Mitral regurgitation in hypertrophic obstructive cardiomyopathy: The role of the edge-to-edge technique.

Mitral regurgitation in hypertrophic obstructive cardiomyopathy (HOCM) is mainly due to systolic anterior motion (SAM) and may be abolished in most of the patients by extended myectomy alone. However, a minority of HOCM patients may present mitral regurgitation due to organic mitral valve (MV) anomalies (such as MV leaflet prolapse, chordal rupture, leaflet cleft, and fibrosis) which need to be addressed. In addition, when the thickness of the interventricular septum is not particularly pronounced, shallow myectomy may not be enough to eliminate SAM and additional procedures have been proposed, including MV replacement, anterior leaflet plication/extension, reorientation of papillary muscles, secondary chordae cutting, and edge-to-edge technique. MV repair in the context of hypertrophic cardiomyopathy is certainly more challenging due to the suboptimal exposure of the MV related to the presence of a hypertrophic left ventricle and a not particularly dilated left atrium. The simplest, least time-consuming repair technique should, therefore, be chosen. In this setting, the edge-to-edge technique has the great advantage of being an easy, quick, and reproducible procedure. The disease process of HOCM is not confined to the myocardium, but also involves the MV apparatus, which plays a critical role in dynamic left ventricular outflow tract (LVOT) obstruction. A comprehensive approach utilizing multimodality imaging, particularly echocardiography and cardiac magnetic resonance, has identified multiple abnormalities of the MV complex that have enhanced our understanding of the mechanisms of SAM and LVOT obstruction in HOCM.

Acute and chronic effects of endocardial radiofrequency ablation of septal hypertrophy in HOCM.

INTRODUCTION: Endocardial radiofrequency ablation of septal hypertrophy (ERASH) is an alternative to alcohol septal ablation (ASA) or surgical myectomy for hypertrophic obstructive cardiomyopathy (HOCM). Several studies have confirmed that septal radiofrequency ablation leads to a significant reduction in the left ventricular outflow tract gradient. OBJECTIVES: We aimed to report the outcomes of 41 patients who underwent ERASH with a focus on severe complications. METHODS: Since 2004, 41 patients with HOCM (age: 58.2 ± 13 years) underwent ERASH at our institution. ERASH was performed, since ASA was ineffective (26 patients) or not possible (15 patients). RESULTS: The left ventricular outflow tract and the right ventricular septum were ablated in 26 and 15 patients, respectively. ERASH resulted in a significant reduction in acute gradient during the session and the results persisted during the 6-month follow-up (67% gradient reduction at rest and 73% after provocation, p = .0002). Pacemaker dependency after ERASH was 29% and pericardial tamponade occurred in two patients. In four patients, ERASH induced a paradoxical increase in obstruction (PIO), beginning suddenly at 30 min after the procedure and leading to lethal shock in one patient. PIO was not observed after ERASH from the right ventricular aspect. CONCLUSION: Morbidity and mortality after ERASH were higher than those after ASA. PIO, a life-threatening complication, was observed in 9% of the patients. Our data indicate that ERASH might be considered in patients who are not candidates for surgical myectomy or ASA.

Echocardiographic and clinical outcomes of patients undergoing septal myectomy plus anterior mitral leaflet extension for hypertrophic cardiomyopathy.

Septal myectomy is indicated in patients with obstructive hypertrophic cardiomyopathy (HCM) and intractable symptoms. Concomitant mitral valve (MV) surgery is performed for abnormalities contributing to systolic anterior motion (SAM), or for SAM-mediated mitral regurgitation (MR) with or without left ventricular outflow tract (LVOT) obstruction. One MV repair technique is anterior mitral leaflet extension (AMLE) utilizing bovine pericardium, stiffening the leaflet and enhancing coaptation posteriorly. Fifteen HCM patients who underwent combined myectomy-AMLE for LVOT obstruction or moderate-to-severe MR between 2009 and 2020 were analyzed using detailed echocardiography. The mean age was 56.6 years and 67% were female. The average peak systolic LVOT gradient and MR grade measured 73.4 mmHg and 2.3, respectively. Indications for myectomy-AMLE were LVOT obstruction and moderate-to-severe MR in 67%, MR only in 20%, and LVOT obstruction only in 13%. There was no mortality observed, and median follow-up was 1.2 years. Two patients had follow-up grade 1 mitral SAM, one of whom also had mild LVOT obstruction. No recurrent MR was observed in 93%, and mild MR in 7%. Compared with preoperative measures, there was a decrease in follow-up LV ejection fraction (68.2 vs 56.3%, p = 0.02) and maximal septal wall thickness (25.5 vs 21.3 mm, p < 0.001), and an increase in the end-diastolic diameter (21.9 vs 24.8 mm/m2, p = 0.04). There was no change in global longitudinal strain (-12.1 vs -11.6%, p = 0.73) and peak LV twist (7.4 vs 7.3°, p = 0.97). In conclusion, myectomy-AMLE is a viable treatment option for carefully selected symptomatic HCM patients with LVOT obstruction or moderate-to-severe MR.

A systematic review and pooled analysis of septal myectomy and edge-to-edge mitral valve repair in obstructive hypertrophic cardiomyopathy.

Left ventricular outflow tract (LVOT) obstruction and systolic anterior motion (SAM) of the mitral valve (MV) occurs in 70% of hypertrophic cardiomyopathy (HCM) patients. In individuals undergoing septal myectomy, concomitant MV surgery is considered for SAM with residual LVOT obstruction or mitral regurgitation (MR); however, the optimal approach remains debated. A literature search was performed in Pubmed, EMBASE, Ovid, and the Cochrane library of published articles through June 2021 reporting on combined septal myectomy and edge-to-edge MV repair for obstructive HCM. Continuous variables were weighted and compared using a student's t-test, and categorical variables using a chi-square test with Yates correction. Six studies with 158 total patients were included. The mean follow-up was 2.8 ± 2.7 years. Compared with pre-operative values, there were significant reductions in the LV ejection fraction (69 ± 10 vs 59 ± 8%), peak LVOT gradient (82 ± 34 vs 16 ± 13 mmHg), prevalence of moderate or greater MR (84 vs 5 %), and presence of SAM (96% vs 0) (p < 0.001 for all). There was no change in LV internal diastolic diameter (4.2 ± 1.3 vs 4.4 ± 1.5 cm, p = 0.32). There were 2 (1%) operative mortalities. At follow-up, the survival rate was 97%, there were 3 (2%) re-operative MV replacements, 4 (3%) patients remained in New York Heart Association functional class III/IV, and 8 (6%) required permanent pacemaker implantation. In conclusion, combined septal myectomy and edge-to-edge MV repair is a safe and effective treatment strategy in carefully selected patients requiring surgical HCM management.

Early and midterm results of extended septal myectomy: Indian experience.

BACKGROUND AND OBJECTIVES: Hypertrophic obstructive cardiomyopathy (HOCM) is a genetic disorder, which is a cause of significant morbidity and sudden cardiac death. Extended septal myectomy (ESM) is the therapeutic gold standard to treat left ventricular outflow tract obstruction (LVOTO) in HOCM resulting in long-term symptomatic relief. The aim of the study was to assess the impact of ESM on midterm symptom relief, LVOTO, and survival in patients suffering from HOCM in the Indian population. METHODS: We retrospectively analyzed clinical data of 36 consecutive symptomatic patients with HOCM having symptoms refractory to medical treatment and LVOTO with resting gradient ≥ 50 mmHg and who underwent ESM at our institution from 2010 to 2019. Preoperative and postoperative transthoracic echocardiography was performed to assess left ventricular outflow tract (LVOT) gradient, septal thickness, and assessment of valvar and cardiac function. RESULTS: ESM was performed successfully in all 36 patients. The mean preoperative LVOT gradient was 113.06 ± 36.70 mmHg and decreased to 15.17 ± 7.30 mmHg (p < .0001) in the initial postoperative period. There were two in-hospital deaths (5.6%). There was no further mortality in the subsequent follow-up. The mean septal thickness was 23.89 ± 5.77 mm preoperatively and 13.17 ± 3.48 mm (p < .0001) postoperatively. During a mean follow-up of 2 years, the NYHA functional class improved from 3.50 ± 0.70 (III-IV) to 1.50 ± 0.70 (I) (p < .0001). CONCLUSIONS: ESM results in immediate abolition of mechanical obstruction to LVOT with normalization of left ventricular pressure and eliminates symptoms associated with HOCM.

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.

Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy: A 16-Year Australian Single Centre Experience.

BACKGROUND: Alcohol septal ablation (ASA), is a well-established treatment for symptomatic hypertrophic obstructive cardiomyopathy (HOCM). We report the acute, short and long-term clinical and echocardiographic outcomes of our experience in a single Australian centre over 16 years. METHODS: We retrospectively analysed consecutive patients presenting to our centre for ASA between March 2000 and July 2016. Local databases were interrogated along with direct patient or physician contact occurred where required. RESULTS: Alcohol septal ablation was performed in 80 patients with symptomatic, medication refractory HOCM (mean age 61±15 years; range 22-84 years; 50% male). All patients had transthoracic echocardiography prior to the procedure, within 48hours of the procedure, 6 weeks, 6 months, 1 year and yearly thereafter to a median follow-up of 80±40months. At baseline, mean resting and provoked LVOT gradients were 80±49mmHg and 97±40mmHg respectively. Compared with baseline, ASA led to a reduction in resting LVOT gradients at all time points, particularly at 2 days-52±41mmHg, p<0.001; 12 months-29±34mmHg, p<0.001; and last follow-up 12±21mmHg, p<0.001. Provoked LVOT gradients were also reduced at 2 days-64±44mmHg and last follow-up of 19±29mmHg, p<0.001. Compared to baseline (19.8±4.2mm), ASA was associated with a reduction in interventricular septal (IVS) thickness at all time intervals with last echocardiographic follow-up at 80 months being 16.0±4.9mm, (

Release kinetics of high-sensitivity cardiac troponins I and T and troponin T upstream open reading frame peptide (TnTuORF) in clinically induced acute myocardial infarction.

CONTEXT: Troponin T upstream open reading frame peptide (TnTuORF) may be useful as a novel biomarker in acute cardiac syndromes. OBJECTIVE: The study examined the early release kinetics of TnTuORF. MATERIALS AND METHODS: We analyzed the time course of the release of cardiac troponins I and T and TnTuORF in patients (n = 31) with hypertrophic obstructive cardiomyopathy undergoing transcoronary ablation of septal hypertrophy (TASH). RESULTS: Fifteen minutes after TASH, the levels of both troponins increased significantly (cTnT median: 18 ng/L versus 27 ng/L; cTnI median: 15 ng/L versus 25 ng/L). TnTuORF showed no variation. DISCUSSION: We observed a significantly greater increase in cTnI compared with cTnT. CONCLUSION: Our results demonstrate that troponin assays allow early detection of myocardial injury, whereas TnTuORF levels remain unchanged in this setting.

An acquired Gerbode defect from the left ventricle to the coronary sinus following mitral valve replacement.

We report the management of an acquired Gerbode defect, from the left ventricle to the coronary sinus, following mechanical mitral valve replacement. Following a failed percutaneous closure, surgical patch closure of the defect was performed.

Transapical intramyocardial septal microwave ablation in treatment of hypertrophic obstructive cardiomyopathy: 12-month outcomes of a swine model.

BACKGROUND: To date, the extended Morrow procedure is considered the gold standard treatment for patients with obstructive hypertrophic cardiomyopathy who experience severe symptoms and are unresponsive to medication treatment. We therefore aimed to perform transapical intramyocardial septal microwave ablation to reduce the thickness of the interventricular septum myocardium in a minimally invasive method. METHODS: Fourteen swine were divided to form either a microwave ablation group (n = 7) or a sham group (n = 7). In the microwave ablation group, a transapical microwave antenna was inserted into the septum to ablate each myocardial segment at 40 W for 1 min, while in the sham group, the same operation was performed but without power output. We used echocardiography, electrocardiogram, during the operation. And added computerized tomography, cardiac nuclear magnetic resonance during follow-up. RESULTS: Segment hypokinesis was observed in all swine immediately following ablation. Compared with the sham group, the thickness of ablated segments in the ablation group decreased significantly 1 month post-operation (ablation group, 5.53 ± 1.00 mm vs. 8.03 ± 1.15 mm, respectively, P < 0.01; sham group, 8.40 ± 0.94 mm vs. 8.21 ± 1.09 mm, respectively, P = 0.081), and the outcome was still observed 1 year post-operation (ablation group, 3.36 ± 0.85 mm vs. 8.03 ± 1.15 mm, respectively, P < 0.01). No perforation of the septum was observed during the procedure or follow-up, and no heart failure or sudden cardiac death occurred during postoperative feeding. CONCLUSIONS: Transapical intramyocardial septal microwave ablation can effectively and safely produce a large region of necrosis. This technique can potentially mimic surgical myectomy while avoiding cardiopulmonary bypass and median sternotomy in high-risk hypertrophic obstructive cardiomyopathy patients.

Fever Unveiling a Hidden Cardiac Condition: A Case of Pediatric Hypertrophic Obstructive Cardiomyopathy.

This case report presents the clinical management of a 18-month-old female child who presented with fever, cough, and cold symptoms for eight days. Despite initial treatment with antipyretic syrup, the persistence of symptoms prompted further evaluation, revealing signs of hypertrophic obstructive cardiomyopathy (HOCM) on echocardiography. The patient was subsequently initiated on beta-blocker therapy and supportive care, leading to clinical improvement and eventual discharge. This case underscores the importance of considering cardiac etiologies in pediatric patients presenting with nonspecific symptoms. It highlights the role of timely diagnosis and multidisciplinary management in optimizing outcomes for affected individuals. Further research and awareness efforts are warranted to enhance diagnostic capabilities and refine treatment strategies for pediatric cardiac conditions like HOCM.

Ischemic Myocardial Positron Emission Tomography Perfusion Without Epicardial Coronary Disease in Hypertrophic Obstructive Cardiomyopathy.

The presence of impaired microvascular coronary flow (MCF) identified by positron emission tomography myocardial perfusion imaging (PET-MPI) has been described in hypertrophic obstructive cardiomyopathy (HOCM) patients, contributes to blunted myocardial perfusion during vasodilator stress, and is a strong predictor of poor prognosis. A 45-year-old female with hypertension and obesity presented with angina. Her PET-MPI displayed vasodilator stress-induced global LV ischemia. However, her coronary angiogram revealed no obstructive coronary disease. These contradictory findings triggered a more thorough cardiac MRI with diffuse myocardial fibrosis, indicating high-risk HOCM. She underwent implantable cardioverter-defibrillator (ICD) placement due to non-sustained ventricular tachycardia and syncope. While this patient lacked epicardial coronary disease, her PET-MPI demonstrated global LV ischemia due to decreased MCF, leading to inadequate augmentation of myocardial perfusion during hyperemia. This is a well-described phenomenon responsible for anginal symptoms in HOCM patients. HOCM hearts have abnormally thick coronary arterioles and decreased capillary density, leading to increased oxygen diffusion distances and reduced perfusion. The presence of vasodilator-induced, global ischemia on PET-MPI without epicardial stenosis should raise suspicion for HOCM with impaired MCF, which represents a high-risk population with an almost 10 times greater risk of cardiovascular mortality compared to hypertrophic cardiomyopathy with preserved MCF.

Apical Hypertrophic Cardiomyopathy With a Sub-aortic Membrane: A Case Report.

Hypertrophic obstructive cardiomyopathy (HOCM) and subaortic membrane (SAS) are distinct cardiac conditions, but their coexistence presents complex diagnostic challenges. We report the case of a 52-year-old male with HOCM and a concurrent subaortic membrane, highlighting the intricacies of diagnosis and management. The patient's presentation included symptoms of dyspnea and chest tightness, and diagnostic evaluations revealed a unique combination of dynamic left ventricular outflow tract (LVOT) obstruction from HOCM and fixed obstruction from the subaortic membrane. This case emphasizes the importance of a comprehensive diagnostic workup to guide appropriate treatment decisions when managing multiple cardiac abnormalities.

An Interesting Case of Wolf-Parkinson-White Syndrome in a Young Patient With Sensorineural Deafness.

Wolff-Parkinson-White (WPW) syndrome is a condition associated with tachycardia due to accessory pathways in the heart, and it is one of the most common causes of tachycardia in infants and children. WPW may also be associated with mitochondrial encephalomyopathy, lactic acidosis, stroke-like episodes (MELAS syndrome) or LEOPARD syndrome (LS). We report a case of pre-excitation WPW syndrome in a 17-year-old man who was brought to the hospital by ambulance following the collapse. WPW syndrome type A was diagnosed from precordial leads. Electrocardiography (ECG) revealed a short PR interval, delta waves, and positive waves with dominant R in all pericardial leads. Blood test results showed an isolated elevated ALT level. Subsequent echocardiography was unremarkable, with an ejection fraction of 55%, apart from septal and inferior wall dyssynchrony. With regard to the past medical history, he had sensorineural deafness (SND) since childhood and had a family history of SND. Consequently, the patient was transferred to the cardiac electrophysiology department at another hospital after consultation and underwent ablation. A successful post-ablation electrocardiogram revealed the resolution of the WPW syndrome signs and post-ablation features, such as peak T waves.

Anesthetic Management of Intra-aortic Balloon Pump-Induced Systolic Anterior Motion of the Mitral Valve During Coronary Artery Bypass Grafting.

The intra-aortic balloon pump (IABP) is a mechanical device that increases myocardial oxygen perfusion and indirectly increases cardiac output through afterload reduction. Since its inception, the IABP has been a mainstay of cardiac support devices, utilized as a temporizing measure in patients with or prone to developing cardiogenic shock that are awaiting definitive treatment. Systolic anterior motion (SAM) of the mitral valve is a well-described phenomenon that can precipitate hemodynamic collapse by obstructing the left ventricular outflow tract in a subset of patients with cardiac pathology, most notably hypertrophic obstructive cardiomyopathy (HOCM). This report describes the case and anesthetic management of a patient who had an IABP placed for support and later developed SAM and hemodynamic compromise after induction of general anesthesia during a coronary artery bypass surgery.

A repeat alcohol septal ablation procedure for hypertrophic obstructive cardiomyopathy where the first septal branch arose from the intermediate (ramus) artery.

Septal reduction therapy (via alcohol septal ablation or surgical myomectomy) is indicated in patients with hypertrophic obstructive cardiomyopathy (HOCM) who have NYHA class III/IV symptoms despite maximal medical therapy. In 90% of patients with HOCM the target septal artery arises from the LAD or diagonal artery. In the remaining 10% of cases it may arise from the ramus, proximal circumflex, or posterolateral or posterior descending branches of the RCA. We present a case where alcohol septal ablation was initially performed on the first septal branch arising from the left anterior descending artery. Left ventricular outflow tract (LVOT) obstruction with symptoms recurred. Upon repeat angiography, a large septal branch in fact arose from the proximal intermediate (ramus) artery. Alcohol ablation of this branch achieved a sustained response. This case highlights that correctly identifying the most suitable septal perforating artery, in addition to myocardial contrast echocardiography, may improve response rates and overall outcomes for patients with hypertrophic obstructive cardiomyopathy.

Safety and efficacy of mavacamten for treatment of hypertrophic cardiomyopathy: a systematic review and meta-analysis of randomized clinical trials.

BACKGROUND: Mavacamten, an allosteric myosin inhibitor, is considered to be a promising drug for the treatment of hypertrophic cardiomyopathy (HCM). This meta-analysis aimed to explore the safety and efficacy of mavacamten in HCM patients. MAIN BODY: A total number of 539 patients were enrolled in four randomized clinical trials. The mean age of patients was 57.9 years and was followed for 29.3 weeks. Pooled analysis showed a significant improvement in clinical response (Log OR = 0.65; p = 0.01) and the number of patients with a reduction of ≥ 1 NYHA function class (Log OR = 0.64, p = 0.00). It was found that mavacamten did not significantly affect the Kansas City Cardiomyopathy Questionnaire (KCCQ) (SMD = 0.43, p = 0.08), peak oxygen uptake (PVO2) (SMD = 0.24, p = 0.42), and ejection fraction (EF) (SMD = - 0.65, p = 0.13) as compared with placebo. However, KCCQ (SMD = 0.65, 95% CI 0.44-0.87) and PVO2 (SMD = 0.49, 95% CI 0.24-0.74) improvements were statically significant in the hypertrophic obstructive cardiomyopathy subgroup (HOCM), and a significant decrease in EF (SMD = -- 1.14, 95% CI - 1.86 to - 0.42) was found in the HOCM subgroup. No significant difference was observed in the incidence rate of serious adverse events between mavacamten and placebo group (Log OR = - 0.23, p = 0.56). CONCLUSIONS: Mavacamten proved to be effective and well-tolerated for the treatment of HCM. Mavacamten improved the signs and symptoms of HOCM and decreased EF in these patients without serious adverse events in the clinical trials.

The triglyceride-glucose index as a potential protective factor for hypertrophic obstructive cardiomyopathy without diabetes: evidence from a two-center study.

OBJECTIVE: This study aimed to investigate the relationship between the TyG (Triglyceride-glucose index) and the prognosis of patients with HOCM (hypertrophic obstructive cardiomyopathy) without diabetes. RESEARCH DESIGN AND METHODS: A total of 713 eligible patients with HOCM were enrolled in this study and divided into two groups based on treatment: an invasive treatment group (n = 461) and a non-invasive treatment group (n = 252). The patients in both two groups were then divided into three groups based on their TyG index levels. The primary endpoints of this study were Cardiogenic death during long-term follow-up. Kaplan-Meier analysis was used to study the cumulative survival of different groups. Restricted cubic spline was used to model nonlinear relationships between the TyG index and primary endpoints. Myocardial perfusion imaging/Myocardial metabolic imaging examinations were performed to assess glucose metabolism in the ventricular septum of the HOCM patients. RESULTS: The follow-up time of this study was 41.47 ± 17.63 months. The results showed that patients with higher TyG index levels had better clinical outcomes (HR, 0.215; 95% CI 0.051,0.902; P = 0.036, invasive treatment group; HR, 0.179; 95% CI 0.063,0.508; P = 0.001, non-invasive treatment group). Further analysis showed that glucose metabolism in the ventricular septum was enhanced in HOCM patients. CONCLUSIONS: The findings of this study suggest that the TyG index may serve as a potential protective factor for patients with HOCM without diabetes. The enhanced glucose metabolism in the ventricular septum of HOCM patients may provide a potential explanation for the relationship between the TyG index and HOCM prognosis.