Mitral Regurgitation in Patients With Hypertrophic Obstructive Cardiomyopathy

Midterm Outcomes: A Comprehensive Approach to Surgery for Hypertrophic Obstructive Cardiomyopathy

BACKGROUND

Left ventricular outflow tract (LVOT) obstruction in obstructive hypertrophic cardiomyopathy (HCM) is caused by a constellation of abnormalities. This study reviewed outcomes of a comprehensive approach to correct these abnormalities during surgery.

METHODS

This was a single-institution study of patients with HCM who underwent septal myectomy from 2016 to 2023. Their New York Heart Association functional classification and most recent echocardiogram that estimated LVOT gradient and mitral valve function were tracked.

RESULTS

The study included 103 patients with a mean age of 54 years (interquartile range, 40-67 years) and common comorbidities: hypertension (50%) and atrial fibrillation (25%). On average, the preprocedure resting echocardiogram showed an LVOT gradient of 36.4 mm Hg and moderate or severe mitral regurgitation in 50.5% of patients. All patients underwent septal myectomy, and associated abnormalities contributing to LVOT obstruction were addressed. Elongation of the anterior leaflet of the mitral valve was typically treated with papillary muscle realignment (72%). Aberrant papillary muscle heads and elongated secondary chordae tendineae contributing to systolic anterior motion were resected (66%). Myocardial bands, including apicoseptal bands contributing to LVOT obstruction, were resected (68%). With an average follow-up of 4 years, 91% of patients were considered to be in New York Heart Association functional class I or II. Long-term echocardiographic follow-up showed a mean peak LVOT gradient of 11 mm Hg (interquartile range, 4-13 mm Hg). Only 1 patient had more than mild mitral regurgitation.

CONCLUSIONS

A comprehensive surgical approach to HCM that addresses the entire constellation of abnormalities associated with HCM, including mitral valve anterior leaflet elongation, aberrant or displaced mitral valve subvalvular apparatus, and myocardial bands, leads to outstanding midterm outcomes.

Midterm Outcomes of Percutaneous Intramyocardial Septal Radiofrequency Ablation for Hypertrophic Cardiomyopathy: A Single-Center, Observational Study

BACKGROUND

Percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) has been reported to be safe and effective at midterm follow-up to treat drug-refractory hypertrophic obstructive cardiomyopathy in a single center. However, data from other centers are lacking. This retrospective cohort study aimed to investigate the efficacy and safety of PIMSRA from another independent center.

METHODS AND RESULTS

PIMSRA was performed in 76 patients with hypertrophic obstructive cardiomyopathy in our center from April 2020 to June 2023. The primary outcome was the reduction of left ventricular outflow tract gradient after 6 months or more post-PIMSRA. Secondary outcomes were periprocedural major adverse clinical events. Sixty-one patients returned to the hospital for follow-up 6 to 30 (median, 14) months after the procedure. At the last follow-up of the 61 patients, the maximum septal thickness decreased from a median of 23.6 (interquartile range, 20.5-26.4) to 19.1 (interquartile range, 16.0-22.1) mm (P<0.001) and the left ventricular outflow tract peak gradient at rest decreased from a median of 70.0 (interquartile range, 29.1-107.5) to 20.0 (interquartile range, 10.8-48.8) mm Hg (P<0.001). The percentage of patients with symptoms of New York Heart Association functional class III/IV decreased from 51% to 0%. Of all 76 patients, there was no in-hospital or 30-day death, no right or left branch block, and no permanent pacemaker implantation. Six (8%) patients had pericardial effusion, with 1 experiencing cardiac tamponade and ventricular fibrillation, and 1 (1%) patient developed septal branch aneurysm that was treated with coil occlusion.

CONCLUSIONS

PIMSRA allows for the reduction in the left ventricular outflow tract gradient and enhances symptomatic improvement, with a limited incidence of adverse events and complications among patients with hypertrophic obstructive cardiomyopathy.

Mitral Leaflet Shortening as an Ancillary Procedure in Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

Mitral leaflet elongation is common in hypertrophic cardiomyopathy (HCM), contributes to obstructive physiology, and presents a challenge to the dual surgical goals of abolition of outflow gradients and abolition of mitral regurgitation. Anterior leaflet shortening, performed as an ancillary surgical procedure during myectomy, is controversial.

METHODS

This was a retrospective study of all patients undergoing myectomy from January 2010 to March 2020, with analysis of survival and echocardiographic results. The study compared outcomes of patients treated with myectomy and concomitant mitral leaflet shortening with patients treated with myectomy alone. Over this time, the technique for mitral shortening evolved from anterior leaflet plication to residual leaflet excision (ReLex).

RESULTS

Myectomy was performed in 416 patients aged 57.5 ± 13.6 years, and 204 (49%) patients were female. Average follow-up was 5.4 ± 2.8 years. Survival follow-up was complete in 415 patients. Myectomy without valve replacement was performed in 332 patients, of whom 192 had mitral valve shortening (58%). Mitral leaflet plication was performed in 73 patients, ReLex in 151, and both procedures in 32. Hospital mortality for patients undergoing myectomy was 0.7%. At 8 years, cumulative survival was 95% for both the myectomy combined with leaflet shortening group and the myectomy alone group, with no difference in survival between the 2 groups. There was no difference in survival between the anterior leaflet plication and ReLex groups. Echocardiography 2.5 years after surgery showed a decrease in resting and provoked gradients, mitral regurgitation, and left atrial volume and no difference in key variables between patients who underwent ancillary leaflet shortening and patients who underwent myectomy alone.

CONCLUSIONS

These results affirm that mitral shortening may be an appropriate surgical judgment for selected patients.

2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy" provides recommendations to guide clinicians in the management of patients with hypertrophic cardiomyopathy.

METHODS

A comprehensive literature search was conducted from September 14, 2022, to November 22, 2022, encompassing studies, reviews, and other evidence on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through May 23, 2023, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Hypertrophic cardiomyopathy remains a common genetic heart disease reported in populations globally. Recommendations from the "2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy" have been updated with new evidence to guide clinicians.

2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy" provides recommendations to guide clinicians in the management of patients with hypertrophic cardiomyopathy.

METHODS

A comprehensive literature search was conducted from September 14, 2022, to November 22, 2022, encompassing studies, reviews, and other evidence on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through May 23, 2023, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Hypertrophic cardiomyopathy remains a common genetic heart disease reported in populations globally. Recommendations from the "2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy" have been updated with new evidence to guide clinicians.

Interventions in Hypertrophic Obstructive Cardiomyopathy

Obstructive hypertrophic cardiomyopathy is the most common genetically transmitted cardiomyopathy that is associated with significant morbidity and mortality. Despite contemporary treatments and interventions, the management of patients with obstructive hypertrophic cardiomyopathy remains poorly defined compared with other branches of cardiology. In this review, we discuss established and novel therapeutic interventions in patients with obstructive hypertrophic cardiomyopathy with a focus on percutaneous and surgical strategies including surgical myectomy, mitral valve repair or replacement, percutaneous alcohol septal ablation, pacemaker and cardioverter-defibrillator implantation, septal embolization, radiofrequency endocardial catheter ablation, and percutaneous intramyocardial septal radiofrequency ablation.

Impact of concomitant surgical interventions on outcomes of septal myectomy in obstructive hypertrophic cardiomyopathy

BACKGROUND

Septal myectomy (SM) is offered to symptomatic patients with obstructive hypertrophic cardiomyopathy (oHCM) despite medical therapy. Frequently, patients undergo concomitant planned or ad-hoc mitral valve replacement (MVR), aortic valve replacement (SAVR), or coronary artery bypass grafting (CABG).

OBJECTIVES

We sought to assess characteristics and outcomes of patients with oHCM undergoing concomitant surgical interventions at the time of SM.

METHODS

The National Readmission Databases were used to identify all SM admissions in the United States (2010-2019). Patients undergoing SM were stratified into: isolated SM (±MV repair), SM + CABG only, SM + MVR, SM + SAVR, and SM + MVR + SAVR. Primary outcomes were in-hospital mortality, in-hospital adverse events, and 30-day readmission.

RESULTS

12,063 encounters of patients who underwent SM were included (56.1% isolated SM, 9.0% SM + CABG only, 17.5% SM + MVR, 13.1% SM + SAVR, and 4.3% SM + MVR + SAVR). Patients who underwent isolated SM were younger (54.3 vs. 67.1 years-old, p < 0.01) and had lower overall comorbidity burden. In-hospital mortality was lowest in isolated SM, followed by CABG only, SM + SAVR, SM + MVR, and SM + SAVR+MVR groups (2.3% vs. 3.7% vs. 5.3% vs. 6.7% vs. 13.7%, p < 0.01), respectively. SM with combined surgical interventions was associated with higher adverse in-hospital events (24.3% vs. 11.1%, p < 0.01) and 30-day readmissions (16.9% vs. 10.4%, p < 0.01). MV repair performed concomitantly with SM was not associated with increased in-hospital mortality (3.9% vs. 3.4%, p = 0.72; aOR 0.99; 95% CI: 0.54-1.80, p = 0.97]) or adverse clinical events.

CONCLUSIONS

In SM for oHCM, patients undergoing concomitant surgical interventions were characteristically distinct. Aside from MV repair, concomitant interventions were associated with worse in-hospital death, adverse in-hospital events, and 30-day readmission.

Comparing long-term outcomes of septal myectomy and mitral valve replacement in hypertrophic cardiomyopathy patients: A retrospective cohort study in Iran

Background

Hypertrophic cardiomyopathy (HCM) affects millions of individuals worldwide. In severe cases, it can cause life-threatening conditions such as left ventricular outflow tract (LVOT) obstruction, mitral regurgitation (MR), and sudden cardiac death, making surgical treatment necessary. This study aimed to report the long-term outcomes of HCM patients undergoing septal myectomy or mitral valve replacement (MVR) and compare the results between different types of surgeries.

Methods

This was a retrospective cohort study on HCM patients who underwent surgical treatment in an Iranian referral center between 2005 and 2021. Patients were divided into three groups according to the type of surgery received: septal myectomy, MVR, or a combination of both surgeries. Patient characteristics, surgical and echocardiographic features, and in-hospital and long-term outcomes were reported and compared between the three groups.

Results

A total of 102 patients with an average age of 53.3 ± 16.9 were included. Twenty-six patients had septal myectomy, 23 had MVR, and 53 had combined septal myectomy and MVR surgery. All surgeries were associated with a significant reduction in interventricular septum thickness and LVOT gradients. After a median of 6.8-year follow-up time, patients with an isolated septal myectomy had significantly lower mortality and major adverse cardiac and cerebrovascular events rates than the other groups.

Conclusion

Isolated septal myectomy showed better long-term survival rates and can correct HCM-related MR, while MVR should be preserved only for intrinsic valve defects. More extensive studies are needed to confirm these findings and achieve a comprehensive guideline on surgical treatment of HCM.

Extended septal myectomy for obstructive hypertrophic cardiomyopathy and its impact on mitral valve function

AIMS

Septal myectomy is the treatment of choice for hypertrophic obstructive cardiomyopathy (HOCM). Around 30-60% of patients with HOCM have a secondary mitral valve regurgitation due to systolic anterior motion (SAM). We report our experience with extended septal myectomy and its impact on the incidence of concomitant mitral valve procedures.

METHODS

This is a retrospective study on 84 patients who underwent SM from January 2008 to February 2022. Surgical procedure was performed according to the concept of 'extended myectomy' described by Messmer in 1994. Follow-up outcomes in terms of survival, hospital admissions for heart failure or MV disease, cardiac reoperations, and pacemaker (PMK) implantation were recorded.

RESULTS

Mean age was 61 ± 15 years. Mitral valve surgery was performed in seven cases (8%); particularly only one patient without degenerative mitral valve disease underwent mitral valve surgery, with a plicature of the posterior leaflet. In-hospital mortality was 5%. Mitral valve regurgitation greater than mild was present in four patients (5%) at discharge. Twelve-year survival was 78 ± 22%. Cumulative incidence of rehospitalization for heart failure and rehospitalization for mitral valve disease was 10 ± 4 and 2.5 ± 2.5%, respectively. PMK implantation was 5% at discharge, with a cumulative incidence of 15 ± 7%. Freedom from cardiac reoperations was 100%.

CONCLUSION

Septal myectomy for HOCM is associated with good outcomes. Although concomitant surgery on the mitral valve to address SAM and associated regurgitation has been advocated, these procedures were needed in our practice only in patients with intrinsic mitral valve disease. Adequate myectomy addresses the underlying pathophysiology in most patients.

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.

Morphological and Genetic Aspects for Post-Mortem Diagnosis of Hypertrophic Cardiomyopathy: A Systematic Review

Hypertrophic cardiomyopathy (HCM) is one of the most common genetic cardiovascular diseases, and it shows an autosomal dominant pattern of inheritance. HCM can be clinically silent, and sudden unexpected death due to malignant arrhythmias may be the first manifestation. Thus, the HCM diagnosis could be performed at a clinical and judicial autopsy and offer useful findings on morphological features; moreover, it could integrate the knowledge on the genetic aspect of the disease. This review aims to systematically analyze the literature on the main post-mortem investigations and the related findings of HCM to reach a well-characterized and stringent diagnosis; the review was performed using PubMed and Scopus databases. The articles on the post-mortem evaluation of HCM by gross and microscopic evaluation, imaging, and genetic test were selected; a total of 36 studies were included. HCM was described with a wide range of gross findings, and there were cases without morphological alterations. Myocyte hypertrophy, disarray, fibrosis, and small vessel disease were the main histological findings. The post-mortem genetic tests allowed the diagnosis to be reached in cases without morpho-structural abnormalities; clinical and forensic pathologists have a pivotal role in HCM diagnosis; they contribute to a better definition of the disease and also provide data on the genotype-phenotype correlation, which is useful for clinical research.

Transapical beating-heart septal myectomy for hypertrophic cardiomyopathy with latent obstruction

OBJECTIVES

A novel transapical beating-heart septal myectomy (TA-BSM) procedure was performed for patients with latent obstruction through the left intercostal incision and without cardiopulmonary bypass. This study aims to demonstrate the experience of the TA-BSM procedure for patients with latent obstruction and compare outcomes to patients with resting obstruction.

METHODS

We studied 120 symptomatic hypertrophic obstructive cardiomyopathy patients (33 with latent obstruction and 87 with resting obstruction) who underwent TA-BSM. Demographic profiles, echocardiogram-derived ventricular morphology and haemodynamics and clinical outcomes were analysed.

RESULTS

There were no important differences in baseline clinical characteristics between patients with latent obstruction and resting obstruction, including age, symptoms, comorbidities and medical history. Patients with latent obstruction had lower basal septum thickness, higher midventricular wall thickness, smaller left atrial chamber size and more frequency of mitral subvalvular anomalies. There was no difference in early (<30 days) deaths (0/33 vs 1/87, P > 0.999) and mid-term survival between patients with latent obstruction and resting obstruction. At 6 months after surgery, 31 (93.9%) patients with latent obstruction and 80 (92.0%) with resting obstruction achieved optimal procedural success, which was defined as a maximal gradient (after provocation) <30 mmHg and mitral regurgitation ≤ grade 1+ without mortality. Maximal left ventricular outflow tract gradient, basal septum thickness, midventricular wall thickness, mitral regurgitation grade and left atrial chamber size were significantly decreased after TA-BSM. In the follow-up, the New York Heart Association class was significantly improved following surgery.

CONCLUSIONS

TA-BSM preserved favourable gold-standard guideline desired outcomes through real-time echocardiographic-guided resection. Equipoise of outcomes for this procedure regardless of degree of resting left ventricular outflow tract gradients supports operative management with this approach in symptomatic patients with latent obstruction.

Adding Surgical Edge-to-Edge Mitral Valve Repair to Myectomy in Hypertrophic Obstructive Cardiomyopathy: Long-Term Functional and Echocardiographic Outcome

This study evaluates the early and long-term clinical and echocardiographic outcome of edge-to-edge (E2E) mitral valve repair (MVr) concomitant to septal myectomy (SM) in patients with symptomatic hypertrophic obstructive cardiomyopathy (HOCM). A retrospective single-center analysis was performed of patients who underwent isolated SM or SM with E2E MVr from 2011 to 2022. Exclusion criteria were primary mitral valve (MV) disease or concomitant valve surgery. Early and long-term safety, functional and echocardiographic outcomes were compared between groups. Between January 2011 and April 2022, 76 consecutive patients underwent SM for HOCM: 42 patients (55%) underwent SM without additional E2E MVr (Group 1) and 34 patients (45%) underwent SM with additional E2E MVr (Group 2). At latest follow-up, 87% of patients were in New York Heart Association (NYHA) class I-II with no significant differences in NYHA class between groups. Incidence of safety events was comparable between groups. Echocardiographic relief of left ventricular outflow tract (LVOT) obstruction was comparable at early follow-up (P = 0.68), with a significant but small difference in maximum LVOT pressure gradient at latest follow-up in favor of E2E MVr (P = 0.04). Furthermore, patients who underwent SM with E2E MVr showed less residual systolic anterior motion at early and latest follow-up (P = 0.020; P = 0.178). Reintervention on the MV was absent in both groups at 1 year and equally low at follow-up (P = 0.27). This study demonstrates that adding E2E MVr to septal myectomy is as safe as isolated myectomy for the treatment of HOCM. Moreover, the addition of E2E MVr is associated with similar excellent functional improvement and freedom from MV reintervention.

A systematic review of present and future pharmaco-structural therapies for hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a common contemporary, treatable, genetic disorder that can be compatible with normal longevity. While current medical therapies are ubiquitous, they are limited by a lack of solid evidence, are often inadequate, poorly tolerated, and do not alter the natural disease course. As such, there has long been a need for effective, evidence-based, and targeted disease-modifying therapies for HCM. In this review, we redefine HCM as a treatable condition, evaluate current strategies for therapeutic intervention, and discuss novel myosin inhibitors. The majority of patients with HCM have elevated left ventricular outflow tract gradients, which predicts worse symptoms and adverse outcomes. Conventional pharmacological therapies for symptomatic HCM can help improve symptoms but are often inadequate and poorly tolerated. Septal reduction therapies (surgical myectomy and alcohol septal ablation) can safely and effectively reduce refractory symptoms and improve outcomes in patients with obstructive HCM. However, they require expertise that is not universally available and are not without risks. Currently, available therapies do not alter the disease course or the progressive cardiac remodeling that ensues, nor subsequent heart failure and arrhythmias. This has been regarded as an unmet need in the care of HCM patients. Novel targeted pharmacotherapies, namely cardiac myosin inhibitors, have emerged to reverse key pathophysiological changes and alter disease course. Their favorable outcomes led to the early Food and Drug Administration approval of mavacamten, a first-in-class myosin modulator, changing the paradigm for the pharmacological treatment of HCM.

Valvular heart disease and cardiomyopathy: reappraisal of their interplay

Cardiomyopathies and valvular heart diseases are typically considered distinct diagnostic categories with dedicated guidelines for their management. However, the interplay between these conditions is increasingly being recognized and they frequently coexist, as in the paradigmatic examples of dilated cardiomyopathy and hypertrophic cardiomyopathy, which are often complicated by the occurrence of mitral regurgitation. Moreover, cardiomyopathies and valvular heart diseases can have a shared aetiology because several genetic or acquired diseases can affect both the cardiac valves and the myocardium. In addition, the association between cardiomyopathies and valvular heart diseases has important prognostic and therapeutic implications. Therefore, a better understanding of their shared pathophysiological mechanisms, as well as of the prevalence and predisposing factors to their association, might lead to a different approach in the risk stratification and management of these diseases. In this Review, we discuss the different scenarios in which valvular heart diseases and cardiomyopathies coexist, highlighting the need for an improved classification and clustering of these diseases with potential repercussions in the clinical management and, particularly, personalized therapeutic approaches.

Hypertrophic Cardiomyopathy: Preadolescence, Mitral Valve Disease, and Midventricular Obstruction

Septal myectomy is indicated in patients with obstructive hypertrophic cardiomyopathy (HCM) who have persistent symptoms despite medical therapy, intolerance of medication side effects, or severe resting or provocable gradients. Septal myectomy at high volume centers is safe, with low operative mortality (1%) and low rates of complications such as complete heart block or ventricular septal defect (3% and 0.5%, respectively). Additionally, improved survival following myectomy has been observed when compared to patients with obstructive HCM managed medically or those with nonobstructive HCM. As a longstanding, quaternary referral center for septal myectomy, our institution has built significant experience and expertise in the surgical and medical management of HCM, including atypical HCM, defined as preadolescent patients, those with mitral valve disease, and those with isolated midventricular obstruction. The most important factor of septal myectomy in achieving complete resolution of obstruction and avoiding recurrence is the apical extent of the myectomy trough, which must extend to the septum opposite the papillary muscles. If this cannot be fully achieved via a transaortic exposure, especially in preadolescents and patients with midventricular obstruction, then a transapical approach may be needed. Mitral valve repair is rarely necessary as SAM-mediated MR resolves with adequate myectomy alone, but mitral repair is performed in cases of intrinsic valvular disease. In this manuscript we provide a summary of current operative techniques and outcomes data from our institution on the management of these various categories of HCM.

Management of the mitral valve in thoracoscopic trans-mitral myectomy for hypertrophic obstructive cardiomyopathy

Objective

This study aimed to compare clinical outcomes of different mitral valve (MV) management methods in thoracoscopic transmitral myectomy (TTM) and guide surgeons' decision making for hypertrophic obstructive cardiomyopathy (HOCM).

Methods

Seventy-three consecutive patients (41 females; mean age, 53.7 ± 13.6 years) with HOCM who underwent TTM between January 2019 and October 2022 were enrolled and divided into 3 groups according to MV surgical strategy. Clinical outcomes were analyzed and compared among the groups.

Results

None of the patients experienced postoperative residual left ventricular outflow tract obstruction. Percentages of patients with mitral regurgitation (MR) grade ≥3+ (57.5% vs 1.4%) and systolic anterior motion (95.9% vs 2.7%) were significantly decreased postoperatively (P < .001 for both). The preoperative anterior mitral leaflet length was longer in patients in the anterior mitral leaflet direct reattachment group (median, 2.9 cm [interquartile range (IQR), 2.7-3.3 cm] vs 2.7 [IQR, 2.4-2.9 cm]; P = .018), but the postoperative coaptation length was shorter (mean, 8.3 ± 2.1 mm vs 11.1 ± 3.8 mm; P = .038). After a median echocardiography follow-up of 11.8 months, the left ventricular outflow tract gradient (LVOTG) and mitral regurgitation grades remained significantly improved in all 3 groups (P < .05 for all).

Conclusions

Total TTM in selected patients is safe and effective, and all 3 MV management strategies can significantly reduce the LVOTG while improving MR. Mitral valvuloplasty is the preferred initial management strategy over valve replacement except in the scenario of irreparable intrinsic MV disease and valvuloplasty failure.

Mitral annular calcification in obstructive hypertrophic cardiomyopathy: Incidence, risk factors, and prognostic value after myectomy

BACKGROUND

Mitral annular calcification (MAC) is a risk factor for cardiac surgery, but there is limited study on the prognosis value and the impact for valve function of MAC based on computed tomography (CT) diagnosis after myectomy for hypertrophic obstructive cardiomyopathy (OHCM).

METHODS

Consecutive OHCM patients underwent septal myectomy were compared according to the existence of MAC and its severity in preoperative CT scans. The survival data were evaluated and compared by Kaplan Meier analysis and log rank test. Cox regression analysis was used to evaluate the impact of MAC on endpoint events.

RESULTS

From the entire cohort of 1035 patients, 10.8% had MAC. In multivariate regression, female (OR = 2.23), age (OR = 1.07), aortic annular calcification (OR = 2.52), aortic calcification (OR = 2.56), systolic anterior motion of the mitral valve (SAM) (OR = 0.42), mitral valve thickening (OR = 2.13), and tricuspid regurgitation (OR = 3.12) were independent predictors of MAC. All-cause mortality (3.57% vs. 1.08%, p = 0.031), major adverse cardiovascular and cerebrovascular events (MACCE) (23.32% vs. 13.65%, p = 0.014), recurrent MR > 2+ (8.04% vs. 2.49%, p = 0.001) and NYHA III-IV (11.61% vs. 5.53%, p = 0.012) were more frequent in OHCM patients with MAC after myectomy. MAC was discovered to be an independent predictor of postoperative recurrent MR > 2+ after other risk factors were taken into account (HR 2.47, 95% CI 1.08-5.67, p = 0.0329). Moderate-to-severe MAC was an independent risk factor (HR 2.03, 95% CI 1.09-3.75, p = 0.0244) for long-term major adverse cardiovascular and cerebrovascular events (MACCE).

CONCLUSION

MAC was detected in one-tenth of OHCM patients in preoperative CT scanning and is mainly associated with aging and atherosclerosis. OHCM patients with MAC had a worse prognosis and more recurrent mitral valve regurgitation than those without MAC after septal myectomy.

Mitral Valve Prolapse in Obstructive Hypertrophic Cardiomyopathy

Obstructive hypertrophic cardiomyopathy (oHCM) and mitral valve (MV) prolapse (MVP) are the 2 conditions which could cause symptomatic heart failure and sudden cardiac death. The clinical characteristics and surgical outcomes of patients with oHCM and MVP have not been well reported. From April 2012 to February 2018, 84 patients with oHCM (28 patients with MVP and 56 gender- and age-matched patients without MVP) who underwent septal myectomy at our institution were enrolled in this study. Information on clinical characteristics and outcomes was obtained from electronic medical records and follow-up surveys. Compared with those without MVP, patients with MVP were more symptomatic (New York Heart Association class III to IV; 96% vs 77%), more often moderate-to-severe mitral regurgitation (86% vs 48%), atrial fibrillation (39% vs 11%) and higher incidence of nonsustained ventricular tachycardia (44% vs 15%). Twenty (71%) had MV repair and 8 (29%) had MV replacement. Compared with patients without MVP, those with MVP had a longer postoperative hospital stay (10.9 ± 6.4 vs 7.8 ± 2.8 days). None of the 84 study patients died during hospital or follow-up. At the most recent echocardiographic evaluation, left ventricular outflow tract gradient significantly decreased from 69.7 ± 35.4 millimeters of mercury to 7.3 ± 5.1 millimeters of mercury and the degree of mitral valve regurgitation improved from grade 2.43 ± 0.69 to grade 0.5 ± 0.69. In conclusion, MVP occurs rarely in oHCM, and was related to atrial fibrillation, ventricular arrhythmia and mitral regurgitation. Mitral valve surgery in combination with myectomy is effective and safe for patients with oHCM and MVP, relieving substantially left ventricular outflow tract gradients and mitral regurgitation.

Surgical Outcomes of Septal Myectomy With and Without Mitral Valve Surgeries in Hypertrophic Cardiomyopathy: a National Propensity-Matched Analysis (2005 to 2020)

The management of concomitant mitral valve (MV) disease in patients with hypertrophic cardiomyopathy (HCM) remains controversial. The 2020 American Heart Association/American College of Cardiology HCM guidelines recommend that MV replacement (MVR) at the time of myectomy should not be performed for the sole purpose of relieving outflow obstruction. At the national level, limited data exist on the surgical outcomes of MV repair/replacement in patients with HCM who underwent septal myectomy (SM). Hospitalizations of patients with HCM who underwent SM between 2005 and 2020 were identified using International Classification of Diseases, Ninth and Tenth Revision codes (International Classification of Diseases, Ninth and Tenth Revision Clinical Modification/Procedure Coding System). The 3 comparison cohorts were SM alone, MV repair, and MVR with concomitant SM. After propensity matching, 2 cohorts, SM + MVR versus SM + MV repair, were studied for surgical outcomes. Demographic characteristics, baseline co-morbidities, procedural complications, inpatient mortality, length of stay, and cost of hospitalization were compared between the propensity-matched cohorts. A total of 16,797 SM procedures were identified from 2005 to 2020. Among them, 11,470 hospitalizations had SM alone (68.2%), SM + MVR was seen in 3,101 (18.4%), and SM + MV repair comprised 2,226 (13.2%). After propensity matching, the MVR and MV repair formed the matched cohorts of 1,857. There were no significant differences in the odds of cardiogenic shock (adjusted odds ratio [aOR] 0.88, 95% confidence interval [CI] 0.63 to 1.24, p = 0.49), mechanical circulatory support requirement (aOR 0.58, 95% CI 0.37 to 0.90, p = 0.015), stroke (aOR 1.27, 95% CI 0.81 to 1.99, p = 0.29), and major bleeding (aOR 0.52, 95% CI 0.34 to 0.79, p = 0.0026) between the comparison groups. MVR, compared with MV repair, was associated with a higher risk of procedural mortality (8.02% vs 3.18%, aOR 2.98, 95% CI 2.05 to 4.33, p <0.0001), complete heart block (16.36% vs 12.15%, aOR 1.76, 95% CI 1.44 to 2.12, p <0.0001), and the need for permanent pacemaker (16.39% vs 10.62%, aOR 1.83, 95% CI 1.41 to 2.38, p <0.0001). The total length of hospital stay and median hospitalization cost was higher in the MVR group. SM in HCM concomitant with MVR is associated with higher procedural mortality and in-hospital complication risk. These real-world data support the 2020 American Heart Association/American College of Cardiology guidelines that in patients who are candidates for surgical myectomy, MVR should not be performed as part of the operative strategy for relieving outflow obstruction in HCM.

Septal Myectomy Outcomes in Children and Adolescents With Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

Little data exist regarding characteristics and outcomes of pediatric patients undergoing septal myectomy. We evaluated this in a large referral population.

METHODS

Septal myectomy was performed in 199 consecutive patients aged ≤18 years with obstructive hypertrophic cardiomyopathy from January 1, 1976, to June 30, 2021.

RESULTS

Median age was 13 years (interquartile range [IQR], 8-15 years). Left ventricular myectomy approaches included transaortic (163 of 198 [82%]), transapical (16 of 198 [8%]), and combined (19 of 198 [10%]). Right ventricular interventions included myectomy (13 of 199 [7%]) and patch reconstruction of the outflow tract (15 of 199 [8%]). Maximum left ventricular outflow tract gradients decreased after myectomy (prebypass: 50 mm Hg [IQR, 31-73 mm Hg] vs postbypass: 4 mm Hg [IQR, 0-9 mm Hg], P < .001), and this was sustained long-term (5 mm Hg [IQR, 5-10 mm Hg] at 10 years). Iatrogenic aortic and mitral valve injuries occurred in 13 of 199 (7%) and 1 of 199 (1%), respectively; however, all were successfully repaired. Operative mortality was 2 of 199 (1%). The cumulative incidence of redo myectomy was low, at 5.8% at 5 and 8.3% at 10 years. Redo myectomy patients had higher maximum left ventricular outflow tract gradients on echocardiography at predischarge and 1 year and were younger at the index operation (8 years [IQR, 2.5-10 years] vs 13 years [IQR, 9-16 years], P < .001). Overall survival at 10 years was 90%, relative to 47% in a previously reported pediatric nonoperative cohort.

CONCLUSIONS

Pediatric septal myectomy provides safe, effective, and durable relief of ventricular outflow tract obstruction. Iatrogenic valve injury remains a low but nonnegligible risk. Recurrent obstruction requiring redo myectomy is infrequent and can be identified early. Long-term survival in this pediatric septal myectomy cohort appears to fare better than pediatric hypertrophic cardiomyopathy cohorts managed nonoperatively.

First-in-Human Transapical Beating-Heart Septal Myectomy in Patients With Hypertrophic Obstructive Cardiomyopathy

BACKGROUND

To simplify surgical septal reduction therapy for hypertrophic obstructive cardiomyopathy (HOCM), we developed a novel transapical beating-heart septal myectomy (TA-BSM) procedure.

OBJECTIVES

In this study, we sought to evaluate the clinical utility of TA-BSM in a first-in-human trial.

METHODS

Patients with HOCM were enrolled if they presented with drug-refractory disabling symptoms. TA-BSM was performed via minithoracotomy with the use of our beating-heart myectomy device under echocardiographic guidance, without the use of cardiopulmonary bypass. Repeated resections were performed to tailor the extent of the septal myectomy for sufficient abolishment of left ventricular outflow tract (LVOT) obstruction and mitral regurgitation (MR). The primary outcome measure was procedural success, defined by resting/provoked LVOT gradient <30/50 mm Hg and residual MR grade ≤1+ (of 4+) at 3-month follow-up.

RESULTS

A total of 47 patients aged 12 to 77 years were enrolled. Of the 46 patients who were followed for 3 months, 42 achieved procedural success. The maximal LVOT gradient decreased from 86 mm Hg (IQR: 67-114 mm Hg) at baseline to 19 mm Hg (IQR: 14-28 mm Hg) at 3 months. MR grade was ≤1+ in 3 patients at baseline and in 45 patients at 3 months. One patient died on postoperative day 10 owing to device-unrelated reasons. Other major adverse events included 1 delayed ventricular septal perforation and 1 intraoperative left ventricular apical tear.

CONCLUSIONS

TA-BSM is a safe and efficient minimally invasive procedure for septal reduction of heterogeneous HOCM. Compared with conventional septal myectomy, TA-BSM provides real-time evaluation to guide resection while reducing surgical trauma. (Transapical Beating-Heart Septal Myectomy in Patients With Hypertrophic Obstructive Cardiomyopathy; NCT05332691).

Volume-outcome relationship in septal myectomy for hypertrophic obstructive cardiomyopathy

BACKGROUND

Septal myectomy is the gold standard treatment for refractory hypertrophic obstructive cardiomyopathy. The present study characterized the association of septal myectomy volume and cardiac surgery volume with outcomes after septal myectomy.

METHODS

Adults undergoing septal myectomy for hypertrophic obstructive cardiomyopathy were identified in the 2016 to 2019 Nationwide Readmissions Database. Centers were grouped into low-, medium-, and high-volume hospitals by tertiles based on institutional septal myectomy caseload. Overall cardiac surgery volume was similarly assessed. Generalized linear models were used to test the association between hospital septal myectomy or cardiac surgery volume and in-hospital mortality, mitral valve repair, and 90-day non-elective readmission.

RESULTS

Of 3,337 patients, 30.8% underwent septal myectomy at high-volume hospitals, whereas 39.1% were managed at low-volume hospitals. Patients at high-volume hospitals had a similar burden of comorbidities at low-volume hospitals, although congestive heart failure was more prevalent at high-volume hospitals. Despite comparable rates of mitral regurgitation, patients more commonly avoided mitral valve intervention at high-volume hospitals compared with low-volume hospitals (72.9% vs 68.3%; P = .007). After risk adjustment, high-volume hospital status was associated with reduced odds of mortality (0.24; 95% CI, 0.08-0.77) and readmission (0.59; 95% CI, 0.3-0.97). Among cases requiring mitral intervention, high-volume hospital status was associated with greater odds of valve repair (5.33; 95% CI, 2.54-11.13) relative to low-volume hospitals. Overall cardiac surgery volume was not associated with any studied outcome.

CONCLUSION

Greater septal myectomy volume, but not overall cardiac surgery volume, was associated with reduced mortality and greater mitral valve repair relative to replacement after septal myectomy. These findings suggest that septal myectomy for hypertrophic obstructive cardiomyopathy should be performed at centers with expertise in this operation.

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.

[Mitral valve replacement in patients with obstructive hypertrophic cardiomyopathy]

OBJECTIVE

To analyze the incidence and causes of mitral valve replacement in patients with obstructive hypertrophic cardiomyopathy (HCM).

MATERIAL AND METHODS

There were 172 patients (98 women and 74 men) with obstructive HCM and severe mitral valve insufficiency between November 2017 and May 2023. All patients complained of chronic heart failure NYHA class III. Surgical correction of left ventricular outflow tract (LVOT) obstruction and mitral valve repair with elimination of systolic anterior motion were technically successful in 160 (93.0%) patients.

RESULTS

The need for mitral valve replacement was noted in 12 (7.0%) patients. Mean cardiopulmonary bypass time was 83.5±19.2 min (94; 127), aortic cross-clamping - 62.8±14.3 min (70; 102). In 5 cases, primary mitral valve replacement was scheduled due to obvious organic lesion of the mitral valve (tearing of chords, rheumatic lesion with leaflet restriction). In 7 patients, valve replacement was forced after ineffective primary septal myectomy (LVOT pressure gradient, severe mitral insufficiency).

CONCLUSION

Mitral valve replacement is an involuntary strategy after ineffective myectomy with severe mitral insufficiency and high LVOT pressure gradient.

Impact of Hospital Volume on Outcomes of Septal Myectomy for Hypertrophic Cardiomyopathy

BACKGROUND

Left ventricular outflow tract obstruction is common among symptomatic patients with hypertrophic cardiomyopathy, yet septal reduction by surgical myectomy (septal myectomy [SM]) is performed infrequently in many centers. This study examined the possible relationship between institutional case volume and early outcomes of SM.

METHODS

The Society of Thoracic Surgeons Adult Cardiac Surgery Database was queried for patients with hypertrophic cardiomyopathy who underwent SM from January 2012 to December 2019. The study defined center case volume categories as <1, 1 to 4.99, 5 to 9.99, and ≥10 cases performed on average per year.

RESULTS

The study population included 5935 patients at 481 centers with 933 surgeons. The range of average center volume was <1 to 138 cases per year. Overall early mortality was 2.6%, ventricular septal defect (VSD) occurred in 1.9%, and complete heart block occurred in 9.0%. Concomitant mitral valve (MV) repair was performed in 28.7%, and MV replacement was performed in 17.1%. In multivariable analysis, the lowest annual case volume (average <1 case/y) was consistently associated with greater early mortality (odds ratio [OR], 5.4; CI, 3.0-9.9; P < .001), greater risk of VSD (OR, 9.3; CI ,4.2-20.4; P < .001), increased incidence of complete heart block (OR, 2.0; CI, 1.5-2.7; P < .001), and a higher likelihood of MV replacement (OR, 9.4; CI, 7.5-11.8; P < .001).

CONCLUSIONS

Volume of SM cases varies widely among institutions reporting to the Society of Thoracic Surgeons Adult Cardiac Surgery Database. There appears to be an important association between surgical experience, as reflected by institutional case volume, and early outcomes, including mortality, as well as the occurrence of VSD, heart block, and MV replacement.

Primeval outcomes of thoracoscopic transmitral myectomy with anterior mitral leaflet extension for hypertrophic obstructive cardiomyopathy

BACKGROUND

The transaortic Morrow procedure is the current gold standard for hypertrophic obstructive cardiomyopathy (HOCM) patients who are resistant to maximum drug therapy. It is controversial whether concomitant mitral valve intervention is necessary. Only a few centers apply for concomitant anterior mitral leaflet extension with a bovine or autologous pericardial patch to further decrease systolic anterior motion. Our aim is to assess the primeval outcomes of thoracoscopic transmitral myectomy with anterior mitral leaflet extension (TTM-AMLE) in symptomatic HOCM patients.

METHODS

Between April 2019 and November 2020, 18 consecutive HOCM patients who underwent TTM-AMLE were enrolled in this study. Preoperative, postoperative, and follow-up outcomes were compared and statistically analyzed.

RESULTS

The mean age was (50.17 ± 6.18) years and 10 (55.56%) were males. 18 (100%) patients had mitral regurgitation preoperatively, and they all successfully underwent TTM-AMLE with a median cardiopulmonary bypass and aortic cross-clamp time of 200.0 (150.8, 232.0), and 127.5 (116.0, 149.0) min, respectively. The median length of ICU stay was 2.7 (1.4, 5.2) days. The interventricular septum thickness was significantly reduced (from 18.03 ± 3.02 mm to 11.91 ± 1.66 mm, p < .001). There was no perioperative mortality, perforation of ventricular septum, or conversion to sternotomy observed. During a median follow-up of 18 months (IQR, 5-24 months), 1 (5.56%) patient had severe mitral regurgitation due to patch detachment and received reoperation. Moderate degree of mitral regurgitation and more than 50 mmHg in left ventricular outflow tract gradient were found in 2 (11.11%), and 1 (5.56%) patients, respectively. 1 (5.56%) patient who had second-degree atrioventricular block received permanent pacemaker implantation postoperatively. Overall, the maximum left ventricular outflow tract gradient (88.50 [59.50, 112.75] mmHg vs. 10.50 [7.00, 15.50] mmHg, p = .002), left ventricular outflow tract velocity (4.70 [3.86, 5.33] m/s vs. 1.60 [1.33, 1.95] m/s, p < .001) and the degree of mitral regurgitation (6.99 ± 4.47 cm² vs. 2.22 ± 1.51 cm² , p = .001) were significantly decreased, with a significant reduction in the proportion of systolic anterior motion (94.44% vs. 16.67%, p < .001).

CONCLUSIONS

The TTM-AMLE is a safe and effective surgical approach for selected patients with HOCM. In our series, it provides excellent relief of left ventricular outflow tract obstruction, while significantly eliminating mitral regurgitation. The early outcomes of TTM-AMLE are satisfactory, but further studies and longer follow-ups are awaited.

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

•

Hypertrophic cardiomyopathy is a common genetic heart disease.

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Patients can have variable clinical manifestations and severity of disease.

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Manifestations include LVOT obstruction and MR.

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Alcohol septal ablation can successfully treat LVOT obstruction and MR.

Systolic anterior motion of the mitral valve in hypertrophic cardiomyopathy: a narrative review

Background and Objective

The prevalence of hypertrophic cardiomyopathy (HCM) is estimated to be 1 in 200 to 500 individuals, with systolic anterior motion (SAM) of the mitral valve (MV) and left ventricular outflow tract (LVOT) obstruction present in 60% to 70%. In this narrative review, we aim to elucidate the pathophysiology of SAM-septal contact and LVOT obstruction in HCM by presenting a detailed review on the anatomy of the MV apparatus in HCM, examining the various existing theories pertaining to the SAM phenomenon as supported by cardiac imaging, and providing a critical assessment of management strategies for SAM in HCM.

Methods

A literature review was performed using PubMed, EMBASE, Ovid, and the Cochrane Library, of all scientific articles published through December 2021. A focus was placed on descriptive studies, reports correlating echocardiographic findings with pathologic diagnosis, and outcomes studies.

Key Content and Findings

The pathophysiology of SAM involves the complex interplay between HCM morphology, MV apparatus anatomic abnormalities, and labile hemodynamic derangements. Echocardiography and cardiac magnetic resonance (CMR) vector flow mapping have identified drag forces, as opposed to the "Venturi effect", as the main hydraulic forces responsible for SAM. The degree of mitral regurgitation with SAM is variable, and its severity is correlated with degree of LVOT obstruction and outcomes. First line therapy for the amelioration of SAM and LVOT obstruction is medical therapy with beta-blockers, non-dihydropyridine calcium-channel blockers, and disopyramide, in conjunction with lifestyle modifications. In refractory cases septal reduction therapy is performed, which may be combined with a 'resect-plicate-release' procedure, anterior mitral leaflet extension, surgical edge-to-edge MV repair, anterior mitral leaflet retention plasty, or secondary chordal cutting.

Conclusions

Recent scientific advances in the field of HCM have allowed for a maturation of our understanding of the SAM phenomenon. Cardiac imaging plays a critical role in its diagnosis, treatment, and surveillance, and in our ability to apply the appropriate therapeutic regimens. The increasing prevalence of HCM places an emphasis on continued basic and clinical research to further improve outcomes for this challenging population.

Transmitral Septal Myectomy and Mitral Valve Surgery via Right Mini-Thoracotomy

Background Transmitral myectomy for symptomatic hypertrophic obstructive cardiomyopathy is possible with existence of substantial mitral valve disease. We present herein our experience of minimally invasive transmitral septal myectomy combined with mitral valve surgery through right anterior mini-thoracotomy in the past 4 years at our institution.

Methods Between March 2017 and October 2020, 14 patients with hypertrophic obstructive cardiomyopathy and mitral valve disease required minimally invasive transmitral septal myectomy combined with mitral valve reconstruction or replacement at our institution. Mean age of patients was 54.2 ± 11.4 and 42.9% (n = 6) were female. Twelve patients (85.1%) were in New York Heart Association class III to IV and 6 patients (42.9%) presented with persistent atrial fibrillation. Clinical data were prospectively entered into our institutional database.

Results Cardiopulmonary bypass time accounted for 140.2 ± 32.6 minutes and the myocardial ischemic time was 78.5 ± 12.4 minutes. Thirty-day mortality and overall mortality were zero. Peak ventricular outflow gradient decreased from 75.2 ± 12.7 to 9.4 ± 2.3 mm Hg (p < 0.0001). Simultaneously, mitral valve reconstruction and replacement were performed in 11 (78.6%) and 3 (21.4%) patients, respectively. No systolic anterior motion was seen in patients with mitral valve repair. No conversion to full sternotomy and/or rethoracotomy was noted. During a mean follow-up period of 24 ± 13 months, no patient required reoperation, no recurrence mitral regurgitation, and left ventricular outflow tract obstruction.

Conclusion Transmitral septal myectomy combined with mitral valve surgery through right anterior mini-thoracotomy can be performed safely with excellent surgical outcomes.

Optimal Management of Mitral Regurgitation Due to Ruptured Mitral Chordae Tendineae in Patients With Hypertrophic Cardiomyopathy

There is continued controversy regarding surgical management of patients with hypertrophic cardiomyopathy (HCM) and intrinsic mitral valve disease; some clinicians favor prosthetic replacement as this corrects left ventricular outflow tract (LVOT) obstruction and valve leakage. In this study, we investigated the management and late outcome of operation for mitral regurgitation (MR) due to ruptured chordae tendineae in patients with HCM. We analyzed 49 consecutive patients with HCM and MR due to ruptured mitral valve chordae. Echocardiograms and operative reports were reviewed to classify valve anatomy and surgical methods. Information on late outcomes was obtained from electronic medical records and follow-up surveys. The mean age of the 36 men and 13 women was 61.9 ± 12.5 years; significant resting or provoked LVOT obstruction was present at the time of surgery in 46 patients. During the index operation, mitral valve repair was performed in 45 patients, and prosthetic replacement was necessary for 4 patients. Concomitant septal myectomy was performed in 46 patients. There were no hospital deaths or deaths within 30 days of operation. Five and ten-year survival estimates (Kaplan-Meier) were 92% and 71%. During follow-up at a median of 7.9 years, 3 patients underwent reoperation for MV replacement, 5 days, 3 years, and 14 years following valve repair. Ruptured mitral chordae may result in severe mitral valve regurgitation in patients with hypertrophic cardiomyopathy. Valvuloplasty at the time of septal myectomy is safe with an acceptably low rate of recurrent MR requiring prosthetic replacement.

Post-operative management of hypertrophic obstructive cardiomyopathy

Hypertrophic obstructive cardiomyopathy patients are at increased risk of sudden cardiac arrest due to dynamic left ventricular outflow tract obstruction, myocardial ischaemia and arrhythmias. Septal myectomy remains the gold standard therapy for patients with hypertrophic obstructive cardiomyopathy (HOCM) refractory to other therapy. This review comprehensively focuses on the post-operative management and complications of HOCM patients undergoing surgical correction. Although these patients are at risk of various perioperative complications from anaesthesia and surgery due to the underlying complexity of their disease, surgical myectomy is associated with excellent long-term outcomes if carried out in experienced centers.

Mitral Annular Calcification in Obstructive Hypertrophic Cardiomyopathy: Prevalence and Outcomes

BACKGROUND

The prevalence and clinical impact of mitral annular calcification (MAC) in patients with obstructive hypertrophic cardiomyopathy (HCM) are largely unknown.

METHODS

We reviewed 2113 HCM patients who underwent septal myectomy from January 2000 to April 2016. Preoperative and intraoperative echocardiograms along with operative notes were reviewed to identify MAC. Survival was estimated and compared using Kaplan-Meier analysis and log-rank test. Cox regression analysis was used to identify factors independently associated with mortality.

RESULTS

MAC was identified in 390 (18.5%) patients. Older age, female sex, and presence of mitral valve leaflet calcification were strongly associated with higher odds of having MAC. Patients with MAC had higher resting LVOT gradients, more likely to have worse mitral valve regurgitation (MR) preoperatively, and more likely to undergo a concomitant mitral valve replacement (6% vs 1%, P<0.001) compared to those without MAC. Postoperatively, patients with MAC had marginally higher residual MR (13% vs 8%). After a median follow-up of 6.95 (IQR 3.7- 12.1) years, survival of patients with MAC at 1, 5 and 10 years was 99%, 92% and 69% respectively. Adjusted analysis identified MAC as an independent predictor of poor survival (HR 1.46, 95% CI 1.08 to 1.97; P=.014).

CONCLUSIONS

MAC is a frequent finding in older patients with obstructive HCM, more likely to be seen in females, and is associated with higher rates of concomitant mitral valve replacement. Despite higher prevalence of comorbidities, MAC remained an independent predictor for overall mortality following septal myectomy.

Early post-septal myectomy outcomes for hypertrophic obstructive cardiomyopathy

BACKGROUND

We aimed to evaluate early outcomes of septal myectomy in patients with hypertrophic cardiomyopathy.

METHODS

We retrospectively analyzed data collected over a 9-year period from 583 patients who underwent septal myectomy for hypertrophic cardiomyopathy at our institution.

RESULTS

The mean age was 55.7 ± 13.1 years, and 338 (58%) patients were in New York Heart Association class III or IV. There were 11 (1.9%) early deaths, including 3 (0.5%) intraoperative deaths. Early mortality was lowest after isolated septal myectomy (0.8%) and highest after concomitant mitral valve replacement (6.1%). There were 4 (0.7%) and 9 (1.5%) patients with left ventricular wall rupture and ventricular septal defect, respectively, after myectomy. New pacemaker implantation caused by atrioventricular disturbances was required in 29 (5.0%) patients, and was associated with previous alcohol septal ablation (odds ratio 3.34, 95% confidence interval 1.02-11.0, P = 0.047). Left ventricular wall rupture, intraoperative residual (15.5% moderate, 0.3% severe) mitral regurgitation, and pre-discharge residual outflow tract gradient >30 mm Hg (4.6%) occurrences were surgeon-dependent.

CONCLUSIONS

The early results are consistent with example targets reported in the 2020 American College of Cardiology/American Heart Association guidelines for septal reduction therapy outcomes. Septal myectomy safety and efficacy are surgeon-dependent. Previous alcohol septal ablation increases the risk of permanent pacemaker implantation due to postoperative complete atrioventricular block. Therefore, continuous education, mentoring, and learning by doing may play an important role in achieving reasonable septal myectomy safety and efficacy.

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.

Prognostic implications of different clinical profiles in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a myocardial genetic disease relatively common in the general population with heterogenous clinical presentation, natural history and prognosis. About 60% of HCM patients have a stable clinical course, while others may experience a variety of HCMrelated complications which follows relatively independent pathways, and that can be distinguished in different subgroups. These subgroups are represented by patients with left ventricular outflow tract obstruction; patients with end-stage disease and reduced or preserved systolic function; patients with apical hypertrophy; patients with apical aneurysm; patients with atrial fibrillation, patients at high risk of sudden death and patients with pre-clinical HCM. The purpose of this review is to describe each of these clinical profiles with its prognostic implications.

Comparison of mitral regurgitation severity assessments based on magnetic resonance imaging and echocardiography in patients with hypertrophic cardiomyopathy

Mitral regurgitation (MR), which is one of the factors responsible for heart failure symptoms and the development of atrial fibrillation, is an important feature of hypertrophic cardiomyopathy (HCM), and its presence affects which treatment options are chosen. Although cardiac magnetic resonance imaging (MRI) is considered the reference standard for assessing the regurgitant volume (RV) and fraction (RF), echocardiography is the most common method for assessing MR severity. Accordingly, the aim of this study was to compare the results of echocardiography and cardiac MRI for assessing MR severity in a cohort of patients with HCM. MR severity was assessed in 53 patients using cardiac MRI by determining the mitral RV (MRV) and mitral RF (MRF). The results were graded according to thresholds recommended in current guidelines. MR severity assessed by echocardiography was graded by integrating indices of severity. Greater than mild MR, as assessed using echocardiography, was present in 22 patients (41.5%) with HCM and in none of the control patients (p = 0.001). In all, 31 patients (58.5%) had no more than mild MR. When MR severity was assessed using different methods, either moderate (kappa = 0.44, 95% confidence interval = 0.21–0.67), poor or no agreement was found between MRI-derived and echocardiography-derived grades. HCM patients with echocardiography-derived moderate and severe MR had similar median MRVs and MRFs (p = 0.59 and p = 0.11, respectively). In HCM patients, cardiac MRI and echocardiography were at most in modest agreement in assessing MR severity. Importantly, echocardiography-derived moderate and severe MR were not distinguishable by either MRV or MRF.

Echocardiographic evaluation of hypertrophic cardiomyopathy: A review of up-to-date knowledge and practical tips

Hypertrophic cardiomyopathy (HCM) is the most frequent cardiac disease with genetic substrate, affecting about .2%-.5% of the population. The proper diagnosis is important for optimal management and follow-up. Echocardiography plays an essential role in the assessment of patients with HCM including diagnosis, screening, management formulation, prognosis, and follow up. It also helps to differentiate HCM from other diseases. The advancement of software and probe technology added many echo modalities and techniques that helped in refining the diagnostic and assessing the prognosis of patients with HCM. In this review, we briefly summarize how to integrate the different echocardiographic modalities to obtain comprehensive assessment supported by an updated knowledge of the latest guidelines and recently published articles. Many practical tips and tricks are included in this review to improve the diagnostic accuracy of echocardiography and minimize errors during interpretation.

Hypertrophic cardiomyopathy with latent obstruction: Clinical characteristics and surgical results

BACKGROUND

The role of mitral subvalvular anomalies in the etiology of latent left ventricular outflow tract (LVOT) obstruction has rarely been reported; and the results of surgical treatment for latent LVOT obstruction have been infrequently reported as a separate group by other medical centers other than Mayo clinic.

METHODS

Among 292 eligible patients, 45 with resting gradients <30 mmHg had provoked obstruction. Their clinical characteristics and surgical results were compared with those of 247 patients with resting LVOT obstruction. The patients were followed up for a median of 13 months.

RESULTS

Comparatively, patients with latent obstruction were younger (51.6±12.1 years vs. 57.2±11.6 years, p=0.003) and had higher prevalence of mitral subvalvular abnormalities (73.3% vs. 16.2%, p<0.001) and basal variant of hypertrophic cardiomyopathy (84.5% vs. 62.0%, p=0.014), less marked septal thickness (16.9±2.8 mm vs. 18.6±3.8 mm, p=0.005), lower resting gradients (22.2±5.7 mmHg vs. 93.0±25.7 mmHg, p < 0.001), and lower mitral regurgitation severity (median, 2.0 vs. 3.0, p<0.001). After surgery, no surgical death occurred in patients with latent LVOT obstruction. Only one (2.2%) patient from the latent group developed complete atrioventricular block. No follow-up death or reoperation was recorded with a significant improvement in New York Heart Association functional status in either group. The provoked LVOT gradients of patients with latent obstruction decreased sharply from the preoperative value (11.8±3.7 mmHg vs. 89.8±16.4 mmHg, p < 0.001), with no occurrence of residual obstruction.

CONCLUSIONS

Symptomatic patients with latent LVOT obstruction may have a higher prevalence of mitral subvalvular abnormalities and have less marked septal hypertrophy; and concomitant mitral management during myectomy for the treatment of this patient group achieved excellent results.