Echocardiographic insights into the mechanisms of relief of left ventricular outflow tract obstruction after nonsurgical septal reduction therapy in patients with hypertrophic obstructive cardiomyopathy

Treatment of Severe Left Ventricular Outflow Tract Obstruction and Mitral Regurgitation With Alcohol Septal Ablation

•

Hypertrophic cardiomyopathy is a common genetic heart disease.

•

Patients can have variable clinical manifestations and severity of disease.

•

Manifestations include LVOT obstruction and MR.

•

Alcohol septal ablation can successfully treat LVOT obstruction and MR.

Recommendations for Multimodality Cardiovascular Imaging of Patients with Hypertrophic Cardiomyopathy: An Update from the American Society of Echocardiography, in Collaboration with the American Society of Nuclear Cardiology, the Society for Cardiovascular Magnetic Resonance, and the Society of Cardiovascular Computed Tomography

Hypertrophic cardiomyopathy (HCM) is defined by the presence of left ventricular hypertrophy in the absence of other potentially causative cardiac, systemic, syndromic, or metabolic diseases. Symptoms can be related to a range of pathophysiologic mechanisms including left ventricular outflow tract obstruction with or without significant mitral regurgitation, diastolic dysfunction with heart failure with preserved and heart failure with reduced ejection fraction, autonomic dysfunction, ischemia, and arrhythmias. Appropriate understanding and utilization of multimodality imaging is fundamental to accurate diagnosis as well as longitudinal care of patients with HCM. Resting and stress imaging provide comprehensive and complementary information to help clarify mechanism(s) responsible for symptoms such that appropriate and timely treatment strategies may be implemented. Advanced imaging is relied upon to guide certain treatment options including septal reduction therapy and mitral valve repair. Using both clinical and imaging parameters, enhanced algorithms for sudden cardiac death risk stratification facilitate selection of HCM patients most likely to benefit from implantable cardioverter-defibrillators.

Survival Following Alcohol Septal Ablation or Septal Myectomy for Patients With Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

There is little information regarding long-term mortality comparing the 2 most common procedures for septal reduction for obstructive hypertrophic cardiomyopathy (HCM), alcohol septal ablation (ASA), and septal myectomy.

OBJECTIVES

This study sought to compare the long-term mortality of patients with obstructive HCM following septal myectomy or ASA.

METHODS

We evaluated outcomes of 3,859 patients who underwent ASA or septal myectomy in 3 specialized HCM centers. All-cause mortality was the primary endpoint of the study.

RESULTS

In the study cohort, 585 (15.2%) patients underwent ASA, and 3,274 (84.8%) underwent septal myectomy. Patients undergoing ASA were significantly older (median age: 63.0 years [IQR: 52.7-72.8 years] vs 53.7 years [IQR: 44.9-62.8 years]; P < 0.001) and had smaller septal thickness (19.0 mm [IQR: 17.0-22.0 mm] vs 20.0 mm [IQR: 17.0-23.0 mm]; P = 0.007). Patients undergoing ASA also had more comorbidities, including renal failure, diabetes, hypertension, and coronary artery disease. There were 4 (0.7%) early deaths in the ASA group and 9 (0.3%) in the myectomy group. Over a median follow-up of 6.4 years (IQR: 3.6-10.2 years), the 10-year all-cause mortality rate was 26.1% in the ASA group and 8.2% in the myectomy group. After adjustment for age, sex, and comorbidities, the mortality remained greater in patients having septal reduction by ASA (HR: 1.68; 95% CI: 1.29-2.19; P < 0.001).

CONCLUSIONS

In patients with obstructive hypertrophic cardiomyopathy, ASA is associated with increased long-term all-cause mortality compared with septal myectomy. This impact on survival is independent of other known factors but may be influenced by unmeasured confounding patient characteristics.

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

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

Left atrial remodeling postseptal myectomy for severe obstructive hypertrophic cardiomyopathy: Analysis by two-dimensional speckle-tracking echocardiography

BACKGROUND

Septal myectomy relieves left ventricular outflow obstruction (LVOTO) and is associated with excellent long-term outcomes. LVOTO is associated with diastolic dysfunction and increased left atrial (LA) size. We sought to investigate the changes in LA volumes and function postmyectomy and the association between these changes with clinical outcomes postmyectomy.

METHODS

Sixty-six hypertrophic cardiomyopathy patients undergoing myectomy were retrospectively studied. Preprocedural and 6- to 18-month postmyectomy follow-up transthoracic echocardiographic images were obtained. LA volumes and strain were assessed by two-dimensional speckle-tracking echocardiography.

RESULTS

Left atrial volumes, that is, indexed maximal, minimal, and pre-A volumes reduced postmyectomy, yet remained increased compared to controls (105.6 ± 34.5 mL vs 84.9 ± 26.7 mL, 45.2 ± 25.7 mL vs 35.4 ± 22.6 mL, 70.1 ± 31.4 mL vs 35.4 ± 22.6 mL, respectively, P < 0.05). The total emptying index did not improve postmyectomy and remained lower than controls (58.6 ± 12.4 vs 59.9 ± 12.8, P = NS) whereas atrial contraction improved, yet did not normalize (active emptying index 36.1 ± 14.9 vs 41.1 ± 16.2, P < 0.05). The conduit volume remained reduced postmyectomy (18.6 ± 13.3 mL vs 16.6 ± 15.1 mL, P = NS). LA strain also did not improve postmyectomy (26.8 ± 7.3 vs 28.5 ± 8.8, P = NS). A multivariable logistic regression identified preprocedural E/e' ratio and indexed maximal LA volume, as independent predictors for LA volume reduction ≥20% postmyectomy. During a mean follow-up of 4.9 ± 2.3 years postmyectomy, 24.2% of the patients developed atrial fibrillation and <5% of patients were severely symptomatic. We found no associations between LA volumes/function and atrial fibrillation or symptoms postmyectomy.

CONCLUSION

Postmyectomy LA volumes decreased, and the contractile function improved. There was no association between LA volumes/function and clinical outcomes postmyectomy. Notably, the LA remained enlarged (though to a lesser degree) with reduced strain and emptying fraction, suggesting possible atrial myopathy.

Hypertrophic cardiomyopathy with dynamic obstruction and high left ventricular outflow gradients associated with paradoxical apical ballooning

BACKGROUND

Acute left ventricular (LV) apical ballooning with normal coronary angiography occurs rarely in obstructive hypertrophic cardiomyopathy (OHCM); it may be associated with severe hemodynamic instability.

METHODS, RESULTS

We searched for acute LV ballooning with apical hypokinesia/akinesia in databases of two HCM treatment programs. Diagnosis of OHCM was made by conventional criteria of LV hypertrophy in the absence of a clinical cause for hypertrophy and mitral-septal contact. Among 1519 patients, we observed acute LV ballooning in 13 (0.9%), associated with dynamic left ventricular outflow tract (LVOT) obstruction and high gradients, 92 ± 37 mm Hg, 10 female (77%), age 64 ± 7 years, LVEF 31.6 ± 10%. Septal hypertrophy was mild compared to that of the rest of our HCM cohort, 15 vs 20 mm (P < 0.00001). An elongated anterior mitral leaflet or anteriorly displaced papillary muscles occurred in 77%. Course was complicated by cardiogenic shock and heart failure in 5, and refractory heart failure in 1. High-dose beta-blockade was the mainstay of therapy. Three patients required urgent surgical relief of LVOT obstruction, 2 for refractory cardiogenic shock, and one for refractory heart failure. In the three patients, surgery immediately normalized refractory severe LV dysfunction, and immediately reversed cardiogenic shock and heart failure. All have normal LV systolic function at 45-month follow-up, and all have survived.

CONCLUSIONS

Acute LV apical ballooning, associated with high dynamic LVOT gradients, may punctuate the course of obstructive HCM. The syndrome is important to recognize on echocardiography because it may be associated with profound reversible LV decompensation.

Alcohol Septal Ablation for Obstructive Hypertrophic Cardiomyopathy: A Word of Endorsement

Twenty years after the introduction of alcohol septal ablation (ASA) for the treatment of obstructive hypertrophic cardiomyopathy, the arrhythmogenicity of the ablation scar appears to be overemphasized. When systematically reviewing all studies comparing ASA with myectomy with long-term follow-up, (aborted) sudden cardiac death and mortality rates were found to be similarly low. The focus should instead shift toward lowering the rate of reinterventions and pacemaker implantations following ASA because, in this area, ASA still seems inferior to myectomy. Part of the reason for this difference is that ASA is limited by the route of the septal perforators, whereas myectomy is not. Improvement may be achieved by: 1) confining ASA to hypertrophic cardiomyopathy centers of excellence with high operator volumes; 2) improving patient selection using multidisciplinary heart teams; 3) use of (3-dimensional) myocardial contrast echocardiography for selecting the correct septal (sub)branch; and 4) use of appropriate amounts of alcohol for ASA.

Alcohol Septal Ablation to Reduce Heart Failure

Hypertrophic cardiomyopathy is a commonly encountered inheritable cardiac disorder with variable phenotypic expression. Although most patients will have no or mild symptoms, 10% will develop heart failure symptoms refractory to medical management. This article discusses the mechanisms through which hypertrophic cardiomyopathy induces heart failure and how alcohol septal ablation can reverse each of these mechanisms to lead to clinical improvement.

The role of imaging in the diagnosis and management of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy, affecting approximately 1:500 people. As the yield of genetic testing is only about 35-60%, the diagnosis of HCM is still clinical and based on the demonstration of unexplained and usually asymmetric left ventricular (LV) hypertrophy by imaging modalities. In the past, echocardiography was the sole imaging modality used for the diagnosis and management of HCM. However, in recent years other imaging modalities such as cardiac magnetic resonance have played a major role in the diagnosis, management and risk stratification of HCM, particularly when the location of left ventricular hypertrophy is atypical (apex, lateral wall) and when the echocardiographic imaging is sub-optimal. However, the most unique contribution of cardiac magnetic resonance is the quantification of myocardial fibrosis. Exercise stress echocardiography is the preferred provocative test for the assessment of LV outflow tract obstruction, which is detected only on provocation in one-third of the patients.

Role of multimodality cardiac imaging in the management of patients with hypertrophic cardiomyopathy: an expert consensus of the European Association of Cardiovascular Imaging Endorsed by the Saudi Heart Association

Taking into account the complexity and limitations of clinical assessment in hypertrophic cardiomyopathy (HCM), imaging techniques play an essential role in the evaluation of patients with this disease. Thus, in HCM patients, imaging provides solutions for most clinical needs, from diagnosis to prognosis and risk stratification, from anatomical and functional assessment to ischaemia detection, from metabolic evaluation to monitoring of treatment modalities, from staging and clinical profiles to follow-up, and from family screening and preclinical diagnosis to differential diagnosis. Accordingly, a multimodality imaging (MMI) approach (including echocardiography, cardiac magnetic resonance, cardiac computed tomography, and cardiac nuclear imaging) is encouraged in the assessment of these patients. The choice of which technique to use should be based on a broad perspective and expert knowledge of what each technique has to offer, including its specific advantages and disadvantages. Experts in different imaging techniques should collaborate and the different methods should be seen as complementary, not as competitors. Each test must be selected in an integrated and rational way in order to provide clear answers to specific clinical questions and problems, trying to avoid redundant and duplicated information, taking into account its availability, benefits, risks, and cost.

Successful percutaneous transluminal septal myocardial ablation through a right superior septal artery for a patient with hypertrophic obstructive cardiomyopathy

Percutaneous transluminal septal myocardial ablation (PTSMA) has been widely accepted as a therapeutic option for patients with hypertrophic obstructive cardiomyopathy (HOCM). To achieve success in PTSMA, we need to explore the target septal arteries, including any anomalous branches that feed the hypertrophic septal myocardium causing left ventricular outflow tract obstruction. An HOCM case in which PTSMA was performed through a dominant right superior septal (RSS) artery is presented. In cases without an effective septal branch artery arising from the left anterior descending artery, an RSS artery should be sought as an alternative route for PTSMA.

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.

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.

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.

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.

Experimental therapies in hypertrophic cardiomyopathy

The quintessential clinical diagnostic phenotype of human hypertrophic cardiomyopathy (HCM) is primary cardiac hypertrophy. Cardiac hypertrophy is also a major determinant of mortality and morbidity including the risk of sudden cardiac death (SCD) in patients with HCM. Reversal and attenuation of cardiac hypertrophy and its accompanying fibrosis is expected to improve morbidity as well as decrease the risk of SCD in patients with HCM.The conventionally used pharmacological agents in treatment of patients with HCM have not been shown to reverse or attenuate established cardiac hypertrophy and fibrosis. An effective treatment of HCM has to target the molecular mechanisms that are involved in the pathogenesis of the phenotype. Mechanistic studies suggest that cardiac hypertrophy in HCM is secondary to activation of various hypertrophic signaling molecules and, hence, is potentially reversible. The hypothesis is supported by the results of genetic and pharmacological interventions in animal models. The results have shown potential beneficial effects of angiotensin II receptor blocker losartan, mineralocorticoid receptor blocker spironolactone, 3-hydroxy-3-methyglutaryl-coenzyme A reductase inhibitors simvastatin and atorvastatin, and most recently, N-acetylcysteine (NAC) on reversal or prevention of hypertrophy and fibrosis in HCM. The most promising results have been obtained with NAC, which through multiple thiol-responsive mechanisms completely reversed established cardiac hypertrophy and fibrosis in three independent studies. Pilot studies with losartan and statins in humans have established the feasibility of such studies. The results in animal models have firmly established the reversibility of established cardiac hypertrophy and fibrosis in HCM and have set the stage for advancing the findings in the animal models to human patients with HCM through conducting large-scale efficacy studies.

Echocardiography-guided interventions

A major advantage of echocardiography over other advanced imaging modalities (magnetic resonance imaging, computed tomographic angiography) is that echocardiography is mobile and real time. Echocardiograms can be recorded at the bedside, in the cardiac catheterization laboratory, in the cardiovascular intensive care unit, in the emergency room-indeed, any place that can accommodate a wheeled cart. This tremendous advantage allows for the performance of imaging immediately before, during, and after various procedures involving interventions. The purpose of this report is to review the use of echocardiography to guide interventions. We provide information on the selection of patients for interventions, monitoring during the performance of interventions, and assessing the effects of interventions after their completion. In this document, we address the use of echocardiography in commonly performed procedures: transatrial septal catheterization, pericardiocentesis, myocardial biopsy, percutaneous transvenous balloon valvuloplasty, catheter closure of atrial septal defects (ASDs) and patent foramen ovale (PFO), alcohol septal ablation for hypertrophic cardiomyopathy, and cardiac electrophysiology. A concluding section addresses interventions that are presently investigational but are likely to enter the realm of practice in the very near future: complex mitral valve repairs, left atrial appendage (LAA) occlusion devices, 3-dimensional (3D) echocardiographic guidance, and percutaneous aortic valve replacement. The use of echocardiography to select and guide cardiac resynchronization therapy has recently been addressed in a separate document published by the American Society of Echocardiography and is not further discussed in this document. The use of imaging techniques to guide even well-established procedures enhances the efficiency and safety of these procedures.

Relation of immediate decrease in ventricular septal strain after alcohol septal ablation for obstructive hypertrophic cardiomyopathy to long-term reduction in left ventricular outflow tract pressure gradient

Alcohol septal ablation (ASA) aims to decrease left ventricular outflow tract (LVOT) obstruction in patients with obstructive hypertrophic cardiomyopathy (HC). To date, no diagnostic variables at baseline are available to predict long-term success of the procedure. We hypothesized that an immediate decrease in septal longitudinal strain after ASA would be associated with sustained LVOT gradient decrease after 6 months. ASA was performed in 22 patients with HC and severe drug-refractory symptoms. Clinical evaluation and 2-dimensional echocardiography were performed before, 1 day after, and 6 months after ASA. During 6-month follow-up, New York Heart Association class improved (2.7 +/- 0.5 vs 1.4 +/- 0.6, p <0.01) and LVOT gradient decreased (68 +/- 31 vs 21 +/- 21 mm Hg, p <0.01). Strain evaluation showed considerable decreases in basal septal strain (-12 +/- 3% vs -8 +/- 2%, p <0.01) and midseptal strain (-13 +/- 4% vs -8 +/- 3%, p <0.01) 1 day after ASA. Decreases in basal septal and midseptal strain 1 day after ASA were strongly related to the decrease in LVOT gradient during 6-month follow-up (r = 0.70, p <0.01, and r = 0.65, p <0.01, respectively). In conclusion, in patients with HC and severe drug-refractory symptoms, immediate decrease in septal strain after ASA is strongly related to a decrease in LVOT gradient after 6 months and might therefore serve as an early determinant for long-term success of the ASA procedure.

Interventional therapies for heart failure in the elderly

The aging of a population replete with risk factors for heart failure (HF) (coronary heart disease, diabetes, and hypertension) coupled with a declining age-adjusted mortality rate for coronary artery and hypertensive heart diseases has created, and will continue to create, a literal explosion in the prevalence of HF in the United States. Despite advances in maximal medical therapy, however, most patients who have symptomatic HF can expect functional impairment, interludes of worsening symptomatology, and a shortened lifespan. This article updates the use of interventional therapies for the treatment of elderly patients who have HF caused by coronary artery disease, valvular heart disease, congenital heart disease, myocardial disease, and renal vascular disease.

One-year follow-up of percutaneous septal ablation for symptomatic hypertrophic obstructive cardiomyopathy in 312 patients: predictors of hemodynamic and clinical response

AIM

The aim of this study was to analyze hemodynamic and clinical outcome in a cohort of 312 patients who were followed up over a period of 12 months after alcohol septal ablation (PTSMA) for symptomatic hypertrophic obstructive cardiomyopathy (HOCM).

METHODS AND RESULTS

PTSMA was intended in 337 patients with HOCM (mean age: 54+/-15 years), with 312 procedures completed by injection of 2.8+/-1.2 ml of alcohol. In 25 patients (8%) the intervention was aborted, mostly because of contrast echocardiographic findings. In the 312 patients who received alcohol, permanent pacing was necessary in 22 cases (7%); and in-hospital mortality was 1.3% (four patients). During follow-up, contact to six patients (2%) was lost, and three additional patients (1%) died. The 299 patients who either underwent non-invasive reassessment in our institution or transmitted followup data from their local physician formed the study population. Improvement in symptoms was reported by 272 patients (91%). Mean NYHA functional class was reduced from 2.9+/-0.4 to 1.5+/-0.7 (p<0.0001) along with a gradient reduction (echo-Doppler) from 59+/-32 to 8+/-15 mmHg at rest, and from 120+/-42 to 28+/-32 mmHg with provocation (p<0.0001 each). Exercise capacity improved from 94+/-51 to 119+/-40 watts (p=0.001), and peak oxygen consumption from 18+/-4 to 21+/-6 ml/ kg/min (p=0.01). Younger age and higher outflow gradients at baseline and immediately after intervention were associated with a less favorable hemodynamic outcome. The degree of limitation of exercise capacity at baseline was the only predictor of symptomatic improvement.

CONCLUSIONS

Catheter-based septal ablation is an effective non-surgical technique for reducing symptoms and outflow gradients in HOCM. In contrast to a previous study, in this cohort of 312 patients there was no association between post-interventional enzyme release and hemodynamic success. Younger patients with high baseline gradients, however, tended to have a less favorable hemodynamic outcome with higher residual gradients.

Interventional therapies for heart failure in the elderly

The aging of a population replete with risk factors for heart failure(HF) (coronary heart disease, diabetes, and hypertension) coupled with a declining age-adjusted mortality rate for coronary artery and hypertensive heart diseases has created, and will continue to create, a literal explosion in the prevalence of HF in the United States. Despite advances in maximal medical therapy, however, most patients who have symptomatic HF can expect functional impairment, interludes of worsening symptomatology, and a shortened lifespan. This article updates the use of interventional therapies for the treatment of elderly patients who have HF caused by coronary artery disease, valvular heart disease, congenital heart disease, myocardial disease, and renal vascular disease.

Noninvasive cardiac imaging in patients with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy and the most common cause of cardiac death in young athletes in the U.S. Noninvasive imaging plays an important role in detecting the disease, understanding its pathophysiology, and selecting as well as guiding appropriate therapy. In this review, we discuss the existing methodology with emphasis on current and emerging clinical applications in patients with HCM.

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.

Pathophysiology and Treatment of Hypertrophic Cardiomyopathy

All patients with hypertrophic cardiomyopathy (HCM) should have five aspects of care addressed. An attempt should be made to detect the presence or absence of risk factors for sudden arrhythmic death. If the patient appears to be at high risk, discussion of the benefits and risks of ICD are indicated, and many such patients will be implanted. Symptoms are appraised and treated. Bacterial endocarditis prophylaxis is recommended. Patients are advised to avoid athletic competition and extremes of physical exertion. First degree family members should be screened with echocardiography and ECG.

Intracardiac echocardiography guidance during percutaneous transluminal septal myocardial ablation in patients with obstructive hypertrophic cardiomyopathy

BACKGROUND

Percutaneous transluminal septal myocardial ablation (PTSMA) recently emerged as an alternative to myectomy for hypertrophic obstructive cardiomyopathy (HOCM) patients with drug-refractory symptoms. The target septal branch selection is a main point to achieve the therapeutic result.

METHODS AND RESULTS

We report about PTSMA performed using intracardiac echocardiography (ICE) to guide the procedure in 9 symptomatic HOCM patients. The target septal branch was chosen on the basis of the risk-area visualized using ICE after injection of a contrast agent. During alcohol administration a backscattered signal enhancement of the infarcted area was detected. The procedures were uncomplicated and effective to reduce the gradient from 78.9+/-20.4 mmHg to 7.8+/-7.9 mmHg (p<0.0001).

CONCLUSIONS

In this initial experience ICE monitoring during PTSMA was safe and provided high quality and continuous imaging of the treated segment of the septum during the whole procedure.

Catheter-based septal ablation for symptomatic hypertrophic obstructive cardiomyopathy: follow-up results of the TASH-registry of the German Cardiac Society

INTRODUCTION

In late 1997, the German Cardiac Society set up a multicenter registry to evaluate the acute and mid-term course of all patients (pts.) treated with septal ablation for symptomatic hypertrophic obstructive cardiomyopathy (HOCM). An analysis of the acute results has already been published. We now report on the mid-term course (3-6 months) of 242 pts. registered through September 1999.

RESULTS

Follow-up was 92% complete (n=222). During follow-up (mean: 4.9+/-2.3 months), an additional 3 pts. died (in-hospital mortality: 3 pts.). A satisfactory clinical effect was reported by 195 pts. (88%); 27 pts. (12%) remained in NYHA classes III and IV. Overall symptomatic improvement (NYHA class: from 2.8+/-0.7 to 1.7+/-0.7) paralleled the outflow gradient (LVOTG) reduction which was further accentuated as compared with the acute result (Doppler measurement at rest: from 57+/-31 to 25+/-25 mmHg to 20+/-21 mmHg; with provocation: from 107+/-53 to 49+/-40, to 44+/-40 mmHg, p<0.001, resp.). Left atrial (LA) diameter (from 46+/-8 to 44+/-7 mm) and septal thickness (from 20+/-5 to 15+/-5 mm; p<0.001, resp.) were also reduced. Comparing the methods for target vessel selection (i.e., with contrast echo monitoring vs pressurefluoroscopy guidance), at followup clinical improvement and hemodynamic measurements were comparable.

CONCLUSION

Clinical success can be achieved by septal ablation, both with the echocontrast guided and gradient-fluoroscopy guided method, in 88% of highly symptomatic HOCM pts. At mid-term follow-up, symptoms, left atrial size and septal thickness are reduced, and outflow gradients are further improved as compared to the acute result.

Percutaneous Versus Surgical Treatment for Patients With Hypertrophic Obstructive Cardiomyopathy and Enlarged Anterior Mitral Valve Leaflets

Background— The purpose of this study was to compare percutaneous transluminal septal myocardial ablation (PTSMA) and septal myectomy combined with mitral leaflet extension (MLE) in symptomatic hypertrophic obstructive cardiomyopathy patients with an enlarged anterior mitral valve leaflet (AMVL). Both PTSMA and myectomy reduce septal thickness and left ventricular outflow tract (LVOT) gradient; however, an uncorrected enlarged AMVL may predispose to residual systolic anterior motion (SAM) after successful standard myectomy or PTSMA. Myectomy with MLE previously demonstrated superior hemodynamic results compared with standard myectomy, but its value relative to PTSMA is unknown.

Methods and Results— Twenty-nine patients (aged 44±12 years) underwent myectomy with MLE, and 43 patients (aged 52±17 years) underwent PTSMA. Mitral leaflet area was similar in both groups (16.7±3.4 versus 15.9±2.7 cm 2 , respectively). After PTSMA, 2 patients died, 4 needed a reintervention, and 4 required a permanent pacemaker for complete heart block. After surgery, only 1 patient needed a reintervention. At 1-year follow-up, LVOT gradients did not differ between surgical and PTSMA patients (17±14 versus 23±19 mm Hg, respectively). Preinterventional mitral regurgitation grade was more severe in the surgical group, but with myectomy combined with MLE, the residual grade was similar to that of PTSMA. Mean SAM grade decreased significantly more after surgery (from 2.9±0.3 to 0.5±0.7 mm Hg versus from 2.8±0.5 to 1.3±0.9 mm Hg, P <0.05).

Conclusions— PTSMA in these selected patients with hypertrophic obstructive cardiomyopathy had more periprocedural complications and resulted in more reinterventions. Hemodynamic results (SAM grade and reduction in mitral regurgitation) were better in surgical patients.

Effects of Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy on Doppler Tei Index: A Midterm Follow-Up

Alcohol septal ablation (PTSMA) improves outflow gradient, left ventricular (LV) diastolic function, and symptoms in patients with hypertrophic obstructive cardiomyopathy (HOCM). Tei index (TI) is a Doppler parameter reflecting both systolic and diastolic LV function. Midterm changes of TI after PTSMA have not been determined up to now. Twenty-seven consecutive patients (mean age 53 +/- 13 years) with symptomatic HOCM underwent PTSMA procedure. Clinical and echocardiographic data were collected at baseline, 6 and 12 months after PTSMA. TI decreased from 0.67 +/- 0.11 to 0.55 +/- 0.06, isovolumic contractile time (ICT) decreased from 74 +/- 20 to 48 +/- 11 ms, isovolumic relaxation time decreased from 146 +/- 25 to 117 +/- 9 ms, and LV ejection time decreased from 330 +/- 42 to 298 +/- 13 ms. LV remodeling was determined by LV dimension increase from 46 +/- 6 to 48 +/- 6 mm and basal septum thickness reduction from 22 +/- 4 to 15 +/- 3 mm. LV ejection fraction decreased from 78 +/- 7 to 73 +/- 6% and maximal outflow gradient decreased from 69 +/- 44 to 15 +/- 11 mmHg. All changes were statistically significant (P <0.01). Symptomatic improvement was characterized by relief of dyspnea (2.5 +/- 0.7 versus 1.4 +/- 0.6 NYHA class; P <0.01) and angina pectoris (2.6 +/- 0.9 versus 0.7 +/- 0.7 CCS class; P <0.01). PTSMA is an effective method of therapy for HOCM. Shortening of TI suggests the improvement of LV myocardial performance in the midterm follow-up.

Technology Insight: transcoronary ablation of septal hypertrophy

Among patients with hypertrophic cardiomyopathy, 5-10% have outflow tract obstruction that results in symptoms refractory to medical therapy. Surgical myectomy has been the gold standard for treating these patients since the 1960s. In the past 10 years, however, alcohol septal ablation has emerged as an alternative procedure. There is growing evidence to indicate that this technique is comparable to surgical myectomy with respect to hemodynamic and functional improvement, although no randomized comparative studies exist to date. The procedure consists of injecting as mall volume of alcohol into a septal perforator under balloon occlusion,preferably after localization of the target septal branch by myocardial contrast echocardiography. Relief of the gradient is instantaneous in about 90% of patients, and further decreases might occur over time. Functional class, exercise capacity and quality of life have been shown to be improved during follow-up. The main risk of the technique is atrioventricular block, which occurs in about 10% of patients. Because of this side-effect and a steep learning curve, the technique should be performed only by experienced operators and on carefully selected patients.

Regional dyssynergy of the interventricular septum after septal artery occlusion in hypertrophic obstructive cardiomyopathy: use of quantitative Doppler tissue and strain rate imaging

We report the regional myocardial mechanics of the interventricular septum in a patient with hypertrophic obstructive cardiomyopathy undergoing therapeutic septal artery occlusion. Myocardial velocities improved across the entire septum; however, strain rate imaging showed the presence of severe regional dyssynergy.

Predictors of Outcome After Alcohol Septal Ablation Therapy in Patients With Hypertrophic Obstructive Cardiomyopathy

BACKGROUND

Alcohol septal ablation (ASA) therapy results in clinical and hemodynamic improvement in patients with hypertrophic obstructive cardiomyopathy. However, a subset remains symptomatic afterward, requiring additional procedures. We sought to examine the determinants of an unsatisfactory outcome, defined as unchanged symptoms with <50% reduction of baseline left ventricular outflow tract (LVOT) gradient.

METHODS AND RESULTS

Of 173 consecutive hypertrophic obstructive cardiomyopathy patients who underwent ASA, 39 had an unsatisfactory outcome after the first procedure. Patients with an unsatisfactory outcome had a higher baseline LVOT gradient, fewer septal arteries injected with ethanol, lower peak creatine kinase (CK), smaller septal area opacified by contrast echocardiography, and higher residual gradient in the catheterization laboratory after ASA (all P<0.05). Symptoms, septal thickness, mitral regurgitation severity, and ventricular function were not determinants of outcome. On multiple logistic regression, LVOT gradient reduction after ASA in the catheterization laboratory to > or =25 mm Hg (OR, 5.5; P=0.01) and peak CK <1300 U/L (OR, 2.5; P=0.04) were the independent predictors of an unsatisfactory outcome.

CONCLUSIONS

The residual LVOT gradient in the catheterization laboratory and peak CK leak after ASA are the independent predictors of ASA outcome.