Residual Left Ventricular Outflow Tract Obstruction Research Articles

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.

Outcomes of Alcohol Septal Ablation in Patients With Severe Left Ventricular Outflow Tract Obstruction: A Propensity Score Matching Analysis.

The current ACC/AHA guidelines on hypertrophic cardiomyopathy (HCM) caution that alcohol septal ablation (ASA) might be less effective in patients with left ventricular outflow tract obstruction (LVOTO) ≥ 100 mm Hg. We used a multinational registry to evaluate the outcome of ASA patients according to baseline LVOTO. A total of 1346 ASA patients were enrolled and followed for 5.8 ± 4.7 years (7764 patient-years). The patients with baseline LVOTO ≥ 100 mm Hg were significantly older (61 ± 14 years vs 57 ± 13 years; P < 0.01), more often women (60% vs 45%; P < 0.01), and had a more pronounced HCM phenotype than those with baseline LVOTO < 100 mm Hg. There were no significant differences in the occurrences of 30-day major cardiovascular adverse events in the 2 groups. After propensity score matching (2 groups, 257 pairs of patients), the long-term survival was similar in both groups (P= 0.10), the relative reduction of LVOTO was higher in the group with baseline LVOTO ≥ 100 mm Hg (82 ± 21% vs 73 ± 26%; P < 0.01), but the residual resting LVOTO remained higher in this group (23 ± 29 mm Hg vs 13 ± 13 mm Hg; P < 0.01). Dyspnoea (NYHA functional class) at the most recent clinical check-up was similar in the 2 groups (1.7 ± 0.7 vs 1.7 ± 0.7; P= 0.85), and patients with baseline LVOTO ≥ 100 mm Hg underwent more reinterventions (P= 0.02). After propensity matching, ASA patients with baseline LVOTO ≥ 100 mm Hg had similar survival and dyspnoea as patients with baseline LVOTO < 100 mm Hg, but their residual LVOTO and risk of repeated procedures were higher.

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.

Effectiveness of alcohol septal ablation for hypertrophic obstructive cardiomyopathy in patients with late gadolinium enhancement on cardiac magnetic resonance

BackgroundAccording to European guidelines, alcohol septal ablation (ASA) for hypertrophic obstructive cardiomyopathy (HOCM) may be less effective in patients with extensive septal scarring on cardiac magnetic resonance (CMR). This study aimed to analyze the impact of late gadolinium enhancement (LGE) on CMR on the effectiveness of ASA. MethodWe conducted an observational retrospective study involving adult patients with symptomatic drug-refractory HOCM who underwent CMR before ASA at two European centres from May 2010 through June 2019. Patients were compared in binary format based on LGE presence. Moreover, a subanalysis focused on patients with septal fibrosis was performed. The effectiveness of ASA was evaluated by echocardiographic, ECG and clinical findings. ResultsOf the 113 study patients, 54 (48%) had LGE on CMR. The LGE quantification performed in 29 patients revealed septal fibrosis in 17. The mean follow-up was 4.4 ± 2.6 years. Baseline parameters were similar between groups except for basal septal thickness that was greater in LGE+ group (21.1 ± 3.9 mm for LGE+ vs. 19.2 ± 3.2 mm for LGE-: p = .005). ASA improved symptoms in all groups and reduced left ventricular outflow tract obstruction (LVOTO) (delta gradient reduction: LGE+: 62 ± 37.3%; septal LGE+: 75.6 ± 20.8%; LGE-: 72.5 ± 21.0%). However, 13% of the LGE+ and 2% of the LGE- group had residual LVOTO above 30 mmHg (p = .027). ConclusionASA was effective in all patients with HOCM, whether they had LGE on CMR or not and whether they had septal fibrosis or not.

Modified Ross-Konno procedure in children: subcoronary implantation technique with Konno incision for annular and subannular hypoplasia.

The technique of subcoronary autograft implantation for the Ross procedure has shown excellent durability of aortic valve function in adults. However, its use in children with hypoplastic aortic annulus or multilevel left ventricular outflow tract obstruction (LVOTO) was traditionally precluded. We combined this technique with a Konno incision and evaluated LVOTO relief and durability of the autograft function in growing patients. Between January 2012 and January 2017, 13 patients with severe LVOTO and hypoplastic aortic annulus underwent Ross-Konno procedure with subcoronary autograft implantation. The median age at operation was 14 months. Six were infants. Concomitant procedures included resection of endocardial fibroelastosis (n = 9), mitral valvuloplasty (n = 2) and aortic arch repair (n = 1). The Konno incision was enlarged with a patch. The autograft was implanted beneath the ostia of the coronary arteries, retaining external support by the native aortic annulus. A newborn with hypoplastic left heart complex and Turner syndrome died in hospital: early mortality of 7.7%. No residual LVOTO or autograft regurgitation was observed at discharge. At a median follow-up of 20 months, no death had occurred. No catheter or surgical reintervention on the aortic valve or any LVOT site was needed. All peak pressure gradients across the LVOT were <10 mmHg. No autograft regurgitation was detected. The Ross procedure using subcoronary implantation technique combined with LVOT Konno enlargement is feasible even in patients with multilevel LVOTO and marked size discrepancy between the autograft and native aortic annulus. Longer follow-up is indicated to confirm the expected durability of the autograft function.

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.

Predictors of Outcome After Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy: An Echocardiography and Cardiovascular Magnetic Resonance Imaging Study.

Alcohol septal ablation (ASA) is used for treatment of medically refractory hypertrophic obstructive cardiomyopathy patients with severe left ventricular outflow tract (LVOT) obstruction. The current recommendations restrict the procedure to adults with favorable anatomy and no other coexisting surgically amenable disease. Some patients remain symptomatic with residual LVOT obstruction, thus better patient selection is required. One-hundred and two consecutive subjects with hypertrophic obstructive cardiomyopathy who underwent cardiovascular magnetic resonance imaging, transthoracic echocardiography, and ASA were enrolled in this study. Successful ASA was defined as reduction of LVOT gradient ≥50% of baseline by echocardiographic follow-up 6 months post ASA. The relationships between segmental thickness assessed by cardiovascular magnetic resonance imaging and echocardiography and outcomes of ASA were compared between the 2 groups. The survival rate after ablation was 100% at 6-month follow-up. The LVOT gradient decreased ≥50% of baseline in 72% (73/102) patients. There were good correlations between the reduction of postoperative LVOT gradient and the thickness of basal anterior segment (r=0.371; P<0.001), basal anteroseptal segment (r=0.527; P<0.001), and total thickness of the above 2 segments (r=0.672; P<0.001). The area under the receiver operating curves were 0.68, 0.79 and 0.89 for predictive analysis (all P<0.001). The cutoff thickness of the segment 1+2 was 50.9 mm, which yielded a sensitivity of 86% and specificity of 77%. Both echocardiography and cardiovascular magnetic resonance imaging can be used effectively as noninvasive tools for patient selection for ASA procedure. A significantly thickened septum among hypertrophic obstructive cardiomyopathy patients may be associated with a poor outcome after ASA.

Rescue alcohol septal ablation in sepsis with multiorgan failure

A 55 year old male patient with a diagnosis of hypertrophic cardiomyopathy was admitted with features of sepsis related to cholangitis. Initial management with intravenous (i.v.) fluids and antibiotics did not cause any change in his general condition mandating an emergency endoscopic retrograde cholangio-pancreatography (ERCP). After successful retrieval of CBD stone on ERCP, patient had massive upper gastrointestinal bleed leading to hypotension and shock. Addition of inotropes had led to further deterioration in his clinical status with a mean arterial BP falling to 44 mm of Hg. His echocardiography showed a resting left ventricular outflow tract (LVOT) gradient of 90 mm of Hg and thus was taken up for emergency alcohol septal ablation (ASA). Immediately after ASA, patient had significant decrease in LVOT obstruction and rise of systemic arterial pressures. After 10 days of antibiotic therapy patient was discharged with a residual LVOT obstruction of 28 mm of Hg.

Surgical Management of Left Ventricular Outflow Tract Obstruction

Left ventricular outflow tract obstruction (LVOTO) is caused by a spectrum of lesions. This study was performed to determine the outcomes of surgical management of LVOTO. All patients who had surgery of the LVOT between 2002 and 2010 were retrospectively reviewed. There were 103 consecutive patients with median age 6.8 years (range 8 days to 62 years). Fourteen patients had simple subaortic membrane. Eighty-nine patients had complex LVOTO including fibromuscular obstruction (n = 53), tunnel obstruction (n = 22), hypertrophic cardiomyopathy/muscular obstruction (n = 15), and anomalies of the mitral subvalvar apparatus (n = 13). There were no early deaths. Mean LVOT gradient decreased from 33 mmHg (range 1 to 108 mmHg) to 6 mmHg (range 0 to 45 mmHg) (p < 0.001). Median follow-up was 3.8 years (range 0.9 to 8.5 years). There were three late deaths. Cumulative survival at one, three, and five years was 96% (95% CI 89% to 99%). All patients are in New York Heart Association classes I-II. Ten patients required reoperation (three for recurrent/residual LVOTO). Freedom from reoperation was 94%, 90%, and 78% at one, three, and five years (95% CI 86% to 98%, 80% to 95%, and 59% to 89%, respectively). No patient with complex LVOTO who had release of the fibrous trigones required reoperation [0% (0/26) vs. 16% (10/63) (p = 0.031)]. Factors associated with increased reoperation risk were interrupted aortic arch (OR 6.4, p = 0.22), atrioventricular septal defect (OR 15.4, p = 0.008), and higher mean LVOT gradient at discharge (OR 1.08, p = 0.023). Utilizing a multitude of operative strategies for surgery of the LVOT results in favorable early and midterm outcomes. Residual LVOTO and original cardiac diagnosis are associated with increased reoperation risk. Release of the fibrous trigones decreases reoperation risk in patients with complex LVOTO.

Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy in Pediatric Patients: Early and Late Results

Symptomatic pediatric patients with obstructive hypertrophic cardiomyopathy (HCM) have a higher death rate (6% annually) compared with adults. Transaortic left ventricular septal myectomy provides excellent outcomes for adults with obstructive HCM. We sought to assess the effect of septal myectomy on late survival and outcome in pediatric patients with obstructive HCM. From 1975 to 2003, 56 pediatric patients underwent septal myectomy for obstructive HCM. Mean age at diagnosis was 6.3 +/- 5.4 years. Ages at operation ranged from 2 months to 20 years (mean 11 +/- 5.6 years). Concomitant procedures included mitral valve repair (n = 7), closure of atrial septal defect (n = 3), and other (n = 5). After myectomy, mean left ventricular outflow tract (LVOT) gradient decreased from 103 +/- 34 to 16 +/- 12 mm Hg and mean degree of mitral regurgitation decreased from 2.0 +/- 1.0 to 1.0 +/- 0.3 (both p < 0.0001). There were no early deaths. Four patients underwent elective cardioverter defibrillator implantation and 1 patient received a permanent pacemaker. Follow-up ranged up to 29 years (mean, 8.6 +/- 6.2). Cardiac reoperations were required in 8 patients: heart transplantation (n = 2), repeat myectomy (n = 2), mitral valve repair-replacement (n = 2), Konno-Rastan procedure (n = 1), and aortic valve replacement (n = 1). Age 14 years or less at operation was the only predictor of late reoperation (p = 0.017). Two patients died late; one suddenly without residual LVOT obstruction and one from chronic rejection after heart transplantation. Ninety-six percent of surviving patients were in New York Heart Association functional class I or II. Survival estimates at 5 and 10 years were 97% and 93%, respectively. Septal myectomy is safe and effective in symptomatic pediatric patients with obstructive HCM. Late survivorship compares very favorably with the natural history of this disease.

Surgery for aortic stenosis in children: a 40-year experience

Background Aortic stenosis (AS) is encountered in approximately 5% of children with heart disease. The indications for surgery and the surgical techniques for AS are well established. This report focuses on the early and long-term outcomes in children with AS over a 40-year period. Methods Included in this study were 508 patients ranging in ages from 1 day to 19 years, who were operated on for AS between 1960 and 2002 . Eighty-one percent (414 of 508) of the patients had left ventricular outflow tract obstruction (LVOTO) at a single level: 40 supravalvar, 242 valvar (critical AS in 85 neonates and young infants and in 157 older children), and 132 subvalvar. Nineteen percent (94 of 508) of the patients had LVOTO at more than one level. Associated congenital cardiac defects were found in 32% of the patients. Results The overall hospital mortality rate was 8% (40/508) with neonates with critical AS having the highest mortality (33%). The late mortality was 4% for the entire group. Follow-up was 95% complete. The mean follow-up was 8.5 ± 7.1 years. In the subgroup with multilevel LVOTO (n = 94), the average intraoperative peak systolic left ventricular-aortic gradient decreased from 80 to 22 mm Hg after repair but increased progressively to 74 ± 36 mm Hg ( p < 0.05) before reintervention was required. One hundred twenty-one patients (24%) underwent 151 reoperations for recurrent or residual LVOTO or aortic regurgitation. Actuarial curves predict a 20-year survival of 88% and 62% freedom from reoperation for all patients with AS. Symptomatic improvement in survivors was excellent (90% New York Heart Association class I). Conclusions Surgical relief of LVOTO in infants and children can be accomplished with low mortality and morbidity. Neonates with critical AS have significantly higher mortality and morbidity due to their complex anatomy and their critical presentation that affects outcome. Aortic valvotomy delays valve replacement in a significant percentage of children. The Ross procedure and mechanical aortic valve replacements have had a low mortality and morbidity in our series. Valve replacement will eventually be required in most children presenting with valvar AS and multilevel LVOTO while repair of discrete subaortic stenosis and supravalvar AS may not require reoperation in most patients. Children with LVOTO should have lifetime follow-up.

Echocardiographic assessment of obstructive lesions in atrioventricular septal defects

OBJECTIVESWe sought to determine the accuracy of transthoracic echocardiography (TTE) in identifying risk factors in patients with an atrioventricular septal defect (AVSD).BACKGROUNDAtrioventricular septal defect is a common lesion, and many decisions about it are based on echocardiography alone. The identification of associated left-sided inflow and outflow obstructive lesions is important, as they are responsible for mortality and morbidity.METHODSBetween 1983 to 1998, 549 patients with AVSD underwent repair. The TTE findings were correlated with surgery, angiocardiography, autopsy or postoperative TTE. Papillary muscle measurements were made in those with either a left ventricular outflow tract (LVOT) or left ventricular inflow abnormality and compared with those measurements from control subjects. Measurements of the LVOT were made in patients with an identified LVOT abnormality.RESULTSThere were 63 missed lesions, decreasing over time. Double-orifice left atrioventricular valve (DOLAVV) and nonobstructive chordae in the LVOT were more often missed. Re-operation was performed to address a missed lesion in 2 of 68 patients. Two of 55 patients died of reasons related to a missed lesion. In 67% of patients, DOLAVV was missed. Abnormal papillary muscle angles were seen with either a LVOT abnormality or DOLAVV. High insertion of the anterolateral papillary muscle was a risk factor for death or residual LVOT obstruction. Abnormal LVOT measurements were found in patients with tunnel obstruction and those with an acquired subaortic ridge.CONCLUSIONSTransthoracic echocardiography provides accurate preoperative information on AVSD.

Surgical experience with left ventricular outflow tract obstruction in patients with complete transposition of the great arteries and essentially intact ventricular septum undergoing the Mustard operation.

During a 24-year period (1963-1987), 46 infants and children with complete transposition of the great arteries (CTGA) and an essentially intact ventricular septum (IVS) have undergone surgical relief of left ventricular outflow tract obstruction (LVOTO) concurrently with the Mustard operation (MO). The obstruction was valvar in 2 patients, subvalvar in 43 and combined valvar and subvalvar in 1; the ventricular septum was intact in 42, and 4 patients had a small VSD at the time of repair. Neonatal and pre-Mustard cardiac catheterization (CC) data were analyzed to obtain LV to right ventricular peak systolic pressure ratio (LV/RVPSP) and LVOT peak systolic gradient (PSG). The mean neonatal LV/RVPSP (n = 31) was 0.79 +/- 0.04; pre-Mustard LV/RVPSP (n = 44) was 0.75 +/- 0.05; pre-Mustard LVOT PSG (n = 34) was 46.5 +/- 3.5 mmHg. Neonatal (n = 29) and pre-Mustard (n = 30) cardiac angiograms were retrospectively reviewed to analyse morphologic substrates of LVOTO. In the neonatal period, LVOTO was present in 7 patients (anatomic, n = 4; dynamic, n = 2; combined, n = 1). Immediately prior to the MO, LVOTO was present in 29 (anatomic, n = 20; dynamic n = 2; combined, n = 7). Techniques to correct LVOTO at the initial MO included pulmonary valvotomy (n = 3), ventriculomyectomy (n = 41), resection of an windsock aneurysm (n = 1), LV to pulmonary artery valved conduit (VC) (n = 1). Two patients underwent VC early postoperatively (PO) for severe residual LVOTO (both died).(ABSTRACT TRUNCATED AT 250 WORDS)

Operative Treatment of Congenital Aortic Stenosis

The operative treatment of 131 patients with congenital aortic stenosis is reviewed. Of the 131 patients, 77% had left ventricular outflow tract (LVOT) obstruction at a single level and 23%, major obstruction at more than one level. There were 3 operative deaths (2.3%) and 10 late deaths (7.8%). Twenty of the 128 discharged patients have undergone a second procedure and 6 a third procedure for recurrent or residual LVOT obstruction. The 26 reoperations included 7 aortic valve replacements, 4 left ventricular apical-abdominal aortic (LV-AA) valved conduits, and 15 extensive aortic valvotomies with or without supravalvular aortoplasty. Five of the 20 patients undergoing reoperation died; 4 of these deaths occurred in patients who had valve replacement at reoperation. The 4 who received LV-AA conduits have sustained excellent hemodynamic and clinical results with no complications. Highly satisfactory clinical results can be obtained with minimal operative risk, regardless of the level of LVOT obstruction. Reoperation for recurrent or residual LVOT obstruction, however, is comparatively more hazardous, and alternative surgical approaches (LV-AA conduits) should be considered.