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

Mitral regurgitation in atrial fibrillation: Is a simple repair enough to tackle a complex problem?

BACKGROUND

Clinical and echocardiographic results of valve repair for mitral regurgitation in the setting of atrial fibrillation are poorly studied.

METHODS

Between January 2008 and December 2020, 89 patients underwent valve repair for mitral regurgitation in the setting of atrial fibrillation. Clinical and echocardiographic follow-up data were collected and studied. The primary composite endpoint consisted of all-cause mortality or hospitalization for heart failure.

RESULTS

Valve repair with true-sized annuloplasty was performed in 83 (93 %) and restrictive annuloplasty in 6 (7 %) patients. Early mortality occurred in 3 (3 %) and residual mitral regurgitation in 1 (1 %) patient. During a median follow-up of 5.4 years (interquartile range 3.4-9.5), 25 patients died, 6 due to end-stage heart failure. Ten patients were hospitalized for heart failure. The estimated event-free survival rate at 10 years was 48.2 % (95 % CI 33.5 %-62.9 %). Recurrent mitral regurgitation was observed in 14 patients and most often caused by leaflet tethering. When analyzed as a time-dependent variable, recurrent regurgitation was related to the occurrence of the primary endpoint (hazard ratio 3.192, 95 % CI 1.219-8.359, p = 0.018). On exploratory sub-analyses, no recurrent regurgitation was observed after restrictive annuloplasty or in patients with paroxysmal atrial fibrillation. Moreover, recurrent regurgitation was observed more often when signs of left ventricular impairment were present preoperatively.

CONCLUSIONS

Despite good initial results, recurrent regurgitation was a frequent observation after valve repair for mitral regurgitation in atrial fibrillation and had an effect on heart failure related morbidity and mortality. Refinements in the timing of surgery and surgical technique might help improve outcomes.

Functional Mitral Regurgitation and Heart Failure With Preserved Ejection Fraction: Clinical Implications and Management

Heart failure with preserved ejection fraction (HFpEF) is highly prevalent and associated with worse cardiovascular outcomes. The pathophysiology of HFpEF mostly relies on the development of elevated left ventricle filling pressure, diastolic dysfunction, and atrial dilatation and impairment. This dynamic process may eventually lead to the development of functional mitral regurgitation (MR), characterized by mitral annular dilatation and consequent leaflet remodeling, in the context of preserved left ventricular ejection fraction. These observations highlight the possible common pathophysiology of MR and HFpEF. However, less is known about the prevalence and the clinical value of MR in the context of HFpEF. This review aims to provide an overview of the association and interplay between functional MR and HFpEF, discuss the underlying mechanisms that are common to these diseases, and summarize potential targeted pharmacological treatments.

Distinct leaflet-annular remodeling pattern in severe atrial functional mitral regurgitation: a three-dimensional echocardiography study

BACKGROUND

Atrial functional mitral regurgitation (AFMR) is best described with normal left ventricular size and function, structurally normal mitral leaflets and dilated left atrium. Unlike the ventricular functional phenotype, changes in the annular geometry more than the tethering forces are the main culprit for mitral regurgitation. The aim of this study is to illuminate the leaflet-annular remodeling in patients with mitral regurgitation and atrial fibrillation (AF) using three-dimensional transesophageal echocardiography (3D TOE).

RESULTS

Consecutive fifty patients with AFMR underwent transthoracic echocardiography and 3D TOE: 25 patients with AF and non-mild MR and 25 patients with AF and mild MR were studied. A special mitral valve analysis software was used to accurately assess the three unique pillars for MR: annular size, leaflets' geometry and tenting parameters. Compared to the mild MR group, non-mild MR group had long-standing AF of more than 1 year and larger left atrial volumes (51.83 ± 12.07 ml/m2 vs 33.68 ± 10.97 ml/m2, p < 0.001). No significant differences were noted in respect of tenting height, area and volume (13.06 ± 2.57 mm vs 11.43 ± 2.89 mm, p = 0.064, 3.58 ± 1.26 cm2 vs 2.80 ± 0.95 cm2, 0.081 and 6.70 ± 2.96 cm3 vs 5.04 ± 2.32 cm3, p = 0.081). Conversely, the non-mild MR group had larger annular area and perimeter (16.20 ± 3.90 cm2 vs 13.51 ± 3.85 cm2, p = 0.023 and 14.73 ± 1.72 cm vs 13.46 ± 1.79 cm, p = 0.033). Similarly, the non-mild MR group had larger anterior and posterior leaflets' areas (10.18 ± 4.02 cm2 vs 8.71 ± 3.08 cm2, p = 0.04 and 8.96 ± 2.60 cm2 vs 7.30 ± 2.17 cm2, p = 0.029). Correspondingly, more disproportionate leaflet-annular remodeling, as assessed by the ratio of total leaflets' area to the annular area, was noted in the non-mild MR as opposed to the mild MR group (1.22 ± 0.04 vs 1.26 ± 0.04, p = 0.008).

CONCLUSIONS

Recently, AFMR has been recognized as a remarkable entity of secondary MR with unique mechanisms. Annular dilatation with disproportionate leaflet remodeling can validate the central regurgitation. However, the call for more parameters is being emphasized to characterize the suitable candidates for percutaneous interventions.

Left Ventricular Papillary Muscle: Anatomy, Pathophysiology, and Multimodal Evaluation

As an integral part of the mitral valve apparatus, the left ventricle papillary muscle (PM) controls mitral valve closure during systole and participates in the ejection process during left ventricular systole. Mitral regurgitation (MR) is the most immediate and predominant result when the PM is structurally or functionally abnormal. However, dysfunction of the PM is easily underestimated or overlooked in clinical interventions for MR-related diseases. Therefore, adequate recognition of PM dysfunction and PM-derived MR is critical. In this review, we systematically describe the normal anatomical variations in the PM and the pathophysiology of PM dysfunction-related diseases and summarize the commonly used parameters and the advantages and disadvantages of various noninvasive imaging modalities for the structural and functional assessment of the PM.

Tricuspid valve and right-heart chamber remodelling in elderly subjects with secondary tricuspid regurgitation

BACKGROUND

The prevalence of secondary tricuspid regurgitation (TR) increases with ageing, but the exact mechanisms and the pattern of tricuspid valve (TV) remodelling are yet to be defined. This knowledge is needed to guide patient selection for the evolving therapeutic options. We sought to explore the prevalence and predictors of secondary TR in the elderly, as well as the associated pattern of right-heart chamber and TV remodelling.

METHODS

Consecutive older subjects (60-year-old or older) were prospectively enrolled and detailed analysis of right-heart chambers and TV was conducted (ClinicalTrials.gov ID: NCT05784883). TR severity was defined based on a multiparametric approach.

RESULTS

Out of 213 patients (age, 67.1 ± 5.9 years, 52.6% female), 48.8% had mild and 15.5% had moderate-severe TR. The frequency of moderate-severe TR increased from 4.5% in those without to 32.9% in those with underlying abnormalities of the left/right heart. There was a significant trend of worsening right-heart chamber and TV remodelling across the three grades of TR severity (none-trace, mild, and moderate-severe; p-value for linear trend < 0.001). ROC curve-defined cut-points of TV remodelling parameters predicting moderate-severe TR were annular dilatation ≥3.75 cm (AUC: 0.74), tenting area ≥1.45 cm2 (AUC: 0.67), and leaflet length ≥2.25 cm (AUC: 0.61) with increasing frequency of moderate-severe TR from 7.2% through 64.7%, in those with none vs. all three criteria (p < 0.001). The most important correlate of the three TV remodelling parameters was right ventricular and atrial (RV and RA) dilatation.

CONCLUSION

Rather than ageing per se, the presence of underlying cardiac abnormalities determines the frequency of moderate-severe TR. Progressive remodelling of right-heart chambers and TV geometry starts with the development of mild TR. TA dilatation, increased tenting, and leaflet elongation are three important correlates of the development of TR that parallel progressive RV and RA dilatation.Study Registration: ClinicalTrials.gov ID: NCT05784883.

Prevalence and prognostic impact of dynamic atrial functional mitral regurgitation assessed by isometric handgrip exercise

AIMS

In atrial functional mitral regurgitation (aFMR), a considerable proportion of patients displays a discrepancy between symptoms and echocardiographic findings at rest. Exercise testing plays a substantial role in assessing the haemodynamic relevance of mitral regurgitation (MR) and is recommended by current guidelines. Here, we aimed to assess the prevalence, extent, and prognostic impact of exercise-induced changes in patients with aFMR.

METHODS AND RESULTS

Patients with at least mild MR who underwent handgrip exercise echocardiography at the University Hospital Duesseldorf between January 2019 and September 2021 were enrolled. Patients were followed up for 1 year to assess clinical outcomes. Eighty patients with aFMR were included [median age: 80 (77-83) years; 53.8% female]. The median N-terminal pro-brain natriuretic peptide level was 1756 (1034-3340) ng/L. At rest, half of the patients (53.8%) had mild MR, 20 patients (25.0%) had moderate MR, and 17 patients (21.2%) had severe MR. In approximately every fifth patient (17.5%) with non-severe MR at rest, the MR became severe during exercise. Handgrip exercise led to a reclassification of MR severity in 28 patients (35.0%). At 1-year follow-up, adverse events occurred more often in patients with severe MR at rest (76.5%) and exercise-induced dynamic severe MR (66.7%) than in those with non-severe MR (28.6%; P < 0.001).

CONCLUSION

Handgrip exercise during echocardiography revealed exercise-induced changes in aFMR in every third patient. These data may have implications for therapeutic decision-making in symptomatic patients with non-severe aFMR at rest.

The Natural History of Atrial Functional Mitral Regurgitation

BACKGROUND

The natural history of moderate/severe atrial functional mitral regurgitation (AFMR) is unknown.

OBJECTIVES

The authors sought to study the incidence of left ventricular (LV) systolic dysfunction (LVSD), progression or regression of ≥mild-moderate AFMR, and impact on mortality.

METHODS

Adults with left atrial (LA) volume index ≥40 mL/m2, ≥mild-moderate AFMR, and follow-up echocardiogram were followed for incident LVSD (ejection fraction <50% and ≥10% lower than baseline), progression of mild-moderate/moderate AFMR to severe, and persistent regression of AFMR to no/trivial. Relation of AFMR progression or regression as time-dependent covariates with all-cause mortality was studied. Incidence of LVSD was compared with patients with no/mild AFMR matched on age, sex, comorbidities and ejection fraction. Patients were followed until mitral intervention, myocardial infarction, or last follow-up.

RESULTS

A total of 635 patients (median age 75 years, 51% female, 96% mild-moderate/moderate AFMR, 4% severe AFMR) were included. Over a median 2.2 years (Q1-Q3: 1.0-4.3 years), incidence rates per 100 person-years were 3.2 for LVSD (P = 0.52 vs patients with no/mild AFMR), 1.9 for progression of AFMR, and 3.9 for regression. Female sex and larger LA volume index were independently associated with progression, whereas younger age, male sex, absent atrial fibrillation, and higher LA emptying fraction were independently associated with regression. Neither AFMR progression nor regression was independently associated with mortality. Instead, independent risk factors for mortality included older age, concentric LV geometry, and higher estimated LV filling and pulmonary pressures.

CONCLUSIONS

In patients with predominantly mild-moderate/moderate AFMR, regression of MR was more common than progression, but neither was associated with mortality. Instead, diastolic function abnormalities were more important. Over a median 2-year follow-up, LVSD risk was not increased.

Assessing emerging causes of mitral regurgitation: atrial functional mitral regurgitation

Functional or secondary mitral regurgitation is linked to increased cardiovascular morbidity and mortality. From a mechanical perspective, secondary mitral regurgitation occurs due to an imbalance between the forces that tether the mitral leaflets and those that close them. This results in incomplete coaptation. Most commonly, functional mitral regurgitation, which occurs in both ischaemic and non-ischaemic disease states, is usually caused by dysfunction and changes in the left ventricle. Atrial functional mitral regurgitation (AFMR) is a disease state that has been more recently recognized. It occurs when mitral annular enlargement is associated with left atrial dilatation, preserving left ventricular geometry and function. AFMR is typically seen in patients with chronic atrial fibrillation or heart failure who have a conserved ejection fraction. Published reports and ongoing investigations vary in how they define AFMR. This publication examines the pathophysiology of AFMR and highlights the importance of having a common working standard for the definition of AFMR to ensure consistency in the data reported and to drive forward the much needed research into the outcomes and treatment strategies in this area. Several studies have reported that restrictive annuloplasty and transcatheter edge-to-edge repair can reduce mitral regurgitation and improve symptoms. This narrative review will explore the pathophysiology, echocardiographic diagnosis and treatment of AFMR.

Potential Effects of Mild Atrial Secondary Mitral Regurgitation in Patients With Isolated Atrial Fibrillation

BACKGROUND

Patients with only moderate atrial secondary mitral regurgitation (asMR) frequently develop heart failure (HF). Mechanisms of HF with moderate asMR and the impact of mild asMR remain unclarified. Although mild/moderate primary mitral regurgitation is compensated by left ventricular (LV) dilatation, the LV is not dilated in asMR. We hypothesized that patients with mild asMR without LV dilatation may have impaired hemodynamics and higher risks of subsequent symptomatic HF deterioration.

METHODS

Stroke volume, cardiac output, and systolic pulmonary artery pressure were measured by echocardiography in 142 patients with isolated atrial fibrillation and 30 healthy controls. The prognosis of patients with isolated atrial fibrillation was followed up.

RESULTS

In the 142 patients with isolated atrial fibrillation, asMR was no/trivial in 55, mild in 83, moderate in 4, while none had severe asMR. Compared with controls and patients with no/trivial asMR, LV end-diastolic volume index was not increased and hemodynamic parameters were abnormal in patients with mild asMR (LV end-diastolic volume index, 65±6 versus 58±8 versus 60±8 mL/m²; stroke volume index, 42±4 versus 35±4 versus 29±6 mL/m²; P<0.001 versus other 2 groups; cardiac output index, 2.8±0.4 versus 2.8±0.5 versus 2.3±0.6 L/min per m²; P<0.001; systolic pulmonary artery pressure, 21±3 versus 26±5 versus 37±9 mm Hg; P<0.001). Although the event-free rate of HF symptomatic deterioration or hospitalization in patients with no/trivial asMR during a median 13.9 months follow-up was 86.9% and 100%, the rate in mild asMR was 59.4% and 85.0% (P<0.001 or P=0.032), respectively.

CONCLUSIONS

In the presence of isolated AF and no compensatory LV dilatation, impaired hemodynamics and higher risks of symptomatic HF deterioration were associated with mild asMR, requiring further studies of causalities.

Optimizing Atrial Fibrillation Care: Comparative Assessment of Anticoagulant Therapies and Risk Factors

BACKGROUND AND OBJECTIVES

Atrial fibrillation (AF) is a common arrhythmia associated with various risk factors and significant morbidity and mortality.

MATERIALS AND METHODS

This article presents findings from a study involving 345 patients with permanent AF. This study examined demographics, risk factors, associated pathologies, complications, and anticoagulant therapy over the course of a year.

RESULTS

The results showed a slight predominance of AF in males (55%), with the highest incidence in individuals aged 75 and older (49%). Common risk factors included arterial hypertension (54%), dyslipidemia, diabetes mellitus type 2 (19.13%), and obesity (15.65%). Comorbidities such as congestive heart failure (35.6%), mitral valve regurgitation (60%), and dilated cardiomyopathy (32%) were prevalent among the patients. Major complications included congestive heart failure (32%), stroke (17%), and myocardial infarction (5%). Thromboembolic and bleeding risk assessment using CHA2DS2-VASc and HAS-BLED scores demonstrated a high thromboembolic risk in all patients. The majority of patients were receiving novel oral anticoagulants (NOACs) before admission (73%), while NOACs were also the most prescribed antithrombotic therapy at discharge (61%).

CONCLUSIONS

This study highlights the importance of risk factor management and appropriate anticoagulant therapy in patients with AF, to reduce complications and improve outcomes. The results support the importance of tailored therapeutic schemes, for optimal care of patients with AF.

Impact of Transcatheter Edge-to-Edge Mitral Valve Repair on Atrial Functional Mitral Regurgitation from the GIOTTO Registry

Atrial functional mitral regurgitation (aFMR) has a peculiar pathophysiology that may have distinctive outcomes. We investigated the impact of transcatheter edge-to-edge repair in aFMR compared with other FMR etiologies. The GIOTTO (GIse registry Of Transcatheter treatment of MR) is a multicenter, prospective study enrolling patients with symptomatic MR treated with MitraClip up to 2020. We categorized patients with FMR as aFMR, ischemic FMR (iFMR), and nonischemic ventricular FMR (niFMR). The clinical end points were defined according to the Mitral Valve Academic Research Consortium. Of 1,153 patients, 6% had aFMR, 47% iFMR, and 47% niFMR. Patients with aFMR were older, mostly women, and had a higher atrial fibrillation rate. They had better left ventricular ejection fraction and smaller left ventricular volumes, with no difference in mitral effective regurgitant orifice area. The acute device and procedural success rates were similar among the groups. At the longest available follow-up (median 478 days, interquartile range 91 to 741 days), the rate of MR ≥2+ was similar among the groups. Patients with aFMR had a lower rate of cardiovascular death and heart failure than patients with iFMR (hazard ratio [HR] 0.43, p = 0.02) and niFMR (HR 0.45, p = 0.03). The aFMR etiology remained independently associated with the composite outcome, together with postprocedural MR ≤1+ (HR 0.63, p <0.01) and peripheral arteriopathy (HR 1.82, p = 0.003). The results of this GIOTTO subanalysis suggested that aFMR is less prevalent and associated with better outcomes compared with other causes of FMR treated by transcatheter edge-to-edge repair. Postprocedural MR >1+, peripheral vasculopathy, non-aFMR were independent predictors of worse outcomes.

Multimodality Imaging for the Assessment of Mitral Valve Disease

Mitral valve disease is the most common valvular heart disease. Imaging determines the etiology (anatomic assessment), valve function and severity of valvular heart disease (hemodynamic assessment), remodeling of the left ventricle and right ventricle, and preplanning and guidance of percutaneous intervention. Although roles of computed tomography and magnetic resonance are increasing, echocardiography serves as the first-line imaging modality for the diagnosis and serial follow-up in most cases. This review summarizes the roles of multimodality imaging currently available from research fields to daily clinical practice.

Impact of left atrium plication on chronic heart failure with atrial functional mitral regurgitation

Purpose

We hypothesized that a giant left atrium may oppress  the posterior left ventricle and aggravate diastolic dysfunction and heart failure. We evaluated the effect of left atrial plication (LAP) on atrial functional mitral regurgitation.

Methods

We retrospectively reviewed patients who underwent LAP for atrial functional mitral regurgitation at our institution between January 2017 and December 2021. Early outcomes, follow-up echocardiography data, and heart failure indicators were compared.

Results

Eighteen patients were divided into two groups: LAP + (n = 9) or LAP- (n = 9). There were no significant differences in patient characteristics and preoperative echocardiographic parameters, except for the preoperative New York Heart Association classification. Operative (505.7 [standard deviation: 100.0] minutes vs. 382.9 [standard deviation: 58.1] minutes, P = .0055) and cardiopulmonary bypass times (335.6 [standard deviation: 50.4] minutes vs. 246.9 [standard deviation: 62.7] minutes, P = .0044) were significantly longer in the LAP + group. No in-hospital mortalities were observed in both groups. The postoperative left atrial volume was significantly reduced in the LAP + group, and mitral regurgitation was controlled at less than mild levels in both groups. At follow-up, the left ventricular end-diastolic volume was reduced significantly in the LAP + group. Brain natriuretic peptide, cardiothoracic ratio, and the New York Heart Association classification were improved in the LAP + group.

Conclusions

Additional left atrial plication contributes to the control of atrial functional mitral regurgitation and heart failure at a later stage. A careful long-term follow-up is needed as re-expansion of the left atrium is possible.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-023-01569-6.

Assessment of mitral valve geometry in nonvalvular atrial fibrillation patients with or without ventricular dysfunction: insights from high volume rate three-dimensional transesophageal echocardiography

Meticulous understanding of the mechanisms underpinning mitral regurgitation in atrial fibrillation (AF) patients is crucial to optimize therapeutic strategies. The morphologic characteristics of mitral valves in atrial functional mitral regurgitation (FMR) patients with and without left ventricular (LV) dysfunction were evaluated by high volume rate (HVR) three-dimensional transesophageal echocardiography (3D-TEE). In our study, 68 of 265 AF patients who underwent 3D-TEE were selected, including 36 patients with AF, FMR, and preserved LV function (AFMR group) and 32 patients with AF, FMR, and LV dysfunction (VFMR group). In addition, 36 fever patients without heart disease were included in the control group. Group comparisons were performed by one-way analysis of variance for continuous variables. The left atrium (LA) was enlarged in the AFMR and VFMR groups compared with the control group. The mitral annulus (MA) in the AFMR group was enlarged and flattened compared with the control group and was smaller than in the VFMR group. The annulus area fraction was significantly diminished in the AFMR and VFMR groups, indicative of reduced MA contractility. The posterior mitral leaflet (PML) angle was smallest in the AFMR group and largest in the control group, whereas the distal anterior mitral leaflet angle did not significantly differ among the three groups. LA remodeling causes expansion of the MA and reduced MA contractility, disruption of the annular saddle shape, and atriogenic PML tethering. Comparison of atrial FMR patients with and without LV dysfunction indicates that atriogenic PML tethering is an important factor that aggravates FMR. HVR 3D-TEE improves the 3D temporal resolution greatly.

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.

A geometry-based finite element tool for evaluating mitral valve biomechanics

Mitral valve function depends on its complex geometry and tissue health, with alterations in shape and tissue response affecting the long-term restorarion of function. Previous computational frameworks for biomechanical assessment are mostly based on patient-specific geometries; however, these are not flexible enough to yield a variety of models and assess mitral closure for individually tuned morphological parameters or material property representations. This study details the finite element approach implemented in our previously developed toolbox to assess mitral valve biomechanics and showcases its flexibility through the generation and biomechanical evaluation of different models. A healthy valve geometry was generated and its computational predictions for biomechanics validated against data in the literature. Moreover, two mitral valve models including geometric alterations associated with disease were generated and analysed. The healthy mitral valve model yielded biomechanical predictions in terms of valve closure dynamics, leaflet stresses and papillary muscle and chordae forces comparable to previous computational and experimental studies. Mitral valve function was compromised in geometries representing disease, expressed by the presence of regurgitating areas, elevated stress on the leaflets and unbalanced subvalvular apparatus forces. This showcases the flexibility of the toolbox concerning the generation of a range of mitral valve models with varying geometric definitions and material properties and the evaluation of their biomechanics.

Incidence, risk factors, and outcomes of atrial functional mitral regurgitation in patients with atrial fibrillation or sinus rhythm

AIMS

Atrial functional mitral regurgitation (AFMR) has been associated with atrial fibrillation (AF) and heart failure with preserved ejection fraction. However, data on incident AFMR are scarce. We aimed to study the incidence, risk factors, and clinical significance of AFMR in AF or sinus rhythm (SR).

METHODS AND RESULTS

Adults with new diagnosis of AF and adults in SR were identified. Patients with >mild MR at baseline, primary mitral disease, cardiomyopathy, left-sided valve disease, previous cardiac surgery, or with no follow-up echocardiogram were excluded. Diastolic dysfunction (DD) was indicated by ≥2/4 abnormal diastolic function parameters [mitral medial e', mitral medial E/e', tricuspid regurgitation velocity, left atrial volume index (LAVI)]. Overall, 1747 patients with AF and 29 623 in SR were included. Incidence rate of >mild AFMR was 2.6 per 100 person-year in new-onset AF and 0.7 per 100 person-year in SR, P < 0.001. AF remained associated with AFMR in a propensity score-matched analysis based on age, sex, and comorbidities between AF and SR [hazard ratio: 3.80 (95% confidence interval 3.04-4.76)]. Independent risk factors associated with incident AFMR were age ≥65 years, female sex, LAVI, and DD in both AF and SR, in addition to rate (vs. rhythm) control in AF. Incident AFMR was independently associated with all-cause death in both groups (both P < 0.001).

CONCLUSIONS

AF conferred a three-fold increase in the risk of incident AFMR. DD, older age, left atrial size, and female sex were independent risk factors in both SR and AF, while rhythm control was protective. AFMR was universally associated with worse mortality.

Perspectives on Secondary Mitral Regurgitation in Heart Failure

PURPOSE OF THE REVIEW

This review focuses on broader perspectives of mitral regurgitation (MR) in patients with heart failure.

RECENT FINDINGS

The ratio of regurgitant volume to end-diastolic volume appears to help identify patients who may benefit from valve interventions. Secondary MR is not only attributed to geometric changes of the LV but also related to the structural changes in the mitral valve that include fibrosis of the mitral leaflets and changes in the extracellular matrix. The transition from mild to severe secondary MR can occur at different rates, from a slow LV remodeling process to a more abrupt process precipitated by an inciting event such as atrial fibrillation. Septal flash and apical rocking, two new visual markers of LV mechanical dyssynchrony, appear to be predictive of MR reduction following cardiac resynchronization therapy. Optimal guideline-directed medical therapy has been shown to decrease the severity of secondary MR effectively. A theoretical framework to characterize secondary MR as it relates to the onset of MR is proposed. Type A: Early onset of MR contemporaneous with myocardial injury. The maladaptive LV remodeling occurs in parallel with MR. Type B: LV remodeling proceeds without significant MR until the LV is moderately dilated, which coincides with or without inciting factors such as atrial fibrillation. Type C: LV remodeling proceeds after myocardial injury without significant MR until the LV is severely dilated. MR is a late manifestation of LV remodeling.

Efficacy of catheter ablation for atrial fibrillation in patients with significant functional mitral regurgitation

BACKGROUND

Catheter ablation has been established to be an effective therapy for paroxysmal atrial fibrillation (AF) and is recommended as the treatment of choice for many patients, including those with clinically significant functional mitral regurgitation (MR). However, there is little information available about the clinical efficacy of catheter ablation for paroxysmal AF in patients with significant functional MR.

METHODS

We performed a retrospective study of 247 patients with paroxysmal AF who underwent AF ablation. The study included 28 (11.3%) patients with significant functional MR and 219 (88.7%) without significant functional MR. AF recurrence was defined as the occurrence of confirmed atrial tachyarrhythmia lasting >30 seconds beyond 3 months after catheter ablation.

RESULTS

During a mean follow-up of 20.1 ± 7.4 months (range, 3-36 months), 45 (18.2%) patients developed recurrence of AF. The recurrence rate of AF was higher in patients with significant functional MR than in those without significant functional MR (42.9% vs 15.1%; P < .001). Univariable Cox proportional hazards regression analysis showed that significant functional MR (hazard ratio [HR], 3.46; 95% confidence interval [CI], 1.78-6.72; P < .001), age (HR, 1.04; 95% CI, 1.01-1.08; P = .009), the CHA2DS2-VASc score (HR, 1.28; 95% CI, 1.05-1.56; P = .017), and heart failure (HR, 4.71; 95% CI, 1.85-11.96; P = .001) were associated with the risk of recurrence. Multivariable analysis showed that significant functional MR (HR, 2.48; 95% CI, 1.21-5.05; P = .013), age (HR, 1.04; 95% CI, 1.00-1.07; P = .031), and heart failure (HR, 3.39; 95% CI, 1.27-9.03; P = .015) were independent predictors of AF recurrence.

CONCLUSION

Patients with significant functional MR have an increased risk of AF recurrence after catheter ablation.

The journal of cardiovascular computed tomography: A year in review: 2022

This review aims to summarize key articles published in the Journal of Cardiovascular Computed Tomography (JCCT) in 2022, focusing on those that had the most scientific and educational impact. The JCCT continues to expand; the number of submissions, published manuscripts, cited articles, article downloads, social media presence, and impact factor continues to grow. The articles selected by the Editorial Board of the JCCT in this review highlight the role of cardiovascular computed tomography (CCT) to detect subclinical atherosclerosis, assess the functional relevance of stenoses, and plan invasive coronary and valve procedures. A section is dedicated to CCT in infants and other patients with congenital heart disease, in women, and to the importance of training in CT. In addition, we highlight key consensus documents and guidelines published in JCCT last year. The Journal values the tremendous work by authors, reviewers, and editors to accomplish these contributions.

Prognostic impact of left ventricular global longitudinal strain in atrial mitral regurgitation

OBJECTIVE

Left atrial (LA) and left ventricular (LV) mechanics are impaired in patients with atrial functional mitral regurgitation (AFMR), but their prognostic value in this subset of patients remains unknown. The present study aimed to evaluate the association between LA and LV longitudinal strain and clinical outcomes in patients with AFMR.

METHODS

A total of 197 patients (mean age 73±10 years, 44% men) with at least moderate AFMR were retrospectively identified. LV global longitudinal strain (GLS) and left atrial reservoir strain (LAS) were calculated by two-dimensional speckle tracking echocardiography. All-cause mortality was the primary endpoint of the study. The threshold value of LV GLS (≤16.3%) to identify impaired LV mechanics was defined based on the risk excess of the primary endpoint described with a spline curve analysis.

RESULTS

Impaired LV GLS (≤16.3%) was found in 89 (45%) patients. During a median follow-up of 69 months, 45 (23%) subjects experienced the primary endpoint. Patients with impaired LV GLS (≤16.3%) had a significantly lower cumulative survival rate at 5 years, as compared with patients with LV GLS (>16.3%) (74% vs 93%, p<0.001). On multivariable Cox regression analysis, LV GLS expressed as continuous variable was independently associated with the occurrence of all-cause mortality (HR 0.856, 95% CI 0.763 to 0.960; p=0.008) after adjustment for age, LAS, pulmonary artery systolic pressure and severe tricuspid regurgitation. Conversely, LAS was not significantly associated with patients' outcome.

CONCLUSIONS

In patients with significant AFMR, the impairment of LV GLS was independently associated with worse outcomes.

Differences in clinical and echocardiographic features and outcomes between atrial functional mitral regurgitation patients with and without posterior mitral leaflet bending

BACKGROUND

Posterior mitral leaflet (PML) bending is a cause of atrial functional mitral regurgitation (AFMR). We aimed to investigate differences in clinical and echocardiographic features and outcomes between AFMR patients with and without PML bending.

METHODS

We retrospectively examined 118 AFMR patients with atrial fibrillation (AF), mild or greater MR without degenerative mitral valve changes, and left ventricular ejection fraction ≥50 %. Patients were classified by the presence of PML bending: PML bending (n=24) and no PML bending (n=94). PML bending was defined as PML-to-anterior mitral leaflet angle ratio ≥3.1 calculated using receiver operating characteristics analysis for eccentric MR jet toward left atrial posterior wall. The study endpoint was a composite of cardiac death, admission for heart failure, and mitral valve surgery.

RESULTS

Overall, a total of 88 patients (75 %) had mild MR. There were no between-group differences in clinical and echocardiographic characteristics including AF duration and cardiac cavities size except for the length of inward bending of the left ventricular posterobasal wall and the mitral annular area. The 36-month event-free survival for the composite endpoint was significantly lower in the PML bending group (63 % vs. 78 %; Log-rank p=0.047). In multivariate analysis, PML bending was also associated with the composite outcome.

CONCLUSIONS

AFMR patients with PML bending may have worse outcomes than those without PML bending despite similar clinical features.

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.

Pathophysiology, Echocardiographic Diagnosis, and Treatment of Atrial Functional Mitral Regurgitation: JACC State-of-the-Art Review

The conventional view holds that functional mitral regurgitation (MR) is caused by restriction of leaflet motion resulting from displacement of the papillary muscle-bearing segments of the left ventricle. In the past decade, evidence has accrued suggesting functional MR can also be caused by left atrial enlargement. This underrecognized cause of secondary MR-atrial functional MR (AF-MR)-is mechanistically linked to annular enlargement, perturbations of annular contraction, and atriogenic leaflet tethering. AF-MR has been described in patients with atrial fibrillation and heart failure with preserved ejection fraction. Preliminary data suggest rhythm control may decrease MR severity in patients with atrial fibrillation. Additionally, several studies have reported reductions in MR and symptomatic improvement with restrictive annuloplasty and transcatheter edge-to-edge repair. This review discusses the pathophysiology, echocardiographic diagnosis, and treatment of AF-MR. AF-tricuspid regurgitation is also discussed.

Mitral valve repair and concomitant maze procedure versus catheter ablation in the treatment of atrial functional mitral regurgitation

BACKGROUND

To compare mitral valve (MV) repair and concomitant maze procedure with catheter ablation in treating patients with atrial functional mitral regurgitation (AFMR).

METHODS

We retrospectively identified 126 patients with AFMR from January 2012 to December 2015. Of these patients, 60 patients underwent MV repair and concomitant maze procedure, and 66 patients received catheter ablation. Patients were followed up for 7.98 ± 2.01 years. The survival, readmission of heart failure (HF), persistent atrial fibrillation (AF), persistent moderate-severe mitral regurgitation (MR) and tricuspid Regurgitation (TR), and echocardiographic data were analyzed in the follow-up. Predictors of readmission of HF were analyzed.

RESULTS

There was no significant difference in baseline and echocardiographic characteristics, in-hospital mortality, and other adverse events postoperatively between two groups. The surgical group was associated with lower rates of MR > 2 + grade either at discharge (P = 0.0023) or in the follow-up (P = 0.0001). There was no significant difference in the incidence of overall survival between the two groups. The surgical group was associated with a lower rate of readmission of HF and AF in the follow-up. Univariable and multivariable analysis confirmed AF at discharge, moderate-severe MR at discharge, no MV surgery, moderate-severe TR at discharge, and LA volume as predictors of readmission of HF. Both groups experienced significant reverse cardiac remodeling.

CONCLUSIONS

Our results suggest that for the treatment of AFMR with persistent or long-standing persistent AF and moderate-severe MR, MV repair and concomitant maze procedure may achieve a better outcome than catheter ablation procedure.

Atrial Functional Mitral Regurgitation: A JACC: Cardiovascular Imaging Expert Panel Viewpoint

Functional or secondary mitral regurgitation (MR) is associated with increased cardiovascular morbidity and mortality. Mechanistically, secondary MR is attributable to an imbalance between mitral leaflet tethering and closure forces, leading to poor coaptation. The pathophysiology of functional MR is most often the result of abnormalities in left ventricular function and remodeling, seen in ischemic or nonischemic conditions. Less commonly and more recently recognized is the scenario in which left ventricular geometry and function are preserved, the culprit being mitral annular enlargement associated with left atrial dilatation, termed atrial functional mitral regurgitation (AFMR). This most commonly occurs in the setting of chronic atrial fibrillation or heart failure with preserved ejection fraction. There is variability in the published reports and in current investigations as to the definition of AFMR. This paper reviews the pathophysiology of AFMR and focus on the need for a collective definition of AFMR to facilitate consistency in reported data and enhance much-needed research into outcomes and treatment strategies in AFMR.

The Prevalence and Characteristics of Mitral Regurgitation in Heart Failure: A Chart Review Study

Background

Mitral regurgitation (MR) is one of the common complications of heart failure (HF). The prevalence and characteristics of MR are rarely investigated, especially in the Chinese population.

Objectives

The purpose of this study was to determine the prevalence and characteristics of non-organic MR in HF patients and subgroups defined by ejection fraction.

Methods

A single-center, hospital-based, and retrospective chart review study included patients with heart failure admitted to the cardiovascular department from January 2017 to April 2020. Demographic characteristics, laboratory results, and echocardiogram results before discharge were analyzed in different groups defined by left ventricular ejection fraction (EF) using logistic regression and adjusted for confounders.

Results

Finally, 2418 validated HF patients (age 67.2 ± 13.5 years; 68.03% men) were included. The prevalence of MR was 32.7% in HF, 16.7% in HF with preserve EF patients, 28.4% in HF with mid-range EF patients and 49.7% in HF with reduced EF (HFrEF) patients. In the HF with preserved EF group, multivariable logistic regression showed that 4 factors associated with MR including EF (odds ratio (OR) 0.954 (0.928-0.981), p = 0.001), left ventricular posterior wall thickness in diastolic phase (LVPWd) (OR 0.274 (0.081-0.932), p = 0.038), left atrium (LA) dimension (OR 2.049 (1.631-2.576), p < 0.001) and age (OR 1.024 (1.007-1.041), p = 0.007). In the HF with midrange EF group, multivariable logistic regression showed that 3 factors associated with MR including LA dimension (OR 2.009 (1.427-2.829), p < 0.001), triglycerides (TG) (OR 0.552 (0.359-0.849), p = 0.007) and digoxin (OR 2.836 (1.624-4.951), p < 0.001). In the HFrEF group, multivariable logistic regression showed that 7 factors associated with MR including EF (OR 0.969 (0.949-0.990), p = 0.004), (OR 0.161 (0.067-0.387), p < 0.001), LA dimension (OR 2.289 (1.821-2.878), p < 0.001), age (OR 1.016 (1.004-1.027)), p = 0.009), TG (OR 0.746 (0.595-0.936), p = 0.011), diuretics (OR 0.559 (0.334-0.934), p = 0.026) and ICD (OR 1.898 (1.074-3.354), p = 0.027).

Conclusions

HF patients had a high burden of MR, particularly in the HFrEF group. Worsen cardiac structure (LA dimension and LVPWd) and function (EF), age, and medical treatment strategy played essential roles in MR.

Atrial Mitral and Tricuspid Regurgitation: Sex Matters. A Call for Action to Unravel the Differences Between Women and Men

Atrial functional regurgitation is caused by atrioventricular annulus dilation, with normal leaflets and ventricular dimensions and function within the normal range. Its occurrence, in both mitral and tricuspid valves, implies a worse prognosis due to the hemodynamic derangement they produce, but also constitutes a marker of greater comorbidity and more advanced disease. Predisposing conditions for these heart valve dysfunctions are mainly atrial fibrillation and heart failure with preserved ejection fraction. However, other factors like female sex also may be involved and influence their incidence, especially for atrial tricuspid regurgitation. In the present review, we analyze sex differences in the reported prevalence of atrial mitral and tricuspid regurgitation, and suggest possible mechanisms involved. Finally, we underline potential therapeutic and preventive strategies to reduce the burden of these heart valve disorders and discuss research gaps.

Clinical, functional and prognostic implications of severe atrial dilation in secondary mitral regurgitation

Objective

Atrial dilation is known to be a poor prognostic indicator. However, its clinical, functional and prognostic implications have not been thoroughly explored in secondary mitral regurgitation (SMR). We sought to describe the implications of severe atrial dilation (SAD) in SMR.

Methods

We included all adult patients with severe SMR due to left ventricle dysfunction (with no organic mitral valve disease) who underwent transthoracic echocardiography between January 2012 and March 2021 at our institution. The concomitant presence of severe left atrial (LA) dilation (>48 mL/m²) defined SADMR (SAD in SMR), and these patients were compared with those without SAD.

Results

A total of 2011 patients were included (mean age 70% and 41% females), with 71% having SADMR. MR severity and ejection fraction were similar between both groups. Patients with SADMR were older, less females and had more diabetes, but similar rates of atrial fibrillation. Mechanistically, they had lower A wave velocity (0.61 vs 0.72 cm/sec, p<0.001) and more impaired LA reservoir strain (9.7% vs 15.5%, p<0.001). Geometrically, SADMR had shallower leaflets’ angulations, lower tenting height, larger annuli and smaller leaflet length/annular diameter ratios (all p<0.001). They underwent fewer MV interventions, although these were associated with better outcomes (log-rank p<0.001). Over the study period, SAD was an independent predictor of mortality (HR 1.26, p=0.04).

Conclusion

SADMR is associated with specific mechanistic and functional alterations and confers a worse prognosis.

Progression of Mitral Regurgitation in Rheumatic Valve Disease: Role of Left Atrial Remodeling

Introduction

Mitral regurgitation (MR) is the most common valve abnormality in rheumatic heart disease (RHD) often associated with stenosis. Although the mechanism by which MR develops in RHD is primary, longstanding volume overload with left atrial (LA) remodeling may trigger the development of secondary MR, which can impact on the overall progression of MR. This study is aimed to assess the incidence and predictors of MR progression in patients with RHD.

Methods

Consecutive RHD patients with non-severe MR associated with any degree of mitral stenosis were selected. The primary endpoint was a progression of MR, which was defined as an increase of one grade in MR severity from baseline to the last follow-up echocardiogram. The risk of MR progression was estimated accounting for competing risks.

Results

The study included 539 patients, age of 46.2 ± 12 years and 83% were women. At a mean follow-up time of 4.2 years (interquartile range [IQR]: 1.2–6.9 years), 54 patients (10%) displayed MR progression with an overall incidence of 2.4 per 100 patient-years. Predictors of MR progression by the Cox model were age (adjusted hazard ratio [HR] 1.541, 95% CI 1.222–1.944), and LA volume (HR 1.137, 95% CI 1.054–1.226). By considering competing risk analysis, the direction of the association was similar for the rate (Cox model) and incidence (Fine-Gray model) of MR progression. In the model with LA volume, atrial fibrillation (AF) was no longer a predictor of MR progression. In the subgroup of patients in sinus rhythm, 59 had an onset of AF during follow-up, which was associated with progression of MR (HR 2.682; 95% CI 1.133–6.350).

Conclusions

In RHD patients with a full spectrum of MR severity, progression of MR occurs over time is predicted by age and LA volume. LA enlargement may play a role in the link between primary MR and secondary MR in patients with RHD.

Variable definitions and treatment approaches for atrial functional mitral regurgitation: A scoping review of the literature

OBJECTIVES

Atrial functional mitral regurgitation (AFMR) is a subtype of functional mitral regurgitation due to longstanding atrial fibrillation (AF) or heart failure with preserved ejection fraction. The variation in AFMR' definition and the common mode of treatment described in the literature remain unknown.

METHODS

We performed a scoping review of studies that surgically treated AFMR to characterize the existing variability in the definition of AFMR, the type of operations performed for AFMR valvulopathy, and the treatment for the chronic AF. We searched Medline, EMBASE, Cochrane Library, Scopus, and Web of Science since their inceptions for studies of patients affected by AFMR and surgically treated for their valvulopathy.

RESULTS

Twelve studies (n = 494 patients) met eligibility criteria. All studies excluded patients with signs of left ventricular (LV) dysfunction, but the way additional parameters were used to define AFMR at a more granular level varied across studies: nine studies (75%) used the presence of AF to define their AFMR cohorts, with five (41.2%) requiring a history of AF of >1 year; additionally, the threshold values for the LV ejection fraction differed (45%-55%). Isolated mitral annuloplasty was performed in 96.2% of patients. Broad variability was detected in the proportion of patients undergoing the Cox-Maze procedure (range, 17.8%-79.5%), pulmonary vein isolation (0.0%-66.7%), and left atrial appendage ligation (0.0%-100.0%).

CONCLUSIONS

AFMR remains variably defined in surgical studies, making comparisons across studies difficult. Mitral annuloplasty was most commonly performed. The proportion of AFMR patients undergoing concomitant procedures for AF varied substantially.

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.

Effect of catheter ablation on clinical outcomes in patients with atrial fibrillation and significant functional mitral regurgitation

Background

In patients with atrial fibrillation (AF) and functional mitral regurgitation (MR), catheter ablation reduces the severity of MR and improves cardiac remodeling. However, its effects on prognosis are uncertain.

Methods

This retrospective study included 151 consecutive patients with AF and functional MR, 82 (54.3%) of whom were treated by catheter ablation (Ablation group) and 69 (45.7%) with drug therapy without ablation (Non-ablation group). Forty-three pairs of these patients were propensity matched on the basis of age, CHA₂DS₂-VASc scores, and left ventricular ejection fraction. The primary outcome evaluated was severity of MR, cardiac remodeling and the combined incidence of subsequent heart failure-related hospitalization and strokes/transient ischemic attacks.

Results

Patients in the Ablation group showed a significant decrease in the severity of MR (p < 0.001), a significant decrease in the left atrial diameter (p = 0.010), and significant improvement in the left ventricular ejection fraction (p = 0.015). However, patients in the Non-ablation group showed only a significant decrease in the severity of MR (p = 0.004). The annual incidence of the studied events was 4.9% in the Ablation group and 16.7% in the Non-ablation group, the incidence being significantly lower in the ablation than Non-ablation group (p = 0.026) according to Kaplan–Meier curve analyses. According to multivariate Cox regression analysis, catheter ablation therapy (hazard ratio [HR] 0.27, 95% confidence interval [CI] 0.09–0.84; p = 0.024) and heart failure at baseline (HR 3.84, 95% CI 1.07–13.74; p = 0.038) were independent predictors of the incidence of the studied events.

Conclusions

Among patients with AF and functional MR, catheter ablation was associated with a significantly lower combined risk of heart failure-related hospitalization and stroke than in a matched cohort of patients receiving drug therapy alone.

Prevalence and factors associated with atrial mitral and tricuspid regurgitation in patients with atrial fibrillation

BACKGROUND

This study aimed to examine the prevalence of atrial tricuspid regurgitation (ATR) and atrial mitral regurgitation (AMR) in the setting of atrial fibrillation (AFib) and identify variables related to the severity of both types of regurgitation.

METHODS

Cross-sectional study evaluating data from transthoracic echocardiograms performed during 2019. We included patients with AFib during the examination, and without primary valve disease or other significant heart disease.

RESULTS

Four-hundred and thirty-two patients fulfilled the inclusion criteria (mean age 77.5±9.2 years, 49.1% women). We observed significant ATR in 14.8%, and significant AMR in 1.4% of patients. ATR and AMR severities were equal in 49.3% of patients, and 41% displayed greater ATR severity. ATR prevalence was significantly greater among women (23.1% vs 6.8%, p < 0.001), but AMR prevalence was similar between genders (1.9% vs .9%, p = 0.443). Variables related to greater ATR severity were: female sex (OR: 2.61, 95%CI: 1.60-4.24), left atrial (LA) volume (OR: 3.58, 95%CI: 1.50-8.55), systolic pulmonary artery pressure (OR: 1.10, 95%CI: 1.07-1.13), and moderate AMR (OR: 2.21, 95%CI: 1.22-4.00). Variables related to greater AMR severity were female sex (OR: 1.96, 95%CI: 1.24-3.09), LA volume (OR: 11.68, 95%CI: 5.29-25.80), and body mass index (OR: .94, 95%CI: .90-.98).

CONCLUSIONS

In the context of AFib, ATR was more prevalent than AMR and prevailed in women. LA enlargement was associated with higher degrees of both AMR and ATR. Pulmonary hypertension was also independently associated with ATR, as well as greater AMR severity, suggesting possible adaptive changes in leaflets that might modify the atrial regurgitation incidence.

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

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

Mitral valve regurgitation is associated with left atrial fibrosis in patients with atrial fibrillation

BACKGROUND

Low voltage zones (LVZ) are associated with poor outcomes in patients with atrial fibrillation (AF). The APPLE and DR-FLASH scores predict LVZ in patients undergoing catheter ablation. This study aimed to assess the relationship of mitral valve regurgitation (MR) and LVZ after adjusting for APPLE or DR-FLASH scores.

METHODS

This was a retrospective study on patients with AF who underwent their first catheter ablation. All patients underwent a transthoracic echocardiographic examination before ablation. The APPLE and DR-FLASH scores were calculated at baseline. LVZ determined by high-density mapping was defined as bipolar voltage amplitude <0.5 mV. LVZ presence was defined as LVZ covering >5% of the left atrial surface area.

RESULTS

Altogether, 152 patients (mean age 62.0 ± 10.8 years, 65.8% men, and 36.2% with persistent AF) were included. Of the 152 patients, 47 (30.9%) had LVZ. The patients with LVZ had more moderate-to-severe MR (17.0% vs. 3.8%, P = 0.014) and higher APPLE scores (1.7 ± 1.1 vs. 1.2 ± 1.1, P = 0.009) and DR-FLASH scores (3.0 ± 1.5 vs. 2.4 ± 1.4, P = 0.010). Using multivariate logistic regression analysis, we found moderate-to-severe MR was related to LVZ presence after adjusting for the APPLE (OR 4.040, P = 0.034) or DR-FLASH (OR 4.487, P = 0.020) scores. Furthermore, moderate-to-severe MR had an incremental predictive value for LVZ presence in addition to the APPLE (P = 0.03) or DR-FLASH (P = 0.02) scores.

CONCLUSION

In patients with AF, MR severity was related to LVZ after adjusting the APPLE score or DR-FLASH score.

Transcatheter edge-to-edge mitral valve repair in atrial functional mitral regurgitation: insights from the multi-center MITRA-TUNE registry

BACKGROUND

A-FMR is considered a specific sub-type of secondary MR in patients with atrial fibrillation (AF) and preserved left ventricle ejection fraction (LVEF). Aim of the study was to investigate the acute and mid-term outcomes of transcatheter edge-to-edge mitral valve repair (TMVr) with the MitraClip in atrial functional mitral regurgitation (A-FMR).

METHODS

The study included patients with A-FMR and concomitant AF who underwent to the MitraClip at 7 Italian Centers. Aim of the study was to assess the safety, efficacy and mid-term cardiovascular outcomes.

RESULTS

After reviewing 1153 patients with FMR treated with TMVr from 2009 to 2021, 87 patients (median age 81 years, 61% female) with A-FMR were identified. Technical success was achieved in 97%, 30-day device success in 83% and 30-day procedural success in 80%. All-cause death at 30-day was 5%. Estimated two-year freedom from all-cause death and cardiac death was 60% and 77%, respectively, whereas freedom from all-cause death/heart failure hospitalization was 55%. Residual MR ≤ 2+ was encountered in 89% (n = 47/53) and improvement in NYHA class I/II in 79% (n = 48/61). Post-procedural MR ≥ 2+ (HR 5.400, CI 1.371-21.268) and inter-commissural annular diameter ≥ 35 mm (HR 4.159, CI 1.057-16.363) were independent predictors of all-cause death/heart failure hospitalization during the follow-up. Positive reverse remodeling of left atrium and mitral annular dimensions occurred after TMVr during the follow-up.

CONCLUSIONS

MitraClip resulted to be a safe and effective option to treat A-FMR in elderly patients.

[A 19-year-old woman with palpitations and mitral regurgitation]

A young woman presented with palpitations. Holter monitoring revealed frequent premature ventricular complexes; echocardiography showed high-degree mitral regurgitation due to mitral valve prolapse. While mitral valve replacement or repair were being discussed, a different therapy was applied after further diagnostic work-up of the patient which in retrospect appears even more efficient.

Imaging of the left atrium: pathophysiology insights and clinical utility

Left atrial imaging and detailed knowledge of its pathophysiology, especially in the context of heart failure, have become an increasingly important clinical and research focus. This development has been accelerated by the growth of non-invasive imaging modalities, advanced image processing techniques, such as strain imaging, and the parallel emergence of catheter-based left atrial interventions like pulmonary vein ablation, left atrial appendage occlusion, and others. In this review, we focus on novel imaging methods for the left atrium, their pathophysiological background, and their clinical relevance for various cardiac conditions and diseases.

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.