Relationship between mitral annulus function and mitral regurgitation severity and left atrial remodelling in patients with primary mitral regurgitation

Left atrial and left ventricular strain dynamics with echocardiography in asymptomatic children with mitral regurgitation

Left atrial (LA) dilatation is a strong predictor of cardiovascular morbidity and mortality. Strain parameters evaluating LA functions have gained importance in assessing cardiovascular health. This study aimed to investigate the relationship between LA and left ventricular (LV) strain, using speckle-tracking echocardiography, and assess the impact of vena contracta on LV functioning in asymptomatic children with mitral regurgitation. We evaluated 45 asymptomatic mitral regurgitation patients, categorized as mild, moderate, and severe. LV strain was significantly lower in the moderate group (-17.8 ± 3.7%) and further reduced in the severe group (16 ± 2.1%) compared to the reference group (20.5 ± 6.2%). Conversely, LA reservoir strain was higher in the severe and moderate groups (38 ± 12.9% and 40.7 ± 9.5%, respectively) compared to the controls (31.3 ± 7.5%; p < 0.0001). The severe group also displayed a milder depression of contraction (12.2%) compared to the moderate group (13 ± 7.2%). In the moderate and severe groups, LV strain correlated significantly with vena contracta (r=-0.858; p = 0.04), with vena contracta emerging as the only independent predictor for LV longitudinal strain. ROC curve analysis indicated a cut-off value > 5.65 mm for vena contracta, which had a positive predictive value of 75% for predicting LV function impairment. In conclusion, this study emphasizes the significance of assessing LA and ventricular strain in asymptomatic children with mitral regurgitation. Furthermore, vena contracta with diameters greater than 5.6 mm may alert clinicians to the possibility of LV function impairment. These findings offer valuable insights for the follow-up and management of paediatric patients with mitral regurgitation, enabling early detection of potential complications and improved patient outcomes.

Left atrial strain analysis in the realm of pediatric cardiology: Advantages and implications

BACKGROUND

Left atrial (LA) strain analysis has emerged as a noninvasive technique for assessing LA function and early detection of myocardial deformation. Recently, its application has also shown promise in the pediatric population, spanning diverse cardiac conditions that demand accurate and sensitive diagnostic measures.

OBJECTIVE

This research article endeavors to explore the role of LA strain parameters and contribute to the growing body of knowledge in pediatric cardiology, paving the way for more effective and tailored approaches to patient care.

METHODS

A comprehensive literature review was conducted to gather evidence from studies using echocardiographic strain imaging techniques across pediatric populations.

RESULTS

LA strain parameters exhibited greater sensitivity than conventional atrial function indicators, with early detection of diastolic dysfunction and LA remodeling in pediatric cardiomyopathy, children with multisystem inflammatory syndrome, rheumatic heart disease, as well as childhood renal insufficiency and obesity offering prognostic relevance as potential markers in these pediatric subpopulations. However, there remains a paucity of evidence concerning pediatric mitral valve pathology, justifying further exploration.

CONCLUSION

LA strain analysis carries crucial clinical and prognostic implications in pediatric cardiac conditions, with reliable accuracy and sensitivity to early functional changes.

3D mitral annulus echocardiography assessment in patients affected by degenerative mitral regurgitation who underwent mitral valve repair with flexible band

BACKGROUND

Degenerative mitral valve (MV) regurgitation (DMR) shows significative mitral annulus (MA) alterations; mitral valve repair (MVR) seeks to restore annular geometry and function, and the current use of flexible band seams to respect most annular mobility reducing parietal stress. Parameters of MV geometry obtained by 3D transesophageal echocardiography (3D-TTE) analysis are crucial for surgical planning and postoperative success. The aim of this study was to assess, by means of a dedicated software, the variations of MA geometry and function in patients affected by DMR compared to controls and after MVR with flexible band.

METHODS

We enrolled 32 patients (cases) with severe DMR who underwent MVR using flexible band; we compare this group with 20 controls. The TEE with 3D MV images acquisition was performed in both groups and then analyzed in postprocessing by using a dedicated software.

RESULTS

There were no anthropometrics differences between cases and controls, both presented normal left ventricular ejection fraction. DMR group showed a significant increase of annulus dimensional parameters (p = .001) and alteration of nonplanarity comparing to controls (p < .05). The annuloplasty with flexible band induces a considerable reduction of MV dimensions comparing to preoperative data and restores physiological mobility and nonplanarity. There were no statistical differences between postoperative DMR and controls data, except for nonplanarity parameters (p ~.05), maybe influenced by hemodynamic settings.

CONCLUSIONS

MVR with annuloplasty using flexible band appears able to reinstate a more physiological anatomic conformation of the MA, without compromising its dynamic properties.

Left Atrial Volume Correlates with Mitral Annulus Size: An MDCT Study

Aim: Although the association between left ventricular dilation and mitral annulus dilation is well understood, the potential variation in the size of the mitral annulus during dilation of the left atrium is currently unknown. In order to investigate the link between the two variables, we used multidetector computed tomography (MDCT) and looked at patients who had a dilated left atrium, assessing if the mitral valve also dilates. Materials and Methods: The study included 107 patients with paroxysmal and persistent atrial fibrillation, in whom catheter ablation was performed using pulmonary vein isolation ± atrial substrate modification. Eighty patients were male (74.8%), with a mean age of 55.8 years (±9.87 with a minimum age of 26 years and a maximum age of 79 years), of which 57.1% had paroxysmal AF and the rest had persistent fibrillation. All the patients underwent multiple-detector CT (MDCT) with contrast medium before the ablation. CT images were integrated into the three-dimensional mapping system CARTO 3, after which the diameters of the mitral annulus, area, and circumference were measured. Left atrial size was evaluated by measuring the diameters, area, and volume. Results: The left atrial area was 247 ± 65.7 cm2 and the left atrial volume was 139 ± 56.3 mL. The transverse mitral annulus (MA) was 29.9 ± 5.3 mm and the longitudinal diameter was 41.9 ± 7.6 mm. The MA circumference and area were 15.0 ± 3.5 cm and 14.2 ± 4.6 cm2, respectively. The following statistically significant correlation was identified between the dimensions of the mitral annulus and the diameters of the left atrium: the transverse mitral annulus correlates with the antero-posterior (AP) LA diameter (R = 0.594, p < 0.01) and the longitudinal MA diameter correlates with the latero-lateral (LL) LA diameter (R = 0.576, p < 0.01). Furthermore, the MA area correlates with the LA volume (R = 0.639, p < 0.001). Conclusions: The volume of the left atrium correlates with the area of the mitral annulus. In patients with paroxysmal and persistent AF, an increase in left atrial dimensions is further associated with an increase in mitral valve dimensions.

3D Echocardiography for Rheumatic Heart Disease Analysis: Ready for Prime Time

Rheumatic heart disease (RHD) remains to be a very important health issue worldwide, mainly in underdeveloped countries. It continues to be a leading cause of morbidity and mortality throughout developing countries. RHD is a delayed non-suppurative immunologically mediated inflammatory response to the throat infection caused by a hemolytic streptococcus from the A group (Streptococcus pyogenes). RHD keeps position 1 as the most common cardiovascular disease in young people aged <25 years considering all the continents. The disease can lead to valvular cardiac lesions as well as to carditis. Rheumatic fever valvular injuries lead most commonly to the fusion and thickening of the edges of the cusps and to the fusion, thickening, and shortening of the chordae and ultimately to calcification of the valves. Valvular commissures can also be deeply compromised, leading to severe stenosis. Atrial and ventricular remodeling is also common following rheumatic infection. Mixed valvular lesions are more common than isolated valvular disorders. Echocardiography is the most relevant imaging technique not only to provide diagnostic information but also to enable prognostic data. Further, it presents a very important role for the correction of complications after surgical repair of rheumatic heart valvulopathies. Three-dimensional (3D) echocardiography provides additional anatomical and morphofunctional information of utmost importance for patients presenting rheumatic valvopathies. Accordingly, three-dimensional echocardiography is ready for routine use in patients with RHD presenting with valvular abnormalities.

Speckle tracking echocardiography in primary mitral regurgitation: should we reconsider the time for intervention?

Thanks to the improvement in mitral regurgitation (MR) diagnostic and therapeutic management, with the introduction of minimally invasive techniques which have considerably reduced the individual surgical risk, the optimization of the timing for MR “open” or percutaneous surgical treatment has become a main concern which has highly raised scientific interest. In fact, the current indications for intervention in MR, especially in asymptomatic patients, rely on echocardiographic criteria with high severity cut-offs that are fulfilled only when not only mitral valve apparatus but also the cardiac chambers’ structure and function are severely impaired, which results in poor benefits for post-operative clinical outcome. This led to the need of new indices to redefine the optimal surgical timing in these patients. Speckle tracking echocardiography provides early markers of cardiac dysfunction due to subtle myocardial impairment; therefore, it could offer pivotal information in this setting. In fact, left ventricular and left atrial strains have already shown evidence about their usefulness in recognizing MR impact not only on symptoms and quality of life but also on cardiovascular events and new-onset atrial fibrillation in these patients. Moreover, right ventricular strain could be used to identify those patients with advanced cardiac damage and different grades of right ventricular dysfunction, which entails higher risks for cardiac surgery that could overweigh surgical benefits. This review aims to describe the importance of reconsidering the timing of intervention in MR and to analyze the potential additive value of speckle tracking echocardiography in this clinical setting.

Precision medicine in human heart modeling : Perspectives, challenges, and opportunities

Precision medicine is a new frontier in healthcare that uses scientific methods to customize medical treatment to the individual genes, anatomy, physiology, and lifestyle of each person. In cardiovascular health, precision medicine has emerged as a promising paradigm to enable cost-effective solutions that improve quality of life and reduce mortality rates. However, the exact role in precision medicine for human heart modeling has not yet been fully explored. Here, we discuss the challenges and opportunities for personalized human heart simulations, from diagnosis to device design, treatment planning, and prognosis. With a view toward personalization, we map out the history of anatomic, physical, and constitutive human heart models throughout the past three decades. We illustrate recent human heart modeling in electrophysiology, cardiac mechanics, and fluid dynamics and highlight clinically relevant applications of these models for drug development, pacing lead failure, heart failure, ventricular assist devices, edge-to-edge repair, and annuloplasty. With a view toward translational medicine, we provide a clinical perspective on virtual imaging trials and a regulatory perspective on medical device innovation. We show that precision medicine in human heart modeling does not necessarily require a fully personalized, high-resolution whole heart model with an entire personalized medical history. Instead, we advocate for creating personalized models out of population-based libraries with geometric, biological, physical, and clinical information by morphing between clinical data and medical histories from cohorts of patients using machine learning. We anticipate that this perspective will shape the path toward introducing human heart simulations into precision medicine with the ultimate goals to facilitate clinical decision making, guide treatment planning, and accelerate device design.

Changes in mitral valve geometry after percutaneous valve repair with the MitraClip® System

The aim of our study was to assess the anatomical changes of the mitral valve apparatus after percutaneous repair with the MitraClip® system. We included consecutive patients who underwent MitraClip® implantation in our center. Patients were assessed by 2- and 3-dimensional transesophageal echocardiography, acquired before and immediately after MitraClip® implantation. Off-line images analysis was performed to assess mitral annular diameters (antero-posterior and inter-commisural), area and circumference. Mitral tenting distance, area and volume were evaluated for functional mitral regurgitation. Patients had a 2-dimensional transthoracic echocardiography at follow-up (8 months). 38 patients with successful results (residual mitral regurgitation grade ≤ II) were included. The anteroposterior annulus diameter (ADP) decreased (from 35 ± 5 to 28 ± 5 mm, p < 0.001) with smaller decreases in the annular area and circumference and in the inter-commissural diameter. Annular ellipticity improved. The reduction in APD and tenting distance was sustained at follow-up. Successful percutaneous mitral valve repair with the MitraClip® system induces a stable change in mitral valve geometry mainly at the ADP, suggesting a significant annuloplasty that contributes to the reduction of mitral regurgitation.

Left atrial strain as a pre-operative prognostic marker for patients with severe mitral regurgitation

BACKGROUND

In patients with severe mitral regurgitation (MR), additional echocardiographic indices could be helpful to optimize surgical timing before irreversible left heart myocardial dysfunction has occurred. We investigated the correlation of left atrial (LA) strain by speckle tracking echocardiography with prognosis after mitral surgery for severe MR, and its association with LA fibrosis.

METHOD

71 patients with primary severe MR undergoing pre-operative echocardiographic assessment were initially enrolled. Exclusion criteria were: other valvular disease>moderate, history of coronary artery disease, heart failure (HF), hypertrophic cardiomyopathy, left bundle branch block, previous pacemaker implantation, heart transplantation, poor acoustic window. The primary endpoint was the occurrence of composite events (HF and mortality); the secondary endpoint was post-operative functional capacity (NYHA and Borg CR10 class). LA fibrosis was assessed by atrial biopsy specimens in a subset of patients.

RESULTS

Of 65 eligible patients, the primary endpoint occurred in 30 patients (medium follow-up: 3.7 ± 1 years for event-group, 6.8 ± 1 years for non-event group). After Kaplan-Meier analysis, peak atrial longitudinal strain (PALS) provided good risk stratification (5-year event-free survival:90 ± 5% for PALS≥21% vs 30 ± 9% for PALS<21%, p < 0.0001); it was an independent and incremental predictor of outcome in four multivariate Cox adjusted models. There was also an association between PALS and the secondary endpoint (NYHA: r² = 0.11, p = 0.04; Borg CR10: r² = 0.10, p = 0.02) and an inverse correlation between PALS<21% and LA fibrosis (r² 0.80, fibrosis: 76.6 ± 20.7% vs 31.9 ± 20.8%;p < 0.0001).

CONCLUSIONS

Global PALS emerged as a reliable predictor of outcome and functional capacity for severe primary MR, and as a marker of LA fibrosis.

Degenerative mitral regurgitation

PURPOSE OF REVIEW

Degenerative mitral regurgitation (DMR) continues to be an important cause of morbidity and mortality with surgical mitral valve repair remaining the gold standard for the treatment of severe disease. The purpose of this review is to summarize recent advances in the understanding of DMR as well as the progress made in its assessment with a focus on imaging techniques.

RECENT FINDINGS

Recent insights into the anatomy and physiology of DMR challenge the assumption that fibroelastic deficiency and Barlow disease are part of a single DMR spectrum. Advances in echocardiography and cardiovascular MRI have the potential to improve quantification of mitral regurgitation, provide unique information on prognosis and impact of DMR, further the association between DMR and arrhythmic risk and aide in decision-making for DMR treatment.

SUMMARY

With growing interest in the use of noninvasive transcatheter therapies in the mitral valve space, comprehensive assessment of the mitral valve is critical to instruct decision-making and guide therapeutic strategy.

Relation of Mitral Annulus and Left Atrial Dysfunction to the Severity of Functional Mitral Regurgitation in Patients with Dilated Cardiomyopathy

METHODS

56 patients (58 ± 17 years, 42 men) with DCM and FMR and 52 controls, prospectively enrolled, underwent 3DTTE dedicated for mitral valve (MV), LA, and left ventricle (LV) quantitative analysis.

RESULTS

Patients with FMR vs. controls presented increased MA size and sphericity during the entire systole, whereas MA fractional area change (MAFAC) and MA displacement were decreased (15 ± 5 vs. 28 ± 5%; and 5 ± 3 vs. 10 ± 2 mm, p < 0.001). In patients with moderate/severe FMR, MA diameters correlated with PISA radius, EROA, and regurgitant volume (Rvol), as also did the MA area (with PISA radius, EROA, and Rvol: r = 0.48, r = 0.58, and r = 0.47, p < 0.05). MAFAC correlated inversely with EROA and Rvol (r = -0.32 and r = -0.35, p < 0.05), with both active and total LA emptying fractions and with LV ejection fraction as well. In a stepwise multivariate regression model, decreased MAFAC and increased LA volume independently predicted patients with severe FMR.

CONCLUSIONS

Patients with DCM and FMR have MA geometry remodeling and contractile dysfunction, correlated with the severity of FMR. MA contractile dysfunction correlated with both LA and left LV pumps dysfunctions and predicted patients with severe FMR. Our results provide new insights that might help with better selection of patients for MV transcatheter procedures.

Dynamic changes of mitral annulus in patients with degenerative mitral regurgitation and chronic atrial fibrillation undergoing mitral valve reconstruction

OBJECTIVE

This study was designed to assess structural and dynamic changes in the mitral annulus in patients before mitral valve reconstruction for degenerative mitral regurgitation with or without chronic atrial fibrillation.

METHODS

One hundred and fifty one consecutive patients undergoing mitral valve reconstruction for mitral regurgitation due to myxomatous disease between July 2013 and May 2016 were included. Of these, 117 had a sinus rhythm (SR group) and 34 had chronic AF (AF group). Patients who underwent aortic surgery and were found to have no underlying cardiac valve disease nor coronary artery disease were included as the control group (n = 20). Real-time three-dimensional trans-esophageal echocardiography (3D-TEE) was used to assess mitral annulus shape, size, and movements.

RESULTS

Annular areas in the control group were the smallest of the three groups and changed considerably through the cardiac cycle. Mean anteroposterior and intercommissural diameter measurements in the SR group were significantly larger but oscillated less than in the control group. Those diameters were the largest in the AF group and oscillated very little. Dilatation of the annulus in the AF and SR groups was accompanied by flattening and marked loss of oscillation in the height-to-intercommissural-width ratio which should peak in early systole.

CONCLUSIONS

In patients with degenerative mitral regurgitation undergoing mitral valve surgery, preoperative chronic atrial fibrillation is associated with more progressed annular remodeling, characterized by marked enlargement of annular area, circumference, and anteroposterior diameter.

Mitral Regurgitation: Anatomy, Physiology, and Pathophysiology-Lessons Learned From Surgery and Cardiac Imaging

The normal mitral valve is a dynamic structure that permits blood to flow from the left atrial (LA) to left ventricle (LV) during diastole and sealing of the LA from the LV during systole. The main components of the mitral apparatus are the mitral annulus (MA), the mitral leaflets, the chordae tendineae, and the papillary muscles (PM) (Figure 1). Normal valve function is dependent on the integrity and normal interplay of these components. Abnormal function of any one of the components, or their interplay can result in mitral regurgitation (MR). Understanding the anatomy and physiology of all the component of the mitral valve is important for the diagnosis, and for optimal planning of repair procedures. In this review we will focus first on normal anatomy and physiology of the different parts of the mitral valve (MA, leaflets, chordae tendineae, and PM). In the second part we will focus on the pathologic anatomic and physiologic derangements associated with different types of MR.

Predictors of mitral annulus enlargement? A real-time three-dimensional transesophageal study

BACKGROUND

Mitral annulus (MA) enlargement can be observed in various cardiac conditions but respective influence of left atrial (LA) and left ventricle (LV) size remained unclear.

METHODS

In 120 patients who underwent a clinically indicated 3D-transesophageal-echocardiography, 30 atrial fibrillation (AF), 30 secondary mitral regurgitation (SMR), 30 primary myxomatous mitral regurgitation (PMR) and 30 mitral stenosis (MS), we evaluated the association between MA area (MA-area) and LA volume (LAvol) measured using the biplane area-length method, end-diastolic (LVEDV) and end-systolic (LVESV) volumes measured using the biplane Simpson method. MA-area was measured based on 3D datasets using QLab10.

RESULTS

MA-area was correlated to LVEDV (r = 0.42, p < 0.0001), LVESV (r = 0.29, p = 0.001) but more markedly to LAvol (r = 0.62, p < 0.0001). Correlation between MA-area and LAvol was sustained in all subsets whereas MA-area was not correlated to LVEDV and LVESV in patients with SMR and with PMR (all p > 0.10). In multivariate analysis main predictors of MA-area were LAvol (p < 0.0001) and myxomatous etiology of MR (p = 0.0003) followed by LVEDV (p = 0.006) and LVESV (p = 0.02).

CONCLUSION

In a population of patients with a wide range of LA/LV size related to various conditions, LA volume and myxomatous MR etiology appeared as main predictors of MA size whereas LV size had a more modest influence.

Validation of a Holographic Display for Quantification of Mitral Annular Dynamics by Three-Dimensional Echocardiography

BACKGROUND

Three-dimensional (3D) echocardiography with multiplanar reconstruction (MPR) is used clinically to quantify the mitral annulus. MPR images are, however, presented on a two-dimensional screen, calling into question their accuracy. An alternative to MPR is an autostereoscopic holographic display that enables in-depth visualization of 3D echocardiographic data without the need for special glasses. The aim of this study was to validate an autostereoscopic display using sonomicrometry as a gold standard.

METHODS

In 11 anesthetized open-chest pigs, sonomicrometric crystals were placed along the mitral annulus and near the left ventricular apex. High-fidelity catheters measured left atrial and ventricular pressures. Adjustments of pre- and afterload were done by constriction of the inferior vena cava and the ascending aorta, respectively. Three-dimensional epicardial echocardiography was obtained from an apical view and converted to the autostereoscopic display. A 3D virtual semitransparent annular surface (VSAS) was generated to measure commissure width (CW), septal-lateral length, area of the mitral annular surface, nonplanarity angle, and the annular height-to-commissure width ratio in mid-systole and late diastole.

RESULTS

Mitral annular measurements from the 3D VSAS derived from the 3D echocardiographic images and autostereoscopic display correlated well with sonomicrometry over a range of loading conditions: CW length (r = 0.98, P < .00001), septal-lateral length (r = 0.98, P < .00001), annular surface area (r = 0.93, P < .001), nonplanarity angle (r = 0.87, P < .001), and annular height-to-commissure width ratio (r = 0.85, P < .01). The 3D VSAS showed better agreement with the sonomicrometric measurements compared with MPR.

CONCLUSIONS

Mitral annular measurements using 3D VSAS correlate well with sonomicrometry over a range of loading conditions and may represent a powerful tool for noninvasive quantification of mitral annular dynamics.

Imaging 4D morphology and dynamics of mitral annulus in humans using cardiac cine MR feature tracking

Feature tracking in cine cardiac magnetic resonance (CMR) is a quantitative technique to assess heart structure and function. We investigated 4-dimensional (4D) dynamics and morphology of the mitral annulus (MA) using a novel tracking system based on radially rotational long-axis cine CMR series. A total of 30 normal controls and patients with mitral regurgitation were enrolled. The spatiotemporal changes of the MA were characterized by an in-house developed program. Dynamic and morphological parameters extracted from all 18 radial slices were used as references and were compared with those from subsequently generated sub-datasets with different degrees of sparsity. An excellent agreement was found among all datasets including routine 2-, 3- and 4-chamber views for MA dynamics such as peak systolic velocity (Sm) and mitral annular plane systolic excursion (MAPSE). MA morphology for size and shape was addressed adequately by as few as 6 radial slices, but poorly by only three routine views. Patients with regurgitation showed significantly reduced mitral dynamics and mild annular deformation, which was consistent between three routine views and 18 reference slices. In conclusion, feature tracking cine CMR provided a comprehensive and distinctive profile for 4D MA dynamics and morphology, which may help in studying different cardiac diseases.