Atrial Functional Mitral Regurgitation

The hybrid (physical-computational) cardiovascular simulator to study valvular diseases

To better understand the impact of valvular heart disease (VHD) on the hemodynamics of the circulatory system, investigations can be carried out using a model of the cardiovascular system. In this study, a previously developed hybrid (hydro-numerical) simulator of the cardiovascular system (HCS) was adapted and used. In our HCS Björk-Shiley mechanical heart valves were used, playing the role of mitral and aortic ones. In order to simulate aortic stenosis (AS) and mitral regurgitation (MR), special mechanical devices have been developed and integrated with the HCS. The simulation results proved that the system works correctly. Namely, in the case of AS - the mean pulmonary arterial pressure was increased due to increased preload of the left ventricle and the decrease in right ventricular preload was caused by a decrease in systemic arterial pressure. The severity of AS was performed based on the transaortic pressure gradient as well as using the Gorlin and Aaslid equations. In the case of severe AS, when the mean gradient was above 40 mmHg, the aortic valve orifice area was 0.5 cm2, which is in line with ACC/AHA guidelines. For the case of MR - with increasing severity of MR, there was a decrease in the left ventricular pressure and an increase in left atrial pressure. Using mechanical heart valves to simulate VHD by the HCS can be a valuable tool for biomedical research, providing a safe and controlled environment to study and understand the pathophysiology of VHD.

Tricuspid Regurgitation and Right Heart Failure: The Role of Imaging in Defining Pathophysiology, Presentation, and Novel Management Strategies

During the last few years, there has been a substantial shift in efforts to understand and manage secondary or functional tricuspid regurgitation (TR) given its prevalence, adverse prognostic impact, and symptom burden associated with progressive right heart failure. Understanding the pathophysiology of TR and right heart failure is crucial for determining the best treatment strategy and improving outcomes. In this article, we review the complex relationship between right heart structural and hemodynamic changes that drive the pathophysiology of secondary TR and discuss the role of multimodality imaging in the diagnosis, management, and determination of outcomes.

Tricuspid Regurgitation and Right Heart Failure: The Role of Imaging in Defining Pathophysiology, Presentation, and Novel Management Strategies

During the last few years, there has been a substantial shift in efforts to understand and manage secondary or functional tricuspid regurgitation (TR) given its prevalence, adverse prognostic impact, and symptom burden associated with progressive right heart failure. Understanding the pathophysiology of TR and right heart failure is crucial for determining the best treatment strategy and improving outcomes. In this article, we review the complex relationship between right heart structural and hemodynamic changes that drive the pathophysiology of secondary TR and discuss the role of multimodality imaging in the diagnosis, management, and determination of outcomes.

Transcatheter mitral and tricuspid interventions-the bigger picture: valvular disease as part of heart failure

The prevalence of mitral (MR) and tricuspid regurgitation (TR), especially in heart failure (HF) populations, is high. However, the distinct role of atrioventricular valve diseases in HF, whether they are merely indicators of disease status or rather independent contributors in a vicious disease cycle, is still not fully understood. For decades, tricuspid regurgitation (TR) was considered an innocent bystander subsequent to other heart or lung pathologies, thus, not needing dedicated treatment. Recent increasing awareness towards the role of atrioventricular valve diseases has revealed that MR and TR are, in fact, independent predictors of outcome in HF, thus, warranting attention in the HF treatment algorithm. This awareness arose, especially, with the development of minimally invasive transcatheter solutions providing new treatment options, which can also be used for patients considered as having increased surgical risk. However, outcomes of such transcatheter treatments have, in part, been sub-optimal and likely influenced by the status of the concomitant HF disease. Thus, this review aims to summarize data on the current understanding regarding the role of MR and TR in HF, how HF impacts outcomes of transcatheter MR and TR interventions, and how the understanding of this relationship might help to identify patients that benefit most from these therapies, which have proven to be lifesaving in properly selected candidates.

Atrial functional mitral regurgitation: prevalence, characteristics and outcomes from the National Echo Database of Australia

AIMS

Atrial functional mitral regurgitation (AFMR) is characterised by left atrial and consequent mitral annular dilatation causing mitral regurgitation. AFMR is likely to become more common with population ageing, alongside increases in atrial fibrillation and heart failure with preserved ejection fraction; conditions causing atrial dilatation. Here, we aim to define the prevalence and characterise the patient and survival characteristics of AFMR in the National Echocardiographic Database of Australia (NEDA).

METHODS AND RESULTS

14 004 adults with moderate or severe FMR were identified from NEDA. AFMR or ventricular FMR (VFMR) was classified by LA size, LV size and LVEF. AFMR was found in 40% (n=5562) and VFMR in 60% (n=8442). Compared with VFMR, the AFMR subgroup were significantly older (mean age 78±11 years), with a higher proportion of females and of AF. Participants were followed up for a median of 65 months (IQR 36-116 months). After adjustment for age, sex, AF, and pulmonary hypertension, the prognosis for VFMR was significantly worse than for AFMR (HR 1.57, 95% CI 1.47 to 1.68 for all-cause and 1.73, 95% CI 1.60 to 1.88, p<0.001 for both). After further adjustment for LVEF, mortality rates were similar in VFMR and AFMR patients (HR 0.93, p=NS), though advancing age and pulmonary hypertension remained independently associated with prognosis.

CONCLUSIONS

AFMR is a common cause of significant functional MR that predominantly affects elderly female patients with AF. Advancing age and pulmonary hypertension independently associated with survival in FMR. Prognosis was better in AFMR compared with VFMR; however, this difference was accounted for by LV systolic impairment and not by MR severity.

Sacubitril/Valsartan Cannot Improve Cardiac Function Compared with Valsartan in Patients Suffering Nonvalvular Atrial Fibrillation without Systolic Heart Failure

This study investigates the effect of sacubitril/valsartan (Sac/Val) in patients diagnosed with nonvalvular atrial fibrillation (AF) without systolic heart failure (SHF).Nonvalvular AF patients without SHF admitted to the People's Hospital of Bortala Mongol Autonomous Prefecture from December 2020 to December 2021 were enrolled and randomly divided into Sac/Val treatment group (group T) and valsartan treatment group (group C, control). For subgroup analysis, patients were divided into subgroups with and without diastolic heart failure (DHF). After 1-month adaptive phase and subsequent 3-month treatment period, patients were followed up in the cardiology clinic. Plasma levels of biochemical markers and echocardiographic parameters before and after treatment were evaluated, and DHF scores were computed to assess diastolic function.Of 61 enrolled patients, 46 patients completed follow-up. Sac/Val treatment did not increase the percentage of sinus rhythm. Although N-terminal pro-B-type natriuretic peptide (NT-proBNP) expression tended to be reduced in both groups after 3 months of treatment, the differences compared with respective baseline levels and between groups were not significant. According to subgroup analysis, although NT-proBNP expression in the subgroup with DHF was lower at follow-up compared to baseline, the difference was not statistically significant. Similarly, no marked differences in echocardiographic parameters or tissue Doppler parameters related to DHF were detected between the groups (P > 0.05). Additionally, a subgroup analysis found no significant variations in the echocardiographic measures (P > 0.05).Sac/Val is not superior to valsartan for the short-term treatment of patients suffering with AF without SHF in improving NT-proBNP level and cardiac function.

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.

Impact of secondary mitral regurgitation on survival in atrial and ventricular dysfunction

BACKGROUND

Natural history of atrial and ventricular secondary mitral regurgitation (SMR) is poorly understood. We compared the impact of the degree of SMR on survival between atrial and ventricular dysfunction.

METHODS

We conducted a retrospective cohort study of patients who underwent echocardiography in a healthcare network between 2013-2018. We compared the survival of patients with atrial and ventricular dysfunction, using propensity scores developed from differences in patient demographics and comorbidities within SMR severity strata (none, mild, moderate or severe). We fitted Cox proportional hazards models to estimate the risk-adjusted hazards of death across different severities of SMR between patients with atrial and ventricular dysfunction.

RESULTS

Of 11,987 patients included (median age 69 years [IQR 58-80]; 46% women), 6,254 (52%) had isolated atrial dysfunction, and 5,733 (48%) had ventricular dysfunction. 3,522 patients were matched from each arm using coarsened exact matching. Hazard of death in atrial dysfunction without SMR was comparable to ventricular dysfunction without SMR (HR 1.1, 95% CI 0.9-1.3). Using ventricular dysfunction without SMR as reference, hazards of death remained higher in ventricular dysfunction than in atrial dysfunction across increasing severities of SMR: mild SMR (HR 2.1, 95% CI 1.8-2.4 in ventricular dysfunction versus HR 1.7, 95%CI 1.5-2.0 in atrial dysfunction) and moderate/severe SMR (HR 2.8, 95%CI 2.4-3.4 versus HR 2.4, 95%CI 2.0-2.9).

CONCLUSIONS

SMR across all severities were associated with better survival in atrial dysfunction than in ventricular dysfunction, though the magnitude of the diminishing survival were similar between atrial and ventricular dysfunction in increasing severity of SMRs.

Prognostic Impact of Severe Atrial Functional Tricuspid Regurgitation in Atrial Fibrillation Patients

Background and Aim: Atrial fibrillation (AF) is an epidemic disease with a significant global health impact. Atrial functional tricuspid regurgitation (AF-TR) is a more recently acknowledged complication of AF. The main purpose of this study was to determine the prognostic value of severe AF-TR in patients with AF, and its determinants. Methods: In this retrospective, observational study, we included AF patients admitted consecutively to a tertiary clinical hospital between January 2018 and February 2020, irrespective of cause of hospitalization. Patients with organic TR, significant pulmonary hypertension, left ventricular ejection fraction < 50%, those with implanted cardiac devices and those with in-hospital mortality were excluded. Severe TR was defined according to current guidelines. Median follow-up time was 34 (28−39) months. Primary endpoint was all-cause mortality. Results: We included 246 AF patients, with a mean age of 71.5 ± 9.4 years. 86.2% had AF-TR, while 8.1% had severe AF-TR. Mortality rate was 8.5%. Right atrial diameter (p = 0.005), systolic pulmonary artery pressure (sPAP) (p = 0.015) and NT-proBNP (p = 0.026) were independent predictors for the presence of severe valvular dysfunction. In multivariable survival analysis, severe AF-TR, was an independent predictor of all-cause mortality (HR 5.4, 95% CI 1.1−26.2, p = 0.035). Conclusion: Severe AF-TR was an independent predictor of mortality in AF patients, while mild/moderate AF-TR apparently had no impact on prognosis.

Atrial Functional Tricuspid Regurgitation: Novel Definition and Impact on Prognosis

BACKGROUND

Atrial functional tricuspid regurgitation (atrial TR) has received growing recognition as a TR entity with a distinct cause owing to its independence from valvular tethering as the predominant mechanism underlying TR. However, characterization of atrial TR varies, and a universal definition is lacking.

METHODS

In total, 651 patients with significant functional TR were analyzed, including 438 conservatively treated individuals and 213 patients who received transcatheter tricuspid valve repair (TTVR). Based on a clustering approach, we defined atrial TR as tricuspid valve (TV) tenting height ≤10 mm, midventricular right ventricular diameter ≤38 mm, and left ventricular ejection fraction ≥50%.

RESULTS

Patients with atrial TR were more often females, had higher right ventricular fractional area change, higher left ventricular ejection fraction, and lower LV end-diastolic diameter, TV tenting area and height, lower right ventricular and tricuspid annular size, enlarged, but lower right atrial area and lower TV effective regurgitant orifice area (all P<0.05). Patients with atrial TR had significantly better long-term survival than non-atrial TR in the conservatively treated TR cohort (P<0.01, n=438). Atrial TR was independently associated with a lower rate of the combined end point of mortality and heart failure hospitalization at 1-year follow-up in the TTVR cohort (hazard ratio, 0.39; P<0.05, n=213). TR degree was significantly reduced after TTVR in non-atrial and atrial TR (P<0.01). Functional parameters significantly improved following TTVR independent of TR cause (P<0.05).

CONCLUSIONS

An echocardiography-based atrial TR definition is associated with prognostic relevance in patients with functional TR in conservatively treated TR and after TTVR.

Device Therapy in Chronic Heart Failure: JACC State-of-the-Art Review

The regulatory landscape for device-based heart failure (HF) therapies has seen a major shift in the last 7 years. In 2013, the U.S. Food and Drug Administration released guidance for early feasibility and first-in-human studies, thereby encouraging device innovation, and in 2016 the U.S. Congress authorized the Breakthrough Devices Program to expedite access for Americans to innovative devices indicated for diagnosis and treatment of serious illnesses, such as HF. Since December 2016, there has been an increase in the number of HF devices for which manufacturers are seeking approval through the breakthrough designation pathway. This has led to a rapid uptake in the development and evaluation of device-based HF therapies. This article reviews the current and future landscape of device therapies for chronic HF and associated comorbidities and the regulatory environment that is driving current and future innovation.

Update on management of atrial fibrillation in heart failure: a focus on ablation

Atrial fibrillation is increasingly encountered in patients with heart failure. Both diseases have seen tremendous rises in incidence in recent years. In general, the treatment of atrial fibrillation is focused on relieving patients from atrial fibrillation-related symptoms and risk reduction for thromboembolism and the occurrence or worsening of heart failure. Symptomatic relief may be accomplished by either (non-)pharmacological rate or rhythm control in combination with optimal therapy of underlying cardiovascular morbidities and risk factors. Atrial fibrillation ablation has been performed in patients without overt heart failure successfully for many years. However, in recent years, attempts have been made for patients with heart failure as well. In this review, we discuss the current literature describing the treatment of atrial fibrillation in heart failure. We highlight the early rate versus rhythm control studies, the importance of addressing underlying conditions and treatment of risk factors. A critical evaluation will be performed of the catheter ablation studies that have been performed so far in light of larger (post-hoc) ablation studies. Furthermore, we will hypothesise the role of patient selection as next step in optimising outcome for patient with atrial fibrillation and heart failure.

Mitral valve repair and surgical ablation for atrial functional mitral regurgitation

Background

This observational study aimed to share our experience in the surgical management of atrial functional mitral regurgitation (AFMR).

Methods

We retrospectively identified 82 AFMR patients (63.6±7.7 years) from June 2008 to November 2018 at our institution. Of these patients, 72.0% of them were classified as NYHA functional class III/IV, and all of them had persistent AF. All patients underwent mitral valve (MV) repair, and 52 (63.4%) received concomitant surgical ablation (SA). Patients were followed up for 26.1±27.6 months, and postoperative mitral regurgitation (MR) was assessed by echocardiography.

Results

There was no in-hospital mortality. The overall 1-year and 3-year survival rates were 97.5% and 92.9%, respectively, and 96.1% of patients recovered to NYHA functional class I/II at the latest follow-up. The left atrium (LA) diameter (P<0.001), left ventricular (LV) end-diastolic diameter (P<0.001), LV end-systolic diameter (LVESD) (P<0.001) and pulmonary artery pressure (P=0.006) significantly decreased postoperatively. The overall 1-year and 3-year freedom from recurrent MR rates were 94.3% and 65.3%, respectively, and a significant difference was found between the SA group and the non-SA group (93.8% and 93.8% vs. 95.5% and 44.2%, P=0.035). In a subgroup analysis, this significant difference was only found in the small LA group (≤60 mm).

Conclusions

Our results suggest that MV repair for AFMR is safe and effective. It improves heart failure symptoms and results in reverse-remodeling of both the LA and LV. Concomitant SA might benefit patients in terms of recurrent MR, especially in the small LA group (≤60 mm).

Causes and mechanisms of isolated mitral regurgitation in the community: clinical context and outcome

AIMS

To define the hitherto unknown aetiology/mechanism distributions of mitral regurgitation (MR) in the community and the linked clinical characteristics/outcomes.

METHODS AND RESULTS

We identified all isolated, moderate/severe MR diagnosed in our community (Olmsted County, MN, USA) between 2000 and 2010 and classified MR aetiology/mechanisms. Eligible patients (n = 727) were 73 ± 18 years, 51% females, with ejection fraction (EF) 49 ± 17%. MR was functional (FMR) in 65%, organic (OMR) in 32% and 2% mixed. Functional MR was linked to left ventricular remodelling (FMR-v) 38% and isolated atrial dilatation (FMR-a) 27%. At diagnosis FMR-v vs. FMR-a, vs. OMR displayed profound differences (all P < 0.0001) in age (73 ± 14, 80 ± 10, 68 ± 21years), male-sex (59, 33, 51%), atrial-fibrillation (28, 54, 13%), EF (33 ± 14, 57 ± 11, 61 ± 10%), and regurgitant-volume (38 ± 13, 37 ± 11, 51 ± 24 mL/beat). Dominant MR mechanism was Type I (normal valve-movement) 38%, Type II (excessive valve-movement) 25%, Type IIIa (diastolic movement-restriction) 3%, and Type IIIb (systolic movement-restriction) 34%. Outcomes were mediocre with excess-mortality vs. general-population in FMR-v [risk ratio 3.45 (2.98-3.99), P < 0.0001] but also FMR-a [risk ratio 1.88 (1.52-2.25), P < 0.0001] and OMR [risk ratio 1.83 (1.50-2.22), P < 0.0001]. Heart failure was frequent, particularly in FMR-v (5-year 83 ± 3% vs. 59 ± 4% FMR-a, 40 ± 3% OMR, P < 0.0001). Mitral surgery during patients' lifetime was performed in 4% of FMR-v, 3% of FMR-a, and 37% of OMR.

CONCLUSION

Moderate/severe isolated MR in the community displays considerable aetiology/mechanism heterogeneity. Functional MR dominates, mostly FMR-v but FMR-a is frequent and degenerative MR dominates OMR. Outcomes are mediocre with excess-mortality particularly with FMR-v but FMR-a, despite normal EF incurs notable excess-mortality and frequent heart failure. Pervasive undertreatment warrants clinical trials of therapies tailored to specific MR cause/mechanisms.

Outcomes with percutaneous mitral repair vs. optimal medical treatment for functional mitral regurgitation: systematic review

Functional mitral regurgitation (MR) could be defined as a ventricular disease where mitral valve is structurally normal, left chambers are enlarged and mitral annulus is dilated with lack of coaptation of leaflets. Transcatheter mitral valve repair technique has broadened the therapeutic range in the treatment of severe MR. The aim of this study was to review outcomes of MitraClip vs. medical treatment for functional MR. We also planned to review the concept of functional MR, assessment of the degree, prognosis and therapy options. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The Medline through PubMed database was used to search. The present review included manuscripts published between January 2009 and September 2019. Two authors independently screened titles and abstracts of all publications, and performed the selection of studies and data extraction. In the case of disagreements, consensus meetings reached the final decision. Inclusion criteria were: (I) randomized controlled trials and (II) works must compare MitraClip versus optimal medical treatment. Transcatheter mitral valve repair along optimal medical treatment has been compared with optimal medical therapy in two different randomized trials. In the COAPT trial, the MitraClip group showed a significant reduction in mortality and heart failure (HF) hospitalizations. In the MITRA-FR trial, no significant differences were observed between both groups. We reviewed important aspects of functional MR and performed a comprehensive review of both trials comparing them and focusing on their differences.

Decreased Mortality with Beta-Blocker Therapy in HFpEF Patients Associated with Atrial Fibrillation

Background

There are no proven effective treatments that can reduce the mortality in heart failure with preserved ejection fraction (HFpEF), probably due to its heterogeneous nature which will weaken the effect of therapy in clinical studies. We evaluated the effect of beta-blocker treatment in HFpEF patients associated with atrial fibrillation (AF), which is a homogeneous syndrome and has seldom been discussed.

Methods

This retrospective cohort study screened 955 patients diagnosed with AF and HFpEF. Patients with a range of underlying heart diseases or severe comorbidities were excluded; 191 patients were included and classified as with or without beta-blocker treatment at baseline. The primary outcome was all-cause mortality and rehospitalization due to heart failure. Kaplan-Meier curves and multivariable Cox proportional-hazards models were used to evaluate the differences in outcomes.

Results

The mean follow-up was 49 months. After adjustment for multiple clinical risk factors and biomarkers for prognosis in heart failure, patients with beta-blocker treatment were associated with significantly lower all-cause mortality (hazard ratio (HR) = 0.405, 95% confidence interval (CI) = 0.233–0.701, p=0.001) compared with those without beta-blocker treatment. However, the risk of rehospitalization due to heart failure was increased in the beta-blocker treatment group (HR = 1.740, 95% CI = 1.085–2.789, p=0.022). There was no significant difference in all-cause rehospitalization between the two groups (HR = 1.137, 95% CI = 0.803–1.610, p=0.470).

Conclusions

In HFpEF patients associated with AF, beta-blocker treatment is associated with significantly lower all-cause mortality, but it increased the risk of rehospitalization due to heart failure.

Secondary mitral regurgitation: pathophysiology, proportionality and prognosis

Secondary mitral regurgitation (SMR) occurs as a result of multifactorial left atrioventricular dysfunction and maleficent remodelling. It is the most common and undertreated form of mitral regurgitation (MR) and is associated with a very poor prognosis. Whether SMR is a bystander reflecting the severity of the cardiomyopathy disease process has long been the subject of debate. Studies suggest that SMR is an independent driver of prognosis in patients with an intermediate heart failure (HF) phenotype and not those with advanced HF. There is also no universal agreement regarding the quantitative thresholds defining severe SMR and indeed there are challenges with echocardiographic quantification. Until recently, no surgical or transcatheter intervention for SMR had demonstrated prognostic benefit, in contrast with HF medical therapy and cardiac resynchronisation therapy. In 2018, the first two randomised controlled trials (RCTs) of edge-to-edge transcatheter mitral valve repair versus guideline-directed medical therapy in HF (Percutaneous Repair with the MitraClip Device for Severe (MITRA-FR), Transcather mitral valve repair in patients with heart failure (COAPT)) reported contrasting yet complimentary results. Unlike in MITRA-FR, COAPT demonstrated significant prognostic benefit, largely attributed to the selection of patients with disproportionately severe MR relative to their HF phenotype. Consequently, quantifying the degree of SMR in relation to left ventricular volume may be a useful discriminator in predicting the success of transcatheter intervention. The challenge going forward is the identification and validation of such parameters while in parallel maintaining a heart-team guided holistic approach.

Left ventricular extracellular volume expansion does not predict recurrence of atrial fibrillation following catheter ablation

INTRODUCTION

A recent study reported that diffuse left ventricular (LV) fibrosis is a predictor of atrial fibrillation (AF) recurrence following catheter ablation, by measuring postcontrast cardiac T1 (an error prone metric as per the 2017 Society for Cardiovascular Magnetic Resonance consensus statement) using an inversion-recovery pulse sequence (an error prone method in arrhythmia) in AF ablation candidates. The purpose of this study was to verify the prior study, by measuring extracellular volume (ECV) fraction (an accurate metric) using a saturation-recovery pulse sequence (accurate method in arrhythmia).

METHODS AND RESULTS

This study examined 100 AF patients (mean age = 62 ± 11 years, 69 males and 31 females, 67 paroxysmal [pAF] and 33 persistent [peAF]) who underwent a preablation cardiovascular magnetic resonance (CMR) exam. LV ECV and left atrial (LA) and LV functional parameters were quantified using standard analysis methods. During an average follow-up period of 457 ± 261 days with 4 ± 3 rhythm checks per patient, 72 patients maintained sinus rhythm. Between those who maintained sinus rhythm (n = 72) and those who reverted to AF (n = 28), the only clinical characteristic that was significantly different was age (60 ± 12 years vs 66 ± 9 years); for CMR metrics, neither mean LV ECV (25.1 ± 3.3% vs 24.7 ± 3.7%), native LV T1 (1093.8 ± 73.5 ms vs 1070.2 ± 115.9 ms), left ventricular ejection fraction (54.1 ± 11.2% vs 55.7 ± 7.1%), nor LA end diastolic volume/body surface area (42.4 ± 14.8 mL/m2 vs 43.4 ± 19.6 mL/m2 ) were significantly different (P ≥ .23). According to Cox regression tests, none of the clinical and imaging variables predict AF recurrence.

CONCLUSION

Neither LV ECV nor other CMR metrics predict recurrence of AF following catheter ablation.

Roles of Transesophageal Echocardiography and Cardiac Computed Tomography for Evaluation of Left Atrial Thrombus and Associated Pathology: A Review and Critical Analysis

Evaluation of the left atrium and left atrial appendage for the presence of thrombus prior to cardioversion and pulmonary vein isolation, and of the entire heart for embolic sources in the setting of cryptogenic stroke, has long been standard medical care. Guidelines have uniformly recommended transesophageal echocardiography (TEE) to accomplish these goals. In recent years, computed tomographic angiography has demonstrated diagnostic accuracy similar to that of TEE for the detection of thrombus. Analysis of the pertinent data and relative merits of the 2 technologies leads to the conclusions that: 1) both modalities have some unique, nonoverlapping capabilities that may dictate their use in specific situations; 2) computed tomographic angiography is a reasonable alternative to TEE when the primary aim is to exclude left atrial and left atrial appendage thrombus and in patients in whom the risks associated with TEE outweigh the benefits; and 3) both options should be discussed with the patient in the setting of shared decision making.

Long-term effect of atrial fibrillation on the evolution of mitral and tricuspid valve regurgitation

Objective: The present study aims to identify the long-term effects of atrial fibrillation (AF) on atrial remodelling and on the progression of mitral/tricuspid valve regurgitation (MR/TR). Methods: The severity of MR/TR was assessed by the colour jet area and by multi-integrative approach at baseline and after a period of 65 ± 10 months in 37 patients with permanent AF, in 80 patients with non-permanent AF (of whom 43 were treated with ablation) and in 53 control patients with sinus rhythm. Results: At baseline, AF patients had larger MR jet areas than control patients. At follow up, progression of MR, expressed as delta MR jet area, was 0.05 ± 1.3 cm² in the control group, 0.73 ± 2.1 cm² in the non-permanent AF group and 1.95 ± 3.6 cm² in the permanent AF group (p = .001). Severe MR at follow up was observed in 0%, 2.5%, 8%, respectively. There was a significant positive correlation between progression of MR and increase of left atrium volume (r = 0.31, p < .001). After adjustment for baseline clinical and echocardiographic parameters, permanent AF remained independently associated with the progression of MR. Although rhythm control was better with AF ablation than with medical treatment only, the MR evolution was similar. Comparable findings, albeit less pronounced, were observed for the association between of AF and TR progression. Conclusions: The presence of longstanding AF is associated with a significant progression of MR/TR mainly due to atrial remodelling. Our data showed a beneficial effect of sustained rhythm control, either medically or by ablation, on MR/TR progression.

[Cardioband®: Where do we stand, who are suitable patients?]

Functional mitral regurgitation (FMR) is characterized by a dilatation of the mitral valve annulus resulting in an insufficient adaptation of the anterior and posterior mitral valve leaflets and/or severe tethering of the leaflets due to dilatation of the left ventricle. The Cardioband® system was introduced in 2015 and is a catheter-based direct mitral valve annuloplasty procedure for treatment of FMR. In the European CE approval study 60 patients with moderate or severe FMR were analyzed per protocol. There were no device or procedure-related deaths. The technical success rate of the procedure, defined as successful implantation and tightening was 97%. At 1 year, the overall survival and survival free of hospital readmission for heart failure were 87% and 66%, respectively. Currently, various interventional treatment procedures are available, such as the edge-to-edge technique as well as direct and indirect annuloplasty. In summary, patients with FMR as a result of a dilatation of the mitral valve annulus appear to be suitable for direct annuloplasty with the Cardioband® system.

The characteristics of a porcine mitral regurgitation model

The porcine mitral regurgitation (MR) model is a common cardiovascular animal model. Standardized manufacturing processes can improve the uniformity and success rate of the model, and systematic research can evaluate its potential use. In this study, 17 pigs were divided into an experimental group (n=11) and a control group (n=6). We used a homemade retractor to cut the mitral chordae via the left atrial appendage to establish a model of MR; the control group underwent a sham surgery. The model animals were followed for 30 months after the surgery. Enlargement and fibrosis of the left atrium were significant in the experimental group compared with those in the control group, and left atrial systolic function decreased significantly. In addition, model animals showed preserved left ventricular systolic function. There were no differences in left atrial potential or left ventricular myocardial fibrosis between the two groups. Atrial fibrillation susceptibility in the experimental group was higher than that in the control group. Our method enables the simple and effective production of a MR model with severe reflux that can be used for pathophysiological studies of MR, as well as for the development of preclinical surgical instruments and their evaluation. This model could also be used to study atrial fibrillation and myocardial fibrosis but is not suitable for studies of heart failure.