Abstract
Background
Novel treatments are needed for patients with severely symptomatic obstructive hypertrophic cardiomyopathy (oHCM). Radiofrequency (RF) septal ablation has emerged as a promising technique for improving the left ventricular outflow tract (LVOT) gradient and alleviating symptoms, potentially achieving outcomes comparable to the gold-standard surgical myectomy.
Objectives
To compare the 1-year efficacy and safety of surgical myectomy with RF septal ablation in patients with oHCM.
Methods
This observational, retrospective cohort study included patients aged≥18 years with oHCM and an LVOT gradient≥50 mm Hg, unresponsive to medical therapy, who underwent surgical myectomy or RF septal ablation between 2012 and 2022.
Results
The mean age was 49.8±14 and 56.9±10.9 years for the myectomy and RF groups, respectively, with the same sex distribution. The proportions of patients in functional class III distributions were 54.5% and 76.1% in the myectomy and RF groups, respectively. The LVOT gradient was 108.6±49.8 and 101.1±40.3 mm Hg for the myectomy and RF groups, respectively. Procedural success, defined as a reduction in the LVOT gradient to <50 mm Hg or an improvement to functional class I or II, showed no significant difference between the groups (HR: −3.5; 95% CI: −20.2 to 13.12; p=0.673). Complications occurred in 57.6% and 4.6% of the patients in the myectomy and RF groups, respectively (p<0.001).
Conclusions
RF septal ablation and surgical myectomy demonstrated similar efficacy in reducing LVOT gradients and improving symptoms. However, RF ablation exhibited a superior safety profile.
Keywords: Cardiomyopathy, Hypertrophic; Cardiac Surgical Procedures; Ablation Techniques
WHAT IS ALREADY KNOWN ON THIS TOPIC
Surgical myectomy has long been considered the gold standard treatment for severe symptomatic obstructive hypertrophic cardiomyopathy (oHCM).
Radiofrequency (RF) septal ablation is a less invasive alternative with the potential to achieve similar reductions in left ventricular outflow tract (LVOT) gradients and symptom improvement.
WHAT THIS STUDY ADDS
Our single-centre, retrospective cohort study demonstrated that at the 1-year follow-up, RF septal ablation was as effective as surgical myectomy in reducing LVOT gradients and improving symptoms.
HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY
RF septal ablation is a promising alternative treatment for patients with oHCM who are unresponsive to medical therapy.
Further multicentre clinical studies and randomised trials are warranted to validate the long-term efficacy and safety of RF septal ablation compared with surgical myectomy.
Introduction
Hypertrophic cardiomyopathy (HCM) is a genetically determined disease characterised by increased left ventricular mass.1 Approximately 70% of patients with HCM exhibit left ventricular outflow tract (LVOT) obstruction, which is associated with symptoms such as dyspnoea, chest pain and syncope. For patients with obstructive HCM (oHCM) and an LVOT gradient≥50 mm Hg who remain symptomatic despite optimal medical therapy, invasive interventions such as surgical myectomy and alcohol septal ablation (ASA) are considered.2
Myectomy, first described by Morrow and Brockenbrough in 1961, remains the gold-standard surgical treatment for oHCM. This procedure involves transaortic resection of the hypertrophied basal interventricular septum under cardiopulmonary bypass. Experienced centres demonstrate <1% mortality and clinical success rates exceeding 90%.3 However, myectomy may pose increased risks for patients with comorbidities or in centres with limited surgical expertise (<10 surgeries annually). Consequently, less invasive alternatives such as ASA have emerged.4
ASA offers lower perioperative morbidity and requires less resource-intensive postoperative care. However, its applicability is limited by anatomical constraints, as up to 20% of patients are unsuitable candidates owing to unfavourable coronary anatomy and unpredictable extent of myocardial damage.5
To address these limitations, radiofrequency (RF) septal ablation has emerged as a minimally invasive, alternative, independent of coronary anatomy. Analogous to electrophysiological techniques, RF energy is applied to the endocardial surface of the interventricular septum via a retrograde aortic or anterograde atrial septal approach under echocardiographic guidance.6
This study aimed to compare the safety and efficacy of RF septal ablation with those of myectomy in patients with oHCM over 1 year.
Methods
Study overview, objectives and population
This observational, retrospective cohort study based on medical records included patients aged≥18 years with oHCM and LVOT≥50 mm Hg with refractory symptoms despite optimal medical therapy. Patients underwent surgical myectomy or RF septal ablation between 2012 and 2022, with a minimum follow-up of 1 year. We hypothesised that catheter-based septal ablation using electrophysiology and transoesophageal echocardiography would achieve similar outcomes to surgical myectomy. The primary objective was to compare 1-year efficacy, whereas the secondary objective was to assess 1-year safety.
Inclusion and exclusion criteria
Patients with HCM and LVOT obstruction who underwent myectomy or septal ablation were included. Exclusion criteria included patients who underwent combined procedures (such as valve repair/replacement or coronary bypass), prior cardiac surgery, ejection fraction <50% and limited acoustic window.
Description of the RF ablation technique
RF ablation was primarily performed via an aortic retrograde approach under general anaesthesia. Ultrasound guidance was used to perform two femoral venous punctures and one femoral arterial access using 7F introducers. Under transoesophageal echocardiography guidance, the septal aspect of the left ventricle was mapped with the catheter, and multiple RF energy deliveries were administered in the vicinity of the aliasing region. The ablation power was titrated between 60 and 80 watts, with a target temperature of 60°C, and each RF application was maintained for 90–120 s in areas located at least 1 cm away from the His bundle recordings. In instances where the His bundle recordings were in close proximity to the target area, ablation was performed in the nearest safe region. Furthermore, when the target area exhibited hypokinesis along with significant oedema gradients, the ablation was reassessed and subsequently terminated. Consequently, no conduction lesions requiring pacemaker implantation were observed.
Study endpoints
The primary efficacy endpoint was LVOT gradient reduction to <50 mm Hg or an improvement in New York Heart Association (NYHA) functional class (I or II). Secondary endpoints included stroke, acute myocardial infarction, all-cause mortality, renal failure requiring dialysis, transfusion, pacemaker implantation and infection.
Statistical analysis
Descriptive analysis results were presented using graphs and tables. Fisher’s exact test and the Shapiro-Wilk normality test were applied for categorical and numerical variables. Normally distributed variables were analysed using paired t-tests, whereas non-normally distributed variables were analysed using Wilcoxon tests. A significance level of α=5% was considered for all inferential analyses (R Software, Vienna, Austria).
Results
Study population
This study enrolled 81 patients who underwent myectomy (n=33) or RF septal ablation (n=48) between 2012 and 2022. Two patients in the RF septal ablation group were excluded because of a concomitant diagnosis of aortic stenosis requiring invasive valve intervention. Ultimately, 46 patients underwent RF septal ablation.
Table 1 presents the baseline characteristics of the study population. The cohort was predominantly women (70.9%), with a mean age of 49.8 and 56.9 years in the myectomy and RF septal ablation groups, respectively (p=0.018). The myectomy group had a higher proportion of patients in NYHA functional class IV than the RF ablation group (15 of 33 (45.5%) vs 10 of 46 (22.2%); p=0.048). Additionally, the myectomy group had more current or former smokers (14 of 33 (64.6%) vs 15 of 46 (32.6%); p=0.032) and more individuals using amiodarone (11 of 33 (33.3%) vs 10 of 46 (21.7%); p=0.001) than the RF ablation group.
Table 1. Baseline clinical characteristics of patients undergoing myectomy and RF septal ablation.
| Myectomy (n=33) | RF septal ablation (n=46) | P value | |
| Age, years | 49.8±14 | 56.9±10.9 | 0.018 |
| Sex | 0.616 | ||
| Men | 11 (33.3%) | 12 (58.2%) | |
| Women | 22 (66.7%) | 34 (73.9%) | |
| Race | 0.578 | ||
| White | 26 (78.8%) | 31 (67.4%) | |
| Black | 3 (9.1%) | 7 (15.2%) | |
| Mixed race | 4 (12.1%) | 8 (17.4%) | |
| NYHA functional class | 0.048 | ||
| III | 18 (54.5%) | 35 (76.1%) | |
| IV | 15 (45.5%) | 10 (23.9%) | |
| Family history of HCM | 0.05 | ||
| Yes | 5 (15.2%) | 10 (21.7%) | |
| No | 28 (84.8%) | 30 (65.2%) | |
| Ignore | 0 (0%) | 6 (13%) | |
| Medical history | |||
| Hypertension | 21 (63.6%) | 30 (65.2%) | 1 |
| Dyslipidaemia | 19 (57.6%) | 21 (45.7%) | 0.364 |
| Type 2 diabetes | 8 (24.2%) | 11 (23.9%) | 1 |
| Coronary artery disease | 4 (12.1%) | 7 (15.2%) | 0.754 |
| Obesity | 12 (36.4%) | 20 (43.5%) | 0.643 |
| Asthma | 2 (6.1%) | 2 (4.4%) | 1 |
| Smoking/former smoking | 14 (64.6%) | 15 (32.6%) | 0.032 |
| Background HCM therapy | |||
| Beta-blocker | 31 (93.9%) | 45 (97.8%) | 0.568 |
| Calcium channel blocker | 7 (21.2%) | 10 (21.7%) | 1 |
| Amiodarone | 11 (33.3%) | 2 (4.3%) | 0.001 |
| Furosemide | 8 (24.2%) | 9 (19.6%) | 0.782 |
| Disopyramide | 1 (3%) | 3 (6.5%) | 0.636 |
| ICD | 6 (18.2%) | 7 (15.2%) | 0.765 |
| ECG cardiac rhythm | 0.549 | ||
| Atrial fibrillation | 4 (12.1%) | 2 (4.4%) | |
| Sinus rhythm | 28 (84.8%) | 41 (91.1%) | |
| Pacemaker | 1 (3%) | 2 (4.4%) | |
| Heart rate, beats per minute | 64.6±9.1 | 64.4±7.7 | 0.940 |
| Systolic blood pressure, mm Hg | 126.8±20.4 | 126.3±19.6 | 1 |
| Body mass index, kg/m2 | 29.4±5.8 | 30.5±5.9 | 0.414 |
| Serum NT-proBNP, pg/mL | 1.941±1.528 | 1.980±1.942 | 0.784 |
| Serum creatinine, mg/dL | 0.9±0.3 | 1.0±0.2 | 0.238 |
NT-proBNP: N-terminal pro–B-type natriuretic peptide
HCM, hypertrophic cardiomyopathy; ICD, implantable cardioverter-defibrillator; NYHA, New York Heart Association; RF, radiofrequency
Table 2 presents echocardiographic data of the myectomy and RF septal ablation groups. None of the groups showed differences in any of the evaluated parameters (paired samples).
Table 2. Baseline echocardiographic characteristics of patients undergoing myectomy and RF septal ablation.
| Myectomy (n=33) | RF septal ablation (n=46) | P value | |
| LVEF (%) | 67.7±4.9 | 66.4±3.2 | 0.180 |
| LVOT (mm Hg) | 108.6±49.8 | 101.1±40.3 | 0.796 |
| Septum (mm) | 19.7±4.6 | 18.3±3.1 | 0.267 |
| Diastolic dysfunction | 0.083 | ||
| Grade I | 17 (51.5%) | 18 (39.2%) | |
| Grade II | 9 (27.3%) | 19 (41.3%) | |
| Grade III | 0 (0%) | 0 (0%) | |
| Indeterminate | 0 (0%) | 9 (19.5%) | |
| Not evaluated | 7 (21.2%) | 0 (0%) | |
| PASP (mm Hg) | 47.9±8.2 | 46.1±9 | 0.419 |
| SAM | 28 (84.8%) | 34 (77.3%) | 0.563 |
| Left atrial (mm) | 46.9±6.3 | 47.1±6.9 | 0.916 |
| Left atrial volume index (mL/m2) | 53.3±12.1 | 56.2±17.4 | 0.940 |
| Mitral regurgitation | 0.149 | ||
| Absent | 0 (0%) | 2 (4.4%) | |
| Mild | 12 (36.4%) | 25 (55.6%) | |
| Moderate | 15 (45.5%) | 14 (31.1%) | |
| Severe | 6 (18.2%) | 4 (8.9%) | |
| Aortic regurgitation | 0.820 | ||
| Absent | 20 (60.6%) | 27 (58.7%) | |
| Mild | 13 (39.4%) | 19 (41.3%) | |
| Moderate | 0 (0%) | 0 (0%) | |
| Severe | 0 (0%) | 0 (0%) | |
| LVEDD (mm) | 45.6±6.2 | 46±4.9 | 0.747 |
LVEDD, left ventricular end-diastolic diameterLVEFleft ventricular ejection fractionLVOT, left ventricular outflow tract; PASP, pulmonary artery systolic pressure; RF, radiofrequency; SAM, systolic anterior motion of the mitral valve
Study endpoints
Primary outcome
Efficacy
Procedural success, defined as the reduction of LVOT gradient to <50 mm Hg or an improvement in NYHA functional class to I or II, did not significantly differ between individuals who underwent myectomy and those who underwent RF septal ablation (HR: −3.5; 95% CI: −20.2 to 13.12; p=0.673).
Compared with 85.4% of the group that underwent RF septal ablation, 88.9% of individuals who underwent myectomy achieved an LVOT gradient reduction to <50 mm Hg or an improvement in NYHA functional class to I or II after 1 year (figure 1).
Figure 1. Efficacy and safety of myectomy and radiofrequency (RF) septal ablation for the treatment of hypertrophic obstructive cardiomyopathy. *Efficacy: defined as a reduction in the left ventricular outflow tract to less than 50 mm Hg or an improvement in New York Heart Association functional class to class I or II. **Safety: included the evaluation of the occurrence of symptoms indicative of stroke, acute myocardial infarction, all-cause mortality, acute renal failure requiring dialysis, the need for blood transfusion, the need for pacemaker implantation and skin or bloodstream infections.
Reduction of LVOT gradient
The LVOT gradient decreased from 108.6 mm Hg (± 49.8) to 24.6 mm Hg (± 46.8) in the myectomy group (mean difference of −85.6) and from 101.1 mm Hg (± 40.3) to 43.3 mm Hg (±35.7) in the RF ablation group (mean difference of −58.8; p=0.064). Figures2 3 illustrate the changes in these variables.
Figure 2. Profile plot of left ventricular outflow tract (LVOT) gradient reduction 1 year after myectomy (blue line) and radiofrequency (RF) septal ablation (red line).
Figure 3. Box plot of the difference between postprocedure and preprocedure left ventricular outflow tract (LVOT) gradient in patients undergoing myectomy (left) and radiofrequency (RF) septal ablation (right).
When one component of the primary outcome was analysed separately, the reduction in LVOT gradient to <50 mm Hg was similar in both groups. Compared with 26 of 41 patients (63.4%) in the RF ablation group, 22 of 27 patients (81.5%) in the myectomy group achieved LVOT gradient values below 50 mmHg. The absolute difference between the groups was −18.1% (95% CI: −39.6% to 3.46%), with a p value of 0.098 (figure 4). These results suggest that myectomy and RF septal ablation have similar efficacies in reducing LVOT gradient to <50 mm Hg.
Figure 4. left ventricular outflow tract gradient (LOVTG)<50 mm Hg 1 year after myectomy (left) and radiofrequency (RF) septal ablation (right).
Reduction of dyspnoea by NYHA functional class
Baseline NYHA functional classes in the myectomy group were III (54.55%) and IV (45.45%), progressing after 1 year to NYHA class III in 15.15%, II in 30.3% and I in 39.39% of patients. In contrast, the RF ablation group had baseline NYHA functional classes of III (76.09%) and IV (23.91%), regressing after 1 year to NYHA class IV in 2.17%, III in 17.39%, II in 32.61% and I in 41.3% of patients (figure 5).
Figure 5. New York Heart Association (NYHA) functional class progression in patients undergoing myectomy (left) and radiofrequency (RF) septal ablation (right).
When one component of the primary outcome was analysed separately, the improvement in the NYHA functional class to I or II was similar in both groups. Compared with 34 of 43 patients (79.1%) in the RF ablation group, 23 of the 28 patients (82.1%) in the myectomy group achieved NYHA class I or II. The absolute difference between the groups was −3.1% (95% CI: −22.4% to 16.29%), with a p value of 0.752 (figure 6). These results suggest a similar efficacy between myectomy and RF septal ablation in improving NYHA functional class.
Figure 6. New York Heart Association (NYHA) functional class I or II dyspnoea 1 year after myectomy. RF, radiofrequency.
Secondary outcome
Safety
The secondary outcome of the study was a safety assessment of both procedures by evaluating the incidence of the following adverse events:
Stroke.
Acute myocardial infarction.
All-cause mortality.
Acute renal failure requiring haemodialysis.
Ventricular septal defect.
Need for blood transfusion.
Need for pacemaker implantation.
Skin or bloodstream infection.
When analysed collectively, complications occurred in 19 (57.6%) patients in the myectomy group, compared with 3 (6.5%) in the RF septal ablation group (p<0.001), indicating a superior safety profile for RF septal ablation. This difference was influenced by the occurrence of ventricular septal defects in 5 (15.2%) patients, the need for pacemaker implantation in 8 (24.2%) patients, acute renal failure requiring haemodialysis in 5 (15.2%) patients, blood transfusion in 12 (36.4%) patients and bloodstream infections in 6 (18.2%) patients in the myectomy group. In contrast, none of the patients in the RF septal ablation group developed these complications. Table 3 summarises the complications observed in both groups.
Table 3. Postprocedural complications.
| Variable | Myectomy (n=33) | RF septal ablation (n=46) | P value |
| Ventricular septal defect | 5 (15.2%) | 0 (0%) | 0.012 |
| Pacemaker | 8 (24.2%) | 0 (0%) | <0001 |
| All-cause mortality | 5 (15.2%) | 1 (2.3%) | 0.078 |
| Acute myocardial infarction | 0 (0%) | 1 (2.3%) | 0.75 |
| Stroke | 2 (6.1%) | 0 (0%) | 0.18 |
| Haemodialysis | 5 (15.2%) | 0 (0%) | 0.012 |
| Blood transfusion | 12 (36.4%) | 0 (0%) | <0001 |
| Skin infection | 3 (9.1%) | 0 (0%) | 0.075 |
| Bloodstream infection | 6 (18.2%) | 0 (0%) | 0.005 |
| Any complication | 19 (57.6%) | 2 (4.6%) | <0001 |
RF, radiofrequency
In the RF ablation group, one case of acute myocardial infarction (2.3%) and one death (2.3%) were observed. In contrast, the myectomy group had five deaths (15.2%) (p=0.078) and no cases of acute myocardial infarction (p=0.75), though these differences were insignificant.
Discussion
This study evaluated the efficacy of both procedures using the criteria from the VALOR-HCM study (Assessment of the Efficacy and Safety of Mavacamten in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy Who Are Eligible for Septal Reduction Therapy), such as reducing the LVOT gradient to <50 mm Hg or improving dyspnoea to NYHA class I or II.7 It was conducted at the Instituto Dante Pazzanese de Cardiologia, compared surgical myectomy and RF ablation in patients with oHCM. Treatment selection was based on procedural availability, ensuring unbiased assessment. All patients had preserved ventricular function, significant LVOT gradients (>100 mm Hg), pulmonary hypertension and left atrial enlargement. Diastolic function data were missing for 21.2% of patients undergoing myectomy because of outdated echocardiographic protocols before the 2016 guideline update.
Patients undergoing RF ablation were older (56.9±10.9 years) than those undergoing myectomy (49.8±14 years, p=0.018), reflecting the increased surgical risks in older populations. A higher proportion of patients who underwent myectomy were NYHA class IV; however, this likely did not influence treatment selection, as all patients were symptomatic (NYHA III or IV).
After 1 year, 88.9% and 85.4% of the patients in the myectomy and RF ablation achieved these outcomes, respectively, with no significant differences between the groups. These results align with the reported myectomy success rates of 90–95%, which were slightly lower in this study, likely because of differences in surgical volumes.3 8 9 LVOT gradient reductions were comparable between the groups. Myectomy reduced gradients from 108.6±49.8 to 24.6±46.8 mm Hg, with 63.4% achieving gradients <50 mm Hg. RF ablation reduced gradients from 101.1±40.3 to 43.3±35.7 mmHg, consistent with earlier studies from the same centre.6 Previous meta-analyses have reported gradient reductions of up to 97.6 mm Hg, supporting the effectiveness of RF ablation.10
Symptomatic relief was also similar between the groups. In this study, 82.1% and 79.1% of patients in the myectomy and RF ablation group achieved NYHA class I or II, respectively, with no significant difference (p=0.752). These findings are consistent with those of previous studies reporting >90% NYHA class improvement after myectomy.9 11 Studies have reported that the proportion of patients with NYHA functional class III/IV decreased from 51% to none.12
Safety outcomes are critical when comparing therapies. The mortality rate for the myectomy group was 15.2% (five cases), which was significantly higher than the <1% reported in high-volume centres.13 This discrepancy may be attributed to the small sample size, case complexity and patient selection at this tertiary care centre. Conversely, RF ablation had a mortality rate of 2.3%, comparable to the 2.2% reported in the literature.14 The complication rate for myectomy exceeded expectations for specialised centres, likely reflecting disease severity and procedural challenges in this cohort.
A Brazilian study of 12 patients undergoing RF septal ablation reported significant LVOT gradient reductions (96.8±34.7–36.1±23.8 mm Hg, p=0.0001) after 1 year, with no major complications.6 A US study demonstrated that 10 of 11 patients achieved an 85% reduction in resting and provoked LVOT gradients, with marked NYHA functional class improvement.15 These findings support RF ablation as a potential alternative to myectomy, warranting direct comparisons of their safety and efficacy.
This observational study has inherent limitations. Its design and small sample size limit the ability to perform robust multivariate analyses and increase the risk for residual confounding. Additionally, the study cohort consisted predominantly of Caucasian patients treated in high-volume HCM centres, limiting generalisability to other populations or lower-volume centres. Future randomised prospective trials are required to confirm the equivalence of these methods.
In patients with highly symptomatic oHCM meeting guideline criteria for septal reduction therapy, RF ablation was as effective as gold-standard myectomy in reducing the LVOT gradient and improving NYHA functional class to I or II, with RF ablation being the safer option.
Competency in patient care and procedural skills
In patients with symptomatic oHCM, myectomy was as effective as RF ablation in reducing the LVOT gradient and improving NYHA functional class to I or II.
Acknowledgements
We would like to express our gratitude to the Department of Cardiomyopathies at the Dante Pazzanese Institute of Cardiology for their exceptional medical services and valuable contributions to the research. We also thank the hospital administration and medical teams for their collaborative work in supporting patients, conducting examinations and analysing clinical cases. Special thanks go to the patients for their trust, which enabled the continuous improvement of care. Finally, we thank our families for their unwavering support and understanding throughout this journey; their encouragement was essential for completing this work.
Footnotes
Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Data availability free text: No data are available.
Patient consent for publication: Not applicable.
Ethics approval: Collected data were used solely for this study, and patient anonymity was preserved. This study involves human participants and was approved by ethics committee of the Instituto Dante Pazzanese de Cardiologia (CAAE: 57364322.3.0000.5462, opinion number: 5.395.718) on 9 May 2022. Project presentation: In the CEP Protocol: 5246. Participants gave informed consent to participate in the study before taking part.
Provenance and peer review: Part of a topic collection; Not commissioned; externally peer-reviewed.
Author note: Diversity information: This study was conducted in Brazil, a developing nation, at a public hospital that relies on government funding. The lead author, a young woman, underscores the significance of diversity in scientific leadership. Furthermore, the author team was deliberately composed of equally representative men and women, demonstrating our commitment to promote gender equality and inclusivity in the pursuit of clinically impactful research.
Data availability statement
Data may be obtained from a third party and are not publicly available.
References
- 1.Authors/Task Force members. Elliott PM, Anastasakis A, et al. 2014 ESC Guidelines on diagnosis and management of hypertrophic cardiomyopathy: the Task Force for the Diagnosis and Management of Hypertrophic Cardiomyopathy of the European Society of Cardiology (ESC) Eur Heart J. 2014;35:2733–79. doi: 10.1093/eurheartj/ehu284. [DOI] [PubMed] [Google Scholar]
- 2.Leggit JC, Whitaker D. Diagnosis and Management of Hypertrophic Cardiomyopathy: Updated Guidelines From the ACC/AHA. Am Fam Physician. 2022;105:207–9. [PubMed] [Google Scholar]
- 3.Maron BJ, Dearani JA, Ommen SR, et al. Abstract 13977: Low Operative Mortality Achieved With Surgical Septal Myectomy: Role of Dedicated Hypertrophic Cardiomyopathy Centers in the Management of Dynamic Subaortic Obstruction. Circulation . 2015;132:1307–8. doi: 10.1161/circ.132.suppl_3.13977. [DOI] [PubMed] [Google Scholar]
- 4.Morrow AG, Reitz BA, Epstein SE, et al. Operative treatment in hypertrophic subaortic stenosis. Techniques, and the results of pre and postoperative assessments in 83 patients. Circulation. 1975;52:88–102. doi: 10.1161/01.cir.52.1.88. [DOI] [PubMed] [Google Scholar]
- 5.Sherrid MV, Massera D, Swistel DG. Surgical Septal Myectomy and Alcohol Ablation: Not Equivalent in Efficacy or Survival. J Am Coll Cardiol. 2022;79:1656–9. doi: 10.1016/j.jacc.2022.03.332. [DOI] [PubMed] [Google Scholar]
- 6.Valdigem BP, Correia EB, Moreira DAR, et al. Ablação Septal Com Cateteres e Radiofrequência Guiada Pela Ecocardiografia Para Tratamento de Pacientes Com Cardiomiopatia Hipertrófica Obstrutiva: Experiência Inicial. Septal Ablation with Radiofrequency Catheters Guided by Echocardiography for Treatment of Patients with Obstructive Hypertrophic Cardiomyopathy: Initial Experience. Arq Bras Cardiol. 2022;118:861–72. doi: 10.36660/abc.20200732. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Desai MY, Owens A, Geske JB, et al. Myosin Inhibition in Patients With Obstructive Hypertrophic Cardiomyopathy Referred for Septal Reduction Therapy. J Am Coll Cardiol. 2022;80:95–108. doi: 10.1016/j.jacc.2022.04.048. [DOI] [PubMed] [Google Scholar]
- 8.Hodges K, Rivas CG, Aguilera J, et al. Surgical management of left ventricular outflow tract obstruction in a specialized hypertrophic obstructive cardiomyopathy center. J Thorac Cardiovasc Surg. 2019;157:2289–99. doi: 10.1016/j.jtcvs.2018.11.148. [DOI] [PubMed] [Google Scholar]
- 9.Rastegar H, Boll G, Rowin EJ, et al. Results of surgical septal myectomy for obstructive hypertrophic cardiomyopathy: the Tufts experience. Ann Cardiothorac Surg. 2017;6:353–63. doi: 10.21037/acs.2017.07.07. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Shelke AB, Menon R, Kapadiya A, et al. A novel approach in the use of radiofrequency catheter ablation of septal hypertrophy in hypertrophic obstructive cardiomyopathy. Indian Heart J. 2016;68:618–23. doi: 10.1016/j.ihj.2016.02.007. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Ommen SR, Ho CY, Asif IM, et al. 2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines. Circulation. 2024;149:e1239–311. doi: 10.1161/CIR.0000000000001250. [DOI] [PubMed] [Google Scholar]
- 12.Xie X, Chen S, Cui Y, et al. Midterm Outcomes of Percutaneous Intramyocardial Septal Radiofrequency Ablation for Hypertrophic Cardiomyopathy: A Single-Center, Observational Study. J Am Heart Assoc. 2024;13:e034080. doi: 10.1161/JAHA.123.034080. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Geske JB, Ommen SR, Gersh BJ. Hypertrophic Cardiomyopathy: Clinical Update. JACC Heart Fail. 2018;6:364–75. doi: 10.1016/j.jchf.2018.02.010. [DOI] [PubMed] [Google Scholar]
- 14.Yang H, Yang Y, Xue Y, et al. Efficacy and safety of radiofrequency ablation for hypertrophic obstructive cardiomyopathy: A systematic review and meta-analysis. Clin Cardiol . 2020;43:450–8. doi: 10.1002/clc.23341. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Crossen K, Jones M, Erikson C. Radiofrequency septal reduction in symptomatic hypertrophic obstructive cardiomyopathy. Heart Rhythm. 2016;13:1885–90. doi: 10.1016/j.hrthm.2016.04.018. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
Data may be obtained from a third party and are not publicly available.