Complications of low‐dose,echo‐guided alcohol septal ablation

Background : Alcohol septal ablation (ASA) is a catheter‐based intervention that has been used as an alternative to surgical myectomy in highly symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM). Methods : This retrospective study was designed to evaluate the incidence of major complications in the mid‐term follow‐up of low‐dose (1–2.5 ml of ethanol), echo‐guided alcohol septal ablation. Results : A total of 101 consecutive patients (56 ± 15 years) with highly symptomatic HOCM were enrolled. At 6 months, there was a significant decrease in resting outflow gradient accompanied by reduction in basal septal diameter and improvement in symptoms (P < 0.01). Two patients (2%) experienced procedural ventricular tachycardias terminated by electrical cardioversion. A total of 87 patients (86%) underwent an uneventful postprocedural hospital stay. The postprocedural complete heart block occurred in 10 patients (10%), and subsequent permanent pacemaker was implanted in four cases (4%). Sustained ventricular arrhythmias requiring electrical cardioversion occurred in four patients (4%) within postprocedural hospital stay. Subsequently, ICD was not implanted in any of these cases. The patients were repeatedly examined by Holter ECG monitoring, and in the mid‐term follow‐up (6–50 months), they stayed asymptomatic and without any ventricular arrhythmias. Conclusion : This study demonstrates the same early incidence of complete heart block requiring permanent pacemaker implantation (4%) and sustained ventricular arrhythmias following low‐dose, echo‐guided ASA. © 2009 Wiley‐Liss, Inc.     

The case for surgery in obstructive hypertrophic cardiomyopathy

Relief of left ventricular (LV) outflow obstruction in patients with hypertrophic cardiomyopathy (HCM) and disabling symptoms refractory to maximum medical management has historically been a surgical problem. Surgical septal myectomy permanently abolishes systolic anterior motion of the mitral valve and mitral regurgitation, while normalizing LV pressures and wall stress. Also, these salutary goals are achieved without encumbering patients with post-procedural devices (e.g., pacemakers or defibrillators) or creating potentially arrhythmogenic substrates, as may occur with alcohol septal ablation. Procedural morbidity and mortality risk with myectomy is similar to, and in some institutions less than those for alcohol septal ablation. Over four decades, reports from numerous centers worldwide have consistently and unequivocably documented the benefits of surgery on hemodynamic and functional state, restoring normal and acceptable quality of life to patients of all ages by largely reversing the complications of heart failure. Long-term survival after myectomy is similar to that of the general population and superior to non-operated patients with obstruction. The LV outflow tract morphology in HCM is heterogeneous and not uncommonly includes congenital anomalies of the mitral valve apparatus for which the surgeon has the flexibility to adapt the repair, often employing an extended myectomy. In the current atmosphere of increasing and perhaps excessive enthusiasm for newer catheter-based interventions, it is a critical time to promote and re-emphasize that surgery is the time-honored (and presently the most effective) treatment strategy for relieving heart failure-related disability resulting from dynamic LV outflow obstruction in HCM, and is the primary treatment option for this subgroup of severely symptomatic drug-refractory patients.     

Long-term effects of varying alcohol dosing in percutaneous septal ablation for obstructive hypertrophic cardiomyopathy: a randomized study with a follow-up up to 11 years

Background

Highly symptomatic patients with obstructive hypertrophic cardiomyopathy (HCM) are candidates for alcohol septal ablation (ASA). We wanted to determine long-term (> 60 months) clinical and echocardiographic outcomes of patients treated with low (1-2 mL) or high (> 2 mL) doses of alcohol.

Methods

Seventy-six patients were randomized into 2 arms in a 1:1 ratio, and subsequently were treated by ASA with a low (1-2 mL) or high (> 2 mL) dose of alcohol. Clinical and echocardiographic examinations were performed at baseline, 1 year after the procedure, and at the end of follow-up (at least 60 months after ASA).

Results

Both groups of patients matched in all baseline clinical and echocardiographic data. In a total of 76 patients, 86 septal branches were ablated in 80 ASA procedures (2 repeat procedures in each group). There were no differences in postprocedural complications. Seven patients (4 vs 3 patients; not significant) died during follow-up (60-138 months; median 85 months). Pressure gradients decreased significantly in both groups (from 74 ± 36 to 24 ± 32 mm Hg in the low-dose group and from 74 ± 39 mm Hg to 18 ± 20 mm Hg in the high-dose group). There were no significant differences between the groups, and all main hemodynamic and echocardiographic changes occurred in the first postprocedural year. At final examination, there were no patients with New York Heart Association class > 2 dyspnea in either group.

Conclusions

This study demonstrates that ASA for obstructive hypertrophic cardiomyopathy is safe and effective in long-term follow-up. No differences in long-term efficacy and safety were found between low and high doses of alcohol.     

The Hypertrophic Cardiomyopathy Phenotype Viewed Through the Prism of Multimodality Imaging: Clinical and Etiologic Implications

Noninvasive contemporary imaging with echocardiography and cardiovascular magnetic resonance (CMR) provide comprehensive characterization of the hypertrophic cardiomyopathy (HCM) heart including precise definition of left ventricle (LV) wall thickness and reliable identification of morphologic abnormalities of the mitral valve, LV chamber, and myocardial tissue characterization with late gadolinium enhancement (LGE) (fibrosis). Imaging also contributes to identification of patients at risk for sudden death including novel high-risk features such as LV apical aneurysm and extensive LGE. Exercise (stress) echocardiography should be considered to demonstrate physiologic provocation of LV outflow gradients and to distinguish from patients with nonobstructive HCM. Multimodality imaging identifies patients who are optimal candidates for invasive septal reduction therapy and directs preoperative planning for extended myectomy and to optimize alcohol septal ablation. Contemporary imaging interwoven with current management strategies have resulted in a low HCM-related mortality rate.     

Effects of varying ethanol dosing in percutaneous septal ablation for obstructive hypertrophic cardiomyopathy on early hemodynamic changes

This prospective, randomized study evaluates the association between ethanol dose and postprocedural hemodynamic changes in 42 patients treated by alcohol septal ablation for obstructive hypertrophic cardiomyopathy. These results suggest that the early course of hemodynamic changes is not related to the use of a small (1 to 2 ml) or standard (>2 ml) dose of ethanol.     

Comparison of surgical septal myectomy and alcohol septal ablation with cardiac magnetic resonance imaging in patients with hypertrophic obstructive cardiomyopathy.

OBJECTIVES: This study sought to describe the acute morphologic differences that result from septal myectomy and alcohol septal ablation using cardiac magnetic resonance (CMR) imaging. BACKGROUND: Surgical septal myectomy and alcohol septal ablation relieve left ventricular outflow tract obstruction in severely symptomatic patients with hypertrophic cardiomyopathy (HCM). METHODS: Cine and contrast-enhanced CMR images were obtained in HCM patients before and after septal myectomy (n = 24) and alcohol septal ablation (n = 24). Location of septal reduction, extent of myocardial necrosis, and conduction system abnormalities with each technique were compared. RESULTS: With septal myectomy, there was a discrete area of resected tissue consistently localized to anterior septum. In contrast, alcohol septal ablation resulted in a more variable effect. In most patients, alcohol septal ablation caused a transmural region of tissue necrosis, located more inferiorly in the basal septum than myectomy and usually extending into the right ventricular side of the septum at the midventricular level. However, there were 6 patients after alcohol septal ablation in whom there was sparing of the basal septum with residual gradients at follow-up. After the procedure, left bundle branch block developed in 46% of septal myectomy patients, and right bundle branch block was evident in 58% of alcohol septal ablation patients. CONCLUSIONS: Septal myectomy and alcohol septal ablation for severely symptomatic, drug-refractory patients with obstructive HCM have different morphologic effects and location sites on left ventricular septal myocardium. Septal myectomy provides consistent resection of the obstructing portion of the anterior basal septum, whereas the effect of ethanol septal ablation is more variable. These findings may have important implications for patient selection and management as well as long-term outcome.     

Intervention in Hypertrophic Obstructive Cardiomyopathy

This article reviews the present status of intervention in hypertrophic obstructive cardiomyopathy. Interventions include pacing, which is best administered by VDD mode with sufficiently short atrioventricular delay as to assure ventricular capture. Occasionally, this may require the addition of atrioiventricular (AV) junctional ablation in order to achieve 100% ventricular capture. This approach alters the left ventricular (LV) contraction sequence, thereby reducing the left ventricular outflow obstruction. VVI pacing is inadequate because of the necessity for atrial contribution to the hypertrophied ventricle. This contribution may he ineffective even with VDD pacing, without the benefit of AV junctional ablation, because of late activation of the left atrium. Ablation of the left bundle branch may also achieve altered contraction sequence of the LV, but experience with this technique is very limited. Two different methods of reduction of the interventricular septum have been proposed. The first is transaortic laser, which has not gained wide acceptance, and the second is a new and promising method that appears to be less traumatic. This is alcohol delivery to the first septal branch of the left anterior descending coronary artery by an angioplasty technique. Surgical approaches include septal myomectomy directly to reduce the obstruction and mitral valve replacement to eliminate the part played in the obstruction by the anterior cusp of the valve. In conclusion, younger patients, even those who are asymptomatic, should be considered for surgical myomectomy, there being little place now for mitral valve replacement. In older patients, pacing and septal chemoablation offer the greatest promise, but their places are not yet fully established . (J Interven Cardiol 1996; 9:399–403)     

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

BackgroundAlcohol 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.MethodsFifty 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.ResultsOnly 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.ConclusionAlcohol 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.     

Transcatheter septal ablation in hypertrophic obstructive cardiomyopathy: a technical guide and review of published results

Transcatheter alcohol septal ablation (ASA) treatment of symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM) is based on the existence and degree of intraventricular obstruction. Patients with significant gradient and symptoms who do not respond to optimal medical therapy are eligible to gradient reduction through a surgical (septal myectomy) or a transcatheter (alcohol septal ablation) septal reduction. The latter encompasses occlusion of a septal branch perfusing the hypertrophied septum, which is involved in the generation of obstruction, by injecting ethanol into the supplying septal branch(es). ASA has been established as a highly effective and safe method and has outnumbered the surgical gold standard. Although the technique is straightforward, patient selection and some technical details may influence the efficacy and safety of the procedure. The technique is based on echocardiographic contrast guidance, which allows accurate target septal branch selection and optimisation of the result. Published long-term results from high-volume centres have confirmed the effectiveness of ASA and have shown excellent survival, which is comparable to that in the general population. Choice and performance of the surgical or interventional treatment should be implemented in highly specialised centres in terms of a heart-team approach, taking notice of anatomic characteristics as well as comorbidities. Involvement of all cases in international registries may reveal the individual merits and indications for the surgical and interventional treatment in HOCM.     

Twenty years of alcohol septal ablation document more than a history of a single interventional procedure

The first alcohol septal ablation (ASA) was performed in 1994. The concept of “therapeutic acute myocardial infarction” caused by application of concentrated alcohol into coronary artery is not quite unique since certain arrhythmias were treated in a similar way in the past; however, ASA has been discussed widely since its introduction and refused for many years by many cardiologists. Sufficiently robust data from long-term follow-up of patients with hypertrophic obstructive cardiomyopathy treated with ASA were obtained in the past few years only, demonstrating the safety and long-term efficacy of ASA. This article deals with a history of the above-mentioned interventional procedure, its indications, technical aspects, safety, and long-term results.     

Alcohol septal ablation for hypertrophic obstructive cardiomyopathy: a systematic review of published studies

OBJECTIVE: Alcohol septal ablation (ASA) for hypertrophic obstructive cardiomyopathy (HOCM) has emerged as a lesser invasive alternative to surgical myectomy over the past decade. The purpose of this study is to analyze all the published literature on outcomes and complications after ASA. METHODS: MEDLINE and PubMed were searched for all available published literature on ASA (June 1996-June 2005) using the terms hypertrophic obstructive cardiomyopathy (HOCM), alcohol septal ablation for hypertrophic obstructive cardiomyopathy, alcohol septal ablation for HOCM, alcohol septal ablation (ASA), transcoronary alcohol septal ablation for hypertrophic obstructive cardiomyopathy (TASH), transcoronary alcohol septal ablation for HOCM, nonsurgical septal reduction therapy (NSRT), and percutaneous transcoronary septal myocardial ablation (PTSMA). RESULTS: A total of 42 published studies (2,959 patients) were analyzed. Mean age was 53.5 (35.4-72) years with a mean male to female ratio of 1.17. Mean follow-up was 12.7 +/- 0.3 months (1.5-43.2). Absolute ethanol (3 mL) was injected in 1.2 septal perforator arteries. On average, serum CK peaked at 964 units. At 12 months, there was a sustained decrease in resting and provoked LVOT gradient (65.3-15.8 and 125.4-31.5 mmHg, respectively) accompanied by reduction in basal septal diameter (20.9-13.9 mm), improvement in NYHA Class (2.9-1.2), and increase in exercise capacity (325.3-437.5 seconds). Early mortality (within 30 days) was 1.5% (0.0-5.0%) and late mortality (beyond 30 days) was 0.5% (0.0-9.3%). Other complications include ventricular fibrillation (2.2%), LAD dissection (1.8%), complete heart block requiring permanent pacemaker (10.5%), and pericardial effusion (0.6%). A repeat ASA was performed on 6.6% of patients and 1.9% of patients underwent surgical myomectomy with resolution of symptoms. CONCLUSIONS: Literature to date suggests that ASA results in acute and intermediate-term favorable clinical and echocardiographic outcomes. A randomized controlled trial is needed to compare ASA and myomectomy in order to determine which technique provides maximal benefit.     

Left ventricular remodeling in patients with hypertrophic obstructive cardiomyopathy treated with percutaneous alcohol septal ablation: an echocardiographic study

INTRODUCTION: In patients with hypertrophic obstructive cardiomyopathy, obstruction in the left ventricular outflow tract may generate more hypertrophy. Our aim was to evaluate the impact of reducing ventricular outflow tract obstruction on left ventricular hypertrophy and remodeling after alcohol septal ablation. PATIENTS AND METHOD: 20 patients with hypertrophic obstructive cardiomyopathy who underwent alcohol septal ablation were included. Doppler echocardiography was performed in all patients at baseline, immediately after alcohol septal ablation, and at 3 and 12 months' follow-up. Left ventricular diameters and wall thickness and pressure gradients in the ventricular outflow tract were determined. RESULTS: Immediately after alcohol septal ablation, ventricular outflow tract pressure gradient decreased from 63.0 27.7 to 28.2 24.7 mmHg (p < 0.001), without significant changes in left ventricular dimensions. However, after 12 months we observed an increase in left ventricular end-diastolic (from 47.1 4.9 to 50.8 4.5 mm) and end-systolic diameter (from 27.1 3.0 to 33.7 4.6 mm), as well as a reduction in septal (from 19.5 4.0 to 15.5 2.7 mm) and posterior wall thickness (from 14.0 2.2 to 12.9 1.3 mm) (p < 0.01 in all cases). Left ventricular end-diastolic and end-systolic volumes increased (from 106.4 26.9 to 123.1 28.7 ml and from 50.2 17.3 to 56.7 18.3 ml, respectively, p < 0.01 in both cases), without changes in left ventricular ejection fraction. The reduction in ventricular outflow tract pressure gradient at 12 months' follow-up correlated significantly with the increase in left ventricular end-systolic diameter (r = 0.63; p < 0.01). CONCLUSIONS: In patients with hypertrophic obstructive cardiomyopathy who underwent alcohol septal ablation, relief of ventricular outflow tract obstruction is associated with an increase in left ventricular chamber diameters and volume. These findings suggest that middle- and long-term ventricular remodeling and regression of hypertrophy occur in these patients, which may contribute to their clinical improvement.     

Alcohol septal ablation for obstructive hypertrophic cardiomyopathy: the perfect septal branch may originate from an atypical location

Due to anatomical variability in the distribution and size of septal perforator arteries, not all patients are ideal candidates for alcohol septal ablation. Myocardial contrast echocardiography is essential in selecting the appropriate septal branch. We report a case where the target septal artery did not originate from the left anterior descending artery, but from the first diagonal branch.     

Echocardiography for Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic cardiomyopathy. The prevalence of phenotypic expression, in the absence of another systemic or cardiac disease causing increased left ventricular (LV) wall thickness, is estimated to be 1:500. The frequency of clinical presentation is far less, highlighting the need for a non-invasive diagnostic imaging tool. Echocardiography is readily available and allows for structural characterization and hemodynamic assessment of the hypertrophic heart and to screen patients at-risk for HCM, such as first degree relatives of affected individuals, and differentiate HCM from the athletic heart. Echocardiography can also be used to assess for anatomic abnormalities of the mitral valve apparatus that may exacerbate LV outflow track obstruction and to further risk stratify patients during exercise. Finally, echocardiography plays an integral role in guiding alcohol septal ablation procedures.     

Left ventricular opacification during selective intracoronary injection of echocardiographic contrast in patients with hypertrophic cardiomyopathy

Percutaneous alcohol ablation of the interventricular septum via the first septal perforator branch of the left anterior descending artery can successfully treat dynamic left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy. Increasingly, echocardiographic contrast agents are used before alcohol injection to identify the perfusion bed of the septal perforator vessels. This study describes the unexpected opacification of the left ventricular cavity in three of five consecutive patients following selective injection of the first septal perforator with Optison. This case study demonstrates that direct communication between the first septal perforator vessel and the left ventricle is common, an observation that may have considerable relevance to the technique of alcohol septal reduction.


Keywords: hypertrophic cardiomyopathy; ventricular obstruction; septal alcohol ablation     

The effects of septal myectomy and alcohol septal ablation for hypertrophic cardiomyopathy on the cardiac conduction system

AV conduction abnormalities are observed in 15–30% of patients with hypertrophic cardiomyopathy but are usually not severe enough to require permanent pacemaker implant. Both septal myectomy and alcohol septal ablation are effective options to relieve symptoms due to left ventricular outflow tract gradient in patients with hypertrophic cardiomyopathy but have procedure-specific effects on AV conduction and the His Purkinje system. Septal myectomy is associated with the development of LBBB in 50–100% of patients, while alcohol septal ablation is associated with RBBB in 37–70% of patients. Baseline abnormalities in the contralateral bundles and the presence of conduction disease have an important impact on the likelihood of the development of AV block for both of these therapies. AV block requiring permanent pacing occurs in approximately 2–3% of patients after septal myectomy and 10–15% of patients after alcohol septal ablation. Permanent pacemaker implant after alcohol septal ablation is more common in older patients (>?55 years old 13 vs. <?55 years old 5%; p?=?0.06). Improved outcomes for septal myectomy and alcohol septal ablation are observed in experienced centers. Septal reduction therapies should be performed at medical centers with a dedicated hypertrophic cardiomyopathy program using a multidisciplinary approach.     

New treatment strategies for hypertrophic obstructive cardiomyopathy: alcohol ablation of the septum: the new gold standard?

Hypertrophic cardiomyopathy is a primary myocardial disorder with an autosomal pattern of inheritance characterized by inappropriate myocardial hypertrophy. Annual mortality has been reported to be 1% to 2% and sudden death represents the most common cause. Treatment strategies are 1) medical therapy in patients with mild to moderate symptoms, 2) reduction of septal hypertrophy by surgical myectomy or alcohol ablation, and 3) implantation of an automatic cardioverter-defibrillator in the presence of non-sustained ventricular tachyarrhythmias. A debate has been started on whether surgical myectomy or alcohol ablation of the septum is the appropriate treatment for hypertrophic obstructive cardiomyopathy. Surgical (transaortic) myectomy has been the gold standard in the past 20 to 30 years for treatment of symptomatic patients with significant hemodynamic outflow tract obstruction. However, modern interventional technologies allow reduction of the myocardial septum by injection of alcohol into the first or second septal branch under guidance of two-dimensional (2D)-contrast echocardiography. This percutaneous technique not only has a lower morbidity than surgical myectomy but can be guided precisely by 2D echocardiography. One potential complication is transient (<30%) or permanent (<10%) atrioventricular block III; however, this complication is relatively rare. A randomized trial comparing the two treatment modalities is lacking, and the chance is small that such a trial will be performed because alcohol ablation can be done with high success and low complication rates, leaving only complex interventions (with valvular reconstructions and so on) for surgical myectomy.     

Quantification of Changes in Septal Strain after Alcohol Septal Ablation in Hypertrophic Obstructive Cardiomyopathy—Cases from the Three‐Dimensional Speckle Tracking Echocardiographic MAGYAR‐Path Study

Patients with hypertrophic obstructive cardiomyopathy undergoing alcohol septal ablation are presented. Three‐dimensional speckle tracking echocardiography (3DSTE) is a new, noninvasive tool for quantification of myocardial deformation. In both cases, 3DSTE was performed 1 day before and 3 days after alcohol septal ablation to quantify changes in septal strain of ablated area. Results could suggest the possible role of 3DSTE in the quantitative evaluation of the success of alcohol septal ablation.     

Cardiac resynchronization therapy by ablation of right-anterolateral accessory pathway

Ventricular preexcitation caused by right-sided accessory pathways can lead to abnormal septal motion patterns and may be associated with left ventricular (LV) dysfunction and heart failure, despite the lack of a clinical arrhythmia. Hence successful ablation of the accessory pathway abolishes not only preexcitation but also ventricular dyssynchrony in these patients. We describe a case of an asymptomatic 20-year-old male presenting with ventricular Type-B preexcitation combined with LV dysfunction. The individual risk of arrhythmic events was enhanced due to competitive sport activities of the patient and a short antegrade refractory period of the accessory pathway. Hence standard radiofrequency ablation of the right anterolateral accessory pathway was performed, despite no history of tachycardia. After successful accessory pathway ablation, normalization of LV size and function was demonstrated by echocardiography with a long-term follow-up of 4 years.     

Monomorphic ventricular tachycardia: a late complication of percutaneous alcohol septal ablation for hypertrophic cardiomyopathy

Percutaneous alcohol septal ablation has emerged as a promising treatment option for patients with symptomatic hypertrophic obstructive cardiomyopathy. Although the procedure involves an alcohol-induced myocardial infarction and results in a substrate potentially conducive to re-entrant tachyarrhythmias, late-occurring ventricular arrhythmias have not been described. We report a case of monomorphic ventricular tachycardia occurring several days after alcohol septal ablation. Patients with hypertrophic cardiomyopathy undergoing alcohol septal ablation should be considered for prophylactic placement of implantable cardioverter defibrillator.