Effect of Mitral Valve Repair on Mitral-Aortic Coupling: A Real-Time Three-Dimensional Transesophageal Echocardiography Study

Echocardiographic Evaluation of Successful Mitral Valve Repair or Need for a Second Pump Run in the Operating Room

Detailed preoperative and intraoperative echocardiographic assessment of the mitral valve apparatus is critical for a successful repair. The recent advent of 3-dimensional transesophageal echocardiography has added an extra pivotal role to transesophageal echocardiography in the assessment of mitral apparatus and mitral regurgitation. Because surgeons must rapidly decide whether cardiopulmonary bypass should be continued to be weaned off or a second pump run should be selected, the echocardiographer conducting intraoperative transesophageal echocardiography is required to be trained according to a certain algorithm. This review summarizes the current clinical role of intraoperative transesophageal echocardiography in mitral valve repair in the operating room.

Mitral Valve Replacement: A Review of Current Practices and Considerations in Low and High-Risk Patients

Mitral Regurgitation (MR) is the most common form of severe valvular disease occurring in developed countries, being caused either primarily on its own or secondary to cardiac disease. Surgical intervention is required for the correction of MR, which could include the replacement or repair of the affected valve. Transcatheter Mitral Valve Replacement (TMVR) in selected patients is of increasing importance, especially after the success of Transcatheter Aortic Valve Replacement (TAVR). TMVR can be divided into three types i.e., valve-in-valve (ViV) for severe mitral valve disease, valve-in-ring (ViR) for failed surgical repairs, and valve-in-mitral annular calcifications (ViMAC) for mitral valvular disease with severe mitral annular calcifications and poor surgical criteria. The FDA approved Mitral ViV for patients with a high surgical risk in 2017, while ViR and ViMAC are still currently under consideration. The SAPIEN M3 valve is relatively new with a trans-septal system, with a success rate of 86%, and no mortality in a 30-day outcome. The Cardiovalve is a bovine pericardium device that has a dual nitinol frame with a custom surgical design to facilitate TMVR. The AHEAD trial will evaluate whether the device is safe to use in a clinical setting and how effective it is for reducing MR in these patients. The trial consists of 30 patients in which the first 5 patients showed 100% technical success and a reduction of MR. This evolution of modern medicine has assisted in many different countries, including Pakistan where there is a higher prevalence of MR and hence, a greater need to apply TMVR in clinical practice.

Intraoperative transesophageal echocardiography following mitral valve repair: a systematic review

OBJECTIVE

We aimed to examine the recent evidence and search for novel assessments on intraoperative TEE following mitral valve repair that can impact short and long-term outcomes.

METHODS

The Ovid MEDLINE, PubMed, and EMBASE databases were searched from January 1, 2008, until January 27, 2021, for studies on patients with severe Mitral Valve Regurgitation (MR) undergoing Mitral Valve (MV) repair surgery with intraoperative Transesophageal Echocardiography (TEE) performed after the repair. Additional searches were conducted using Google search engine, Web of Science, and Cochrane Library.

RESULTS

After reviewing 302 records, 8 retrospective and 22 prospective studies were included (n = 30). Due to clinical and methodological diversity, these studies are noncomparable and data were not amenable to quantitative synthesis.

CONCLUSION

Although technological advances allowed the objective assessment of geometric and dynamic alterations of the MV, the impact of the use of these technologies on short- or long-term outcomes was not studied. There is uncertainty and conflicting evidence on the ideal method and metrics to evaluate MV patency post-repair. Few isolated studies validated methods to assess coaptation surface and LV function post-repair.

Echocardiographic Evaluation of Successful Mitral Valve Repair or Need for a Second Pump Run in the Operating Room

Detailed preoperative and intraoperative echocardiographic assessment of the mitral valve apparatus is critical for a successful repair. The recent advent of 3-dimensional transesophageal echocardiography has added an extra pivotal role to transesophageal echocardiography in the assessment of mitral apparatus and mitral regurgitation. Because surgeons must rapidly decide whether cardiopulmonary bypass should be continued to be weaned off or a second pump run should be selected, the echocardiographer conducting intraoperative transesophageal echocardiography is required to be trained according to a certain algorithm. This review summarizes the current clinical role of intraoperative transesophageal echocardiography in mitral valve repair in the operating room.

One Hundred Percent Reparability of Mitral Prolapse: Results of a Dynamic Nonresectional Technique

BACKGROUND

We studied the results of a dynamic mitral repair technique that preserves normal mitral valve function by avoiding leaflet resection and rigid and semirigid annuloplasty rings.

METHODS

In previous reports we demonstrated that intraoperative simulation of mitral valve locking and isovolumic systole by rapid left ventricular inflation with pressurized saline accurately simulates mitral annular and leaflet shape and position, and left ventricular outflow tract dimensions. Length of polytetrafluoroethylene neochordae and size of fully flexible adjustable annuloplasty ring can be adjusted in three dimensions for accurate apposition of zones of leaflet coaptation, premarked with dots. We followed 1068 consecutive patients after repairs performed between 2001 and 2018.

RESULTS

Of the 1068 patients, 674 were men (63.1%). Mean age was 62.25 ± 13 years. Leaflet repaired was anterior in 118 patients (11.05%), posterior in 564 (52.81%), both in 55 (5.15%), and neither in 123 (11.5%). Barlow's disease was present in 208 patients (19.48%). Repair was isolated in 82.5% (881 of 1068). Reparability was 100%. Perioperative mortality overall was 1.59% (17 of 1068): isolated repair, 1.14% (10 of 881); and isolated posterior leaflet, 0.85% (4 of 472). Leaflet systolic anterior motion occurred in 1.7% (18 of 1068), and was significant in 0.4% (4 of 1068). Survival at 10 years by Kaplan-Meier analysis was 74.65%, freedom from reoperation was 96.01%, and freedom from severe mitral regurgitation was 94%. The only predictor of reoperation (Cox analysis) was being male (P = .001).

CONCLUSIONS

Use of intraoperative simulation of mitral dynamics led to 100% reparability for degenerative valves with minimal systolic anterior motion, despite no leaflet resection. Long-term durability has been good and similar for all leaflets.

Surgical treatment of mitral regurgitation

PURPOSE OF REVIEW

Mitral repair is the best treatment for degenerative mitral regurgitation. Many patients are referred too late for optimal outcomes. The US repair vs. replacement rate is only 60-80%, at a time when the inferiority of replacement has been established. Therefore, widely used traditional techniques of repair are being reappraised.

RECENT FINDINGS

Identification of risk factors predictive of poor early and late outcome have improved timing for surgical referral. Composite risk scores have been developed. Novel echocardiographic, cardiac MRI, and molecular level risk factors could improve timing. Analysis of factors contributing to low repair rates is also of critical importance. The role of institutional and surgeon volumes have been identified. More detailed data on the importance of dynamic function of the mitral valve have led to improved repair techniques such as intraoperative simulation of end diastole and early systole, use of expanded polytetrafluoroethylene neochords instead of leaflet resection, and dynamic instead of rigid annuloplasty.

SUMMARY

Our perception of mitral regurgitation has changed from a seemingly simple condition to one of considerable complexity at multiple levels. National guidelines should be studied and followed.

3-Dimensional Echocardiography: Latest Developments and Future Directions

The ongoing refinements in 3-dimensional (3D) echocardiography technology continue to expand the scope of this imaging modality in clinical cardiology by offering new features that stem from the ability to image the heart in its complete dimensionality. Over the years, countless publications have described these benefits and tested new frontiers where 3D echocardiographic imaging seemed to offer promising ways to improve patients' care. These include improved techniques for chamber quantification and novel ways to visualize cardiac valves, including 3D printing, virtual reality, and holography. The aims of this review article are to focus on the most important developments in the field in the recent years, discuss the current utility of 3D echocardiography, and highlight several interesting future directions.

Recent advances in understanding and managing mitral valve disease

Interest in the mitral valve has increased over the past few years with the development of new technologies that allow intervention in patients previously deemed too ill for treatment. This increased attention has resulted in a significant increase in publications on the mitral valve, the majority of which focus on mitral regurgitation and mitral valve surgery/intervention. The focus of this review is on publications in the past few years that offer additional insights into our understanding and management of mitral valve disease and specifically mitral regurgitation. It will discuss mitral valve anatomy, epidemiology of mitral valve disease, changes in the 2017 management guidelines, management of mitral bioprosthetic valves, transcatheter mitral valve procedures and the repair of rheumatic valves.

Mid-term outcomes of simultaneous mitral valve repair in patients with miral regurgitation and concomitant annulo-aortic ectasia

OBJECTIVE

This study investigated the mid-term outcomes of simultaneous mitral valve repair in patients with mitral regurgitation (MR) and concomitant annulo-aortic ectasia.

METHODS

The study included 26 patients with MR and annulo-aortic ectasia [mean age 46.0 ± 19.9 (10-86) years] who underwent simultaneous mitral valve repair between January 2007 and March 2018. Of these 26 patients, 11 (42.3%) were diagnosed with Marfan syndrome and 10 (38.5%) with Barlow's disease. All patients underwent complete ring annuloplasty; a semi-rigid ring was used in 14 (53.8%) and a semi-flexible ring (anterior-flexible) in 12 patients (46.2%). All patients underwent valve-sparing root replacement using the reimplantation technique.

RESULTS

The overall 3-year survival rate was 95.7 ± 4.3%. The 3-year freedom from > moderate MR rate was 94.7 ± 5.1%, and the 3-year freedom from > moderate aortic regurgitation (AR) rate was 86.7 ± 7.3%. The 3-year freedom from reoperation rate was 100%. The 3-year freedom from > moderate MR rate was 100% in the semi-rigid ring group and 85.7 ± 13.2% in the semi-flexible ring group (log-rank test, p = 0.5371). The 3-year freedom from > moderate AR rate was 100% in the semi-rigid ring group and 72.9 ± 16.5% in the semi-flexible ring group (log-rank test, p = 0.0815).

CONCLUSIONS

Simultaneous mitral valve repair in patients with MR and concomitant annulo-aortic ectasia showed favorable mid-term outcomes.

Impact of different annuloplasty rings on geometry of the mitral annulus with fibroelastic deficiency: the significance of aorto-mitral angle

We sought to investigate the impact of full annuloplasty rings versus C-shape bands on mitral annular geometry in the presence of fibroelastic deficiency (FED), as assessed by intraoperative three-dimensional transesophageal echocardiography (3DTEE). We retrospectively selected 65 patients who underwent mitral valve repair for severe mitral regurgitation caused by FED using full rings (the Ring group, n = 30) and C-shape bands (the Band group, n = 35). 71 controls without valvular heart disease were also included. Thorough 3DTEE inspections were performed for the entire cohort to measure morphological parameters of mitral annulus before and after surgery. Mid-term repair durability and left atrial diameter were followed up. The preoperative 3DTEE parameters, including annular diameters, area, height and aorto-mitral angle, were significantly larger in the FED groups than normal, and were comparable between two groups using different annuloplasty devices. After repair, the anterior-posterior diameter, annulus circumference and area were significantly larger in the Band group than in the Ring group. The aorto-mitral angle became comparable with normal value in the Ring group (p = 0.728), but not in the Band group (p = 0.011). Follow-up echocardiographic data showed a significant correlation between postoperative aorto-mitral angle and reduced left atrial diameter at 50.3 months after surgery (r = 0.63; p < 0.001). In conclusion, compared with C-shape bands, full rings may impose less narrowing on aorto-mitral angle, which correlates well with mid-term left atrial reverse remodeling.

Current indications for stentless aortic bioprostheses

The best aortic prostheses have been debated for decades. The introduction of stentless aortic bioprostheses was aimed at improving hemodynamics and potentially the durability of aortic bioprostheses. Despite the good short- and long-term outcomes after implantation of stentless aortic bioprostheses, their use remains limited owing to the technically demanding implantation techniques. Nevertheless, stentless aortic bioprostheses might be of special benefit in certain indications, where they could be a valuable addition to the surgical armamentarium.

Semi-automated segmentation and quantification of mitral annulus and leaflets from transesophageal 3-D echocardiographic images

Quantification of three-dimensional (3-D) morphology of the mitral valve (MV) using real-time 3-D transesophageal echocardiography (RT3-D TEE) has proved to be a valuable tool for the assessment of MV pathologies, but of limited use in clinical practice because it relies on user-intensive approaches. This study presents a new algorithm for the segmentation and morphologic quantification of the mitral annulus (MA) and mitral leaflets (ML) in closed valve configuration from RT3-D TEE volumes. Following initialization, the MA and the ML and the coaptation line (CL) are automatically obtained in 3-D. Validation with manual tracings was performed on 33 patients, resulting in segmentation errors in the order of 0.7 mm and 0.6 mm for the MA and ML segmentation, in addition to good intra- and inter-observer reproducibility (coefficients of variation below 12% and 15%, respectively). The ability of the algorithm to assess different MV pathologies as well as repaired valves with implanted annular rings was also explored. The reported performance of the proposed fast, semi-automated MA and ML quantification makes it promising for future applications in clinical settings such as the operating room, where obtaining results in short time is important.

Three-dimensional transesophageal echocardiographic study of aortic-mitral valve coupling after coronary artery bypass grafting

AIMS

To observe the geometric changes in aortic-mitral valve coupling (AMC) on three-dimensional transesophageal echocardiography and the factors leading to decreased mitral regurgitation (MR) after coronary artery bypass grafting (CABG).

METHODS AND RESULTS

This study included 23 patients undergoing CABG for coronary artery disease. Fifteen patients with moderate to severe MR were separately analyzed to determine whether the severity of MR influences the geometric change in AMC. Echocardiographic examinations were performed pre- and post-CABG, and the studied parameters were obtained using Siemens Auto Valve Analysis software. The effective mitral regurgitant orifice area, left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), and end-systolic volume (ESV) were measured pre- and post-CABG using Philips QLAB software. Ischemic MR, EDV, and ESV significantly decreased (all P < 0.05) and LVEF significantly improved (P < 0.05) after CABG. There were no significant differences between the pre- and post-CABG mitral valve (MV) parameters, aortic valve parameters, aortic-mitral annular angle, or centroid distance (all P > 0.05). Patients with moderate to severe MR exhibited the same results.

CONCLUSION

The results of this study show that CABG does not cause an acute change in the geometry of AMC. Improved left ventricular function might increase the closing force of the MV, leading to decreased MR after CABG alone. MR significantly improved after CABG alone without MV treatment in the present study. This result may help to guide surgeons in choosing the optimal surgical methods for individual patients.

Incremental value of 3-D transesophageal echocardiographic imaging of the mitral valve

Transesophageal echocardiography provides excellent visualization of the posteriorly located mitral valve. Over the last decade, 3-dimensional transesophageal echocardiography (3D TEE) has emerged as an exciting imaging modality, particularly of the mitral valve. The current generation matrix array technology allows the operator to perform 2D and 3D imaging with a single transducer. 3D TEE affords the unique ability to view the mitral valve and its surrounding structures "en face" in real time (RT), and provide contextual anatomical guidance during surgical and transcatheter interventions. Additionally, offline quantification has made significant contributions to our mechanistic understanding of the normal and diseased mitral valve, and alterations induced by therapeutic intervention such as surgical repair. This review will address recent advances in the incremental role of 3D TEE in mitral valve imaging.

Assessment of aortic and mitral annuli dynamics during the cardiac cycle using speckle tracking echocardiography

The aims of this study were i) to evaluate mitral and aortic annuli excursion, and aortomitral angle (AMA) during the cardiac cycle in healthy adults using two-dimensional speckle tracking echocardiography, ii) to assess two annuli dynamics and coupling behaviors as an integral, and iii) to detect the relation between two annuli and left ventricular ejection fraction (LVEF). A total of 74 healthy adults underwent transthoracic echocardiography. In the parasternal long-axis view, a number of points were extracted, including right coronary aortic annular, aortomitral fibrous junction, and posterior mitral annular points. The annuli excursion and AMA were measured using a speckle tracking-derived software during the cardiac cycle. During the isovolumic contraction and the isovolumic relaxation phase, annuli excursion and AMA remain stable for a short time. During the systole, annuli excursion increased sharply to the maximum, while AMA narrowed quickly to the minimum value. During the diastole, there are three patterns of decrease in annuli excursion and AMA expansion in different phases. The annuli excursion of three points correlates well with the LVEF (right coronary aortic annulus excursion, r=0.71, P<0.05; non-coronary aortic annulus excursion, r=0.70, P<0.05; posterior mitral annulus excursion, r=0.82, P<0.05). Moreover, there are positive correlations between annuli excursion and the variation of AMA (r=0.60, P<0.05). The annuli excursion and AMA have various regular patterns in healthy adults. The interactions of mitral and aortic annuli correlate with the left ventricular function. Our findings may have relevance to the evaluation of left ventricular function and presurgical planning of patients with valvular diseases.

Three-Dimensional Echocardiography: Advancements in Qualitative and Quantitative Analyses of Mitral Valve Morphology in Mitral Valve Prolapse

Degenerative mitral valve disease (MVD) is the leading cause of organic mitral regurgitation (MR), one of the most common valvular heart disease in western countries. Substantial progresses in the surgical treatment of degenerative MVD have improved life expectancy of patients with significant MR. However, prognosis, surgical decision and timing of surgery strongly depend on the accurate characterization of mitral valve (MV) anatomy and pathology and on the precise quantification of MR. Three-dimensional (3D) echocardiography, a major technological breakthrough in the field of cardiovascular imaging, provides several advantages over two-dimensional (2D) imaging in the qualitative and quantitative evaluations of MV apparatus. In this review, we focus on the contribution of this new modality to the diagnosis of degenerative MVD, the quantitative assessment of MR severity, the selection and monitoring of surgical and percutaneous procedures, the evaluation of procedural outcomes. The results of a systematic and exhaustive search of the existing literature, restricted to real-time 3D echocardiography in adults, are here reported.

Three-dimensional echocardiography of the mitral valve: lessons learned

Three-dimensional echocardiography has markedly improved our understanding of normal and pathologic mitral valve (MV) mechanics. Qualitative and quantitative analysis of three-dimensional (3D) data on the mitral valve could have a clinical impact on diagnosis, patient referral, surgical strategies, annuloplasty ring design and evaluation of the immediate and long-term surgical outcome. This review covers the contribution of 3D echocardiography in the diagnosis of MV disease, its role in selecting and monitoring surgical procedures, and in the assessment of surgical outcomes. Moreover, advantages of this technique versus the standard 2D modality, as well as future applications of advanced analysis techniques, will be reviewed.

A three-dimensional echocardiographic study on aortic-mitral coupling in transcatheter aortic valve replacement

AIMS

Normal aortic valve (AV) and mitral valve (MV) function in a reciprocal interdependent fashion. We hypothesized that MV function would be affected by severe aortic stenosis (AS) and that it would remain altered after transcatheter AV replacement (TAVR). Using three-dimensional (3D) echocardiography, we studied aortic-mitral coupling in patients with severe AS undergoing TAVR and compared them with controls.

METHODS AND RESULTS

Three-dimensional transoesophageal echocardiography (Philips iE33) was performed on 43 patients: 27 with severe AS studied pre- and post-TAVR and 16 controls. A custom software tracked the aortic annulus (AoA) and mitral annulus (MA), allowing dynamic automated measurements of AoA and MA morphology, angle, and motion. The AS pre-TAVR patients had significantly reduced MA displacement, MA area, and maximum AoA area compared with the controls. Post-TAVR, MA displacement, MA area, and AoA area remained reduced. End-systolic AoA-MA angle was significantly wider in the AS patients compared with the controls and remained wider post-TAVR. Pre-TAVR, there was no difference in MA or AoA dynamics between patients with mild vs. moderate-to-severe MA calcium; Edwards-Sapien vs. a Medtronic CoreValve valve; normal vs. reduced left ventricular systolic function whereas post-TAVR, MA dynamics were significantly reduced in those with moderate-to-severe MA calcium.

CONCLUSION

This is the first study to demonstrate that AS can affect a secondary 'unaffected' valve, the MV, due to the calcification in the aortic-mitral fibrous continuity. TAVR does not result in recovery of MV structure. These changes have implications in the future TAVR valve development and the possible need for MV assessment pre- and post-TAVR.