Subvalvular Apparatus Research Articles

Alterations in Human Mitral Valve Mechanical Properties Secondary to Left Ventricular Remodeling: A Biaxial Mechanical Study.

Secondary mitral regurgitation occurs when a left ventricular problem causes leaking of the mitral valve. The altered left ventricular geometry changes the orientation of the subvalvular apparatus, thereby affecting the mechanical stress on the mitral valve. This in turn leads to active remodeling of the mitral valve, in order to compensate for the ventricular remodeling. In this study, a biomechanical analysis was performed on eight human mitral valves with secondary mitral regurgitation and ten healthy human mitral valves to better understand this pathophysiology and its effect on the mechanical properties of these tissues. Samples were obtained from the anterior and posterior leaflet and used for planar biaxial mechanical experiments. Uniaxial experiments were performed on four groups of mitral valve chords: anterior basal, anterior marginal, posterior basal and posterior marginal chords. The mechanical response of the mitral valve leaflets was fitted to the May-Newman and Yin constitutive model, whereas the material parameters of the third order Ogden model were determined for the chord samples. Next, stiffnesses calculated at low and high stress levels were statistically analyzed. Leaflet samples with secondary mitral regurgitation showed a small thickness increase and a change in anisotropy index compared to healthy control valves. Diseased leaflets were more compliant circumferentially and stiffer radially, resulting in anisotropic samples with the radial direction being stiffest. In addition, chord samples were slightly thicker and less stiff at high stress in secondary mitral regurgitation, when grouped per leaflet type and insertion region. These results confirm mechanical alterations due to the pathophysiological valvular changes caused by left ventricular remodeling. It is important that these changes in mechanical behavior are incorporated into computational models of the mitral valve.

C17 SIMPLIFIED MINIMALLY INVASIVE MITRAL VALVE SURGERY THROUGH A DIRECT VISION TRANSAXILLARY APPROACH: PROCEDURAL AND 30–DAYS OUTCOMES

Abstract Background Minimally invasive cardiac surgery through right mini–thoracotomy access is nowadays an established approach for the treatment of mitral valve pathologies. Several thoracic incisions have been described and different techniques used for cardiopulmonary bypass, myocardial protection and valve exposure. Aim of this study is to review our early results with a minimally invasive approach characterized by a lateral right trans–axillary (TAx) approach and direct vision. Methods Prospectively collected data of patients who underwent mitral valve surgery between 2018 and 2021 were reviewed. Among them, 245 patients underwent minimally invasive mitral valve surgery through TAx access. A single incision at the fourth right intercostal space on the anterior axillary line, 3–to–5 cm in length (Fig 1), allowed a 90° direct view exposure of the mitral valve (Fig 2) and the subvalvular apparatus (Fig 3). A transthoracic clamp was invariably used to achieve the cardioplegic arrest. Results Mean age of the patients was 63 years and the mean EuroSCORE II was 1.6. Regurgitation was the prevalent mitral valve dysfunction (91%). Mitral valve repair was performed in 87% of the cases using several techniques including a combination of annuloplasty, leaflet resection and sliding, placement of neochordae and repair of the commissures. In patients with degenerative disease, the rate of valve repair was 92%. Tricuspid annuloplasty was associated in 10% of the cases. There was no in–hospital death; the rates of postoperative stroke and TIA were 0.4% and 1.2%, respectively. Median mechanical ventilation time was 3 [0–6] hours with 40% of the patients extubated in theatre at the end of the procedure. Median ICU stay was 24 [21–46] hours. Three patients had superficial complications of the thoracic wound and in 7 cases of the groin incision. After a median time of 7 [6–8] days, all the patients were successfully discharged from the hospital. The pre–discharge echocardiogram revealed none or trace residual mitral regurgitation in up to 96% of the patients who underwent mitral valve repair with a mean gradient across the valve of 3 [2–4] mmHg. Conclusions The TAx approach for minimally invasive mitral valve surgery is safe and allows a quick functional recovery. A superb direct view of the mitral apparatus and the ascending aorta, facilitates the exposure and the surgical repair of the valve with no need of any endoscopic nor an endoaortic balloon occlusion system support.

The mitral valve and its contribution to the generation of left ventricular outflow tract obstruction in hypertrophic cardiomyopathy: Considerations for surgeons

Hypertrophic cardiomyopathy is increasingly understood to be a disease that presents not only with septal hypertrophy but also with diverse anomalies of the mitral valve and subvalvular apparatus. In this review, we describe the involvement of the mitral valve in the generation of left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy, and discuss the surgical approaches to managing this complex condition.

ISCHEMIC MITRAL REGURGITATION - TO REPAIR OR REPLACE? LOOKING BEYOND THE VALVE.

Ischemic mitral regurgitation (IMR) is a frequent and serious complication of coronary artery disease, associated with considerable patient increased mortality and morbidity. While the benefits of optimal medical therapy and surgical revascularization, when indicated, are uncontested in moderate to severe cases, the ideal surgical approach to the valve, if any, is yet to be established. Mitral valve repair has established benefits over replacement in primary mitral regurgitation, but its superiority in the treatment of functional regurgitation has not been replicated. Differing outcomes likely stem from the distinct IMR pathophysiology. Unlike its degenerative counterparts, IMR does not derive from direct damage to the valve leaflets, but rather from dysfunction of its sub-valvular apparatus and the left ventricular wall, in the context of acute or chronic ischaemia. Echocardiographic data points to remodelling of the left ventricle, with subsequent papillary muscle displacement, increased leaflet tethering and inefficient coaptation, as the main responsible mechanism for ischemic mitral regurgitation. Neither mitral valve repair nor replacement directly address these issues, with the appearance of the first randomized trials supporting replacement as the more durable option. However, new subvalvular procedures are improving the stability of repair techniques and the debate is long from settled. The purpose of this review is to analyse the currently available data, couple it with our understanding of IMR's pathophysiology and compare the different outcomes for mitral valve repair and replacement.

Thoracoscopic Trans-mitral Septal Myectomy for Hypertrophic Obstructive Cardiomyopathy in the Elderly

BackgroundThe thoracoscopic trans-mitral approach can not only facilitate exposure of the ventricular septum, mitral valve, and subvalvular apparatus, it also enables the surgeons to perform concomitant mitral valve intervention. This study aimed to determine the safety and efficacy of thoracoscopic trans-mitral septal myectomy in elderly patients with hypertrophic obstructive cardiomyopathy (HOCM).MethodsWe reviewed the demographic to clinical characteristics and outcomes of patients who underwent thoracoscopic trans-mitral septal myectomy in our center between April 2019 and April 2021. The population was divided into a younger group (<60 years) and an elderly group (≥60 years).ResultsThere were 46 and 20 patients in the younger and elderly groups, respectively. The majority of patients in the elderly group were female (39.1 vs. 80.0%, P < 0.01). Patients in the elderly group were more likely to be in New York Heart Association Class IV (2.2 vs. 80.0%, P < 0.01). The European System for Cardiac Operation Risk Evaluation II predicted mortality rates were significantly higher (3.97 ± 1.81 vs. 1.62 ± 0.86%, P < 0.01) in the elderly group. In the elderly group, a patient converted to median sternotomy due to left ventricular posterior free wall rupture following septal myectomy and mitral bioprosthetic valve replacement. The patient then underwent double-patch sandwich repair for rupture and mitral mechanical valve replacement and was eventually discharged. All patients in the elderly group were discharged, while one in the younger group died. No patient in the elderly group required permanent pacemaker implantation vs. one in the younger group. Patients in the elderly group were more likely to spend more time in the intensive care unit than those in the younger group (5.44 ± 5.80 days vs. 3.07 ± 2.72, P < 0.05). However, there was no significant intergroup difference in in-hospital mortality or complications. Importantly, the left ventricular outflow tract pressure gradient was significantly decreased from 96.15 ± 32.89 mmHg to 8.2 ± 3.42 mmHg with no residual obstruction in the elderly group. The interventricular septal thickness was significantly decreased from 19.73 ± 3.14 mm to 11.30 ± 2.23 mm. Postoperative mitral regurgitation severity was significantly improved in the elderly group.ConclusionThis study demonstrated that thoracoscopic trans-mitral septal myectomy is a feasible option for selected elderly patients with satisfactory outcomes similar to those of young patients.

The role of surgery for secondary mitral regurgitation and heart failure in the era of transcatheter mitral valve therapies.

The approach to the management of mitral valve (MV) disease and heart failure (HF) has dramatically changed over the last decades. It is well recognized that severe mitral regurgitation secondary to ischemic or non-ischemic cardiomyopathy is associated with an excess risk of mortality. Understanding the impact of the surgical treatment modality on mortality outcomes has been difficult due to the broad spectrum of secondary mitral regurgitation (SMR) phenotypes and lack of randomized surgical clinical trials. Over the last 30 years, surgeons have failed to provide compelling evidence to convince the medical community of the need to treat SMR in patients with severe HF. Therefore, the surgical treatment of SMR has never gained uniform acceptance as a significant option among patients suffering from SMR. Recent evidence from randomized trials in a non-surgical eligible patients treated with transcatheter therapies, has provided a new perspective on SMR treatment. Recently published European and American guidelines confirm the key role of percutaneous treatment of SMR and in parallel, these guidelines reinforce the role of mitral valve surgery in patients who require surgical revascularization. Complex mitral valve repair combining subvalvular apparatus repair along with annuloplasty seems to be a promising approach in selected patients in selected centers. Meanwhile, mitral valve replacement has become the preferred surgical strategy in most patients with advanced heart failure and severe LV remodeling or high risk of recurrent mitral regurgitation. In this comprehensive review, we aimed to discuss the role of mitral surgery for SMR in patients with heart failure in the contemporary era and to provide a practical approach for its surgical management.

Evaluation of an Innovative Device for Mitral Valve Regurgitation: Experimental Acute In Vivo Results.

Objective: Currently, mitral prosthetic rings are intended only to reshape the annulus. We present in vivo results of an innovative device characterized by an intraventricular segment designed to enable artificial chordae implantation and simplify leaflets and subvalvular apparatus correction. Methods: Eight sheep were employed. The first 4 underwent solely device implantation. In the last 4, primary chordae of the anterior leaflet (A2) were torn to induce severe mitral regurgitation. The severed chordae were replaced by 2 pairs of 5-0 Gore-Tex artificial chordae previously measured and anchored to the device bridge. Ease of device and chordae implantation were evaluated, and postprocedural valve competence was verified by postoperative echocardiogram. Results: The procedure was completed in all 8 sheep. In the 4 sheep with induced severe mitral regurgitation, repair could be achieved by means of artificial chordae implantation. Length of the 2 chordae implanted was 21.6 ± 2 mm and 22 ± 3 mm, respectively. The time required to suture the artificial chordae was 2.5 ± 1.2 min. Postoperative echocardiograms showed normal left ventricular ejection fraction and free motion of the mitral leaflets. Mitral regurgitation was absent in 5 cases and trivial in 3. The transvalvular peak pressure gradient was 9.5 ± 6 mm Hg, and mean gradient was 3.7 ± 4 mm Hg. Postprocedural evaluation of the heart and mitral valve showed no damage to the left ventricle wall, valve leaflets, chordae, and papillary muscles. Conclusions: In vivo tests confirm safety of the device, ease of chordal length estimation prior to implantation, short operative time, and no negative impact of the device on mitral leaflet motion, function, and structure.

Geometric differences of the mitral valve apparatus in atrial and ventricular functional mitral regurgitation

BackgroundFunctional mitral regurgitation (FMR) occurs in patients with annular dilation (atrial, aFMR) or patients with left ventricular (LV) disease (ventricular, vFMR). Meticulous understanding of the mechanisms underpinning regurgitation is crucial to optimize therapeutic strategies. MethodsPatients with moderate-severe FMR were identified from a registry of patients referred for transcatheter mitral valve intervention. In addition, controls without cardiovascular disease were identified. Differences in the geometry of the LV and mitral valve apparatus (including leaflet and tenting geometry, papillary muscle displacement and movement, annular dimensions, and dynamism) between atrial and ventricular FMR, and control subjects, were assessed using multiphasic cardiac CT. ResultsOf 183 FMR patients, 18 patients (10%) were found to have aFMR. The remaining patients had either ischemic or non-ischemic ventricular FMR. In aFMR, both increasing LV end-systolic volume (rho 0.701, p ​< ​0.01) and left atrial volume (rho 0.909, p ​< ​0.01) were associated with larger annular area. By contrast, in vFMR larger annular area was most strongly associated with larger left atrial volume (rho 0.63, p ​< ​0.01). In controls, increased annular area was associated with larger LVEDV (rho 0.78, p ​< ​0.01) and LVESV (rho 0.824, p ​< ​0.01), but not left atrial size (rho 0.16, p ​= ​0.45).Ventricular FMR comprised apicolaterally displaced, akinetic posteromedial papillary muscles, resulting in pronounced leaflet tethering, leaflet elongation compared to controls, and only modest relative LA dilatation. Compared to vFMR, aFMR was characterised by marked relative annular dilation, smaller but discernible mitral valve tenting, shorter leaflet lengths when related to annular size, but normal papillary geometry. ConclusionFMR is characterised by multiple changes within the mitral valve complex. Atrial and ventricular FMR differ significantly in terms of the drivers of annular size, and geometry and function of the subvalvular apparatus. This highlights the need to consider these as separate disease entities.

The five phenotypes of tricuspid regurgitation: insight from cluster analysis of clinical and echocardiographic variables

Abstract Funding Acknowledgements Type of funding sources: None. Background Tricuspid regurgitation (TR) is a prevalent valvular lesion with three broad morphologic subtypes: primary due to intrinsic pathology of the valve or subvalvular apparatus; secondary due to pulmonary hypertension; and isolated TR associated with chronic atrial fibrillation. The complex pathophysiological, clinical and echocardiographic features between these subtypes require further investigation. Purpose We aimed to identify the different phenotypes of TR using cluster analysis, and determine differences (if present) in clinical outcomes associated with these phenotypes. Methods We included 13611 patients with ≥ moderate TR, either primary or secondary, in the final analyses. The demographic, clinical and echocardiographic data of these patients were evaluated using Ward’s minimum variance cluster analysis including a total of 38 variables. Survival analysis for all-cause mortality was performed using the Kaplan-Meier method, and groups were compared using the log-rank test. Results The mean age of patients was 72.5 ± 13.4 years, 7590 (56%) were females. The clustering identified 5 distinct phenotypes. Cluster 1 represented "low-risk TR" with lesser severity likely related to chronic atrial fibrillation. This cluster had less severe TR, normal sized right ventricle and fewer comorbidities. Clusters 2-5 represented "higher severity TR", "TR associated with lung disease", "TR associated with coronary artery disease and ischemic cardiomyopathy" and "TR associated with chronic kidney disease" respectively (Figure 1). Cluster 1 had the best overall survival, followed by clusters 2, 3 and 4, and lastly cluster 5, with the worst outcome (Figure 2). Conclusions Cluster analysis identifies 5 phenotypically distinct novel subgroups of TR with differences in all-cause mortality. This phenotype-based classification improves our understanding of interaction of different co-morbidities with this complex valve lesion and can inform clinical decision making. Abstract Figure. Cluster Dendrogram Abstract Figure. Kaplan-Meier survival curves

In Vitro Mitral Valve Model with Unrestricted Ventricular Access: Using Vacuum to Close the Valve and Enable Static Trans-Mitral Pressure

Current in vitro models of the left heart establish the pressure difference required to close the mitral valve by sealing and pressurizing the ventricular side of the valve, limiting important access to the subvalvular apparatus. This paper describes and evaluates a system that establishes physiological pressure differences across the valve using vacuum on the atrial side. The subvalvular apparatus is open to atmospheric pressure and accessible by tools and sensors, establishing a novel technique for experimentation on atrioventricular valves. Porcine mitral valves were excised and closed by vacuum within the atrial chamber. Images were used to document and analyze closure of the leaflets. Papillary muscle force and regurgitant flow rate were measured to be 4.07 N at 120 mmHg and approximately 12.1 ml/s respectively, both of which are within clinically relevant ranges. The relative ease of these measurements demonstrates the usefulness of improved ventricular access at peak pressure/force closure.Graphical abstract

Mitral Plasticity: The Way to Prevent the Burden of Ischemic Mitral Regurgitation?

The ischemic impairment of the left ventricular contractility, followed by an adverse remodeling leading to the displacement of the papillary muscles (PMs), increased tethering forces and loss of valve competence has been the long-term accepted definition of ischemic mitral regurgitation (IMR). Over the years, different approaches of management have attempted to address valve regurgitation, nevertheless failing to achieve satisfactory outcomes. Recent studies have observed some structural and molecular changes of the mitral valve (MV), challenging the concept of a bystander passive to the subvalvular involvement. Indeed, the solely mechanical stretch of the PMs, as in the dilated left ventricle because of the aortic valve regurgitation, is not enough in causing relevant MV regurgitation. This setting triggers a series of structural changes called “mitral plasticity,” leaflets increase in their size among others, ensuring an adequate systolic area closure. In contrast, the ischemic injury not only triggers the mechanical stretch on the subvalvular apparatus but is also a powerful promotor of profibrotic processes, with an upregulation of the transforming growth factor (TGF)-β signaling pathway, leading to a MV with exuberant leaflet thickness and impaired mobility. In this article, we revise the concept of IMR, particularly focusing on the new evidence that supports dynamic changes in the MV apparatus, discussing the consequent clinical insights of “mitral plasticity” and the potential therapeutic implications.

Mid-term results of mitral valve replacement and repair: current clinical experience, technical aspects, and risk factor analysis

Aim: We evaluated the short- and mid-term results of mitral valve replacement (MVR) and mitral valve repair (MV-repair). Methods: In total, 168 patients (mean age 67 ± 11 years) underwent MVR (n = 104) and MV-repair (n = 64). To treat posterior leaflet disease, MV-repair techniques included triangular or quadrangular resection (n = 38), P1-P2 plication (n = 4), side-to side P1-P2 (n = 1), posterior-medial commissure-plasty (n = 1), and annuloplasty (n = 20). A prosthetic ring was implanted in all patients. In the presence of degenerative disease involving the anterior leaflet, extensive myxomatous and/or prolapsing pathology of the entire valve, and/or rheumatic and endocarditis degeneration, surgical orientation was to perform MVR directly. When possible, the sub-valvular apparatus with its papillary muscle was partially preserved. The mean follow-up was 38 ± 22 months. Results: Operative mortality (0.96% vs. 1.56%) and six-year survival (94% vs. 100%) were similar in MVR and MV-repair. The only independent predictor of late survival was advanced age at the operation (79.2 years vs. 66.4 years; P = 0.012). Freedom from redo-operation was 100%. Partial preservation of the sub-valvular apparatus with its papillary muscle during MVR allowed postoperatively a better left ventricular function with similar values achieved with MV-repair (P = 0.05), and it was a protective factor against the development of left ventricular dysfunction during follow-up (P = 0.01). Conclusion: MVR and MV-repair are associated with satisfactory results in the short and medium term. MV-repair to treat posterior leaflet disease is associated with a stable and long-lasting result; MVR allows equally satisfactory results in the presence of more extensive and more complex mitral valve disease. Partial preservation of the sub-valvular apparatus favors a better left ventricular systolic function.

A Surgical Technique to Preserve the Subvalvular Apparatus in Patients Undergoing Mitral Valve Replacement for Severe Ischemic Regurgitation.

Severe functional mitral valve regurgitation should be treated in patients undergoing myocardial revascularization. When replacement is considered the best therapeutic option, preservation of the mitral subvalvular apparatus is crucial, especially in the emergency setting, because of its primary role in preserving geometry and function of left and right ventricles. Here we present a simple and quick technique, where subvalvular apparatus is preserved in toto in patients undergoing mitral valve replacement with a bioprosthesis.

Surgical Management for Systolic Anterior Motion (SAM) of the Mitral Valve in Obstructive Hypertrophic Myopathy.

In patients with obstructive hypertrophic cardiomyopathy, left ventricular outflow tract (LVOT) obstruction can be created by the hypertrophic interventricular septum (IVS) as well as systolic anterior motion (SAM) of the anterior mitral leaflet (AML). Sufficient septal myectomy is a fundamental surgical technique to treat LVOT obstruction, however, direct surgical management for SAM is another key aspect. Besides the hypertrophic IVS, mitral valve, subvalvular apparatus, and papillary muscle may play important role for SAM and several surgical techniques have been proposed to treat SAM in literature. In this review, each surgical technique is classified by the anatomical structure on which the surgical procedure is applied. The AML is the main surgical site and is applied with plication (vertical plication, resection–plication–release strategy), extension (the AML extension, transverse incision of the AML), sutured (edge-to-edge repair, anterior leaflet retention plasty), or traction (floating stitch, papillary muscle-to-anterior annulus stitches, paradoxical stitches, transposition of a directed chorda tendinea to the AML). Height reduction of the posterior mitral valve leaflet and papillary muscle reorientation are other techniques. We should understand theoretical aspects of each technique on correction of anatomical and functional abnormalities of the structure and should apply them under proper indication.

384 Morpho-functional analysis of subvalvular apparatus in mitral valve prolapse and response to dipyridamole stress echocardiography. A pilot study

Abstract Aims Myocardial fibrosis has been found in papillary muscles (PM) and basal segment of left ventricular (LV) inferior-lateral wall in patients with mitral valve prolapse (MVP), which may be due to stretch from valve. Moreover, ST-segment depression is common in patients with MVP, despite low prevalence of epicardial coronary artery disease, and it is attributed to microvascular dysfunction or myocardial stretch. Longitudinal strain (LS) correlates with myocardial fibrosis, while dipyridamole stress echocardiography (DSE) identifies microvascular dysfunction. We aimed at assessing morphology and function of PM and left ventricular walls at rest and during DSE by LS, and at determining prevalence of microvascular dysfunction in patients with MVP. Methods and results Seven consecutive patients with MVP (age 55.4 ± 15.7 years, 57% female) and LV ejection fraction 64 ± 5% underwent DSE. Length and LS of PM were measured at rest and retrospectively compared with those of patients with ischaemic heart disease (n = 8, age 67.1 ± 10.1 years, 37% female) and healthy controls (n = 8, age 39.6 ± 13.3 years, 50% female). LS of PM and LV was also determined at rest and during stress in MVP. Length of PM did not differ among groups, but in MVP, posterior PM was longer than the anterior PM (24 ± 3.8 vs. 20.6 ± 3.6 mm, P = 0.028). Significant difference in resting PM LS was found among groups (overall P = 0.04), with PM LS value in MVP (16.7 ± 7.1%) intermediate between ischaemic (14.2 ± 3.2%) and controls (20.5 ± 2.7%). No difference was found between rest and stress LS of PM in MVP. Global LS tended to increase in MVP during DSE compared to rest (23.1 ± 3.8% vs. 21.1 ± 2.6%, respectively, P = 0.07), while no significant difference between rest and stress LS was found in every LV myocardial segments. Nevertheless, in MVP, LS of LV inferior-lateral wall tended to improve under DSE in patients with mild regurgitation (19.7 ± 4.6 vs. 14.2 ± 5 at rest), but to decrease (16 ± 6.1 vs. 20.3 ± 2.3 at rest) in patients with severe mitral regurgitation (P = 0.006 for interaction). ST-segment depression was elicited by DSE in 29% of MVP. No significant difference in echocardiographic parameters was found between patients with and without ST-segment depression. Conclusions In MVP, sub-valvular apparatus may have peculiar morpho-functional features. DSE does not alter LS of PM, neither of LV walls, except for inferior-lateral wall, which impairs in severe mitral regurgitation. Prevalence of microvascular dysfunction is comparable to that of the general population.

57 Undifferentiated heart sarcoma in young adult: from differential diagnosis to management

Abstract A 34-year-old patient arrived in Emergency Department (ED) with a history of haemoptysis, fever, and night sweats. Echocardiographic examination revealed a large isoechoic thickening that totally encompassed posterior mitral leaflet and which extended contiguously, both inferiorly with subvalvular apparatus with chordal fusion, and superiorly up to left atrial wall. This alteration caused a moderate mitral stenosis with an estimated average gradient of 10–15 mmHg (with possible overestimation due to temporary state of hyperdynamic circulation secondary to anaemization). There also was an anteriorly directed, eccentric jet of mitral regurgitation (2 +/4 + grade).Differential diagnosis of the aforementioned mitral formation included infectious etiology (endocarditic vegetation), pure phlogistic (inflammatory/rheumatic valvulitis), aseptic vegetation, and thrombosis. Transesophageal echocardiographic evaluation showed the extension of the mass into posterior leaflet, the latter completely englobed from commissure to commissure, and cranially adhered to posterior wall of left atrium with estimated dimensions of 1.9 × 12 mm; inferiorly, contiguity with diffusely thickened subvalvular apparatus and chordal fusion, was appreciated. Resulting stenosis was about 13–14 mmHg. Planimetric mitral valve area was estimated to be about 1 cm with associated mild-moderate regurgitation. Global systolic function was preserved with normal segmental kinesis and without significant anomalies affecting other valves. On cardiac magnetic resonance (CMR) with contrast medium, known sleeve thickening of left atrium (maximum thickness 12 mm in lateral area and 7.5 mm at the level of atrial septum) was extended caudocranially for 2.5 cm in lateral area and for 3.2 cm in the side of the atrial septum and with subocclusion of left inferior pulmonary vein. An esophagogastroduodenoscopy (EGDS) was performed with biopsy examination and subsequent histological typing. It concluded for ‘undifferentiated pleomorphic sarcoma’ according to the WHO classification of thoracic tumours. In the stomach there was a diffuse infiltration of lamina propria by atypical, pleomorphic, and large cellular elements. Following cancer evaluation, first-line chemotherapy with ifosfamide and doxorubicin was undertaken. Two days later, due to finding of hyperpyrexia, with a feverish peak of up to 39°, infusion of chemotherapy was interrupted and empiric antibiotic therapy (piperacillin tazobactam) was started. Blood and urine cultures were carried out with search for antigens of legionella and pneumococcus, (MRSA), fungi, and respiratory viruses but all of them were negative for active infection. The following day, an episode of acute respiratory failure occurred, so we performed an urgent chest CT with finding of pneumonia with bilateral pleural effusion and linezolid was started. Because of sudden worsening of clinical conditions, patient was transferred to ICCU (Intensive Cardiac Care Unit) with gradual resolution of desaturation. Cardiac ultrasound imaging, from the very first performed in ED, has been fundamental in documenting the presence of a mass in mitral valve. The timeliness in identifying first and then characterizing it certainly had a positive impact on cancer management, especially in such an aggressive neoplasm in a young patient. Furthermore diagnostic process, corroborated by instrumental data provided by ecocardiography, CT, MRI, PET, and scintigraphy, allowed a better staging of the disease and highlighted other organ involvement in order to manage optimal therapeutic approach.

453 An unexpected finding in an asymptomatic patient planned for non-cardiac surgery

Abstract Aims Left ventricular (LV) aneurysms and pseudoaneurysms are two complications of myocardial infarction, either symptomatic or silent, leading to death or serious morbidity in several cases and often precluding non-cardiac surgery. Here the differential diagnosis is challenging and multimodality imaging is often needed to assess the risk of heart rupture. Methods and results A 71 years-old woman was referred to our Cardiology Department for a preoperative evaluation before lung lobectomy. Her past medical history included multiple cardiovascular risk factors and abdominal aorta aneurysm. She also had severe peripheral arterial disease treated with femoral popliteal bypass surgery in June 2021. In August 2021 she suffered from vascular graft thrombosis requiring a redo surgery. During hospitalization, she was found to have a lung adenocarcinoma. The patient had an unremarkable cardiological history and was asymptomatic. EKG was unremarkable. Transthoracic echocardiography revealed a mildly impaired LV systolic function (EF = 40%), an inferolateral basal wall akinesia and a huge aneurysm with intracavitary thrombus and a wide neck arising right below the posterior mitral annulus. The annular distortion caused by the expanding aneurysm contributed to the development of mitral regurgitation (MR) by displacing the annulus and subvalvular apparatus, resulting in restriction of the posterior mitral valve leaflet, coaptation failure, and moderate MR. Coronary angiography demonstrated a severe 3-vessel coronary artery disease. To further characterize the aneurysm, a cardiac magnetic resonance was carried out. T1 weighted inversion recovery LGE 2-chamber and short axis views showed transmural LGE of the inferior wall and confirmed the presence of a saccular dilatation with thin wall, wide neck (5 × 6 cm) and large intracavitary thrombus at high risk of rupture. Since the presence of metastatic lesions was excluded, the patient underwent cardiac surgery followed by elective lobectomy. Intraoperative findings were consistent with LV aneurysm with a thin myocardial wall. Aneurysm and related thrombus were removed and the orifice was closed with a Dacron patch. In the same setting a myocardial revascularization with two coronary artery bypass grafts was also performed. Surgery was successfully performed without any complication. Intraoperative transesophageal echocardiography clearly revealed the aneurysm and witnessed the reduction of MR after the restoration of LV inferolateral wall geometry. Conclusions Our case highlights the importance of thorough evaluation prior to non-cardiac surgery using multimodality imaging, especially when incidental echocardiographic findings in asymptomatic patients occur. A careful pre-operative assessment of patients planned for non-cardiac surgery is the key to favourable postoperative outcome.

Modes of the bioprosthetic valve failure of the porcine and pericardial valves in the mitral position.

This study was conducted to examine the incidence and modes of the bioprosthetic valve failure of the porcine valve in the mitral position and compare them with those of the pericardial valve. This study included 240 patients (116 men [48.3%]; mean age, 74.87 ± 6.61 years) who underwent mitral valve replacement using the St. Jude Medical Epic bioprosthesis (Epic) (N = 125) or Carpentier-Edwards Perimount (CEP) pericardial valve (N = 115) from January 2000 to December 2020. The median clinical follow-up durations in the Epic and CEP groups were 54.5 months (range, 0-111 months) and 81.5 months (range, 0-194 months), respectively. Structural valve degeneration (SVD) was observed in 9 patients (7.2%) in the Epic group and 11 patients (9.6%) in the CEP group. The rates of freedom from SVD at 3, 5 and 7 years were 97.7%, 90.5% and 75.5% in the Epic group and 100.0%, 96.1% and 90.0% in the CEP group, respectively. SVD reoperation was performed for 7 patients (5.6%) in the Epic group and 6 patients (5.2%) in the CEP group. The rates of freedom from SVD reoperation at 3, 5 and 7 years were 97.7%, 90.5% and 75.5% in the Epic group and 100%, 96.1% and 90.0% in the CEP group, respectively. Epic SVD was predominantly due to leaflet tearing, whereas CEP SVD was predominantly due to leaflet calcification and adhesion to the subvalvular apparatus. SVD of the porcine valve was predominantly due to leaflet tearing. The rate of reoperation for SVD was slightly higher for the porcine valve in the mitral position than for the pericardial valve at adjusted survival analysis.

A Case of Transient Mitral Regurgitation: Not Everything Is Always What It Seems

Mitral regurgitation (MR) is a common form of valvular heart disease that is associated with significant morbidity and mortality. MR can be broadly classified into 2 different categories: primary and secondary MR. Primary MR usually is caused by leaflet abnormalities, whereas secondary MR is a chronic disease secondary to geometric distortion of both the annulus and subvalvular apparatus because of left ventricular remodeling. Without acute changes in loading conditions, myocardial blood flow, or rhythm disturbances, functional MR typically is not transient. In this E-Challenge, the authors show a transient and completely reversible acute and severe form of functional MR with the use of multimodal echocardiography.

Tissues attached to retrieved leadless pacemakers: Histopathological evaluation of tissue composition in relation to implantation time and complications.

Leadless pacemakers (LPs) have proven safe and effective, but device revisions remain necessary. Either replacing the LP or implanting a new adjacent LP is feasible. Replacement seems more appealing, but encapsulation and tissue adhesions may hamper the safety and efficacy of LP retrieval. We determined the incidence and cellular characteristics of tissue adherent to retrieved LPs and the potential implications for end-of-life strategy. All 15 consecutive successful Nanostim LP retrievals in a tertiary center were included. We assessed the histopathology of adherent tissue and obtained clinical characteristics. Adherent tissue was present in 14 of 15 retrievals (93%; median implantation duration 36 months; range 0-96 months). The tissue consisted of fibrosis (n = 2), fibrosis and thrombus (n = 9), or thrombus only (n = 3). In short-term retrievals (<1 year), mostly fresh thrombi without fibrosis were seen. In later retrievals, the tissue consisted of fibrosis often with organizing or lytic thrombi. Fibrosis showed different stages of organization, notably early fibrocellular and later fibrosclerotic tissue. Inflammatory cells were seen (n = 4) without signs of infection. Tricuspid valve material was retrieved in 1 patient after 36 months, resulting in increased tricuspid regurgitation. Our results suggest that fibrosis and thrombus adherent to LPs are common and encapsulate the LP as seen in transvenous pacemakers. LPs may adhere to the tricuspid valve or subvalvular apparatus affecting retrieval safety. The end-of-life strategy should be optimized by incorporating risk stratification for excessive fibrotic encapsulation and adhesions.