2020 Focused Update of the 2017 ACC Expert Consensus Decision Pathway on the Management of Mitral Regurgitation

Superiority of 3D planimetry over pressure half-time method for the assessment of mitral valve area after percutaneous edge-to-edge mitral repair

INTRODUCTION AND OBJECTIVES

There is limited evidence to identify the most accurate method for measuring the mitral valve area (MVA) after percutaneous edge-to-edge mitral repair. Our objective was to evaluate the optimal method in this context and its correlation with the mean transmitral gradient.

METHODS

A registry of patients undergoing percutaneous mitral repair was conducted, analyzing different methods of measuring MVA and their correlation with the mean gradient.

RESULTS

We analyzed data from 167 patients. The mean age was 76±10.3 years, 54% were men, and 46% were women. Etiology was degenerative in 45%, functional in 39%, and mixed in 16%. Postclip MVA measurements were 1.89±0.60 cm2 using pressure half-time (PHT), 2.87±0.83 cm2 using 3D planimetry, and the mean gradient was 3±1.19mmHg. MVA using 3D planimetry showed a stronger correlation with the mean gradient (r=0.46, P<.001) than MVA obtained by PHT (r=0.19, P=.048). Interobserver agreement was also higher with 3D planimetry than with PHT (intraclass correlation coefficient of 0.90 vs 0.81 and variation coefficient of 9.6 vs 19.7%, respectively).

CONCLUSIONS

Our study demonstrates that the PHT method significantly underestimates MVA after clip implantation compared with direct measurement using transesophageal 3D planimetry. The latter method also correlates better with postimplantation gradients and has less interobserver variability. These results suggest that 3D planimetry is a more appropriate method for assessing postclip mitral stenosis.

2024 CSANZ Position Statement on Indications, Assessment and Monitoring of Structural and Valvular Heart Disease With Transthoracic Echocardiography in Adults

Transthoracic echocardiography (TTE) is the most widely available and utilised imaging modality for the screening, diagnosis, and serial monitoring of all abnormalities related to cardiac structure or function. The primary objectives of this document are to provide (1) a guiding framework for treating clinicians of the acceptable indications for the initial and serial TTE assessments of the commonly encountered cardiovascular conditions in adults, and (2) the minimum required standard for TTE examinations and reporting for imaging service providers. The main areas covered within this Position Statement pertain to the TTE assessment of the left and right ventricles, valvular heart diseases, pericardial diseases, aortic diseases, infective endocarditis, cardiac masses, pulmonary hypertension, and cardiovascular diseases associated with cancer treatments or cardio-oncology. Facilitating the optimal use and performance of high quality TTEs will prevent the over or under-utilisation of this resource and unnecessary downstream testing due to suboptimal or incomplete studies.

The Evolving Concept of Secondary Mitral Regurgitation Phenotypes: Lessons From the M-TEER Trials

Conflicting results from 2 randomized clinical trials of transcatheter mitral valve edge-to-edge repair in secondary mitral regurgitation (SMR) have led to the recognition that SMR is a heterogeneous disease entity presenting with different functional and morphological phenotypes. This review summarizes the current knowledge on SMR caused primarily by atrial secondary mitral regurgitation (aSMR) and ventricular SMR pathology. Although aSMR is generally characterized by severe left atrial enlargement in the setting of preserved left ventricular anatomy and function, different patterns of mitral annular distortion cause different phenotypes of aSMR. In ventricular SMR, the relation of SMR severity to left ventricular dilation as well as the degree of pulmonary hypertension and right ventricular dysfunction are important phenotypic characteristics, which are key for a better understanding of prognosis and treatment response.

Outcomes of Transcatheter Mitral Valve Repair Using the MitraClip System in Patients With Atrial Fibrillation. A Meta-Analysis

Transcatheter mitral valve repair (TMVR) with the MitraClip system is now approved for degenerative and functional mitral regurgitation (MR). Atrial fibrillation (AF) is commonly seen in MR. In our study, we perform a pooled analysis of the existing data to investigate the outcomes of MitraClip in patients with versus without AF. We conducted a systematic search of PubMed, Google Scholar, and SCOPUS databases through December, 2022 for studies comparing the outcomes of TMVR using the MitraClip in patients with preexisting AF versus those without AF. A meta-analysis was performed to investigate the primary outcomes of all-cause mortality and heart failure (HF) hospitalization. Secondary outcomes were cardiovascular mortality, in-hospital mortality, stroke, New York Heart Association class I or II at follow-up, length of hospital stay, and procedural time. A total of 10 studies (n = 24,111; AF = 12,789; no AF = 11,322) were included in the final analysis. Preexisting AF was associated with higher overall all-cause mortality (odds ratio 1.55, 95% confidence interval 1.32 to 1.83, p <0.0002) and higher overall HF hospitalization rate (odds ratio 1.3, 95% confidence interval 1.08 to 1.56, p <0.0154). There was no statistically significant difference in cardiovascular mortality, in-hospital mortality, stroke, length of hospital stay, procedural time, or New York Heart Association class I/II at follow-up comparing AF versus no AF. The presence of AF in patients who underwent TMVR with MitraClip is associated with higher all-cause mortality and HF hospitalization. This should be taken into consideration in the management of MR patients.

Mitral Valve Interventions for Hypertrophic Obstructive Cardiomyopathy

The mitral valve (MV) plays an important role in the pathophysiology of hypertrophic obstructive cardiomyopathy (HOCM). Dynamic left ventricular outflow tract (LVOT) obstruction, caused by systolic anterior motion (SAM), is a common occurrence in most patients with hypertrophic cardiomyopathy and is directly associated with the MV apparatus. First line therapy for HOCM patients is pharmacological, and surgical intervention is often indicated for patients who do not respond to medical therapy. Emerging research on mitral disease in HOCM, specifically mitral regurgitation (MR), demonstrates that these patients frequently do not respond to standard therapeutic options, and can benefit from MV interventions. In this review, we describe the involvement of the MV in the pathogenesis of HOCM, discuss medical therapy, and explore available mitral procedures. Surgical myectomy, often combined with various modifications to the MV apparatus, is frequently necessary to achieve a durable resolution of LVOT obstruction and SAM-related MR. Alcohol septal ablation, an alternative to surgical myectomy, will be briefly mentioned. We also emphasize the role of transcatheter edge-to-edge repair (TEER) as a promising and novel therapeutic option for HOCM patients. Over time, TEER has established itself as an effective and safe procedure, demonstrating success across a spectrum of anatomical variations. The leaflet modification and movement restriction achieved through TEER help reduce SAM and, consequently, have the potential to alleviate LVOT obstruction and SAM-related MR. Furthermore, we propose a treatment algorithm for cases where TEER is a potential course of action for patients who are at high risk for other interventions.

Mitral regurgitation in heart failure with preserved ejection fraction: The interplay of valve, ventricle, and atrium

Mitral regurgitation (MR) is highly prevalent among patients with heart failure and preserved ejection fraction (HFpEF). Despite this combination being closely associated with unfavourable outcomes, it remains relatively understudied. This is partly due to the inherent heterogeneity of patients with HFpEF. To address this gap, dissecting HFpEF into mechanism-based phenotypes may offer a promising avenue for advancing our comprehension of these complex intertwined conditions. This review employs the validated CircAdapt model to explore the haemodynamic implications of moderate to severe MR across a well-defined spectrum of myocardial disease, characterized by impaired relaxation and reduced myocardial compliance. Both heart failure and mitral valve disease share overlapping symptomatology, primarily attributed to elevated pulmonary pressures. The intricate mechanisms contributing to these elevated pressures are multifaceted, potentially influenced by diastolic dysfunction, left atrial myopathy, and MR. Accurate evaluation of the haemodynamic and clinical impact of MR necessitates a comprehensive approach, taking into account the characteristics of both the left atrium and left ventricle, as well as their intricate interactions, which may currently be underemphasized in diagnostic practice. This holistic assessment is imperative for enhancing our understanding and refining therapeutic strategies within this patient cohort.

Long-Term Impact of Small Mitral Valve Orifice Area after Transcatheter Edge-to-Edge Mitral Valve Repair on Clinical Outcome: A Three-Dimensional Echocardiography Study

BACKGROUND

Iatrogenic mitral stenosis is a complication associated with transcatheter edge-to-edge mitral valve repair. Some reports revealed the impact of mean transmitral pressure gradient after procedure on long-term clinical outcomes. However, the association between prognosis and mitral valve orifice area (MVA) after the procedure has been poorly studied. This study aimed to investigate the association between postprocedural small MVA, derived from three-dimensional (3D) transesophageal echocardiography (TEE), and long-term clinical outcomes in 2 cohorts: the degenerative mitral regurgitation (MR) cohort and the functional MR cohort.

METHODS

This retrospective study assessed 279 consecutive patients with 3D TEE data during transcatheter edge-to-edge mitral valve repair between January 2010 and December 2016. Mitral valve orifice area after device implantation was measured by 3D planimetry. The patients with degenerative and functional MR were stratified separately into 2 groups according to postprocedural MVA: normal MVA (MVA > 1.5 cm2) group and small MVA (MVA ≤ 1.5 cm2) group.

RESULTS

Of the 279 patients, 142 (51%) had degenerative MR and 137 (49%) had functional MR. The number of degenerative MR patients with small MVA was 38, whereas 42 patients were in the functional MR cohort. Patients with small MVA had higher rate of all-cause mortality in the degenerative MR group (log-rank test: P = .01) but not in the functional MR group (log-rank test: P = .52). In multivariate analysis small MVA was independently associated with all-cause mortality but not postprocedural transmitral pressure gradient. Neither small MVA nor transmitral pressure gradient was associated with all-cause mortality in patients with functional MR.

CONCLUSION

Small MVA measured by 3D TEE after transcatheter mitral edge-to-edge repair was associated with poor prognosis in patients with degenerative MR.

Robotic degenerative mitral repair: Factors associated with intraoperative revision and impact of mild residual regurgitation

OBJECTIVES

National registry data show wide variability in degenerative mitral repair rates and infrequent use of intraoperative repair revision to eliminate residual mitral regurgitation (MR). The consequence of uncorrected mild residual MR is also not clear. We identified factors associated with intraoperative revision of degenerative mitral repair and evaluated long-term effects of intraoperative mild residual MR.

METHODS

A prospective institutional registry of 858 patients with degenerative MR undergoing robotic mitral surgery was linked to statewide databases. Univariate logistic regression identified factors associated with intraoperative repair revision. Survival was estimated using the Kaplan-Meier method and adjusted with Cox regression. Late freedom from more-than-moderate MR or reintervention was estimated with death as a competing risk.

RESULTS

Repair rate was 99.3%. Repair was revised intraoperatively in 19 patients and was associated with anterior or bileaflet prolapse, adjunctive repair techniques, and annuloplasty band size (all P < .05). Intraoperative repair revision did not result in increased postoperative complications. Intraoperative mild residual MR (n = 111) was independently associated with inferior 8-year survival (hazard ratio, 2.97; 95% CI, 1.33-6.23), worse freedom from more than moderate MR (hazard ratio, 3.35; 95% CI, 1.60-7.00), and worse freedom from mitral reintervention (hazard ratio, 6.40; 95% CI, 2.19-18.72) (all P < .01).

CONCLUSIONS

A near 100% repair rate with acceptable durability may be achieved safely with intraoperative revision of postrepair residual MR. Mild residual MR was independently associated with reduced survival, worse freedom from more-than-moderate MR, and worse freedom from mitral reintervention at 8-year follow-up.

Expert proposal to analyze the combination of aortic and mitral regurgitation in multiple valvular heart disease by comprehensive echocardiography

The assessment of valvular pathologies in multiple valvular heart disease by echocardiography remains challenging. Data on echocardiographic assessment-especially in patients with combined aortic and mitral regurgitation-are rare in the literature. The proposed integrative approach using semi-quantitative parameters to grade the severity of regurgitation often yields inconsistent findings and results in misinterpretation. Therefore, this proposal aims to focus on a practical systematic echocardiographic analysis to understand the pathophysiology and hemodynamics in patients with combined aortic and mitral regurgitation. The quantitative approach of grading the regurgitant severity of each compound might be helpful in elucidating the scenario in combined aortic and mitral regurgitation. To this end, both the individual regurgitant fraction of each valve and the total regurgitant fraction of both valves must be determined. This work also outlines the methodological issues and limitations of the quantitative approach by echocardiography. Finally, we present a proposal that enables verifiable assessment of regurgitant fractions. The overall interpretation of echocardiographic results includes the symptomatology of patients with combined aortic and mitral regurgitation and the individual treatment options with respect to their individual risk. In summary, a reproducible, verifiable, and transparent in-depth echocardiographic investigation might ensure consistent hemodynamic plausibility of the quantitative results in patients with combined aortic and mitral regurgitation.

Impact of coronary artery disease on outcome after transcatheter edge-to-edge mitral valve repair with the MitraClip system

BACKGROUND

The clinical impact of coronary artery disease (CAD) on the prognosis of patients undergoing MitraClip implantation is still unclear.

METHODS

One thousand nine hundred fifty-three patients undergoing MitraClip implantation included in the multicenter GIOTTO Registry were stratified according to CAD. Endpoints were all-cause death, cardiac death, and re-hospitalization for heart failure at follow-up (median 15.8 months).

RESULTS

Although younger, CAD patients were more symptomatic, had worse cardiovascular risk profile, higher burden of comorbidities, more frequently affected by functional MR, with higher left ventricle (LV) diameters and lower ejection fraction (EF). At follow-up, CAD patients showed higher rates of all-cause death (25.4% vs. 19.6%; P=0.002), cardiovascular death (14.0% vs. 10.1%; P=0.007) and re-hospitalization for heart failure (13.9% vs. 10.2%; P=0.011). Dividing the population according to mitral regurgitation (MR) etiology (functional vs. non-functional MR), no differences were observed between CAD and no-CAD patients. At multivariate logistic regression, NYHA III/IV class, prior heart failure hospitalization, severe chronic kidney disease, atrial fibrillation, LV end-diastolic diameter and LVEF<30% but not CAD resulted independent predictors of all-cause death. The same finding was confirmed even after propensity score adjustment.

CONCLUSIONS

CAD did not show a relevant impact on mid-term prognosis per se, but seemed to identify a more complex and diseased cohort of patients with worse clinical and functional status.

Multidetector Computed Tomography in Patients Who Underwent Transcatheter Mitral Edge-to-Edge Repair

Multidetector computed tomography (MDCT) can provide valuable information for mitral assessment, but its role in transcatheter mitral edge-to-edge repair (TEER) planning has been poorly elucidated. We aimed to compare MDCT with 3-dimensional transesophageal echocardiography (3D-TEE) for TEER preprocedural evaluation. We analyzed the preprocedural MDCT and 3D-TEE of 108 consecutive patients with mitral regurgitation (MR) who underwent MitraClip implantation. The levels of agreement for the etiology and mechanism of MR, mitral calcification, mitral annulus, and mitral valve orifice area (MVOA) measurements were compared between MDCT and 3D-TEE data. Receiver-operating-characteristic curves were generated for mitral annulus area and MVOA using a low mean transmitral pressure gradient at discharge (<5 mm Hg) as the state variable, and the primary outcome of all-cause mortality or rehospitalization for heart failure at 1 year was compared between MDCT's and 3D-TEE's MVOA <4-cm2 cutoff. Good levels of agreement between MDCT and 3D-TEE were observed for determining the etiology (κ = 0.81) and mechanism (κ = 0.62) of MR but not for grading mitral calcification (κ = 0.31 to 0.35). The correlations between MDCT and 3D-TEE measurements were strong for mitral annulus area (r = 0.90) and good for MVOA (r = 0.73). Furthermore, no significant differences in the area under the receiver-operating-characteristic curve to predict low transmitral pressure gradient at discharge or the primary outcome at 1 year were detected between MDCT- and 3D-TEE-derived parameters (all p >0.05). In conclusion, in patients who underwent TEER with MitraClip, a high degree of agreement for comprehensive evaluation of MR and prediction of clinical outcomes between MDCT and 3D-TEE was observed.

Left ventricular reverse remodeling after transcatheter aortic valve replacement for predominant aortic stenosis and mixed aortic valve disease

BACKGROUND

Mixed aortic valve disease (MAVD) is a frequent concomitant valve disease with unique cardiac pathological changes compared to predominant aortic stenosis (PAS). The previous studies about the MAVD are contradictory. Therefore, a new perspective is needed to assess the value of TAVR for this cohort of patients.

METHODS

From January 2018 to December 2021, 90 MAVD patients and 72 PAS patients who underwent TAVR in our hospital were collected. 1:1 propensity score matching analysis was used to control the bias in patient selection. The dynamic changes in left ventricular morphology and hemodynamics were compared by generalized estimating equations. Univariate or multivariate logistic regression analysis was used to screen for independent risk factors for the non-occurrence of left ventricular reverse remodeling (non-LVRR).

RESULTS

After the matching procedure, 112 patients were included in the analysis (56 in each group). Baseline characteristics were similar between the two groups. LVRR occurred in both groups, but MAVD had greater left ventricular end-diastolic volume index and left ventricular mass index, a higher incidence of mitral regurgitation (MR), and a more pronounced transformation of ventricular geometry patterns. Post-operative MR (odd ratio [OR]: 10.05; 95% confidence interval [CI]: 2.08-48.57; p < .001) and coronary artery disease (OR: 2.82; 95% CI: 1.08-7.34; p = .034) were independent risk factors for non-LVRR.

CONCLUSION

LVRR also occurs in patients with MAVD, post-operative MR and coronary artery disease were independent risk factors for non-LVRR.

Progression of Non-Significant Mitral and Tricuspid Regurgitation after Surgical Aortic Valve Replacement for Aortic Regurgitation

Little is known about the natural history of non-significant mitral and tricuspid regurgitation (MR and TR) following surgical aortic valve replacement (SAVR) for aortic regurgitation (AR). We retrospectively analyzed 184 patients (median age 64 (IQR, 55-74) years, 76.6% males) who underwent SAVR for AR. Subjects with significant non-aortic valvulopathies, prior/concomitant valvular interventions, or congenital heart disease were excluded. The cohort was evaluated for MR/TR progression and, based on the latter's occurrence, for echocardiographic and clinical indices of heart failure and mortality. By 5.8 (IQR, 2.8-11.0) years post-intervention, moderate or severe MR occurred in 20 (10.9%) patients, moderate or severe TR in 25 (13.5%), and either of the two in 36 (19.6%). Patients who developed moderate or severe MR/TR displayed greater biventricular disfunction and functional limitation and were less likely to be alive at 7.0 (IQR, 3.4-12.1) years compared to those who did not (47.2 vs. 79.7%, p < 0.001). The emergence of significant MR/TR was associated with preoperative atrial fibrillation/flutter, symptomatic heart failure, and above-mild MR/TR as well as concomitant composite graft use, but not with baseline echocardiographic measures of biventricular function and dimensions, aortic valve morphology, or procedural aspects. In conclusion, among patients undergoing SAVR for AR, significant MR/TR developed in one fifth by six years, correlated with more adverse course, and was anticipated by baseline clinical and echocardiographic variables.

Mitral Interventions in Heart Failure

Patients with heart failure with reduced ejection fraction who have secondary mitral regurgitation (SMR) have poorer outcomes and quality of life than those without SMR. Guideline-directed medical therapy is the cornerstone of SMR treatment. Careful evaluation of landmark trials using mitral transcatheter edge-to-edge repair in SMR has led to an improved understanding of who will benefit from percutaneous interventions with emphasis on a multidisciplinary approach. The success with mitral transcatheter edge-to-edge repair in SMR has also spurred the evaluation of its role in populations that were not initially studied, such as end-stage heart failure and cardiogenic shock. A spectrum of transcatheter devices in development and clinical trials promise to further provide a growing array of management options for heart failure with reduced ejection fraction patients with symptomatic SMR.

Functional Insufficiency of Mitral and Tricuspid Valves Associated With Atrial Fibrillation: Impact of Postoperative Atrial Fibrillation Recurrence on Surgical Outcomes

BACKGROUND AND OBJECTIVES

To identify the factors associated with adverse outcomes following surgery for functional insufficiency of the mitral valve (MV) or tricuspid valve (TV) associated with atrial fibrillation (AF).

METHODS

We evaluated 100 patients (age, 66.5±10.0 years; 47 males) who consecutively underwent surgery for functional insufficiency of the MV or TV associated with AF between January 2000 and December 2020 at our center. The primary outcome was a composite endpoint of all-cause death, valve reoperation, congestive heart failure (CHF) requiring rehospitalization, and stroke.

RESULTS

During follow-up (532 patients-years [PYs]), adverse events included death in 16 (3.0%/yr), MV reoperation in 1 (0.2%/yr), CHF in 14 (2.6%/yr), and stroke in 5 (0.9%/yr) patients, demonstrating a 5-year rate of freedom from the primary endpoint of 69.5%. The rate of postoperative AF was high even in those who underwent AF ablation (n=92), with cumulative rates of 48.1% at 1 year and 60.2% at 5 years. In multivariable analyses, the primary outcome was significantly associated with age (adjusted hazard ratio [aHR], 1.06; 95% confidence interval [CI], 1.02-1.10; p=0.005), chronic kidney disease (aHR, 7.76; 95% CI, 2.28-26.38; p=0.001), left atrial appendage exclusion (aHR, 0.35; 95% CI, 0.16-1.78; p=0.010), and postoperative AF as a time-varying covariate (aHR, 3.33; 95% CI, 1.50-7.40; p=0.003).

CONCLUSION

Among patients undergoing surgery for functional atrioventricular insufficiency associated with AF, a significant proportion showed recurrence of AF over time after concomitant AF ablation, which was significantly associated with poor clinical outcomes.

Expanding the Spectrum of TEER Suitability: Evidence From the EXPAND G4 Post Approval Study

BACKGROUND

Anatomical and clinical criteria to define mitral transcatheter edge-to-edge repair (TEER) "unsuitability" have been proposed on the basis of a Heart Valve Collaboratory consensus opinion from physician experience with early-generation TEER devices but lacked an evidence-based approach.

OBJECTIVES

The aim of this study was to explore the spectrum of TEER suitability using echocardiographic and clinical outcomes from the EXPAND G4 real-world postapproval study.

METHODS

EXPAND G4 is a global, prospective, multicenter, single-arm study that enrolled 1,164 subjects with mitral regurgitation (MR) treated with the MitraClip G4 System. Three groups were defined using the Heart Valve Collaboratory TEER unsuitability criteria: 1) risk of stenosis (RoS); 2) risk of inadequate MR reduction (RoIR); and 3) subjects with baseline moderate or less MR (MMR). A TEER-suitable (TS) group was defined by the absence of these characteristics. Endpoints included independent core laboratory-assessed echocardiographic characteristics, procedural outcomes, MR reduction, NYHA functional class, Kansas City Cardiomyopathy Questionnaire score, and major adverse events through 30 days.

RESULTS

Subjects in the RoS (n = 56), RoIR (n = 54), MMR (n = 326), and TS (n = 303) groups had high 30-day MR reduction rates (≤1+: RoS 97%, MMR 93%, and TS 91%; ≤2+: RoIR 94%). Thirty-day improvements in functional capacity (NYHA functional class I or II at 30 days vs baseline: RoS 94% vs 29%, RoIR 88% vs 30%, MMR 79% vs 26%, and TS 83% vs 33%) and quality of life (change in Kansas City Cardiomyopathy Questionnaire score: RoS +27 ± 26, RoIR +16 ± 26, MMR +19 ± 26, and TS +19 ± 24) were safely achieved in all groups, with low major adverse events (<3%) and all-cause mortality (RoS 1.8%, RoIR 0%, MMR 1.5%, and TS 1.3%).

CONCLUSIONS

Patients previously deemed TEER unsuitable can be safely and effectively treated with the mitral TEER fourth-generation device.

The role and implications of left atrial fibrosis in surgical mitral valve repair as assessed by CMR: the ALIVE study design and rationale

Background

Patients with mitral regurgitation (MR) commonly suffer from left atrial (LA) remodeling. LA fibrosis is considered to be a key player in the LA remodeling process, as observed in atrial fibrillation (AF) patients. Literature on the presence and extent of LA fibrosis in MR patients however, is scarce and its clinical implications remain unknown. Therefore, the ALIVE trial was designed to investigate the presence of LA remodeling including LA fibrosis in MR patients prior to and after mitral valve repair (MVR) surgery.

Methods

The ALIVE trial is a single center, prospective pilot study investigating LA fibrosis in patients suffering from MR in the absence of AF (identifier NCT05345730). In total, 20 participants will undergo a CMR scan including 3D late gadolinium enhancement (LGE) imaging 2 week prior to MVR surgery and at 3 months follow-up. The primary objective of the ALIVE trial is to assess the extent and geometric distribution of LA fibrosis in MR patients and to determine effects of MVR surgery on reversed atrial remodelling.

Implications

This study will provide novel insights into the pathophysiological mechanism of fibrotic and volumetric atrial (reversed) remodeling in MR patients undergoing MVR surgery. Our results may contribute to improved clinical decision making and patient-specific treatment strategies in patients suffering from MR.

Clinical Utility of Three-Dimensional Echocardiography in the Evaluation of Mitral Valve Disease: Tips and Tricks

Although real-time 3D echocardiography (RT3DE) has only been introduced in the last decades, its use still needs to be improved since it is a time-consuming and operator-dependent technique and acquiring a good quality data can be difficult. Moreover, the additive value of this important diagnostic tool still needs to be wholly appreciated in clinical practice. This review aims at explaining how, why, and when performing RT3DE is useful in clinical practice.

Benefit of 3D Vena Contracta Area over 2D-Based Echocardiographic Methods in Quantification of Functional Mitral Valve Regurgitation

BACKGROUND

The two-dimensional proximal isovelocity surface area (2D PISA) method in the quantification of an effective regurgitation orifice area (EROA) has limitations in functional mitral valve regurgitation (FMR), particularly in non-circular coaptation defects.

OBJECTIVE

We aimed to validate a three-dimensional vena contracta area (3D VCA) against a conventional EROA using a 2D PISA method and anatomic regurgitation orifice area (AROA) in patients with FMR.

METHODS

Both 2D and 3D full-volume color Doppler data were acquired during consecutive transoesophageal echocardiography (TEE) examinations. The EROA 2D PISA was calculated as recommended by current guidelines. Multiplanar reconstruction was used for offline analysis of the 3D VCA (with a color Doppler) and AROA (without a color Doppler). Receiver operating characteristic (ROC) analysis was used to calculate a cut-off value for the 3D VCA to discriminate between moderate and severe FMR as classified by the EROA 2D PISA.

RESULTS

From 2015 to 2018, 105 consecutive patients with complete and adequate imaging data were included. The 3D VCA correlated strongly with the 2D PISA EROA and AROA (r = 0.93 and 0.94). In the presence of eccentric or multiple regurgitant jets, there was no significant difference in correlations with the 3D VCA. We found a 3D VCA cut-off of 0.43 cm² to discriminate between moderate and severe FMR (area under curve = 0.98). The 3D VCA showed a higher interobserver agreement than the EROA 2D PISA (interclass correlation coefficient: 0.94 vs. 0.81).

CONCLUSIONS

The 3D VCA has excellent validity and lower variability than the conventional 2D PISA in FMR. Compared to the 2D PISA, the 3D VCA was not affected by the presence of eccentric or multiple regurgitation jets or non-circular regurgitation orifices. With a threshold of 0.43 cm² for the 3D VCA, we demonstrated reliable discrimination between moderate and severe FMR.

Quantification of primary mitral regurgitation by echocardiography: A practical appraisal

The accurate quantification of primary mitral regurgitation (MR) and its consequences on cardiac remodeling is of paramount importance to determine the best timing for surgery in these patients. The recommended echocardiographic grading of primary MR severity relies on an integrated multiparametric approach. It is expected that the large number of echocardiographic parameters collected would offer the possibility to check the measured values regarding their congruence in order to conclude reliably on MR severity. However, the use of multiple parameters to grade MR can result in potential discrepancies between one or more of them. Importantly, many factors beyond MR severity impact the values obtained for these parameters including technical settings, anatomic and hemodynamic considerations, patient's characteristics and echocardiographer' skills. Hence, clinicians involved in valvular diseases should be well aware of the respective strengths and pitfalls of each of MR grading methods by echocardiography. Recent literature highlighted the need for a reappraisal of the severity of primary MR from a hemodynamic perspective. The estimation of MR regurgitation fraction by indirect quantitative methods, whenever possible, should be central when grading the severity of these patients. The assessment of the MR effective regurgitant orifice area by the proximal flow convergence method should be used in a semi-quantitative manner. Furthermore, it is crucial to acknowledge specific clinical situations in MR at risk of misevaluation when grading severity such as late-systolic MR, bi-leaflet prolapse with multiple jets or extensive leak, wall-constrained eccentric jet or in older patients with complex MR mechanism. Finally, it is debatable whether the 4-grades classification of MR severity would be still relevant nowadays, since the indication for mitral valve (MV) surgery is discussed in clinical practice for patients with 3+ and 4+ primary MR based on symptoms, specific markers of adverse outcome and MV repair probability. Primary MR grading should be seen as a continuum integrating both quantification of MR and its consequences, even for patients with presumed “moderate” MR.

Transcatheter edge-to-edge mitral valve repair in mitral regurgitation: current status and future prospects

INTRODUCTION

Mitral regurgitation (MR) is associated with substantial morbidity and mortality. Within the past 15 years, mitral valve edge-to-edge repair (M-TEER) has developed from an experimental approach to a guideline-recommended, safe, and effective treatment option for patients with severe primary or secondary mitral regurgitation.

AREAS COVERED

This review covered relevant publications of M-TEER and summarizes the development of M-TEER devices within the last 15 years. It outlines anatomical challenges which drove the evolution of M-TEER devices, provides an overview about the current state of clinical application and research, and offers an outlook into the future of transcatheter mitral valve treatment.

EXPERT OPINION

The development and refinement of new M-TEER device generations offer the possibility to treat a wide range of mitral valve anatomies. Choosing the best device for the individual anatomic properties of the patients and considering comorbidities is the key to maximized MR reduction, minimalized complication rates, and thus optimized postinterventional prognosis. Independent from prognostic implications, quality of life has become an important patient-centered outcome that can be improved by M-TEER in virtually all patients treated.

Gender-related differences on outcome following transcatheter mitral valve repair (TMVR): a systematic review and meta-analysis

BACKGROUND

The effect of gender on patients with mitral valve regurgitation (MR) undergoing transcatheter mitral valve repair (TMVR) remains to be defined. The aim of the present study is a comprehensive meta-analysis of studies that investigate differences between men and women after TMVR.

METHODS

A systematic literature search was carried out on eight databases to collect all relevant studies on gender-related outcomes of TMVR before March 1, 2021. The main outcomes of interest were mortality, cardiac function, MR class and other complications.

RESULTS

A total of eight literatures were included, all of which were retrospective observational studies. Compared to women patients, men had lower postoperative New York Heart Association (NYHA) class (OR = 1.53, 95%CI [1.23, 1.91], P = 0.0001) and higher incidence of postoperative acute kidney injury (AKI) (OR = 1.25, 95%CI [1.16, 1.34], P < 0.05). There were no significant difference on mortality in 30 days (OR = 0.95, 95%CI [0.81, 1.11], P = 0.53) and in 2 years (OR = 0.99, 95%CI [0.75, 1.30], P = 0.93), mitral valve regurgitation (MR) class (OR = 1.30, 95%CI [0.97, 1.75], P = 0.08) and incidence of myocardial infarction (MI) (OR = 0.88, 95%CI [0.65, 1.18], P = 0.38), stroke (OR = 0.80, 95%CI [0.63, 1.02], P = 0.08) and bleeding in hospital (OR = 0.84, 95%CI [0.59, 1.19], P = 0.32).

CONCLUSIONS

Our meta-analysis demonstrates that men undergoing TMVR have worse preoperative diseases (diabetes mellitus, coronary artery disease, renal failure and myocardial infarction) while they have superior postoperative NYHA class at one-year. There are no significantly difference in other indexes between men and women.

Mitral Valve Transcatheter Edge-to-Edge Repair Using MitraClip or PASCAL: A Multicenter Propensity Score-Matched Comparison

BACKGROUND

Since its introduction in 2003, Abbott's MitraClip (MC) has become the most established catheter-based treatment for mitral regurgitation (MR). Recent approval of Edwards Lifescience's PASCAL device has extended the field of TEER.

OBJECTIVES

The aim of this retrospective multicenter study was to compare the PASCAL and MC regarding procedural results and short- and long-term outcomes after mitral valve transcatheter edge-to-edge repair (TEER).

METHODS

Data from 3 high-volume centers were analyzed. The primary endpoint was residual MR at discharge. Secondary endpoints were technical success, MR reduction, and 30-day mortality. After 1 year, all-cause mortality and residual MR were reported.

RESULTS

A total of 412 patients (216 MC, 196 PASCAL) treated between 2018 and 2020 were included. A total of 184 patients (92 in each treatment group) remained after propensity score matching. The rate of baseline MR ≥3 was 98.9% in both groups (P = 1.00). Both TEER systems achieved equally high technical success rates (97.8%; P = 1.00), resulting in residual MR ≤1 in 69.6% vs 77.1% of patients (P = 0.24) and MR reduction by ≥2 grades in 83.7% vs 92.4% of patients (P = 0.13) using the MC and PASCAL, respectively. Thirty-day mortality was 1.1% in both cohorts (P = 0.98), and 1-year follow-up showed similar MR reductions (residual MR ≤1, 78.0% with MC vs 82.3% with PASCAL; P = 0.70) and comparable all-cause mortality (14.1% with MC vs 6.5% with PASCAL; P = 0.14). In multivariate regression analysis, Society of Thoracic Surgeons score independently correlated with an optimal result (MR ≤1), while device choice did not show a significant impact.

CONCLUSIONS

In this retrospective multicenter study, the established MC and the novel PASCAL mitral valve TEER systems were safe and offered excellent performance with comparable short- and long-term outcomes.

Mitral regurgitation management: a systematic review of clinical practice guidelines and recommendations

Multiple guidelines exist for the diagnosis and management of mitral regurgitation (MR), the second most common valvular heart disease in high-income countries, with recommendations that do not always match. We systematically reviewed guidelines on diagnosis and management of MR, highlighting similarities and differences to guide clinical decision-making. We searched national and international guidelines in MEDLINE and EMBASE (1 June 2010 to 1 September 2021), the Guidelines International Network, National Guideline Clearinghouse, National Library for Health Guidelines Finder, Canadian Medical Association Clinical Practice Guidelines Infobase, and websites of relevant organizations. Two reviewers independently screened the abstracts and identified articles of interest. Guidelines that were rigorously developed (as assessed with the Appraisal of Guidelines for Research and Evaluation II instrument) were retained for analysis. Five guidelines were retained. There was consensus on a multidisciplinary approach from the heart team and for the definition and grading of severe primary MR. There was general agreement on the thresholds for intervention in symptomatic and asymptomatic primary MR; however, discrepancies were present. There was agreement on optimization of medical therapy in severe secondary MR and intervention in patients symptomatic despite optimal medical therapy, but no consensus on the choice of intervention (surgical repair/replacement vs. transcatheter approach). Cut-offs for high-risk intervention in MR, risk stratification of progressive MR, and guidance on mixed valvular disease were sparse.

Usefulness of computed tomography to predict residual mitral regurgitation after transcatheter mitral valve edge-to-edge repair

BACKGROUND

Multidetector computed tomography (MDCT) can provide valuable information for preprocedural planning of transcatheter mitral valve interventions. However, no data exist on MDCT parameters predicting residual mitral regurgitation (MR) post-MitraClip (Abbott Laboratories, Abbott Park, IL, USA).

METHODS

We analyzed preprocedural MDCTs of 78 consecutive patients with secondary MR undergoing MitraClip implantation at our institution. Moderate-or-severe mitral leaflet calcification (MLC) was defined as calcification, with-or-without mitral annular calcification, extending beyond the mitral leaflet base. Residual MR was assessed by postprocedural transesophageal echocardiography, and clinical outcomes were assessed at 1-year.

RESULTS

Fifteen patients (19 %) had residual MR ≥2+. Compared to patients with none-or-mild residual MR, MDCT-derived mitral valve orifice area (MVOA) to mitral annulus area (MAA) ratio was significantly lower (0.32 ± 0.06 vs. 0.39 ± 0.09; p = 0.003), and the prevalence of MLC was higher (40 % vs. 18 %; p = 0.057) in those with residual MR ≥2+. Furthermore, the MVOA/MAA ratio and MLC were independent predictors of residual MR ≥2+ post-MitraClip [adjusted odds ratio (OR_adj): 0.88 (0.80-0.97) and 5.50 (1.16-26.23), respectively]. On receiver-operating-characteristic-curve analysis, MVOA/MAA ratio <0.31 had a sensitivity of 87 % and a specificity of 60 % for residual MR ≥2+. When patients were classified according to the presence of MLC and an MVOA/MAA ratio <0.31, those with both parameters had significantly higher rates of postprocedural residual MR ≥2+ and mitral reintervention at 1-year than those with only one, and those without both parameters.

CONCLUSIONS

In patients with secondary MR undergoing the MitraClip procedure, preprocedural MDCT parameters, specifically MVOA/MAA ratio and MLC, are useful to predict postprocedural residual MR.

Practical Echocardiographic Approach of the Regurgitant Mitral Valve Assessment

Mitral regurgitation is the second-most frequent valvular heart disease in Europe after degenerative aortic stenosis. It is associated with significant morbidity and mortality, and its prevalence is expected to increase with population aging. Echocardiography is the first diagnostic approach to assess its severity, constituting a challenging process in which a multimodality evaluation, integrating quantitative, semiquantitative and qualitative methods, as well as a detailed evaluation of the morphology and function of both left ventricle and atria is the key. In this review, we would like to provide a practical diagnosis approach on the mitral valve regurgitation mechanism, severity quantification, and planning of future therapeutic options.

Dynamics of Cognitive Function in Patients with Heart Failure Following Transcatheter Mitral Valve Repair

Aims: Interventional transcatheter edge-to-edge mitral valve repair (TMVR) is an established treatment option for patients with severe mitral regurgitation (MR) and high operative risk. Cognitive impairment is one of the most common conditions among often extensive comorbidities in these patients. The specific patterns of cognitive decline and particularly the effect of TMVR are not well described. Thus, this study aimed to investigate into the impact of TMVR on cognitive impairment, exercise capacity, and quality of life. Methods: Cognitive function (executive, naming, memory, attention, language, abstraction, and orientation) was assessed with the standardized Montreal Cognitive Assessment test (MoCA; range between 0 and 30 points) before and 3 months after TMVR in 72 consecutive patients alongside echocardiographic examination and assessment of exercise capacity (six-minute walk test) as well as quality-of-life questionnaires (Minnesota living with heart failure questionnaire, MLHF-Q). Results: Patients’ median age was 81 [76.0; 84.5] years, 39.7% were female with a median EuroScore II of 4.4% [2.9; 7.7]. The assessment of cognitive function showed a significant improvement of the cumulative MoCA-Test result (from 22.0 [19.0; 24.5] to 24 [22.0; 26.0]; p < 0.001) with significant changes in the subcategories executive (p < 0.001), attention (p < 0.001), abstraction (p < 0.001), and memory (p < 0.001). In addition, quality of life (from 47.5 [25.0; 69.3] to 24.0 [12.0; 40.0]; p < 0.001) and exercise capacity (from 220.0 m [160.0; 320.0] to 280.0 m [200.0; 380.0]; p = 0.003) increased significantly 3 months after the TMVR procedure. Conclusions: TMVR leads to a significant improvement of cognitive function, exercise capacity, and quality of life in patients with chronic heart failure in 3 months follow up and again highlights the benefit of the evermore established TMVR procedure for patients with high operative risk.

3D Intracardiac Echocardiography in Mitral Transcatheter Edge-to-Edge Repair

Intracardiac echocardiography (ICE) has historically had limited utility in complex structural interventions. Newer 3-dimensional ICE catheters have enhanced imaging and real-time functionality. We present a novel case of mitral valve transcatheter edge-to-edge repair where transesophageal imaging was limited by massive hiatal hernia and where complementary 3D ICE imaging enabled procedural success. (Level of Difficulty: Intermediate.)

Significance of Left Ventricular Ejection Time in Primary Mitral Regurgitation

The optimal timing for mitral valve (MV) surgery in asymptomatic patients with primary mitral regurgitation (MR) remains controversial. We aimed at evaluating the relation between left ventricular ejection time (LVET) and outcome in patients with moderate or severe chronic primary MR because of prolapse. Clinical, Doppler echocardiographic, and outcome data prospectively collected from 302 patients (median age 61 [54 to 74] years, 34% women) with moderate or severe primary MR were analyzed. Patients were retrospectively stratified by quartiles of LVET. The primary end point of the study was the composite of need for MV surgery or all-cause mortality. During a median follow-up time of 66 (25th to 75th percentile, 33 to 95) months, 178 patients reached the primary end point. Patients in the lowest quartile of LVET (<260 ms) were at high risk for adverse events compared with those in the other quartiles of LVET (global p = 0.005), whereas the rate of events was similar for the other quartiles (p = NS for all). After adjustment for clinical predictors of outcome, including age, gender, history of atrial fibrillation, MR severity, and current recommended triggers for MV surgery in asymptomatic primary MR, LVET <260 ms was associated with an increased risk of events (adjusted hazard ratio 1.49, 95% confidence interval 1.03 to 2.16, p = 0.033). In conclusion, we observed that shorter LVET is associated with increased risk of adverse events in patients with moderate or severe primary MR because of prolapse. Further studies are required to investigate whether shorter LVET has a direct effect on outcomes or is solely a risk marker in primary MR.

Segmentation of Echocardiography Based on Deep Learning Model

In order to achieve the classification of mitral regurgitation, a deep learning network VDS-UNET was designed to automatically segment the critical regions of echocardiography with three sections of apical two-chamber, apical three-chamber, and apical four-chamber. First, an expert-labeled dataset of 153 echocardiographic videos and 2183 images from 49 subjects was constructed. Then, the convolution layer in the VGG16 network was used to replace the contraction path in the original UNet network to extract image features, and depth supervision was added to the expansion path to achieve the segmentation of LA, LV, and MV. The results showed that the Dice coefficients of LA, LV, and MV were 0.935, 0.915, and 0.757, respectively. The proposed deep learning network can achieve simultaneous and accurate segmentation of LA, LV, and MV in multi-section echocardiography, laying a foundation for quantitative measurement of clinical parameters related to mitral regurgitation.

Evaluation of Patients for Percutaneous Edge-to-edge Mitral Valve Repair: Comparison of Cardiac Computed Tomography Angiography With Transesophageal Echocardiography

PURPOSE

We sought to compare parameters derived from cardiac computed tomography angiography (CCTA) with those from transesophageal echocardiography (TEE) for the evaluation of patients with severe mitral regurgitation (MR) before percutaneous edge-to-edge mitral valve repair (PE2E). TEE is the mainstay for PE2E, although it has specific limitations. CCTA enables measurements in any arbitrary plane with high spatial resolution and offers good calcium visibility.

MATERIALS AND METHODS

Patients who underwent TEE and CCTA before scheduled PE2E at 2 medical centers were included in this retrospective analysis. Quantitative parameters relevant for PE2E were obtained from TEE and CCTA in a blinded manner and the intrareviewer variability was assessed.

RESULTS

All 30 patients (15 female, 76±10 y) had secondary MR attributable to ischemic (60%) or nonischemic cardiomyopathy (40%). On comparing parameters from TEE and CCTA, left ventricular end-diastolic diameter was 60±11 versus 64±11 mm (r=0.90), intercommissural mitral annulus was 35±5 versus 35±5 mm (r=0.88), long-axis annulus was 33±5 versus 33±5 mm (r=0.74), the distance between the fossa ovalis and the leaflet coaptation was 42±5 versus 41±5 mm (r=0.81), the anterior mitral leaflet was 21±6 versus 20±7 mm (r=0.81), the posterior mitral leaflet was 13±2 versus 13±2 mm (r=0.91), and the median mitral calcification was 1 (interquartile range: 0 to 2) versus 0 (interquartile range: 0 to 1; r=0.53), respectively. Intrareviewer agreement was good and excellent for continuous and categorical variables, respectively.

CONCLUSIONS

Our data suggest that evaluation of the mitral valve apparatus with CCTA in patients considered for PE2E is feasible, correlates well with TEE, and offers improved calcium visibility. In selected cases, additional information from CCTA may be helpful for achieving optimal interventional results.

Cardiac Damage Staging Classification in Asymptomatic Moderate or Severe Primary Mitral Regurgitation

Background

Optimal timing for intervention remains uncertain in asymptomatic patients with primary mitral regurgitation (MR). We aimed to assess the prognostic value of a new cardiac damage staging classification in patients with asymptomatic moderate or severe primary MR.

Methods

Clinical, Doppler-echocardiographic, and outcome data prospectively collected in 338 asymptomatic patients (64 ± 15 years, 68% men) with at least moderate primary MR were retrospectively analyzed. Patients were hierarchically classified as per the following staging classification: no cardiac damage (stage 0), mild left ventricular or left atrial damage (stage 1), moderate or severe left ventricular or left atrial damage (stage 2), pulmonary vasculature or tricuspid valve damage (stage 3), or right ventricular damage (stage 4).

Results

There was a stepwise increase in 10-year mortality rates as per cardiac damage stage: 20.0% in stage 0, 25.6% in stage 1, 31.5% in stage 2, and 61.3% in stage 3-4 (p < 0.001). The staging classification was significantly associated with increased risk of mortality (hazard ratio = 1.41 per one-stage increase, 95% confidence interval: 1.07-1.85, p = 0.015) and the composite of cardiovascular mortality or hospitalization (hazard ratio = 1.51 per one-stage increase, 95% confidence interval: 1.07-2.15, p = 0.020) in multivariable analysis adjusted for EuroSCORE II, mitral valve intervention as a time-dependent variable, and other risk factors. The proposed scheme showed incremental value over several clinical variables (net reclassification index = 0.40, p = 0.03).

Conclusions

The new staging classification provides independent and incremental prognostic value in patients with asymptomatic moderate or severe MR.

Plausible Functional Diagnostics by Rational Echocardiography in the Assessment of Valvular Heart Disease - Role of Quantitative Echocardiography in the Assessment of Mitral Regurgitation

The echocardiographic assessment of valvular heart diseases is the basic analysis of valvular defects next to clinical investigation and stethoscopy. Severity of mitral regurgitation (MR) is usually estimated by an integrated approach using semi quantitative parameters and is still one of the biggest challenges of echocardiography. Quantitative echocardiographic analysis of MR severity often fails to describe comprehensible hemodynamic conditions. However, comprehensive echocardiography based on standardized image acquisition and proper image quality is required to properly assess hemodynamic parameter comparable to cardiac magnetic resonance tomography. This review focuses on the uncertainty of MR severity assessed by echocardiography in recent trials of interventional MR treatment. In addition, the necessity to provide plausible echocardiographic data for individual decision making is highlighted. In conclusion, plausible functional diagnostics by rational echocardiography is a prerequisite in patients with valvular heart diseases.

Sex Differences and Similarities in Valvular Heart Disease

As populations age worldwide, the burden of valvular heart disease has grown exponentially, and so has the proportion of affected women. Although rheumatic valve disease is declining in high-income countries, degenerative age-related causes are rising. Calcific aortic stenosis and degenerative mitral regurgitation affect a significant proportion of elderly women, particularly those with comorbidities. Women with valvular heart disease have been underrepresented in many of the landmark studies which form the basis for guideline recommendations. As a consequence, surgical referrals in women have often been delayed, with worse postoperative outcomes compared with men. As described in this review, a more recent effort to include women in research studies and clinical trials has increased our knowledge about sex-based differences in epidemiology, pathophysiology, diagnostic criteria, treatment options, outcomes, and prognosis.

Concomitant Mitral Regurgitation in Patients Undergoing Surgical Aortic Valve Replacement for Aortic Stenosis: A Systematic Review

Background: Concomitant mitral regurgitation (MR) is frequently seen in patients undergoing surgical aortic valve replacement (AVR) for severe aortic stenosis (AS). When the severity of MR is moderate or less, the decision to undertake simultaneous mitral valve intervention can be challenging.

Methods: A systematic search of Medline, PubMed (NCBI), Embase and Cochrane Library was conducted to qualitatively assess the current evidence for concomitant mitral valve intervention for MR in patients with AS undergoing AVR. The primary outcome for this systematic review was the postoperative change in the severity of MR and other outcomes of interest included factors that predict improvement or persistence of MR and long-term impacts of residual MR.

Results: A total of 17 studies were included. The percentage of patients demonstrating improvement in MR severity following AVR ranged from 17.2% to 72%; the studies that exclusively included patients with moderate functional MR and reported longer term echocardiographic follow-up of greater than 12 months demonstrated an improvement in MR severity of 45% to 72%.

Conclusion: This systematic review demonstrates that a proportion of patients can exhibit an improvement in MR following isolated surgical AVR, but whether this confers any long-term morbidity and mortality benefit remains unclear.

Adjunctive Techniques for Repair of Ischaemic Mitral Regurgitation

Ischaemic mitral regurgitation is a complex process with debate in the literature as to the optimal treatment pathway. Multiple therapies are available to alleviate mitral regurgitation including medical management, transcatheter edge-to-edge repair, mitral valve repair and mitral valve replacement. Medical management with goal-directed therapy should be utilised in patients with heart failure and mild-to-moderate regurgitation. Transcatheter approaches are typically used in patients with prohibitive operative risk, although their use is expanding, especially in those with functional mitral regurgitation who are not responding to goal-directed medical therapy. It is generally accepted that patients with mild-to-moderate disease can avoid valve intervention if successful revascularisation is performed. A higher consideration should be given to valve replacement over repair in patients with severe mitral regurgitation in the setting of myocardial ischaemia. Operative course must be personalised to each patient, and continues to develop with improving technologies and ongoing research into optimal treatment.

Automatic morphological classification of mitral valve diseases in echocardiographic images based on explainable deep learning methods

PURPOSE

Carpentier's functional classification is a guide to explain the types of mitral valve regurgitation based on morphological features. There are four types of pathological morphologies, regardless of the presence or absence of mitral regurgitation: Type I, normal; Type II, mitral valve prolapse; Type IIIa, mitral valve stenosis; and Type IIIb, restricted mitral leaflet motion. The aim of this study was to automatically classify mitral valves using echocardiographic images.

METHODS

In our procedure, after the classification of apical 4-chamber (A4C) and parasternal long-axis (PLA) views, we extracted the systolic/diastolic phase of the cardiac cycle by calculating the left ventricular area. Six typical pre-trained models were fine-tuned with a 4-class model for the PLA and a 3-class model for the A4C views. As an additional contribution, to provide explainability, we applied the Gradient-weighted Class Activation Mapping (Grad-CAM) algorithm to visualize areas of echocardiographic images where the different models generated a prediction.

RESULTS

This approach conferred a proper understanding of where various networks "look" into echocardiographic images to predict the four types of pathological mitral valve morphologies. Considering the accuracy metric and Grad-CAM maps and by applying the Inception-ResNet-v2 architecture to classify Type II in the PLA view and ResNeXt50 architecture to classify the other three classes in the A4C view, we achieved an 80% rate of model accuracy in the test data set.

CONCLUSIONS

We suggest an explainable, fully automated, and rule-based procedure to classify the four types of mitral valve morphologies based on Carpentier's functional classification using deep learning on transthoracic echocardiographic images. Our study results infer the feasibility of the use of deep learning models to prepare quick and precise assessments of mitral valve morphologies in echocardiograms. According to our knowledge, our study is the first one that provides a public data set regarding the Carpentier classification of MV pathologies.

Direct mitral regurgitation quantification in hypertrophic cardiomyopathy using 4D flow CMR jet tracking: evaluation in comparison to conventional CMR

BACKGROUND

Quantitative evaluation of mitral regurgitation (MR) in hypertrophic cardiomyopathy (HCM) by cardiovascular magnetic resonance (CMR) relies on an indirect volumetric calculation. The aim of this study was to directly assess and quantify MR jets in patients with HCM using 4D flow CMR jet tracking in comparison to standard-of-care CMR indirect volumetric method.

METHODS

This retrospective study included patients with HCM undergoing 4D flow CMR. By the indirect volumetric method from CMR, MR volume was quantified as left ventricular stroke volume minus forward aortic volume. By 4D flow CMR direct jet tracking, multiplanar reformatted planes were positioned in the peak velocity of the MR jet during systole to calculate through-plane regurgitant flow. MR severity was collected for agreement analysis from a clinical echocardiograms performed within 1 month of CMR. Inter-method and inter-observer agreement were assessed by intraclass correlation coefficient (ICC), Bland-Altman analysis, and Cohen's kappa.

RESULTS

Thirty-seven patients with HCM were included. Direct jet tracking demonstrated good inter-method agreement of MR volume compared to the indirect volumetric method (ICC = 0.80, p = 0.004) and fair agreement of MR severity (kappa = 0.27, p = 0.03). Direct jet tracking showed higher agreement with echocardiography (kappa = 0.35, p = 0.04) than indirect volumetric method (kappa = 0.16, p = 0.35). Inter-observer reproducibility of indirect volumetric method components revealed the lowest reproducibility in end-systolic volume (ICC = 0.69, p = 0.15). Indirect volumetric method showed good agreement of MR volume (ICC = 0.80, p = 0.003) and fair agreement of MR severity (kappa = 0.38, p < 0.001). Direct jet tracking demonstrated (1) excellent inter-observer reproducibility of MR volume (ICC = 0.97, p < 0.001) and MR severity (kappa = 0.84, p < 0.001) and (2) excellent intra-observer reproducibility of MR volume (ICC = 0.98, p < 0.001) and MR severity (kappa = 0.88, p < 0.001).

CONCLUSIONS

Quantifying MR and assessing MR severity by indirect volumetric method in HCM patients has limited inter-observer reproducibility. 4D flow CMR jet tracking is a potential alternative technique to directly quantify and assess MR severity with excellent inter- and intra-observer reproducibility and higher agreement with echocardiography in this population.

Incidence and standardised definitions of mitral valve leaflet adverse events after transcatheter mitral valve repair: the EXPAND study

BACKGROUND

An independent panel of experts reviewed all investigator-reported cases of mitral valve leaflet adverse events (LAE) after MitraClip NTR/XTR in the EXPAND study.

AIMS

We aimed to report the findings of the expert panel and standardise definitions for LAE.

METHODS

Standard definitions for different types of LAE were formulated and events adjudicated after detailed review by the expert panel.

RESULTS

Enrolling centres reported LAE in 35 cases, 11 leaflet injuries (9 tears, 2 perforations) and 24 single leaflet device attachment (SLDA). The panel confirmed LAE in 20 cases (2.0% incidence), 18 patients had SLDA and 4 had leaflet injury (2 cases had both SLDA and injury). Leaflet injury occurred during device implant and resulted in surgical valve replacement or death. SLDA-alone events were identified during implant (n=2), pre-discharge (n=7) or at 30 days of follow-up (n=7) and were resolved (≤2+ residual MR) with additional clips in 75% of cases.

CONCLUSIONS

Mitral valve repair with MitraClip NTR/XTR is safe. The rate of LAE is lower than previously reported using older-generation devices. The proposed definitions and findings will help to differentiate leaflet injury from inadequate leaflet insertion and SLDA and provide guidance for consistent diagnosis of LAE post MitraClip implantation.