Apical myectomy: A new surgical technique for management of severely symptomatic patients with apical hypertrophic cardiomyopathy

Outcomes of concomitant myectomy and left ventricular apical aneurysm repair in patients with hypertrophic cardiomyopathy

OBJECTIVES

Hypertrophic cardiomyopathy with left ventricular apical aneurysm is a phenotype associated with a 4-fold increase in the risk for sudden cardiac death. In this study, we describe the surgical outcome of concomitant apical aneurysm repair in patients undergoing transapical myectomy for hypertrophic cardiomyopathy.

METHODS

We identified 67 patients with left ventricular apical aneurysms who underwent transapical myectomy and apical aneurysm repair between July 2000 and August 2020. Long-term survival was compared with that of 2746 consecutive patients undergoing transaortic septal myectomy for obstructive hypertrophic cardiomyopathy with subaortic obstruction.

RESULTS

Transapical myectomy was indicated for midventricular obstruction (n = 44) or left ventricular remodeling for diastolic heart failure (n = 29). Preoperatively, 74.6% (n = 50) of patients were in New York Heart Association class III/IV heart failure, and 34.3% (n = 23) of patients had experienced syncope or presyncope. Atrial fibrillation was documented in 22 patients (32.8%), and episodes of ventricular arrhythmias were recorded in 30 patients (44.8%). Thrombus was present in the apical aneurysm in 6 patients. During a median (interquartile range) follow-up of 4.9 (1.8-7.6) years, the estimated 1- and 5-year survivals were 98.5% and 94.5%, respectively, which were not significantly different from that of patients undergoing transaortic septal myectomy for obstructive hypertrophic cardiomyopathy (P = .52) or an age- and sex-matched US general population (P = .40).

CONCLUSIONS

Apical aneurysm repair in conjunction with septal myectomy is a safe procedure, and the good long-term survival of patients suggests that the procedure may reduce cardiac-related death in this high-risk hypertrophic cardiomyopathy population.

Management of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy is an important cause of heart failure and arrhythmias, including sudden death, with a major impact on the healthcare system. Genetic causes and different phenotypes are now increasingly being identified for this condition. In addition, specific medications, such as myosin inhibitors, have been recently shown as potentially able to modify its symptoms, hemodynamic abnormalities and clinical course. Our article aims to provide a comprehensive outline of the epidemiology, diagnosis and treatment of hypertrophic cardiomyopathy in the current era.

Apical hypertrophic cardiomyopathy: pathophysiology, diagnosis and management

Since the first description of apical hypertrophic cardiomyopathy (ApHCM) in 1976, contrasting information from all over the world has emerged regarding the natural history of the disease. However, the recommended guidelines on hypertrophic cardiomyopathy (HCM) pay a cursory reference to ApHCM, without ApHCM-specific recommendations to guide the diagnosis and management. In addition, cardiologists may not be aware of certain aspects that are specific to this disease subtype, and a robust understanding of specific disease features can facilitate recognition and timely diagnosis. Therefore, the review covers the incidence, pathogenesis, and characteristics of ApHCM and imaging methods. Echocardiography and cardiovascular magnetic resonance imaging (CMR) are the most commonly used imaging methods. Moreover, this review presents the management strategies of this heterogeneous clinical entity. In this review, we introduce a novel transapical beating-heart septal myectomy procedure for ApHCM patients with a promising short-time result.

Treatment Strategies for Hypertrophic Cardiomyopathy: Surgical

Septal myectomy is a well-established procedure for septal reduction in patients with obstructive hypertrophic cardiomyopathy (HCM) who have not responded to medical treatment. The surgical approach is tailored to the unique pathophysiology and septal morphology of the patient. Extended transaortic myectomy is the standard procedure for patients with isolated subaortic obstruction, the most common type of HCM. However, transapical myectomy is a useful adjunct for patients with long or midventricular obstruction and is our preferred technique for ventricular enlargement in patients with severe symptomatic diastolic heart failure because of extensive apical hypertrophy. Septal myectomy provides excellent postoperative outcomes as regards symptom relief and functional improvement, and operative morbidity and mortality rates are low in experienced centers. This article summarizes our current surgical management of patients with HCM and details operative methods and outcomes.

Contemporary Surgical Management of Hypertrophic Cardiomyopathy

More than half of symptomatic patients with hypertrophic cardiomyopathy (HCM) have left ventricular outflow tract (LVOT) obstruction. Septal reduction therapy by septal myectomy can dramatically relieve exertional dyspnea, chest pain, and presyncope in properly selected patients and is an important management pathway for many patients. The distribution and degree of hypertrophy in patients with obstructive HCM are variable and, as discussed in this review, can influence clinical manifestations of the disease and surgical management. Subaortic septal hypertrophy is the most common phenotype of obstructive HCM associated with LVOT obstruction, but midventricular obstruction and apical hypertrophy may occur in isolation or in conjunction with subaortic septal hypertrophy. In many comprehensive HCM centers, transaortic septal myectomy is the preferred method of septal reduction therapy for symptomatic patients with obstructive HCM. Early surgical approaches aimed at alleviating left LVOT obstruction were hampered by a lack of understanding of the anatomy and pathophysiology of obstructive HCM. With the advent of Doppler echocardiography and, more recently, cardiac magnetic resonance imaging, surgeons can precisely assess the location and degree of obstruction, left ventricular size and function, and morphology and function of the mitral valve. This review discusses the current understanding of the role of septal myectomy in the management of patients with HCM and details contemporary operative methods.

Transapical Approach to Septal Myectomy for Hypertrophic Cardiomyopathy

A 63-year-old symptomatic female with apical hypertrophic cardiomyopathy and diastolic disfunction was admitted to the hospital. What is the best way to manage this patient? This study is a literature review that was performed to answer this question. The following PubMed search strategy was used: 'Hypertrophic obstructive cardiomyopathy' [All Fields] OR 'apical myectomy' [All Fields], NOT 'animal [mh]' NOT 'human [mh]' NOT 'comment [All Fields]' OR 'editorial [All Fields]' OR 'meta-analysis [All Fields]' OR 'practice-guideline [All Fields]' OR 'review [All Fields]' OR 'pediatrics [mh]'. The natural history of the disease has a benign prognosis; however, a watchful strategy was associated with the risk of adverse cardiovacular events. Contrastingly, transapical myectomy was associated with low surgical risk and acceptable outcomes. In our case, the patient underwent transapical myectomy with an unconventional post-operative period. Control echocardiography showed marked left ventricular (LV) cavity enlargement: LV end-diastolic volume, 74 mL; LV ejection fraction, 65%; and LV stroke volume index increased to 27 mL/m2. The patient was discharged 7 days after myectomy. At 6 months post-operation, the patient was NYHA Class I, with a 6 min walk test score of 420 m. Therefore, transapical myectomy may be considered as a feasible procedure in patients with apical hypertrophic cardiomyopathy and progressive heart failure.

A Case Report of Yamaguchi Syndrome in a Saudi Male

Apical hypertrophic cardiomyopathy, also called Yamaguchi syndrome, is a rare variant of hypertrophic cardiomyopathy. Yamaguchi syndrome is characterized by hypertrophy almost confined to the apical region of the left ventricle rather than the left ventricular septum. A case of 65-year-old Saudi man presented to the ER with angina, and the ECG, echocardiogram, and nuclear study confirmed the diagnosis with Yamaguchi. Reporting this case serves to help physicians broaden their vision in approaching patients with symptoms mimicking acute coronary syndrome.

Invasive therapies for symptomatic obstructive hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic condition with multiple different genetic and clinical phenotypes. As awareness for HCM increases, it is important to also be familiar with potential treatment options for the disease. Treatment of HCM can be divided into two different categories, medical and interventional. Typically for obstructive forms of the disease, in which increased septal hypertrophy, abnormally placed papillary muscles, abnormalities in mitral valve or subvalvular apparatus, lead to dynamic left ventricular outflow tract (LVOT) obstruction, treatment is targeted at decreasing obstructive gradients and therefore symptoms. Medications like beta blockers, calcium channel blockers, disopyramide can often accomplish this. However, in patients with severe obstruction or symptoms refractory to medical therapy, either surgical correction of the LVOT obstruction or percutaneous via alcohol septal ablation, are treatment options. In this review, we will focus on the invasive treatment of hypertrophic obstructive cardiomyopathy.

Challenging a dogma: left ventriculotomy can be used safely in children

OBJECTIVE

We aimed to discuss our unit's experience performing left ventriculotomies on children.

METHODS

Between 2000 and 2022, we identified paediatric patients who required left ventriculotomy. Relevant information was gathered retrospectively.

RESULTS

There were eight patients who underwent surgical procedure including left ventriculotomy. The range of weight and age was between 4.5 and 50 kg and 5 months to 17 years, respectively. Left ventriculotomy was primarily performed for the excision of cardiac masses in all but one who had pseudoaneurysm repair. There were no deaths that occurred early or late. Pre-operative and post-operative ejection fractions and fractional shortening values were comparable. There was no arrhythmia detected post-operatively.

CONCLUSIONS

We conclude that an apical left ventriculotomy does not compromise the function of the left ventricle, even in young infants. In selected patients, it may be used safely for surgical access to the left ventricle.

Rare Occurrence of Apical Hypertrophic Cardiomyopathy Among Hispanics

Apical hypertrophic cardiomyopathy (ApHCM), also known as Yamaguchi syndrome represents an uncommon morphologic variant of hypertrophic cardiomyopathy (HCM) in which the myocardial hypertrophy predominantly involves the apex of the left ventricle (LV). It is exemplified by "giant" negative precordial T-waves on electrocardiography and a peculiar "spade-like" configuration of LV cavity on ventriculography historically, and more recently, on echocardiography with use of image enhancing agents. The disease entity was first described in 1976. Available literature reveals that it is prevalent largely among the East-Asian population but is rare among non-Asians. Here, we report a case of a 66-year-old Hispanic male with multiple cardiac histories including persistent atrial fibrillation, non-ST-elevation myocardial infarction (NSTEMI), and ventricular fibrillation cardiac arrest with multiple inconclusive evaluations, who later in life was found to have ApHCM. This case highlights the rare incidence of the disease among the Hispanic population and underlines the challenging diagnosis that requires a high index of suspicion in patients with cardiac symptoms, as ApHCM can masquerade as ischemic coronary heart disease. Our case also describes an unusual clinical course for ApHCM presenting with extreme clinical features, including ventricular arrhythmias and cardiac arrest, unlike the usual benign natural history of this disease.

Extended septal myectomy using a combined trans-aortic and apical approach for long basal and mid-cavity hypertrophic cardiomyopathy

Surgical septal myectomy is the treatment of choice for patients of hypertrophic cardiomyopathy who are symptomatic despite maximal medical therapy. Residual obstruction results in the persistence of symptoms and poorer outcomes. The length (depth) of the septum excised as far towards the apex is important. A combined approach of trans-aortic and trans-apical is needed to achieve this in specific cases with associated mid-cavity obstruction. We present a case of a complex long-segment septal hypertrophy which underwent a successful septal reduction using a combined trans-aortic and trans-apical approach.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-022-01377-4.

Apical Hypertrophic Cardiomyopathy Prompting Aneurysm, Thrombus, and Cardiac Arrest in a 56-Year-Old Female

Hypertrophic cardiomyopathy (HCM) is the most prevalent genetic cardiac disease while apical hypertrophic cardiomyopathy (apHCM) is a rare subset of HCM. The significance of this case report is to present apHCM, its chronological course, and its association with left ventricular aneurysm, thrombosis, and cardiac arrest. We present the case of a 56-year-old female with a past medical history of apHCM who was admitted for substernal chest pain, developed a ventricular storm (VT), and subsequently suffered cardiac arrest; resuscitation of spontaneous circulation (ROSC) was eventually achieved after 10 minutes. It was initially thought that her arrhythmia and hemodynamic decompensation were purely secondary to cocaine use at a party six hours prior to her presentation. During hospitalization, cardiac magnetic resonance imaging demonstrated a severe apHCM apical aneurysm, thrombosis, and a re-entrant circuit as a likely cause of this patient’s decompensation and eventual cardiac arrest. After several days of hemodynamic stability and decreased dependence on intravenous antiarrhythmic medication infusions, she was extubated and transitioned to oral amiodarone and beta-blocker therapy with the implantation of a cardioverter-defibrillator (ICD). In this case, we analyze the continuum of apHCM, a rare subset of HCM once thought to be benign but with the emergence of complications, including aneurysm, thrombus formation, resistant ventricular tachycardia, and cardiac arrest. Recognition and management of apHCM with medical and/or surgical intervention are therefore critical to prevent the aforementioned sequela.

Left Ventricular Enlargement Procedure in a Patient with Diffuse-Type Hypertrophic Cardiomyopathy: A Case Report

Surgical septal myectomy is the preferred treatment option for patients with medically intractable obstructive hypertrophic cardiomyopathy. Extended transaortic septal myectomy is a widely performed surgical procedure for patients with subaortic obstruction. The transapical approach may provide an alternative surgical option in less common phenotypes, such as apical hypertrophy or long-segmental septal hypertrophy. In this report, we describe a case of a procedure performed to achieve left ventricular enlargement procedure using a combined transaortic and transapical dual approach in a patient with diffuse-type hypertrophic cardiomyopathy with apical aneurysm and mid-cavity obstruction.

From Takotsubo to Yamaguchi

Our patient was a 56-year-old Caucasian female who had 34 emergency department visits to our center with recurrent chest pain, of which eleven were of cardiac etiology, involving cardiac causes over the period of seven years. Her chest pain was diagnosed as atypical during her previous visits. Chest CT revealed “ace-of-spades” in the cardiac transverse section. A transthoracic echocardiogram (TTE) demonstrated apical hypertrophy with end-systolic cavity obliteration and an ejection fraction (EF) of 65%-70%, seated amidst a normal-sized left ventricle, with normal wall thickness, indicating Yamaguchi syndrome. In the case report, we portray the need to widen the spectrum of differentials in an encounter with a patient presenting with chest pain.

Transapical Ventricular Remodeling for Hypertrophic Cardiomyopathy With Systolic Cavity Obliteration

BACKGROUND

Some patients with hypertrophic cardiomyopathy (HCM) present with reduced left ventricular (LV) stroke volume and elongated systolic cavity obliteration due to symmetric LV hypertrophy. In this report, we detail our experience with transapical septal myectomy to enlarge the LV volume and to relieve cavity obliteration in this unique subgroup of patients with HCM.

METHODS

We analyzed 38 patients with HCM who had extended symmetric LV hypertrophy and underwent transapical septal myectomy to enlarge the LV cavity from February 2001 to May 2021.

RESULTS

At the time of evaluation for operation, 84.2% (n = 32) of the patients were in New York Heart Association class III/IV. The peak oxygen consumption was 51.5% (44.0%-58.0%) of the normal predicted values on the preoperative exercise stress test (n = 16). Preoperative left atrial sizes in this cohort were enlarged (left atrial volume index, 39.0 [33.5-51.5] mL/m²), despite only 4 patients with moderate or greater mitral valve regurgitation. All patients underwent transapical septal myectomy to enlarge the LV cavity size. There was no postoperative (within 30 days) death. During a median (interquartile range) follow-up of 3.4 (0.7-6.9) years, the estimated survival rates were 100%, 92%, and 87% at 1, 3, and 5 years, respectively. Follow-up surveys suggested that 16 of the 17 contacted patients experienced improvement in their heart function after the procedure.

CONCLUSIONS

Transapical myectomy to enlarge LV cavity volume can be performed safely with good early survival and functional results. This procedure is an important alternative to cardiac transplantation for HCM patients with systolic cavity obliteration and progressive heart failure.

How to build a successful hypertrophic cardiomyopathy team and ensure training the next generation of myectomy surgeons

Transaortic extended septal myectomy is the most reliable method for septal reduction for symptomatic patients with obstructive hypertrophic cardiomyopathy. In addition, surgical management of nonobstructive hypertrophic cardiomyopathy is possible for selected patients with diastolic heart failure and small left ventricular end-diastolic cavity dimensions. These procedures, however, are performed infrequently in many centers, and trainees may not be exposed to the preoperative evaluation and intraoperative management of patients with hypertrophic cardiomyopathy. In this paper, we review what we believe are the central features for creating a successful program for septal myectomy and detail our strategies to optimize instruction in these techniques for residents and fellows.

Extended myectomy for apical hypertrophic cardiomyopathy: a case report

Background

Apical hypertrophic cardiomyopathy is a variant of hypertrophic cardiomyopathy that predominantly affects the apex of the left ventricle and rarely involves the right ventricular apex or both apexes. Heart transplantation is the traditional treatment for apical hypertrophic cardiomyopathy. Although surgical myectomy approaching the apex has been available for decades, its safety and accuracy greatly depend on the surgeon’s skills and experience.

Case presentation

The first case involved a 63-year-old man with apical hypertrophic cardiomyopathy, wherein preoperative contrast computed tomography findings revealed apical hypertrophy and complete apical cavity obliteration. The patient underwent extended myectomy, which revealed the apex cavity filled with abnormal muscles. Using the transaortic approach, the location of the bilateral papillary muscle was confirmed, thereby providing the required orientation. The abnormal muscle mass was successfully resected, and the postoperative end-diastolic volume was extremely increased. The second case involved a 43-year-old man with an apical left ventricular aneurysm and mid-hypertrophic cardiomyopathy obstruction. The thin-walled apical aneurysm contained a large apical-basal band. Upon detecting the bilateral papillary muscle, mid-ventricular myectomy was performed from the apex. During postoperative catheterization, there was no pressure gradient between the left ventricle and aorta.

Conclusions

We reviewed two cases of apical hypertrophic cardiomyopathy, efficiently treated using extended apical myectomy. Although it is an uncommon procedure, the cases presented show how it can be used to successfully manage cases of apical hypertrophic cardiomyopathy. However, it is important to secure the postoperative left ventricular end-diastolic volume.

Surgical management of diastolic heart failure after septal myectomy for obstructive hypertrophic cardiomyopathy

Objective

Some patients with obstructive hypertrophic cardiomyopathy may remain limited after surgical relief of the subaortic obstruction. In this report, we describe experience in surgical management of patients with advanced diastolic heart failure symptoms after adequate transaortic septal myectomy for obstructive hypertrophic cardiomyopathy.

Methods

We identified adult patients who presented with heart failure symptoms after previous transaortic septal myectomy for obstructive hypertrophic cardiomyopathy and underwent repeat sternotomy for transapical myectomy to enlarge a small left ventricular cavity. Functional recovery after hospital dismissal was assessed through a questionnaire-based survey.

Results

Six patients with previous septal myectomy presented with New York Heart Association functional class III symptoms. Preoperative transthoracic Doppler echocardiography confirmed adequate relief of subaortic outflow tract obstruction with only trivial or mild mitral valve regurgitation; left atrial volume index was increased at 46 mL/m² (range, 44-47 mL/m²). Following transapical myectomy, the left ventricular diameter was enlarged from 23 mm (range, 21-27 mm) to 29 mm (range, 27-31 mm) at end-systole and from 40 mm (range, 38-42 mm) to 43 mm (range, 42-50 mm) at end-diastole. All the patients were alive after a median follow-up of 0.6 years (range, 0.4-3.5 years), and 5 patients responded to a postoperative survey and indicated improvement in their heart condition compared with functional status before the repeat myectomy.

Conclusions

Patients with diastolic heart failure after septal myectomy for obstructive hypertrophic cardiomyopathy may present with systolic cavity obliteration due to excessive myocardial hypertrophy. Repeat transapical myectomy can enlarge the left ventricular chamber and augment the diastolic volume, which results in improved physical capacity and patient-perceived functional status.

Videoscope-assisted transaortic myectomy in patients with hypertrophic cardiomyopathy with complex left ventricular anatomy

BACKGROUND

The transaortic approach is the most common method of septal myectomy. However, difficulties arise due to a limited view of the surgical field. Here, we report our experience with videoscope-assisted transaortic myectomy.

METHODS

We reviewed myectomy operations that were performed between July 2015 and June 2019 at Chung-Ang University Hospital, Seoul, South Korea. Patients who previously had cardiac surgery, alcohol septal ablation, or concomitant disease which required combined surgery, were excluded. Among the 21 patients included, 10 patients underwent videoscope-assisted transaortic myectomy (VA group), and 11 patients underwent myectomy in a conventional manner (CO group). The preoperative data, echocardiographic images, operative records, and postoperative outcomes of these patients were reviewed.

RESULTS

There were no differences in baseline characteristics between groups VA and CO. The main indications for videoscope-assisted transaortic myectomy in group VA were midventricular septal muscle resection (70%), abnormal papillary muscle resection (40%), and abnormal chordal connection resection (30%). Eight (80%) patients had multiple indications for videoscope-assisted transaortic myectomy. There was no surgical mortality in either group. Postoperative patients showed less than moderate mitral regurgitation and a New York Heart Association class either III or IV. There were no differences in hospital days (9.5 vs. 12.0 days; p = .383), nor postoperative pressure gradient (14 vs. 15 mmHg; p > .99).

CONCLUSIONS

Videoscope-assisted transaortic myectomy is an effective surgical technique in selective hypertrophic cardiomyopathy patients with complex intraventricular anatomy, diffuse hypertrophy, and midventricular obstruction.

[Dilated phase of hypertrophic cardiomyopathy: high-risk reconstructive surgery as an alternative to heart transplantation]

The authors report the diagnosis and surgical treatment of 5 patients with dilated phase of hypertrophic cardiomyopathy (HCM). Features of these patients are progressive heart failure, double-level blood flow obstruction and the risk of apical aneurysms. Reconstructive remodeling surgery is a reasonable alternative to heart transplantation despite the existing risk.

A Case Report on Diagnostic Approach of a Complex Clinical Scenario: Differentiation Between Coronary Artery Disease and Apical Hypertrophic Cardiomyopathy as a Cause of Recurrent Debilitating Angina

Apical hypertrophic cardiomyopathy (ApHCM) is a clinical challenge when presenting with symptoms of angina plus shortness of breath. An appropriate diagnosis of concurrent coronary artery disease (CAD) is needed for proper diagnosis, risk stratification, and management. We present a case of a 64-year-old gentleman with a history of ApHCM and CAD with previous percutaneous intervention presenting with recurrent angina. A repeat coronary angiography showed no new obstructive lesions. A stress cardiac magnetic resonance imaging was performed, which showed perfusion defect in the apex with apical scarring likely secondary to microvascular disease. The patient was managed medically with the improvement of symptoms. Diagnosis and management of CAD in patients with ApHCM are challenging. Multiple diagnostic modalities may be required for delineating the underlying pathology. Patients should be managed initially with medications. If symptoms are not controlled with medical management, a heart team approach with referral to an advanced center experienced in apical myectomy should be considered.

Nonobstructive Hypertrophic Cardiomyopathy in a Patient With Mitral Prosthesis

Transapical septal myectomy can be performed for patients with nonobstructive hypertrophic cardiomyopathy and diastolic dysfunction to enlarge the LV cavity. The procedure may also include limited shaving of severely hypertrophied papillary muscles. This report illustrates the usefulness of papillary muscle resection to enlarge the left ventricle in a patient with nonobstructive hypertrophic cardiomyopathy and preexisting mitral valve prosthesis.

Cardiac transplantation for hypertrophic cardiomyopathy in the United States 2003-2011

Background:

Cardiac transplant (CT) is the sole option in a minority of hypertrophic cardiomyopathy (HC) adults with refractory symptoms or end-stage disease.

Aims/Methods:

We aimed to examine the trends and hospital outcomes of CT in HC using 2003-2011 Nationwide Inpatient Sample database.

Results:

HC comprised 1.1% of CT (151 of 14,277) performed during this time period (age 45±12 years, 67% male, 79% Caucasians). Number of HC CT increased from 2003 to 2011 (odds ratio=1.174; 95% confidence interval=1.102-1.252; P< 0.001). Comorbidities included congestive heart failure (76%), hypertension (23%), chronic kidney disease (23%), hyperlipidemia (19%), diabetes (13%), and coronary artery disease (10%). Acute in-hospital major adverse events occurred in 1 in 4 (23%) patient and 1 in 25 (3.8%) patients died perioperatively. Other major adverse events included allograft rejection or vasculopathy (23%), postoperative stroke or transient ischemic attack (3.5%), acute renal failure (43%), respiratory failure requiring mechanical ventilation (13%), sepsis (10%) or need for blood transfusion (10%). Compared to 1990-2004 United Network of Organ Sharing registry data (n=303), patients in current cohort had more comorbid conditions [diabetes (13%-vs-0%); chronic obstructive lung disease (9%-vs-1%); P < 0.001 for both), were more likely to be male (66%-vs-48% P< 0.001), were less likely to be Caucasian (79%-vs-86%; P < 0.001) or smokers (3%-vs-17%; P < 0.001) and less often required perioperative circulatory support or hemodialysis (17%-vs-49%, P < 0.001 and 3.2%-vs-8.3%, P = 0.04, respectively).

Conclusion:

HC comprises a small proportion of patients undergoing CT. The annual number of CT in HC has increased in recent years at least in part due to inclusion of patients with more comorbid conditions. Transplant recipients in the current cohort, however, required less postoperative circulatory support or renal replacement therapy.

The Surgeon's View of the Left Ventricular Outflow Tract in Congenital Heart Surgery

Left ventricular outflow tract (LVOT) obstruction is a component of many forms of congenital heart disease, including hypertrophic cardiomyopathy, membranous subaortic stenosis, tunnel subaortic stenosis, and outflow tract obstruction related to atrioventricular septal defects. We have gained a particularly extensive experience with the diagnosis and treatment of hypertrophic cardiomyopathy, having performed septal myectomy in over 3,800 patients. In the setting of this review of LVOT obstruction, we use hypertrophic cardiomyopathy as a template by which other pathologies causing LVOT obstruction can be understood. We review important surgical issues in patient selection, diagnostic evaluation, interpretation of imaging, and operative management. To this end, the review focuses on obstructive hypertrophic cardiomyopathy and then broadens to discuss other pathologies causing LVOT obstruction, with important similarities and differences in their management. These other pathologies share some similar presentations and operative techniques, and at times can be confused with hypertrophic cardiomyopathy, but also have important distinctions of which the surgeon should be aware.

Hypertrophic cardiomyopathy: genetics and clinical perspectives

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease and defined by unexplained isolated progressive myocardial hypertrophy, systolic and diastolic ventricular dysfunction, arrhythmias, sudden cardiac death and histopathologic changes, such as myocyte disarray and myocardial fibrosis. Mutations in genes encoding for proteins of the contractile apparatus of the cardiomyocyte, such as β-myosin heavy chain and myosin binding protein C, have been identified as cause of the disease. Disease is caused by altered biophysical properties of the cardiomyocyte, disturbed calcium handling, and abnormal cellular metabolism. Mutations in sarcomere genes can also activate other signaling pathways via transcriptional activation and can influence non-cardiac cells, such as fibroblasts. Additional environmental, genetic and epigenetic factors result in heterogeneous disease expression. The clinical course of the disease varies greatly with some patients presenting during childhood while others remain asymptomatic until late in life. Patients can present with either heart failure symptoms or the first symptom can be sudden death due to malignant ventricular arrhythmias. The morphological and pathological heterogeneity results in prognosis uncertainty and makes patient management challenging. Current standard therapeutic measures include the prevention of sudden death by prohibition of competitive sport participation and the implantation of cardioverter-defibrillators if indicated, as well as symptomatic heart failure therapies or cardiac transplantation. There exists no causal therapy for this monogenic autosomal-dominant inherited disorder, so that the focus of current management is on early identification of asymptomatic patients at risk through molecular diagnostic and clinical cascade screening of family members, optimal sudden death risk stratification, and timely initiation of preventative therapies to avoid disease progression to the irreversible adverse myocardial remodeling stage. Genetic diagnosis allowing identification of asymptomatic affected patients prior to clinical disease onset, new imaging technologies, and the establishment of international guidelines have optimized treatment and sudden death risk stratification lowering mortality dramatically within the last decade. However, a thorough understanding of underlying disease pathogenesis, regular clinical follow-up, family counseling, and preventative treatment is required to minimize morbidity and mortality of affected patients. This review summarizes current knowledge about molecular genetics and pathogenesis of HCM secondary to mutations in the sarcomere and provides an overview about current evidence and guidelines in clinical patient management. The overview will focus on clinical staging based on disease mechanism allowing timely initiation of preventative measures. An outlook about so far experimental treatments and potential for future therapies will be provided.

Apical myectomy for patients with hypertrophic cardiomyopathy and advanced heart failure

OBJECTIVE

In patients with apical hypertrophic cardiomyopathy, extensive apical hypertrophy may reduce left ventricular end-diastolic volume and contribute to diastolic dysfunction, angina, and ventricular arrhythmias. Transapical myectomy to augment left ventricular cavity size can increase stroke volume and decrease left ventricular end-diastolic pressure. In this study, we describe early outcomes of patients with apical hypertrophic cardiomyopathy after transapical myectomy and compare survival with that of patients with hypertrophic cardiomyopathy listed for heart transplantation.

METHODS

Between September 1993 and March 2017, 113 symptomatic patients with apical hypertrophic cardiomyopathy underwent transapical myectomy. Clinical information, echocardiographic data, and follow-up were reviewed. With the use of a national database, survival was compared with that of patients with hypertrophic cardiomyopathy listed for heart transplantation.

RESULTS

In the surgical cohort, median (interquartile range) age was 50.8 (39.3-60.7) years, and 49 (43%) were male. Preoperatively, 108 patients (96%) were in New York Heart Association class III/IV. All patients underwent transapical myectomy. There were 4 (4%) deaths within 30 days of operation. At last follow-up, 76% of patients reported improvement in symptoms, and 3 patients (3%) subsequently underwent cardiac transplantation for recurrent heart failure. The estimated 1-, 5-, and 10-year survivals were 96%, 87%, and 74%, respectively. Survival appeared superior to patients with hypertrophic cardiomyopathy listed for heart transplant.

CONCLUSIONS

Apical myectomy is beneficial in severely symptomatic patients with apical hypertrophic cardiomyopathy. Early risk of the procedure is low, and approximately 76% maintain clinical improvement with resolution of symptoms. Long-term survival appears better than for patients listed for heart transplantation.

Ventricular Fibrillation Cardiac Arrest in African American Male with Apical Hypertrophic Cardiomyopathy

Apical hypertrophic cardiomyopathy (AHCM) is a rare form of non-obstructive hypertrophic cardiomyopathy. It is rarely reported in African American patients, and more commonly reported in Japanese patients. AHCM involves hypertrophy of the apex of the left ventricle. It is considered to have a benign prognosis in terms of cardiovascular mortality, however arrhythmias and sudden cardiac death have been reported. We report a case of a 49-year-old African American male with a history of hypertension, who presented to the emergency department after in field defibrillation for ventricular fibrillation cardiac arrest with return of spontaneous circulation after 10 minutes of cardiopulmonary resuscitation. Features of left ventricular hypertrophy and deep T-wave inversions in V3-V6 were noted on a 12-lead electrocardiogram which were suggestive of AHCM. Left heart catheterization with left ventriculography and coronary angiography confirmed the diagnosis of AHCM with the classic “ace of spades” sign. This case highlights the rare occurrence of AHCM with ventricular fibrillation cardiac arrest in an African American male, treated with hypertension management, aspirin, atorvastatin and automated implantable cardioverter-defibrillator placement.

What is the role of apical ventriculotomy in children and young adults with hypertrophic cardiomyopathy?

BACKGROUND

The transapical approach has been utilized in adult HCM patients with either midventricular obstruction or a small LV cavity; however, there are little data on its use in children.

METHODS

We retrospectively reviewed all patients (age <21 years) with HCM who underwent a transapical myectomy from January 2002 to December 2016. Indication for surgery was midventricular obstruction in 19/23 (83%) and small LV cavity in 4 (17%). Preoperative symptoms included: dyspnea (96%), chest pain (65%), presyncope (61%), and syncope (35%). The mean age at the time of operation was 14 ± 4.0 years (range, 4-20).

RESULTS

Overall, 23 patients (12 males) underwent transapical myectomy. A concomitant transaortic approach was performed in 16/19 (84%) with obstruction. The intraventricular gradient decreased from 71 mm Hg (IQR 44-92 mm Hg) preoperatively to 18 mm Hg (IQR 8-34 mm Hg, P < .0001) after myectomy. In patients with a small LV cavity, the mean left ventricular end diastolic dimension (LVEDD) increased from 40 ± 3 mm to 46 ± 3 mm (P = .05) after myectomy. There were no early deaths. Postoperative morbidity included complete heart block in 3 patients, 2 of which required pacemakers. Median follow up was 3.5 years (IQR 1.6-5.6). Symptoms improved in 95% of patients; the number of patients in NYHA class 3 or 4 heart failure decreased from 10/23 (43%) preoperatively to 3/23 (13%) postoperatively (P < .0001). Overall survival at 5 years postsurgery was 100%. Transplant-free survival was 91% and 87% at 1 and 5 years, respectively.

CONCLUSION

In children with HCM, transapical myectomy is an effective adjunct to a transaortic approach to abolish midventricular obstruction and it effectively increases LV stroke volume in patients with small LV cavities and nonobstructive HCM. It may be beneficial for these patients with significant symptoms and who have failed medical therapy as a treatment alternative to cardiac transplantation.

Contemporary Septal Reduction Therapy in Drug-Refractory Hypertrophic Obstructive Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a complex and relatively common genetic cardiac disease that has been the subject of intense investigation for over 50 years. Most patients with HCM are asymptomatic, but some develop symptoms, often many years after the appearance of electrocardiographic or echocardiographic evidence of left ventricular hypertrophy. Symptoms due to the left ventricular outflow tract obstruction frequently worsen over time, requiring septal reduction therapy (SRT) despite optimal medical therapy. Percutaneous transluminal septal myocardial ablation (PTSMA) and surgical myectomy are collectively known as SRT. In this review, we will focus on the emerging concept and practical implication of SRT and the available evidence on either PTSMA or surgical myectomy in the literature.

Ineffective and prolonged apical contraction is associated with chest pain and ischaemia in apical hypertrophic cardiomyopathy

OBJECTIVES

To investigate the hypothesis that persistence of apical contraction into diastole is linked to reduced myocardial perfusion and chest pain.

BACKGROUND

Apical hypertrophic cardiomyopathy (HCM) is defined by left ventricular (LV) hypertrophy predominantly of the apex. Hyperdynamic contractility resulting in obliteration of the apical cavity is often present. Apical HCM can lead to drug-refractory chest pain.

METHODS

We retrospectively studied 126 subjects; 76 with apical HCM and 50 controls (31 with asymmetrical septal hypertrophy (ASH) and 19 with non-cardiac chest pain and culprit free angiograms and structurally normal hearts). Perfusion cardiac magnetic resonance imaging (CMR) scans were assessed for myocardial perfusion reserve index (MPRi), late gadolinium enhancement (LGE), LV volumes (muscle and cavity) and regional contractile persistence (apex, mid and basal LV).

RESULTS

In apical HCM, apical MPRi was lower than in normal and ASH controls (p<0.05). In apical HCM, duration of contractile persistence was associated with lower MPRi (p<0.01) and chest pain (p<0.05). In multivariate regression, contractile persistence was independently associated with chest pain (p<0.01) and reduced MPRi (p<0.001).

CONCLUSION

In apical HCM, regional contractile persistence is associated with impaired myocardial perfusion and chest pain. As apical myocardium makes limited contributions to stroke volume, apical contractility is also largely ineffective. Interventions to reduce apical contraction and/or muscle mass are potential therapies for improving symptoms without reducing cardiac output.