Ventricular Outflow Tract Obstruction Research Articles

Infective endocarditis in an adult with undiagnosed tetralogy of Fallot: a case report of a rare presentation.

Unrepaired tetralogy of Fallot (TOF) is uncommonly diagnosed in adulthood and only 3% of patients survive to reach the age of 40 without surgical repair. If unrepaired, these patients are at risk for infective endocarditis (IE). In this report, we present a case of a middle-aged, previously healthy female whose only complaint was unexplained fever. Echocardiography led to the discovery of undiagnosed TOF complicated with IE with a vegetation on the right ventricular (RV) side of the ventricular septal defect (VSD) which was appropriately managed with antibiotics. In rare cases of acyanotic TOF where there is a lesser degree of right ventricular outflow tract obstruction (RVOTO), patients may survive into adulthood and can be asymptomatic till becoming initially presented with complications such as infective endocarditis.

Abstract 4123391: CardioMEMS and Mavacamten: A Synergistic Approach in Managing Hypertrophic Obstructive Cardiomyopathy with HFpEF Phenotype

Introduction: Mavacamten is a cardiac myosin inhibitor that has been approved for obstructive hypertrophic cardiomyopathy (oHCM). The CardioMEMS PA (pulmonary artery) sensor allows remote pulmonary artery diastolic (PAD) pressure monitoring to adjust diuresis in heart failure with preserved ejection fraction (HFpEF). We present the case of a patient with oHCM and HFpEF where data extrapolated from CardioMEMS provided valuable insight to the hemodynamic impact of cardiac myosin inhibitors. Case: A 66-year-old female with hypertension, obesity and oHCM presented with worsening dyspnea and was evaluated for septal myectomy. However, surgery was deferred because of decompensated HFpEF, as evidenced by significant leg edema on exam, and severely elevated left and right-side filling pressure, with restrictive physiology on right heart catheterization. A CardioMEMS PA sensor was implanted to guide decongestion, however, escalation of diuresis was limited due to severe left ventricular outflow tract (LVOT) obstruction. PAD remained elevated at 20-30 mmHg. Due to the refractory LVOT obstruction and despite the use of maximally tolerated beta blockers, Mavacamten was initiated and escalated according to protocol. LVOT obstruction resolved on follow up echocardiogram. Without any adjustment in her diuretic regimen, her PAD decreased to 15-20 mmHg. On follow-up visit, the patient reported improvement in dyspnea and reduction in lower extremity edema. Discussion: Managing oHCM is challenging, particularly when complicated by HFpEF. Mavacamten has shown promise in reducing LVOT gradients and improving symptoms in oHCM. However, managing fluid status in these patients can be difficult due to the risk of exacerbating LVOT obstruction while optimizing filling pressures. Our case provides direct evidence that treating LVOT obstruction with a cardiac myosin inhibitor leads to improvement in decompensated heart failure, as evidenced by the reduction in PAD. Conclusion: Addressing LVOT obstruction is key to decongesting and managing heart failure in oHCM patients. In our case, the use of CardioMEMS PA sensor system allowed a novel perspective of assessing hemodynamic impact of cardiac myosin inhibitors.

Abstract 4135212: An Overlap Between Takotsubo Cardiomyopathy and Hypertrophic Obstructive Cardiomyopathy Causing Dynamic Left Ventricular Outflow Tract Obstruction: A Unique Case Report

Background: Takotsubo cardiomyopathy (TC) can cause dynamic left ventricular outflow tract (LVOT) obstruction leading to cardiogenic shock. Due to differential wall-motion abnormalities, flow acceleration in the LVOT can lead to systolic anterior motion (SAM) of the mitral valve which worsens LVOT obstruction and leads to hemodynamic compromise. We present a case of overlap between TC and hypertrophic obstructive cardiomyopathy (HOCM) with worsening LVOT obstruction leading to cardiogenic shock. Case: A 76-year-old female presented with typical chest pain, nausea, and worsening shortness of breath. On examination, she was hypotensive and cold to touch. EKG showed T-wave inversions in lateral leads with elevated cardiac troponins. Coronary angiogram showed non-obstructive coronary artery disease, and right heart catheterization revealed elevated filling pressures. Transthoracic echocardiogram (TTE) showed septal hypertrophy and SAM of the mitral valve causing dynamic LVOT obstruction (Figure 1) and ejection fraction (EF) of 20%. TTE with contrast showed apical ballooning consistent with TC (Figure 2). Decision Making: Initially with diuresis, she became hypotensive so it was stopped and she received controlled intravenous fluids along with phenylephrine to reduce LVOT obstruction. Her blood pressure improved and she was started on low-dose metoprolol succinate along with ivabradine to reduce heart rate. She tolerated this therapy and hemodynamics stabilized. Conclusion: Cardiogenic shock can be a severe complication of TC. Early detection of LVOT obstruction in cardiogenic shock is important as traditional management strategies of increased inotropy and reduction of afterload can be fatal in these cases. The treatment strategy focuses on reducing the LVOT gradient and includes fluid administration to increase preload, beta-blockers to increase diastolic filling time, and vasopressors to raise afterload.

Abstract 4138007: Mechanisms of Mitral Regurgitation in Fabry Disease

Introduction: Fabry disease, caused by mutations in the gene encoding alpha-galactosidase A, results in the accumulation of globotriaosylceramide (Gb3), leading to systemic complications including cardiac involvement such as mitral regurgitation (MR). The aim of this study is to investigate the association between MR severity and mitral leaflet morphology in Fabry disease patients. A cohort of 38 symptomatic Fabry disease patients with moderate or significant MR was followed up. Mitral leaflet morphology was categorized as normal, fibrodegenerative changes, or leaflet thickening. MR severity varied, with the primary cause being leaflet restriction. Additionally, left ventricular outflow tract obstruction (LVOTO) and annular dilatation were observed. The study suggests that MR in Fabry disease is primarily due to leaflet restriction, either through degenerative changes or leaflet thickening. This study investigates the association between MR severity and mitral leaflet morphology in Fabry disease patients. Methods: A cohort of 38 symptomatic Fabry disease patients with moderate or significant MR was followed up. Echocardiographic assessments were conducted to determine MR severity and categorize mitral leaflet morphology. Statistical analyses were performed to evaluate associations between MR severity and leaflet morphology. Echocardiographic assessments of the mitral valve were conducted using a Vivid E95 Cardiac Ultrasound and meticulously analyzed using the EchoPAC TM and TOMTEC Imaging Systems. A crucial aspect of the examination involved measuring all components of the mitral valve and determining the requisite angles to evaluate each mechanism thoroughly. Results: Most patients exhibited leaflet restriction as the primary cause of MR, with varying degrees of severity. Mitral leaflet morphology was categorized as normal in 15,8%, fibrodegenerative changes were in 31,5% and leaflet thickening in 52,7%. In addition, outflow tract obstruction (LVOTO) was observed in 15,7% but without systolic anterior motion (SAM) and annular dilatation (dilatation of anteroposterior annulus more than 35 mm in systole) was present in 66%. Conclusion: The study suggests that MR in Fabry disease is primarily attributed to leaflet restriction, either due to degenerative changes or leaflet thickening. An additional, albeit not unexpected, finding not always considered is the presence of anteroposterior annular dilatation in some cases.

Abstract 4128606: Detailed Measurements of Surgical Mitral Valves: Implications for Transcatheter Mitral Valve-in-Valve Interventions

Background: With the increasing prevalence of transcatheter mitral valve-in-valve interventions (V-in-V), a detailed understanding of the surgical valves (SV) is of paramount importance. Left ventricular outflow tract obstruction (LVOTO) is a feared complication and is typically caused by the anterior displacement of the LVOT-facing surgical leaflet, which, along with the surgical post at that level, forms a fixed obstruction. Traditionally, the risk is estimated using computed tomography software by simulating a valve that extends to the surgical post height of the implanted SV. However, this does not account for the actual leaflet length and post width at the level of the leaflet tip, which could differ significantly from the surgical post height but accurately estimate LVOTO risk. Methods: We conducted detailed measurements of three different sizes of two commonly used surgical mitral valves: the Biocor EPIC ( Abbott ) in sizes 27 mm, 31 mm, and 33 mm, and the Mosaic ( Medtronic ) in sizes 25 mm, 31 mm, and 33 mm. Using a digital caliper and height gauge, we measured several key parameters for each valve, including leaflet height, post height, leaflet width, post width at the level of the leaflet tip, maximal post width, and valve inner diameter. Results: The results, presented in Table 1, show significant differences in leaflet height and post widths across manufacturers and sizes. Leaflet height was consistently shorter than post height in both Abbott and Medtronic valves, with this discrepancy more pronounced in larger valves and Medtronic valves. The post width at the leaflet tip also varied considerably. Conclusions: Given the substantial differences between leaflet and post heights—with the leaflet typically much shorter—an accurate assessment of LVOTO risk should account for both the leaflet height and the width of the post at that level to avoid overestimating the risk of LVOTO.

Abstract 4147610: Efficacy and Safety of Selective Cardiac Myosin Inhibitors in Symptomatic Hypertrophic Obstructive Cardiomyopathy: A Meta-Analysis of Randomized Controlled Trials

Background: Hypertrophic Obstructive Cardiomyopathy (HOCM) is an autosomal dominant inherited condition with limited management options, primarily focusing on symptom improvement through beta blockers. A novel selective cardiac myosin inhibitor, Mavacamten has been shown to improve exercise tolerance and NYHA functional class as compared to placebo in multiple randomized controlled trials (RCTs). A recent RCT from 2024 studied another oral cardiac myosin inhibitor, Aficamten which potentially decreases left ventricular outflow tract obstruction (LVOTO) in symptomatic HOCM. One limitation of all these RCTs, for obvious reasons, is the small sample size, which poses a challenge in its actual clinical significance. Aims: To analyze the efficacy and safety of novel selective cardiac myosin inhibitors in symptomatic HOCM patients Methods: We included 4 RCTs, comparing the efficacy and safety of selective cardiac myosin inhibitors and placebo groups. These studies were selected through a detailed search of the MEDLINE, COCHRANE, and PUBMED databases. We compared various common primary and secondary endpoints between both the groups: changes in exercise tolerance, NYHA functional class, and Kansas City Cardiomyopathy Questionnaire-Clinical Summary Score (KCCQ-CSS). The results were reported as Odds Ratios (OR) with 95% confidence intervals (CI), using a random effects model. Results: The outcomes from 704 HOCM patients, which consisted of 361 patients who received a myosin inhibitor and 343 who received a placebo were analyzed. The primary endpoint in all the studies was improvement in exercise tolerance [measured as 1.5 mL/kg per min or greater increase in peak oxygen consumption (pVO2)], which was not statistically significant in our study (OR: 1.75, 95% CI: 0.89-3.43, p:0.1). There was a statistically significant improvement in ≥1 NYHA functional Class (OR: 3.9, 95% CI:2.49-6.12 p<0.05). There was no significant change seen in KCCQ-CSS (OR: 1.26, 95% CI: 0.75-2.12, p:0.3) and1 or more Serious Adverse Events (OR: 0.75, 95% CI: 0.42-1.32, p:0.3). (Figures A-D) Conclusion: Novel cardiac myosin inhibitors have shown statistically significant results in improving NYHA functional class, but not much difference in objective criteria like pVO2 with no significant adverse events. While these results appear promising and 2024 ACC/AHA guidelines have Class 1 Recommendation regarding their use for symptomatic HOCM, further analysis from a large population is needed.

Abstract 4138268: The Use of Mavacamten for Management of Post TAVR Obstruction: A Novel Approach to Treatment

Background: Treatment of left ventricular outflow tract (LVOT) obstruction involves a combination of negative inotropic agents. However, these therapies have limitations which may result in insufficient control of symptoms, leading to more invasive options such as surgical septal myectomy or septal alcohol ablation. Mavacamten, a cardiac myosin inhibitor, is currently approved for the treatment of patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM). We present a case of a patient treated with mavacamten in addition to β-blockers (BB) for management of post-TAVR LVOT obstruction. Case: A 76 year old female with a past medical history of hypertension, severe aortic stenosis, and coronary artery disease underwent a Medtronic Evolut TAVR in March 2022. Her TTE post TAVR showed LVOT peak gradient greater than 100 mm Hg, LVEF 75% and severe eccentric mitral regurgitation secondary to systolic anterior motion (SAM) of the mitral valve (MV). After multidisciplinary discussion, the patient was discharged on maximally tolerated BB therapy. Follow up TTE showed persistent obstruction and gradients, so diltiazem was added to her regimen. Her subsequent TTE showed a peak LVOT > 100 mmHg at rest, and severe MR. Given persistent findings, she was started on mavacamten, continued on metoprolol, and tapered off of diltiazem. Her TTE two months after initiation of mavacamten revealed resolution of LVOT gradients, reduction of MR to mild and normal LV and TAVR function. She tolerated the therapy well and endorsed ongoing symptomatic improvement on subsequent follow up. Discussion: With the increasing use of TAVR therapy, there has been a corresponding rise in cases of post-TAVR obstruction that must be managed. As demonstrated by this case, management with BB therapy alone may be suboptimal. Although mavacamten is currently approved in patients with HCM, the obstruction in post-TAVR patients is functionally similar. Thus, this medication was trialed as a supplemental treatment in this patient and yielded positive results. This case highlights the potential benefit of extending use of mavacamten alongside β-blocker therapy for this patient population and suggests the need for future studies.

Abstract 4132223: Mavacamten in adolescent patients with symptomatic obstructive hypertrophic cardiomyopathy: design of the Phase 3 SCOUT-HCM trial

Background: While most current treatments can improve symptoms in patients with obstructive hypertrophic cardiomyopathy (HCM), they may be poorly tolerated and do not target the underlying pathophysiology. Mavacamten is the first and only cardiac myosin inhibitor approved for the treatment of adults with symptomatic New York Heart Association (NYHA) class II-III obstructive HCM but has not been evaluated in a pediatric age group. SCOUT-HCM (Study of MavaCamten in AdOlescents with Symptomatic ObstrUcTive HCM; NCT06253221) will evaluate the efficacy, safety, and pharmacokinetics of mavacamten in adolescents with symptomatic obstructive HCM. Methods: SCOUT-HCM is a randomized, double-blind, placebo-controlled, international phase 3 clinical trial that will enroll 40 adolescents (age 12 to <18 years) with obstructive HCM ( Figure ). Patients will receive mavacamten or placebo during the first 28 weeks, followed by a 28-week double-blind active treatment period. Inclusion criteria include a diagnosis of HCM with presence of symptoms and left ventricular outflow tract (LVOT) obstruction. Patients with HCM phenocopies, LVEF <50% at rest in the past 6 months, planned escalation in HCM therapy or upcoming intervention (eg, major cardiac surgery) will be excluded. The primary endpoint is change in Valsalva LVOT gradient from baseline to week 28. Key secondary endpoints include other echocardiographic parameters, safety, pharmacokinetics, and exercise capacity. Conclusions: SCOUT-HCM is the first randomized controlled trial evaluating a targeted myosin inhibitor in adolescents with symptomatic obstructive HCM. The results will inform the utility of mavacamten in adolescent patients with symptomatic obstructive HCM.

Residual pulmonary stenosis and right ventricular contractility in repaired tetralogy of fallot.

The impact of residual pulmonary stenosis (rPS) or right ventricular (RV) outflow tract obstruction on prognosis after surgical pulmonary valve insertion (SPVI) in repaired tetralogy of Fallot (TOF) patients with pulmonary regurgitation (PR) remains controversial. rPS assessment is partially dependent on RV contractility. We investigated the impact of rPS according to RV ejection fraction (RVEF). In this multicentre, retrospective study, 117 repaired TOF patients who underwent SPVI for more than moderate PR between 2003-2021 were examined. Regarding rPS, the threshold for PR with rPS (PSR) and PR was 25 mmHg. For RVEF, the threshold for preserved RVEF (pEF) and reduced RVEF (rEF) was 40%. The patients were divided into four groups: patients with PR and pEF (PR-pEF) (n = 48), those with PR and rEF (PR-rEF) (n = 44), those with PSR and pEF (PSR-pEF) (n = 16), and those with PSR and rEF (PSR-rEF) (n = 9). Clinical parameters, postoperative adverse event rates, and their associations were studied. The 5-year freedom from adverse cardiovascular events was the highest in the PSR-pEF and the lowest in the PSR-rEF groups. The PSR-rEF group had the highest RV end-diastolic pressure (RVEDP) (12 ± 2.2 mmHg) (p = 0.006). From multivariable analysis, RVEDP was associated with postoperative adverse events (p = 0.016). RVEDP > 8mmHg was associated with a lower freedom from adverse events. The freedom from adverse events was the lowest in the PSR-rEF group, with the highest RVEDP, suggesting RV systolic and diastolic dysfunction. Reduced RVEF may mask the intrinsic degree of residual stenosis, delay SPVI timing, and increase adverse events.

Diagnosis and management of hypertrophic cardiomyopathy: European vs. American guidelines.

Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease, affecting 1:200 to 1:500 individuals worldwide. Guidelines on the diagnosis and management of HCM have been recently published by the European Society of Cardiology (ESC) and American societies. The ESC guidelines cover a broad range of cardiomyopathies, including HCM, with 119 recommendations, whereas the American guidelines focus exclusively on HCM with 141 specific recommendations. Both guidelines emphasize a comprehensive diagnostic approach, including imaging and genetic testing, but differ in some specific aspects. For example, sudden cardiac death (SCD) risk assessment is a primary point of divergence. The ESC guidelines advocate for the use of a validated Risk-SCD calculator, while the American guidelines rely on specific risk markers for individualized risk evaluation. Management strategies also vary: both guidelines prioritize beta-blockers and calcium channel blockers in patients with resting or provocable left ventricular outflow tract (LVOT) obstruction. If beta-blockers (or verapamil/diltiazem) are ineffective, either disopyramide or the myosin inhibitor mavacamten may be an option with slightly different indications among the two guidelines. Septal reduction therapy is recommended in ESC guidelines for symptomatic patients with significant LVOT gradients, while American guidelines suggest earlier myectomy for certain clinical factors and emphasize shared decision-making. The ESC guidelines recommend sequential atrioventricular pacing and dual-chamber defibrillators for reducing LVOT gradients. The American guidelines focus on genetic testing for risk assessment and suggest periodic cardiac magnetic resonance imaging. This paper provides a detailed comparison of these guidelines, highlighting key differences and areas needing further research and expert debate.

Exercise Training in Patients With Hypertrophic Cardiomyopathy Without Left Ventricular Outflow Tract Obstruction: A Randomized Clinical Trial.

Patients with hypertrophic cardiomyopathy without left ventricular outflow tract obstruction commonly experience reduced exercise capacity. Physical training improves exercise capacity in these patients, but whether the underlying effects of exercise are a result of central hemodynamic or peripheral improvement is unclear. This study assessed whether exercise training reduces left ventricular filling pressure measured during exercise in patients with hypertrophic cardiomyopathy without left ventricular outflow tract obstruction. Between March 2019 and June 2022, patients with hypertrophic cardiomyopathy without left ventricular outflow tract obstruction were randomly assigned (1:1) to a 12-week (3 h/wk) supervised, moderate-intensity exercise training program or continued usual activity. The primary outcome was the change in invasively measured pulmonary capillary wedge pressure during mild exercise (25 W) from baseline to week 12. Pressure tracings were analyzed offline by a blinded investigator. Secondary outcomes included changes in peak oxygen consumption, cardiac index, quality of life, echocardiographic indices of diastolic function, and natriuretic peptides. Of 59 patients randomized (mean age, 58.1±12.2 years; 27% women), 51 (86%) completed all follow-up assessments. At week 12, the change in 25-W pulmonary capillary wedge pressure was -2.8±6.8 mm Hg in the exercise group, compared with +1.2±4.9 mm Hg in the usual-activity group (between-group difference, 4.0 mm Hg [95% CI, 0.7-7.3]; P=0.018). Peak oxygen consumption improved by +1.8±2.0 mL/kg/min in the exercise group versus -0.3±3.1 mL/kg/min in the usual-activity group (P=0.005). Exercise training improved the ventilatory efficiency (VE/VCO2) slope compared with usual activity (between-group difference, 2.0 [95% CI, 0.6-3.5]; P=0.006). Peak cardiac index improved by +0.38±1.38 L/min/m2 in exercise versus -0.85±1.20 L/min/m2 in the usual-activity group (P=0.002). Change in overall Kansas City Cardiomyopathy Questionnaire score was similar between groups. However, the change in physical limitation scores (+8.4±12.0 points in exercise versus +0.7±6.8 points in usual-activity group; P=0.034) and quality-of-life scores (+8.7±18.0 points in exercise versus 0.7±4.0 points in usual-activity group; P=0.01) differed significantly. There were no significant changes in diastolic function assessed by echocardiography or in natriuretic peptides. In patients with hypertrophic cardiomyopathy without left ventricular outflow tract obstruction, a 12-week moderate-intensity exercise training program resulted in reduced left ventricular filling pressures at mild exertion and improved exercise performance. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03537183.

Surgical approach to hypertrophic cardiomyopathy: septoplasty versus transaortic myomectomy

Introduction: Hypertrophic cardiomyopathy (HCM) is a genetic disorder characterized by asymmetric hypertrophy of the myocardium, often resulting in left ventricular outflow tract (LVOT) obstruction. This condition affects approximately 1 in 500 individuals in the general population and is one of the leading causes of sudden death in young people. Surgical treatment is indicated when clinical management fails to relieve symptoms and reduce the risk of adverse events. The two main surgical approaches for obstructive HCM are septoplasty and transaortic myomectomy, aiming to improve blood flow and reduce the intraventricular gradient. However, there is disagreement in the literature regarding which technique offers better long-term outcomes. Objective: The study aims to compare the surgical outcomes of septoplasty and transaortic myomectomy in patients with obstructive hypertrophic cardiomyopathy, evaluating the efficacy of both techniques in reducing symptoms, relieving LVOT obstruction, incidence of postoperative complications, and long-term survival. Methodology: A systematic review was conducted following PRISMA guidelines, with a search in PubMed, Embase, Scopus, Web of Science, and Cochrane Library databases, covering January 2000 to September 2024. Randomized studies, cohorts, and case series that directly compared septoplasty and transaortic myomectomy in patients with obstructive HCM were included. Exclusion criteria included studies that did not directly compare the two techniques, isolated case reports, and narrative reviews. Two independent reviewers conducted study selection, with a third reviewer resolving any discrepancies. Results: Septoplasty showed greater efficacy in reducing symptoms and left ventricular outflow gradient, and was associated with a lower risk of immediate complications such as infection and the need for reoperation. Transaortic myomectomy, while also effective, was associated with a slightly higher risk of surgical complications, particularly in cases of complex septal anatomy. Both procedures showed comparable operative mortality rates, but septoplasty demonstrated better long-term outcomes in terms of survival and preservation of cardiac function. Conclusion: Both septoplasty and transaortic myomectomy are effective techniques for the treatment of obstructive HCM, with septoplasty being preferred due to its lower morbidity profile and better long-term outcomes. However, transaortic myomectomy may be indicated in cases of extensive septal hypertrophy or complex anatomy. Surgical decisions should be individualized, taking into account patient characteristics and the surgical team's experience. Future studies are needed to evaluate the nuances of long-term outcomes in different patient populations.

Accuracy of Three-Dimensional Neo Left Ventricular Outflow Tract Simulations With Transcatheter Mitral Valve Replacement in Different Mitral Phenotypes.

Transcatheter mitral valve replacement (TMVR) is emerging in the context of annular calcification (valve-in-MAC; ViMAC), failing surgical mitral annuloplasty (mitral-valve-in-ring; MViR) and failing mitral bioprosthesis (mitral-valve-in-valve; MViV). A notorious risk of TMVR is neo left ventricular outflow tract (neo-LVOT) obstruction. Three-dimensional computational models (3DCM) are derived from multi-slice computed tomography (MSCT) and aim to predict neo-LVOT area after TMVR. Little is known about the accuracy of these neo-LVOT predictions for various mitral phenotypes. Preprocedural 3DCMs were created for ViMAC, MViR and MViV cases. Throughout the cardiac cycle, neo-LVOT dimensions were semi-automatically calculated on the 3DCMs. We compared the predicted neo-LVOT area on the preprocedural 3DCM with the actual neo-LVOT as measured on the post-procedural MSCT. Across 12 TMVR cases and examining 20%-70% of the cardiac phase, the mean difference between predicted and post-TMVR neo-LVOT area was -23 ± 28 mm2 for MViR, -21 ± 34 mm2 for MViV and -73 ± 61 mm2 for ViMAC. The mean intra-class correlation coefficient for absolute agreement between predicted and post-procedural neo-LVOT area (throughout the whole cardiac cycle) was 0.89 (95% CI 0.82-0.94, p < 0.001) for MViR, 0.81 (95% CI 0.62-0.89, p < 0.001) for MViV, and 0.41 (95% CI 0.12-0.58, p = 0.002) for ViMAC. Three-dimensional computational models accurately predict neo-LVOT dimensions post TMVR in MViR and MViV but not in ViMAC. Further research should incorporate device host interactions and the effect of changing hemodynamics in these simulations to enhance accuracy in all mitral phenotypes.

Konno Rastan Aortoventriculoplasty: The Last Resort for Complex Left Ventricular Outflow Tract Obstruction.

Konno-Rastan aorto-ventriculoplasty is used to enlarge the aortic root in patients with a narrow aortic root that increases the size of the implanted valve. We present the two case reports; one 13-year-old male and another 59-year-old female, who underwent aortic valve replacement and double valve replacement respectively, along with Konno-Rastan aorto-ventriculoplasty. The case reports show that the Konno procedure allows for inserting an appropriately sized prosthesis in case of a small aortic annulus. The Konno technique addresses all levels of Left Ventricular Outflow Tract obstruction, increasing the left ventricular outflow tract more than other techniques. Both of the cases had good long-term follow-up.

Subaortic Pannus Causing Complete Outlet Obstruction After Bioprosthetic Aortic Valve Replacement in a Patient with Left Ventricular Assist Device: A Case Report

Abstract Background Subaortic pannus formation complicates bioprosthetic aortic valve(AV) replacement. We report an extreme case in a continuous-flow left-ventricular-assist-device(LVAD) patient. Case Summary A 49-year-old Caucasian female with dilated cardiomyopathy was bridged-to-transplant with a HeartWare ventricular-assist-device(HVAD). Duration of support was prolonged, 6-years and 7-months, due to allosensitisation requiring desensitisation. Pump thrombosis occurred 2-years and 4-months post-LVAD requiring alteplase thrombolysis. The patient underwent bioprosthetic AV replacement 3-years and 10-months post-LVAD for symptomatic aortic incompetence. Transthoracic echocardiography(TTE) performed 1-year and 2-years post-bioprosthetic AV replacement repeatedly demonstrated an AV closed during all cardiac cycles without incompetence and nil flow through the left-ventricular-outflow-tract(LVOT). Following transplant, analysis of explanted heart revealed a fused AV. A pannus adherent to the underside of the AV had formed across the entire AV outlet, with complete obliteration of LVOT. This subaortic pannus was not visualised on previous TTE. Histologically, the pannus consisted of hypocellular fibrous tissue with chronic inflammatory cells, spindle histiocytes and myofibroblasts scattered throughout the loose fibromyxoid stroma, the latter highlighted on CD68 immunohistochemical stain(IHC). Partial endothelialisation on the pannus surface was highlighted on ERG &amp; CD31 IHC. Neither calcification, nor signs of acute inflammation were noted. In contrast to previous cases, there was no evidence of associated thrombus macroscopically or microscopically. Discussion Prolonged LVAD support may facilitate subaortic pannus following bioprosthetic AV replacement due to AV closure and altered transvalvular flow. Due to the parallel LVAD circulation, subaortic pannus may develop asymptomatically, without haemodynamic compromise, allowing progression to total LVOT obstruction. This requires consideration prior to LVAD explantation in bridge-to-recovery patients.

The Clinical Trajectory of NYHA Functional Class I Patients With Obstructive Hypertrophic Cardiomyopathy.

An improved understanding of the natural history in NYHA functional class I patients with obstructive hypertrophic cardiomyopathy (oHCM) is needed. Using a multicenter registry (SHaRe [Sarcomeric Human Cardiomyopathy Registry]), this study described the natural history in patients with oHCM who were classified as NYHA functional class I at the initial visit compared with patients classified as NYHA functional class II and reported baseline characteristics associated with incident clinical events. Incident events assessed included a composite of NYHA functional class III to IV symptoms, left ventricular ejection fraction<50%, atrial fibrillation, stroke, ventricular arrhythmias, septal reduction therapy, ventricular assist device or transplantation, or death. Factors associated with incident events were determined using Kaplan-Meier, Cox proportional hazards, and restricted cubic spline models. Of 7,964 patients with HCM in SHaRe, 1,239 patients with oHCM met inclusion criteria; 598 were in NYHA functional class I at the initial visit (age 48 ± 17 years; 31.1% female; peak gradient, 75 ± 40mmHg). At 5-year follow-up, the composite event rate of NYHA functional class I patients was 28% compared with 44% (P< 0.001) in 641 NYHA functional class II patients with oHCM (age 54 ± 16 years; 46.5% female; peak gradient, 83 ± 39mmHg). Left atrial (LA) diameter≥45mm (HR: 1.56 [95%CI: 1.14-2.12]; P = 0.005), female sex (HR: 1.61 [95%CI: 1.16-2.24]; P = 0.003), and older age (HR: 1.21 per 10 years [95%CI: 1.09-1.34]; P< 0.001), but not the magnitude of left ventricular outflow tract obstruction, were associated with a higher risk of the composite outcome in NYHA functional class I patients. Although NYHA functional class I patients with oHCM fared better than NYHA functional class II patients, more than one-fourth experienced adverse events over 5-year follow-up, especially if they were older, female, and/or had LA enlargement. Strategies to reduce the rate of clinical outcomes in NYHA functional class I patients warrant further study.

Point-of-care ultrasound diagnosis of acute valvular emergencies

IntroductionAcute valvular emergencies, a time-sensitive diagnosis, are nearly impossible to diagnose without ultrasound, and missing the diagnosis can significantly impact patient outcomes. Many emergency physicians lack access to echo technicians and may be uncomfortable performing the ultrasound themselves. Approaching the paucity of review articles, none of which are focused for the emergency physician, can be quite daunting, even for those with extensive ultrasound training. ObjectiveOur goal is to provide a simple resource for emergency physicians to utilize ultrasound to diagnose acute valvular emergencies. We created a concise review that includes relevance and approach to the diagnosis, complete with live ultrasound images, reference cards, and focused figures for in-the-moment reference. MethodsA team of ultrasound fellowship-trained emergency medicine physicians determined the highest yield emergent conditions and oversaw the project. Each team member reviewed the etiology, incidence, and level of evidentiary support for each condition and then provided a guide to the appropriate procedure and evaluation with relevant additional guidance. An in-house graphics team was consulted to prepare original, concise figures for easy reference. All sections of the manuscript and figures were reviewed for accuracy and ease of use. DiscussionCritical aortic stenosis, infective endocarditis, left ventricular outflow tract obstruction, mitral stenosis, and mitral regurgitation were identified diagnoses for which ultrasound can provide immediate diagnostic information for emergency physicians. ConclusionThe use of ultrasound in the emergency department setting is a critical adjunct to care for patients with acute valvular emergencies. One should always consider a comprehensive, cardiology-performed echocardiogram in these scenarios.

Prevention of left ventricular outflow tract obstruction in transapical mitral valve replacement: the MitraCut procedure

Prevention of left ventricular outflow tract obstruction in transapical mitral valve replacement: the MitraCut procedure

Hypertrophic obstructive cardiomyopathy-left ventricular outflow tract shapes and their hemodynamic influences applying CMR.

Hypertrophic cardiomyopathy (HCM) is one of the most common genetic cardiac disorders and is characterized by different phenotypes of left ventricular hypertrophy with and without obstruction. The effects of left ventricular outflow tract (LVOT) obstruction based on different anatomies may be hemodynamically relevant and influence therapeutic decision making. Cardiovascular magnetic resonance (CMR) provides anatomical information. We aimed to identify different shapes of LVOT-obstruction using Cardiovascular Magnetic Resonance (CMR). The study consisted of two parts: An in-vivo experiment for shape analysis and in-vitro part for the assessment of its hemodynamic consequences. In-vivo a 3D depiction of the LVOT was created using a 3D multi-slice reconstruction from 2D-slices (full coverage cine stack with 7 slices and a thickness of 5-6mm with no gap) in 125 consecutive HOCM patients (age = 64.17 +/- 12.655; female n = 42). In-vitro an analysis of the LVOT regarding shape and flow behavior was conducted. For this purpose, 2D and 4D measurements were performed on 3D printed phantoms which were based on the anatomical characteristics of the in-vivo study, retrospectively. The in-vivo study identified three main shapes named K- (28.8%), X- (51.2%) and V-shape (10.4%) and a mixed one (9.6%). By analyzing the in-vitro flow measurements every shape showed an individual flow profile in relation to the maximum velocity in cm/s. Here, the V-shape showed the highest value of velocity (max. 138.87cm/s). The X-shape was characterized by a similar profile but with lower velocity values (max. 125.39cm/s), whereas the K-shape had an increase of the velocity without decrease (max. 137.11cm/s). For the first time three different shapes of LVOT-obstruction could be identified. These variants seem to affect the hemodynamics in HOCM.

Combined Norwood and Modified Left-Sided Starnes Procedures for Congenitally Corrected Transposition of the Great Arteries.

The combination of congenitally corrected transposition of the great arteries (ccTGA), Ebstein anomaly of the systemic atrioventricular valve, and critical systemic ventricular outflow tract obstruction is extremely rare. Management of a neonate with these lesions in cardiogenic shock is quite challenging. Tricuspid valve exclusion has been increasingly and successfully used to manage neonatal Ebstein anomaly patients. We extended this idea of tricuspid valve exclusion (modified Starnes) combined with a Norwood Stage 1 operation with a modified systemic to pulmonary artery shunt to successfully manage a neonate with ccTGA, severe systemic atrioventricular valve regurgitation, and critical ventricular outflow tract obstruction.