Transcoronary ablation of septal hypertrophy (TASH): a new treatment option for hypertrophic obstructive cardiomyopathy

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.

Pacing for drug-refractory or drug-intolerant hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a genetic disease with an autosomal-dominant inheritance for which negative inotropes are the most widely used initial therapies. Observational studies and small randomised trials have suggested symptomatic and functional benefits using pacing and several theories have been put forward to explain why. Pacing, although not the primary treatment for HCM, could be beneficial to patients with relative or absolute contraindications to surgery or alcohol ablation. Several randomised controlled trials comparing pacing to other therapeutic modalities have been conducted but no Cochrane-style systematic review has been done.

OBJECTIVES

To assess the effects of pacing in drug-refractory or drug-intolerant hypertrophic cardiomyopathy patients.

SEARCH METHODS

We searched the following on the 14/4/2010: CENTRAL (The Cochrane Library 2010, Issue 1), MEDLINE OVID (from 1950 onwards ), EMBASE OVID (from 1980 onwards ), Web of Science with Conference Proceedings (from 1970 onwards). No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials of either parallel or crossover design that assess the beneficial and harmful effects of pacing for hypertrophic cardiomyopathy were included. When crossover studies were identified, we considered data only from the first phase.

DATA COLLECTION AND ANALYSIS

Data from included studies were extracted onto a pre-formed data extraction paper by two authors independently. Data was then entered into Review Manager 5.1 for analysis. Risk of bias was assessed using the guidance provided in the Cochrane Handbook. For dichotomous data, relative risk was calculated; and for continuous data, the mean differences were calculated. Where appropriate data were available, meta-analysis was performed. Where meta-analysis was not possible, a narrative synthesis was written. A QUROUM flow chart was provided to show the flow of papers.

MAIN RESULTS

Five studies (reported in 10 papers) were identified. However, three of the five studies provided un-usable data. Thus the data from only two studies (reported in seven papers) with 105 participants were included for this review. There was insufficient data to compare results on all-cause mortality, cost effectiveness, exercise capacity, Quality of life and Peak O2 consumption.When comparing active pacing versus placebo pacing on exercise capacity, one study showed that exercise time decreased from (13.1 ± 4.4) minutes to (12.6 ± 4.3) minutes in the placebo group and increased from (12.1 ± 5.6) minutes to (12.9 ± 4.2) minutes in the treatment group (MD 0.30; 95% CI -1.54 to 2.14). Statistically significant data from the same study showed that left ventricular outflow tract obstruction decreased from (71 ± 32) mm Hg to (52 ± 34) mm Hg in the placebo group and from (70 ± 24) mm Hg to (33 ± 27) mm Hg in the active pacing group (MD -19.00; 95% CI -32.29 to -5.71). This study was also able to show that New York Heart Association (NYHA) functional class decreased from (2.5 ± 0.5) to (2.2 ± 0.6) in the inactive pacing group and decreased from (2.6 ± 0.5) to (1.7 ± 0.7) in the placebo group (MD -0.50; 95% CI -0.78 to -0.22).When comparing active pacing versus trancoronary ablation of septal hypertrophy (TASH), data from one study showed that NYHA functional class decreased from (3.2 ± 0.7) to (1.5 ± 0.5) in the TASH group and decreased from (3.0 ± 0.1) to (1.9 ± 0.6) in the pacemaker group. This study also showed that LV wall thickness remained unchanged in the active pacing group compared to reduction from (22 ± 4) mm to (17 ± 3) mm in the TASH group (MD 0.60; 95% CI -5.65 to 6.85) and that LV outflow tract obstruction decreased from (80 ± 35.5) mm Hg in the TASH group to (49.3 ± 37.7) mm Hg in the pacemaker group.

AUTHORS' CONCLUSIONS

Trials published to date lack information on clinically relevant end-points. Existing data is derived from small trials at high risk of bias, which concentrate on physiological measures. Their results are inconclusive. Further large and high quality trials with more appropriate outcomes are warranted.

A decade of percutaneous septal ablation in hypertrophic cardiomyopathy

Percutaneous septal ablation has emerged as a less invasive treatment of symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM). In the past decade, the availability of this sophisticated technique has revived the interest of cardiologists in left ventricular outflow tract obstruction, which led to the recognition that most patients with HCM have the obstructive type. Follow-up studies have already shown the safety and efficacy of the procedure, which offers symptomatic relief in most patients. Long-term survival is comparable to historical reports after surgical myectomy. Complications are rare and can be further reduced with increased experience of the operators, and the theoretical concern for possible ventricular arrhythmogenicity of the myocardial scar has not been documented by the existing data. Although there are still no randomized trials, percutaneous septal ablation is undeniably a viable alternative for patients with HOCM.

Visualization of transcoronary ablation of septal hypertrophy in patients with hypertrophic obstructive cardiomyopathy: a comparison between cardiac MRI, invasive measurements and echocardiography

Objective

Hypertrophic obstructive cardiomyopathy (HOCM) is treated by surgical myectomy or transcoronary ablation of septal hypertrophy (TASH). The aim of this study was to visualize the feasibility, success and short-term results of TASH on the basis of cardiac MRI (CMR) in comparison with cardiac catheterization and echocardiography.

Methods

In this in vivo study, nine patients with HOCM were treated with TASH. Patients were evaluated by transthoracic echocardiography, invasive cardiac angiography and CMR. Follow-up examinations were carried out after 1, 3 and 12 months. MR imaging was performed on a 1.5-T scanner. All images were processed using the semiautomatic Argus software and were evaluated by an attending thoracic radiologist and cardiologist.

Results

The echocardiographic pressure gradient (at rest) was 69.3 ± 15.3 mmHg before and 22.1 ± 5.7 mmHg after TASH (P < 0.01, n = 9). The flux acceleration over the aortic valve examined (V_max) was 5.1 ± 0.6 m/s before and 3.4 ± 0.3 m/s after the TASH procedure (P < 0.05). Also, there was a decrease of septum thickness from 22.0 ± 1.2 to 20.2 ± 1.0 mm (P < 0.05) after 6 ± 3 weeks. The invasively assessed pressure gradient at rest was reduced from 63.7 ± 15.2 to 21.2 ± 11.1 mmHg (P < 0.01) and the post-extrasystolic gradient was reduced from 138.9 ± 12.7 to 45.6 ± 16.5 mmHg (P < 0.01). All differences as well as the quantity of injected ethanol were plotted against the size or amount of scar tissue as assessed in the MRI. There was a statistically significant correlation between the post-extrasystolic gradient decrease and the amount of scar tissue (P = 0.03, r² = 0.5). In addition, the correlation between the quantity of ethanol and scar tissue area was highly significant (P < 0.01, r² = 0.6), whereas the values for the gradient deviation (P = 0.10, r² = 0.34), ΔV_max (P = 0.12, r² = 0.31), as well as the gradient at rest (P = 0.27, r² = 0.17) were not significant.

Conclusion

TASH was consistently effective in reducing the gradient in all patients with HOCM. In contrast to the variables investigated by echocardiography, the invasively measured post-extrasystolic gradient correlated much better with the amount of scar tissue as assessed by CMR. We conclude that the optimal modality to visualize the TASH effect seems to be a combination of CMR and the invasive identification of the post-extrasystolic gradient.

Sudden cardiac death complicating alcohol septal ablation: a case report and review of literature

Over the years, alcohol septal ablation has become an effective and well-accepted modality in the treatment of patients with hypertrophic obstructive cardiomyopathy refractory to standard medical therapy. Malignant tachyarrythmias infrequently complicates the procedure and are usually self-terminating. We describe a case of alcohol septal ablation complicated by sudden cardiac death occurring immediately following the procedure requiring prolonged resuscitative efforts with eventual complete recovery. We also discuss the pathophysiologic significance of this event in the setting of this cardiomyopathy and its relevance as a complication of the procedure.

Percutaneous transluminal septal myocardial ablation in a child with hypertrophic obstructive cardiomyopathy and Noonan syndrome

We report an 8-year-old child presenting with classical features of hypertrophic obstructive cardiomyopathy and Noonan syndrome with New York Heart Association (NYHA) class III symptoms. Due to progressively worsening symptoms, the child was taken up for percutaneous transluminal septal myocardial ablation, which was successfully performed. Postextrasystolic gradient fell down from 125 to 35 mm Hg. Other than postprocedure bifascicular block, no complications were encountered till 1 year of follow-up.

Septal myectomy after previous septal artery ablation in hypertrophic cardiomyopathy

OBJECTIVE

To review our institution's experience with patients who failed to benefit from septal artery ablation, which necessitated subsequent septal myectomy, and to examine reasons for ablation failure and outcome of myectomy after ablation.

PARTICIPANTS AND METHODS

Of 550 patients who underwent septal myectomy at Mayo Clinic Rochester between January 1, 1999, and December 31, 2006, 16 (3%) had had a total of 22 previous septal artery ablations. This subset of 16 patients was analyzed and compared with a reference group of 120 patients whose septal artery ablations were performed at our institution during this period. Angiograms obtained during septal ablation were available for 13 (81%) of 16 patients in this series and were reviewed by 2 interventional cardiologists (R.A.N. and S.R.O.). These cardiologists also reviewed preoperative and postoperative echocardiography data, hospital course, and follow-up data to compile a list of characteristics that could have contributed to failed ablation.

RESULTS

The median age of the patients at operation was 65 years (interquartile range [IQR], 52-72 years), and interval between ablation and myectomy was 409 days (IQR, 162-568 days). Angiograms revealed 2 failed procedures secondary to technical error. One patient had a relatively large first septal perforator with a large resting gradient. In 10 patients no septal perforators supplying the proximal septum were identified. Postoperatively, mitral regurgitation decreased from 3.00 to 1.00 (P less than .001), and left ventricular outflow tract gradient decreased from 75 mm Hg to 0 mm Hg (IQR, 0-29 mm Hg; P less than .001). Two patients died after surgery: 1 patient developed multiple-organ system failure on postoperative day 7, and 1 patient developed arrhythmia on postoperative day 21. Patients with previous septal artery ablation were older (P=.04), were more likely to have preoperative permanent pacemakers or implantable cardioverter-defibrillators (P=.05), were more likely to require postoperative pacemaker placement (P less than .001), and had higher operative mortality (P less than .001) than control patients. Fourteen patients survived the early recovery phase; 9 were followed up at a median of 1.88 years (IQR, 306 days to 3.3 years). All patients' symptoms improved. Median gradient of the left ventricular outflow tract was 13 mm Hg (IQR, 0-15 mm Hg) at follow-up with mild to moderate (1.6) mitral regurgitation.

CONCLUSION

Septal myectomy performed after failed ablation improves gradient and provides excellent relief of symptoms but is associated with a higher incidence of morbidity and mortality.

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.

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.

Transcoronary ablation of septal hypertrophy does not alter ICD intervention rates in high risk patients with hypertrophic obstructive cardiomyopathy

INTRODUCTION

Transcoronary ablation of septal hypertrophy (TASH) is safe and effectively reduces the intraventricular gradient in patients with hypertrophic obstructive cardiomyopathy (HOCM). To analyze the potential of anti- and proarrhythmic effects of TASH, we studied the discharge rates of implanted cardioverter defibrillators (ICD) in patients with HOCM who are at a high risk for sudden cardiac death.

METHODS

ICD and TASH were performed in 15 patients. Indications for ICD-implantation were secondary prevention in nine patients after resuscitation from cardiac arrest with documented ventricular fibrillation (n = 7) or sustained ventricular tachycardia (n = 2) and primary prevention in 6 patients with a family history of sudden deaths, nonsustained ventricular tachycardia, and/or syncope. All the patients had severe symptoms due to HOCM (NYHA functional class = 2.9).

RESULTS

During a mean follow-up time of 41 +/- 22.7 months following the TASH procedure, 4 patients had episodes of appropriate discharges (8% per year). The discharge rate in the secondary prevention group was 10% per year and 5% in the group with primary prophylactic implants. Three patients died during follow-up (one each of pulmonary embolism, stroke, and sudden death).

CONCLUSION

In conclusion, on the basis of ICD-discharge rates in HOCM-patients at high risk for sudden death, there is no evidence for an unfavorable arrhythmogenic effect of TASH. The efficacy of ICD treatment for the prevention of sudden cardiac death in HOCM could be confirmed, however, mortality is high in this cohort of hypertrophic cardiomyopathy patients.

Percutaneous Transluminal Septal Artery Ablation Using Polyvinyl Alcohol Foam Particles for Septal Hypertrophy in Patients With Hypertrophic Obstructive Cardiomyopathy: Acute and 3-Year Outcomes

PURPOSE

To investigate the effect of septal artery occlusion with transluminally delivered polyvinyl alcohol (PVA) foam particles for the treatment of hypertrophic obstructive cardiomyopathy (HOCM).

METHODS

Percutaneous septal artery ablation was performed in 18 symptomatic patients (13 men; mean age 60+/-17 years, range 28-89) with drug-resistant HOCM. PVA foam particles were mixed with contrast medium and injected through an angiographic catheter under fluoroscopic control until complete stasis in the septal branch was achieved. Patients were monitored with echocardiography and cardiovascular magnetic resonance imaging.

RESULTS

The septal artery was successfully occluded in all patients; no embolization of other coronary branches occurred after infusion of 3 to 8 mL (5.2+/-0.8) of PVA foam particles. The resting pressure gradient was diminished from 83+/-32 to 31+/-35 mmHg (p<0.05). Over a mean follow-up of 44+/-4 months, all patients had symptomatic improvement of their dyspnea and workload without the need for intensified drug therapy. The average NYHA functional class decreased from 3.3+/-0.5 to 1.3+/-0.7 (p<0.0001), with a significant increase in the area of the left ventricular outflow tract (1.3+/-0.2 to 2.6+/-0.2 cm2, p<0.0001). Three instances of transient atrioventricular block occurred, but no complete heart block was produced by the embolization procedure.

CONCLUSIONS

Embolization of the septal artery with PVA foam particles appears effective and safe in this series of patients with hypertrophic obstructive cardiomyopathy. The pure ischemic infarction produced by PVA ablation might be the responsible for the lack of complete heart block and the need for permanent pacing.

Transcoronary ablation of septal hypertrophy for hypertrophic obstructive cardiomyopathy: feasibility, clinical benefit, and short term results in elderly patients

OBJECTIVE

To evaluate symptomatic and haemodynamic results of transcoronary ablation of septal hypertrophy for hypertrophic obstructive cardiomyopathy in elderly patients.

SETTING

Tertiary referral centre for patients with hypertrophic obstructive cardiomyopathy.

DESIGN

Retrospective study of two groups of consecutive patients divided at a median age (59 years).

PATIENTS

Transcoronary ablation of septal hypertrophy was compared for 80 patients (group 1) < 60 years of age and 77 patients (group 2) > or = 60 years of age. At baseline both groups were similar concerning the proportion of familial hypertrophic cardiomyopathy, concomitant moderate hypertension, prior syncope, left ventricular outflow obstruction, left ventricular end diastolic pressure, and left ventricular ejection fraction. Patients in group 2 had a lower interventricular septal thickness and more severe disease as measured by New York Heart Association (NYHA) functional class, exercise capacity, pulmonary artery mean pressure at workload, and cardiac index at peak exercise.

RESULTS

Median follow up was seven months after transcoronary ablation of septal hypertrophy. Both groups had a significant and similar improvement in basal and provokable obstruction, septal thickness, NYHA functional class, exercise tolerance, peak oxygen consumption, and pulmonary artery mean pressure at workload. Significant differences, compared with the younger group, were a higher proportion of persistent total atrioventricular block (5% v 17%, p = 0.015) and a slight decrease in left ventricular ejection fraction (3 (12) v -6 (11)%, p = 0.001) in the elderly, despite a trend to a lower induced peak creatine kinase activity (596 (339) v 491 (331) U/l, p = 0.051).

CONCLUSIONS

Short term results with transcoronary ablation of septal hypertrophy suggest that independent of a patient's age similar treatment strategies are justified in hypertrophic obstructive cardiomyopathy.

Current status of alcohol septal ablation for patients with hypertrophic cardiomyopathy

Since the early 1960s, surgical myotomy-myectomy has been the standard treatment for patients with drug-refractory symptoms due to hypertrophic cardiomyopathy and dynamic outflow tract obstruction. Comparable morphologic and functional results can be achieved by percutaneous septal ablation (PTSMA) by alcohol-induced septal branch occlusion. The circumscribed therapeutic myocardial infarction results in widening of the left ventricular outflow tract with consecutive gradient reduction. Follow-up studies show clinical and objective improvement as well as further gradient reduction due to left ventricular remodeling. In this article, an updated review of the latest results of PTSMA is provided.