Mitral valvuloplasty using real-time three-dimensional transesophageal echocardiography

OBJECTIVE

This study aimed to investigate the structure of the mitral valve in patients undergoing mitral valvuloplasty (MVP) using real-time three-dimensional transesophageal echocardiography (RT-3D-TEE). The main objective was to study the relationship between intraoperative annuloplasty ring size and mitral valve structure dimensions, with a focus on exploring the application value of RT-3D-TEE in MVP.

METHODS

A total of 28 patients with degenerative mitral regurgitation (DMR), who underwent MVP between February and September 2022, as well as 12 normal control cases, were enrolled in this study. The MV annulus and leaflets were quantitatively analyzed using MVN software.

RESULTS

The DMR group exhibited significantly greater dimensions in various parameters of the mitral valve, including the anterolateral-to-posteromedial diameter (DAlPm ), anterior-to-posterior diameter (DAP ), annulus height (HA ), three-dimensional annulus circumference (CA3D ), two-dimensional annulus area (AA2D ), anterior leaflet area (Aant ), posterior leaflet area (Apost ), anterior leaflet length (Lant ), posterior leaflet length (Lpost ), and tenting volume (Vtent ) compared to the control group.

CONCLUSION

Real-time three-dimensional transesophageal echocardiography provides valuable insights into the morphological structure of the mitral valve and lesion location. It can aid in surgical decision-making, validate the success of MVP, and potentially reduce mortality and complications associated with mitral valve repair procedures.

Contemporary Echocardiographic Evaluation of Mitral Regurgitation and Guidance for Percutaneous Mitral Valve Repair

Mitral valve regurgitation (MR) is a multifaceted valvular heart disease. Echocardiography plays a central role in etiology assessment, severity quantification, treatment candidacy, outcome evaluation, and patient follow-up. In this review, we describe the comprehensive echocardiographic assessment of MR, including transthoracic (TTE) and transesophageal (TEE) approaches, 2D and 3D modalities, strain imaging, stress echocardiography, and artificial intelligence (AI) applications. Transcatheter edge-to-edge mitral valve repair (TEER) has been established as a key therapy for patients with severe, symptomatic MR and high surgical risk. TEER is performed under TEE guidance. We outline a practical overview of echocardiographic guidance on TEER.

Mitral Regurgitation in Female Patients: Sex Differences and Disparities

Mitral regurgitation is the most common valvular disease, particularly in older adults. Recent literature has consistently supported that there are significant differences in mitral regurgitation outcomes between male and female patients and that this is likely multifactorial. Numerous sex differences in anatomy and pathophysiology may play a role in delayed diagnoses, referrals, and treatments for female patients. Despite the recognition of these discrepancies in the literature, many guidelines that steer clinical care do not incorporate these factors into society recommendations. Identifying and validating sex-specific diagnostic parameters and increasing the representation of female patients in trials of new mitral regurgitation treatment modalities are key factors in improving outcomes for female patients.

Functional anatomy and echocardiographic assessment in secondary mitral regurgitation

BACKGROUND

Mitral valve apparatus is complex and involves the mitral annulus, the leaflets, the chordae tendinae, the papillary muscles as well as the left atrial and ventricular myocardium. Secondary mitral regurgitation is a consequence of regional or global left ventricle remodeling due to an acute myocardial infarction (75% of cases) or idiopathic dilated cardiomyopathy (25% of cases). It is associated with an increase in mortality and poor outcome. There is a potential survival benefit deriving from the reduction in the degree of severity of mitral regurgitation. So the correction of the valve defect can change the clinical course and prognosis of the patient. The rationale for mitral valve treatment depends on the mitral regurgitation mechanism. Therefore, it is essential to identify and understand the pathophysiology of mitral valve regurgitation.

AIM OF THE STUDY

The aim of this review is to describe the crucial role of transthoracic and trans-esophageal echocardiography, in particular with three-dimensional echocardiography, for the assessment of the severity of secondary mitral regurgitation, anatomy, and hemodynamic changes in the left ventricle. Moreover, the concept that the mitral valve has no organic lesions has been abandoned. The echocardiography must allow a complete anatomical and functional evaluation of each component of the mitral valve complex, also useful to the surgeon in choosing the best surgical approach to repair the valve.

CONCLUSIONS

Echocardiography is the first-line imaging modality for a better selection of patients, according to geometrical modifications of mitral apparatus and left ventricle viability, especially in preoperative phase.

Multimodality imaging for the management of patients with primary mitral regurgitation

Advanced cardiac imaging (ACI), including myocardial deformation imaging, 3D echocardiography and cardiac magnetic resonance, overcomes the limitations of conventional echocardiography in the assessment of patients with primary mitral regurgitation (MR). They enable a more precise MR quantification and reveal early changes before advanced and irreversible remodeling with depressed heart function occurs. ACI permits a thorough analysis of mitral valvular anatomy and MR mechanisms (important for planning and guiding percutaneous and surgical procedures) and helps to identify structural and functional changes coupled with a high arrhythmogenic potential, especially the occurrence of atrial fibrillation and heart failure development. The key question is how the data provided by ACI can improve the current management of primary MR.

3D Echo Characterization of Proportionate and Disproportionate Functional Mitral Regurgitation before and after Percutaneous Mitral Valve Repair

BACKGROUND

The impact of percutaneous mitral valve repair (PMVr) on long-term prognosis in patients with functional mitral regurgitation (FMR) is still unclear. Recently, a new conceptual framework classifying FMR as proportionate (P-MR) and disproportionate (D-MR) was proposed, according to the effective regurgitant orifice area/left ventricular end-diastolic volume (EROA/LVEDV) ratio. The aim was to assess its possible influence on PMVr efficacy.

METHODS

A total of 56 patients were enrolled. MV annulus, LV volumes and function were assessed. Global longitudinal strain (GLS) was also calculated. Patients were divided into two groups, according to the EROA/LVEDV ratio. Echocardiographic follow-up was performed after 6 months, and adverse events were collected after 12 months.

RESULTS

D-MR patients (n = 28, 50%) had a significantly more elliptical MV annulus (p = 0.048), lower tenting volume (p = 0.01), higher LV ejection fraction (LVEF: 32 ± 7 vs. 26 ± 5%, p = 0.003), lower LVEDV, LV end-systolic volume (LVESV) and mass (LVEDV/i: 80 ± 20 vs. 126 ± 27 mL, p = 0.001; LVESV/i: 60 ± 20 vs. 94 ± 23 mL, p < 0.001; LV mass: 249 ± 63 vs. 301 ± 69 gr, p = 0.035). GLS was more impaired in P-MR (p = 0.048). After 6 months, P-MR patients showed a higher rate of MR recurrence. After 12 months, the rate of CV death and rehospitalization due to HF was significantly higher in P-MR patients (46% vs. 7%, p < 0.001). P-MR status was strongly associated with CV death/rehospitalization (HR = 3.4, CI 95% = 1.3-8.6, p = 0.009).

CONCLUSIONS

Patients with P-MR seem to have worse outcomes after PVMr than D-MR patients. Our study confirms the importance of the EROA/LVEDV ratio in defining different subsets of FMR based on the anatomical characteristic of MV and LV.

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.

Two and Three-Dimensional Echocardiography in Primary Mitral Regurgitation: Practical Hints to Optimize the Surgical Planning

Primary mitral regurgitation (MR) is the second most common valvular disease, characterized by a high burden in terms of quality of life, morbidity, and mortality. Surgical treatment is considered the best therapeutic strategy for patients with severe MR, especially if they are symptomatic. However, pre-operative echocardiographic evaluation is an essential step not only for surgical candidate selection but also to avoid post-operative complications. Therefore, a strong collaboration between cardiologists and cardiac surgeons is fundamental in this setting. A meticulous pre-operative echocardiographic exam, both with transthoracic or transesophageal echocardiography, followed by a precise report containing anatomical information and parameters should always be performed to optimize surgical planning. Moreover, intraoperative transesophageal evaluation is often required by cardiac surgeons as it may offer additive important information with different hemodynamic conditions. Three-dimensional echocardiography has recently gained higher consideration and availability for the evaluation of MR, providing more insights into mitral valve geometry and MR mechanism. This review paper aims to realize a practical overview on the main use of basic and advanced echocardiography in MR surgical planning and to provide a precise checklist with reference parameters to follow when performing pre-operative echocardiographic exam, in order to aid cardiologists to provide a complete echocardiographic evaluation for MR operation planning from clinical and surgical point-of-view.

Hypertrophic Obstructive Cardiomyopathy: Discrepancy Between Hemodynamic Measurements in the Cardiac Laboratory and Operating Room Is to Be Expected

OBJECTIVES

It is not uncommon to observe some discrepancy in hemodynamic values characterizing left ventricular outflow tract (LVOT) obstruction preoperatively and in the operating room in patients with hypertrophic obstructive cardiomyopathy. Interpretation of this discrepancy can be challenging. To clarify the extent of the discrepancy, the authors compared hemodynamic variables in patients undergoing septal myectomy at the time of preoperative and intraoperative evaluation.

DESIGN

Retrospective study.

SETTING

Single academic medical center.

INTERVENTIONS

Medical records review, study group-173 patients.

MEASUREMENTS AND MAIN RESULTS

While there was no statistically significant difference in resting peak LVOT gradients by preoperative transthoracic echocardiography (TTE) compared to intraoperative transesophageal echocardiography (46 mmHg [19-87 mmHg] v 36 mmHg [16-71 mmHg], p = 0.231), the former were higher compared to direct needle-resting LVOT gradient measurements before myectomy (49 mmHg [19-88 mmHg] v 32 mmHg [14-67 mmHg], p = 0.0022). The prevalence of systolic anterior motion was high (94.6% v 91.6%, P = 1.000) both on pre- and intraoperative evaluation. The incidence of moderate/severe mitral was higher intraoperatively (p < 0.0001). Pulmonary artery systolic pressures measured by pulmonary artery catheter provided higher values compared to preoperative TTE estimate (39 mmHg [34-45 mmHg] v 34 mmHg [28-41 mmHg], p < 0.0001).

CONCLUSIONS

Discrepancy between hemodynamic measurements in the cardiac laboratory and operating room is common and generally should not affect planned patients' care. These changes in hemodynamics might be explained by preoperative fasting, anesthetic agents, volume shifts while supine, and positive-pressure ventilation, as well as the difference in measurement techniques.

Case Report: Streptococcus alactolyticus as a Rare Pathogen of Mitral Endocarditis

Streptococcus bovis/Streptococcus equinus complex (SBSEC) is a group of non-enterococcal group D Streptococci that colonizes both humans and animals. Due to gastrointestinal disease, they can switch in opportunistic pathogens passing through intestinal mucosal barrier and may cause bacteremia and distant organs damage. Despite infective endocarditis (IE), extra-cardiac manifestations of organs damage include osteoarticular infections, meningitis, and biliary infections among others; moreover, the association with colonic pathological lesions has been largely described. Streptococcus alactolyticus as a species included in SBSEC may share pathophysiological similarities, although it represents an extremely rare cause of distant organ infections, being reported in literature as causative agent of IE in only two other cases. We describe a case of 69-year-old male admitted to our institution due to mild-moderate dyspnea and fever, affected by cervico-brachialgia for 3 weeks. Streptococcus alactolyticus was identified as causative agent of IE on the mitral valve, causing severe regurgitation.

Ischemic Mitral Regurgitation: A Multifaceted Syndrome with Evolving Therapies

Dysfunction of the left ventricle (LV) with impaired contractility following chronic ischemia or acute myocardial infarction (AMI) is the main cause of ischemic mitral regurgitation (IMR), leading to moderate and moderate-to-severe mitral regurgitation (MR). The site of AMI exerts a specific influence determining different patterns of adverse LV remodeling. In general, inferior-posterior AMI is more frequently associated with regional structural changes than the anterolateral one, which is associated with global adverse LV remodeling, ultimately leading to different phenotypes of IMR. In this narrative review, starting from the aforementioned categorization, we proceed to describe current knowledge regarding surgical approaches in the management of IMR.

Novelties in 3D Transthoracic Echocardiography

Cardiovascular imaging is developing at a rapid pace and the newer modalities, in particular three-dimensional echocardiography, allow better analysis of heart structures. Identifying valve lesions and grading their severity represents crucial information and nowadays is strengthened by the introduction of new software, such as transillumination, which provide detailed morphology descriptions. Chambers quantification has never been so rapid and accurate: machine learning algorithms generate automated volume measurements, including left ventricular systolic and diastolic function, which is extremely important for clinical decisions. This review provides an overview of the latest innovations in the echocardiography field, and is helpful by providing a better insight into heart diseases.