Alcohol Septal Ablation for Obstructive Hypertrophic Cardiomyopathy: A Word of Endorsement

Morphological anomalies in obstructive hypertrophic cardiomyopathy: Insights from four-dimensional computed tomography and surgical correlation

Hypertrophic cardiomyopathy (HCM) is a genetic disorder in which left ventricular outflow tract obstruction critically affects symptoms and prognosis. Traditionally, left ventricular outflow tract obstruction was primarily attributed to septal hypertrophy with systolic anterior motion of the mitral valve. However, recent evidence highlights significant contributions from the mitral valve and papillary muscle anomalies, as well as an apical-basal muscle bundle observed in HCM patients. Accurate morphological assessment is essential when considering septal reduction therapy. While transesophageal echocardiography and cardiac magnetic resonance are recommended for assessing the anomalous structures, four-dimensional computed tomography offers superior spatial resolution and multiplanar reconstruction capabilities. These features enable the evaluation of details of the morphological anomalies, such as the apical-basal muscle band, papillary muscle anomalies, subaortic stenosis, and right ventricular outflow tract obstruction. Based on the detailed assessment of these morphological features, four-dimensional computed tomography has been utilized for planning of surgical correction in a comprehensive HCM center. This approach facilitates the intervention strategies and may improve outcomes in septal reduction therapy for obstructive HCM.

An overview of the treatments for hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a very prevalent inherited disease with a wide global distribution and a prevalence rate of approximately 0.2% in the general population. Left ventricular hypertrophy (LVH) caused by sarcomere mutation is the primary reason of HCM. The histopathology feature is that cardiomyocyte hypertrophy, myocyte disorder and myocardial fibrosis lead to diminished diastolic function, left ventricular outflow tract obstruction (LVOTO) and arrhythmia, all of which result in serious cardiac complications. Previously, HCM was considered a malignant disease that was almost untreatable. With the improvement of medical standards and increasing awareness of HCM, it has become a highly treatable disease in contemporary times, with a significant decrease in mortality rates. However, there are still significant unmet requirements in the therapy of HCM. This paper draws on more than 100 references from the past four decades and summarizes current advances in the treatment of HCM. The article will review the pathogenesis and types, recent development in pharmacotherapy, invasive treatments and gene therapies, as well as dilemma and future development of HCM.

Trans-Atlantic Differences in Approach to Sudden Death Prevention in Patients With Hypertrophic Cardiomyopathy

The American approach to predicting sudden cardiac death (SCD) in patients with hypertrophic cardiomyopathy diverges from the European method in that it relies on major risk factors independently justifying the implantation of an implantable cardioverter-defibrillator for primary prevention, whereas the European approach uses a mathematical equation to estimate a 5-year risk percentage. The aim of this review is to outline the differences between the American and European guidelines and to show how they have arisen. Furthermore, it will provide insight into the future of SCD risk prediction in patients with hypertrophic cardiomyopathy. The American SCD risk prediction method has high sensitivity but limited specificity, whereas the European method has the opposite. These differences in sensitivity and specificity likely contribute to the fact that primary prevention implantable cardioverter-defibrillator utilization is twofold higher in the United States. It is highly likely that new insights and new imaging modalities will enhance prediction models in the near future. Genotyping could potentially assume a significant role. Left ventricular global longitudinal strain was recently shown to be an independent predictor of SCD. Furthermore, after late gadolinium enhancement, additional cardiac magnetic resonance techniques such as T1 mapping and diffusion tensor imaging are showing encouraging outcomes in predicting SCD. Ultimately, it is conceivable that integrating diverse morphological and genetic characteristics through deep learning will yield novel insights and enhance SCD prediction methods.

Septal Microsphere Embolization in Hypertrophic Obstructive Cardiomyopathy

Alcohol septal ablation is an established treatment for selected patients with hypertrophic cardiomyopathy and left ventricular outflow tract obstruction (LVOT). The safety and efficacy of septal microsphere embolization (SME) have not been studied. We conducted a retrospective analysis of SME procedures performed at our center from 2006 to 2021 using 75-µm microspheres. The primary end point was LVOT gradient reduction. Secondary outcomes included periprocedural mortality, conduction disturbances, access site complications, and duration of hospitalization. The population comprised 76 patients (median age 61 years, men 43%). Dyspnea New York Heart Association ≥III was present in 65 patients (86%); ventricular tachycardia and previous syncope were described in 4% and 18%, respectively. Median duration of hospitalization was 13 days, and the time to first follow-up was 4 months. SME resulted in a significant reduction at rest (41 vs 12 mm Hg, mean Δ PG = -71%, p <0.001) and provoked LVOT gradients (94 vs 29 mm Hg, mean Δ PG = -75%, p <0.001). Periprocedural death occurred in 1 patient (1%) who underwent SME after transcatheter aortic valve replacement. Complete atrioventricular block was observed in 5 patients (7%). Left bundle branch block was diagnosed in 1 case (1%) and right bundle branch block in 3 (4%). Access site complications were observed in 4 patients (5%). In conclusion, SME is a safe and effective alternative to alcohol septal ablation. The potential advantages of microspheres are still to be investigated in prospective studies.

Hypertrophic Cardiomyopathy: Current Treatment and Future Options

Hypertrophic cardiomyopathy (HCM) is a disease involving the cardiac sarcomere. It is associated with various disease-causing gene mutations and phenotypic expressions, managed with different therapies with variable prognoses. The heterogeneity of the disease is evident in the fact that it burdens patients of all ages. HCM is the most prevalent cause of sudden death in athletes. However, several technological advancements and therapeutic options have reduced mortality in patients with HCM to 0.5% per year. In addition, rapid advances in our knowledge of the molecular defects accountable for HCM have strengthened our awareness of the disorder and recommended new approaches to the assessment of prognosis. Despite all these evolutions, a small subgroup of patients with HCM will experience sudden cardiac death, and risk stratification remains a critical challenge. This review provides a practical guide to the updated recommendations for patients with HCM, including clinical updates for diagnosis, family screening, clinical imaging, risk stratification, and management.

Single Center Experience of Percutaneous Septal Ablation in Patients With Hypertrophic Cardiomyopathy With A Novel Agent: Polidocanol

Septal reduction therapy is recommended in patients with obstructive hypertrophic cardiomyopathy (HCM) who remain symptomatic under maximally tolerated optimal medical treatment. Alcohol septal ablation is a favorable option, especially in patients with high surgical risk or who refuse surgery. Alcohol; causes scar-related ventricular arrhythmias and advanced heart blocks more frequently than surgical myectomy. Therefore, novel, safer agents are required for percutaneous septal ablation therapy. All the patients who underwent percutaneous septal ablation between January 2017 and June 2021 with polidocanol because of ongoing symptoms related to HCM despite maximally tolerated medical treatment were enrolled. Data were obtained retrospectively from the hospital electronic database. A total of 28 patients were included. Median age was 61 years (43.5-67), and 19 (67.8%) patients were male. Most of the patients underwent index procedures; however, only 2 cases had history of previous septal ablation. Median follow-up was 3.5 months (0.25 to 12.25). Median left ventricular outflow tract (LVOT) gradient at rest was 68.5 (37-80) mm Hg, and after Valsalva maneuver median LVOT gradient was 95.5 (75-125) mm Hg. Median volume of polidocanol used in procedures was 2 (2-3.37) ml, and mean procedure time was 28.1 ± 2.5 minutes. LVOT gradient invasively measured was significantly reduced (mean 76.5 mm Hg vs mean 30 mm Hg; p <0.001) immediately after the septal ablation. Conduction defects developed in 18 patients (64.2%); however, de novo permanent cardiac implantable electronic device implantation was required in only 4 (14.3%) cases. Leakage of polidocanol and mortality did not occur in any cases. Pericardial effusion developed in only 1 case, and it resolved with medical treatment. After mean 3.5 months follow-up, both LVOT gradient and New York Heart Association functional class parameters were better than baseline values. In conclusion, polidocanol is a safe and effective agent for septal ablation in patients with HCM. Outcomes and complication rates are similar with alcohol septal ablation.

Percutaneous Intramyocardial Septal Radiofrequency Ablation Relieving Residual Left Ventricular Outflow Tract Obstruction Following Alcohol Septal Ablation

PIMSRA offers a less invasive option to treat residual LVOTO after ASA.

Multimodality imaging is necessary to guide this procedure.

Myocardial contrast echocardiography can be used to confirm successful PIMSRA.

Treatment of Severe Left Ventricular Outflow Tract Obstruction and Mitral Regurgitation With Alcohol Septal Ablation

•

Hypertrophic cardiomyopathy is a common genetic heart disease.

•

Patients can have variable clinical manifestations and severity of disease.

•

Manifestations include LVOT obstruction and MR.

•

Alcohol septal ablation can successfully treat LVOT obstruction and MR.

The mechanics of the heart: zooming in on hypertrophic cardiomyopathy and cMyBP-C

Hypertrophic cardiomyopathy (HCM), a disease characterized by cardiac muscle hypertrophy and hypercontractility, is the most frequently inherited disorder of the heart. HCM is mainly caused by variants in genes encoding proteins of the sarcomere, the basic contractile unit of cardiomyocytes. The most frequently mutated among them is MYBPC3, which encodes cardiac myosin-binding protein C (cMyBP-C), a key regulator of sarcomere contraction. In this review, we summarize clinical and genetic aspects of HCM and provide updated information on the function of the healthy and HCM sarcomere, as well as on emerging therapeutic options targeting sarcomere mechanical activity. Building on what is known about cMyBP-C activity, we examine different pathogenicity drivers by which MYBPC3 variants can cause disease, focussing on protein haploinsufficiency as a common pathomechanism also in nontruncating variants. Finally, we discuss recent evidence correlating altered cMyBP-C mechanical properties with HCM development.

Case Report: Minimally Invasive Therapy by Transcatheter Aortic Valve Replacement and Percutaneous Intramyocardial Septal Radiofrequency Ablation for a Patient With Aortic Stenosis Combined With Hypertrophic Obstructive Cardiomyopathy: Two-Year Follow-Up Results

With the development of minimally invasive technologies in the medical field, more and more technologies can replace surgical thoracotomy and relieve the pain of disease via minimally invasive methods. We reported a case of aortic valve stenosis combined with left ventricular outflow track obstruction treated by two minimally invasive techniques, transcatheter aortic valve replacement and transthoracic echocardiography–guided percutaneous intramyocardial septal radiofrequency ablation, and followed up for 2 years.

Predicting complete heart block after alcohol septal ablation for hypertrophic cardiomyopathy using a risk stratification model and clinical tool

BACKGROUND

Alcohol septal ablation (ASA) is a proven method of septal reduction for patients with drug refractory, symptomatic hypertrophic obstructive cardiomyopathy (HOCM). This procedure is associated with a 6.5-11% risk of complete heart block (CHB).

OBJECTIVE

The aim of this study is to determine factors that predict CHB and to develop a clinical tool for risk stratification of patients.

METHODS

Patients were enrolled into an ongoing ASA study. A total of 636 patient procedures were included, 527 of whom were used in the development of the prediction tool, and 109 of whom were used for independent validation. Multivariate analysis was performed with odds ratios used to develop the clinical prediction tool. This was then internally and externally validated.

RESULTS

Of the 527 in the prediction cohort, 46 developed CHB. The predictors of CHB were age ≥50 years, pre-ASA left bundle branch block (LBBB), transient procedural high-grade block, post-ASA PR prolongation ≥68 ms, and new bifascicular block. An 11-point clinical prediction tool was developed to classify these factors. Internal validation using a receiver operating characteristic curve revealed an area under the curve of 0.88 for the clinical prediction tool. External validation using 109 contemporary patients revealed a 98% negative predictive value, 24% positive predictive value, 75% sensitivity, and 81% specificity in high-risk patients.

CONCLUSION

Among patients undergoing ASA, the risk of CHB can be predicted with easily obtained clinical and electrocardiographic factors. This clinical prediction tool allows identification of high-risk patients who may benefit from additional monitoring and therapy.

Targeting Alcohol Septal Ablation in Patients with Obstructive Hypertrophic Cardiomyopathy Candidates for Surgical Myectomy: Added Value of Three-Dimensional Intracoronary Myocardial Contrast Echocardiography

Background: Myocardial contrast two-dimensional echocardiography (MC-2DE) is widely used to address alcohol septal ablation (ASA) in obstructive hypertrophic cardiomyopathy (HCM). Owing to its limited cut-planes, MC-2DE may inaccurately identify the contrast misplacement associated with an unsuccessful or complicated ASA outcome. Objective: The aim of this study was to assess the added value of myocardial contrast three-dimensional echocardiography (MC-3DE) compared with MC-2DE to identify the appropriate matching between the target septal zone (TSZ) and coronary artery branch for safe and long-term effective ASA in HCM patients. Methods: A consecutive series of 52 symptomatic obstructive HCM patients referred for isolated surgical myectomy (SM) was analyzed with MC-2DE and MC-3DE following injection of echocontrast into one or more septal branches. MC-2DE and MC-3DE patterns were categorized according to complete (Type 1) or incomplete (Type 2) TSZ covering, high-risk (Type 3) exceeding TSZ, or life-threatening outside TSZ distribution (Type 4). Results: MC-2DE per patient analysis showed a Type 1 pattern in 32 patients and Types 2–4 in the remaining 20 patients; subsequent MC-3DE analysis provided a re-phenotyping of MC-2DE findings in 22 of the 52 patients (42%), showing a high-risk Type 2 pattern in 17 of the 32 patients with Type 1, and a new life-threatening Type 4 in three patients with Type 2, respectively. All patients with MC-3DE Type 1 pattern underwent safe and effective ASA with a long-term uneventful follow-up, while the remaining patients underwent SM. Conclusions: Refining high risk or life-threatening contrast misplacement, MC-3DE is more accurate than conventional MC-2DE to target safe and long-term effective septal reduction with ASA in obstructive HCM patients referred for isolated SM.

Emerging Medical Treatment for Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a common myocardial disease characterized by otherwise unexplained left ventricular hypertrophy. The main cause of disabling symptoms in patients with HCM is left ventricular outflow tract (LVOT) obstruction. This phenomenon is multifactorial, determined both by anatomical and functional abnormalities: myocardial hypercontractility is believed to represent one of its major determinants. The anatomical anomalies are targeted by surgical interventions, whereas attenuating hypercontractility is the objective of old and new drugs including the novel class of allosteric myosin inhibitors. This review summarizes the current treatment modalities and discusses the emerging therapeutical opportunities focusing on the recently developed cardiac myosin ATPase inhibitors Mavacamten and CK-274. Novel surgical and interventional approaches are also discussed.

Surgical septal myectomy outcome for obstructive hypertrophic cardiomyopathy after alcohol septal ablation

Background

Although surgical treatment of residual obstruction after alcohol septal ablation (ASA) is often challenging in patients with obstructive hypertrophic cardiomyopathy (OHCM) there are very few relevant clinical reports. Thus, outcomes of surgical septal myectomy (SSM) in this subgroup of patients remain to be determined. Therefore, this study aimed to determine the surgical and follow-up outcomes in patients with OHCM exhibiting residual obstruction after ASA.

Methods

We collected case data for 62 patients with OHCM and residual obstruction after ASA who underwent SSM at Fuwai Hospital between January 2002 and June 2019. Propensity score matching with patients having had a myectomy as the only invasive procedure—was conducted in a 1:2 ratio. Echocardiography parameters, surgery results, and follow-up outcomes were compared between the groups.

Results

The prior ASA group had a higher incidence of complete atrioventricular block (AVB) and subsequently postoperative permanent pacemaker (PPM) implantation than the primary myectomy group (9.7% vs. 1.6%, P=0.01). Two patients died within 30 days after surgery in the prior ASA group, and one patient died in the primary myectomy group, with an operative mortality rate of 3.2% and 0.8%, respectively (P=0.2). The 5-year event-free survival rate was 86.0% in the prior ASA group (median follow-up period: 3.2 years; mean: 3.9±2.6 years; maximum, 10.6 years) and 88.5% in the primary myectomy group (median follow-up period: 2.4 years; mean 2.8±1.7 years; maximum, 9.1 years) (P=0.2). During follow-up, four of 62 (6.5%) patients in the prior ASA group and one of 124 (0.8%) patients in the primary myectomy group progressed to advanced heart failure (P=0.025).

Conclusions

Patients with OHCM following ASA are at an increased risk of developing AVB after SSM. Their surgical outcomes, and long-term survival rate were satisfactory and, osimilar to those for patients having had a myectomy as the only invasive procedure. In addition, they had an increased risk of advanced heart failure after SSM in the present study.

From Prevention to Disease Perturbations: A Multi-Omic Assessment of Exercise and Myocardial Infarctions

While a molecular assessment of the perturbations and injury arising from diseases is essential in their diagnosis and treatment, understanding changes due to preventative strategies is also imperative. Currently, complex diseases such as cardiovascular disease (CVD), the leading cause of death worldwide, suffer from a limited understanding of how the molecular mechanisms taking place following preventive measures (e.g., exercise) differ from changes occurring due to the injuries caused from the disease (e.g., myocardial infarction (MI)). Therefore, this manuscript assesses lipidomic changes before and one hour after exercise treadmill testing (ETT) and before and one hour after a planned myocardial infarction (PMI) in two separate patient cohorts. Strikingly, unique lipidomic perturbations were observed for these events, as could be expected from their vastly different stresses on the body. The lipidomic results were then combined with previously published metabolomic characterizations of the same patients. This integration provides complementary insights into the exercise and PMI events, thereby giving a more holistic understanding of the molecular changes associated with each.

Septal Reduction Using Transvenous Intramyocardial Cerclage Radiofrequency Ablation: Preclinical Feasibility

•

Surgical myectomy is morbid and transcoronary alcohol septal ablation can result in geographic miss or occasional nontarget injury.

•

We developed a transvenous intraseptal radiofrequency ablation technique (cerclage ablation method) to overcome the shortcomings of surgical myectomy and alcohol septal ablation.

•

We delivered dedicated intraseptal radiofrequency ablation catheter into the ventricular septum through the coronary sinus and a septal vein. The ablated volume of myocardium was larger at higher electrode temperatures and using an irrigated-ablation mode in vitro. Cerclage ablation was successful in all in vivo attempts and induced a focal regional wall motion abnormality at later follow-up.

•

This study presents in vivo evidence of the feasibility, effectiveness, and safety of cerclage ablation method to debulk interventricular septal myocardium.

Debulking of left ventricular septal mass is typically accomplished using surgical myectomy, which is morbid, or using transcoronary alcohol septal ablation, which can result in geographic miss and occasional catastrophic nontarget coronary injury. The authors developed and tested operational parameters in vitro and vivo for a device to accomplish transvenous intraseptal radiofrequency ablation to reduce ventricular septal mass using a technique derived from mitral cerclage, which the authors call cerclage ablation. Cerclage ablation appeared feasible in vitro and safe and effective in vivo. Cerclage ablation is an attractive new approach to debulk the interventricular septum in obstructive hypertrophic cardiomyopathy. These data support clinical investigation.

Guideline-Based Referral for Septal Reduction Therapy in Obstructive Hypertrophic Cardiomyopathy Is Associated With Excellent Clinical Outcomes

BACKGROUND

The outcome of medically refractory patients with obstructive hypertrophic cardiomyopathy treated according to the American College of Cardiology/American Heart Association consensus guideline recommendations is not known. The objectives of this study were to define the short- and long-term outcomes of medically refractory obstructive hypertrophic cardiomyopathy patients undergoing alcohol septal ablation (ASA) and surgical septal myectomy (SM) with patient management in accordance with these consensus guidelines, as well as to quantify procedural risk and burden of comorbid conditions at the time of treatment.

METHODS AND RESULTS

Patients with obstructive hypertrophic cardiomyopathy referred for either ASA or SM from 2004 to 2015 were followed for the primary end point of short- and long-term mortality and compared with respective age- and sex-matched US populations. Of 477 consecutive severely symptomatic patients, 99 underwent ASA and 378 SM. Compared with SM, ASA patients were older ( P<0.001), had a higher burden of comorbid conditions ( P<0.01), and significantly higher predicted surgical mortality ( P<0.005). Procedure-related mortality was 0.3% and similarly low in both groups (0% in ASA and 0.8% in SM). Over 4.0±2.9 years of follow-up, 95% of patients had substantial improvement in heart failure symptoms to New York Heart Association class I/II (96% in SM and 90% in ASA). Long-term mortality was similar between the 2 groups with no difference compared with age- and sex-matched US populations.

CONCLUSIONS

Guideline-based referral for ASA and SM leads to excellent outcomes with low procedural mortality, excellent long-term survival, and improvement in symptoms. These outcomes occur in ASA patients despite being an older cohort with significantly more comorbidities.

Left Ventricular Outflow Tract Obstruction: A Potential Obstacle for Transcatheter Mitral Valve Therapy

Transcatheter mitral valve replacement is the focus of much enthusiasm as the future of therapy for mitral valve disease. Despite technological advances, left ventricular outflow tract (LVOT) obstruction from the valve prosthesis remains an important issue. In this review the authors discuss the pathophysiology of LVOT obstruction in both the surgical and transcatheter experience, imaging evaluation preprocedure, outcomes to date, and therapeutic options.

Transthoracic echocardiography guided percutaneous laser ablation of the interventricular septum: A successful sheep model for septal thickness reduction and one year follow-up

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a common genetic cardiovascular disease, causing breathlessness, chest pain, syncope and sudden death. One-year outcome of echo-guided transthoracic percutaneous laser ablation (TPLA) of the sheep interventricular septum was studied as a novel treatment to reduce the septal thickness. It may partially address the limitations of surgical myectomy and alcohol septal ablation in terms of trauma, safety, and efficacy.

METHODS

Twelve healthy adult sheep were randomly categorized into two groups: with and without the laser application of TPLA of the interventricular septum (IVS) at the energy level of 5 W for 3 min. Echocardiography, electrocardiography (ECG), cardiac magnetic resonance (CMR), serological and pathological examinations were performed over a 12-month follow-up.

RESULTS

After the laser ablation all animals survived with normal cardiac function; No severe complications or bundle branch block were noted. The septal thickness (3.11 ± 1.14 vs. 8.40 ± 0.45 mm, p < 0.05), regional movement of ablated IVS and longitudinal strain significantly decreased when comparing the experimental and control groups. The Troponin I level was significantly elevated after the operation, which validated immediate cardiac coagulation necrosis. On cardiac magnetic resonance (CMR) imaging, the ablated myocardium showed significant fibrosis evidenced by late gadolinium enhancement. Pathological results revealed damaged ultra-structure of the ablated myocardium and development of fibrosis.

CONCLUSIONS

TPLA is a safe and effective minimally invasive method to reduce IVS thickness in the long term, making it a potential alternative for HOCM treatment.

Timing of invasive septal reduction therapies and outcome of patients with obstructive hypertrophic cardiomyopathy

BACKGROUND

Whether early vs. delayed referral to septal reduction therapies (SRT, alcohol septal ablation or surgical myectomy) bears prognostic relevance in hypertrophic obstructive cardiomyopathy (HOCM) is unresolved. We analyzed the impact of SRT timing on the outcome of HOCM patients.

METHODS

We followed 126 patients for 5 ± 4 years after SRT (mean age 53 ± 15 years; 55 post-ASA and 71 post-SM). Based on time-to-treatment (TTT; from HOCM diagnosis to SRT), patients were divided into three groups: "<3" years, N = 50; "3-5" years, N = 25; ">5" years, N = 51.

RESULTS

Patients with TTT > 5 years were younger at diagnosis and more often had atrial fibrillation (AF). Left ventricular outflow tract (LVOT) gradients were comparable in the 3 TTT groups. Two patients died peri-operatively, all with TTT > 5. Long-term, 8 patients died (3 suddenly and 5 due to heart failure). Mortality increased progressively with TTT (2% vs. 4% vs. 12% for TTT "<3", "3-5", and ">5" years, p for trend = 0.039). Independent predictors of disease progression (new-onset AF, worsening to NYHA III/IV symptoms, re-intervention or death) were TTT ("3-5" vs. "<3" years: HR: 4.988, 95%CI: 1.394-17.843; ">5" vs. "<3" years: HR: 3.420, 95%CI: 1.258-9.293, overall p-value = 0.025), AF at baseline (HR: 1.896, 95%CI: 1.002-3.589, p = 0.036) and LVOT gradient (HR per mm Hg increase: 1.022, 95%CI: 1.007-1.024, p = 0.023).

CONCLUSIONS

Delay in SRT referral has significant impact on long-term outcome of patients with HOCM, particularly when >5 years from first detection of gradient, even when successful relief of symptoms and gradient is achieved. Earlier interventions are associated with lower complication rates and better prognosis, suggesting the importance of timely SRT to maximize treatment benefit and prevent late HOCM-related complications.

Alcohol septal ablation in hypertrophic cardiomyopathy

Alcohol septal ablation (ASA) has become an alternative to surgical myectomy in obstructive hypertrophic cardiomyopathy since it was first introduced in 1994 by Sigwart. The procedure alleviates symptoms by producing a limited infarction of the upper interventricular septum, resulting in a decrease in left ventricular outflow tract (LVOT) gradient. The technique has been improved over time and the results are comparable with those of myectomy. Initial concerns about long-term outcomes have been largely resolved. In this review, we discuss indications, technical aspects, clinical results and patient selection to ASA.

Contemporary Septal Reduction Therapy in Drug-Refractory Hypertrophic Obstructive Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a complex and relatively common genetic cardiac disease that has been the subject of intense investigation for over 50 years. Most patients with HCM are asymptomatic, but some develop symptoms, often many years after the appearance of electrocardiographic or echocardiographic evidence of left ventricular hypertrophy. Symptoms due to the left ventricular outflow tract obstruction frequently worsen over time, requiring septal reduction therapy (SRT) despite optimal medical therapy. Percutaneous transluminal septal myocardial ablation (PTSMA) and surgical myectomy are collectively known as SRT. In this review, we will focus on the emerging concept and practical implication of SRT and the available evidence on either PTSMA or surgical myectomy in the literature.

Hypertrophic obstructive cardiomyopathy: what, when, why, for whom?

Hypertrophic cardiomyopathy is the most common genetic cardiovascular disorder and is associated with symptoms of heart failure and increased risk of sudden cardiac death. The most common condition is obstruction of the left ventricular outflow tract. Surgical septal myectomy and alcohol septal ablation are the 2 accepted modes of septal reduction therapy and are indicated when there are advanced symptoms and a peak left ventricular outflow gradient ≥50 mmHg. Advantages of alcohol septal ablation are limited groin approach, reduction of obstruction of the left ventricular outflow tract and functional improvement, but there are higher chances for intracardiac device implantation and residual obstruction. Septal myectomy offers very low mortality, absolute and immediate resolution of obstruction of the left ventricular outflow tract and survival comparative to a matched general population with almost negligible residual obstruction. It is recommended that patients with obstructive hypertrophic cardiomyopathy should be treated at experienced centres.

Infarction of the septomarginal band and tricuspid papillary muscle rupture related to alcohol septal ablation for hypertrophic cardiomyopathy

We presented a 77-year-old man with hypertrophic obstructive cardiomyopathy applied with flail tricuspid leaflet and severe tricuspid regurgitation leading to right heart failure 2 months after the failed septal ablation. The ruptured anterior tricuspid papillary muscle resulted from infarction of the base of anterior papillary muscle of the right ventricle (RV) confirmed by magnetic resonance imaging. As the septomarginal band is frequently lit up by intracoronary contrast that particular attention should be paid to the RV papillary muscles. And, if the papillary muscles or the RV free wall is brightened, then the use of that septal artery should be avoided.