods: A consecutive series of 192 HCM patients admitted in our center from October 2014 to October 2016 were genetically screened to identify MYH7 mutations in this retrospective study. A total of 43 HCM patients with MYH7 mutations were enrolled. The patients were divided into events group(n=13) and no event group(n=30) according to the presence or absence of adverse cardiovascular events(primary and secondary endpoints). All patients were followed up to January 2019 after comprehensive evaluation of 3D-STI, two-dimensional and Doppler echocardiography. The adverse cardiovascular events were recorded. Results: The median follow up time was 1 012 (812, 1 330) days. During follow-up, 13 patients (30.2%) reached endpoints: 6 cases of the primary endpoints(2 cases of sudden cardiac death(SCD), 3 cases of survival after defibrillation, and 1 case of appropriate implantable cardioverter-defibrillator(ICD) discharge); 7 cases of the second endpoints(5 cases of heart failure hospitalization, 1 case of syncope and cardioversion due to supraventricular tachycardia, and 1 case of end-stage HCM). Patients with adverse cardiovascular events had higher prevalence of syncope and risk of SCD, enlarged left atrial volume index(LAVI) and reduced 3D left ventricular global longitudinal train (3D-GLS), as compared to those without adverse events(all P<0.05). The multivariate Cox regression analysis showed that reduced 3D-GLS(HR=0.814, 95%CI 0.663-0.999, P=0.049) was an independent predictor for adverse cardiovascular events. The cutoff value of 3D-GLS≤13.67% was linked with significantly increased risk of adverse cardiovascular events in this patient cohort(AUC=0.753, 95%CI 0.558-0.948, sensitivity 86%, specificity 69%, P<0.05). The Kaplan-Meier analysis indicated that the patients with the 3D-GLS≤ 13.67% faced higher risk of death than those with 3D-GLS>13.67%. Conclusion: 3D-GLS is useful on predicting adverse cardiovascular events in HCM patients with MYH7 mutations.