A Clinical Study Of Hypertrophic Obstructive Cardiomyopathy

Background and aim:Recently alcohol septal ablation(ASA)has emerged as an alternative treatment for drug-refractory hypertrophic obstructive cardiomyopathy(HOCM)and a subgroup of HOCM patients with previous ASA may need myectomy.However,subsequent outcome and mechanism of residual obstruction has not been determined.This study aims to determine outcome after myectomy and mechanism of residual obstruction in HOCM patients with previous ASA.Methods:From February 2009 to June 2017,thirty-eight HOCM patients with previous ASA underwent surgical septal myectomy at our institution.Seventy-six patients who underwent surgical septal myectomy initially were included as the comparison group through one-to-two propensity score matching method.Results:Fourteen available cardiac magnetic resonance images revealed inferior location and small area of infarcted myocardium induced by ASA in 12 patients and outside targeted location in 2 patients.During follow-up(median 2.4;maximum 7.8 years),event-free survival at 7 years was 83.2%in the previous ASA group and 94.6%in the comparison group,respectively(P=0.0378).Multivariable Cox proportional hazards regression analysis indicated previous ASA(hazard ratio 4.28,95%CI 1.20-15.26;p=0.025)and postoperative left ventricular end-diastolic diameter(hazard ratio 1.14,95%CI 1.05-1.23;p=0.002)were independent predictors of adverse events.Conclusions:This study demonstrated that uncontrollable extent and location of infarcted myocardium induced by ASA may attribute to residual obstruction after previous ASA,and the long-term event-free survival after myectomy was inferior.It may provide special precaution to patient selection and the rapidly increased number of ASA practiced worldwide.Background.Contemporary experiences regarding childhood hypertrophic obstructive cardiomyopathy are limited.This study aimed to describe the clinical presentation of childhood hypertrophic obstructive cardiomyopathy and its relevant surgical outcome.Methods.A total of 117 consecutive children with hypertrophic obstructive cardiomyopathy aged 0.6-17.5 years who underwent septal myectomy at our institution between February 2009 and December 2018 were included.Medical records and other patient-related data were reviewed.Results.In the present study,the anatomical and physiological characteristics of childhood hypertrophic obstructive cardiomyopathy were highly heterogeneous,with simultaneous right ventricular outflow tract obstruction in 22 patients(18.8%),coronary myocardial bridging in 25 patients(21.4%),and intraventricular anatomical abnormalities in 61 patients(52.1%).The mean peak left or right ventricular outflow tract gradient,interventricular septal thickness,and degree of mitral regurgitation significantly decreased after surgery.One early death was noted in the study.During follow-up,3 sudden cardiac deaths were noted.The overall survival rates at follow-up were 100%at 1 year and 96.5%at 3 years.The overall survival rates free from reoperation were 99.1%at 1 year and 98.0%at 3 years.Conclusions.In our cohort of children with hypertrophic obstructive cardiomyopathy undergoing septal myectomy,biventricular obstruction,myocardial bridging,and intraventricular anatomical abnormalities are frequent phenotypic components.Despite the complexity of childhood hypertrophic obstructive cardiomyopathy,surgical treatment results in a favorable outcome in carefully selected patients.OBJECTIVES The present study aims to investigate the prevalence and morphologic characteristics of intramural coronary artery(ICA)in patients with hypertrophic obstructive cardiomyopathy(HOCM)on coronary computed tomographic(CT)angiography and invasive coronary angiography.BACKGROUND The prevalence and morphologic characteristics of ICA in patients with HOCM are not fully known.METHODS Patients with a diagnosis of HOCM referred to hospital for selective myectomy surgery were prospectively included into the present study between September 2015 and June 2019 at Fuwai Hospital.Both preoperative coronary CT and invasive angiography were scheduled.RESULTS ICA was observed in 106(23.3%)out of 455 patients on coronary CT angiography and dynamic compression of coronary artery was present in 87 patients(19.1%)on invasive coronary angiography.ICA covered with complete myocardial encasement was found in 98 patients(92.5%)with deep myocardial bridging(MB)most frequently observed(p=0.005).All patients with dynamic compression of coronary artery had ICA.Seventy-seven patients(16.9%)had dynamic luminal reduction≥ 50%in the entire study population.Pearson linear correlation analysis revealed that the length and degree of dynamic compression was significantly related with MB depth and length(Pearson correlation r=0.241,0.581,0.316,and 0.209;P=0.014,<0.001,0.002 and 0.032,respectively).CONCLUSIONS ICA is common in patients with HOCM and can be visualized well by coronary CT.Deep or extensive MB is more likely produce coronary dynamic compression.Preoperative identification of this congenital coronary artery variant may be helpful to surgical planning.