Evolving Strategies for Management of Obstructive Hypertrophic Cardiomyopathy.

For many years, treatment of hypertrophic cardiomyopathy (HCM) has focused on non-disease specific therapies. Cardiac myosin modulators (i.e., mavacamten and aficamten) reduce the pathologic actin-myosin interactions that are characteristic of HCM, leading to improved cardiac energetics and reduction in hypercontractility. Several recently published randomized clinical trials have demonstrated that mavacamten improves exercise capacity, left ventricular outflow tract obstruction, and symptoms in patients with obstructive HCM (oHCM), and may delay the need for septal reduction therapy. Long-term data in real world populations will be needed to fully assess the safety and efficacy of mavacamten. Importantly, HCM is a complex and heterogeneous disease and not all patients will respond to mavacamten; therefore, careful patient selection and shared decision-making will be necessary in guiding the use of mavacamten in oHCM.

Mitral regurgitation mechanisms related to systolic anterior motion in hypertrophic cardiomyopathy.

Background: Systolic anterior motion (SAM) of the mitral valve can result in mitral regurgitation (MR) and adverse outcomes in patients with obstructive hypertrophic cardiomyopathy (HCM). However, the mechanism and characteristics of MR severity mediated by SAM are unresolved. This study aimed to elucidate the anatomic and hemodynamic associations of MR and the impact of septal myectomy on changes in MR severity in patients with HCM. Methods: We retrospectively reviewed patients who underwent septal myectomy with SAM and interpretable imaging between 2017-2022. Significant MR was defined as moderate or more MR. The mitral valve, papillary muscle, and left ventricular geometry were quantitatively evaluated via echocardiography and cardiac computed tomography. Results: Out of 34 patients, two groups were identified: those with preoperative significant MR (n=16) and those without significant MR (n=18). Patients with significant preoperative MR exhibited worse heart failure symptoms at baseline than those without. Following myectomy, these patients showed higher residual left ventricular outflow tract (LVOT) gradients at rest and with provocative measures than those without preoperative MR. Multivariate regression analysis revealed a significant association between the tenting area and MR severity. Additionally, the chordal cutting procedure alleviated the tenting area [2.1 (1.8-2.6) vs. 1.4 (1.2-1.6) cm2] compared to those without it. Conclusions: Our preliminary data suggested that chordal cutting with septal myectomy was associated with an improvement in the tenting area, contributing to MR severity. This procedure may serve as an effective therapy for patients with SAM and significant MR.

Advanced Heart Failure Therapies for Hypertrophic Cardiomyopathy: State-of-the-Art Review and an Updated Analysis From UNOS.

Hypertrophic cardiomyopathy (HCM) is most commonly associated with obstructive symptoms and sudden cardiac death; however, predominantly nonobstructive advanced heart failure in HCM, marked by medically refractory disease with severe functional impairment, occurs in 5% to 7% of patients with HCM. The diagnosis relies on the integration of imaging (echocardiography/cardiac magnetic resonance), hemodynamic data, and cardiopulmonary exercise testing to identify the patients who will benefit from advanced heart failure therapies. Most advanced heart failure therapies focus on systolic dysfunction and are not always applicable to this patient population. Left ventricular assist devices may be an option in a highly selected population with left ventricular dilation. Heart transplantation is often the best option for patients with advanced heart failure in HCM with excellent post-transplantation survival.

Effects of bariatric surgery on cardiovascular-related acute care use in patients with hypertrophic cardiomyopathy.

AIMS: Prior studies have suggested causal relationships between obesity and acute cardiovascular events. It has been also known that the risk of acute cardiovascular events is reduced by bariatric surgery. However, little is known about whether bariatric surgery lowers the risk of acute cardiovascular events in patients with obesity and hypertrophic cardiomyopathy (HCM). In this context, we aimed to investigate whether bariatric surgery is associated with a reduced risk of cardiovascular-related acute care use in patients with HCM. METHODS AND RESULTS: In this population-based study, the bariatric surgery group consisted of patients with HCM who underwent bariatric surgery from January 2004 to December 2014. The control group included those who have obesity and HCM and received non-bariatric elective intra-abdominal surgery during the same period. The outcome was cardiovascular-related acute care use (i.e. emergency department (ED) visits or unplanned hospitalizations for cardiovascular disease) during a 1-year post-surgery period. We used the SPARCS database, a population-based ED and inpatient database in New York State. We constructed logistic regression models with generalized estimating equations to compare the risk of the outcome events during sequential 6-month post-surgery periods. We adjusted for age, sex, number of ED visits and hospitalizations for cardiovascular disease within 2 years before the index surgery, and the Elixhauser co-morbidity measures. We also performed propensity score (PS)-matching and inverse probability treatment weighting analyses using these variables. The analytic cohort consisted of 207 adults with obesity and HCM, including 147 patients who underwent bariatric surgery and 60 in the control group. The risk was not significantly different in the 1-6 months post-surgery period. By contrast, in the 7-12 months post-surgery period, the risk of cardiovascular-related acute care use was significantly lower in the bariatric surgery group (adjusted odds ratio 0.23; 95% CI 0.068-0.71; P = 0.01) compared with the control group. In the PS-matched cohort, there were no significant differences in the baseline characteristics. The PS-matched analysis demonstrated lower risk of the outcome event in the bariatric surgery group in the 7-12 months post-surgery period. The inverse probability treatment weighting analysis replicated the findings. CONCLUSIONS: Bariatric surgery was associated with a lower risk of cardiovascular-related acute care use in the 7-12 months post-surgery period in this population-based study.

Left ventricular remodeling following septal myectomy in hypertrophic obstructive cardiomyopathy.

Objectives: The purpose of this study is to determine whether or not left ventricular remodeling can be induced after septal myectomy in patients with obstructive hypertrophic cardiomyopathy, and if so, how it occurs, using gated cardiac computed tomography. Methods: Fifty patients with hypertrophic obstructive cardiomyopathy who underwent septal myectomy along the septal band between March 2016 and July 2020 were retrospectively reviewed. Recent consecutive 19 patients underwent postoperative cardiac computed tomography. In these patients, volumes of the septal band and thickness of 17 left ventricular myocardial segments were measured to determine the changes after surgery. Results: The resection volume predicted by preoperative computed tomography and the actual resection volume were 6.7 ± 3.3 mL and 6.4 ± 2.7 mL. In-hospital mortality was 0%. Moderate or greater mitral valve regurgitation and systolic anterior motion decreased from 56% to 6% and 86% to 6%, respectively. Median preoperative ventricular septal thickness and left ventricular outflow tract pressure gradient at rest decreased from 20.0 mm (interquartile range, 17.0-24.0 mm) and 74.0 mm Hg (interquartile range, 42.5-92.5 mm Hg) to 14.0 mm (interquartile range, 11.5-16.0 mm) and 15.5 mm Hg (interquartile range, 12.1-21.5 mm Hg), respectively. Postoperative computed tomography confirmed a reduction in septal band volume of 5.7 ± 2.8 mL. Total left ventricular myocardial volume was reduced by 12.9 ± 8.8 mL, which exceeded the volume reduction of the resected septal band. All segments except the basal inferior and basal inferolateral regions showed a significant decrease in wall thickness by a median of 6.4%. Conclusions: Properly performed septal myectomy may induce remodeling of the entire left ventricle, not just the resected area.

Indications for and Findings on Transthoracic Echocardiography in COVID-19.

BACKGROUND: Despite growing evidence of cardiovascular complications associated with coronavirus disease 2019 (COVID-19), there are few data regarding the performance of transthoracic echocardiography (TTE) and the spectrum of echocardiographic findings in this disease. METHODS: A retrospective analysis was performed among adult patients admitted to a quaternary care center in New York City between March 1 and April 3, 2020. Patients were included if they underwent TTE during the hospitalization after a known positive diagnosis for COVID-19. Demographic and clinical data were obtained using chart abstraction from the electronic medical record. RESULTS: Of 749 patients, 72 (9.6%) underwent TTE following positive results on severe acute respiratory syndrome coronavirus-2 polymerase chain reaction testing. The most common clinical indications for TTE were concern for a major acute cardiovascular event (45.8%) and hemodynamic instability (29.2%). Although most patients had preserved biventricular function, 34.7% were found to have left ventricular ejection fractions ≤ 50%, and 13.9% had at least moderately reduced right ventricular function. Four patients had wall motion abnormalities suggestive of stress-induced cardiomyopathy. Using Spearman rank correlation, there was an inverse relationship between high-sensitivity troponin T and left ventricular ejection fraction (ρ = -0.34, P = .006). Among 20 patients with prior echocardiograms, only two (10%) had new reductions in LVEF of >10%. Clinical management was changed in eight individuals (24.2%) in whom TTE was ordered for concern for acute major cardiovascular events and three (14.3%) in whom TTE was ordered for hemodynamic evaluation. CONCLUSIONS: This study describes the clinical indications for use and diagnostic performance of TTE, as well as findings seen on TTE, in hospitalized patients with COVID-19. In appropriately selected patients, TTE can be an invaluable tool for guiding COVID-19 clinical management.

Importance of surgical expertise in septal myectomy for obstructive hypertrophic cardiomyopathy.

OBJECTIVE: In 2011, a multidisciplinary hypertrophic cardiomyopathy (HCM) program with a dedicated myectomy surgeon was implemented at our institution. We hypothesized that a dedicated approach allows better identification and management of mitral regurgitation (MR) during septal myectomy (SM) for obstructive HCM with significant mitral regurgitation. METHODS: Between 2006 and 2018, 181 patients had SM at our institution. This study consists of 53 patients with preoperative moderate or greater MR associated with systolic anterior motion who underwent isolated SM with or without mitral intervention. Patients were divided into those who underwent SM by a dedicated myectomy surgeon (group D, n = 31) or by a non-dedicated surgeon (group ND, n = 22). Primary outcome of interest was rate of mitral valve replacement (MVR) at SM. Secondary outcomes include in-hospital mortality, need for permanent pacemaker, mitral valve reoperation, and residual MR and left ventricular outflow tract gradient on postoperative echocardiography. RESULTS: 12 patients (55%) had a concomitant MVR during septal myectomy in group ND compared to 2 patients (6%) in group D (p < 0.01). Among patients who did not undergo MVR, patients in group D less commonly had residual MR than patients in ND after SM (p < 0.01). Group D had 100% survival with NYHA class I in 94% patients at follow-up visit (p = 0.01). Reoperation for MVR was required in four patients in group ND vs. none in group D (p < 0.01). CONCLUSIONS: A dedicated surgeon is able to spare the mitral valve in patients undergoing SM. This study emphasizes the importance of surgical expertise in this cohort.

Impact of Septal Myectomy Volume on Mitral-Valve Replacement Rate in Hypertrophic Cardiomyopathy Patients.

OBJECTIVE: Mitral regurgitation (MR) induced by systolic anterior motion in patients with hypertrophic cardiomyopathy (HCM) can frequently be abolished with a proficient septal myectomy (SM) without the need for mitral-valve replacement (MVR). ACC guidelines stress the importance of volume in improving outcomes after SM, but there is a lack of data measuring the impact of volume on the need for MVR during SM. This study was designed to assess the impact of institutional volume on MVR rates using national outcomes data. METHODS: The Nationwide Inpatient Sample was queried from 1998 to 2011 and a total of 6,207 patients had a diagnosis of HCM and a procedure code for SM. Outcomes were compared between patients who underwent SM (group I) and SM and MVR (group II). Furthermore, patients were stratified into 3 groups based on the number of SMs at the performing institution: low experience (1-24 cumulative SMs), medium experience (25-49 SMs), and high experience (>50 SMs). These patients underwent multivariable analysis to determine the impact of institutional volume on MVR rate. RESULTS: The total MVR rate was 26%. Perioperative outcomes were worse, i.e., there were higher rates of mortality, kidney injury, and urinary complications, in group II than in group I. Only 37.6% of patients were operated on at institutions meeting the guideline criteria of >50 cumulative SMs. When compared to patients in the high-experience group, patients in the low- (OR 2.7, 95% CI 2.3-3.2, p < 0.05) and medium-experience (OR 3.0, 95% CI 2.5-3.6, p < 0.05) groups were more likely to undergo MVR. CONCLUSION: Compared to reports from SM reference centers, national data suggest that MVR rates are quite high at SM. Patients undergoing SM at centers that do not meet the guideline standard have >2.5× the odds of undergoing MVR compared to those operated on at guideline-endorsed centers.

Repeat Revascularization for Severe Recurrent Coronary Artery Disease in a Young Woman With Takayasu Arteritis.

A young woman with Takayasu arteritis presented with an acute coronary syndrome with ostial left main coronary artery stenosis. She underwent urgent coronary artery bypass surgery but developed recurrent symptoms 6 months later owing to graft failure. She was treated with percutaneous coronary intervention with resolution of her symptoms. (Level of Difficulty: Beginner.).

Septal myectomy for hypertrophic cardiomyopathy: important surgical knowledge and technical tips in the era of increasing alcohol septal ablation.

Hypertrophic cardiomyopathy (HCM) is the most commonly inherited cardiac disease-recent studies suggest a prevalence as high as 1 in 200. For symptomatic patients with obstructive HCM who are refractory to medical therapy, septal reduction is indicated. Septal myectomy (SM) is considered the gold standard septal reduction technique. However, due to a shortage of surgeons who are experienced in this technique, alcohol septal ablation (ASA) has overtaken SM as the most commonly performed procedure for obstructive HCM. In this review, we summarize the existing literature comparing SM with ASA and describe recent innovations in operative technique, including a detailed description of the approach used at our institution.