Meta-Analyses of Septal Reduction Therapies for Obstructive Hypertrophic Cardiomyopathy

Is There a Role for Alcohol Septal Ablation in Young Patients with Medically Refractory Hypertrophic Obstructive Cardiomyopathy?

Surgical myectomy is recommended for symptomatic hypertrophic obstructive cardiomyopathy (HOCM) after optimal pharmacological therapy. Percutaneous transluminal septal myocardial ablation (PTSMA) is reserved for high-risk adults. Symptomatic patients below 25 years underwent either surgery or PTSMA after heart-team discussion and informed consent. Echocardiography assessed gradients in surgical group. PTSMA group underwent invasive transseptal hemodynamic assessment, selective coronary angiography and super-selective cannulation of septal perforators using microcatheters. Contrast echocardiography through the microcatheter identified the myocardial target for PTSMA. Hemodynamic and electrocardiographic monitoring guided alcohol injection. Both groups were continued on beta-blockers. Symptoms, echocardiographic gradients and Brain natriuretic peptide (NTproBNP) measurements were assessed on follow-up. Twelve patients aged 5-23 years (11-98 kg) formed the study group. Indications for PTSMA in 8 patients included abnormal mitral valve anatomy warranting replacement (n = 3), Jehovah's witness (n = 2), severe neurodevelopmental and growth retardation (n = 1) and refusal of surgery (n = 2). PTSMA targeted first perforator (n = 5), second perforator (n = 2) and anomalous septal artery from left main trunk (n = 1). Outflow gradient reduced from 92.5 ± 19.7 to 33.1 ± 13.5 mmHg. At a median follow-up of 38 months (range 3-120 weeks), the peak instantaneous echocardiographic gradient was 32 ± 16.5 mmHg. Gradient reduced in four surgical patients from 86.5 ± 16.3 mmHg to 42 ± 14.7 mm Hg. All patients were in NYHA class I/II on follow-up. The mean NTproBNP in PTSMA group reduced from 6084 ± 3628 pg/ml to 3081 ± 2019 pg/ml; it was 1396 and 1795 pg/ml in surgery. PTSMA may be considered in medically refractory high-risk young patients. It relieves symptoms and reduces gradient. Though surgery is preferred in young patients, PTSMA may have a role in selected patients.

Alcohol septal ablation in patients aged 75 years or older with hypertrophic obstructive cardiomyopathy

OBJECTIVE

Outcome data for patients ≥75 years with hypertrophic obstructive cardiomyopathy (HOCM) undergoing alcohol septal ablation (ASA) are lacking. Therefore, a retrospective single-centre analysis was conducted.

METHODS

The data of all consecutive ASAs, that were performed at our institution between 1 September 1997 and 31 July 2021 in patients with HOCM with left ventricular outflow tract gradients (LVOTG) ≥50 mm Hg, were collected from patient reports. ASA was performed per institutional standards with 95% ethanol infused into a feasible septal branch. Differences regarding echocardiographic, procedural and clinical parameters at baseline and after 6 months between patients ≥75 years and <75 years were assessed.

RESULTS

We found 208 ASAs in patients ≥75 years (85.1% female; age 78.0 years (IQR 76.0-80.0)) and 1430 ASAs in patients <75 years (42.0% female; age 56.0 years (IQR 46.0-65.0)). Patients ≥75 years had lower distances in 6 min walk test (baseline: 317.0 m (IQR 242.0-389.0) vs 438.0 m (IQR 353.3-504.0); p<0.0001). Exercise-induced LVOTG calculated at follow-up was lower in patients ≥75 years (29.5 mm Hg (IQR 18.0-54.0) vs 39.5 mm Hg (IQR 23.0-73.8); p=0.0007). There were more high-degree AV blocks after ASA in patients ≥75 years (25.5% vs 13.6%; p<0.0001). The in-hospital mortality did not differ between the groups (age ≥75 years: 1.0%; age <75 years: 0.6%; p=0.6580).

CONCLUSION

ASA had similar efficacy and intrahospital mortality in patients ≥75 years compared with younger patients. Higher rates of AV block with need for permanent pacemaker implantation were observed in patients ≥75 years of age.

Percutaneous Septal Reduction Therapy in a Patient with Severely Symptomatic Hypertrophic Obstructive Cardiomyopathy: An experience from a tertiary care centre

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Mavacamten: A First-in-class Oral Modulator of Cardiac Myosin for the Treatment of Symptomatic Hypertrophic Obstructive Cardiomyopathy

Hypertrophic cardiomyopathy is the most common monogenic cardiovascular disease that is caused by sarcomeric protein gene mutations. A hallmark of the most common form of the disease is outflow obstruction secondary to systolic narrowing of the left ventricular outflow tract from septal hypertrophy, mitral valve abnormalities and, most importantly, hyperdynamic contractility. Recent mechanistic studies have identified excessive myosin adenosine triphosphatase activation and actin-myosin cross-bridging as major underlying causes. These studies have led to the development of mavacamten, a first-in-class myosin adenosine triphosphatase inhibitor and the first specific therapy for hypertrophic obstructive cardiomyopathy. Preclinical and subsequent pivotal clinical studies have demonstrated the efficacy and safety of mavacamten. A remarkable improvement among treated patients in peak oxygen consumption, functional capacity, symptom relief and post-exercise left ventricular outflow tract gradient, along with dramatic reductions in heart failure biomarkers, suggests that this new medication will be transformative for the symptom management of hypertrophic obstructive cardiomyopathy. There is also hope and early evidence that mavacamten may delay or obviate the need for invasive septal reduction therapies. In this article, we review the current evidence for the efficacy and safety of mavacamten and highlight important considerations for its clinical use.

Review of Contemporary Invasive Treatment Approaches and Critical Appraisal of Guidelines on Hypertrophic Obstructive Cardiomyopathy: State-of-the-Art Review

BACKGROUND

Hypertrophic obstructive cardiomyopathy (HOCM) is a heterogeneous disease with different clinical presentations, albeit producing similar dismal long-term outcomes if left untreated. Several approaches are available for the treatment of HOCM; e.g., alcohol septal ablation (ASA) and surgical myectomy (SM). The objectives of the current review were to (1) discuss the place of the standard invasive treatment modalities (ASA and SM) for HOCM; (2) summarize and compare novel techniques for the management of HOCM; (3) analyze current guidelines addressing HOCM management; and (4) offer suggestions for the treatment of complex HOCM presentations.

METHODS

We searched the literature and attempted to gather the most relevant and impactful available evidence on ASA, SM, and other invasive means of treatment of HOCM. The literature search yielded thousands of results, and 103 significant publications were ultimately included.

RESULTS

We critically analyzed available guidelines and provided context in the setting of patient selection for standard and novel treatment modalities. This review offers the most comprehensive analysis to-date of available invasive treatments for HOCM. These include the standard treatments, SM and ASA, as well as novel treatments such as dual-chamber pacing and radiofrequency catheter ablation. We also account for complex pathoanatomic presentations and current guidelines to offer suggestions for tailored care of patients with HOCM. Finally, we consider promising future therapies for HOCM.

CONCLUSIONS

HOCM is a heterogeneous disease associated with poor outcomes if left untreated. Several strategies for treatment of HOCM are available but patient selection for the procedure is crucial.

Hypertrophic Obstructive Cardiomyopathy: Comparison of Outcomes After Myectomy or Alcohol Ablation

Introduction and Objectives

The risk of ventricular arrhythmia and heart failure in patients with hypertrophic obstructive cardiomyopathy (HOCM) is much higher than that in the general population. More and more pieces of evidence showed that HOCM is the leading cause of sudden cardiac death in young people. We reported our experience in a study, comparing surgical myectomy, alcohol septal ablation (ASA), and medical therapy.

Methods

The original cohort included 965 consecutive patients with HOCM. The patients were divided into three groups according to treatment strategies: myectomy group (n = 502), ASA group (n = 138), and medical treatment group (n = 325). The median follow-up duration was 42.99 ± 18.32 months, and the primary endpoints were all-cause mortality and heart transplantation.

Results

Both in short- and long-term observations, surgical myectomy reduced the left ventricular outflow tract (LVOT) gradients more effectively (7 days, 16.15 ± 12.07 mmHg vs. 42.33 ± 27.76 mmHg, p < 0.05; 1 year, 14.65 ± 13.18 mmHg vs. 41.17 ± 30.76 mmHg, p < 0.05). Among the three groups, the patients in the medical treatment group were at a higher risk of mortality and cardiac transplantation (vs. the myectomy group, p < 0.001 by log-rank test; vs. the alcohol septal ablation group, p = 0.017 by log-rank test), and the myectomy group shows a lower risk of reaching the primary endpoint than the two other groups. In the multivariate Cox regression analysis, previous atrial fibrillation (AF), N terminal pro B type natriuretic peptide (NT-pro-BNP), and surgical myectomy predicted an HOCM prognosis. However, the impact of surgical myectomy on HOCM prognosis seems to be limited to the <56 years group.

Conclusions

The patients with medical treatments seemed to suffer from the highest risk of achieving an all-cause mortality and the endpoint of heart transplantation. In the long-term survival and clinical outcome, myectomy seemed better than alcohol septal ablation, especially the younger patients. Due to the less-controllable degree, periprocedural complication frequency after alcohol septal ablation was higher, compared with myectomy. Furthermore, gradients after myectomy are lower at late follow-up. To sum up, when selecting treatment strategies, the patients should be individually evaluated by a multidisciplinary team of cardiologists and surgeons.

Percutaneous transluminal septal myocardial ablation: past, present, and future

About 30% of patients with hypertrophic cardiomyopathy have a significant left ventricular pressure gradient at rest, and 60%-70% of these patients are diagnosed with hypertrophic obstructive cardiomyopathy (HOCM) because an induced pressure gradient is also present. Percutaneous transluminal septal myocardial ablation (PTSMA) is a procedure in which ethanol is used to ablate the portion of the septal myocardium that is involved in the pathogenesis of the left ventricular outflow tract pressure gradient (LVOT PG). In 1995, Sigwart et al. reported three cases of PTSMA in The Lancet. The introduction of PTSMA into clinical practice has enabled the reduction of LVOT PG and improvement of heart failure symptoms in elderly and high-risk patients with symptomatic, drug-refractory HOCM. In 1998, Faber et al. published a report in Circulation on selective septal myocardial ablation using myocardial contrast echocardiography (MCE). MCE-guided PTSMA is now recognized as the standard method of PTSMA in many countries and regions, including Europe, North America, and Asia, and is estimated to be performed on about 300 to 400 patients per year in Japan based on reports from the Japanese Circulation Society's Clinical Practice Survey. The current problems with this technique are: 1) the outcome is greatly influenced by operators' and institutional experience, and 2) it is difficult to determine in advance whether the patient is a PTSMA responder or not. Recently, advancements in imaging modalities, including cardiac computed tomography and magnetic resonance imaging, have facilitated clarification of the mechanisms of LVOT obstruction. Therefore, more appropriate decisions regarding PTSMA and surgical myectomy (SM) are now made. Better treatment selection will undoubtedly improve the prognosis of patients with drug-refractory HOCM complicated by heart failure, and further elucidation of the pathogenesis of LVOT obstruction and technical advances in PTSMA and SM are eagerly awaited.

Safety and efficacy of alcohol septal ablation in adolescents and young adults with hypertrophic obstructive cardiomyopathy

INTRODUCTION

Data regarding alcohol septal ablation (ASA) in young patients with hypertrophic obstructive cardiomyopathy (HOCM) are scarce. The purpose of our study is to evaluate the safety and efficacy of ASA in patients ≤ 25 years.

METHODS AND RESULTS

All ASAs between 2002 and 2020 at our institution were assigned to a group of patients 14-25 years of age (group 1) and a reference group > 25 years (group 2). 1,264 procedures were analysed in group 2 (58.6 ± 13.5 years) and 41 procedures in group 1 (20.9 ± 3.3 years). The baseline interventricular septal diameter (IVSD) was higher in group 1 (26.0 ± 6.5 mm vs. 21.3 ± 4.4 mm; p < 0.0001). There was no difference in baseline left ventricular outflow tract gradient (LVOTG) (group 1: 54.4 ± 24.4 mmHg; group 2: 52.4 ± 36.6 mmHg; p = n.s.). A previous cardiac device was more often observed in group 1 (31.7% vs. 9.0%; p < 0.0001). Symptoms were improved after 6 months (group 1: mean NYHA class 2.5 at baseline and 1.3 at FU; p < 0.0001; group 2: mean NYHA class 2.7 at baseline and 1.4 at FU; p <0 .0001). IVSD (group 1: 20.3 ± 8.2 mm; group 2: 16.8 ± 5.7 mm; p < 0.0001 for each group compared to baseline) and LVOTG improved during FU (group 1: 25.5 ± 20.0 mmHg; group 2: 22.1 ± 21.7 mmHg; p < 0.0001 for each group). Intrahospital mortality was 0.0% in patients 14-25 years and 0.9% in the reference group. Persistent AV-block was observed in 12.2% of the group 1 and 15.9% of the group 2 patients (p = n.s.).

CONCLUSION

ASA is safe and effective in HOCM patients 14-25 years of age in experienced centres.

Relationship Between Procedural Right Bundle Branch Block and 1-Year Outcome After Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy - A Retrospective Study

BACKGROUND

Alcohol septal ablation (ASA) is a treatment option in patients with drug-refractory symptomatic hypertrophic obstructive cardiomyopathy (HOCM). In many patients, right bundle branch block (RBBB) develops during ASA because septal branches supply the right bundle branch. However, the clinical significance of procedural RBBB is uncertain.

METHODS AND RESULTS

We retrospectively reviewed 184 consecutive patients with HOCM who underwent ASA. We excluded 40 patients with pre-existing RBBB (n=10), prior pacemaker implantation (n=15), mid-ventricular obstruction type (n=10), and those lost to follow-up (n=5), leaving 144 patients for analysis. Patients were divided into 2 groups according to the development (n=95) or not (n=49) of procedural RBBB. ASA conferred significant decreases in the left ventricular pressure gradient (LVPG) in both the RBBB and no-RBBB group (from 74±48 to 27±27 mmHg [P<0.001] and from 75±45 to 31±33 mmHg [P<0.001], respectively). None of the RBBB patients developed further conduction system disturbances. The percentage reduction in LVPG at 1 year after the procedure was significantly greater in the RBBB than no-RBBB group (66±24% vs. 49±45%; P=0.035). Procedural RBBB was not associated with pacemaker implantation after ASA, but was associated with reduction in repeat ASA (odds ratio 0.34; 95% confidence interval 0.13-0.92; P=0.045).

CONCLUSIONS

Although RBBB frequently occurs during the ASA procedure, it does not adversely affect clinical outcomes.

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.

Alcohol-induced right bundle branch block is associated with a benign outcome in HOCM after alcohol septum ablation (ASA)

INTRODUCTION

Alcohol septum ablation (ASA) is a treatment option for hypertrophic obstructive cardiomyopathy (HOCM). We examined the impact of ASA-induced bundle branch block (BBB) on clinical and hemodynamic features.

METHODS AND RESULTS

We retrospectively analysed 98 HOCM patients with regard to ASA-induced BBB. Clinical examination was performed at baseline, early after ASA and at chronic follow-up (FU). ASA reduced left ventricular outflow tract gradient (LVOTG) during chronic FU (69.2 ± 41.6 pre vs. 31.8 ± 30.3 mmHg post ASA; p < 0.05) and interventricular septal diameter (21.7 ± 3.4 pre vs. 18.7 ± 5.0 mm post ASA; p < 0.05). ASA-induced early right BBB (RBBB) until discharge was observed in 44.9% and chronic RBBB at FU in 32.7%. Left BBB (LBBB) occurred in 13.3% early after ASA and in only 4.1% at chronic FU. Chronic RBBB was associated with more pronounced exercise-induced LVOTG reduction (102.1 ± 55.2 with vs. 73.6 ± 60.0 mmHg without; p < 0.05). 6-min-walk-test (6-MWT) and NYHA class were not affected by RBBB. LBBB had no influence on LVOTG, 6-MWT and symptoms. More ethanol was injected in patients with early RBBB (1.1 ± 0.4 vs. 0.8 ± 0.3 ml without; p < 0.05), who also showed higher mean CK release (827 ± 341 vs. 583 ± 279 U/l without; p < 0.05). Pacemaker implantation during FU was necessary in 11.5% of patients with early RBBB, 3.1% with chronic RBBB, 7.7% with early LBBB and 0% with chronic LBBB (p = n.s. for BBB vs. no BBB).

CONCLUSION

ASA-induced RBBB is associated with a higher volume of infused ethanol and higher maximum CK release. RBBB does not adversely affect the clinical outcome or need for pacemaker implantation but was associated with higher exercise-induced LVOTG reduction during chronic FU.

Alcohol Septal Ablation versus Septal Myectomy Treatment of Obstructive Hypertrophic Cardiomyopathy: A Systematic Review and Meta-Analysis

Surgical myectomy (SM) and alcohol septal ablation (ASA) are two invasive therapies for symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM), despite medical therapy. This meta-analysis aims to compare the efficacy of the two procedures. We searched all electronic databases until February 2020 for clinical trials and cohorts comparing clinical outcomes of ASA and SM treatment of patients with HOCM. The primary endpoint was all-cause mortality, cardiovascular (CV) mortality, sudden cardiac death (SCD), re-intervention, and complications. Secondary endpoints included relief of clinical symptoms and drop of left ventricular outflow tract (LVOT) gradient. Twenty studies (4547 patients; 2 CTs and 18 cohorts) comparing ASA vs. SM with a mean follow-up of 47 ± 28.7 months were included. Long term (8.72 vs. 7.84%, p = 0.42) and short term (1.12 vs. 1.27%, p = 0.93) all-cause mortality, CV mortality (2.48 vs. 3.66%, p = 0.26), SCD (1.78 vs. 0.76%, p = 0.20) and stroke (0.36 vs. 1.01%, p = 0.64) were not different between procedures. ASA was associated with lower peri-procedural complications (5.57 vs. 10.5%, p = 0.04) but higher rate of re-interventions (10.1 vs. 0.27%; p < 0.001) and pacemaker dependency (12.4 vs. 4.31%, p = 0.0004) compared to SM. ASA resulted in less reduction in LVOT gradient (-47.8 vs. -58.4 mmHg, p = 0.01) and less improvement of clinical symptoms compared to SM (New York Heart Association (NYHA) class III/IV, 82.4 vs. 94.5%, p < 0.001, angina 53.2 vs. 84.2%, p = 0.02). Thus, ASA and SM treatment of HOCM carry a similar risk of mortality. Peri-procedural complications are less in alcohol ablation but re-intervention and pacemaker implantations are more common. These results might impact the procedure choice in individual patients, for the best clinical outcome.

Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disease. The disease is characterized by marked variability in morphological expression and natural history, ranging from asymptomatic to heart failure or sudden cardiac death. Left ventricular hypertrophy and abnormal ventricular configuration result in dynamic left ventricular outflow obstruction in most patients. The goal of pharmacological therapy in HCM is to alleviate the symptoms, and it includes pharmacotherapies and septal reduction therapies. In this review, we summarize the relevant clinical issues and treatment options of HCM.

Current state of the roles of alcohol septal ablation and surgical myectomy in the treatment of hypertrophic obstructive cardiomyopathy

Hypertrophic cardiomyopathy is a genetically determined disorder resulting in left ventricular hypertrophy. In a majority of the estimated 20 million people affected worldwide, left ventricular outflow obstruction is present at rest or with provocation. The presence and degree of obstruction influence the symptomatic presentation, treatment strategies and prognosis of affected individuals. Pharmacologic therapy with beta-adrenergic blocking drugs and calcium channel blockers is the principal treatment strategy in symptomatic patients with left ventricular outflow obstruction but is ineffective in many patients. When symptoms of exertional shortness of breath, chest pain and/or syncope prove refractory to medical therapy and there is persisting left ventricular outflow obstruction, or when there is drug intolerance, septal reduction strategies (surgical myectomy and alcohol septal ablation) are quite effective. Selection of the optimal septal reduction strategy for a given patient has become controversial and is determined largely by the medical system providing treatment strategies for the patient. Regretably, there are no randomized trials comparing myectomy and ablation and none are anticipated. The comprehensive Hypertrophic Cardiomyopathy Guideline Statements published in 2011 and 2014 differ significantly with the earlier statement favoring surgical myectomy and the more recent statement giving equal class I status to the two septal reduction strategies in adult patients with drug-refractory symptoms. Recently published studies of long-term follow-up of patients after alcohol septal ablation in Europe, where surgical myectomy is rarely performed, confirm long-term safety and effectiveness with survival free of cardiac events exceeding 96% at 15 years. The lesser degree of discomfort and more rapid recovery associated with the minimally invasive catheter-based alcohol ablation procedure coupled with the recently published long-term safety data favor an increased use of this strategy in symptomatic adult patients with hypertrophic obstructive cardiomyopathy (HOCM).

Percutaneous transluminal septal myocardial ablation for hypertrophic obstructive cardiomyopathy through non-left anterior descending septal perforators

Percutaneous transluminal septal myocardial ablation (PTSMA) has become a significant treatment for symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM) despite maximal medical therapy. The target septal arteries usually arise from the left anterior descending artery (LAD). However, when septal perforators do not originate from the LAD, non-LAD septal perforators should be included as candidate-target septal branches that feed the hypertrophic septal myocardium, causing left ventricular outflow tract (LVOT) obstruction. Data pertaining to the procedure remain limited. We aimed to investigate PTSMA through the non-LAD septal perforators in patients with HOCM. In this case series review, we evaluated the baseline characteristics, echocardiographic features, and angiographic features, as well as symptoms and pressure gradient before and after PTSMA through the non-LAD septal perforators. Among 202 consecutive patients who underwent PTSMA for HOCM with LVOT obstruction, 21 had non-LAD septal branches that fed the hypertrophic septal myocardium and received alcohol ablation. Non-LAD septal perforators could be used as an alternative route for PTSMA in patients who experienced ineffective ablation of the septal branch that arises from the LAD. This unique procedure may improve response rates and overall outcomes of patients with HOCM.

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.

Long-term outcome of conservative and invasive treatment in patients with hypertrophic obstructive cardiomyopathy

Background and objective: Treatment for patients with hypertrophic obstructive cardiomyopathy (HOCM) can be either conservative or invasive (alcohol septal ablation (ASA) and myectomy). As there is no clear consensus on the long-term effects of these different strategies, the aim was to compare the long-term outcome in a large tertiary referral university hospital. Methods: We retrospectively included 106 HOCM patients. Twenty-nine (27.4%) patients were treated conservatively, 25 (23.6%) underwent ASA and 52 (49.0%) myectomy. Endpoints were all-cause mortality and sudden cardiac death (SCD)-related events (including SCD, aborted SCD and appropriate ICD shocks). Kaplan-Meier survival analysis and Cox proportional hazard regression models were used. Results: The mean follow-up period was 7.7 ± 4.9 years. Overall, there was no significant difference in survival between the three treatment strategies (p = 0.7). Annual rates of SCD-related events at 5 years and the complete follow-up period were significantly higher (p = 0.034) after conservative treatment (4.9%/year and 2.7%/year, respectively) compared to ASA (0.9%/year, 0.5%/year) and myectomy (1.0%/year, 0.6%/year). Independent predictors of SCD-related events were: conservative treatment (HR 10.66; 1.88-60.55), a known mutation (HR 9.36; 1.43-61.20), left ventricular wall thickness (LVWT) > 30 mm (HR 6.48; 1.05-39.92) and non-sustained VT (HR 16.82; 2.29-123.29). Invasive treatment resulted in a significant higher proportion of patients requiring pacing (p = 0.033). Conclusions: Long-term mortality rates for patients with HOCM are similarly low between treatment groups. However, conservative treatment was associated with SCD-related events, as were known mutations, increased LVWT and non-sustained VT. Invasive treatment was associated with a higher need for implantation of a pacemaker.

Outcome of patients ≥ 60 years of age after alcohol septal ablation for hypertrophic obstructive cardiomyopathy

INTRODUCTION

The outcome of patients ≥ 60 years of age after alcohol septal ablation (ASA) for obstructive hypertrophic cardiomyopathy (HCM) remains unresolved. We sought to determine the long-term survival and the causes of death in this population.

MATERIAL AND METHODS

We enrolled 156 consecutive patients (69 ±6 years, 69% women, follow-up: 4.8 ±3.5 years) who underwent ASA at ≥ 60 years of age.

RESULTS

The 30-day mortality rate was 1.3%. At the last check-up, 81% of patients were in New York Heart Association class ≤ 2 and 76% had a left ventricular outflow tract gradient (LVOG) ≤ 30 mm Hg. A total of 39 patients died (51% of cardiovascular causes, 44% of non-cardiovascular causes, 5% of unknown causes) during the 734 patient-years. The annual sudden mortality, the sudden mortality and the all-cause mortality rates were 0.5%, 1.1%, and 4.8%, respectively. The all-cause mortality was higher compared to the age- and sex-matched general population (p = 0.002).

CONCLUSIONS

Alcohol septal ablation was safe and effective in the long-term follow-up. We observed a reduced life expectancy compared to the age- and sex-matched general population. Mortality was almost equally due to cardiovascular and non-cardiovascular causes of death.

Utility of preprocedural multidetector computed tomography in alcohol septal ablation for hypertrophic obstructive cardiomyopathy

Preprocedural computed tomography (CT) imaging appears to provide an advantage in localization of the appropriate septal branch targeted for alcohol septal ablation (ASA). The objective of this study was to compare the clinical backgrounds, procedural characteristics, and outcomes of patients who underwent ASA with preprocedural CT assessment against those without CT assessment. Thirty consecutive patients with obstructive hypertrophic cardiomyopathy who underwent ASA were retrospectively included. Patients who underwent preprocedural CT (CT-guided ASA group, n = 11) were compared with patients who underwent ASA without CT (traditional ASA group, n = 19). The CT-guided ASA group had a significantly lower number of approached target vessels (1 [interquartile range {IQR}, 1-2] vs. 2 [IQR, 2-3], P = 0.036) and non-ablated target vessels (0 [IQR, 0-1] vs. 1 [IQR, 0-2], P = 0.031) than the traditional ASA group. There were no differences between the two groups in total fluoroscopy time, the amount of delivered radiation dose, and the volume of contrast medium used during the procedures. There were also no differences between the two groups in procedural success rate and improvement of left ventricular outflow tract gradient and New York Heart Association functional class at 1 month follow-up. CT had a significant impact on the ASA procedure diminishing the number of target vessels, and could be a reliable assessment modality to build its procedural strategy.

Minimally Invasive Versus Full-Sternotomy Septal Myectomy for Hypertrophic Cardiomyopathy

OBJECTIVE

Septal myectomy remains the criterion standard for the treatment of patients with hypertrophic obstructive cardiomyopathy refractory to medical therapy. There have been few reports of minimally invasive approaches. This study compared a minimally invasive septal myectomy performed at our institution with the traditional full-sternotomy approach.

METHODS

Patients receiving a stand-alone septal myectomy were retrospectively reviewed from November 1999 to December 2016 (N = 120). Patients were stratified by surgical approach: traditional full sternotomy (n = 34) and ministernotomy (n = 86). Preoperative and perioperative variables were compared as well as follow-up symptomatic and echocardiographic outcomes.

RESULTS

Both groups had a significant decrease in New York Heart Association class heart failure symptoms (P < 0.001). At a mean ± SD follow-up time of 2.0 ± 3.4 years, postoperative New York Heart Association class distribution was similar between ministernotomy and full sternotomy (P = 0.684). Follow-up resting left ventricular outflow tract gradient was also similar between ministernotomy and full sternotomy (11 mm Hg ± 15 vs 9 mm Hg ± 13, P = 0.381). Perioperatively, ministernotomy was not significantly different from full sternotomy in median cardiopulmonary bypass time (81 minutes vs 78 minutes, P = 0.101) but had a slightly longer median cross-clamp time (39 minutes vs 35 minutes, P = 0.017). Major complications were similar in the two groups. There was one 30-day mortality in the full-sternotomy group, but no in-hospital deaths.

CONCLUSIONS

Septal myectomy performed using a minimally invasive approach has similar outcomes to the criterion standard operation done through a full sternotomy. It represents a feasible option for patients with hypertrophic obstructive cardiomyopathy unresponsive to medications.

Disclosure of diagnosis to at-risk relatives by individuals diagnosed with hypertrophic cardiomyopathy (HCM)

Hypertrophic cardiomyopathy (HCM) affects 1 in 200 people and is the most common cause of sudden cardiac death in the young. Given that HCM usually is inherited in an autosomal dominant pattern, an HCM diagnosis has implications for biologically related family members. The purpose of this study was to explore probands' disclosure of an HCM diagnosis with these biologically related, at-risk family members. An online survey was posted on the website of the Hypertrophic Cardiomyopathy Association (HCMA), an advocacy and support group for HCM patients and their families. Descriptive statistics were used to summarize responses to closed-ended questions and demographics. Using an iterative content analysis with the constant comparison approach, we analyzed the responses to open-ended questions inquiring about the nature and role of disclosure communication with at-risk relatives. A total of 315 individuals with a self-reported diagnosis of HCM completed the survey. Most participants (98%) disclosed their diagnosis to at-risk family members. Sixty-four percent disclosed to family members less than 1 year after diagnosis. Participants also disclosed potential treatment options (74.6%) and the emotional impact of the diagnosis (39%). HCM specialists were ranked by participants as being the most helping in explaining the benefit of genetic counseling, while genetic counselor were ranked as least helpful. Emerging themes address the need to encourage screening and genetic testing among family members and to identify external educational resources for use during the disclosure process. Importantly, our study found that the process of disclosure varies based on individuals' experiences and family communication dynamics. However, almost all participants expressed the importance of disclosing the diagnosis of HCM as well as the importance of being screened and expressed needs for additional support during the disclosure process.

Ultrasonic Cavitation-Enabled Treatment for Therapy of Hypertrophic Cardiomyopathy: Proof of Principle

Ultrasound myocardial cavitation-enabled treatment was applied to the SS-16^BN rat model of hypertrophic cardiomyopathy for proof of the principle underlying myocardial reduction therapy. A focused ultrasound transducer was targeted using 10-MHz imaging (10 S, GE Vivid 7) to the left ventricular wall of anesthetized rats in a warmed water bath. Pulse bursts of 4-MPa peak rarefactional pressure amplitude were intermittently triggered 1:8 heartbeats during a 10-min infusion of a microbubble suspension. Methylprednisolone was given to reduce initial inflammation, and Losartan was given to reduce fibrosis in the healing tissue. At 28 d post therapy, myocardial cavitation-enabled treatment significantly reduced the targeted wall thickness by 16.2% (p <0.01) relative to shams, with myocardial strain rate and endocardial displacement reduced by 34% and 29%, respectively, which are sufficient for therapeutic treatment. Premature electrocardiogram complexes and plasma troponin measurements were found to identify optimal and suboptimal treatment cohorts and would aid in achieving the desired impact. With clinical translation, myocardial cavitation-enabled treatment should fill the need for a new non-invasive hypertrophic cardiomyopathy therapy option.

Obstructive Hypertrophic Cardiomyopathy with Concomitant Mitral Regurgitation Treated with a Septal Myectomy and MV Repair: A Case Report

Case presentation

Hypertrophic cardiomyopathy (HCM) is the most common and very heterogeneous genetic cardiac disease with a different clinical presentation and prognosis. The overall prevalence of the disease is estimated between 0.05-0.2% of the population. Left ventricular outflow obstruction at rest is present in about 20% of patients. Most of the patients have a normal life expectancy, however high risk patients might develop heart failure, atrial fibrillation, ventricular arrhythmias and sudden cardiac death.

We present the case of 47-year-old Caucasian man who was hospitalized at our clinic with a history of chest pain and shortness of breath on physical activity in the last six months, which caused significant limitations of his life quality. Hypertrophic obstructive cardiomyopathy was diagnosed in 2011, when the patient was put on therapy with beta blocker. Transthoracic echocardiography revealed normal systolic function, presence of systolic anterior mitral valve motion (SAM) with moderate mitral regurgitation (MR). There was a significant concentric left ventricular hypertrophy predominantly located in the ventricular septum. The intraventricular gradient at rest was 77.8 mmHg. MRI of the heart confirmed significant LV hypertrophy with regions of fibrosis at the septum. The patient shortness of breath worsened progressively in the last month (NYHA III) despite optimized medical treatment with maximal beta blocker dose. Surgical approach with septal myectomy was performed with mitral valve repair. There were no operative complications, with excellent postoperative recovery and complete symptoms resolution. Control Doppler echocardiograms revealed LVOT rest gradient reduction to 34 mmHg. The good operative results were still present 9 months after the intervention.

Our case confirmed that septal myectomy with MV repair is an excellent treatment approach in young patient with obstructive hypertrophic cardiomyopathy and mitral valve involvement refractory to medical treatment.

Interventional therapies for relief of obstruction in hypertrophic cardiomyopathy: discussion and proposed clinical algorithm

Hypertrophic cardiomyopathy (HCM), a disease formerly thought rare in clinical practice, is now believed to affect as many as 1 in 300 individuals, regardless of race or gender. Rising awareness, coupled with advanced imaging and the development of dedicated HCM centers of excellence, has led to more patients coming to clinical presentation. While some are diagnosed at a young age, others are diagnosed in middle age or well into advanced age. Unfortunately, many such patients have progressed clinically to overt heart failure, or have some combination of advanced symptoms including dyspnea, angina, pre-syncope or syncope, palpitations, and edema. Anatomic subsets, including those with mid-ventricular obstruction or apical disease, with or without apical aneurysm, have also been seen in increasing frequency. Fortunately, both percutaneous and surgical invasive options are available across the spectrum of disease severity and anatomy, with outcomes continuing to improve as the techniques and experience evolve. Advances in both approaches allow targeted and individualized treatment of the majority of these patients. This review will focus on interventional approaches to relief of obstruction, and will provide a current clinical algorithm from our center for determining when an interventional approach may be recommended or optimal over a surgical approach, and vice versa.

Hypertrophic Cardiomyopathy-Past, Present and Future

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy with a prevalence of 1 in 500 in the general population. Since the first pathological case series at post mortem in 1957, we have come a long way in its understanding, diagnosis and management. Here, we will describe the history of our understanding of HCM including the initial disease findings, diagnostic methods and treatment options. We will review the current guidelines for the diagnosis and management of HCM, current gaps in the evidence base and discuss the new and promising developments in this field.

Multiple ultrasound cavitation-enabled treatments for myocardial reduction

Background

Ultrasound myocardial cavitation enabled treatment (MCET) is an image-guided method for tissue reduction. In this study, a strategy of fractionated (multiple) treatments was tested for efficacy.

Methods

Dahl SS rats were anesthetized and prepared for treatment with a focused ultrasound transducer in a warm water bath. Aiming at the anterior left ventricular wall was facilitated by imaging with a 10 MHz phased array (10S, GE Vivid 7, GE Vingmed Ultrasound, Horten, Norway). MCET was accomplished at 1.5 MHz by pulse bursts of 4 MPa peak rarefactional pressure amplitude, which were intermittently triggered 1:8 from the ECG during infusion of a microbubble suspension for cavitation nucleation. Test groups were sham, a 200 s treatment, three 200 s treatments a week apart, and a 600 s treatment. Treatment outcome was observed by plasma troponin after 4 h, echocardiographic monitoring and histology at 6 wk.

Results

The impacts of the fractionated treatments summed to approximately the same as the long treatment; e. g. the troponin result was 10.5 ± 3.2 for 200 s, 22.7 ± 5.4 (p < 0.001) for the summed fractionated treatments and 29.9 ± 6.4 for 600 s (p = 0.06 relative to the summed fractionated). While wall thickness was not reduced for the fractionated treatment, tissue strain was reduced by 35% in the target area relative sham (p < 0.001).

Conclusion

The ability to fractionate treatment may be advantageous for optimizing patient outcome relative to all-or nothing therapy by surgical myectomy or alcohol ablation.

Analysis of three-dimensional endocardial and epicardial strains from cardiac magnetic resonance in healthy subjects and patients with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic disease that leads to left ventricle (LV) hypertrophy with or without the presence of LV outflow tract obstruction. The aim of this study was to find an easy and useful indicator based on cardiac magnetic resonance (CMR) images for control subjects and patients with and without obstruction. CMR scans were performed for 19 control subjects and 19 HCM patients. Endocardial strain was defined as [Formula: see text], with [Formula: see text] being the length of endocardium at end-diastole (end-systole); similarly for epicardial strain ([Formula: see text]). The strains were evaluated in cine CMR two-, three- and four-chamber views. Six atrioventricular junction (AVJ) points from three CMR views were semi-automatically tracked. The peak systolic velocity (Sm1), peak early diastolic velocity and late diastolic velocity (Em, Am) were extracted and analysed. Compared with control subjects, HCM patients had significantly smaller three-dimensional strains and AVJ motion incorporating measurements from three long-axis views (all P < 0.05). Moreover, ROC analysis found that three-dimensional global epicardial strain <17.2% had the best sensitivity 94.4% and specificity 94.7% to differentiate HCM from control (AUC = 0.97). Therefore, three-dimensional endocardial and epicardial strains provide an easy and effective approach to manage and triage hypertrophic cardiomyopathy patients.

Treating a Structural Heart Disease Using a Non-structural Approach: Role of Cardiac Pacing in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiovascular disease characterized by a thickened non-dilated ventricle in the absence of another cardiac or systemic condition. Its most important hemodynamic consequence is left ventricular outflow tract (LVOT) obstruction. The primary management strategy of this condition is surgical septal myectomy, but an acceptable alternative treatment in patients who are not suitable for (or who refuse) surgery is alcohol septal ablation (ASA). However, in patients with unfavorable coronary anatomy which precludes ASA (i.e. absence of major septal perforator branch of the left anterior descending (LAD) artery), another reasonable option is dual chamber pacemaker implantation to decrease LVOT outflow gradient. A 77-year-old female, known hypertensive, diabetic with a history of coronary artery disease, presented with 1-week history of worsening chest pain and shortness of breath. She was admitted as a case of acute coronary syndrome and pneumonia. On workup, 2DED revealed hypertrophic obstructive cardiomyopathy (HOCM) with a demonstrated systolic anterior motion (SAM) of the mitral valve with a peak instantaneous gradient of 194 mm Hg across the basal LV cavity. The patient refused surgical myectomy, and ASA was the preferred treatment option. On coronary angiography, there was an incidental finding of absent major septal perforator branch of the LAD coronary artery, rendering her unsuitable for septal ablation. She was referred to electrophysiology for evaluation. She underwent dual chamber pacemaker implantation and documented significant decrease in the peak instantaneous gradient from 194 to 37 mm Hg, with complete obliteration of SAM and improvement in overall wall motion. She remained stable and asymptomatic after pacemaker insertion until her recent outpatient follow-up (1 year after implantation). We present a case of HCM with congenitally absent major septal perforator branch coronary artery treated with dual chamber pacemaker implantation. To our knowledge, this is the first reported angiographically absent first (major) septal perforator coronary anatomy in the setting of HCM, and also the first description of dual chamber pacemaker implantation to relieve the LVOT obstruction. Although the role of dual chamber pacing has become limited in HCM because surgical myectomy and septal ablation have resulted in better decrease in LV outflow gradient and symptom improvement, this modality remains essential and may still be considered as the treatment strategy-of-choice in patients who are unsuitable for surgical myectomy and ASA.

Twenty Years of Alcohol Septal Ablation in Hypertrophic Obstructive Cardiomyopathy

Hypertrophic obstructive cardiomyopathy is the most common genetic cardiac disease and is generally characterised by asymmetric septal hypertrophy and intraventricular obstruction. Patients with severe obstruction and significant symptoms that persist despite optimal medical treatment are candidates for an invasive septal reduction therapy. Twenty years after its introduction, percutaneous transluminal alcohol septal ablation has been increasingly preferred for septal reduction in patients with drug refractory hypertrophic obstructive cardiomyopathy. Myocardial contrast echocardiography and injection of reduced alcohol volumes have increased safety, while efficacy is comparable to the surgical alternative, septal myectomy, which has for decades been regarded as the 'gold standard' treatment. Data on medium- and long-term survival show improved prognosis with survival being similar to the general population. Current guidelines have supported its use by experienced operators in centres specialised in the treatment of patients with hypertrophic obstructive cardiomyopathy.

Long-Term Outcome of Alcohol Septal Ablation for Obstructive Hypertrophic Cardiomyopathy in the Young and the Elderly

OBJECTIVES

The aim of this study was to compare outcomes of alcohol septal ablation (ASA) in young and elderly patients with obstructive hypertrophic cardiomyopathy (HCM).

BACKGROUND

The American College of Cardiology Foundation/American Heart Association guidelines reserve ASA for elderly patients and patients with serious comorbidities. Information on long-term age-specific outcomes after ASA is scarce.

METHODS

This cohort study included 217 HCM patients (age 54 ± 12 years) who underwent ASA because of symptomatic left ventricular outflow tract obstruction. Patients were divided into young (age ≤55 years) and elderly (age >55 years) groups and matched by age in a 1:1 fashion to nonobstructive HCM patients.

RESULTS

Atrioventricular block following ASA was more common in elderly patients (43% vs. 21%; p = 0.001), resulting in pacemaker implantation in 13% and 5%, respectively (p = 0.06). Residual left ventricular outflow tract gradient, post-procedural New York Heart Association functional class, and necessity for additional septal reduction therapy was comparable between age groups. During a follow-up of 7.6 ± 4.6 years, 54 patients died. The 5- and 10-year survival following ASA was 95% and 90% in patients age ≤55 years and 93% and 82% in patients age >55 years, which was comparable to their control groups. The annual adverse arrhythmic event rate following ASA was 0.7%/year in young patients and 1.4%/year in elderly patients, which was comparable to their control groups.

CONCLUSIONS

ASA is similarly effective for reduction of symptoms in young and elderly patients; however, younger patients have a lower risk of procedure-related atrioventricular conduction disturbances. The long-term mortality rate and risk of adverse arrhythmic events following ASA are low, both in young and elderly patients, and are comparable to age-matched nonobstructive HCM patients.

Septal Ablation for Hypertrophic Obstructive Cardiomyopathy: Transcoronary and Endocardial Approach

Septal reduction therapy is the gold standard treatment method for symptomatic, hypertrophic obstructive cardiomyopathy. Although surgical myectomy is a well-established and effective technique with decades of experience in its application, use of transcoronary alcohol septal ablation has increased precipitously owing to the less-invasive nature of the procedure. Moreover, endocardial septal ablation therapy is a relatively newly defined modality, and outcomes of the procedure are not clearly elucidated yet. In this review, we aimed to present nonsurgical septal reduction approaches in patients with hypertrophic obstructive cardiomyopathy.

Update on hypertrophic cardiomyopathy and a guide to the guidelines

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiovascular disorder, affecting 1 in 500 individuals worldwide. Existing epidemiological studies might have underestimated the prevalence of HCM, however, owing to limited inclusion of individuals with early, incomplete phenotypic expression. Clinical manifestations of HCM include diastolic dysfunction, left ventricular outflow tract obstruction, ischaemia, atrial fibrillation, abnormal vascular responses and, in 5% of patients, progression to a 'burnt-out' phase characterized by systolic impairment. Disease-related mortality is most often attributable to sudden cardiac death, heart failure, and embolic stroke. The majority of individuals with HCM, however, have normal or near-normal life expectancy, owing in part to contemporary management strategies including family screening, risk stratification, thromboembolic prophylaxis, and implantation of cardioverter-defibrillators. The clinical guidelines for HCM issued by the ACC Foundation/AHA and the ESC facilitate evaluation and management of the disease. In this Review, we aim to assist clinicians in navigating the guidelines by highlighting important updates, current gaps in knowledge, differences in the recommendations, and challenges in implementing them, including aids and pitfalls in clinical and pathological evaluation. We also discuss the advances in genetics, imaging, and molecular research that will underpin future developments in diagnosis and therapy for HCM.

Novel Approach Targeting the Complex Pathophysiology of Hypertrophic Cardiomyopathy: The Impact of Late Sodium Current Inhibition on Exercise Capacity in Subjects with Symptomatic Hypertrophic Cardiomyopathy (LIBERTY-HCM) Trial

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disorder, with an overall prevalence of at least 1:500 in the adult population although only a fraction of affected patients come to clinical recognition. It is also the most common cause of sudden cardiac death in young adults and a major cause of morbidity caused by chronic heart failure symptoms. However, more than half a century since the original description of the disease, there is no currently approved therapy for the treatment of patients with HCM, and to date there have been only 5 randomized studies of medical therapies in HCM. As such, unmet medical need in HCM has been highlighted by the National Heart, Lung, and Blood Institute (NHLBI) as a research priority. Encouragingly, the infrastructure needed to conduct rigorous clinical trials in HCM has recently emerged because of the heightened awareness and understanding of the disease, development of clinical centers of excellence, and advances in diagnostic imaging. In this article, we will discuss the complex pathophysiology of HCM, review the current therapeutic landscape, describe new mechanistic insights into the central role of the late sodium current in HCM, and introduce the scientific rationale and execution of the Impact of Late Sodium Current Inhibition on Exercise Capacity in Subjects with Symptomatic Hypertrophic Cardiomyopathy (LIBERTY-HCM) trial, the largest randomized, double-blind, placebo controlled clinical trial, now underway, designed to evaluate the effect of a novel pharmacological approach in patients with symptomatic HCM.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02291237.

Short and long-term outcomes of alcohol septal ablation with the trans-radial versus the trans-femoral approach: A single center-experience

BACKGROUND

Although the trans-radial approach (TR) has been applied to various subsets of patients in percutaneous coronary intervention, the feasibility, efficacy, acute procedural and long-term outcomes of TR versus trans-femoral approach (TF) for alcohol septal ablation (ASA) have not yet been determined.

OBJECTIVES

The aim of this study was to compare the short and long-term outcomes of ASA with the TR approach compared to the TF approach.

METHODS

We retrospectively analyzed 240 patients who underwent an ASA procedure at our institution from November 1999 to November 2015. The TR approach was performed in 172 cases and the TF approach in the remaining 68 cases.

RESULTS

The use of TR approach progressively increased from 62% in 1999-2005 to 91% in 2011-2015 (p=0.0001). The TF and TR group had similar age, baseline NYHA class (NYHA 3 or 4) and mean left ventricular outflow tract peak gradient before ASA. Total contrast used (TR: 73.2±47.2ml; TF: 88.7±49.3ml, p=0.11), total radiation Air kerma area product (TR: 43.7±48.0Gycm(-2); TF: 55.9±48.2Gycm(-2); p=0.39) and peak left ventricular outflow tract gradient immediately after ASA (TR: 19.1±19.6mmHg; TF: 20.4±18.0mmHg, p=0.63) were similar in both groups. Procedural success was 91.9% and 91.2% in the TR and TF groups, respectively (p=0.53). At 30days, there was 2 intra-hospital death (1 in TF and 1 in TR), 1 major stroke in the TF group and 1 coronary artery dissection in the TR group. Vascular complications were less frequent in the TR group (0.58% vs. 7.3%; p=0.002). The mean length of follow-up was 4.56±4.34years (IQR 0.69-8.2; median 2.92years; maximum: 15.5years). By Kaplan-Meier estimate, the observed survival in the overall cohort was comparable to the expected survival for a sex and age-matched comparable general French population at 10years (86.9 vs. 83.6%, p=0.88). Survival was similar between the TR and TF group (92.1% vs. 89.7% at 6years, respectively; p=0.71).

CONCLUSIONS

Alcohol septal ablation from the radial approach can be performed with similar acute and long-term success, but with lower vascular complications compared to the femoral approach.

Long-term clinical and echocardiographic outcomes of extensive septal myectomy for hypertrophic obstructive cardiomyopathy in Chinese patients

Background

There has been limited data addressing outcomes of extensive septal myectomy in Chinese patients with hypertrophic obstructive cardiomyopathy (HOCM). In this study, the objective was to evaluate the clinical and echocardiographic outcomes of extensive septal myectomy in a relative large number of Chinese HOCM patients over long-term follow-up.

Methods

We retrospectively studied 139 consecutive HOCM patients (age 43 ± 15 years, 37 % male) who underwent extensive left ventricular septal myectomy. During the perioperative period, all patients were examined by echocardiography. All-cause death and cardiac death were considered as primary endpoints during follow-up. Perioperative data was obtained by retrospective review of institutional surgical databases. Follow-up data of echocardiography and clinical status was recorded through outpatient interview.

Results

Perioperative events consisted of arrhythmia, retraction injury to aortic valve leaflets, pleural effusion, and hemodialysis and the use of intra-aortic balloon pump. There was no in-hospital mortality. The follow-up period averaged 5.6 ± 0.9 years and overall survivals were 100.0, 99.3, 99.3, 98.5 and 97.8 % at 1, 2, 3, 4 and 5 years, respectively. Left ventricular outflow tract (LVOT) gradient decreased form preoperative 84 ± 17 mmHg to 12 ± 3 mmHg at 2.5 years after surgery and it further reduced to 6 ± 3 mmHg at 5 years after surgery (P < 0.05). Compared with the preoperative levels, interventricualr septal thickness decreased by 32 % while diastole left ventricular inner diameter approximately increased by 10 % and ejection fraction (EF) was significantly elevated during follow-up (P < 0.05). By echocardiography detection, mitral regurgitation was ameliorated for HOCM patients after surgery. There was significant improvement in New York Heart Association (NYHA) class. The proportion of NYHA III and IV decreased from preoperative 58 to 19 % at 2.5 years after surgery and it reduced to 11 % at 5 years after operation.

Conclusion

Extensive septal myectomy offers minimal operative risk and provides long-term relief for LVOT obstruction in Chinese HOCM patients.

Incidence of Atrial Fibrillation following Alcohol Septal Ablation for Hypertrophic Cardiomyopathy

BACKGROUND

Patients with hypertrophic cardiomyopathy (HCM) are at a fourfold to sixfold higher risk of developing atrial fibrillation (AF) compared to the general population, though incidence rates among patients undergoing alcohol septal ablation (ASA) are not well characterized. The purpose of this study was to evaluate atrial fibrillation incidence following ASA.

METHODS

We studied 132 consecutive HCM patients without comorbid AF that underwent 154 ASA procedures. The incidence of AF in follow-up was assessed through chart abstraction including electrocardiography. Survival free of AF was estimated using Kaplan-Meier methodology.

RESULTS

Over a mean follow-up of 3.6 ± 2.7 years (maximum 11.3 years), 10 (7.6%) patients developed new-onset AF. Of those who developed AF, both resting and provoked left ventricular outflow tract (LVOT) gradients had improved significantly (difference -79.78 mm Hg, P ≤ 0.005). Severity of mitral regurgitation improved in 7 (70%) patients. Survival free of AF was estimated to be 99.1%, 93.7%, and 91.7% at 1, 3, and 5 years.

CONCLUSIONS

Despite relieving LVOT obstruction and improving mitral regurgitation severity via ASA, new-onset AF remained a common complication of hypertrophic cardiomyopathy.

Long-term clinical outcome after alcohol septal ablation for obstructive hypertrophic cardiomyopathy: results from the Euro-ASA registry

AIMS

The first cases of alcohol septal ablation (ASA) for obstructive hypertrophic cardiomyopathy (HCM) were published two decades ago. Although the outcomes of single-centre and national ASA registries have been published, the long-term survival and clinical outcome of the procedure are still debated.

METHODS AND RESULTS

We report long-term outcomes from the as yet largest multinational ASA registry (the Euro-ASA registry). A total of 1275 (58 ± 14 years, median follow-up 5.7 years) highly symptomatic patients treated with ASA were included. The 30-day post-ASA mortality was 1%. Overall, 171 (13%) patients died during follow-up, corresponding to a post-ASA all-cause mortality rate of 2.42 deaths per 100 patient-years. Survival rates at 1, 5, and 10 years after ASA were 98% (95% CI 96-98%), 89% (95% CI 87-91%), and 77% (95% CI 73-80%), respectively. In multivariable analysis, independent predictors of all-cause mortality were age at ASA (P < 0.01), septum thickness before ASA (P < 0.01), NYHA class before ASA (P = 0.047), and the left ventricular (LV) outflow tract gradient at the last clinical check-up (P = 0.048). Alcohol septal ablation reduced the LV outflow tract gradient from 67 ± 36 to 16 ± 21 mmHg (P < 0.01) and NYHA class from 2.9 ± 0.5 to 1.6 ± 0.7 (P < 0.01). At the last check-up, 89% of patients reported dyspnoea of NYHA class ≤2, which was independently associated with LV outflow tract gradient (P < 0.01).

CONCLUSIONS

The Euro-ASA registry demonstrated low peri-procedural and long-term mortality after ASA. This intervention provided durable relief of symptoms and a reduction of LV outflow tract obstruction in selected and highly symptomatic patients with obstructive HCM. As the post-procedural obstruction seems to be associated with both worse functional status and prognosis, optimal therapy should be focused on the elimination of LV outflow tract gradient.