Nonsurgical septal reduction for hypertrophic obstructive cardiomyopathy: outcome in the first series of patients

Invasive Management of Hypertrophic Cardiomyopathy With Clinically Important Obstruction: Catheter Intervention Is Superior

Hypertrophic cardiomyopathy is a common inherited cardiac condition where the myocardium progressively thickens in the absence of abnormal loading conditions. Left ventricular hypertrophy often leads to outflow tract obstruction, and this confers significant mortality and morbidity implications. Septal reduction therapies aim to relieve the obstruction in an attempt to reduce the burden of symptoms and potentially improve prognosis. However, both surgical and catheter-based approaches to septal reduction carry risks. At present, international guidelines and expert consensus statements suggest surgical myomectomy is the gold-standard treatment. In this point-counterpoint review, we discuss why in our opinion this recommendation should be reconsidered. We hope to cover the history of catheter based septal reduction therapies and the significant advances made over the last two decades. We also hope to show why we believe the current evidence shows catheter-based alcohol septal ablation is superior to surgical myomectomy.

Exercise Capacity in Patients With Obstructive Hypertrophic Cardiomyopathy: SEQUOIA-HCM Baseline Characteristics and Study Design

Patients with obstructive hypertrophic cardiomyopathy (oHCM) have increased risk of arrhythmia, stroke, heart failure, and sudden death. Contemporary management of oHCM has decreased annual hospitalization and mortality rates, yet patients have worsening health-related quality of life due to impaired exercise capacity and persistent residual symptoms. Here we consider the design of clinical trials evaluating potential oHCM therapies in the context of SEQUOIA-HCM (Safety, Efficacy, and Quantitative Understanding of Obstruction Impact of Aficamten in HCM). This large, phase 3 trial is now fully enrolled (N = 282). Baseline characteristics reflect an ethnically diverse population with characteristics typical of patients encountered clinically with substantial functional and symptom burden. The study will assess the effect of aficamten vs placebo, in addition to standard-of-care medications, on functional capacity and symptoms over 24 weeks. Future clinical trials could model the approach in SEQUOIA-HCM to evaluate the effect of potential therapies on the burden of oHCM. (Safety, Efficacy, and Quantitative Understanding of Obstruction Impact of Aficamten in HCM [SEQUOIA-HCM]; NCT05186818).

Unexpected suicide left ventricle post-surgical aortic valve replacement requiring veno-arterial extracorporeal membrane oxygenation support despite gold-standard therapy: a case report

Background

Suicide left ventricle is a well-documented phenomenon occurring after valve replacement, however, it is most commonly described in the mitral valve replacement (MVR) and transcatheter aortic valve replacement (TAVR) population. Cases within the surgical aortic valve replacement (SAVR) population usually resolve with optimal medical and interventional therapies. We describe a case of left ventricular suicide following SAVR presenting with persistent haemodynamic instability despite currently accepted medical and surgical therapies.

Case summary

A 62-year-old male with severe aortic stenosis presented for SAVR and a MAZE procedure. There were no significant signs of ventricular hypertrophy on preoperative transthoracic echocardiogram (TTE). Intraoperatively, there was mild chordal systolic anterior motion of the mitral valve (SAM) which only occurred when underfilled. During recovery in the intensive care unit, the patient’s pulmonary arterial pressures were noted to rise with worsening cardiac output. Subsequent TTE showed severe dynamic left ventricular outflow tract (LVOT) obstruction secondary to SAM. Due to refractory medical management, an alcohol septal ablation was performed. Despite resolution of obstruction, the patient exhibited biochemical signs of systemic hypoperfusion, and thus veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support was initiated. Following 72 h of VA-ECMO support, the patient was weaned with complete resolution of biochemical insults. He was subsequently discharged from the hospital without complication.

Discussion

Compared to the TAVR population, suicide ventricle post-SAVR is comparatively rare. Patients who exhibit persistent impaired cardiac output postoperatively should be investigated rapidly with echocardiography. Furthermore, resolution of a LVOT obstruction state from procedural intervention may not immediately follow with improved cardiac output, and may require further supportive management.

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.

Predicting complete heart block after alcohol septal ablation for hypertrophic cardiomyopathy using a risk stratification model and clinical tool

BACKGROUND

Alcohol septal ablation (ASA) is a proven method of septal reduction for patients with drug refractory, symptomatic hypertrophic obstructive cardiomyopathy (HOCM). This procedure is associated with a 6.5-11% risk of complete heart block (CHB).

OBJECTIVE

The aim of this study is to determine factors that predict CHB and to develop a clinical tool for risk stratification of patients.

METHODS

Patients were enrolled into an ongoing ASA study. A total of 636 patient procedures were included, 527 of whom were used in the development of the prediction tool, and 109 of whom were used for independent validation. Multivariate analysis was performed with odds ratios used to develop the clinical prediction tool. This was then internally and externally validated.

RESULTS

Of the 527 in the prediction cohort, 46 developed CHB. The predictors of CHB were age ≥50 years, pre-ASA left bundle branch block (LBBB), transient procedural high-grade block, post-ASA PR prolongation ≥68 ms, and new bifascicular block. An 11-point clinical prediction tool was developed to classify these factors. Internal validation using a receiver operating characteristic curve revealed an area under the curve of 0.88 for the clinical prediction tool. External validation using 109 contemporary patients revealed a 98% negative predictive value, 24% positive predictive value, 75% sensitivity, and 81% specificity in high-risk patients.

CONCLUSION

Among patients undergoing ASA, the risk of CHB can be predicted with easily obtained clinical and electrocardiographic factors. This clinical prediction tool allows identification of high-risk patients who may benefit from additional monitoring and therapy.

Alcohol dose in septal ablation for hypertrophic obstructive cardiomyopathy

BACKGROUND

The aim of this study was to evaluate short- and long-term outcomes related to dose of alcohol administered during alcohol septal ablation (ASA) in patients with hypertrophic obstructive cardiomyopathy (HOCM). Current guidelines recommend using 1-3 mL of alcohol administered in the target septal perforator artery, but this recommendation is based more on practical experience of interventionalists rather than on systematic evidence.

METHODS

We included 1448 patients and used propensity score to match patients who received a low-dose (1.0-1.9 mL) versus a high-dose (2.0-3.8 mL) of alcohol during ASA.

RESULTS

The matched cohort analysis comprised 770 patients (n = 385 in both groups). There was a similar occurrence of 30-day post-procedural adverse events (13% vs. 12%; p = 0.59), and similar all-cause mortality rates (0.8% vs. 0.5%; p = 1) in the low-dose group and the high-dose group, respectively. In the long-term follow-up (5.4 ± 4.5 years), a total of 110 (14%) patients died representing 2.58 deaths and 2.64 deaths per 100 patient-years in the low dose and the high dose group (logrank, p = 0.92), respectively. There were no significant differences in the long-term dyspnea and left ventricular outflow gradient between the two groups. Patients treated with a low-dose of alcohol underwent more subsequent septal reduction procedures (logrank, p = 0.04).

CONCLUSIONS

Matched HOCM patients undergoing ASA with a low-dose (1.0-1.9 mL) or a high-dose (2.0-3.8 mL) of alcohol had similar short- and long-term outcomes. A higher rate of repeated septal reduction procedures was observed in the group treated with a low-dose of alcohol.

An unusual complication during alcohol septal ablation: severe left anterior descending artery vasospasm causing cardiac arrest: a case report and review of the literature

Background

Septal reduction therapy can be considered along the lines of hypertrophic obstructive cardiomyopathy patients who have drug-refractory symptoms. This can be applied either surgical myectomy or either alcohol septal ablation (ASA). Alcohol septal ablation has been performed successfully since the first announcement of ASA in 1995.

Case summary

We present a case report of coronary artery vasospasm that occurred in the left anterior descending artery (LAD) during ASA. We performed ASA via first septal artery. Two cubic centimetre of 99% ethanol was slowly injected and 10 min later balloon was withdrawn. Then the patient felt severe chest pain; his systolic blood pressure went down quickly and fibrillated. We started the cardiopulmonary resuscitation (CPR). After CPR, the rhythm was achieved total 4 min later cardiac arrest but blood pressure was low. Emergent coronary angiography showed that coronary spasm caused severe occlusion in the LAD segment just after the first septal artery and impaired coronary flow nearly totally in the LAD just after septal artery. At that time, we decided to implant a stent due to the patient’s serious condition and a 3.5 × 18 mm drug-eluting stent was implanted. We performed control angiography to patient 3 days later of the procedure and LAD flow was TIMI 3.

Discussion

The causes of LAD occlusion are alcohol leakage, dissection, and vasospasm. It is important to detect the correct reason for appropriate treatment. Alcohol leakage impairs and causes coronary flow disruption; this can cause ventricular wall motion abnormalities. In our case, there was severe spasm in the LAD coronary artery and LAD flow was severely impaired. On echocardiogram, there was no myocardial wall motion abnormality. So alcohol leakage was ruled out. Left anterior descending artery image was not typical dissection. As a result of these findings, we concluded that the cause of LAD occlusion was coronary artery vasospasm.

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

INTRODUCTION

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

CONCLUSIONS

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

Elevated Cardiac Enzymes in Hypertrophic Cardiomyopathy Patients With Heart Failure - A 20-Year Prospective Follow-up Study

BACKGROUND

To better understand the evolution of typical hypertrophic cardiomyopathy (HCM) to heart failure (HF), we investigated the relationship between serum biochemical abnormalities and changes in left ventricular (LV) remodeling.

METHODS AND RESULTS

Seventy-seven HCM patients were followed for 20 years. Creatine kinase (CK), CK-MB, lactate dehydrogenase (LDH), LDH-1, troponin T and myosin light chain-1 (MLC-1) were measured. Abnormal CK-MB elevation was observed in 64% of HCM patients. LDH-1 was not significantly different compared with the control subjects. Troponin T elevation was observed in 3 HCM patients and MLC-1 elevation was not observed. According to median CK-MB, HCM patients were divided into 2 groups: group H (CK-MB ≥2.5%, n=33) and group L (CK-MB <2.5%, n=44). During the follow-up period in group H, LV end-diastolic dimension increased (P<0.0001), fractional shortening decreased (P<0.0004), and left atrial dimension increased (P<0.0001). The markers reflecting LV hypertrophy were significantly decreased. In group L, LV end-diastolic dimension increased (P<0.02) and left atrial dimension increased (P<0.0001). HF was observed in 18 patients in group H and in 4 in group L. There were 14 HF deaths in group H and 2 in group L, and 3 sudden cardiac deaths in group H.

CONCLUSIONS

Persistent elevation of cardiac enzymes in HCM patients indicates ongoing myocardial injury, ultimately resulting in death by HF.

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

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

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.

Cardiac MRI detected septal and lateral myocardial infarction by alcohol septal ablation through the intermediate artery

A 65-year-old woman with hypertrophic obstructive cardiomyopathy presented with dyspnea. Transthoracic echocardiography showed severe mitral regurgitation (MR) due to systolic anterior motion and a peak gradient of 102 mmHg across the LV outflow. Cardiac magnetic resonance imaging (CMR) showed patchy late gadolinium enhancement in the hypertrophied septum. Because of non-responsiveness to medical treatment, percutaneous alcohol septal ablation (ASA) was conducted. The septal perforator that supplied the hypertrophic myocardium originated from the intermediate artery. A 2.0-mm over-the-wire balloon was used to occlude the intermediate artery and 1.1 ml of ethanol was injected slowly into the target septal perforator branch. The gradient decreased markedly to 5 mmHg immediately after ASA, and electrocardiogram showed right bundle branch block. Echocardiographic findings at 1 week were satisfactory. However, CMR showed delayed enhancement in both the hypertrophic basal septum and the lateral wall. The clinical course was uneventful, and she has maintained NHYA functional class 1 so far. In this case, proximal migration of the balloon or an undersized occluding balloon may have caused lateral infarction through leakage of ethanol into another branch. CMR is a useful modality to verify whether the ASA procedure has induced the appropriate controlled infarction.

Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy is a fascinating disease of marked heterogeneity. Hypertrophic cardiomyopathy was originally characterized by massive myocardial hypertrophy in the absence of known etiology, a dynamic left ventricular outflow obstruction, and increased risk of sudden death. It is now well accepted that multiple mutations in genes encoding for the cardiac sarcomere are responsible for the disease. Complex morphologic and pathophysiologic differences, disparate natural history studies, and novel treatment strategies underscore the challenge to the practicing cardiologist when faced with the management of the hypertrophic cardiomyopathy patient.

Interventional treatments for hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disorder. This autosomal dominant condition is defined by left ventricular hypertrophy and associated with functional limitation and premature death. In fact, many individuals are asymptomatic and the annual mortality in most modern series is 1% or less. However, severe symptoms may develop at any age, and the risk of premature death from arrhythmia, stroke, and progressive systolic impairment may complicate asymptomatic disease. The clinical management of patients with HCM therefore encompasses (1) genetic counseling including discussion of indications for genetic testing and cascade family screening, (2) assessment of prognostic risk from ventricular arrhythmia, stroke, and heart failure, and (3) symptom management. This article describes the interventional treatments in the management of severe symptoms associated with left ventricular outflow tract obstruction (LVOTO).

Is multidetector computed tomography a suitable alternative to MR imaging for the assessment of myocardial necrosis after alcohol septal ablation?

BACKGROUND

To compare magnetic resonance (MR) imaging and multidetector computed tomography (MDCT) for the assessment of myocardial infarction (MI) after alcohol septal ablation (ASA).

METHODS

Ten patients (mean age, 60 years ± 16) were examined with both MDCT and 1.5-T MR imaging performed 10 minutes after injection, within 3 days after ASA. Half of them had a temporary pacemaker (PM) during MDCT examination. Global image quality (IQ) and localization of MI were noticed on both MDCT and MR images. Volumes of MI, contrast-to-noise ratios (CNR) and signal-to-noise ratios (SNR) were also calculated. ASA effectiveness was evaluated by echocardiography immediately and 3 months after procedure.

RESULTS

Global IQ was considered adequate for both procedures. In 8 patients, MI reached the basal part of the septum on both MDCT and MR images. The 2 remaining patients exhibited sparing of the basal septum on MDCT and MR images. Volumes of MI were within the same range with the 2 techniques (MDCT: 22.1 ± 8.8 mL; MR imaging: 23.8 ± 9.4 mL) and correlated well each other (R(2)=0.85, p<0.002). The 2 patients with sparing of the basal interventricular septum had persistent gradient on echocardiography 3 months after ASA, suggesting failure of the procedure. The volumes of MI didn't correlate with the reduction of pressure gradient on echocardiography 3 months after ASA (R(2)=0.02, p<0.05).

CONCLUSIONS

Evaluation of post ASA MI is feasible with MDCT by comparison with MR imaging. MDCT might serve as an alternative imaging method in case of PM implantation.

Cardiomyopathies (hypertrophy and failure): what can offer cardiac magnetic resonance imaging?

In routine, cardiomyopathy, confirmed or not, is a frequent reason for cardiac MRI evaluation. Step by step, by using a wide panel of sequences, cardiac MRI is able to characterize cardiomyopathies by their morphologic and functional phenotype as well as by tissue characterization. Cardiac-MRI is also considered as the most appropriate technique for the follow-up of this disease. The purpose of this article is to browse an overview of the main MRI features of cardiomyopathy, focusing the purpose on hypertrophic forms and myocardial diseases leading to cardiac failure.

A pipeline that integrates the discovery and verification of plasma protein biomarkers reveals candidate markers for cardiovascular disease

We developed a pipeline to integrate the proteomic technologies used from the discovery to the verification stages of plasma biomarker identification and applied it to identify early biomarkers of cardiac injury from the blood of patients undergoing a therapeutic, planned myocardial infarction (PMI) for treatment of hypertrophic cardiomyopathy. Sampling of blood directly from patient hearts before, during and after controlled myocardial injury ensured enrichment for candidate biomarkers and allowed patients to serve as their own biological controls. LC-MS/MS analyses detected 121 highly differentially expressed proteins, including previously credentialed markers of cardiovascular disease and >100 novel candidate biomarkers for myocardial infarction (MI). Accurate inclusion mass screening (AIMS) qualified a subset of the candidates based on highly specific, targeted detection in peripheral plasma, including some markers unlikely to have been identified without this step. Analyses of peripheral plasma from controls and patients with PMI or spontaneous MI by quantitative multiple reaction monitoring mass spectrometry or immunoassays suggest that the candidate biomarkers may be specific to MI. This study demonstrates that modern proteomic technologies, when coherently integrated, can yield novel cardiovascular biomarkers meriting further evaluation in large, heterogeneous cohorts.

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.

Left ventricular longitudinal systolic function after alcohol septal ablation for hypertrophic obstructive cardiomyopathy: a long-term follow-up study focused on speckle tracking echocardiography

AIMS

To examine left ventricular (LV) longitudinal systolic myocardial function in patients with hypertrophic obstructive cardiomyopathy (HOCM) before and after transcoronary ablation of septal hypertrophy (TASH).

METHODS AND RESULTS

Twenty-three of 39 consecutive patients with HOCM had serial two-dimensional (2D) echocardiograms available for speckle tracking analyses before and up to 36 months after TASH. Before TASH, overall LV myocardial longitudinal systolic 2D strain was decreased despite normal LV ejection fraction (EF). A significant reduction of LV mass and left ventricular outflow tract (LVOT) gradients occurred during long-term follow-up after TASH, but this was not accompanied by improvement of average LV longitudinal systolic strain. However, in the basal LV segments remote to the site of alcohol injection longitudinal systolic strain increased [baseline: -13.1 ± 5.4%; 1 month: -16.0 ± 5.5% (NS); 12 months: -16.5 ± 4.9% (P < 0.05 vs. baseline); 36 months: -17.4 ± 4.2% (P < 0.01 vs. baseline)]. In contrast, the alcohol-treated basal segments of the septum and adjacent myocardium showed unchanged strain over time.

CONCLUSION

Average LV longitudinal myocardial systolic function is depressed in HOCM despite normal LV EF. TASH-induced reduction of the LVOT obstruction does not improve average LV longitudinal systolic 2D strain. This is in contrast to global improvement of longitudinal systolic function after valve replacement in aortic valve stenosis. The discrepancy may be caused by the fact that HOCM is a primary myocardial disease.

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.

Coronary Morphology and Conduction System Disturbance Induced by Therapeutic Embolization of the Coronary Septal Artery

Background: Percutaneous transluminal septal myocardial alcohol ablation (PTSMAA) is not a procedure without complications. It may produce heart arrhythmias, especially those due to disturbances of atrioventricular (AV) and interventricular (IV) electrical conduction.Objective: The goal of this study was to evaluate the relationship between the anatomical patterns of the right coronary artery and the left anterior descending artery (LAD) and to relate them to the AV and IV bundle branch blocks provoked by PTSMAA.Method: Twenty patients with obstructive hypertrophic cardiomyopathy resistant to treatment with drugs successfully underwent PTSMAA. Electrocardiographic analyses were done before and after PTSMAA, and the results were compared with the abnormal septal anatomy.Results: The effectiveness of PTSMAA was obtained in 18 (90%) of the 20 patients by ethanolization of the first great septal branch. In the other 2 patients (10%), 2 septal branches underwent alcoholization. First-grade temporary AV block (AVB) was observed in 6 patients (30%). Ten patients experienced severe bradycardia due to total AVB that required a temporary pacemaker, but 3 of the patients (15%) required a permanent pacemaker. Fourteen patients (70%) experienced permanent complete right branch block, and 2 developed incomplete left anterior block and incomplete left posterior block. Six patients presented with no electrical conduction disturbance at all.Conclusion: According to the results of the present investigation with the AV node artery derived from the right coronary artery in all cases, complete and permanent AV conduction system blockade occurred after PTSMAA in all types of anatomy regarding the observed LAD.

Retrograde ethanol infusion in the vein of Marshall: regional left atrial ablation, vagal denervation and feasibility in humans

BACKGROUND

The vein of Marshall (VOM) is an attractive target during ablation of atrial fibrillation due to its autonomic innervation, its location anterior to the left pulmonary veins and drainage in the coronary sinus.

METHODS AND RESULTS

We studied 17 dogs. A coronary sinus venogram showed a VOM in 13, which was successfully cannulated with an angioplasty wire and balloon. In 5 dogs, electroanatomical maps of the left atrium were performed at baseline and after ethanol infusion in the VOM, which demonstrated a new crescent-shaped scar, extending from the annular left atrium towards the posterior wall and left pulmonary veins. In 4 other dogs, effective refractory periods (ERP) were measured at 3 sites in the left atrium, before and after high-frequency bilateral vagal stimulation. The ERP decreased from 113.6+/-35.0 ms to 82.2+/-25.4 ms (p<0.05) after vagal stimulation. After VOM ethanol infusion, vagally-mediated ERP decrease was eliminated (from 108.6+/-24.1 ms to 96.4 +/-16.9ms, p=NS). The abolition of vagal effects was limited to sites near the VOM (ERP: 104+/-14 ms, vs 98.6+/-12.2 ms post vagal stimulation, p=ns), as opposed to sites remote to VOM (ERP: 107.2+/-14.9 ms, vs 78.6+/-14.7ms post vagal stimulation, p<0.05). To test feasibility in humans, 5 patients undergoing pulmonary vein antral isolation had successful VOM cannulation and ethanol infusion: left atrial voltage maps demonstrated new scar involving the infero-posterior left atrial wall extending towards the left pulmonary veins.

CONCLUSIONS

Ethanol infusion in then VOM achieves significant left atrial tissue ablation, abolishes local vagal responses and is feasible in humans.

Therapeutic strategies for diastolic dysfunction: a clinical perspective

Diastolic dysfunction, which is increasingly viewed as being influential in precipitating heart failure and determining prognosis, is often unrecognized and has therapeutic implications distinct from those that occur with systolic dysfunction. In this review, several therapeutic modalities including pharmacologic, nonpharmacologic, and surgical approaches for primary diastolic dysfunction and heart failure will be discussed.

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.

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.

Developing multiplexed assays for troponin I and interleukin-33 in plasma by peptide immunoaffinity enrichment and targeted mass spectrometry

BACKGROUND

Protein biomarker candidates from discovery proteomics must be quantitatively verified in patient samples before they can progress to clinical validation. Here we demonstrate that peptide immunoaffinity enrichment coupled with stable isotope dilution mass spectrometry (SISCAPA-MRM) can be used to configure assays with performance suitable for candidate biomarker verification. As proof of principle, we configured SISCAPA assays for troponin I (cTnI), an established biomarker of cardiac injury, and interleukin 33 (IL-33), an emerging immunological and cardiovascular marker for which robust immunoassays are currently not available.

METHODS

We configured individual and multiplexed assays in which peptides were enriched from digested human plasma using antipeptide antibodies. Assay performance was established using response curves for peptides and proteins spiked into normal plasma. We quantified proteins using labeled peptides as internal standards, and we measured levels of cTnI in patients who underwent a planned myocardial infarction for hypertrophic obstructive cardiomyopathy.

RESULTS

Measurement of cTnI and IL-33 proteins from trypsin-digested plasma was linear from 1.5 to 5000 microg/L, with imprecision <13% for both proteins, processed individually or multiplexed. Results correlated well (R = 0.89) with a commercial immunoassay.

CONCLUSIONS

We used an established biomarker of cardiac injury and an emerging biomarker to demonstrate how SISCAPA can detect and quantify changes in concentration of proteins present at 1-10 microg/L in plasma. Our results demonstrate that these assays can be multiplexed and retain the necessary precision, reproducibility, and sensitivity to be applied to new and uncharacterized candidate biomarkers for verification of low-abundance proteins in blood.

Implantable cardioverter-defibrillator therapy for primary prevention of sudden death after alcohol septal ablation of hypertrophic cardiomyopathy

OBJECTIVES

The purpose of this study was to examine the effects of alcohol septal ablation (ASA) on ventricular arrhythmias among patients with obstructive hypertrophic cardiomyopathy (HCM), as measured by appropriate implantable cardioverter-defibrillator (ICD) discharges.

BACKGROUND

Alcohol septal ablation is an effective therapy for patients with symptomatic HCM. However, concern has been raised that ASA may be proarrhythmic secondary to the iatrogenic scar created during the procedure. The impact of ASA on ventricular arrhythmias has not been well described.

METHODS

This prospective study included 123 consecutive patients with obstructive HCM who underwent ASA and had an ICD implanted for primary prevention of sudden cardiac death (SCD). The ICDs were implanted based on commonly accepted risk factors for SCD in the HCM population. Data from ICD interrogations during routine follow-up were collected.

RESULTS

Nine appropriate ICD shocks were recorded over a mean follow-up of 2.9 years in the cohort, which had a mean of 1.5 +/- 0.9 risk factors for SCD. Using Kaplan-Meier survival analysis, the estimated annual event rate was 2.8% over 3-year follow-up. There were no significant differences in the incidence of risk factors between patients who did and did not receive appropriate shocks.

CONCLUSIONS

The annual rate of appropriate ICD discharges after ASA is low and less than that reported previously for primary prevention of SCD in HCM. This suggests that ASA is not proarrhythmic. Traditional SCD risk factors did not predict ICD shocks in this cohort.

Metabolite profiling of blood from individuals undergoing planned myocardial infarction reveals early markers of myocardial injury

Emerging metabolomic tools have created the opportunity to establish metabolic signatures of myocardial injury. We applied a mass spectrometry-based metabolite profiling platform to 36 patients undergoing alcohol septal ablation treatment for hypertrophic obstructive cardiomyopathy, a human model of planned myocardial infarction (PMI). Serial blood samples were obtained before and at various intervals after PMI, with patients undergoing elective diagnostic coronary angiography and patients with spontaneous myocardial infarction (SMI) serving as negative and positive controls, respectively. We identified changes in circulating levels of metabolites participating in pyrimidine metabolism, the tricarboxylic acid cycle and its upstream contributors, and the pentose phosphate pathway. Alterations in levels of multiple metabolites were detected as early as 10 minutes after PMI in an initial derivation group and were validated in a second, independent group of PMI patients. A PMI-derived metabolic signature consisting of aconitic acid, hypoxanthine, trimethylamine N-oxide, and threonine differentiated patients with SMI from those undergoing diagnostic coronary angiography with high accuracy, and coronary sinus sampling distinguished cardiac-derived from peripheral metabolic changes. Our results identify a role for metabolic profiling in the early detection of myocardial injury and suggest that similar approaches may be used for detection or prediction of other disease states.

Hypertrophic cardiomyopathy: etiology, diagnosis, and treatment

Hypertrophic cardiomyopathy (HCM) is a disease characterized by primary hypertrophy of the left (and sometimes right) ventricle. The clinical manifestations of the disease are dyspnea, angina, and a continuum encompassing lightheadedness, presyncope, syncope, and sudden death. Although HCM is often caused by an identifiable mutation in a gene coding for a sarcomeric protein and inherited in an autosomal-dominant pattern, many patients do not have any relatives in whom the disease is manifest. The prevalence of HCM is estimated to be 0.2%, with nearly 600,000 Americans affected. This limited exposure of clinicians to HCM understandably accounts for the uncertainty that prevails regarding this disease and its management.

Frequency and mechanism of persistent systolic anterior motion and mitral regurgitation after septal ablation in obstructive hypertrophic cardiomyopathy

Relief of obstruction using ventricular septal ablation (VSA) may not eliminate systolic anterior motion (SAM) of the mitral valve and mitral regurgitation (MR) in patients with obstructive hypertrophic cardiomyopathy. The hypothesis was that persistent SAM after VSA was secondary to anterior papillary muscle displacement and malcoaptation of mitral valve leaflets and that these findings could predict persistence of SAM. Echocardiograms were examined from 37 patients with obstructive hypertrophic cardiomyopathy before and 12+/-3 months after VSA. Anterior leaflet malposition (anterior-to-posterior leaflet coaptation position ratio), papillary muscle malposition (septal-to-lateral/left ventricular internal diameter ratio), and anterior position of coaptation relative to the septum (coaptation-to-septal distance) were assessed. MR proximal jet width was also measured. Of 37 patients, 30 underwent successful VSA (left ventricular outflow tract gradient reduction>50%); 22 of 30 and 7 of 7 with <50% reduction (total 29 of 37; 78%) showed persistent SAM at 12+/-3 months. These patients had more anterior malposition of the mitral valve and less MR reduction than those without SAM: anterior-to-posterior leaflet coaptation position ratio 0.42+/-0.06 versus 0.56+/-0.09, septal-to-lateral/left ventricular internal diameter ratio 0.39+/-0.12 versus 0.55+/-0.12, coaptation-to-septal distance 1.8+/-0.42 versus 2.8+/-0.30 cm, and MR reduction by 29+/-22% versus 71+/-12% (p<0.0001). Gradients, both at rest and provokable, were higher (27+/-33 vs 4+/-5 mm Hg, p=0.0004; >45 mm Hg in 9 vs 0, p=0.03, respectively) in patients with persistent SAM. Anterior malposition was present before VSA, with anterior-to-posterior leaflet coaptation position ratio<0.5 predicting SAM after VSA (p<0.0001). In conclusion, SAM and MR were often not eliminated using VSA. Mitral valve malposition was a strong predictor of SAM and MR reduction after VSA and may need to be considered in optimizing results of this procedure.

Long-term follow-up after percutaneous septal ablation in hypertrophic obstructive cardiomyopathy

OBJECTIVES

The aim of this study was to evaluate the longterm follow-up results of percutaneous transluminal septal myocardial ablation (PTSMA) in a large patient cohort.

BACKGROUND

PTSMA by alcohol injection into septal branches has shown good acute and short-term results in symptomatic patients with hypertrophic obstructive cardiomyopathy.

METHODS

A total of 100 consecutive symptomatic (NYHA class 2.8 +/- 0.6) patients underwent PTSMA. All patients had clinical and non-invasive follow-up at 3 months, 1 year, and annually up to 8 years.

RESULTS

One patient died at day 2 after intervention due to fulminant pulmonary embolism following deep venous thrombosis, and eight patients required a permanent DDD-pacemaker due to post-interventional complete heart block. Acute reduction of the left ventricular outflow tract gradient was achieved from 76 +/- 37 to 19 +/- 21 mmHg at rest, from 104 +/- 34 to 43 +/- 31 mmHg during Valsalva maneuver, and from 146 +/- 45 to 59 +/- 42 mmHg post extrasystole (p < 0.0001, each). During follow-up (mean follow-up time: 58 +/- 14 months), three additional patients died (sudden death at 48 months, non-cardiac death at 49 months and stroke-related death at 60 months after the index procedure). All living patients showed clinical improvement to NYHA-class 1.4 +/- 0.6 (after 3 months, n = 99), 1.5 +/- 0.6 (after 1 year, n = 99), and 1.6 +/- 0.7 at final follow-up (n = 96; p < 0.0001, each). Non-invasive follow-up studies documented ongoing outflow tract gradient reduction, decrease of septal and left ventricular posterior wall thickness, and improvement of exercise capacity.

CONCLUSIONS

PTSMA is an effective treatment for symptomatic patients with hypertrophic obstructive cardiomyopathy. Follow-up showed ongoing hemodynamic and clinical improvement without increased mortality and morbidity.

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.

Percutaneous septal ablation for symptomatic hypertrophic obstructive cardiomyopathy: managing the risk of procedure-related AV conduction disturbances

AIM

To provide tools for predicting the course of AV conduction disturbances after ethanol-induced septal ablation (PTSMA) for hypertrophic obstructive cardiomyopathy (HOCM).

METHODS AND RESULTS

Based on a scoring system developed 1996-1998 and including parameters from baseline ECG, heart rate profile, severity of outflow obstruction (LVOTO), peri-interventional enzyme kinetics, and peri-interventional conduction problems, the risk of permanent AV block following PTSMA was assessed in 155 consecutive HOCM patients (pts.; mean age: 53+/-13 years) between 1999 and 2004. During PTSMA with 2.1+/-0.5 ml of ethanol, transient complete AV block occurred in 71 pts. (46%). Pts. were grouped into a low, intermediate, and high risk group for permanent conduction damage, and treated accordingly (early discharge from monitoring, prolonged monitoring, early DDD-PM implantation). Permanent pacing was necessary in 11 cases (7%), 0/116 of these (0%) in the low, 4/31 (13%) in the intermediate, and 7/8 (87%) in the high-risk group. While a new right bundle branch block was the most frequent ECG finding after PTSMA, a left bundle branch block at baseline was associated with 4 of the 11 DDD-PM implantations (p<0.0001). In-hospital mortality was 0%, short-term (3-months) follow up was complete. During follow-up, AV conduction recovered in 4 pts. (46%) with a DDD-PM. New onset AV blocks did not occur. Significant improvement of symptoms was reported by 141 pts. (91%).

CONCLUSIONS

Catheter-based septal ablation is an effective non-surgical technique for reducing symptoms and outflow gradients in HOCM. The proposed scoring system appears to reliably discriminate pts. with a high risk for permanent PM dependency from those with stable AV conduction after PTSMA. Pts. with left bundle branch block at baseline should undergo DDD-PM implantation prior to ablation.

New approach to septal ablation: glue (cyanoacrylate) septal ablation

Alcohol septal ablation is an alternative way of treatment in hypertrophic obstructive cardiomyopathy patients who are refractory to medical treatment. This case report describes a new way of septal ablation with glue (cyanoacrylate) in a HOCM patient who has extensive collateral to posterior descending coronary artery which precludes alcohol ablation.

Predictors of Complete Heart Block After Alcohol Septal Ablation for Hypertrophic Cardiomyopathy and the Timing of Pacemaker Implantation

Catheter-based alcohol septal ablation has recently been introduced for the treatment of left ventricular outflow tract obstruction in hypertrophic obstructive cardiomyopathy. It is associated with various conduction disturbances and may lead to transient or persistent complete heart block (CHB). Electrocardiographic (ECG) changes and predictors of developing CHB and the timing of permanent pacemaker implantation have been variable among the different studies. Among 50 patients studied, we found that a new right bundle branch pattern was the most common new ECG change after septal ablation and that baseline left bundle branch block was strongly associated with the development of CHB (P = 0.004); 9 patients (18%) required permanent pacemaker implantation of whom 7 (78%) remained pacemaker dependent at 14 days with no delayed recovery of atrioventricular conduction. This favors an early pacemaker implantation strategy.