A Clinical Study Of Surgical Treatment Of Obstructive Hypertrophic Cardiomyopathy

Background:The impact of septal myectomy on diastolic function in patients with obstructive hypertrophic cardiomyopathy is not well studied.There’s few research concerning diastolic function and pulmonary hypertension on patients with obstructive hypertrophic cardiomyopathy after septal myectomy surgery by use of cardiac catheterization.Methods:We performed transcatheter hemodynamic study on 12 patients with obstructive hypertrophic cardiomyopathy before and 3 to 6 months after septal myectomyResults:Postoperative hemodynamic studies were done 1 week before myectomy and 4.4±1.2 months after myectomy.The left ventricular outflow tract peak-to-peak gradient decreased from 83.2± 43.3 mmHg preoperatively to 11.6±4.3 mmHg after myectomy(P<0.00).The left ventricular diastolic time constant(Tau)was 64.2±26.1 ms before surgery and 42.2± 15.7 ms postoperatively(P=0.029).The average left atrial pressure(LAP)decreased from 20,2±7.0 mmHg to 12.1±4.5 mmHg after myectomy(P=0.008).Pulmonary artery hypertension was present in 6 patients preoperatively and remained in 2 patients after myectomy.Mean pulmonary artery pressure decreased from 29.3±16.2 mmHg to 20±6.7 mmHg posoper(P=0.05),and the systolic pulmonary artery pressure decreased from 46 ± 26.9 mmHg to 30.5±8.3 mmHg(P=0.048).Pulmonary vascular resistance decreased from 5.7±4.1 wood to 3.6±1.6 wood after surgery(P=0.032).Conclusions:Septal myectomy improved left ventricular diastolic function and subsequently relieved the right ventricular congestion in patients with obstructive HCM.Background:The factors influencing the development of pulmonary hypertension(PH)in patients with obstructive hypertrophic cardiomyopathy(OHCM)have not been fully elucidated,and the relationship between PH and the obstruction of the left ventricular outflow tract(LVOT)in patients with OHCM has not been reported.This study aimed to investigate the influencing factors of PH in patients with OHCM,and the relationship between pulmonary arterial pressure and LVOT gradient.Methods:Patients with OHCM were continuously enrolled from January to August 2021 to undergo right and left cardiac catheterization examination.The linear regression relationships between the mean pulmonary arterial pressure(MPAP)and left cardiac catheterization parameters were investigated.Results:Thirty-two patients underwent bilateral cardiac catheterization.14 patients(43.8%)were diagnosed with PH and assigned to the PH group,18(56.2%)were assigned to the non-PH group.The MPAP was significantly different between the PH and non-PH groups(35.4 ±14.5 mmHg vs.17.1 ± 4.4 mmHg,p<0.001).There was a significant difference in systolic pulmonary arterial pressure(SPAP)and diastolic pulmonary arterial pressure(DPAP)(p<0.001)between the two groups.Pulmonary vascular resistance(PVR)was 7.1±3.4 Woods and 3.5 ± 1.5 Woods in the PH and non-PH groups,respectively,with a significant difference(P=0.000)between the two groups.The mean left atrial pressure(MLAP)was 24.5 ± 7.8 mmHg and 15.9 ± 4.4 mmHg in the PH and non-PH groups,respectively,with a significant difference(P=0.000)between the two groups.Left ventricular end-diastolic pressure(LVEDP)was statistically different between the two groups(P=0.012).Univariate linear regression model demonstrated that LAD(P=0.012,R2=0.610),MLAP(P=0.000,R2=0.165),and LVOT gradient(P=0.00,R2=0.323)were linearly correlated with MPAP Multiple linear regression showed that LAD(P=0.006),MLAP(P=0.000),and LVOT gradient(P=0.001)jointly explained the 77.6%of the total variance of MPAP,fitting equation:PAP=0.63 ×LAD+0.310×LVOT gradient+0.259×MLAP-26.345(R=0.798,R2=0.776).)Conclusion:Pulmonary arterial hypertension in patients with OHCM is associated with increased left atrial pressure and enlarged left atrium,and the MPAP has a linear correlation with the LVOT gradient.Background:Although surgical treatment of residual obstruction after alcohol septal ablation is often challenging in patients with obstructive hypertrophic cardiomyopathy(OHCM),there are very few relevant clinical reports.Thus,outcomes of surgical septal myectomy in this subgroup of patients remain to be determined.Therefore,this study aimed to determine the surgical and follow-up outcomes in patients with OHCM exhibiting residual obstruction after alcohol septal ablation.Methods:We collected case data for 62 patients with OHCM and residual obstruction after alcohol septal ablation who underwent surgical septal myectomy at Fuwai Hospital between January 2002 and June 2019.Propensity score matching with patients having had a myectomy as the only invasive procedure-was conducted in a 1:2 ratio.Echocardiography parameters,surgery results,and follow-up outcomes were compared between the groups.Results:In the 62 cases of OHCM patients with previous ASA,male 44 cases and female 18 cases,mean aged 50.7±11.5 years old.In the 124 cases of OHCM patients with primary myectomy group,male 92 cases and female 32 cases,mean aged 50.2±11.1 years old.The prior alcohol septal ablation group had a higher incidence of right bundle branch block(RBBB)than the primary myectomy group preoperatively(38.7%vs 0)preoperatively(P<0.001).The prior alcohol septal ablation group had a higher incidence of complete atrioventricular block and subsequently postoperative permanent pacemaker implantation than the primary myectomy group(9.7%vs 1.6%,p=0.01).Two patients died within 30 days after surgery in the prior alcohol septal ablation group,and one patient died in the primary myectomy group,with an operative mortality rate of 3.2%and 0.8%,respectively(p=0.2).The 5-year event-free survival rate was 86.0%in the prior alcohol septal ablation group(median follow-up period:3.2 years;mean:3.9±2.6 years;maximum,10.6 years)and 88.5%in the primary myectomy group(median follow-up period:2.4 years;mean 2.8±1.7 years;maximum,9.1 years)(p=0.2).During follow-up,four of 62(6.5%)patients in the prior alcohol septal ablation group and one of 124(0.8%)patients in the primary myectomy group progressed to advanced heart failure(p=0.025).Conclusion:OHCM patients with previously alcohol septal alcohol ablation are at an increased risk of developing atrioventricular block after surgical septal myectomy.Their surgical outcomes,and long-term survival rate were satisfactory and,similar to those forpatients having had a myectomy as the only invasive procedure.In addition,they had an increased risk of advanced heart failure after surgical septal myectomy in the present study.