Alcohol septal ablation for hypertrophic cardiomyopathy: Indications and technique

A Review of Pediatric Cardiomyopathy

Though pediatric cardiomyopathy is rare in children, there is significant associated morbidity and mortality. Etiology varies from inborn errors of metabolism to familial genetic mutations and myocyte injury. Major classes include dilated, hypertrophic, restrictive, and non-compaction. Diagnosis generally involves a combination of clinical history and echocardiography. The use of cross-sectional imaging is gaining popularity. Management varies between subtype and may involve a combination of medical and surgical interventions depending on clinical status.

Sex-Related Differences in Patients With Hypertrophic Cardiomyopathy Undergoing Alcohol Septal Ablation

BACKGROUND

Previous studies have shown that women with hypertrophic obstructive cardiomyopathy (HCM) have worse long-term outcomes irrespective of intervention. However, the outcomes of patients undergoing alcohol septal ablation (ASA) based on sex have not been described. Hence, this study aimed to evaluate pressure changes and long-term mortality in patients with HCM undergoing ASA based on sex.

METHODS AND RESULTS

This is a single-center retrospective study evaluating hemodynamic changes and long-term mortality in patients with HCM treated with ASA according to sex. A total of 259 patients were included (aged 68.4±11.9 years, 62.2% women). Women had higher age and baseline pressures at the time of ASA, with a greater percent reduction in mean left atrial pressure (men versus women: 2.2% versus 15.9%, respectively; P=0.02). Women had better survival (median survival rate of men versus women: 8.6 versus 12.5 years, respectively; P=0.011). On Cox multivariable regression, predictors of mortality were age (per group change <60 years, 61-70 years, 71-80 years, and >80 years; hazard ratio [HR], 1.45 [95% CI, 1.10-1.91], P=0.008), female sex (HR, 0.59 [95% CI, 0.35-0.99], P=0.048), chronic kidney disease (HR, 1.88 [95% CI, 1.06-3.33], P=0.031), and left ventricular outflow tract gradient reduction ≤86% (HR, 1.91 [95% CI, 1.14-3.19], P=0.014).

CONCLUSIONS

Women with HCM undergoing ASA are older and have higher left-sided baseline pressures compared with men yet have better survival. Further studies exploring the mechanisms of differential outcomes according to sex in patients with HCM undergoing ASA are needed.

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.

Predictors of cardiovascular implantable electronic device dependence at long-term follow-up after alcohol septal ablation in hypertrophic cardiomyopathy patients

BACKGROUND

The most common complication of alcohol septal ablation (ASA) is transient periprocedural high-grade AV block (HGAVB). To date, no long-term follow-up of cardiovascular implantable electronic device (CIED) utilization after ASA has been reported. We hypothesized that CIED dependence on long-term follow-up can be predicted by ECG or procedural characteristics.

METHODS

We analyzed all patients with HCM who underwent ASA from December 1998 to December 2019 and received their first CIED within 30 days after ASA for HGAVB. All follow-up interrogations were reviewed. CIED dependence was defined as ventricular pacing of ≥ 5%.

RESULTS

A total of 138 patients with HCM underwent ASA. Of these, 35 had a prior device and were excluded. Of the remaining 103 patients, 25 patients received a CIED for HGAVB within 30 days after ASA. Average follow-up duration was 10.1 years. On long-term follow-up, 16 patients (64%) were found to be CIED-dependent. Baseline characteristics, including pre- and post-ASA ECG, were not significantly different between dependent and non-dependent patients. The only predictor for CIED dependence was > 1 ml of alcohol injected (OR 6.0, p = 0.031).

CONCLUSIONS

CIED implantation after ASA is common. Almost two thirds of patients who received a CIED for post-procedural HGAVB were CIED-dependent on long-term follow-up. CIED dependence can be predicted by the amount of injected alcohol > 1 ml.

Hemodynamic Predictors of Outcome Following Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy

BACKGROUND

Alcohol septal ablation (ASA) is a minimally invasive treatment for drug-refractory obstructive hypertrophic cardiomyopathy. Detailed assessment of pressure changes and predictors of mortality and procedure success are not well defined.

METHODS

This is a single-center study evaluating pressure changes and predictors of mortality and procedure success in transseptal ASA. Survival analysis and predictors of mortality were assessed using the Kaplan-Meier analysis and Cox regression, respectively.

RESULTS

A total of 156 patients were included (mean age, 67.3 years; 46.8% women). Left atrial (LA) pressure and left ventricular outflow tract (LVOT) gradient decreased, whereas aortic pulse pressure (PP) increased post-ASA. Patients with lower baseline mean LA pressure (82% (gradient change median), and PP increase >19% (PP change median) had superior survival. On Cox univariable regression, baseline mean LA pressure >median (19 mm Hg; hazard ratio [HR], 2.09 [95% CI, 1.05-4.18]; P=0.036), residual LVOT gradient (HR, 1.02 [95% CI, 1.01-1.03]; P=0.003), and LVOT gradient percent reduction median (28 mm Hg; HR, 2.36 [95% CI, 1.17-4.76]; P=0.016), baseline mean LA pressure >median (19 mm Hg; HR, 2.70 [95% CI, 1.33-5.50]; P=0.006), percentage reduction in gradient

CONCLUSIONS

ASA is associated with an acute decrease in the LVOT gradient and LA pressures and increase in aortic PP. Mean LA pressure, percentage decrease in LVOT gradient, and increase in PP are strong predictors of survival free of all-cause mortality following ASA and are important variables for procedural guidance.

Collapse

Key Words

• cardiomyopathy, hypertrophic
• heart atria
• hemodynamics

Collapse

MESH Headings

• Humans
• Female
• Aged
• Male
• Treatment Outcome
• Ethanol/adverse effects
• Cardiomyopathy, Hypertrophic/diagnostic imaging
• Cardiomyopathy, Hypertrophic/surgery
• Cardiac Surgical Procedures
• Hemodynamics
• Ablation Techniques/adverse effects

Collapse

Grants Collapse

Affiliation(s)

Mohamad S. Alabdaljabar Departments of Internal Medicine (M.S.A.), Mayo Clinic, Rochester, MN
Emily E. Cendrowski Cardiovascular Medicine (E.E.C., R.A.N., W.R.M., J.B.G., C.S.R., M.F.E.), Mayo Clinic, Rochester, MN
Rick A. Nishimura Cardiovascular Medicine (E.E.C., R.A.N., W.R.M., J.B.G., C.S.R., M.F.E.), Mayo Clinic, Rochester, MN
William R. Miranda Cardiovascular Medicine (E.E.C., R.A.N., W.R.M., J.B.G., C.S.R., M.F.E.), Mayo Clinic, Rochester, MN
Jeffrey B. Geske Cardiovascular Medicine (E.E.C., R.A.N., W.R.M., J.B.G., C.S.R., M.F.E.), Mayo Clinic, Rochester, MN
Charanjit S. Rihal Cardiovascular Medicine (E.E.C., R.A.N., W.R.M., J.B.G., C.S.R., M.F.E.), Mayo Clinic, Rochester, MN
Mackram F. Eleid Cardiovascular Medicine (E.E.C., R.A.N., W.R.M., J.B.G., C.S.R., M.F.E.), Mayo Clinic, Rochester, MN

Collapse

Alcohol Septal Ablation in Patients with Hypertrophic Obstructive Cardiomyopathy: A Contemporary Perspective

Alcohol septal ablation is a minimally invasive procedure for the treatment of left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic obstructive cardiomyopathy (HOCM) who remain symptomatic despite optimal medical therapy. The procedure causes a controlled myocardial infarction of the basal portion of the interventricular septum by the injection of absolute alcohol with the aim of reducing LVOT obstruction and improving the patient's hemodynamics and symptoms. Numerous observations have demonstrated the efficacy and safety of the procedure, making it a valid alternative to surgical myectomy. In particular, the success of alcohol septal ablation depends on appropriate patient selection and the experience of the institution where the procedure is performed. In this review, we summarize the current evidence on alcohol septal ablation and highlight the importance of a multidisciplinary approach involving a team of clinical and interventional cardiologists and cardiac surgeons with high expertise in the management of HOCM patients-the Cardiomyopathy Team.

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.

Safety and Outcomes of Alcohol Septal Ablation Prior to Transcatheter Mitral Valve Replacement

Background

Patients undergoing transcatheter mitral valve replacement (TMVR) for mitral valve disease caused by severe mitral annular calcification are at risk of left ventricular outflow obstruction. Preemptive alcohol septal ablation (ASA) can potentially mitigate the risk of this complication and is well established in patients with hypertrophic obstructive cardiomyopathy (HCM).

Methods

This retrospective study compared procedural characteristics and outcomes in patients who underwent ASA for TMVR vs HCM.

Results

In total, 102 patients were included, 22 in the TMVR group and 80 in the HCM group. Echocardiography demonstrated increased septal wall thickness in the HCM group (19 ​± ​3.1 ​mm vs 12.7 ​± ​2.0 ​mm; P ​< ​.001). The mean volume of ethanol injected was higher in the HCM group (1.4 ​± ​0.49 ​mL vs 0.8 ​± ​0.2 ​mL; P ​< ​.001). The average neo-left ventricular outflow tract area increased significantly after ASA in the patients undergoing TMVR (135 ​± ​89 ​mm2 vs 233 ​± ​111 ​mm2; P ​< ​.001). Six patients in the TMVR group did not achieve an adequate increase in the neo-left ventricular outflow tract area and required further procedures after ASA. The incidence of post-ASA complete heart block requiring a permanent pacemaker tended to be higher in the TMVR group (35% vs 21%; P ​= ​.195). No patients in either group had ventricular arrhythmia or stroke. Major bleeding complications were 4% in the HCM group and 0 in the TMVR group. The 30-day mortality was 4% in the HCM group and 0 in the TMVR group; however, 1 patient died at 37 ​days in the TMVR group, presumably from late heart block.

Conclusions

Preemptive ASA in patients undergoing TMVR demonstrated safety and short-term clinical outcomes similar to patients with HCM.

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.

Inadvertent Septal Ablation During Percutaneous Coronary Intervention

We present a case of inadvertent occlusion of a septal artery from being jailed during percutaneous coronary intervention of left anterior descending artery. This resulted in partial loss of the interventricular septum. Risks of side branch occlusion and bifurcation stenting are discussed.

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.

Ablation Modalities for Therapeutic Intervention in Arrhythmia-Related Cardiovascular Disease: Focus on Electroporation

Targeted cellular ablation is being increasingly used in the treatment of arrhythmias and structural heart disease. Catheter-based ablation for atrial fibrillation (AF) is considered a safe and effective approach for patients who are medication refractory. Electroporation (EPo) employs electrical energy to disrupt cell membranes which has a minimally thermal effect. The nanopores that arise from EPo can be temporary or permanent. Reversible electroporation is transitory in nature and cell viability is maintained, whereas irreversible electroporation causes permanent pore formation, leading to loss of cellular homeostasis and cell death. Several studies report that EPo displays a degree of specificity in terms of the lethal threshold required to induce cell death in different tissues. However, significantly more research is required to scope the profile of EPo thresholds for specific cell types within complex tissues. Irreversible electroporation (IRE) as an ablative approach appears to overcome the significant negative effects associated with thermal based techniques, particularly collateral damage to surrounding structures. With further fine-tuning of parameters and longer and larger clinical trials, EPo may lead the way of adapting a safer and efficient ablation modality for the treatment of persistent AF.

Alcohol Septal Ablation: An Option on the Rise in Hypertrophic Obstructive Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) can cause symptoms due to the obstruction of the left ventricle outflow tract (LVOT). Although pharmacological therapy is the first step for treating this condition, many patients do not fully respond to the treatment, and an invasive approach is required to manage symptoms. Septal reduction therapies include septal myectomy (SM) and alcohol septal ablation (ASA). ASA consists of a selective infusion of high-grade alcohol into a septal branch supplying the basal interventricular septum to create an iatrogenic infarction with the aim of reducing LVOT obstruction. Currently, SM and ASA have the same level of indication; however, ASA is normally reserved for patients of advanced age, with comorbidities or when the surgical approach is not feasible. Recent data suggests that there are no differences in short- and long-term all-cause mortality, cardiovascular mortality and sudden cardiac death between ASA and SM. Despite the greater experience and refinement of the technique gained in recent years, the most common complication continues to be complete atrio-ventricular block, requiring a permanent pacemaker. Septal reduction therapies should be performed in experienced centres with comprehensive programs.

Recognition of acute myocardial infarction caused by spontaneous coronary artery dissection of first septal perforator

AIMS 

Spontaneous coronary artery dissection (SCAD) diagnosis is challenging as angiographic findings are often subtle and differ from coronary atherosclerosis. Herein, we describe characteristics of patients with acute myocardial infarction (MI) caused by first septal perforator (S1) SCAD.

METHODS AND RESULTS 

Patients were gathered from SCAD registries at Minneapolis Heart Institute and Vancouver General Hospital. First septal perforator SCAD prevalence was 11 of 1490 (0.7%). Among 11 patients, age range was 38-64 years, 9 (82%) were female. Each presented with acute chest pain, troponin elevation, and non-ST-elevation MI diagnosis. Initial electrocardiogram demonstrated ischaemia in 5 (45%); septal wall motion abnormality was present in 4 (36%). Angiographic type 2 SCAD was present in 7 (64%) patients with S1 TIMI 3 flow in 7 (64%) and TIMI 0 flow in 2 (18%). Initial angiographic interpretation failed to recognize S1-SCAD in 6 (55%) patients (no culprit, n = 5, septal embolism, n = 1). First septal perforator SCAD diagnosis was established by review of initial coronary angiogram consequent to cardiovascular magnetic resonance (CMR) demonstrating focal septal late gadolinium enhancement with corresponding oedema (n = 3), occurrence of subsequent SCAD event (n = 2), or second angiogram showing healed S1-SCAD (n = 1). Patients were treated conservatively, each with ejection fraction >50%.

CONCLUSION 

First septal perforator SCAD events may be overlooked at initial angiography and mis-diagnosed as 'no culprit' MI. First septal perforator SCAD prevalence is likely greater than reported herein and dependent on local expertise and availability of CMR imaging. Spontaneous coronary artery dissection events may occur in intra-myocardial coronary arteries, approaching the resolution limits of invasive coronary angiography.

Looking back on 15 years of ultrasound-guided alcohol septal ablation for hypertrophic obstructive cardiomyopathy

Background: Septal reduction remains an important target of current therapeutic modalities in hypertrophic obstructive cardiomyopathy (HOCM). Surgical septal myectomy has long been considered the gold standard in pharmacotherapy-refractory severely symptomatic patients with marked left ventricular outflow tract (LVOT) obstruction. In recent years, percutaneous alcohol septal ablation (ASA) has matured into the preferred strategy for patients with favourable anatomy and no other coexisting surgically amenable disease.Methods: We discuss 26 HOCM patients with persistent dyspnoea, angina or syncope despite optimal medical treatment. Baseline septal wall thickness was 20 ± 3 mm, with peak resting/provoked LVOT gradients of 53 ± 35/112 ± 40 mmHg. Guided by echocardiography, alcohol injection could be restricted to the first septal coronary artery in 85% of patients, provoking basal septal infarction with average troponin rise of 3.0 ng/ml.Results: Eighty-six per cent of patients experienced sustained clinical improvement, associated with a reduction of septal wall thickness to 15 ± 3 mm and resting LVOT gradient to 21 ± 15 mmHg. One of the two non-responders underwent additional septal myectomy 11 years after ASA. Notable adverse events during the follow-up of 7.2 ± 4.7 years included: persistent conduction disturbances (65%) necessitating early postprocedural permanent pacemaker implantation (15%); atrial fibrillation (32%); ventricular tachycardia (4%) and aortic stenosis (14%). Six patients died, of which only 1 cardiac death.Conclusions: Our case series underscores the efficacy of ASA at relieving LVOT obstruction and improving symptoms in properly selected HOCM patients, with acceptably low procedural and long term mortality and morbidity.

Alcohol septal ablation in patients with concomitant hypertrophic cardiomyopathy and aortic valvular stenosis

OBJECTIVE

To describe the hemodynamic and early clinical outcomes of percutaneous alcohol septal ablation in patients with concomitant dynamic left ventricular outflow tract (LVOT) obstruction and aortic valvular stenosis (AS).

BACKGROUND

Alcohol septal ablation is an established method to relieve dynamic LVOT obstruction in patients with hypertrophic cardiomyopathy (HCM). However, the feasibility, safety, and efficacy of alcohol septal ablation in patients with serial obstructions from HCM and AS remain unclear.

METHODS

In this case series, we describe the early outcomes of alcohol septal ablation in six patients with significant dynamic LVOT obstruction and AS. All patients had evidence of severe dynamic LVOT obstruction (resting or provoked gradient ≥50 mmHg), mild to severe AS, and NYHA class III symptoms or greater.

RESULTS

Four (66.7%) patients had septal ablation performed in the setting of concomitant native valvular AS and two (33.3%) patients had TAVR performed prior to septal ablation. Successful alcohol septal ablation was performed in all patients and was associated with an immediate reduction of the dynamic LVOT gradient with a residual fixed obstruction related to AS. Four (66.7%) patients had follow-up at 1 month and of these, three (75%) had NYHA Class I-II symptoms and one (25%) Class III.

CONCLUSIONS

Alcohol septal ablation is a feasible method of relieving dynamic LVOT obstruction in patients with concomitant HCM and AS. Further study is required to determine the optimal treatment approach in these patients.

Temporal Occurrence of Arrhythmic Complications After Alcohol Septal Ablation

BACKGROUND

The temporal occurrence of arrhythmic complications after alcohol septal ablation (ASA) is unclear. As a result, the appropriate time to monitor patients after ASA is controversial. The purpose of this study is to determine the temporal occurrence of complete heart block (CHB) and ventricular tachyarrhythmia (VT) after ASA to better understand when patients can be safely discharged.

METHODS

Consecutive patients treated with ASA for hypertrophic cardiomyopathy from 2003 to 2019 at a tertiary referral center were reviewed retrospectively. The incidence and timing of CHB or sustained VT within 30 days post-ASA were assessed.

RESULTS

A total of 243 patients were included in this study. Mean maximal septal thickness was 19.0±3.9 mm, and total volume of ethanol injected was 1.7±0.6 mL. CHB occurred in 59 (24.3%) patients, including transient CHB in 33 (13.6%) and permanent in 26 (10.7%). The initial episode of CHB occurred within 24 hours post-ASA in 51 (21.0%) patients, between 24 and 48 hours in 3 (1.2%), between 48 and 72 hours in 3 (1.2%), and after 72 hours in 2 (0.8%). New permanent pacemaker was placed in 46 (18.3%). Presence of baseline bundle branch block and age ≥70 were significantly associated with CHB but not CHB presenting after 24 hours. VT occurred in 3 (1.2%) patients, including 1 (0.4%) within 24 hours, 1 (0.4%) between 24 and 48 hours, and 1 (0.4%) after 72 hours. VT required cardioversion in 2 patients and new implantable cardioverter-defibrillator placement in 2.

CONCLUSIONS

The incidence of CHB or VT presenting after 72 hours post-ASA was low. These findings suggest that timely discharge of patients without evidence of early conduction disturbances after ASA can be considered as a potentially safe management strategy, especially in patients without preexisting conduction abnormalities.

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.

Short- and long-term outcome after alcohol septal ablation in obstructive hypertrophic cardiomyopathy: Experience of a reference center

INTRODUCTION

In obstructive hypertrophic cardiomyopathy (HCM), alcohol septal ablation (ASA) can lead to gradient reduction and symptom improvement. We aimed to assess the efficacy and safety of ASA in a long-term outcome study.

METHODS

We analyzed patients who underwent ASA over a seven-year period in a tertiary center. The primary echocardiographic endpoint was >50% reduction in left ventricular outflow tract (LVOT) gradient within a year of the procedure. The primary clinical endpoints were improvement in functional capacity and a combined endpoint of cardiac death and rehospitalization for cardiac cause. The follow-up period was 4.17±2.13 years.

RESULTS

A total of 80 patients, mean age 63.9±12.3 years, 30.0% male, were analyzed. Baseline LVOT gradient was 96.3±34.6 mmHg and interventricular septal thickness was 21.6±3.1 mm. Minor complications were observed in 6.3% and major complications in 2.5%, and 8.8% received a permanent pacemaker. The primary echocardiographic endpoint was achieved by 85.7%. At three-month follow-up, LVOT gradient was 25.8±26.0 mmHg in the successful procedure group, compared to 69.2±35.6 mmHg in the other patients (p=0.001). At six months, LVOT gradient was 27.1±27.4 vs. 58.2±16.6 mmHg (p=0.024). Among 74 patients in NYHA class III/IV before the procedure, 57 (77%) improved to NHYA class I/II. The combined primary clinical endpoint (cardiac death and rehospitalization for cardiac cause) was observed in 27.5% (n=22). In the unsuccessful group, the combined endpoint was observed in 54.5%, compared to only 22.7% in the successful group. Only two patients died of cardiac causes.

CONCLUSION

ASA is a safe procedure with a high success rate. Patients who achieved significant reductions in LVOT gradient suffered less cardiac death and rehospitalization for cardiac cause.

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.

Layer-specific strain analysis of left ventricular myocardium after alcohol septal ablation for hypertrophic obstructive cardiomyopathy

INTRODUCTION

We aimed to explore the layer-specific systolic strain of left ventricular (LV) myocardium in patients with hypertrophic obstructive cardiomyopathy (HOCM) before and after alcohol septal ablation (ASA).The routine 2D (frame rate: >50 Hz) data sets were acquired using GE Vivi7 system for 44 consecutive HOCM patients and 21 matched normal subjects. Fifteen of HOCM patients had serial echocardiograms available for speckle tracking analyses before and 1 year after ASA. 2D strain was analyzed by EchoPAC software.The layer strain from inner to mid-myocardial and outer layers in basal and middle segments in HOCM patients continuously declined. The absolute values of peak systolic strains from the endocardium to mid-myocardium and epicardium in the basal septum of the HOCM group were significantly lower than those of the normal group (P <.01). Meanwhile, the layer systolic strain of LV endocardium in the basal septum increased significantly during a 1-year follow-up (P <.05).

CONCLUSIONS

The layer-specific strains of HOCM patients measured by tissue Doppler echocardiography decreased significantly compared to those of normal individuals. The increased specific layer strain of LV endocardium in the basal septum may be a valid marker of echocardiographic improvement in HOCM patients receiving ASA.

Septal reduction therapy using nonalcohol agent in hypertrophic obstructive cardiomyopathy: Single center experience

AIMS

Percutaneous septal reduction therapy by either alcohol or nonalcohol agents is an alternative approach to surgery in drug-refractory symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM). Nonalcohol agents have some advantages and disadvantages over alcohol during the procedure. Nowadays, a novel non-alcohol agent, named as Ethylene-vinyl alcohol (EVOH) copolymer (Onyx^® and Squid^® ), is used during septal ablation. Thus, in this study, we aimed to evaluate both acute and long-term efficacy and safety profile of EVOH during septal ablation in HOCM.

METHODS AND RESULTS

A total of 25 patients (52% female; mean age: 55.8 ± 17.1 years) with symptomatic HOCM were enrolled in the study. All subjects underwent clinical and laboratory assessment before and after the procedure. Peak left ventricular outflow tract (LVOT) gradient was significantly reduced just after the procedure (68 vs. 20 mmHg; P < 0.001). Peak serum creatine kinase-myocardial band and troponin I levels were 112 (35-282) ng/ml and 11 (4-93) ng/ml. EVOH embolization to diagonal artery was observed in 1 patient (4%) and the complete atrioventricular block was noted in 2 (8%) patients. During the 12-month follow-up, there was no mortality. There was a significant improvement in New York Heart Association functional class of the subjects P < 0.001). Both interventricular septum thickness and LVOT gradient showed a significant reduction during follow-up (P < 0.05). However, there was no reduction in the LVOT gradient of 3 patients (12%).

CONCLUSIONS

In conclusion, our small-sized preliminary study results showed that septal reduction therapy using EVOH is an effective alternative option in reducing symptoms and LVOT gradient in HOCM.

Alcohol septal ablation for hypertrophic obstructive cardiomyopathy in a patient with a chronic total occlusion of the right coronary artery: "beware of collateral damage"

Alcohol septal ablation (ASA) is an effective semi-invasive alternative to surgical myectomy in selected patients for the management of severely symptomatic and drug-refractory hypertrophic obstructive cardiomyopathy (HOCM). One contraindication of this procedure is the presence of collateral flow originating from the target septal perforator to a remote myocardial territory. In such circumstances, ethanol injection could cause remote non-target myocardial necrosis in the collateralized territory. Percutaneous revascularization of the collateralized vessel prior to ASA might cope with this contraindication by restoring normal antegrade flow in the occluded artery. We report a case that illustrates the feasibility and efficacy of such strategy.

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.

Glue septal ablation: A promising alternative to alcohol septal ablation

Hypertrophic cardiomyopathy (HCM) is defined as myocardial hypertrophy in the absence of another cardiac or systemic disease capable of producing the magnitude of present hypertrophy. In about 70% of patients with HCM, there is left ventricular outflow tract (LVOT) obstruction (LVOTO) and this is known as obstructive type of hypertrophic cardiomyopathy (HOCM). Cases refractory to medical treatment have had two options either surgical septal myectomy or alcohol septal ablation (ASA) to alleviate LVOT gradient. ASA may cause some life-threatening complications including conduction disturbances and complete heart block, hemodynamic compromise, ventricular arrhythmias, distant and massive myocardial necrosis. Glue septal ablation (GSA) is a promising technique for the treatment of HOCM. Glue seems to be superior to alcohol due to some intrinsic advantageous properties of glue such as immediate polymerization which prevents the leak into the left anterior descending coronary artery and it is particularly useful in patients with collaterals to the right coronary artery in whom alcohol ablation is contraindicated. In our experience, GSA is effective and also a safe technique without significant complications. GSA decreases LVOT gradient immediately after the procedure and this reduction persists during 12 months of follow-up. It improves New York Heart Association functional capacity and decrease interventricular septal wall thickness. Further studies are needed in order to assess the long-term efficacy and safety of this technique.

Current status and future perspectives on alcohol septal ablation for hypertrophic obstructive cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiac disease. Patients may present with a wide variety of symptoms, ranging from relatively asymptomatic to heart failure, recurrent syncope, angina, or sudden death. Once diagnosed, a thorough clinical, anatomic and physiologic assessment should be undertaken. Treatment options include both pharmacologic and invasive therapies, with a goal to reduce symptoms and possibly extend longevity. Traditionally, the "gold standard" for treating severe obstructive HCM has been ventricular septal myotomy-myomectomy. Since its introduction in 1994, alcohol septal ablation (ASA) has emerged as an acceptable alternative in patients who meet strict anatomic criteria, and has been supported in recent guidelines. We review the indications, technique, competency requirements, alternatives, outcomes, complications, and future directions of ASA.

Left ventricular systolic function following alcohol septal ablation for symptomatic hypertrophic cardiomyopathy

Because alcohol septal ablation (ASA) for the treatment of symptomatic hypertrophic cardiomyopathy (HC) with left ventricular (LV) outflow tract (LVOT) obstruction results in a myocardial infarct of up to 10% of ventricular mass, LV systolic function could decline over time. We evaluated LV function during longitudinal follow-up in a cohort of patients who underwent ASA. We studied 145 consecutive patients with HC that underwent 167 ASA procedures from 2002 to 2011. Echocardiographic follow-up was available in 139 patients (96%). Echocardiographic indexes included LV ejection fraction (LVEF), mitral regurgitation severity, systolic anterior motion of the anterior mitral leaflet, and resting and provoked LVOT gradients. All patients had a baseline LVEF of >55%. LVEF was preserved in 97.1% of patients over a mean follow-up time of 3.1±2.3 years (maximum 9.7). Mild LV systolic dysfunction was observed (LVEF range 44% to 54%) in only 4 patients. Mitral regurgitation severity improved in 67% (n=112 of 138 with complete data). Resting LVOT gradient declined from a mean of 75 to 19 mm Hg (p<0.001), and provoked gradient declined from a mean of 101 to 33 mm Hg (p<0.001). New York Heart Association class improved from a mean of 2.9±0.4 to 1.3±0.5 (p<0.001). In conclusion, LV systolic function is only mildly reduced in a minority of patients after ASA for symptomatic HC; other echocardiographic and functional measures were significantly improved.

Alcohol septal ablation for hypertrophic obstructive cardiomyopathy - 8 years follow up

Background

Alcohol septal ablation is emerging as an alternative to surgical myectomy in the management of symptomatic cases of Hypertrophic obstructive cardiomyopathy (HOCM). This involves injection of absolute alcohol into 1st septal perforator thereby producing myocardial necrosis with resultant septal remodelling within 3–6 months. This results in reduction of septal thickness and LV outflow gradients with improvement in symptoms.

Methods

Fifty three patients had undergone alcohol septal ablation, there were 2 early and 2 late deaths and 4 patients lost to follow up. Forty-five (85%) of them were followed up to a mean period of 96 ± 9.2 months. Clinical, ECG, and Echocardiographic parameters were evaluated during follow up.

Results

Only 4 out of 51 patients remained in NYHA class III or IV at the end of 6 months. Significant reduction of LV outflow gradients (79 ± 35 to 34 ± 23 mmHg) and septal thickness (23 ± 4.7 mm to 19 ± 3 mm) were observed during 6 months follow up. Beyond 6 months there was no further decrease in either septal thickness or LVOT gradients noted. Ten percent of patients needed pacemaker implantation. There was 92% survival at the end of 8 years.

Conclusion

Alcohol septal ablation is a safe and effective nonsurgical procedure for the treatment of HOCM. By minimizing the amount of alcohol to ≤2 ml, one can reduce complications and mortality. The long-term survival is gratifying.

Survival After Alcohol Septal Ablation for Obstructive Hypertrophic Cardiomyopathy

Background—

The clinical efficacy of alcohol septal ablation for obstructive hypertrophic cardiomyopathy (HCM) has been demonstrated, but the long-term effects of the procedure remain uncertain. This study examined the survival of patients after septal ablation performed in a tertiary HCM referral center.

Methods and Results—

We examined 177 patients (mean age, 64 years; 68% women) who underwent septal ablation at our institution. Over a follow-up of 5.7 years, survival free of all mortality was no different than the expected survival for a comparable general population, and similar to that of age- and sex-matched patients who underwent isolated surgical myectomy (8-year survival estimate, 79% versus 79%; P =0.64). For the end point of documented sudden cardiac death or unknown cause of death, the incidence per 100 person-year follow-up was 1.31 (95% confidence interval, 0.60–2.38). Residual left ventricular outflow tract gradient after ablation was an independent predictor of long-term survival free of any death.

Conclusions—

In this nonrandomized study of carefully selected patients undergoing septal ablation by experienced operators in a tertiary referral HCM center, long-term survival was favorable and similar to that of an age- and sex-matched general population, and to patients undergoing surgical myectomy, as well, without an increased risk of sudden cardiac death.

Predictors of an optimal clinical outcome with alcohol septal ablation for obstructive hypertrophic cardiomyopathy

BACKGROUND

Alcohol septal ablation has emerged as a therapy for patients with obstructive hypertrophic cardiomyopathy (HCM). However, there are limited data on the predictors of success with the procedure.

METHODS

We examined patient characteristics and cardiac morphology as well as procedural data on 166 HCM patients (mean age, 63 years; 43% men), who underwent ablation at Mayo Clinic. Patients were contacted to determine vital status and symptoms to assess the primary endpoint of survival free of death and severe symptoms (New York Heart Association, class III or IV dyspnea).

RESULTS

The strongest patient characteristics that predicted clinical success were older age, less severe left ventricular outflow tract gradient, lesser ventricular septal hypertrophy, and a smaller left anterior descending (LAD) diameter. Mitral valve geometry or ventricular septal morphology did not predict outcome. Patients with ≥3 characteristics (age ≥65 years, gradient <100 mmHg, septal hypertrophy ≤18 mm, LAD diameter <4.0 mm) had superior 4-year survival free of death and severe symptoms (90.4%) in comparison to those with two characteristics (81.6%) and ≤1 characteristic (57.5%). Case volume with >50 patients was an independent predictor of survival free of severe symptoms. The volume of alcohol injected, number of arteries injected, or size of septal perforator artery were not predictive of clinical success.

CONCLUSIONS

Greater case volume and selection for key patient and anatomic characteristics are associated with superior outcomes with alcohol septal ablation.

Alcohol septal ablation for hypertrophic obstructive cardiomyopathy

Since its original description in 1994, alcohol septal ablation (ASA) has emerged as a minimally invasive modality for treatment of hypertrophic obstructive cardiomyopathy compared to surgical myomectomy. This catheter-based intervention relies on the injection of absolute alcohol into the septal perforator to induce a controlled infarction of the hypertrophied septum and consequently abolish the dynamic outflow obstruction. This gradient reduction has been correlated with a significant clinical improvement in the patient’s symptomatology and with left ventricular remodeling. The procedure has been refined throughout the years, especially with the introduction of myocardial contrast echocardiography for localization of the area at risk of infarction and the reduction in the amount of alcohol used. Major complications of ASA are uncommon in large referral centers but conduction system disturbances has been the most commonly reported complications of ASA with 10% of patients necessitating permanent pacemaker implantation for complete heart block. ASA has not been compared to the gold standard surgical myomectomy in a randomized prospective study. We review the clinical aspects of this procedure and provide some historical background.

Controversies in cardiovascular medicine. Hypertrophic obstructive cardiomyopathy: alcohol septal ablation

Alcohol septal ablation (ASA) was introduced in 1994 as an alternative to septal myectomy for patients with hypertrophic obstructive cardiomyopathy and symptoms refractory to medical therapy. This procedure alleviates symptoms by producing a targeted, limited infarction of the upper interventricular septum, resulting in an increase in left ventricular outflow tract (LVOT) diameter, a decrease in LVOT gradient, and regression of the component of LV hypertrophy that is due to pressure overload. Clinical success, with improvement in symptoms and reduction in gradient, is achieved in the great majority of patients with either resting or provocable LVOT obstruction. The principal morbidity of the procedure is complete heart block, resulting in some patients in the requirement for a permanent pacemaker. The introduction of myocardial contrast echocardiography as a component of the ASA procedure has contributed to the induction of smaller myocardial infarctions with lower dosages of alcohol and, in turn, fewer complications. Non-randomized comparisons of septal ablation and septal myectomy have shown similar mortality rates and post-procedure New York Heart Association class for the two procedures.