Residual Left Ventricular Outflow Tract Research Articles

Microcatheter-Facilitated Alcohol Septal Ablation For Residual Left Ventricular Outflow Tract Obstruction

Microcatheter-Facilitated Alcohol Septal Ablation For Residual Left Ventricular Outflow Tract Obstruction

Outcomes of surgical septal myectomy for obstructive hypertrophic cardiomyopathy after previous septal reduction therapy

ObjectiveTo compare early and late outcomes of septal myectomy in patients with obstructive hypertrophic cardiomyopathy who presented with residual or recurrent left ventricular outflow tract (LVOT) obstruction after previous septal-reduction therapy (SRT). MethodsFrom January 1989 to March 2022, 145 patients underwent reintervention by septal myectomy for residual LVOT obstruction after previous SRT; 72 patients had previous alcohol septal ablation (ASA) and 73 had previous surgical septal myectomy. Baseline patient characteristics, echocardiographic parameters, and surgical outcomes were compared between these 2 groups. ResultsPatients who had previous ASA were more likely to be male (50.0% vs 30.1%; P = .015), be older (median age 57.5 years vs 48.3 years; P < .001), and have a greater body mass index (32.7 kg/m2 vs 30.0 kg/m2; P = .011). After repeat SRT by septal myectomy, there was no significant difference in the incidence of postoperative complete heart block, necessitating permanent pacemaker, between the 2 groups (8.3% vs 2.7%; P = .151). One (0.7%) patient died within 30 days of surgery. Over a median follow-up of 7.5 years (interquartile range, 3.0-13.8), there were 20 deaths. Kaplan-Meier 5-, 10-, and 15-year survival rates were 100%, 91%, and 76% for the previous septal myectomy group, and 93%, 81%, and 64% for the previous ASA group (P = .207). ConclusionsSeptal myectomy for residual or recurrent LVOT obstruction in patients who had previous ASA is safe, with an acceptably low rate of postoperative complete heart block. Surgical outcomes and late survival rates in patients with complete heart block ASA were satisfactory and comparable with patients who underwent repeat myectomy.

Mitral regurgitation mechanisms related to systolic anterior motion in hypertrophic cardiomyopathy.

Systolic anterior motion (SAM) of the mitral valve can result in mitral regurgitation (MR) and adverse outcomes in patients with obstructive hypertrophic cardiomyopathy (HCM). However, the mechanism and characteristics of MR severity mediated by SAM are unresolved. This study aimed to elucidate the anatomic and hemodynamic associations of MR and the impact of septal myectomy on changes in MR severity in patients with HCM. We retrospectively reviewed patients who underwent septal myectomy with SAM and interpretable imaging between 2017-2022. Significant MR was defined as moderate or more MR. The mitral valve, papillary muscle, and left ventricular geometry were quantitatively evaluated via echocardiography and cardiac computed tomography. Out of 34 patients, two groups were identified: those with preoperative significant MR (n=16) and those without significant MR (n=18). Patients with significant preoperative MR exhibited worse heart failure symptoms at baseline than those without. Following myectomy, these patients showed higher residual left ventricular outflow tract (LVOT) gradients at rest and with provocative measures than those without preoperative MR. Multivariate regression analysis revealed a significant association between the tenting area and MR severity. Additionally, the chordal cutting procedure alleviated the tenting area [2.1 (1.8-2.6) vs. 1.4 (1.2-1.6) cm2] compared to those without it. Our preliminary data suggested that chordal cutting with septal myectomy was associated with an improvement in the tenting area, contributing to MR severity. This procedure may serve as an effective therapy for patients with SAM and significant MR.

Management of the mitral valve in thoracoscopic trans-mitral myectomy for hypertrophic obstructive cardiomyopathy

ObjectiveThis study aimed to compare clinical outcomes of different mitral valve (MV) management methods in thoracoscopic transmitral myectomy (TTM) and guide surgeons' decision making for hypertrophic obstructive cardiomyopathy (HOCM). MethodsSeventy-three consecutive patients (41 females; mean age, 53.7 ± 13.6 years) with HOCM who underwent TTM between January 2019 and October 2022 were enrolled and divided into 3 groups according to MV surgical strategy. Clinical outcomes were analyzed and compared among the groups. ResultsNone of the patients experienced postoperative residual left ventricular outflow tract obstruction. Percentages of patients with mitral regurgitation (MR) grade ≥3+ (57.5% vs 1.4%) and systolic anterior motion (95.9% vs 2.7%) were significantly decreased postoperatively (P < .001 for both). The preoperative anterior mitral leaflet length was longer in patients in the anterior mitral leaflet direct reattachment group (median, 2.9 cm [interquartile range (IQR), 2.7-3.3 cm] vs 2.7 [IQR, 2.4-2.9 cm]; P = .018), but the postoperative coaptation length was shorter (mean, 8.3 ± 2.1 mm vs 11.1 ± 3.8 mm; P = .038). After a median echocardiography follow-up of 11.8 months, the left ventricular outflow tract gradient (LVOTG) and mitral regurgitation grades remained significantly improved in all 3 groups (P < .05 for all). ConclusionsTotal TTM in selected patients is safe and effective, and all 3 MV management strategies can significantly reduce the LVOTG while improving MR. Mitral valvuloplasty is the preferred initial management strategy over valve replacement except in the scenario of irreparable intrinsic MV disease and valvuloplasty failure.

Hemodynamic Predictors of Outcome Following Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy.

Alcohol septal ablation (ASA) is a minimally invasive treatment for drug-refractory obstructive hypertrophic cardiomyopathy. Detailed assessment of pressure changes and predictors of mortality and procedure success are not well defined. This is a single-center study evaluating pressure changes and predictors of mortality and procedure success in transseptal ASA. Survival analysis and predictors of mortality were assessed using the Kaplan-Meier analysis and Cox regression, respectively. A total of 156 patients were included (mean age, 67.3 years; 46.8% women). Left atrial (LA) pressure and left ventricular outflow tract (LVOT) gradient decreased, whereas aortic pulse pressure (PP) increased post-ASA. Patients with lower baseline mean LA pressure (<median, 19 mm Hg), LVOT gradient reduction >82% (gradient change median), and PP increase >19% (PP change median) had superior survival. On Cox univariable regression, baseline mean LA pressure >median (19 mm Hg; hazard ratio [HR], 2.09 [95% CI, 1.05-4.18]; P=0.036), residual LVOT gradient (HR, 1.02 [95% CI, 1.01-1.03]; P=0.003), and LVOT gradient percent reduction <median (82%; HR, 2.92 [95% CI, 1.46-5.83]; P=0.002) were predictors of mortality. When adjusting for age and sex, baseline LA v wave >median (28 mm Hg; HR, 2.36 [95% CI, 1.17-4.76]; P=0.016), baseline mean LA pressure >median (19 mm Hg; HR, 2.70 [95% CI, 1.33-5.50]; P=0.006), percentage reduction in gradient <median (82%; HR, 2.74 [CI, 1.37-5.50]; P=0.005), and percentage increase in PP <median (19.3%; HR, 2.09 [CI, 1.05-4.16]; P=0.035) predicted survival free of all-cause mortality. ASA is associated with an acute decrease in the LVOT gradient and LA pressures and increase in aortic PP. Mean LA pressure, percentage decrease in LVOT gradient, and increase in PP are strong predictors of survival free of all-cause mortality following ASA and are important variables for procedural guidance.

Feasibility and safety of transseptal transcatheter mitral valve replacement for severe mitral regurgitation

A prospective, single-center, single-arm, and open-design study was performed to evaluate the feasibility and safety of transseptal transcatheter mitral valve replacement in the treatment of severe mitral regurgitation. Patients with symptomatic moderate-severe or severe mitral regurgitation at high-surgical risk and anatomically appropriate for the HighLife transseptal mitral valve replacement (TSMVR) system in West China Hospital, Sichuan University from December 2021 to August 2022 were enrolled. Four patients (1 male and 3 females) with severe mitral regurgitation were included, with a median age of 68.5 (64.0-77.0) years and a median Society of Thoracic Surgeons (STS) score of 8.1% (6.4%-8.9%). Technical success was achieved in all the patients. There was no residual mitral regurgitation, paravalvular leakage, or left ventricular outflow tract obstruction. Three major cardiovascular and cerebrovascular adverse events occurred within 30 days after the procedure, including ventricular tachycardia, iatrogenic atrial septal defect closure, and heart failure readmission. The current study preliminarily demonstrates that transcatheter mitral valve replacement using the HighLife system via the transseptal approach for severe mitral regurgitation is feasible and relatively safe.

Minimally invasive cardiac surgery for complex procedures: extensive septal myectomy and double valve replacement

In this video tutorial, we demonstrate that minimally invasive cardiac surgery and all its benefits can be applied even to complex, multiple cardiac procedures. We present a 71-year-old patient with severely obstructive hypertrophic cardiomyopathy, moderate mitral regurgitation for systolic anterior motion of the mitral valve, moderate aortic stenosis and regurgitation and atrial fibrillation. We performed a mitroaortic valve replacement, transmitral and transaortic septal myectomy and left atrial appendage closure through a minimally invasive approach (right anterolateral minithoracotomy). After establishing peripheric cardiopulmonary bypass, aortic cross-clamping and a left atrium opening, the anterior mitral leaflet was incised circumferentially at its insertion on the annulus to allow an optimal transmitral myectomy. Subsequently, mitral valve removal was completed, and a bioprosthesis was implanted. After closure of the left atrium, the left atrial appendage was closed using a 40-mm device (Atriclip). The aorta was then opened, the aortic valve was excised and a transaortic septal myectomy was completed. Finally, a sutureless aortic bioprosthesis was implanted. Postoperative transoesophageal and transthoracic surgery demonstrated a residual left ventricular outflow tract gradient of 14 mmHg and the correct performance of both biological prostheses. Minimally invasive heart surgery can be offered even to patients requiring complex and multiple procedures, including septal myectomy. Combining the benefits of the operation with those of a minimally invasive approach may optimize postoperative and long-term surgical outcomes.

Long-term outcomes of primary aortic valve repair for isolated congenital aortic stenosis in children

ObjectiveWe aimed to assess the long-term outcomes of children with isolated congenital aortic stenosis who underwent primary aortic valve repair. MethodsRecords of all children (n = 111) with isolated congenital aortic stenosis who underwent primary aortic valve repair between 1980 and 2016 were reviewed. An optimal operative outcome consisted of a residual left ventricular outflow tract peak systolic gradient <35 mm Hg and trivial or less aortic insufficiency. ResultsMedian age at surgery was 0.4 years (interquartile range, 1 month-7.9 years) and median weight at surgery was 7.0 kg (interquartile range, 3.7-25.0 kg). Fifty-two patients (46.8%; 52/111) underwent aortic valve repair with the use of patch material. Early mortality was 0.9% (1/111). Late mortality was 0.9% (1/110). Freedom from aortic valve reoperation was 52.1% (95% CI, 38.7-63.8) at 10 years. Freedom from aortic valve replacement was 67.9% (95% CI, 55.4-77.5) at 10 years. An optimal outcome was achieved in 48 patients (43.2%; 48/111). At 10 years, freedom from aortic valve reoperation was 78.2% (95% CI, 63.1-87.8) in patients with an optimal outcome, compared with 39.4% (95% CI, 22.8-55.6) in those with a suboptimal outcome (P = .03). Tricuspid aortic valve was associated with a suboptimal outcome (P = .01). ConclusionsAortic valve repair achieves relief of congenital aortic stenosis with very low early mortality and excellent long-term survival, even in neonates. Although nearly half of the patients required aortic valve reoperation by 10 years, two-thirds of the patients remain free from aortic valve replacement. An optimal outcome was more commonly achieved with bicuspid aortic valves compared with tricuspid aortic valves.

Surgical Septal Myectomy for the Treatment of Residual Left Ventricular Outflow Tract Obstruction Following Failed Alcohol Septal Ablation.

The reasons of residual left ventricular outflow tract (LVOT) obstruction following alcohol septal ablation (ASA) remain unclear, and outcomes of myectomy following failed ASA remain underreported.Thirteen symptomatic patients (10 women, a median age of 60.0 years) who underwent septal myectomy following failed ASA were reviewed. The patients were followed up for a median of 6 months. The clinical characteristics and outcomes of these patients were analyzed and were compared with those of 178 patients who underwent isolated myectomy without previous ASA at our institution during the same period.In the first ASA procedure, the median number of septal perforator arteries injected was 1.0 with the median value of peak creatine kinase following ablation of 978.5 U/L.Uncontrollable extent and location of infarcted myocardium caused by ablation and mitral subvalvular anomalies were found in four (30.8%) and seven (53.8%) patients, respectively. No operative or follow-up deaths occurred. The median maximum LVOT gradients fell from preoperative 112.0 to 8.5 mmHg at follow-up (P < 0.001). Compared with controls, patients with failed ASA had a higher proportion of mitral subvalvular anomalies (53.8% versus 13.5%, P = 0.001) and developed a higher incidence of complete atrioventricular block following myectomy (15.4% versus 1.7%, P = 0.038).Low institutional or operator experience with ablation, uncontrollable extent and location of infarcted myocardium caused by ablation, and mitral subvalvular anomalies may be reasons for failed ASA. Surgical myectomy for the treatment of residual LVOT obstruction after unsuccessful ASA may be associated with favorable results.

A systematic review and pooled analysis of septal myectomy and edge-to-edge mitral valve repair in obstructive hypertrophic cardiomyopathy

Left ventricular outflow tract (LVOT) obstruction and systolic anterior motion (SAM) of the mitral valve (MV) occurs in 70% of hypertrophic cardiomyopathy (HCM) patients. In individuals undergoing septal myectomy, concomitant MV surgery is considered for SAM with residual LVOT obstruction or mitral regurgitation (MR); however, the optimal approach remains debated. A literature search was performed in Pubmed, EMBASE, Ovid, and the Cochrane library of published articles through June 2021 reporting on combined septal myectomy and edge-to-edge MV repair for obstructive HCM. Continuous variables were weighted and compared using a student's t-test, and categorical variables using a chi-square test with Yates correction. Six studies with 158 total patients were included. The mean follow-up was 2.8 ± 2.7 years. Compared with pre-operative values, there were significant reductions in the LV ejection fraction (69 ± 10 vs 59 ± 8%), peak LVOT gradient (82 ± 34 vs 16 ± 13 mmHg), prevalence of moderate or greater MR (84 vs 5 %), and presence of SAM (96% vs 0) (p < 0.001 for all). There was no change in LV internal diastolic diameter (4.2 ± 1.3 vs 4.4 ± 1.5 cm, p = 0.32). There were 2 (1%) operative mortalities. At follow-up, the survival rate was 97%, there were 3 (2%) re-operative MV replacements, 4 (3%) patients remained in New York Heart Association functional class III/IV, and 8 (6%) required permanent pacemaker implantation. In conclusion, combined septal myectomy and edge-to-edge MV repair is a safe and effective treatment strategy in carefully selected patients requiring surgical HCM management.

Management of Subaortic Left Ventricular Outflow Tract Obstruction After Aortic Valve Replacement

Residual or new left ventricular outflow tract (LVOT) obstruction after an aortic valve replacement poses special challenges with respect to operative techniques. Our study assesses this gap. From January 1993 to May 2019, 18 patients underwent a septal myectomy at Mayo Clinic for subaortic obstruction after aortic valve replacement. We evaluated their demographics, clinical presentation, and echocardiograms, and the type of prior valve replacement, need for repeat replacement, and their short- and long-term outcomes. The data were analyzed using descriptive statistics. All patients underwent septal myectomy for LVOT obstruction at a median interval of 7 years (interquartile range, 3-15 years) from their prior aortic valve procedure. Preoperatively, the median left ventricular outflow tract gradient was 57 mm Hg (interquartile range, 44-77 mm Hg); 10 patients (55.5%) had systolic anterior motion (SAM) of the mitral leaflets. Repeat replacement of the aortic valve at the time of myectomy was needed in 14 patients, and septal myectomy alone was performed in 4 patients. One hospital death occurred 34 days after myectomy and aortic valve replacement, and 2 patients needed permanent pacemaker placement for complete heart block. Septal myectomy after aortic valve replacement may be performed with repeat replacement of the valve, if there is coexisting prosthetic dysfunction, through a normally functioning bioprosthesis or through an apical approach when visualization through the aortic prosthesis is poor. The complexity of reoperation supports a liberal approach to myectomy at the time of aortic valve replacement when there is significant subaortic septal hypertrophy.

Edge-to-Edge Repair Versus Secondary Cord Cutting During Septal Myectomy in Patients With Hypertrophic Obstructive Cardiomyopathy: A Pilot Randomised Study

To evaluate whether the Alfieri technique improves clinical and haemodynamic results and compare it with transaortic mitral valve secondary cord cutting in patients scheduled for septal myectomy for severely symptomatic hypertrophic obstructive cardiomyopathy. Forty-eight (48) patients with moderate-to-severe systolic anterior motion (SAM)-mediated mitral regurgitation were randomly assigned to the Alfieri or Cutting groups in addition to septal myectomy. The primary endpoint was postoperative mean transmitral pressure gradient (TPG). The secondary endpoints were residual left ventricular outflow tract (LVOT) gradient after procedure, residual mitral regurgitation (MR), postoperative SAM, repeating bypass, and survival. There were no 30-day mortality and ventricular septal defects. The postoperative LVOT gradient was 15.4±7.6 mmHg and 11.1±4.9 mmHg (p=0.078) in the Alfieri and Cutting groups, respectively. The Alfieri technique was associated with higher peak (7.8±3.3 vs 4.7±2.8 mmHg; p=0.014) and mean (3.9±1.7 vs 2.1±1.6 mmHg; p=0.013) TPG. The Cutting group was associated with higher mild MR rate at discharge (six vs no patients; p=0.009). One (1) patient (4.2%) in the Alfieri group required pacemaker implantation owing to conduction disturbances (p=0.312). Two-year (2-year) freedom from late mortality and sudden cardiac death rates were 95.5%±4.4% and 100% for the Alfieri and Cutting groups, respectively (log rank, p=0.317). No patients had New York Heart Association functional class III or IV or moderate or severe MR. The maximum LVOT gradient was 20.4±15.2 mmHg and 16.7±10.4 mmHg, respectively (p=0.330). There were no reoperations during follow-up. Both techniques with septal myectomy effectively eliminated SAM-induced MR and LVOT obstructions in hypertrophic cardiomyopathy patients.

Gender Disparities in Clinical Outcome After Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy in the Chinese Han Population: A Cohort Study

Sex differences in the long-term prognosis of symptomatic hypertrophic obstructive cardiomyopathy (HOCM) patients undergoing alcohol septal ablation (ASA) remain unclear, especially in the Chinese Han population. This cohort study included 320 HOCM Chinese Han patients who underwent ASA because of symptomatic left ventricular outflow tract (LVOT) obstruction. Patients were grouped according to sex: females (mean±standard deviation age [SD] 50.7±6.8 years) and males (mean±SD age 52.6±7.3 years). Individuals were followed over the long term. Pre-procedure, women had more symptoms (New York Heart Association [NYHA] class III-IV 67.3% vs 56.3%, p=0.03), more atrial fibrillation (23.5% vs 14.6%, p=0.047) than men. Transient complete atrioventricular block after ASA was more common in woman than in men (34.0 vs 23.4%; p=0.048). Residual LVOT gradient, post-procedural residual left ventricular wall thickness, NYHA functional class, and adverse arrhythmic events were comparable between the two groups. The 10-year survival rate (77% vs 89%, p=0.037) and the annual adverse arrhythmic event rate (1.3% vs 0.4%, p<0.01) following ASA were significantly worse in women compared with men. Kaplan-Meier analysis showed a significantly lower survival in women compared with men (p=0.023). In multivariable modelling, female sex remained independently associated with higher all-cause mortality (hazard ratio, 1.12; 95% confidence interval, 1.08-1.27; p=0.03) when adjusted for age, NYHA class III-IV symptoms, and other cardiovascular comorbidities. Female patients with HOCM undergoing ASA tended to have more severe symptoms and adverse arrhythmic events. The 10-year survival rate after ASA was significantly worse in women compared with men with HOCM. Sex may need to be considered as an important factor in the clinical management of patients with symptomatic HOCM.

Importance of surgical expertise in septal myectomy for obstructive hypertrophic cardiomyopathy.

In 2011, a multidisciplinary hypertrophic cardiomyopathy (HCM) program with a dedicated myectomy surgeon was implemented at our institution. We hypothesized that a dedicated approach allows better identification and management of mitral regurgitation (MR) during septal myectomy (SM) for obstructive HCM with significant mitral regurgitation. Between 2006 and 2018, 181 patients had SM at our institution. This study consists of 53 patients with preoperative moderate or greater MR associated with systolic anterior motion who underwent isolated SM with or without mitral intervention. Patients were divided into those who underwent SM by a dedicated myectomy surgeon (group D, n = 31) or by a non-dedicated surgeon (group ND, n = 22). Primary outcome of interest was rate of mitral valve replacement (MVR) at SM. Secondary outcomes include in-hospital mortality, need for permanent pacemaker, mitral valve reoperation, and residual MR and left ventricular outflow tract gradient on postoperative echocardiography. 12 patients (55%) had a concomitant MVR during septal myectomy in group ND compared to 2 patients (6%) in group D (p < 0.01). Among patients who did not undergo MVR, patients in group D less commonly had residual MR than patients in ND after SM (p < 0.01). Group D had 100% survival with NYHA class I in 94% patients at follow-up visit (p = 0.01). Reoperation for MVR was required in four patients in group ND vs. none in group D (p < 0.01). A dedicated surgeon is able to spare the mitral valve in patients undergoing SM. This study emphasizes the importance of surgical expertise in this cohort.

Alcohol septal ablation in patients with severe septal hypertrophy

ObjectiveThe current guidelines suggest alcohol septal ablation (ASA) is less effective in hypertrophic obstructive cardiomyopathy (HOCM) patients with severe left ventricular hypertrophy, despite acknowledging that systematic data are lacking. Therefore,...

Septal Myectomy With Vs Without Subvalvular Apparatus Intervention in Patients With Hypertrophic Obstructive Cardiomyopathy: A Prospective Randomized Study

Surgical septal myectomy is a standard treatment option for patients with hypertrophic obstructive cardiomyopathy. Subvalvular abnormalities of the mitral valve might play an important role in residual left ventricular outflow tract obstruction. This randomized study aimed to compare the surgical outcomes of septal myectomy with vs without subvalvular interventions. Between July 2015 and December 2016, 80 eligible patients were randomly assigned to undergo septal myectomy with vs without subvalvular intervention. The peak gradient was 92.3 ± 16.9 and 88.1 ± 15.4 mm Hg, respectively (P = 0.281). The mean septum thickness was 26.8 ± 4.5 and 26.1 ± 4.2 mm, respectively (P = 0.504). Moderate or severe systolic anterior motion syndrome-mediated mitral regurgitation was observed in all patients. There was no residual mitral regurgitation in the group with subvalvular intervention, while 15% of patients in the control group had regurgitation (P = 0.013). Residual systolic anterior motion syndrome was observed in 5% and 27.5% of patients, respectively (P = 0.007). The median postoperative gradient was 13 (interquartile range 9-16) mm Hg and 8 (interquartile range 4-12) mm Hg, respectively (P = 0. 0.019). At the 12-month follow-up, all patients were alive. There were 87.5% vs 77.5%, and 12.5% vs 22.5% of patients categorized as having New York Heart Association functional classes I and II, respectively (P = 0.378). The prevalence rate of residual mitral regurgitation was 10% and 32.5%, respectively (P = 0.010). Concomitant subvalvular intervention during septal myectomy more effectively eliminates left ventricular outflow tract obstruction, providing better freedom from residual mitral regurgitation without clinical benefit 1 year after surgery.

SEPTAL MYECTOMY WITH SUBVALVULAR APPARATUS INTERVENTION IN PATIENTS WITH HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY: IMMEDIATE RESULTS

Aim. Surgical septal myectomy is a standard treatment option for patients with hypertrophic obstructive cardiomyopathy. Subvalvular abnormalities of the mitral valve may play an important role in residual left ventricular outflow tract obstruction. This study aimed to evaluate the surgical outcomes of septal myectomy with subvalvular interventions.Material and Methods. Between July, 2015 and December, 2016, 40 eligible patients underwent septal myectomy with subvalvular intervention. The peak gradient was 92.3±16.9 mm Hg. The mean septum thickness was 26.8±4.5 mm. Moderate or severe systolic anterior motion syndrome-mediated mitral regurgitation was observed in all patients.Results. There was no residual mitral regurgitation. Residual systolic anterior motion syndrome was observed in 5%. The postoperative gradient was 8.7±4.5 mm Hg. At 12-month follow-up, all patients were alive. According to the New York Heart Association (NYHA) classification, 87.5 and 12.5% of patients had NYHA functional classes I and II, respectively. The prevalence rate of residual mitral regurgitation was 10%.Conclusions. Concomitant subvalvular intervention during septal myectomy effectively eliminated left ventricular outflow tract obstruction and provided high freedom from residual mitral regurgitation one year after surgery.

Intraoperative transesophageal echocardiographic predictors of recurrent left ventricular outflow tract obstruction in children undergoing subaortic stenosis resection.

Intraoperative transesophageal echocardiography (iTEE) is used to assess for residual left ventricular outflow tract obstruction (LVOTO) after surgical resection of subaortic membrane causing subaortic stenosis (sub-AS). We aimed to identify the iTEE features associated with recurrence of LVOTO. We conducted a retrospective study of children undergoing sub-AS resection from June 2006 to June 2014. Doppler assessment of the flow velocity and the anatomical features of the left ventricular outflow tract were analyzed from stored echocardiograms. Recurrent LVOTO was defined as an increase in the mean pressure gradient across the left ventricular outflow tract of > 15mmHg on the most recent follow-up echocardiogram from the mean pressure gradient on the predischarge echocardiogram or as doubling of the mean pressure gradient to a value ≥20mmHg. Thirty-five patients were included, with median age at surgery was 8.1 years (range: 0.7-29 years) and median follow-up was 47 months (2-91 months). Ten patients (29%) had recurrent LVOTO, which was associated with a shorter distance between the narrowest diameter of the outflow tract and the aortic valve on iTEE [median 0.59 cm (range 0.39-0.74) vs 0.98 cm (0.75-1.5), P=.03]. No patients with more than mild residual LVOTO on iTEE regressed to mild or no LVOTO on follow-up echocardiograms. LVOTO recurrence after sub-AS resection is common, and residual LVOTO remains the same or increases over time. Proximity of the LVOTO to the aortic valve is a risk factor for recurrent LVOTO. These findings may be useful in counseling patients and to guide the frequency of postoperative follow-up.

2-Year Outcomes After Transcatheter Mitral Valve Replacement

ObjectivesThis study sought to determine late (2-year) outcomes following transcatheter mitral valve replacement (TMVR) with the FORTIS valve (Edwards Lifesciences, Irvine, California). BackgroundNo data exist on long-term clinical outcomes following TMVR in patients with severe native mitral regurgitation (MR). MethodsThis multicenter registry included consecutive patients with severe MR who underwent TMVR with the FORTIS valve under a compassionate clinical use program. Clinical and echocardiographic data were collected at baseline, 30-day, and 1- and 2-year follow-up. ResultsThirteen patients (71 ± 8 years, 10 men, logistic European System for Cardiac Operative Risk Evaluation score = 23.7 ± 12.1%) with severe MR were included. MR was of ischemic origin in most (76.9%) patients, and the mean left ventricular ejection fraction was 34 ± 9%. Technical success was achieved in 10 patients (76.9%), and 5 patients (38.5%) died within the 30 days following the procedure. At 30-day follow-up, mean transmitral gradient was 3 ± 1 mm Hg, and there were no cases of moderate-severe residual MR or left ventricular outflow tract obstruction. Two patients died during the follow-up period due to terminal heart failure, leading to an all-cause mortality rate of 54% at 2-year follow-up. At 2-year follow-up, all patients but 1 were in New York Heart Association functional class II, and there were no cases of valve malfunction (increasing gradients or MR recurrence). Computed tomography exams performed at 2-year follow-up in 3 patients showed no valve prosthesis fractures or displacement. ConclusionsTMVR with the FORTIS valve was feasible. MR reduction after TMVR was maintained at 2-year follow-up and no late device-related events were observed.

Outcomes of Alcohol Septal Ablation in Younger Patients With Obstructive Hypertrophic Cardiomyopathy

ObjectivesThe aim of this study was to describe the safety and outcomes of alcohol septal ablation (ASA) in younger patients with obstructive hypertrophic cardiomyopathy. BackgroundThe American College of Cardiology Foundation/American Heart Association guidelines reserve ASA for older patients and patients with serious comorbidities. Data on long-term age-specific outcomes after ASA are scarce. MethodsA total of 1,197 patients (mean age 58 ± 14 years) underwent ASA for obstructive hypertrophic cardiomyopathy. Patients were divided into young (≤50 years), middle-age (51 to 64 years), and older (≥65 years) groups. ResultsThirty-day mortality and pacemaker implantation rates were lower in young compared with older patients (0.3% vs. 2% [p = 0.03] and 8% vs. 16% [p < 0.001], respectively). Ninety-five percent of young patients were in New York Heart Association functional class I or II at last follow-up. During a mean follow-up period of 5.4 ± 4.2 years, 165 patients (14%) died. Annual mortality rates of young, middle-age, and older patients were 1%, 2%, and 5%, respectively (p < 0.01). Annual adverse arrhythmic event rates were similar in the 3 age groups at about 1% (p = 0.90). Independent predictors of mortality in young patients were age, female sex, and residual left ventricular outflow tract gradient. Additionally, young patients treated with ≥2.5 ml alcohol had a higher all-cause mortality rate (0.6% vs. 1.4% per year in patients treated with <2.5 ml, p = 0.03). ConclusionsASA in younger patients with obstructive hypertrophic cardiomyopathy was safe and effective for relief of symptoms at long-term follow-up. The authors propose that the indication for ASA can be broadened to younger patients.