First Experience With Percutaneous Mitral Valve Plication as Primary Therapy for Symptomatic Obstructive Hypertrophic Cardiomyopathy

Systolic anterior motion-mediated mitral regurgitation and surgical management in hypertrophic obstructive cardiomyopathy

Mitral regurgitation mediated by systolic anterior motion is a typical manifestation in patients with hypertrophic obstructive cardiomyopathy. Although septal myectomy is currently the preferred treatment for patients with drug-refractory hypertrophic obstructive cardiomyopathy, surgical management of associated mitral regurgitation remains controversial. Whether septal myectomy alone or additional valve procedures are required to correct significant mitral regurgitation depends largely on the pathophysiology of each individual. For intervention purposes, it is important to identify the real systolic anterior motion-mediated mitral regurgitation and clarify the mitral structural abnormalities, as well as the other conditions, which may indicate the degree of mitral valve competence. As a first-line imaging modality in the management of hypertrophic cardiomyopathy, echocardiography could provide crucial information for surgical decision making. In this article, we focus on elucidating the typical echocardiographic features of systolic anterior motion-mediated mitral regurgitation and offer an assessment process to determine other contributors to obstruction and mitral regurgitation. Additionally, guidance for surgical decision making for mitral regurgitation in patients with hypertrophic obstructive cardiomyopathy is discussed.

Mitral Valve Interventions for Hypertrophic Obstructive Cardiomyopathy

The mitral valve (MV) plays an important role in the pathophysiology of hypertrophic obstructive cardiomyopathy (HOCM). Dynamic left ventricular outflow tract (LVOT) obstruction, caused by systolic anterior motion (SAM), is a common occurrence in most patients with hypertrophic cardiomyopathy and is directly associated with the MV apparatus. First line therapy for HOCM patients is pharmacological, and surgical intervention is often indicated for patients who do not respond to medical therapy. Emerging research on mitral disease in HOCM, specifically mitral regurgitation (MR), demonstrates that these patients frequently do not respond to standard therapeutic options, and can benefit from MV interventions. In this review, we describe the involvement of the MV in the pathogenesis of HOCM, discuss medical therapy, and explore available mitral procedures. Surgical myectomy, often combined with various modifications to the MV apparatus, is frequently necessary to achieve a durable resolution of LVOT obstruction and SAM-related MR. Alcohol septal ablation, an alternative to surgical myectomy, will be briefly mentioned. We also emphasize the role of transcatheter edge-to-edge repair (TEER) as a promising and novel therapeutic option for HOCM patients. Over time, TEER has established itself as an effective and safe procedure, demonstrating success across a spectrum of anatomical variations. The leaflet modification and movement restriction achieved through TEER help reduce SAM and, consequently, have the potential to alleviate LVOT obstruction and SAM-related MR. Furthermore, we propose a treatment algorithm for cases where TEER is a potential course of action for patients who are at high risk for other interventions.

Temporal trends and procedural safety of transcatheter mitral valve repair with mitraclip in patients with hypertrophic cardiomyopathy: Insights from the national inpatient sample

Data on utilization and safety of mitral Transcatheter Edge-to-Edge Repair (TEER) among hypertrophic cardiomyopathy (HCM) patients is limited. Our study aimed to assess the national utilization, safety, and clinical outcomes of TEER procedures among HCM patients using a nationwide real-world cohort. HCM patients undergoing TEER hospitalizations between 2015-2020 were identified using ICD-10 (International Classification of Diseases, (ICD-10-CM/PCS). HCM-TEER and HCM No-TEER formed the two comparison groups. Demographic characteristics, baseline comorbidities, procedural complications, inpatient mortality, length of stay (LOS), and cost of hospitalization were compared between the propensity-matched cohorts. Numeric values of 10 or less were not reported per NIS data use agreements. A total of 39,625 weighted cases of TEER were identified from 2015-2020. Of the included patients, 335 patients had the HCM diagnosis. The median age of the HCM-TEER group was 74 (70-79) vs. 79 (72-85) for the no-TEER cohort. The TEER procedure was more frequently performed among Caucasians (86.57%) and females (53.73%). The TEER procedure among HCM patients had similar in-hospital mortality (Adjusted odds ratio: aOR 1.50, 95% CI [0.68-3.29]; p = 0.30) and net adverse cardiac events (NACE) (aOR 1.16, 95% CI [0.73-1.85]; p = 0.51). TEER among HCM was associated with higher odds of gastrointestinal/hematological (aOR 2.33, 95% CI [1.29-4.19]; p = 0.003) complications. However, the odds of cardiac complications (aOR 0.57, 95% CI [0.33-0.96]; p = 0.03) were not higher. The median length of stay was similar in both the groups (median: 2 vs. 2, p = 0.74), although TEER among HCM was associated with higher costs of hospitalization ($44729.36 vs. $40513.82, p < 0.01). TEER is a minimally invasive procedure and could be a safe option for symptomatic HCM patients with significant MR who are poor surgical candidates. Mitral TEER among HCM has been increasingly utilized in recent years in the United States more commonly in obstructive HCM and is associated with no difference in mortality and net adverse cardiac events but higher odds for gastrointestinal/hematological complications than non-HCM patients.

Acute Hemodynamic Compromise After Transcatheter Aortic Valve Replacement Due to Dynamic Left Ventricle Obstruction: A Systematic Review

Acute hemodynamic compromise after transcatheter aortic valve replacement (TAVR) because of dynamic left ventricle (LV) obstruction (LVO), also known as suicide LV, is an infrequent but severe complication of TAVR that is poorly defined in previous studies. Understanding this complication is essential for its prompt diagnosis and optimal treatment. We conducted a systematic literature review using PubMed, Embase, Web of Science, and Medline databases for studies describing acute hemodynamic compromise after TAVR because of dynamic LVO or suicide LV. Each study was reviewed by 2 authors individually for eligibility, and a third author resolved disagreements. From a total of 506 studies, 25 publications were considered for the final analysis. The majority of patients with this condition were women demonstrating a hypertrophic septum, a small ventricle, and hyperdynamic contractility on pre-TAVR echocardiographic assessment. An intraventricular gradient before TAVR was found in half of the cases. Acute hemodynamic compromise after TAVR because of dynamic LVO manifested mainly as significant hypotension and occurred most often immediately after valve deployment. The LV outflow tract was the most common site of obstruction. Advanced therapies were required in nearly 65% of the cases. In conclusion, acute hemodynamic compromise after TAVR because of dynamic LVO occurred almost invariably in women. Echocardiography before TAVR may offer essential information to anticipate this complication. LV outflow tract obstruction appears to carry the highest risk of developing this phenomenon. Advanced therapies should be promptly considered as a bailout strategy in patients with hemodynamic collapse refractory to medical therapy.

Evolving indications for transcatheter mitral edge-to-edge repair

Transcatheter mitral edge-to-edge repair (TEER) is an established procedure for managing mitral regurgitation (MR) in high-risk patients. It is effective in treating both primary and secondary MR, as reported in the surgical and interventional literature. Over time, TEER has gained popularity and achieved procedural success in various anatomies. The less invasive nature of TEER, along with its high safety profile and immediate haemodynamic improvement suggest potential benefits in high-risk populations who are not normally included in major trials. These patients, often deemed unsuitable for surgical intervention, are typically managed conservatively, despite accumulating evidence suggesting the potential of clinical improvement by reducing MR through TEER. Examples include post-myocardial infarction MR, patients with hypertrophic obstructive cardiomyopathy and patients experiencing recurrent MR after surgical intervention. This review discusses the utilisation of TEER beyond recognised indications, examining outcomes and limitations in diverse patient populations. Further studies are warranted to evaluate the benefits of TEER in clinical scenarios beyond the current indications.

Long-Term Clinical Outcome After Alcohol Septal Ablation and Its Periprocedural Predictive Factors in Japan - A Retrospective Observational Study

BACKGROUND

Evidence is limited regarding long-term clinical outcomes after alcohol septal ablation (ASA) for patients with hypertrophic obstructive cardiomyopathy and its periprocedural predictive factors in Japan.

METHODS AND RESULTS

This retrospective observational study included 44 patients who underwent ASA between 1998 and 2022 in a single center. We evaluated the periprocedural change in variables and long-term clinical outcomes after the procedure. The primary outcome was a composite of cardiovascular death or hospitalization for heart failure. The secondary outcome was all-cause death. Using multivariable Poisson regression with robust error variance, we predicted underlying periprocedural factors related to primary outcome development. ASA decreased the median pressure gradient at the left ventricular outflow tract from 88 to 33 mmHg and reduced moderate or severe mitral regurgitation (MR), present in 53% of patients before ASA, to 16%. Over a median 6-year follow-up, the cumulative incidence of the primary outcome at 5 and 10 years was 16.5% and 25.6%, respectively. After multivariable analysis, moderate or severe MR after ASA was significantly associated with the primary outcome (relative risk 8.78; 95% confidence interval 1.34-57.3; P=0.024). All-cause mortality after ASA was 15.1% and 28.9% at 5 and 10 years, respectively.

CONCLUSIONS

This study presents long-term clinical outcomes after ASA in Japan. Moderate or severe MR after ASA was significantly associated with the composite of cardiovascular death or hospitalization for heart failure.

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.

Regulated cell death pathways in cardiomyopathy

Heart disease is a worldwide health menace. Both intractable primary and secondary cardiomyopathies contribute to malignant cardiac dysfunction and mortality. One of the key cellular processes associated with cardiomyopathy is cardiomyocyte death. Cardiomyocytes are terminally differentiated cells with very limited regenerative capacity. Various insults can lead to irreversible damage of cardiomyocytes, contributing to progression of cardiac dysfunction. Accumulating evidence indicates that majority of cardiomyocyte death is executed by regulating molecular pathways, including apoptosis, ferroptosis, autophagy, pyroptosis, and necroptosis. Importantly, these forms of regulated cell death (RCD) are cardinal features in the pathogenesis of various cardiomyopathies, including dilated cardiomyopathy, diabetic cardiomyopathy, sepsis-induced cardiomyopathy, and drug-induced cardiomyopathy. The relevance between abnormity of RCD with adverse outcome of cardiomyopathy has been unequivocally evident. Therefore, there is an urgent need to uncover the molecular and cellular mechanisms for RCD in order to better understand the pathogenesis of cardiomyopathies. In this review, we summarize the latest progress from studies on RCD pathways in cardiomyocytes in context of the pathogenesis of cardiomyopathies, with particular emphasis on apoptosis, necroptosis, ferroptosis, autophagy, and pyroptosis. We also elaborate the crosstalk among various forms of RCD in pathologically stressed myocardium and the prospects of therapeutic applications targeted to various cell death pathways.

Transcatheter Mitral Valve Repair-Beyond the EVEREST and COAPT Criteria

Transcatheter mitral valve repair (TMVr) has emerged as a safe and effective alternative to conventional surgery in patients with primary and secondary mitral regurgitation, especially those at high surgical risk. This review summarises alternative indications for TMVr outside of the traditional criteria derived from the major randomised trials and focusses on less common mitral valve anatomies such as commissural prolapse and bileaflet prolapse, patients with mitral annuloplasty rings, as well as acutely unwell patients with papillary muscle rupture and/or cardiogenic shock. Specific technical challenges involved in treating such patient groups are summarised and described.

The use of MitraClip for nonobstructive hypertrophic cardiomyopathy with mixed severe mitral valve regurgitation

Reports on the treatment of nonobstructive hypertrophic cardiomyopathy (HCM) and severe mitral valve regurgitation (MR) with transcatheter edge-to-edge repair (TEER) are rare. Herein, we present the case of a 68-year-old Chinese man with nonobstructive HCM admitted to our hospital with dyspnoea [New York Heart Association (NYHA) functional Class IV]. Transthoracic echocardiography indicated severe MR in addition to asymmetric hypertrophy of the left ventricle. Despite administering maximal medical therapy for heart failure, the symptoms were not alleviated; because of the high risk of open surgery, TEER was performed for MR. After 4 months of follow-up, the patient showed a significant improvement in symptoms. Herein, we also discuss and review the pathophysiology and treatment strategies for HCM patients with heart failure.

Hypertrophic Cardiomyopathy: Current Treatment and Future Options

Hypertrophic cardiomyopathy (HCM) is a disease involving the cardiac sarcomere. It is associated with various disease-causing gene mutations and phenotypic expressions, managed with different therapies with variable prognoses. The heterogeneity of the disease is evident in the fact that it burdens patients of all ages. HCM is the most prevalent cause of sudden death in athletes. However, several technological advancements and therapeutic options have reduced mortality in patients with HCM to 0.5% per year. In addition, rapid advances in our knowledge of the molecular defects accountable for HCM have strengthened our awareness of the disorder and recommended new approaches to the assessment of prognosis. Despite all these evolutions, a small subgroup of patients with HCM will experience sudden cardiac death, and risk stratification remains a critical challenge. This review provides a practical guide to the updated recommendations for patients with HCM, including clinical updates for diagnosis, family screening, clinical imaging, risk stratification, and management.

Multi-modality management of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant inherited condition defined by left ventricular wall thickness greater than 15 mm in the absence of other conditions that could explain that degree of hypertrophy. Obstructive HCM associated with left ventricular outflow tract obstruction is defined by an intraventricular systolic pressure gradient greater than or equal to 30 mm Hg. Over the past couple of decades, there has been an expansion of both invasive and pharmacotherapeutic options for patients with HCM, with recent guidelines calling for a melody of invasive and non-invasive treatment strategies. There are several invasive therapies including proven therapies such as alcohol septal ablation and septal myectomy. Novel invasive therapies such as MitraClip, radiofrequency septal ablation and SESAME procedure have more recently been promoted. Pharmacological therapy has also dramatically evolved and includes conventional medications such as beta-blockers, calcium channel blockers, and disopyramide. Mavacamten, a novel cardiac myosin inhibitor, may significantly change management. Other myosin inhibitors and modulators are also being developed and tested in large clinical trials. Given significant phenotypical variability in patients with HCM, clinical management can be challenging, and often requires an individualized approach with a combination of invasive and non-invasive options.

A Word of Caution Before Treating Aortic Stenosis in Patients With Concomitant LVOT Obstruction

Patients with aortic stenosis and concomitant left ventricular outflow tract obstruction undergoing transcatheter aortic valve replacement are at risk of hemodynamic collapse after the procedure due to worsening left ventricular outflow tract obstruction. We present 3 cases highlighting the important interplay between these 2 disease states and associated diagnostic and treatment challenges. (Level of Difficulty: Advanced.)

Review of Contemporary Invasive Treatment Approaches and Critical Appraisal of Guidelines on Hypertrophic Obstructive Cardiomyopathy: State-of-the-Art Review

BACKGROUND

Hypertrophic obstructive cardiomyopathy (HOCM) is a heterogeneous disease with different clinical presentations, albeit producing similar dismal long-term outcomes if left untreated. Several approaches are available for the treatment of HOCM; e.g., alcohol septal ablation (ASA) and surgical myectomy (SM). The objectives of the current review were to (1) discuss the place of the standard invasive treatment modalities (ASA and SM) for HOCM; (2) summarize and compare novel techniques for the management of HOCM; (3) analyze current guidelines addressing HOCM management; and (4) offer suggestions for the treatment of complex HOCM presentations.

METHODS

We searched the literature and attempted to gather the most relevant and impactful available evidence on ASA, SM, and other invasive means of treatment of HOCM. The literature search yielded thousands of results, and 103 significant publications were ultimately included.

RESULTS

We critically analyzed available guidelines and provided context in the setting of patient selection for standard and novel treatment modalities. This review offers the most comprehensive analysis to-date of available invasive treatments for HOCM. These include the standard treatments, SM and ASA, as well as novel treatments such as dual-chamber pacing and radiofrequency catheter ablation. We also account for complex pathoanatomic presentations and current guidelines to offer suggestions for tailored care of patients with HOCM. Finally, we consider promising future therapies for HOCM.

CONCLUSIONS

HOCM is a heterogeneous disease associated with poor outcomes if left untreated. Several strategies for treatment of HOCM are available but patient selection for the procedure is crucial.

Transcatheter mitral valve repair for the treatment of severe mitral regurgitation and exertional pre-syncope in a patient with non-obstructive hypertrophic cardiomyopathy: a case report

Background

Hypertrophic cardiomyopathy (HCM) has a complex pathophysiology and heterogeneous phenotypic expression. In obstructive HCM with significant mitral regurgitation (MR), MitraClip device implantation reduces MR severity and symptoms. There are no data regarding MitraClip implantation in patients with non-obstructive HCM and significant MR.

Case summary

A 78-year-old woman with non-obstructive HCM and significant functional MR (3+) was admitted to our centre for dyspnoea and episodes of pre-syncope under light stress. Transthoracic and transoesophageal echocardiography showed a normal left ventricular ejection fraction and normal right heart pressures, an inverted mitral filling pattern, and a central prevalent jet (A2-P2 origin) of MR. Exercise echocardiography performed to verify exercise tolerance was interrupted at the 50-W stage due to severe hypotension and pre-syncope. After transcatheter edge-to-edge repair using the MitraClip system, the patient exhibited a reduction in MR Grade from 3+ to 1+. Follow-up up to 1-year post-procedure revealed noticeable improvements in exercise tolerance and symptoms. There were no further episodes of pre-syncope.

Discussion

In non-obstructive HCM, the pathophysiological role of MR in symptom generation is unknown. In this patient, we speculated that significant MR contributed to the mechanisms responsible for severe hypotension and pre-syncope during exercise. A reduction in MR after MitraClip implantation was associated with symptomatic improvements. Our findings further highlight the potential utility of the exercise stress test in therapeutic decision-making for patients with non-obstructive HCM and MR.

Percutaneous mitral valve edge-to-edge repair for late systolic anterior motion after surgical mitral valve repair: a case report

Background

Late post-operative systolic anterior motion (SAM) is a rare but challenging issue. The feasibility of percutaneous mitral valve edge-to-edge repair (PMVR) using the MitraClip to treat late refractory SAM after surgical mitral valve repair has rarely been reported in the literature.

Case summary

An 88-year-old woman with a history of mitral valve repair for a P2 prolapse 14 years before, presented with signs of congestive heart failure. Transoesophageal echocardiogram (TOE) demonstrated significant SAM of the anterior mitral leaflet, resulting in the detachment from the posterior mitral leaflet in mid-to-late systole and severe mitral regurgitation (MR). The heart team decided to perform PMVR using the MitraClip to simultaneously address the issues of SAM and MR, considering the patient's high surgical risk. TOE after the clip deployment at the medial edge of the mitral valve, where the most severe SAM was detected, confirmed resolution of SAM with marked reduction of MR. The patient was discharged home with good haemodynamic compensation.

Discussion

Post-operative SAM typically occurs immediately after the reparative surgery and resolves with conservative treatment; however, persistent SAM requiring repeat surgery remains a serious concern. As an alternative strategy, the MitraClip has some advantages, including low procedural risk, immediately observable results, and the ability to relocate the clip. Meanwhile, the greater risk of post-procedural mitral stenosis, particularly in patients undergoing mitral repair, should be taken into account. In our case, the clip deployment at the medial edge of the valve could minimize the progression of mitral stenosis with a satisfactory reduction of MR.

Non-pharmaceutical Interventions for Hypertrophic Cardiomyopathy: A Mini Review

Hypertrophic cardiomyopathy is an inherited cardiovascular disease, and 70% of patients have left ventricular outflow tract obstruction. Ventricular septal myectomy has been the gold standard treatment for most patients with refractory symptoms. Due to higher mortality associated with medical facilities with less experience, alcohol septal ablation has been accepted as an alternative to conventional surgical myectomy. It offers lower all-cause in-hospital complications and mortality, which could be potentially more preferable for patients with serious comorbidities. In recent years, radiofrequency ablation, providing another option with reproducibility and a low risk of permanent atrioventricular block, has become an effective invasive treatment to relieve left ventricular outflow tract obstruction. Moreover, substantial progress has been made in gene therapy for hypertrophic cardiomyopathy. The principal objective of this review is to present recent advances in non-pharmaceutical interventions in hypertrophic cardiomyopathy.

Initial experience with percutaneous mitral valve repair in patients with cardiac amyloidosis

BACKGROUND

Percutaneous mitral valve repair (PMVR) is a therapeutic option for severe mitral regurgitation (MR) in patients with heart failure due to differential aetiologies. However, only little is known about the safety and efficacy of this procedure in patients with amyloid cardiomyopathy.

METHODS

Five patients with cardiac amyloidosis and moderate to severe or severe MR undergoing PMVR were analysed retrospectively and compared to seven patients with cardiac amyloidosis and severe MR without intervention. Clinical and functional data, renal function and cardiac biomarkers as well as established risk scores for cardiac amyloidosis were assessed. Primary endpoint was the reduction in MR one year after PMVR. Secondary endpoints were safety, overall mortality after 12 months compared with the control group, as well as changes in clinical and functional parameters.

RESULTS

Amyloidosis risk assessment documented amyloid cardiomyopathy at an advanced stage in all patients. Procedural, technical and device success of PMVR were all 100% and residual MR remained mild to moderate at 12 months follow-up (P = .038 vs before PMVR). Differences in survival compared with the control (no PMVR) group pointed to a possible survival benefit in the PMVR group (P = .02).

CONCLUSION

PMVR is a feasible and safe procedure in patients with cardiac amyloidosis and might carry a possible survival benefit in this patient group.

Unmet needs in the treatment of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a complex heterogeneous cardiovascular disorder characterized by hypertrophied and disorganized myocytes with varying degrees of interstitial fibrosis. The current management strategies include genetic and familial screening, symptom control and prevention of sudden cardiac death in those at high risk. Until recently, septal reduction therapy and heart transplantation were the only disease modifying treatments available to manage HCM, but emerging pharmacotherapies show promising results in controlled clinical trials. In this article, we will review the unmet needs in the treatment of HCM incorporating novel therapies.

State of the Art: Transcatheter Edge-to-Edge Repair for Complex Mitral Regurgitation

Transcatheter edge-to-edge mitral valve repair has revolutionized the treatment of primary and secondary mitral regurgitation. The landmark EVEREST (Endovascular Valve Edge-to-Edge Repair Study) and COAPT (Clinical Outcomes Assessment of the MitraClip Percutaneous Therapy for High Surgical Risk Patients) trials included only clinically stable patients with favorable mitral valve anatomy for edge-to-edge repair. However, since its initial commercial approval in the United States, growing operator experience, device iterations, and improvements in intraprocedural imaging have led to an expansion in the use of transcatheter edge-to-edge repair to more complex mitral valve pathologies and clinical scenarios, many of which were previously considered contraindications for the procedure. Because patients with prohibitive surgical risk are often older and present with complex mitral valve disease, knowledge of the potential effectiveness, versatility, and technical approach to a broad range of anatomy is clinically relevant. In this review the authors examine the current experience with mitral valve transcatheter edge-to-edge repair in various pathologies and scenarios that go well beyond the EVEREST II trial inclusion criteria.

Emerging Medical Treatment for Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a common myocardial disease characterized by otherwise unexplained left ventricular hypertrophy. The main cause of disabling symptoms in patients with HCM is left ventricular outflow tract (LVOT) obstruction. This phenomenon is multifactorial, determined both by anatomical and functional abnormalities: myocardial hypercontractility is believed to represent one of its major determinants. The anatomical anomalies are targeted by surgical interventions, whereas attenuating hypercontractility is the objective of old and new drugs including the novel class of allosteric myosin inhibitors. This review summarizes the current treatment modalities and discusses the emerging therapeutical opportunities focusing on the recently developed cardiac myosin ATPase inhibitors Mavacamten and CK-274. Novel surgical and interventional approaches are also discussed.

Asian Pacific Society of Cardiology Consensus Recommendations on the Use of MitraClip for Mitral Regurgitation

Transcatheter mitral valve repair with the MitraClip, a catheter-based percutaneous edge-to-edge repair technique to correct mitral regurgitation (MR), has been demonstrated in Western studies to be an effective and safe MR treatment strategy. However, randomised clinical trial data on its use in Asian-Pacific patients is limited. Hence, the Asian Pacific Society of Cardiology convened an expert panel to review the available literature on MitraClip and to develop consensus recommendations to guide clinicians in the region. The panel developed statements on the use of MitraClip for the management of degenerative MR, functional MR, and other less common indications, such as acute MR, dynamic MR, hypertrophic obstructive cardiomyopathy, and MR after failed surgical repair. Each statement was voted on by each panel member and consensus was reached when 80% of experts voted 'agree' or 'neutral'. This consensus-building process resulted in 10 consensus recommendations to guide general cardiologists in the evaluation and management of patients in whom MitraClip treatment is being contemplated.

Edge-to-edge repair: past challenge, current case selection and future advances

Severe mitral regurgitation (MR) is associated with heart failure and impaired survival with an annual mortality risk in excess of 5% per year for unoperated patients. Despite availability of surgical mitral valve interventions, as many as half of all patients with severe MR do not receive interventions. Transcatheter edge-to-edge repair with MitraClip has been a revolutionary therapy for MR, with over 100,000 treated patients worldwide. The usage has also expanded to different challenging anatomies as well as tricuspid regurgitation. Additionally, other transcatheter edge-to-edge repair devices are being studied. The evolution of these devices as well as what to expect in the future will be discussed here.

Trapezoidal resection of an elongated anterior mitral leaflet and Alfieri stitch in hypertrophic cardiomyopathy

Background

In individuals with hypertrophic obstructive cardiomyopathy, elongated anterior mitral leaflets are commonly associated with systolic anterior motion. In patients with mild septal hypertrophy, a myectomy is considered insufficient to relieve systolic anterior motion and left ventricular outflow tract obstruction.

Case presentation

In the patient, who had relatively mild septal hypertrophy, the section of the anterior leaflet protruding into the left ventricular outflow tract was resected, concomitant with septal myectomy and the relocation of the papillary muscles. An edge-to-edge stitch was placed at the uppermost segment of the coaptation zone. Using these manoeuvres, systolic anterior motion, left ventricular outflow tract obstruction and mitral regurgitation were successfully resolved postoperatively.

Conclusions

We describe a surgical technique with an edge-to-edge suture for the resection of an elongated anterior mitral leaflet. In combination with septal myectomy and relocation of the papillary muscles, this technique is a simple and viable option, especially when septal hypertrophy is not severe.

Three-Dimensional Imaging and Dynamic Modeling of Systolic Anterior Motion of the Mitral Valve

Left ventricular outflow tract (LVOT) obstruction in hypertrophic cardiomyopathy (HCM) is often caused by systolic anterior motion (SAM) of the mitral valve caused by the interplay between increased left ventricular (LV) wall thickness and an abnormal mitral valve anatomy and geometry. Three-dimensional (3D) echocardiographic imaging of the mitral valve has revolutionized the practice of cardiology, paving the way for new methods to see and treat valvular heart disease. Here we present the novel and incremental value of 3D transesophageal echocardiography (TEE) of SAM visualization. This review first provides step-by-step instructions on acquiring and optimizing 3D TEE imaging of SAM. It then describes the unique and novel findings using standard 3D TEE rendering as well as dynamic mitral valve modeling of SAM from 3D data sets, which can provide a more detailed visualization of SAM features. The findings include double-orifice LVOT caused by the residual leaflet, the dolphin smile phenomenon, and delineation of SAM width. Finally, the review discusses the essential role of 3D TEE imaging for preprocedural assessment and intraprocedural guidance of surgical and novel percutaneous treatments of SAM.

Conceiving MitraClip as a tool: percutaneous edge-to-edge repair in complex mitral valve anatomies

Improvements in procedural technique and intra-procedural imaging have progressively expanded the indications of percutaneous edge-to-edge technique. To date in higher volume centres and by experienced operators MitraClip is used for the treatment of complex anatomies and challenging cases in high risk-inoperable patients. This progressive step is superimposable to what observed in surgery for edge-to-edge surgery (Alfieri's technique). Moreover, the results of clinical studies on the treatment of patients with high surgical risk and functional mitral insufficiency have confirmed that the main goal to be achieved for improving clinical outcomes of patients with severe mitral regurgitation (MR) is the reduction of MR itself. The MitraClip should therefore be considered as a tool to achieve this goal in addition to medical therapy. Nowadays, evaluation of patient's candidacy to MitraClip procedure, discussed in local Heart Team, must take into account not only the clinical features of patients but even the experience of the operators and the volume of the centre, which are mostly related to the probability to achieve good procedural results. This 'relative feasibility' of challenges cases by experienced operators should always been taken into account in selecting patients for MitraClip. Here, we present a review of the literature available on the treatment of complex and challenging lesions.

Percutaneous Edge-to-Edge Mitral Valve Repair

Percutaneous edge-to-edge mitral valve repair, using the MitraClip device for severe mitral regurgitation (MR) was first introduced in 2003. Since then, more than 100,000 cases have been performed worldwide and it remains the most established percutaneous therapy available for the treatment of severe MR. Currently, it is indicated for severe, symptomatic functional MR in patients who continue to have significant symptoms despite optimal guideline directed medical therapy, as well as in symptomatic patients with severe degenerative MR who are deemed too high risk for conventional surgical therapy in the opinion of the heart team. In this paper, we discuss the evolution of the MitraClip device, the clinical studies supporting its use as well as the important concept of proportionate and disproportionate MR.

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

OBJECTIVE

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

RESULTS

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

CONCLUSION

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

The use of MitraClip to prevent posttranscatheter aortic valve replacement left ventricular "suicide"

Patients with concomitant severe aortic stenosis (AS) and left ventricular outflow tract (LVOT) obstruction undergoing transcatheter aortic valve replacement (TAVR) are at risk for hemodynamic collapse due to a sudden decrease in afterload causing worsening LVOT obstruction. We present a case of an 88-year-old female with symptomatic, severe AS, and LVOT obstruction with systolic anterior motion (SAM) of the mitral leaflet in whom alcohol septal ablation was contraindicated secondary to a chronic total occlusion of the right coronary artery that filled retrograde via septal collaterals. MitraClip at the time of TAVR was successfully performed to treat SAM with subsequent stabilization of LVOT gradients despite treatment of the patient's AS. This novel approach may represent a feasible option to prevent hemodynamic complications after TAVR in patients with significant LVOT obstruction secondary to SAM and AS.

Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disease. The disease is characterized by marked variability in morphological expression and natural history, ranging from asymptomatic to heart failure or sudden cardiac death. Left ventricular hypertrophy and abnormal ventricular configuration result in dynamic left ventricular outflow obstruction in most patients. The goal of pharmacological therapy in HCM is to alleviate the symptoms, and it includes pharmacotherapies and septal reduction therapies. In this review, we summarize the relevant clinical issues and treatment options of HCM.

Hypertrophic cardiomyopathy: the future of treatment

Hypertrophic cardiomyopathy (HCM) is a heterogeneous genetic disorder most often caused by sarcomeric mutations resulting in left ventricular hypertrophy, fibrosis, hypercontractility, and reduced compliance. It is the most common inherited monogenic cardiac condition, affecting 0.2% of the population. Whereas currently available therapies for HCM have been effective in reducing morbidity, there remain important unmet needs in the treatment of both the obstructive and non-obstructive phenotypes. Novel pharmacotherapies directly target the molecular underpinnings of HCM, while innovative procedural techniques may soon offer minimally-invasive alternatives to current septal reduction therapy. With the advent of embryonic gene editing, there now exists the potential to correct underlying genetic mutations that may result in disease. This article details the recent developments in the treatment of HCM including pharmacotherapy, septal reduction procedures, mitral valve manipulation, and gene-based therapies.

Killing two birds with one stone-MitraClip for flail P2 and systolic anterior motion of mitral valve: a case report

BACKGROUND

The MitraClip system has been used extensively in high-risk patients with severe degenerative mitral regurgitation (MR). Recent reports have demonstrated the feasibility of using the MitraClip device to treat systolic anterior motion (SAM) of the mitral valve in obstructive hypertrophic cardiomyopathy (HOCM).

CASE SUMMARY

We report the case of a 76-year-old lady who had both symptomatic severe degenerative MR and HOCM that were refractory to medical therapy. Both pathologies were treated successfully using the MitraClip system.

DISCUSSION

In patients who are deemed to be at high risk for open surgery, our case demonstrated the feasibility of a percutaneous avenue, the MitraClip system, to treat not just degenerative MR, but also SAM from HOCM in a single procedure.

Routine Papillary Muscle Realignment and Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

Septal myectomy has been the mainstay of the surgical treatment of obstructive hypertrophic cardiomyopathy (HCM); however, recently there is growing appreciation for associated mitral valve abnormalities that contribute to left ventricular outflow tract (LVOT) obstruction. In this study, we describe our experience with combined papillary muscle realignment (PMR) and septal myectomy for the treatment of obstructive HCM.

METHODS

We identified 44 patients undergoing surgery for obstructive HCM whose anatomy was amenable to combined PMR and septal myectomy at our institution over a 20-month period. All patients underwent resting and stress echocardiography preoperatively and postoperatively. Demographic, clinical, and imaging data were prospectively collected in a cardiac surgery database.

RESULTS

Patient age ranged broadly, with mean age of 54 (range, 18 to 76) years. Preoperatively, 70% of patients were New York Heart Association functional class III or IV, the mean stress LVOT gradient was 144 mm Hg, and severe mitral regurgitation (MR) with stress was seen in 81%. Additional procedures included division of myocardial bands (50%) and chordae (43%) and resection of accessory papillary muscles (25%). Following the procedure, mean resting and stress gradients were reduced to normal (12 and 27 mm Hg, respectively; p < 0.0001). No patient had severe MR and only 3 (6.8%) had moderate MR (p < 0.0001). Mean length of stay was 6 days and there were no mortalities.

CONCLUSIONS

Septal myectomy combined with PMR is a safe, highly effective, and reproducible procedure that reliably relieves LVOT obstruction and corrects MR without the need for mitral valve repair or replacement.

Endoscopic Port AccessTM left ventricle outflow tract resection and atrioventricular valve surgery

The continuous evolution in robotic-, endoscopic- and trans-catheter cardiac interventions resulted in innovative techniques that simultaneously address left ventricular outflow tract obstruction (LVOTO) and concomitant atrioventricular valve (AVV) pathology in the context of hypertrophic obstructive cardiomyopathy (HOCM). We present our brief report of 13 consecutive HOCM patients with concomitant AVV disease, who underwent endoscopic left ventricular septal myomectomy (LVSM) and AVV surgery by Endoscopic Port Access^TM Surgery (EPAS) between March 1st 2010 and October 31st 2015. Our EPAS technique in the context of HOCM utilizes peripheral cardiopulmonary bypass, endo-aortic balloon occlusion and a 4-cm right antero-lateral thoracic working port. Access to the LVOTO is obtained by detaching the anterior mitral valve (MV) leaflet from the annulus. Controlled sharp LVSM is then performed from the aortic leaflet base to the papillary muscles. Subsequent routine AVV surgery is performed using long shafted instruments. There were no sternotomy conversions, LVSM complications or 30-day mortalities. The mean length of hospitalization was 17.7±18.1 days. Long-term clinical and echocardiographic analysis of 645.7 patient-months (n=13, 100.0% complete) identified two late mortalities, which were not procedure-, HOCM- or AVV-related. All patients (n=13, 100.0%), including the late mortalities, had significant improvement in their quality of life, a 100% long-term freedom from re-intervention and no residual peak instantaneous LVOTO gradients more than 15 mmHg. This brief report emphasises that simultaneous LVSM and concomitant AVV surgery by EPAS can safely be performed in experienced centres with favourable long-term outcomes.