Outcome of patients with hypertrophic obstructive cardiomyopathy after percutaneous transluminal septal myocardial ablation and septal myectomy surgery

Inherited Arrhythmias in the Pediatric Population: An Updated Overview

Pediatric cardiomyopathies (CMs) and electrical diseases constitute a heterogeneous spectrum of disorders distinguished by structural and electrical abnormalities in the heart muscle, attributed to a genetic variant. They rank among the main causes of morbidity and mortality in the pediatric population, with an annual incidence of 1.1-1.5 per 100,000 in children under the age of 18. The most common conditions are dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM). Despite great enthusiasm for research in this field, studies in this population are still limited, and the management and treatment often follow adult recommendations, which have significantly more data on treatment benefits. Although adult and pediatric cardiac diseases share similar morphological and clinical manifestations, their outcomes significantly differ. This review summarizes the latest evidence on genetics, clinical characteristics, management, and updated outcomes of primary pediatric CMs and electrical diseases, including DCM, HCM, arrhythmogenic right ventricular cardiomyopathy (ARVC), Brugada syndrome (BrS), catecholaminergic polymorphic ventricular tachycardia (CPVT), long QT syndrome (LQTS), and short QT syndrome (SQTS).

Alcohol Septal Ablation or Septal Myectomy? An Updated Systematic Review and Meta-Analysis of Septal Reduction Therapy for Hypertrophic Obstructive Cardiomyopathy

Objective

To evaluate the safety and effectiveness of alcohol septal ablation (ASA) and septal myectomy (SM) for the treatment of hypertrophic obstructive cardiomyopathy.

Methods

We searched the PubMed, MEDLINE, EMBASE, and CBM databases for observational research articles related to ASA and SM published from the establishment of the databases to November 2021. All ultimate selected articles were highly related to our target. The Newcastle-Ottawa Scale was used to evaluate the literature quality. A fixed or random effect model was performed in the meta-analysis depending on the heterogeneity of the included studies. The Mantel-Haenszelt test with relative risk ratio (RR) and 95% confidence interval (CI) was used to measure the effect indicator of binary data, while the inverse variance method with weighted mean difference (WMD) and 95% CI was used to measure the effect indicator of continuous data.

Results

A totally of 3,647 cases (1,555 cases treated with ASA and 2,092 cases treated with SM) were included. The results of the systematic review indicated no statistically significant difference in postoperative all-cause mortality (RR = 0.82; 95% CI: 0.65–1.04; P = 0.10) between patients treated with ASA and SM, but both the reduction in the postoperative left ventricular outflow tract pressure gradient (WMD = 9.35 mmHg, 95% CI: 5.38–13.31, P < 0.00001) and the post-operative improvement on cardiac function, assessed by the grade of New York Heart Association (NYHA), compared to pre-operative measurements (WMD = 0.13; 95% CI: 0.00–0.26; P < 0.04) in the ASA group were slightly inferior to those in the SM group. In addition, both the risk of pacemaker implantation (RR = 2.83, 95% CI: 2.06–3.88; P < 0.00001) and the risk of reoperation (RR = 11.23, 95% CI: 6.21–20.31; P < 0.00001) are recorded at a higher level after ASA procedure.

Conclusion

Both ASA and SM have a high degree of safety, but the reduction in the postoperative left ventricular outflow tract pressure gradient and the improvement on cardiac function are slightly inferior to SM. In addition, both the risk of pacemaker implantation and the risk of reoperation are recorded at a higher level after ASA procedure. The operative plan should be chosen through multidisciplinary discussions in combination with the wishes of the patients and the actual clinical situation.

Surgical Septal Myectomy for Hypertrophic cardiomyopathy. The Iranian Experience

INTRODUCTION

Hypertrophic obstructive cardiomyopathy (HOCM) is a hereditary heart muscle disorder characterized by significant myocardial hypertrophy. we assessed perioperative and long-term follow-up data of Iranian HOCM patients who underwent SM in 2 pioneering centers.

METHODS

Clinical data of patients with HOCM septal myectomy are collected. Thirty-day outcome and long-term follow-up data for recurrence of gradient and mortality are reported.

RESULTS

Ninety-six patients in two different centers enrolled in the study. Most patients of 52 patients in center 1 were male (34/52 [65.3%]).and the mean age was of 36.7  ±  19 years. Syncope before admission was reported in 5.7%, the mean left ventricular ejection fraction on admission was 53  ±  8%, the mean left ventricular outflow tract gradient was 66.3  ±  20.4 mm Hg, and the mean preoperativeseptal thickness was 25.4  ±  6.7 mm. A redo SM was performed in 3 patients (5.8%), mitral valve repair in 5 patients (9.6%), and atrioventricular repair in 5 patients (9.6%). A residual systolic anterior motion was detected in 4 patients (7.7%), the mean postoperative septal thickness was 19  ±  6 mm (25.1% septal thickness reduction), and in-hospital mortality was 5.8% (n  =  3). A longer-term follow-up showed death in 3 patients (5.8%) and late recurrent left ventricular outflow tract obstruction in 1 patient.

CONCLUSIONS

Transaortic myectomy is an effective surgery with acceptable early and late mortality rates. Improvements in functional status are seen in almost all patients. Appropriate SM is crucial to a good clinical outcome. Long-term survival is excellent and cardiac sudden death is extremely rare after a good surgical treatment.

Urgent percutaneous transluminal septal myocardial ablation for left ventricular outflow tract obstruction exacerbated after surgical aortic valve replacement

Percutaneous transluminal septal myocardial ablation (PTSMA) is an established procedure for treating symptomatic hypertrophic obstructive cardiomyopathy. We report a case of urgent PTSMA for treating refractory heart failure due to exacerbated obstruction of the left ventricular outflow tract after surgical aortic valvular replacement to treat severe aortic stenosis.

Haemodynamic Interplay Between Concomitant Left Ventricular Outflow Tract Obstruction and Aortic Stenosis

The authors describe a patient with hypertrophic cardiomyopathy with concomitant left ventricular outflow tract obstruction and aortic stenosis. Detailed haemodynamic assessment of the serial lesions was performed. Alcohol septal ablation resulted in a significant reduction of gradients across the left ventricular outflow tract.

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

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

Alcohol septal ablation: A useful tool in our arsenal against hypertrophic obstructive cardiomyopathy

OBJECTIVE

Affecting 1 in 500 individuals; hypertrophic cardiomyopathy is an autosomal dominant cardiovascular disorder which is prevalent throughout the world. Surgical myectomy (SM) and alcohol septal ablation (ASA) are two methods currently used for the management of drug refractory hypertrophic obstructive cardiomyopathy (HOCM). ASA may prove to be a useful, less invasive treatment in patients with HOCM METHODS: Electronic literature search was conducted to identify articles that discussed methods to treat drug refractory HOCM. No limits were placed on timing of the publication or the type of article. Keywords and MeSH terms were used and the results were summarized in the relevant section.

RESULTS

Current evidence suggests that alcohol septal ablation is a safe and effective procedure in treating patients with HOCM with similar short- and long-term outcomes when compared with SM.

CONCLUSION

ASA has been shown to be a safe and reliable procedure; imaging techniques and dedicated multi-disciplinary teams can be used to select patients with HOCM. Though SM is recommended as gold standard treatment for drug refractory HOCM, ASA may play an increasing role in the near future due an ageing population; both ASA and SM can have a beneficial role in treating those who are affected by HOCM when the appropriate group of patients are selected for each intervention.

Effects of surgical septal myectomy on survival in patients with hypertrophic obstructive cardiomyopathy

Objective:

The purpose of this study was to determine the effects of surgical resection of muscle layer on the long-term survival of patients with hypertrophic obstructive cardiomyopathy (HOCM).

Methods:

The original study cohort consisted of 552 patients with hypertrophic cardiomyopathy (HCM), including 380 patients with HOCM and 172 patients with nonobstructive HCM. All these patients had a definite diagnosis in our center from October 1, 2009, to December 31, 2012. They were divided into three groups, viz., HOCM with myectomy group (n=194), nonoperated HOCM group (n=186), and nonobstructive HCM group (n=172). Median follow-up duration was 57.57±13.71 months, and the primary end point was a combination of mortality from all causes.

Results:

In this survival study, we compared the prognoses of patients with HOCM after myectomy, patients with nonoperated HOCM, and patients with nonobstructive HCM. Among the three groups, the myectomy group showed a lower rate of reaching the all-cause mortality with statistically indistinguishable overall survival compared with patients with nonobstructive HCM (p=0.514). Among patients with left ventricular outflow tract (LVOT) obstruction, the overall survival in the myectomy group was noticeably better than that in the nonoperated HOCM group (log-rank p<0.001). Parameters that showed a significant univariate correlation with survival included age, previous atrial fibrillation (AF), NT-proBNP, Cr, myectomy, and LV ejection fraction. When these variables were entered in the multivariate model, the only independent predictors of survival were myotomy [hazard ratio (HR): 0.109; 95% CI: 0.013–0.877, p<0.037], age (HR: 1.047; 95% CI: 1.007–1.088, p=0.021), and previous AF (HR: 2.659; 95% CI: 1.022–6.919, p=0.021).

Conclusion:

Patients with HOCM undergoing myectomy appeared to suffer from a lower risk of reaching the all-cause mortality and demonstrated statistically indistinguishable overall survival compared with patients with nonobstructive HCM. Multivariate analysis clearly demonstrated myectomy as a powerful, independent factor of survival, confirming that the differences in long-term survival recorded in this study may be due to surgical improvement in the LVOT gradient.

Hypertrophic Cardiomyopathy and the Brockenbrough-Braunwald-Morrow Phenomenon: A Case Report

The Brockenbrough-Braunwald-Morrow phenomenon provides objective evidence of the existence and degree of left ventricular outflow tract (LVOT) obstruction, which can be improved with pharmacological therapy, surgical myectomy, or interventional alcohol septal ablation (ASA). This article incorporates contemporary research findings that are useful for the diagnosis and management of this entity.

We present the case of a 67-year-old lady with a past medical history significant for hypertension, hyperlipidemia, and coronary artery disease. The patient presented with a complaint of functional class-3 dyspnea on exertion with associated substernal chest tightness radiating to her back that had been worsening for two days prior to admission. An echocardiogram showed left ventricular hypertrophy with septal predominance measuring 17.5 mm in end-diastole and a left ventricular ejection fraction greater than 65%. The LVOT peak gradient was elevated and a positive Brockenbrough-Braunwald-Morrow phenomenon was observed for which a septal myectomy and coronary bypass of the left internal mammary artery (LIMA) to the left anterior descending (LAD) artery were performed. The patient had an uneventful postoperative course and her symptoms improved significantly.

The Brockenbrough-Braunwald-Morrow phenomenon is useful to determine the degree of LVOT and to confirm the resolution of obstruction after treatment.

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.

Hypertrophic obstructive cardiomyopathy: review of surgical treatment

Hypertrophic cardiomyopathy ranks among the most common congenital cardiac diseases, affecting up to 1 in 200 of the general population. When it causes left ventricular outflow tract obstruction, treatment is guided to reduce symptoms and the risk of sudden cardiac death. Pharmacologic therapy is the first-line treatment, but when it fails, surgical myectomy or percutaneous ablation of the hypertrophic myocardium are the standard therapies to eliminate subaortic obstruction. Both surgical myectomy and percutaneous ablation are proven safe and effective treatments; however, myectomy is the gold standard with a significantly lower complication rate and more complete and lasting reduction of left ventricular outflow tract obstruction.

Septal myectomy after failed septal alcohol ablation

Despite septal myectomy remaining the gold standard septal reduction therapy for hypertrophic obstructive cardiomyopathy (HOCM), there has been a disproportionate use of alcohol septal ablation (ASA) worldwide. Absolute resolution of left ventricular outflow tract (LVOT) obstruction with ASA is not achieved in a substantial proportion of patients. The mechanisms of failure from ASA are partially understood and described. Residual obstruction in hypertrophic cardiomyopathy is associated with worse clinical outcomes and mortality. There is a growing number of patients who present with significant residual gradients after ASA and require a rescue septal myectomy operation, which then carries an increased risk of perioperative complications and life-long sequelae. This contrasts with the excellent outcomes achieved by septal myectomy without previous percutaneous intervention. Despite complete resolution of obstruction in rescue myectomy, the outcomes remain compromised by the prior ASA.

Incidence of Atrial Fibrillation following Alcohol Septal Ablation for Hypertrophic Cardiomyopathy

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Microvascular permeability changes might explain cardiac tamponade after alcohol septal ablation for hypertrophic cardiomyopathy

Various sequelae of alcohol septal ablation for hypertrophic obstructive cardiomyopathy have been reported. Of note, some cases of cardiac tamponade after alcohol septal ablation cannot be well explained. We describe the case of a 78-year-old woman with hypertrophic obstructive cardiomyopathy in whom cardiac tamponade developed one hour after alcohol septal ablation, probably unrelated to mechanical trauma. At that time, we noted a substantial difference in the red blood cell-to-white blood cell ratio between the pericardial effusion (1,957.4) and the peripheral blood (728.3). In addition to presenting the patient's case, we speculate that a possible mechanism for acute tamponade--alcohol-induced changes in microvascular permeability--is a reasonable explanation for cases of alcohol septal ablation that are complicated by otherwise-unexplainable massive pericardial effusions.

Percutaneous Septal Ablation in Hypertrophic Obstructive Cardiomyopathy: From Experiment to Standard of Care

Hypertrophic cardiomyopathy (HCM) is one of the more common hereditary cardiac conditions. According to presence or absence of outflow obstruction at rest or with provocation, a more common (about 60-70%) obstructive type of the disease (HOCM) has to be distinguished from the less common (30-40%) nonobstructive phenotype (HNCM). Symptoms include exercise limitation due to dyspnea, angina pectoris, palpitations, or dizziness; occasionally syncope or sudden cardiac death occurs. Correct diagnosis and risk stratification with respect to prophylactic ICD implantation are essential in HCM patient management. Drug therapy in symptomatic patients can be characterized as treatment of heart failure with preserved ejection fraction (HFpEF) in HNCM, while symptoms and the obstructive gradient in HOCM can be addressed with beta-blockers, disopyramide, or verapamil. After a short overview on etiology, natural history, and diagnostics in hypertrophic cardiomyopathy, this paper reviews the current treatment options for HOCM with a special focus on percutaneous septal ablation. Literature data and the own series of about 600 cases are discussed, suggesting a largely comparable outcome with respect to procedural mortality, clinical efficacy, and long-term outcome.

A case of hypertrophic obstructive cardiomyopathy with aortic stenosis

A 78-year-old woman complained of experiencing dyspnea (New York Heart Association II) and faintness. Echocardiography revealed she had asymmetric left ventricular hypertrophy, and a dynamic left ventricular outflow tract (LVOT) obstruction due to systolic anterior motion of the mitral valve. It also revealed calcification of the noncoronary cusp and a high-flow velocity in the LVOT (6.3 m/s). The planimetry measurement with transesophageal echocardiography was 0.89 cm² (aortic valve area/body surface area: 0.69 cm²/m²). Later, she was diagnosed with hypertrophic obstructive cardiomyopathy (HOCM) and aortic stenosis (AS). However, during the catheterization, the transvalvular pressure gradient (PG) was only 25 mmHg. In order to solve this, we performed a percutaneous transluminal septal myocardial ablation. As a result, the PG of the LVOT decreased from 152 mmHg to 25 mmHg. We first thought that the LVOT obstruction had reduced the flow passing through the aortic valve, and restricted the motion of the aortic valve leaflets. We also considered the possibility that the aortic valve area had been underestimated. The hemodynamic study played an important role in the decision for the treatment plan. The present case was a combination of HOCM and "mild" AS. <Learning objective: We know that we can distinguish between a left ventricular outflow tract obstruction and aortic stenosis using continuous-wave Doppler according to the phase of the peak gradient. However, if both are present, it is uncertain whether we can distinguish between them. It is necessary to measure the subaortic pressure and flow passing through the aortic valve accurately by catheterization in order to know which is the chief pathology.>.

Management of hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is clinically defined as unexplained myocardial hypertrophy, and it is an autosomal dominant disease of the cardiac sarcomere. It is present in 1 in 500 in the general adult population, making it the most common genetic cardiovascular disease. The pathophysiology of HCM is complex, leading to significant variability in clinical presentation. This, combined with the lack of randomized trials, makes the management of these patients difficult.

FINDINGS

The majority of patients with HCM are asymptomatic without a substantial reduction in survival. However, a considerable portion of patients will experience significant symptoms and HCM-related death, and effective therapies are available for these patients. Patients may have symptoms of heart failure from outflow tract obstruction and/or restrictive physiology. Medical therapy targeted at the underlying pathophysiology should be used, and surgical myectomy or alcohol septal ablation is available for those with refractory symptoms. While the overall risk of sudden cardiac death (SCD) is low in HCM patients, some are at elevated risk for and experience SCD, a devastating outcome in young patients. Risk stratification for SCD and treatment with implantable cardioverter-defibrillators is paramount. Many HCM patients will also develop atrial fibrillation, and this is often poorly tolerated. A rhythm control strategy with antiarrhythmic drugs or catheter ablation is often necessary, and anticoagulation should be administered to reduce the risk of thromboembolism. Finally, family members of patients with HCM should be regularly screened with electrocardiography and echocardiography.

CONCLUSIONS

HCM is a complex disease with heterogeneous phenotypes and clinical manifestations. The management of HCM focuses on reducing symptoms of heart failure, preventing SCD, treating atrial fibrillation, and screening family members. Treatment should be tailored to the unique characteristics of each individual patient.

Recent advances in genetics and treatment of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is an intriguing disease with various clinical manifestations, ranging from sudden cardiac death to heart failure. The molecular genetics of HCM are all but elucidated and over 200 mutations in more than a dozen genes have been identified. Conventional therapeutic agents, namely beta-blockers and calcium channel blockers, could provide symptomatic relief but are not known to reduce mortality or induce regression of phenotype. Studies in genetic animal models suggest cardiac hypertrophy and fibrosis, a major histological feature of HCM, may be reversed or prevented through blockade of molecules involved in the pathogenesis of HCM. Surgical myomectomy and ethanol-induced septal ablation are effective procedures for reducing the left ventricular outflow tract obstruction and hence, symptomatic improvement. Randomized studies are needed to compare the effectiveness of medical therapy, ethanol septal ablation and surgical myomectomy in treatment of patients with HCM.

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.

Controversies in cardiovascular medicine. Benefits of surgery in obstructive hypertrophic cardiomyopathy: bring septal myectomy back for European patients

Hypertrophic cardiomyopathy (HCM), a heterogeneous genetic heart disease with global distribution, is an important cause of heart failure disability at any age. For 50 years, surgical septal myectomy has been the preferred and primary treatment strategy for most HCM patients with progressive, drug refractory functional limitation due to left ventricular (LV) outflow tract obstruction. With very low surgical mortality at experienced centres, septal myectomy reliably abolishes impedance to LV outflow and heart failure-related symptoms, restores quality of life, and importantly is associated with long-term survival similar to that in the general population. Nevertheless, alternatives to surgical management are necessary for selected HCM patients. For example, after a brief flirtation with dual-chamber pacing 20 years ago, percutaneous alcohol septal ablation has garnered a large measure of enthusiasm and a dedicated following in the interventional cardiology community, achieving benefits for patients, paradoxically, by virtue of producing a transmural myocardial infarct. However, an unintended consequence has been the virtual obliteration of the surgical option for HCM patients in Europe, where several robust myectomy programmes once existed. Therefore, clear differences are now evident internationally regarding management strategies for symptomatic obstructive HCM. The surgical option is now unavailable to many patients based solely on geography, including some who would likely benefit more substantially from surgical myectomy than from catheter-based alcohol ablation. It is our aspiration that this discussion will generate reconsideration and resurgence of interest in surgical septal myectomy as a treatment option for severely symptomatic obstructive HCM patients within Europe.

Alcohol Septal Ablation for the Treatment of Hypertrophic Obstructive Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is an inherited myocardial disorder characterised by left ventricular hypertrophy. A subgroup of patients develops limiting symptoms in association with left ventricular outflow tract obstruction (LVOTO). Current international guidelines recommend that symptomatic patients are initially treated by alleviating exacerbating factors and negatively inotropic medication. Drug-refractory symptoms require a comprehensive evaluation of the mechanism of LVOTO and review by a multidisciplinary team to consider the relative merits of myectomy, alcohol septal ablation (ASA) and pacing. This article provides a brief overview of HCM and the pathophysiology of LVOTO, and reviews the use of ASA in patients with drug-refractory symptoms secondary to LVOTO.

Peak systolic longitudinal strain of the lateral left ventricular wall improves after septal ablation for symptomatic hypertrophic obstructive cardiomyopathy: a follow-up study using speckle tracking echocardiography

Speckle tracking echocardiography (STE) or two-dimensional (2D) strain imaging is a novel ultrasound method to assess myocardial deformation. Peak systolic longitudinal strain (PSLS) of the basal septum (IVS) and the opposite lateral (LVFW) wall were measured in addition to standard echocardiography in 88 consecutive patients (pts) with obstructive hypertrophic cardiomyopathy (HOCM) who underwent a septal ablation procedure (PTSMA) and who were re-evaluated 12 ± 12 after months. At baseline, PSLS was substantially reduced both in basal regions. While PSLS remained unchanged in the basal IVS, i.e. the target region for PTSMA (baseline: -5.3 ± 4.1%; follow-up: -6.0 ± 4.3%; P=0.06), it improved in the opposite LVFW (from -9.4 ± 4.7 to -12.4 ± 4.8%; P<0.0001). Wall thickness decreased in both regions (Septum: from 20 ± 4 to 17 ± 4 mm; P<0.0001; LV free wall: from 13 ± 2 to 12 ± 2 mm; P=0.001). PSLS correlated significantly with wall thickness, both at baseline and at follow-up. NYHA functional class (from 2.9 ± 0.4 to 1.6 ± 0.6; P<0.0001) and objective exercise capacity (from 96 ± 42 to 114 ± 42 W; P=0.001) improved together with the reduction of outflow obstruction (LVOTO: from 62 ± 30 to 11 ± 19 mm Hg at rest, from 121 ± 26 to 43 ± 40 mm Hg with provocation; P<0.0001). During the 12 months of observation, no patient had a severe adverse event. Regional myocardial deformation can be assessed quantitatively by STE. Reduction of LV afterload by elimination of the outflow gradient following a successful PTSMA with low doses of alcohol results in improvement of systolic lateral longitudinal function.

Meta-Analyses of Septal Reduction Therapies for Obstructive Hypertrophic Cardiomyopathy

Background— Septal reduction for obstructive hypertrophic cardiomyopathy may be performed by surgical myectomy or alcohol septal ablation (ASA). Unlike surgical myectomy, ASA creates an intramyocardial scar that may potentiate the risk of ventricular arrhythmias and sudden cardiac death (SCD).

Methods and Results— Systematic reviews for ASA and surgical myectomy were performed. Study selection and data extraction were completed independently by 2 investigators. Comparative data analyses were completed using a random effects model and regression analysis. Kappa statistics for agreement on initial study inclusion were high for both ASA (0.78; 95% CI, 0.68 to 0.88) and surgical myectomy studies (0.95; 95% CI, 0.84 to 1.0). Nineteen ASA studies (2207 patients) and 8 surgical myectomy studies (1887 patients) were included. Median follow-up was shorter for ASA than for myectomy studies (51 versus 1266 patient-years; P <0.001). For ASA and surgical myectomy, unadjusted rates (events/patient-years) of all-cause mortality (0.021 versus 0.018, respectively; P =0.37) and SCD (0.004 versus 0.003, respectively; P =0.36) were similar. Patients treated with ASA were older (weighted mean, 55 versus 44 years; P <0.001) and had less septal hypertrophy (weighted mean, 21 versus 23 mm; P <0.001) compared with those treated with myectomy. After adjustment for available baseline characteristics, odds ratios for treatment effect on all-cause mortality and SCD were 0.28 (95% CI, 0.16 to 0.46) and 0.32 (95% CI, 0.11 to 0.97), respectively, favoring ASA.

Conclusions— Rates of all-cause mortality and SCD after both ASA and surgical myectomy were similarly low. Adjusted for baseline characteristics, the odds ratios for treatment effect on all-cause mortality and SCD were lower in ASA cohorts compared with surgical myectomy cohorts.

Effects of exercise on the duration of diastole and on interventricular phase differences in patients with hypertrophic cardiomyopathy: relationship to cardiac output reserve

BACKGROUND

Our study sought to characterize the effect of exercise on the duration of left ventricular (LV) diastole and interventricular dyssynchrony in patients with hypertrophic cardiomyopathy (HCM). We hypothesized that an abnormally shortened diastolic time may adversely affect cardiac performance.

METHODS

We studied 49 symptomatic patients with HCM during incremental exercise. Twenty-nine patients had obstructive disease (HOCM) and 20 no resting or provocable gradient (HNCM). Right heart catheterization and high temporal resolution radionuclide angiography were simultaneously performed. The loss of diastolic time per beat (LDT(RR)) was quantified using a regression equation obtained from a healthy control group (n = 30).

RESULTS

During rest and peak exercise, a significant shortening of the relative duration of LV diastole (35.6 +/- 5 vs. 38.0 +/- 3 s/min and 29.3 +/- 6 vs. 32.4 +/- 3 s/min; P < or = .02) and an increased interventricular phase delay were evident in patients with HOCM compared to controls. Baseline and peak exercise LDT(RR) values were inversely related to cardiac output reserve and exercise duration. In multivariate analysis, LDT(RR) at peak exercise was identified as an independent predictor of cardiac output reserve.

CONCLUSIONS

In HOCM, baseline abnormalities of the relative duration of LV systolic and diastolic time aggravate during exercise. The disproportionate shortening of diastolic time may significantly impair cardiac efficiency by restricting diastolic filling.

Outcome of alcohol septal ablation for obstructive hypertrophic cardiomyopathy

BACKGROUND

The clinical efficacy of alcohol septal ablation for drug-refractory hypertrophic cardiomyopathy remains unclear. This study examines the outcome of alcohol septal ablation performed at a tertiary hypertrophic cardiomyopathy referral center.

METHODS AND RESULTS

Among 601 patients with severely symptomatic obstructive hypertrophic cardiomyopathy referred for alcohol septal ablation or myectomy from 1998 to 2006, 138 patients (median age, 64 years; 39% men) chose to undergo ablation. Procedural complications included death in 1.4%, sustained ventricular arrhythmias in 3%, tamponade in 3%, and pacemaker implantation in 20%. This rate was higher than a combined complication rate of 5% in age- and gender-matched patients who had undergone septal myectomy at Mayo Clinic (P<0.0001). Four-year survival free of all mortality was 88.0% (95% confidence interval, 79.4 to 97.5%), which was similar to that of the age- and gender-matched patients who had undergone myectomy (P=0.18). Six patients had documented ventricular arrhythmias after ablation, 4 of whom had successful intervention. Four-year survival free of death and severe New York Heart Association class III/IV symptoms after septal ablation was 76.4%, and 71 patients (51%) became asymptomatic. Myectomy patients <or=65 years of age had significantly better survival free of death and severe symptoms (P=0.01).

CONCLUSIONS

Alcohol septal ablation is an efficacious procedure if performed in an experienced institution and may resolve symptoms in a subset of patients with obstructive hypertrophic cardiomyopathy. However, the procedural complication rate exceeds that of myectomy. Patients 65 years of age have better symptom resolution with myectomy. No impairment in short-term survival was noted in this nonrandomized study, but the long-term outcome remains unknown.

[Evolution of the surgical strategy in hypertrophic cardiomyopathy: case studies of eight patients]

INTRODUCTION

Hypertrophic cardiomyopathy is an inherited disease characterized by a left ventricular hypertrophy, a diastolic dysfunction and rhythm troubles with risk of sudden death. There was an evolution in the surgical strategy to treat the patients who present a left ventricular outflow tract gradient.

MATERIALS AND METHODS

A retrospective study was conducted: We selected eight cases who presented an hypertrophic cardiomyopathy and operated on. Pre and post operative echocardiographic data were analysed. Follow up was obtained by call or mail to the cardiologist.

RESULTS

The patients were classified in four groups: isolated left ventricular outflow tract obstruction, left ventricular outflow tract obstruction and associated lesions, obstructive hypertrophic cardiomyopathy and endocarditis, post operative complications of the hypertrophic cardiomyopathy surgery. We observed a significant decrease of the left ventricular outflow tract mean gradient in the post operative period and at four years.

CONCLUSION

Surgical management of obstructive hypertrophic cardiomyopathy remain an important option in young patients, in case of failure of the ethanol septal ablation or in patients who present other surgical lesions. The dual chamber stimulation remain indicated in old patients.

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.