Impact of eccentric jet on outcomes in patients with atrial functional mitral regurgitation: An echocardiographic study

BACKGROUND

Previous studies have reported the mechanisms underlying atrial functional mitral regurgitation (A-FMR). Recently, A-FMR subtypes based on mitral regurgitation (MR) mechanisms were proposed: "central jet" due to insufficient leaflet remodeling and "eccentric jet" due to atriogenic tethering. However, their prognostic value remains unclear. Therefore, this study investigated the impact of A-FMR subtypes on clinical outcomes.

METHODS

Outpatients with significant A-FMR between January 2013 and December 2016 were retrospectively reviewed. They were classified into two subtypes according to the MR jet's direction. All-cause mortality, heart failure hospitalization, and any mitral valve interventions were the primary composite endpoint.

RESULTS

Among 101 patients with significant A-FMR, 32% had eccentric jet. The primary endpoint was observed in 56 patients during the follow-up period (median 0.7 years, range 0.1-4.2 years). Kaplan-Meier curves demonstrated that the composite endpoint was higher among patients with eccentric jet than those with central jet (log-rank p < 0.001). Eccentric jet (hazard ratio [HR] 2.46, 95% confidence interval [CI] 1.28-4.73; p = 0.007), age (HR 1.06, 95% CI 1.02-1.11; p = 0.002), symptoms (HR 6.22, 95% CI 2.18-17.8; p < 0.001), severe MR (HR 3.97, 95% CI 1.92-8.18; p < 0.001), and significant tricuspid regurgitation (TR; HR 2.00, 95% CI 1.01-3.97; p = 0.047) were independent predictors of the composite endpoint.

CONCLUSIONS

Patients with eccentric jet had poorer outcomes than those with central jet. Eccentric jet, age, symptoms, severe MR, and significant TR were independently associated with poor outcomes.

Incidence and causal association of functional atrial mitral regurgitation in HFpEF

Heart failure with preserved ejection fraction (HFpEF) is as common as heart failure with reduced ejection fraction. Atrial fibrillation (AF), as well as the presence of mitral regurgitation (MR), is highly prevalent in these patients. Atrial functional MR (AFMR) is a type of functional MR characterized by severe left atrial dilatation and remodeling with normal left ventricular (LV) dimensions and function. Dilatation of the mitral annulus is considered to be the main underlying mechanism, though the leaflets and the rest of the mitral apparatus play significant role in the development of MR, mainly in patients with long standing AF. There are several echocardiographic differences between atrial and ventricular functional MR, better identified with 3D echocardiography. Significant AFMR impairs prognosis, especially of patients with HFpEF, and this is important while they represent a group of under-diagnosed and under-treated patients. Finally, because focused medical evidence-based approach is not available yet, it seems that the prevention of left atrial dilatation and early restoration of sinus rhythm (SR) is the best therapeutic option.

The atrial secondary tricuspid regurgitation is associated to more favorable outcome than the ventricular phenotype

Aim

We sought to evaluate the differences in prognosis between the atrial (A-STR) and the ventricular (V-STR) phenotypes of secondary tricuspid regurgitation.

Materials and methods

Consecutive patients with moderate or severe STR referred for echocardiography were enrolled. A-STR and V-STR were defined according to the last ACC/AHA guidelines criteria. The primary endpoint was the composite of all-cause death and heart failure (HF) hospitalizations.

Results

A total of 211 patients were enrolled. The prevalence of A-STR in our cohort was 26%. Patients with A- STR were significantly older and with lower NYHA functional class than V-STR patients. The prevalence of severe STR was similar (28% in A-STR vs. 37% in V-STR, p = 0.291). A-STR patients had smaller tenting height (TH) (10 ± 4 mm vs. 12 ± 7 mm, p = 0.023), larger end-diastolic tricuspid annulus area (9 ± 2 cm2 vs. 7 ± 6 cm2/m2, p = 0.007), smaller right ventricular (RV) end-diastolic volumes (72 ± 27 ml/m2 vs. 92 ± 38 ml/m2; p = 0.001), and better RV longitudinal function (18 ± 7 mm vs. 16 ± 6 mm; p = 0.126 for TAPSE, and −21 ± 5% vs. −18 ± 5%; p = 0.006, for RV free-wall longitudinal strain, RVFWLS) than V-STR patients. Conversely, RV ejection fraction (RVEF, 48 ± 10% vs. 46 ± 11%, p = 0.257) and maximal right atrial volumes (64 ± 38 ml/m2 vs. 55 ± 23 ml/m2, p = 0.327) were similar between the two groups. After a median follow-up of 10 months, patients with V-STR had a 2.7-fold higher risk (HR: 2.7, 95% CI 95% = 1.3–5.7) of experiencing the combined endpoint than A-STR patients. The factors related to outcomes resulted different between the two STR phenotypes: TR-severity (HR: 5.8, CI 95% = 1, 4–25, P = 0.019) in A-STR patients; TR severity (HR 2.9, 95% CI 1.4–6.3, p = 0.005), RVEF (HR: 0.97, 95% CI 0.94–0.99, p = 0.044), and RVFWLS (HR: 0.93, 95% CI 0.85–0.98, p = 0.009) in V-STR.

Conclusion

Almost one-third of patients referred to the echocardiography laboratory for significant STR have A-STR. A-STR patients had a lower incidence of the combined endpoint than V-STR patients. Moreover, while TR severity was the only independent factor associated to outcome in A-STR patients, TR severity and RV function were independently associated with outcome in V-STR patients.

Mitral Regurgitation and Mortality Risk in Medicare Beneficiaries With Heart Failure and Preserved Ejection Fraction

The association of mitral regurgitation (MR) severity and mortality in heart failure with preserved ejection fraction (HFpEF) is uncertain. We sought to evaluate the relation between MR severity on transthoracic echocardiography (TTE) and subsequent all-cause mortality in Medicare beneficiaries with HFpEF. We linked 57,608 patients referred for TTE at Beth Israel Deaconess Medical Center to Medicare inpatient claims from 2003 to 2017. In those with a history of HF and a physician-reported left ventricular ejection fraction ≥50%, we evaluated the relation of MR severity and time to the primary end point of all-cause mortality using Kaplan-Meier methods. A total of 7,778 individuals (14.5%) met inclusion criteria (mean age 75.5 years ± 11.9, 55.9% female). Over a median follow-up of 8.1 years, 2,016 (25.9%) died at a median (interquartile range) of 1.7 (0.3 to 4.1) years. At 1 year, 15.8% with 3 to 4+ MR had died versus 10.5% with 0 to 2+ MR (hazard ratio 1.54, 95% confidence interval 1.22 to 1.95, p <0.001). After multivariable adjustment, 3 to 4+ MR continued to be associated with increased all-cause mortality (hazard ratio 1.48, 95% confidence interval 1.14 to 1.94, p = 0.004) except in the subset with atrial fibrillation (interaction p = 0.03) or recent (<3 months) HF hospitalization (p = 0.54). In conclusion, in this large, single-institution retrospective study of Medicare beneficiaries with HFpEF who underwent TTE, moderate-to-severe and severe MR were significantly associated with an increased risk of all-cause mortality after multivariable adjustment, except in those with atrial fibrillation or recent HF. Prospective studies are needed to assess the role of MR reduction in mitigating this risk.

Mitral Annulus Geometry and Dynamic Motion Changes in Patients With Aortic Regurgitation: A Three-Dimensional Transesophageal Echocardiographic Study

OBJECTIVE

The aim of the present study was to investigate the mitral annulus (MA) geometry and dynamic motion changes in patients with aortic regurgitation (AR) before and after aortic valve replacement (AVR). Moreover, the difference in the effect of the type of prosthetic aortic valve on MA was compared.

DESIGN

Prospective observational study.

SETTING

Cardiac operating room at a single hospital.

PARTICIPANTS

Eighty-two patients with isolated moderate-to-severe AR who underwent AVR. Forty patients with normal valves were enrolled as controls.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The MA geometry and dynamic motion throughout the cardiac cycle were evaluated semiautomatically by three-dimensional transesophageal echocardiography. The severity of functional mitral regurgitation was intraoperatively evaluated. All patients were divided into 2 groups depending on the type of prosthetic valve (mechanical valve and bioprosthetic valve groups). Before AVR, compared with the control group without AR, the AR group demonstrated larger MA dimensions and the MA geometry was flatter. The contraction fraction of the MA area, perimeter, and height during the whole cardiac cycle were larger in the AR group (p < 0.05 for all). After AVR, most MA geometric and dynamic parameters decreased and functional mitral regurgitation also improved. In the postoperative subset analyses, the mechanical valve group showed a larger contraction fraction of the MA area and perimeter than the bioprosthetic valve group (p < 0.05 for both).

CONCLUSIONS

The MA geometry and dynamic motion changed markedly in patients with AR. These spatial and dynamic changes were restored to a certain extent after surgical correction of the aortic valve. However, the effects produced by mechanical and bioprosthetic valves on MA were different.

The Role of the Left Atrium: From Multimodality Imaging to Clinical Practice: A Review

In recent years, new interest is growing in the left atrium (LA). LA functional analysis and measurement have an essential role in cardiac function evaluation. Left atrial size and function are key elements during the noninvasive analysis of diastolic function in several heart diseases. The LA represents a “neuroendocrine organ” with high sensitivity to the nervous, endocrine, and immune systems. New insights highlight the importance of left atrial structural, contractile, and/or electrophysiological changes, introducing the concept of “atrial cardiomyopathy”, which is closely linked to underlying heart disease, arrhythmias, and conditions such as aging. The diagnostic algorithm for atrial cardiomyopathy should follow a stepwise approach, combining risk factors, clinical characteristics, and imaging. Constant advances in imaging techniques offer superb opportunities for a comprehensive evaluation of LA function, underlying specific mechanisms, and patterns of progression. In this literature review, we aim to suggest a practical, stepwise algorithm with integrative multimodality imaging and a clinical approach for LA geometry and functional analysis. This integrates diastolic flow analysis with LA remodelling by the application of traditional and new diagnostic imaging techniques in several clinical settings such as heart failure (HF), atrial fibrillation (AF), coronary artery disease (CAD), and mitral regurgitation (MR).

Three-dimensional echocardiography for predicting mitral stenosis after MitraClip for functional mitral regurgitation

BACKGROUND

Postprocedural mitral stenosis (MS), or increased transmitral mean pressure gradient (TMPG), is one of the limitations of transcatheter edge-to-edge mitral valve repair using MitraClip (Abbott Vascular Inc., Santa Clara, USA); however, the usefulness of three-dimensional transesophageal echocardiography (3D-TEE) for predicting postprocedural MS in functional mitral regurgitation (MR) has not been fully elucidated.

METHODS

Eighty-two consecutive functional MR patients who underwent transcatheter mitral valve repair using MitraClip were retrospectively studied. Postprocedural MS was defined as TMPG ≥ 5 mmHg by echocardiography.

RESULTS

Ten patients had postprocedural MS, and 3D-TEE showed that patients with postprocedural MS had smaller preprocedural mitral valve orifice area (MVOA), anteroposterior and mediolateral diameter, leaflet area, and annulus area. Receiver operating characteristic analysis showed that leaflet area (area under the curve (AUC) 0.829), annulus area (AUC 0.813), anteroposterior diameter (AUC 0.797) and mediolateral diameter (AUC 0.803) evaluated using 3D-TEE were predictors of postprocedural MS, and their predictive abilities were higher than those of preprocedural MVOA (AUC 0.756) and preprocedural TMPG (AUC 0.716). Adding leaflet area to TMPG and MVOA resulted in higher C-statistics for predicting postprocedural MS (from 0.716 to 0.845 and from 0.756 to 0.853, respectively).

CONCLUSIONS

In functional MR patients treated with MitraClip, leaflet area and annulus area evaluated using 3D-TEE had high predictive values for postprocedural MS, and their predictive abilities were higher than those of preprocedural TMPG or MVOA.

Differences in mitral valve geometry between atrial and ventricular functional mitral regurgitation in patients with atrial fibrillation: a 3D transoesophageal echocardiography study

AIMS

This study investigated geometric differences in mitral valve apparatus between atrial functional mitral regurgitation (A-FMR) and functional mitral regurgitation (FMR) with left ventricular (LV) dysfunction in patients with atrial fibrillation (AF) using 3D transoesophageal echocardiography (TOE).

METHODS AND RESULTS

In total, 135 moderate or greater FMR patients with persistent AF or atrial flutter underwent 3D TOE. Fifty-six patients had A-FMR, defined as preserved LV ejection fraction (LVEF) of ≥50% and normal LV wall motion. Seventy-nine patients had ventricular FMR (V-FMR), defined as LV dysfunction (LVEF of <50%) or LV wall motion abnormality. To evaluate mitral leaflet coaptation, the coapted area was calculated as follows: total leaflet area (TLA) in end-diastole - closed leaflet area in mid-systole. Although annular area (AA) did not significantly differ between the two groups, TLA was significantly smaller in A-FMR than in V-FMR (P = 0.005). TLA/AA, indicating the degree of the leaflet remodelling, was significantly smaller in A-FMR than in V-FMR (P < 0.001). A-FMR had significantly smaller posterior mitral leaflet tethering height and angle measured at three anteroposterior planes (lateral, central, and medial) than V-FMR (all P < 0.001). However, vena contracta width (VCW) measured on long-axis view on TOE and coapted area, which correlated with VCW (r = -0.464, P < 0.001), were similar between the two groups.

CONCLUSION

Mitral leaflet remodelling may be less in A-FMR compared with V-FMR. However, leaflet tethering was smaller in A-FMR than in V-FMR, and this may result in a similar degree of mitral leaflet coaptation and mitral regurgitation severity.

Severe Atrial Functional Mitral Regurgitation: Clinical and Echocardiographic Characteristics, Management and Outcomes

OBJECTIVES

This study was designed to compare the clinical and echocardiographic characteristics, management, and outcomes of severe atrial functional mitral regurgitation (AFMR) to primary mitral regurgitation (PMR).

BACKGROUND

AFMR remains poorly defined clinically.

METHODS

Consecutive patients who underwent transesophageal echocardiography at our institution between 2011 and 2018 for severe mitral regurgitation with preserved left ventricular function were screened. We excluded patients with endocarditis, any form of cardiomyopathy, or prior mitral intervention. The absence of leaflet pathology defined AFMR. Outcomes included death and heart failure hospitalizations.

RESULTS

A total of 283 patients were included (AFMR = 14%, PMR = 86%). Compared to PMR, patients with AFMR had more comorbidities, including hypertension (94.9% vs. 76.2%; p = 0.015), diabetes mellitus (46.2% vs. 18.4%; p < 0.001), long-standing atrial fibrillation (28.2% vs. 13.1%; p = 0.015), prior nonmitral cardiac surgery (25.6% vs. 9.8%; p = 0.004), and pacemaker placement (33.3% vs. 13.5%; p = 0.002). They also had higher average E/e' (median [interquartile range]:16.04 [13.1 to 22.46] vs. 14.1 [10.89 to 19]; p = 0.036) and worse longitudinal left atrial strain peak positive value (16.86 ± 12.15% vs. 23.67 ± 14.09%; p = 0.002) compared to PMR. During follow-up (median: 22 months), patients with AFMR had worse survival (log-rank p = 0.009) and more heart failure hospitalizations (log-rank p = 0.002). They were also less likely to undergo mitral valve intervention (59.0% vs. 83.6%; p = 0.001), although surgery was associated with improved survival (log-rank p = 0.021). On multivariable regression analysis, AFMR was independently associated with mortality [adjusted odds ratio: 2.61, 95% confidence interval: 1.17 to 5.83; p = 0.02].

CONCLUSIONS

AFMR constitutes an under-recognized high-risk group, with significant comorbidities, limited therapeutic options, and poor outcomes.

Mitral Annular Dynamics in AF Versus Sinus Rhythm: Novel Insights Into the Mechanism of AFMR

OBJECTIVES

This study aimed to investigate mitral annular dynamics in atrial fibrillation (AF) and after sinus rhythm restoration, and to assess the relationship between annular dynamics and mitral regurgitation (MR).

BACKGROUND

AF can be associated with MR that improves after sinus rhythm restoration. Mechanisms underlying this atrial functional MR (AFMR) are ill-understood and generally attributed to left atrial remodeling.

METHODS

Fifty-three patients with persistent AF and normal left ventricular ejection fraction were prospectively examined by means of 3-dimensional transesophageal echocardiography before, immediately after, and 6 weeks after electric cardioversion to sinus rhythm. Annular motion was assessed during AF and in sinus rhythm with the use of 3-dimensional analysis software, and the relationship with MR severity was explored.

RESULTS

During AF and immediately after sinus rhythm restoration, the mitral annulus behaved relatively adynamically, with an overall change in annular area of 10.3% (95% CI: 8.7%-11.8%) and 12.2% (95% CI: 10.6%-13.8%), respectively. At follow-up, a significant increase in annular dynamics (19.0%; 95% CI: 17.4%-20.6%; P < 0.001) was observed, owing predominantly to an increase in presystolic contraction (P < 0.001). The effective regurgitant orifice area decreased from 0.15 cm² (0.10 cm²-0.23 cm²) during AF to 0.09 cm² (0.05 cm²-0.12 cm²) at follow-up (P < 0.001) in the total cohort, and from 0.27 (0.23-0.33) to 0.16 (0.12-0.29) in the subgroup with effective regurgitant orifice area (EROA) ≥0.20 cm². The change in presystolic annular motion was the only independent determinant of the decrease in MR severity (P = 0.027), by optimizing annular-leaflet imbalance. Patients with more pronounced blunting of presystolic dynamics had a higher EROA (P < 0.001), because of a lower total-to-closed leaflet area ratio (P < 0.001) at each point in time. This ratio was the strongest independent determinant of AFMR severity (adjusted P = 0.003).

CONCLUSIONS

Mitral annular dynamics are impaired in AF, with blunted presystolic narrowing that contributes to AFMR. Sinus rhythm restoration allows gradual recovery of presystolic annular dynamics. Improved annular dynamics decrease AFMR severity by optimizing annular-leaflet imbalance, regardless of LA remodeling.

Understanding tricuspid valve remodelling in atrial fibrillation using three-dimensional echocardiography

AIMS

Atrial fibrillation (AF) has been associated with tricuspid annulus (TA) dilation in patients with severe functional tricuspid regurgitation (TR); however, the impact of AF is less clear in patients without severe TR. Our aim was to characterize TA remodelling in patients with AF in the absence of severe TR using 3D transoesophageal echocardiography (TOE).

METHODS AND RESULTS

Ninety patients underwent clinically indicated transthoracic and TOE: non-structural (NS)-AF (n = 30); AF with left heart disease (LHD) (n = 30), and controls in sinus rhythm (n = 30). Three-dimensional TOE datasets were analysed to measure TA dimensions using novel dedicated tricuspid valve software. The NS-AF group showed biatrial dilatation and normal right ventricular (RV) size with decreased longitudinal function compared to controls, whereas the LHD-AF group showed biatrial dilatation, RV enlargement, decreased biventricular function, and higher systolic pulmonary artery pressure compared with the other groups. Indexed TA area, minimum diameter, maximum diameter, and total perimeter were significantly larger in the NS-AF group than in controls (measurements in end-diastole: 6.4 ± 1.1 vs. 5.0 ± 0.6 cm2/m2, 1.8 ± 0.3 vs. 1.6 ± 0.2 cm/m2, 2.1 ± 0.3 vs. 1.9 ± 0.2 cm/m2, and 6.6 ± 0.9 vs. 5.9 ± 0.7 cm/m2, respectively, all P < 0.05). There was no significant difference in any indexed TA parameter between AF groups. TA circularity index (ratio between minimum and maximal diameters) and TA fractional area change between end-diastole and end-systole were no different among the three groups.

CONCLUSION

AF is associated with right atrial and tricuspid annular remodelling independent of the presence of LHD in patients with intrinsically normal tricuspid leaflets without severe TR.

Surgical considerations for atrial functional regurgitation of the mitral and tricuspid valves based on the etiological mechanism

Atrial functional mitral regurgitation is a hot research topic in the field of mitral valve disease. Atrial functional mitral regurgitation is distinctly different from ventricular functional mitral regurgitation. The surgical indications for atrial functional mitral regurgitation have not been well established because of the small amount of evidence gathered to date. Mitral annular plication with an artificial ring is an essential surgical procedure because dilatation of the mitral valve annulus is a main factor underlying this pathology. Most of these cases can be treated by mitral annuloplasty alone. However, additional procedures, such as application of artificial chordae to the anterior leaflet for pseudo-prolapse, and posterior leaflet augmentation with a pericardial patch, are required in advanced cases with a giant left atrium and extremely enlarged mitral annulus. Chronic atrial fibrillation causes enlargement of the right and left atria. This pathology is a bilateral atrioventricular valve disease (dual-valve disease). Therefore, the conventional guidelines of single-valve disease should not be applied. Although atrial functional tricuspid regurgitation is underappreciated, tricuspid annuloplasty should be considered for most patients to prevent future regurgitation. In addition to the mitral and tricuspid valve procedure, integrated surgical management, including plication of the atrium and left appendage closure, is required. This review summarizes the current considerations of surgical treatment for atrial functional regurgitation of the mitral and tricuspid valves based on the etiological mechanism.

Paroxysmal Severe Mitral Regurgitation

OBJECTIVE

To investigate the clinical presentation, pathophysiology, and treatment for "paroxysmal severe mitral regurgitation" (MR), which is an underappreciated cause of heart failure with preserved left ventricular ejection fraction.

METHODS

We retrospectively reviewed cases of transient severe MR that were evaluated at Mayo Clinic in Rochester, Minnesota, between January 1, 2006, and December 31, 2019. Paroxysmal severe MR was defined as the appearance of transient severe MR in patients with mild MR at rest, normal left ventricle (LV) size, left ventricular ejection fraction greater than 40%, and absence of obstructive coronary artery disease.

RESULTS

We identified 6 patients (5 women) with a median age of 68 years. There were 3 distinct mechanisms of paroxysmal severe MR, which we labeled types 1, 2, and 3. Type 1 MR was caused by LV dyssynchrony from a rate-dependent left bundle branch block, which led to apical leaflet tenting and incomplete coaptation. Type 2 MR occurred from mitral annular dilatation during maneuvers that increased left-sided volume. Type 3 MR was caused by coronary artery vasospasm with apical leaflet tenting. Treatments varied depending on the underlying cause and included cardiac resynchronization therapy for type 1, surgical valve replacement for type 2, and medical therapy for type 3.

CONCLUSION

Paroxysmal severe MR is a rare cause of heart failure in patients with preserved LV function. We have identified 3 distinct mechanisms that can lead to this dynamic process, with treatments varying based on the underlying cause.

Insufficient Mitral Leaflet Remodeling in Relation to Annular Dilation and Risk of Residual Mitral Regurgitation After MitraClip Implantation

OBJECTIVES

The purpose of this study was to determine whether the mitral valve (MV) total leaflet area (TLA)-to-mitral annular area (MAA) (TLA/MAA) ratio measured using 3-dimensional (3D) transesophageal echocardiography (TEE) was associated with residual mitral regurgitation (MR) after MitraClip implantation in patients with secondary MR.

BACKGROUND

The factors influencing the results of MitraClip implantation for secondary MR are controversial. This study hypothesized that insufficient remodeling of the mitral leaflets relative to the annular dilation may be associated with significant MR after MitraClip implantation.

METHODS

This study included patients with secondary MR treated with MitraClips. Using 3D TEE dataset, the TLA in diastole and MAA in systole were measured with dedicated software.

RESULTS

In a total cohort of 119 patients (mean age 74 ± 9 years; 61% male), significant residual MR (≥2+) was present in 43 patients (36%). In patients with significant residual MR, MAA was greater than in patients without residual MR (10.7 ± 2.4 cm² vs. 9.0 ± 2.1 cm²; p < 0.001) whereas no significant difference was observed in TLA (12.2 ± 2.6 cm² vs. 12.0 ± 2.9 cm²; p = 0.836). TLA/MAA ratio was lower in patients with significant residual MR as compared to their counterparts (1.14 ± 0.15 vs. 1.34 ± 0.16; p < 0.001), suggesting insufficient leaflet remodeling relative to annular dilation. On receiver-operating characteristic curve analysis, the TLA/MAA ratio had better discriminative power to identify patients who will have significant residual MR compared to MAA alone (area under the curve [AUC]: 0.830 vs. 0.723; p = 0.049).

CONCLUSIONS

In patients with secondary MR, insufficient mitral leaflet remodeling relative to the annulus dilation, as reflected by a lower TLA/MAA ratio, is associated with significant residual MR after MitraClip implantation.

Mitral Valve Repair of Atrial Functional Mitral Regurgitation in Heart Failure with Preserved Ejection Fraction

Our objective was to describe the long-term effects of endoscopic mitral valve (MV) repair on outcome in patients with heart failure with preserved ejection fraction (HFpEF) and atrial functional mitral regurgitation (AFMR). In patients with HFpEF, even mild AFMR has been associated with poor outcome. The study population consisted of consecutive patients with HFpEF (left ventricular ejection fraction (LVEF) ≥ 50%, H₂FPEF score ≥ 5) and AFMR, who underwent isolated, minimally invasive endoscopic MV repair (MVRepair group) (n = 131) or remained on standard of care (StanCare group) (n = 139). Patients with coronary artery disease or organic mitral regurgitation (MR) were excluded. Patients were matched using inverse probability of treatment weighting. Endpoints were all-cause mortality and a composite of all-cause mortality and HFpEF readmissions. The median follow-up was 5.03 years (interquartile range (IQR) 2.6–7.9 years). In the MVRepair group, the perioperative, 30-day, 1-year, and 5-year mortality were 0, 1%, 1%, and 12%, respectively. Additionally, 13 (10%) patients were readmitted for worsening HFpEF, while 2 (1%) individuals underwent redo MV surgery for recurrent MR. MVRepair compared with StanCare showed 21–29% (Standard Error (SE) 6–8%) and 19–26% (SE 6–8%) absolute risk reduction of all-cause mortality and HFpEF readmissions, respectively (all p < 0.05). MVRepair emerged as the strongest independent predictor of all-cause mortality (Hazard Ratio (HR) 0.16, 95% (Confidence Interval (CI) 0.07–0.34, p < 0.001) and HFpEF readmissions (HR 0.21, 95% CI 0.09–0.51, p < 0.001). At 5-year follow-up, in the MVRepair group, a total of 88% were alive and 80% were alive without readmission for HFpEF. We can conclude that endoscopic MV repair is associated with low perioperative mortality as well as high long-term efficacy, and appears to improve clinical outcome in patients with AFMR and HFpEF.

Midterm results of mitral valve repair for atrial functional mitral regurgitation: a retrospective study

Background

Annular dilation by left atrial remodeling is considered the main cause of atrial function mitral regurgitation. Although acceptable outcomes have been obtained using mitral ring annuloplasty alone for atrial functional mitral regurgitation, data assessing outcomes of this procedure are limited. Therefore, we aimed to assess midterm outcomes of mitral valve repair in patients with atrial functional mitral regurgitation.

Methods

We retrospectively studied 40 patients (mean age: 69 ± 9 years) who had atrial fibrillation that persisted for > 1 year, preserved left ventricular ejection fraction of > 40%, and mitral valve repair for atrial functional mitral regurgitation. The mean clinical follow-up duration was 42 ± 24 months.

Results

Mitral ring annuloplasty was performed for all patients. Additional repair including anterior mitral leaflet neochordoplasty was performed for 22 patients. Concomitant procedures included maze procedure in 20 patients and tricuspid ring annuloplasty in 31 patients. Follow-up echocardiography showed significant decreases in left atrial dimensions and left ventricular end-diastolic dimensions. Recurrent mitral regurgitation due to ring detachment or leaflet tethering was observed in five patients and was seen more frequently among those with preoperative left ventricular dilatation. Three patients without tricuspid ring annuloplasty or sinus rhythm recovery by maze procedure developed significant tricuspid regurgitation. Five patients who underwent the maze procedure showed sinus rhythm recovery. Rates of freedom from re-admission for heart failure at 1 and 5 years after surgery were 95 and 86%, respectively.

Conclusions

Mitral valve repair is not sufficient to prevent recurrent atrial functional mitral regurgitation in patients with preoperative left ventricular dilatation. Tricuspid ring annuloplasty may be required for long-term prevention of significant tricuspid regurgitation.

Update of Patient Selection and Therapeutic Strategy Using MitraClip

Patients with advanced heart failure often accompany severe function mitral regurgitation refractory to optimal medical therapy. Degenerative mitral regurgitation also develops due to various degeneration of mitral valve. Surgical intervention to the mitral valve might be effective in some cases, but it is challenging for the high-risk cases. Recently, percutaneous edge-to-edge mitral valve repair using the MitraClip system, which enables us to approach the mitral valve at relatively low risk, has developed. Two major prospective randomized control trials have been conducted to investigate the clinical advantage of MitraClip system over optimal medical therapy in patients with severe mitral regurgitation; both showed controversial conclusions. Now is a time to consider optimal patient selection and therapeutic strategy using MitraClip system.

Atrial functional mitral regurgitation

PURPOSE OF REVIEW

To review the prevalence and prognosis of atrial functional mitral regurgitation (AFMR), the distinctive echocardiographic and mechanistic findings, and the therapeutic implications of this newly described disorder.

RECENT FINDINGS

Initial studies identified an association between atrial fibrillation, mitral annular dilation, and significant mitral regurgitation despite a normal mitral valve and left ventricle. Accumulating data suggest that AFMR is not rare and may have a prognosis as poor as functional MR associated with LV remodeling. Echocardiography has played an important role in understanding the unique pathophysiology of AFMR, and proposed mechanisms include not only atrial remodeling, but structural and functional abnormalities of the LV (HFpEF shares a common pathophysiology) and insufficient leaflet growth. Timely rhythm control of atrial fibrillation and strategies that reduce diastolic pressure, left atrial and mitral annular enlargement, and that favorably affect mitral leaflet adaptation, are promising preventive and treatment options that warrant clinical study.

SUMMARY

Functional mitral regurgitation may be atrial in origin and should be considered in patients with (particularly long-standing) atrial fibrillation and in those with HFpEF.

The change in the mitral-septal angle after surgery for atrial functional mitral regurgitation

OBJECTIVE

The optimal surgical strategy for atrial functional mitral regurgitation remains uncertain. Preoperative mitral-septal angle ≤ 70° has been reported as a risk factor for an abnormal vortex pattern in mitral valve repair. This study aimed to elucidate the change in the mitral-septal angle after surgery for atrial functional mitral regurgitation and its effect on the mid-term outcomes.

METHODS

Forty patients underwent mitral valve repair for atrial functional mitral regurgitation. The mitral-septal angle was defined as the angle between the mitral annulus and the anteroseptal wall of the left ventricular mid-portion in the parasternal long-axis view on transthoracic echocardiography. All patients underwent mitral ring annuloplasty. Left atrial plication was performed in nine patients. The mean clinical follow-up period was 42 ± 24 months.

RESULTS

The ratio of left atrial volume to left ventricular end-systolic volume was negatively correlated with the preoperative mitral-septal angle. The postoperative mitral-septal angles were significantly smaller than the preoperative ones. The mitral-septal angle decreased with a decrease in the mitral annuloplasty ring size. Patients who underwent left atrial plication tended to show an increase in the mitral-septal angle postoperatively. There were no significant differences in mid-term morbidities, including heart failure, requiring re-hospitalization and mortalities between patients with postoperative MSA > 70° and those with postoperative MSA ≤ 70°.

CONCLUSIONS

Mitral ring annuloplasty negatively changed the mitral-septal angle, while left atrial plication may induce a positive change to the mitral-septal angle. An association between the mitral-septal angle and mid-term outcomes was not revealed in this study.

Reverse Remodeling of the Mitral Valve Complex After Radiofrequency Catheter Ablation for Atrial Fibrillation

Background:

Mitral regurgitation is frequently complicated with atrial fibrillation without apparent organic changes in the leaflet, which occasionally improves after successful radiofrequency catheter ablation. We aimed to evaluate a possible geometric effect of radiofrequency catheter ablation on the mitral valve apparatus.

Methods:

Forty-three consecutive patients who underwent successful catheter ablation for persistent atrial fibrillation (maintaining sinus rhythm for 6 months after their procedure) were examined by serial real-time 3-dimensional transesophageal echocardiography before and 6 months after catheter ablation. Mitral valve complex geometry was measured using dedicated software for 3-dimensional transesophageal echocardiography.

Results:

Mitral valve apparatus showed significant reverse remodeling along with left atrial reverse remodeling 6 months after successful catheter ablation (50.5 [39.2–61.0] versus 36.4 [28.9–43.1] mL/m 2 ; P <0.001). The degree of mitral regurgitation decreased in a majority of patients (mitral regurgitation jet area; 1.83 [0.78–3.09] versus 0.77 [0.36–1.47] cm 2 ; P <0.001). Annular area significantly decreased (5.32±0.91 versus 4.73±0.76 cm 2 /m 2 ; P <0.001) in both anterior-posterior and medial-lateral directions. Mitral annular contraction significantly recovered after maintaining sinus rhythm for 6 months (7.51 [4.82–9.62]% versus 9.71 [6.27–13.85]%; P =0.008). There were no significant changes in tenting volume or tenting height (0.46 [0.27–0.89] versus 0.51 [0.32–0.72] mL/m 2 , P =0.744; 2.34 [1.75–3.48] versus 2.76 [1.99–3.08] mm/m 2 , P =0.717). The leaflet surface area also significantly decreased after catheter ablation (5.74 [5.01–6.33] versus 5.19 [4.63–5.64] cm 2 /m 2 ; P <0.001).

Conclusions:

Maintaining sinus rhythm after successful catheter ablation promotes reverse remodeling in the mitral valve apparatus and improves so-called atrial functional mitral regurgitation. The positive geometric effect of catheter ablation would be expected to be a possible contributor to better outcomes in patients with atrial fibrillation, in addition to the postprocedural freedom from rhythm disturbance.

Mitral Valve Adaptation to Isolated Annular Dilation: Insights Into the Mechanism of Atrial Functional Mitral Regurgitation

OBJECTIVES

This study hypothesized that compensatory mitral leaflet area (MLA) adaptation occurs in patients with persistent atrial fibrillation (AF) without left ventricular (LV) dysfunction but has limitations that augment mitral regurgitation (MR). The study also explored whether asymmetrical annular dilation is matched by relative leaflet enlargement.

BACKGROUND

Functional MR occurs in patients with AF and isolated annular dilation, but the relationship of MLA adaptation with annular area (AA) is unknown.

METHODS

Three-dimensional echocardiographic images were acquired from 86 patients with quantified MR: 53 with nonvalvular persistent AF (23 MR+ with moderate or greater MR, 30 MR-) without LV dysfunction or dilation and 33 normal controls. Comprehensive 3-dimensional analysis included total diastolic MLA, adaptation ratios of MLA to annular area and MLA to leaflet closure area, and annular and tenting geometry.

RESULTS

Total MLA was 22% larger in patients with AF than in controls, thus paralleling the increased AA. However, as AA increased, adaptive indices (MLA/AA ratio and ratio of MLA to closure area) plateaued, becoming lowest in MR+ patients (ratio of MLA to closure area = 1.63 ± 0.17 controls, 1.60 ± 0.11 MR-, 1.32 ± 0.10 MR+; p < 0.001). MR increased as the ratio of MLA to closure area decreased (R2 = 0.68; p < 0.001). The posterior-to-anterior MLA ratio remained constant, whereas the posterior-to-anterior mitral annulus perimeter increased (1.21 ± 0.16 controls, 1.32 ± 0.20 MR-, 1.46 ± 0.19 MR+; p < 0.001). Multivariate MR determinants were annular area, total MLA to closure area, and posterior-to-anterior perimeter ratios.

CONCLUSIONS

MLA adaptively increases in AF with isolated annular dilation and normal LV function. This compensatory enlargement becomes insufficient with greater annular dilation, and the leaflets fail to match asymmetrical annular remodeling, thereby increasing MR. These findings can potentially help optimize therapeutic options and motivate basic studies of adaptive growth processes.

Valve Disease in Heart Failure: Secondary but Not Irrelevant

Secondary regurgitation caused by the remodeling and dysfunction of the left or right heart chamber may complicate heart failure, worsening both symptoms and prognosis. Outcome studies have shown that patients' prognosis worsened as the severity of secondary regurgitation increases. Imaging and more specifically echocardiography plays a central role for diagnosis and serial assessment of secondary regurgitation as well as for timing the intervention and guiding the procedure.

Mitral Annular and Left Ventricular Dynamics in Atrial Functional Mitral Regurgitation: A Three-Dimensional and Speckle-Tracking Echocardiographic Study

BACKGROUND

Patients with atrial fibrillation (AF) and left atrial (LA) enlargement may develop functional, normal leaflet motion mitral regurgitation (MR) without left ventricular (LV) remodeling. Mitral annular dynamics and LV mechanics are important for preserving normal mitral valve function. The aim of this study was to assess the annular and LV dynamics in patients with AF and functional MR.

METHODS

Twenty-one patients with AF with moderate or more MR (AFMR+ group), 46 matched patients with AF with no or mild MR (AFMR- group), and 19 normal patients were retrospectively studied. Mitral annular dynamics were quantitatively assessed using three-dimensional echocardiography. Systolic LV global longitudinal strain (GLS), global circumferential strain, and LA strain were measured using two-dimensional speckle-tracking echocardiography.

RESULTS

The normal annulus displayed presystolic followed by systolic contraction and increase in saddle shape (P < .01 for all). Presystolic annular dynamics were abolished in both groups of patients with AF (P > .05 vs normal). In contrast, systolic and total annular dynamics during the cardiac cycle were preserved in AFMR- patients (P > .10 vs normal) but impaired in AFMR+ patients (P < .05 vs normal and AFMR-). LV GLS (P < .0001) and LA strain (P = .02), but not LV global circumferential strain (P = .97), were impaired in AFMR+ compared with AFMR- patients despite comparable LA and LV volumes. MR severity correlated with systolic annular contraction (r = 0.64, P < .0001), saddle deepening (r = 0.53, P = .003), and LV GLS (r = 0.46, P < .0001). Multivariate analysis identified that impaired systolic contraction (odds ratio, 2.18; P = .001) and saddle deepening (odds ratio, 2.68; P = .04) were independently associated with MR. Excluding annular dynamics from the model, less negative LV GLS, but not LA strain, became associated with MR (odds ratio, 1.93; P < .0001).

CONCLUSIONS

In patients with AF and absent LA contraction, the normal predominantly "atriogenic" annular dynamics become "ventriculogenic." Isolated LA enlargement is insufficient to cause important MR without coexisting abnormal LV mechanics and annular dynamics during systole. "Atrial" functional MR may not be purely an atrial disorder.

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.

Quantitative analysis of mitral valve morphology in atrial functional mitral regurgitation using real-time 3-dimensional echocardiography atrial functional mitral regurgitation

Background

Atrial fibrillation (AF) can result in atrial functional mitral regurgitation (MR), but the mechanism remains controversial. Few data about the relationship between the 3-dimensional morphology of the MV and the degree of MR in AF exist.

Methods

Real-time 3-dimensional transesophageal echocardiography (3D-TEE) of the MV was acquired in 168 patients with AF (57.7% persistent AF), including 25 (14.9%) patients with moderate to severe MR (the MR+ group) and 25 patients without AF as controls. The 3-dimensional geometry of the MV apparatus was acquired using dedicated quantification software.

Results

Compared with the group of patients with no or mild MR (the MR- group) and the controls, the MR+ group had a larger left atrium (LA), a more dilated mitral annulus (MA), a reduced annular height to commissural width ratio (AHCWR), indicating flattening of the annular saddle shape, and greater leaflet surfaces and tethering. MR severity was correlated with the MA area (r² = 0.43, P < 0.01) and the annulus circumference (r² = 0.38, P < 0.01). A logistic regression analysis indicated that the MA area (OR: 1.02, 95% CI: 1.01–1.03, P < 0.01), AHCWR (OR: 0.24, 95% CI: 0.14–0.35, P = 0.04) and MV tenting volume (OR: 3.24, 95% CI: 1.16–9.08, P = 0.03) were independent predictors of MR severity in AF patients.

Conclusions

The mechanisms of “atrial functional MR” are complex and include dilation of the MA, flattening of the annular saddle shape and greater leaflet tethering.

Long-term mortality in patients with severe secondary mitral regurgitation and normal left ventricular ejection fraction: interventional perspective

AIMS

Patients with severe secondary mitral regurgitation (MR) and normal ejection fraction are being excluded from clinical trials evaluating transcatheter mitral devices. We sought to evaluate the long-term mortality with medical management alone in this patient population.

METHODS AND RESULTS

We retrospectively evaluated patients diagnosed with ≥3+ MR at our institution over 15 years. Only patients with an ejection fraction ≥60% were included in the study. Those with degenerative mitral valve disease, papillary muscle dysfunction, or hypertrophic cardiomyopathy, and those who underwent mitral valve intervention were excluded. The study included 400 patients (age 71.1±14.8, 25.1% male, ejection fraction 62.5±3.6%). Mechanism of secondary MR was restricted valve motion, annular dilation and apical tethering in 91.5, 4.5 and 4%, respectively. One-year and three-year mortality were 19.1 and 26.3%, respectively. On multivariable Cox proportional regression analysis, older age, New York Heart Association functional Class III or IV, >3+ MR and larger left atrium were independent predictors of mortality.

CONCLUSIONS

Severe secondary MR with normal left ventricular systolic function has significant mortality with medical management alone. This initial observation needs to be confirmed in larger prospective studies. These patients should be included in future transcatheter clinical trials.

Functional anatomy and pathophysiologic principles in mitral regurgitation: Non-invasive assessment

Mitral regurgitation (MR) is the most prevalent cause of valvular heart disease (VHD) in western countries. In the Euro Heart Survey on VHD, MR was the second most common heart VHD requiring surgery. It is also the most common form of VHD in community and population-based studies from the United States. The categorization of MR based on causes and mechanisms is a major determinant of clinical outcome, of possible therapies for the MR and of the effectiveness of these therapies. Surgical mitral valve (MV) repair has been shown to improve survival in patients with severe primary MR compared with MV replacement. In addition, new percutaneous repair and replacement procedures have been recently developed. Hence, accurate understanding of the functional anatomy of the MV and the pathophysiologic principles underlying MR is needed to appropriately target valve lesions. Recent advances in cardiac imaging have allowed to deeply strengthen the knowledge of the function of the MV. The present review aims at describing the functional anatomy and pathophysiology of MR through different cardiac imaging modalities.

Mechanism of atrial functional mitral regurgitation in patients with atrial fibrillation: A study using three-dimensional transesophageal echocardiography

BACKGROUND

Functional mitral regurgitation (MR) can occur in patients with atrial fibrillation (AF) despite having preserved left ventricular (LV) systolic function. This MR is known as atrial functional MR. The aim of this study was to clarify the mechanism of atrial functional MR using real-time three-dimensional transesophageal echocardiography (3DTEE).

METHODS

Sixty patients underwent transthoracic echocardiography and 3DTEE: 16 patients with AF and significant non-organic MR and preserved LV ejection fraction (>50%) constituted the AF-MR group, 20 patients with AF and no significant MR formed the AF-NSMR group, and 24 normal subjects comprised the control group.

RESULTS

The left atrial volume index was significantly larger in the AF-MR group (95±41ml/m²) than in the AF-NSMR group (38±13ml/m², p<0.05) or the control group (21±7ml/m², p<0.05). The 3D annular circumference was significantly longer in the AF-MR group than in the AF-NSMR group. The annular-anterior leaflet coaptation angle was smaller in the AF-MR group than in the AF-NSMR group (11±6° vs. 18±9°, p<0.05). The annular-posterior leaflet coaptation angle was comparable between the two AF groups (26±12° vs. 28±10°), whereas the annular-posterior leaflet tip angle was larger in the AF-MR group than in the AF-NSMR group (59±13° vs. 44±11°, p<0.05). The posterior leaflet bending toward LV cavity was therefore significantly larger in the AF-MR group than in the AF-NSMR group (32±10° vs. 18±15°, p<0.05).

CONCLUSIONS

In patients with AF and significant functional MR occurring despite their preserved LV systolic function, the left atrium and mitral annulus were dilated and the anterior leaflet was flattened along the mitral annular plane, whereas the posterior leaflet was bent toward the LV cavity.

Insufficient Leaflet Remodeling in Patients With Atrial Fibrillation

Background—

The relationship between annular dilatation caused by atrial fibrillation (AF) and mitral regurgitation (MR) remains controversial. We hypothesized that the small ratio of total leaflet area/annulus area (TLA/AA), reflecting insufficient leaflet remodeling to annular dilatation, is a main component of MR in patients with AF.

Methods and Results—

Three-dimensional transesophageal echocardiographic data of the mitral valve were analyzed in 28 AF patients with moderate or severe MR (MR group), age- and sex-matched 56 AF patients with mild or less MR (non-MR group), and 16 control subjects. AA was significantly greater in both the MR (645±126 mm 2 /m 2 , P <0.001) and non-MR groups (568±121 mm 2 /m 2 , P =0.001) compared with control subjects (444±108 mm 2 /m 2 ). However, TLA/AA was significantly smaller in the MR (1.29±0.10, P <0.001), but not in the non-MR group (1.65±0.24, P >0.99), compared with control subjects (1.70±0.29). In linear regression analysis, TLA/AA was inversely associated with the effective regurgitant orifice ( r =−0.73, P <0.001). The area under the receiver-operating-characteristics curve of TLA/AA was significantly greater than that of AA (0.95 versus 0.72, P <0.001). Multivariable analysis revealed that small TLA/AA ( P <0.001) was independently associated with significant MR, while AA was not ( P =0.26).

Conclusions—

In patients with AF, insufficient leaflet remodeling to annular dilatation, rather than crude annular dilatation, was strongly associated with the severity of MR.

Functional mitral regurgitation at discharge and outcomes in patients hospitalized for acute decompensated heart failure with a preserved or reduced ejection fraction

AIMS

The relationship between functional mitral regurgitation (FMR), left ventricular ejection fraction (EF), and outcomes is unclear in acute decompensated heart failure (HF) patients. The aim of this study was to evaluate the relationship between FMR and post-discharge outcomes in HF patients with a preserved or reduced EF.

METHODS AND RESULTS

Of the 4842 patients enrolled in the Acute Decompensated Heart Failure Syndromes (ATTEND) registry, 3357 patients were evaluated to assess the association among FMR (none, mild, or moderate/severe) at discharge, a preserved or reduced EF, and the primary endpoint (all-cause mortality and readmission for HF). The median follow-up period after discharge was 530 (387-800) days. According to multivariate analysis, patients with either mild FMR or moderate/severe FMR from the preserved EF group had a significantly higher risk of reaching the endpoint than patients without FMR [hazard ratio (HR) 1.40; 95% confidence interval (CI) 1.14-1.72; P = 0.001 and HR 1.40; 95% CI 1.09-1.81; P = 0.009, respectively]. In the reduced EF group, patients with moderate or severe FMR had a significantly higher risk relative to patients without FMR (HR 1.41; 95% CI 1.07-1.86; P = 0.015), but there was no significant association of mild FMR with the risk of reaching the endpoint (HR 1.09; 95% CI 0.84-1.42; P = 0.510).

CONCLUSION

Our findings demonstrate that even mild FMR is associated with an increased risk of adverse outcomes in HF patients with a preserved EF, while moderate or severe FMR (but not mild FMR) is associated with adverse outcomes in HF patients with a reduced EF.