Septal Myectomy For Hypertrophic Obstructive Cardiomyopathy Research Articles

Extended septal myectomy for obstructive hypertrophic cardiomyopathy and its impact on mitral valve function.

Septal myectomy is the treatment of choice for hypertrophic obstructive cardiomyopathy (HOCM). Around 30-60% of patients with HOCM have a secondary mitral valve regurgitation due to systolic anterior motion (SAM). We report our experience with extended septal myectomy and its impact on the incidence of concomitant mitral valve procedures. This is a retrospective study on 84 patients who underwent SM from January 2008 to February 2022. Surgical procedure was performed according to the concept of 'extended myectomy' described by Messmer in 1994. Follow-up outcomes in terms of survival, hospital admissions for heart failure or MV disease, cardiac reoperations, and pacemaker (PMK) implantation were recorded. Mean age was 61 ± 15 years. Mitral valve surgery was performed in seven cases (8%); particularly only one patient without degenerative mitral valve disease underwent mitral valve surgery, with a plicature of the posterior leaflet. In-hospital mortality was 5%. Mitral valve regurgitation greater than mild was present in four patients (5%) at discharge. Twelve-year survival was 78 ± 22%. Cumulative incidence of rehospitalization for heart failure and rehospitalization for mitral valve disease was 10 ± 4 and 2.5 ± 2.5%, respectively. PMK implantation was 5% at discharge, with a cumulative incidence of 15 ± 7%. Freedom from cardiac reoperations was 100%. Septal myectomy for HOCM is associated with good outcomes. Although concomitant surgery on the mitral valve to address SAM and associated regurgitation has been advocated, these procedures were needed in our practice only in patients with intrinsic mitral valve disease. Adequate myectomy addresses the underlying pathophysiology in most patients.

Improvement in Sexual Dysfunction in Patients With Hypertrophic Cardiomyopathy Undergoing Septal Myectomy: A Prospective Study

BackgroundSeptal myectomy improves symptoms in the majority of patients with obstructive hypertrophic cardiomyopathy (HCM), but there are limited prospective data on functional outcomes after operation. ObjectivesThe authors investigated quality of life measures and prevalence of sexual dysfunction before and after septal myectomy for obstructive HCM. MethodsBetween January 2018 and October 2019, 436 patients underwent transaortic septal myectomy at our clinic. All patients were screened for eligibility, and 197 (45.2%) were enrolled in this prospective survey study. Patients received a questionnaire pertaining to quality of life and sexual health before and within 4 to 6 months postoperatively, and 113 (57.4%) completed the follow-up survey. ResultsThe mean age of the 54 (47.8%) women and 59 (52.2%) men was 54.7 ± 14.1 years. Quality of life, including both mental and physical components, improved significantly in both men (P < 0.001) and women (P < 0.001). Women reported mild sexual dysfunction at baseline, and following septal myectomy, they experienced significant (P < 0.05) improvement in most domains pertaining to sexual health. In men, the International Index of Erectile Function median score was 23 (IQR: 7.0-29.5), which is consistent with mild dysfunction at baseline, and there was significant improvement following surgery in young (age ≤55 years) men (P < 0.001). ConclusionsQuality of life is significantly improved following septal myectomy in patients with obstructive HCM. Both women and men reported mild sexual dysfunction at baseline, and women and younger men (age ≤55 years) experienced significant improvements in sexual health.

Quantitative Assessment of Three-Dimensional Aorto-Mitral Angle in Hypertrophic Cardiomyopathy

BackgroundThis study explored the correlation between the 3-dimensional aorto-mitral angle and pressure gradients in patients with obstructive hypertrophic cardiomyopathy (HCM) undergoing septal myectomy, with or without aortic shortening. MethodsA single-site, retrospective observational study was conducted at a tertiary-level hospital; 67 patients underwent septal myectomy for obstructive HCM. Preoperative and postoperative transesophageal images were analyzed offline to measure the end-systolic 3-dimensional aorto-mitral angle with Mitral Valve Quantification software and Doppler-derived pressure gradients. The angle’s impact on pressure gradients after myectomy, with or without aortic shortening, was evaluated by linear regression. ResultsRegression analysis found no significant relationship between aorto-mitral angle changes and postmyectomy pressure gradients (r = 0.03; 95% CI, −0.22 to 0.28; P = .81), regardless of aortic shortening. No major angle differences were observed between myectomy-only patients and those with additional aortic shortening (97.0° ± 8.4° vs 100.4° ± 8.7°; P = .78). ConclusionsThe reduced angle seen in patients with obstructive HCM did not return to normal values after septal myectomy, even with normalized pressure gradients. Aortic shortening did not significantly influence the aorto-mitral angle after myectomy either.

Posterior Wall Thickness Associates With Survival Following Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy

BackgroundThe left ventricular (LV) posterior wall thickness (PWT) is a predictor of sudden cardiac death in pediatric patients with hypertrophic cardiomyopathy (HCM), but the prognostic importance of PWT in adults has not been examined. ObjectivesThe goal of this study was to evaluate the association of LV PWT with late survival in adult patients undergoing septal myectomy for obstructive HCM. MethodsThis single-center study reviewed 2,418 patients who underwent transaortic septal myectomy for obstructive HCM. ResultsThe median preoperative PWT was 13 (IQR: 11-15) mm. Patients with PWT >13 mm tended to have systemic hypertension (55.4% vs 49.1%; P = 0.002) and a larger body mass index (median: 30.8 [IQR: 27.1-35.1] kg/m2 vs 29.6 [IQR: 26.1-33.9] kg/m2; P < 0.001). Preoperatively, PWT >13 mm was associated with increased septal thickness (median: 21 [IQR: 18-24] mm vs 19 [IQR: 17-22] mm; P < 0.001), greater maximum instantaneous left ventricular outflow tract (LVOT) gradient at rest (median: 67 [IQR: 36-96] mm Hg vs 47 [IQR: 19-79] mm Hg), and increased likelihood of moderate or greater mitral valve regurgitation (54.3% vs 47.3%; P = 0.001). However, PWT was not related to the severity of limitations measured by New York Heart Association functional class (P = 0.674). After adjusting for baseline covariates, greater PWT was an independent risk factor for late mortality after septal myectomy (P = 0.003). ConclusionsPWT is a newly identified predictor of reduced long-term survival after septal myectomy that is independent of septal thickness and severity of LVOT gradient. Future studies are warranted to investigate the mechanisms underlying the association and the potential usefulness of PWT in patient management.

Preoperative left ventricular longitudinal strain predicts outcome of septal myectomy for obstructive hypertrophic cardiomyopathy

ObjectiveThe objective of this study was to determine the characteristics of longitudinal strain and its effect on outcomes in patients with obstructive hypertrophic cardiomyopathy (HCM) who underwent septal myectomy. MethodsWe reviewed patients with obstructive HCM who underwent septal myectomy at our clinic from 2007 to 2016. Data of those who had strain echocardiography within 6 months before isolated myectomy were analyzed. ResultsThe median age of the 857 patients studied was 55 (interquartile range [IQR], 44-63) years, and 451 (52.6%) were male. Left ventricular ejection fraction was 71% (IQR, 67%-74%), and the resting peak outflow tract gradient was 58 (IQR, 27-85) mm Hg. The median global longitudinal strain (GLS) was −14.6% (IQR, −12.0% to −17.3%). Regional longitudinal strain was nonuniform as reflected by more normal values in apical segments and more abnormal in basal segments. Moreover, GLS correlated poorly with ejection fraction and outflow tract gradient. In 64 patients who had postoperative strain echocardiography, GLS was comparable before and after septal myectomy, but regional strain was more uniform after myectomy. Over a follow-up of 8.3 (IQR, 6.5-10.3) years, when patients were equally stratified according to GLS (cutoff, −14.64%), the group with worse GLS had significantly poorer survival compared with the better GLS group (P = .002). Left ventricular ejection fraction had no association with survival. ConclusionsLeft ventricular longitudinal strain is nonuniform and might be significantly reduced in patients with obstructive HCM. Septal myectomy does not impair GLS but is associated with more uniform regional strains. Most importantly, reduced GLS preoperatively is strongly and independently associated with increased all-cause mortality after septal myectomy for obstructive HCM.

Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy in the Elderly

BackgroundHypertrophic obstructive cardiomyopathy is a genetic disorder treated with septal reduction therapy, either alcohol septal ablation or septal myectomy (SM). Historically older patients have been presumed to be poor candidates for SM and thus referred directly for alcohol septal ablation in some centers. We reviewed our experience with SM in older patients. MethodsWe identified 100 patients at our institution who underwent SM for hypertrophic obstructive cardiomyopathy from 2015 to 2020. Demographic and clinical characteristics and outcomes of patients 65 years or older were compared with patients younger than 65. ResultsSixty-five patients were in the <65 group and 35 patients in the ≥65 group. Both groups had similar preoperative peak stress left ventricular outflow tract gradients (129 mm Hg vs 110 mm Hg, P < .001). Most patients in both groups had moderate to severe mitral regurgitation on preoperative stress echocardiography. The elderly group was more likely to have coronary artery bypass graft as a concomitant procedure (37% vs 8%, P < .001). Only 1 death occurred in the series secondary to a pulmonary embolism. At the 30-day follow-up on stress echocardiography, peak stress gradients were normal in both groups (21 and 20 mm Hg, respectively; P < .001), and 88% of all patients had trace to mild mitral regurgitation. ConclusionsProperly selected older patients can safely undergo SM with excellent outcomes similar to younger patients. Relief of left ventricular outflow tract obstruction and correction of mitral regurgitation are reliably achieved in both groups. Advanced age should not be a strict criteria for selecting septal reduction therapy approach.

Hypertrophic obstructive cardiomyopathy: the Mayo Clinic experience.

Hypertrophic cardiomyopathy (HCM) is a primary myocardial disease characterized by left ventricular hypertrophy in the absence of other etiologies. Clinical presentation may vary from asymptomatic to sudden cardiac death. Medical treatment is the first-line therapy for symptomatic patients. Extended left ventricular septal myectomy is the procedure of choice if medical treatment is unsuccessful or intolerable. More than 3,000 patients have had septal myectomy for HCM at the Mayo Clinic (MN, USA) from 1993 to 2016. Risk of hospital death after isolated septal myectomy for obstructive HCM is <1% and is similar to the risk of operation for elective mitral valve repair. Complications, such as complete heart block requiring permanent pacemaker, are uncommon (2%), although partial or complete left bundle branch block is a frequent finding on the postoperative ECG. Relief of left ventricular outflow tract (LVOT) obstruction with septal myectomy dramatically improves symptoms and exercise capacity in symptomatic patients with obstructive HCM. More than 90% of severely symptomatic patients have improvement by at least two functional classes, and reduction of outflow gradients by myectomy decreases or eliminates symptoms of dyspnea, angina and/or syncope. Basal obstruction with systolic anterior motion (SAM) is treated by transaortic myectomy. The transapical approach was applied in 115 patients with obstructive midventricular and apical variants of HCM between 1993 and 2012. All patients with midventricular obstruction had gradient relief and none developed an apical aneurysm or ventricular septal defect. Recurrent obstruction after satisfactory myectomy was rare. Septal myectomy effectively and definitively relieves LVOT obstruction and cardiac symptoms in patients with obstructive HCM. In experienced centers, early mortality for isolated septal myectomy is less than 1%, and overall results are excellent and continue to improve in the current era.

Outcome of Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy in Children and Young Adults

Obstructive hypertrophic cardiomyopathy (HCM) is an important cause of heart failure in children, but there are limited data addressing outcome of myectomy in children. Our objective was to evaluate the early and late results of septal myectomy in pediatric HCM. We reviewed 127 consecutive patients (62% male) who underwent transaortic septal myectomy for obstructive HCM from January 1975 to December 2010 at 21 or less years of age. Mean age at operation was 12.9 ± 5.5 years. Preoperatively, mean maximum instantaneous gradient was 89 mm Hg and 95% had significant systolic anterior motion (SAM) with mitral regurgitation (MR). Implantable cardioverter defibrillator (ICD) and permanent pacemaker prior to surgery was present in 21 patients (17%) and 15 (11.7%), respectively. Transaortic extended left ventricular septal myectomy was performed in all patients with no early deaths. Iatrogenic morbidity included new aortic valve regurgitation requiring repair in 7 (5.5%), mitral regurgitation needing repair in 2 (1.5%), ventricular septal defect in 1 (1%), and heart block requiring permanent pacemaker in 1 (1%). An ICD was implanted postoperatively in 8 during the same hospital admission. Mean MIG decreased from 89 to 6 mm Hg (p < 0.0001). Postoperatively, residual chordal SAM was present in 23% with mild or no MR; moderate MR was detected in 1 patient. Four patients (3%) died late during the mean follow-up period of 8.3 years (maximum, 37 years); 1 death was sudden. Overall survival was 98.6%, 94.9%, 92.4%, and 92.4% at 5, 10, 15, and 20 years, respectively. Freedom from any cardiac reoperation was 91.2%, 87.8%, 78.7%, and 72.7% at 5, 10, 15, and 20 years, respectively. Repeat septal myectomy was performed in 6 patients (5%). At late follow-up, 95% were in New York Heart Association functional class I or II and 25 patients underwent late ICD placement. Septal myectomy is safe and effective in children with obstructive HCM, but limited exposure may increase risk of aortic or mitral valve injury. Late survival is better than the previously published untreated natural history of HCM. Patient selection and surgical expertise remain critical components of septal myectomy, especially before considering a prophylactic myectomy in a seemingly asymptomatic patient.

Risk stratification for sudden cardiac death after septal myectomy

The importance of risk stratification for sudden cardiac death (SCD) after septal myectomy for hypertrophic obstructive cardiomyopathy (HOCM) has not been emphasized previously. We report 2 patients with SCD or ventricular tachycardia (VT) after septal myectomy for HOCM in whom risk factors for SCD were identified following surgical myectomy. One received an implantable cardioverter-defibrillator (ICD), which subsequently provided appropriate discharges for VT. The other delayed ICD implantation and suffered SCD. These cases emphasize the importance of risk stratification for SCD after septal myectomy for HOCM.

Impact of Septal Myectomy on Left Atrial Volume and Left Ventricular Diastolic Filling Patterns: An Echocardiographic Study of Young Patients with Obstructive Hypertrophic Cardiomyopathy

Septal myectomy in young patients with obstructive hypertrophic cardiomyopathy (HCM) can be performed with low mortality, and leads to excellent improvement in symptoms. Left atrial (LA) enlargement has been associated with exercise intolerance, severity of mitral regurgitation (MR), and left ventricular (LV) outflow tract (LVOT) obstruction in adults with HCM. Young patients (1-22 years of age) who had a septal myectomy for obstructive HCM between 2002 and 2005 were identified. Retrospective analyses of premyectomy and postmyectomy echocardiograms were performed. In this cohort of 32 patients (25 male), the average maximal LV wall thickness was 25 +/- 9 mm and LVOT maximal instantaneous gradient was 106 +/- 44 mm Hg. MR was present in all patients with a mean grade of 3 +/- 1. All patients had successful myectomy and there were no early deaths. After myectomy, LVOT maximal instantaneous gradient decreased to 17 +/- 13 mm Hg (P < .0001). Mean LA volume (LAV) index decreased from 52.1 +/- 2.2 to 33.2 +/- 11.9 mL/m(2) (P < .0001). Mean MR grade decreased to 2 +/- 1. Early mitral medial annular tissue Doppler velocity (E') increased from 6.2 +/- 1.9 to 13 +/- 2.6 cm/s (P < .043). A postmyectomy decrease in LAV index correlated with decrease in LVOT obstruction (P = .001) and change in degree of MR (P = .04). Septal myectomy not only reduces LVOT maximal instantaneous gradient and MR in young patients, but also results in decreased LAV index, and E/A and E/E' ratios. These hemodynamic improvements may contribute to the observed survival benefit and increased exercise tolerance observed after myectomy. This is the first series to demonstrate that LAV correlates closely with hemodynamic status in children with obstructive HCM and may be a significant predictor of clinical outcome in these patients.

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.

Septal Myectomy Results in Regression of Left Ventricular Hypertrophy in Patients With Hypertrophic Obstructive Cardiomyopathy

Background Hypertrophic cardiomyopathy (HCM) is a genetic disorder characterized by ventricular hypertrophy that occurs in the absence of predisposing cardiovascular stimuli; approximately one quarter of patients with HCM will have left ventricular (LV) outflow tract obstruction. Transaortic septal myectomy relieves outflow gradients and improves symptoms, but the effect of operation on ventricular hypertrophy is not well defined. Methods We reviewed 60 patients who underwent septal myectomy for obstructive HCM; all had complete two-dimensional and Doppler studies including calculation of LV mass and LV mass index before operation and after dismissal. Results Before myectomy the mean LV outflow gradient was 67 ± 44 mm Hg, and at dismissal the mean LV outflow gradient was 12 ± 13 mm Hg ( p < 0.004). We found a significant decrease in the LV mass and LV mass index that occurred early after operation and persisted beyond 2 years follow-up. The early decrease in LV mass was greatest in patients younger than 50 years, but patients of all ages benefited from extended septal myectomy with decrease in LV hypertrophy. Conclusions Transaortic septal myectomy results in significant decreases in LV mass and LV mass index. This favorable remodeling occurs early after operation and persists beyond 2 years. Whether the regression of LV mass continues to decrease or stabilize over time is unclear.