Preoperative diagnostic value of multimodal spectral CT for patients with atrial fibrillation undergoing radiofrequency ablation

Objective

Delayed enhancement cardiac computed tomography (CT) empowers the diagnosis of left atrial appendage thrombus while limited to scanning heterogeneity. We optimized the spectral CT scan and post-process protocols, incorporating delayed enhancement and spectral iodine analysis to discriminate left atrial appendage (LAA) thrombus with better morphological relationships between the left atrium, pulmonary vein, and esophagus.

Methods

A total of 278 consecutive patients were retrieved from January 2019 to June 2023. All patients underwent transesophageal echocardiography (TEE) and spectral CT scan of the left atrial and pulmonary vein, with a complete period including the pulmonary venous phase and three delay phases. TEE diagnosis was used as the standard reference. For patients exhibiting LAA filling defects during the pulmonary venous phase, a delayed scan of 30 s (phase I) was performed. If the filling defects persisted, a further delayed scan of 1 min (phase II) was conducted. In cases where the filling defects persisted, an additional delayed scan of 2 min (phase III) was carried out. Iodine concentration in the filled defect area of LAA and the left atrium was measured in phase III. Moreover, 30 patients were randomly selected for water-swallowing and the other 30 for calm breathing. The image quality and esophageal dilation of the two groups were assessed by two experienced surgeons specializing in radiofrequency ablation.

Results

In total, 14 patients were diagnosed with thrombi by TEE. The sensitivity, specificity, positive predictive values, negative predictive values, and AUC of phase III delayed combined with iodine quantification for thrombi diagnosis were all 100%. The water-swallowing group exhibited significantly greater esophageal filling and expansion than the calm-breathing group, contributing to a better morphology assessment with no significant difference in image quality.

Conclusion

Combined with iodine quantification, delayed enhancement of spectral CT imaging presents a promising diagnostic potency for LAA thrombus. Incorporating water swallowing into the CT scan process further enables anatomical visualization of the esophagus, left atrium, and pulmonary vein, thereby providing more objective and authentic imaging evidence to assess the esophageal morphology and positional relationships.

Atrial cardiomyopathy revisited-evolution of a concept: a clinical consensus statement of the European Heart Rhythm Association (EHRA) of the ESC, the Heart Rhythm Society (HRS), the Asian Pacific Heart Rhythm Society (APHRS), and the Latin American Heart Rhythm Society (LAHRS)

AIMS

The concept of "atrial cardiomyopathy" (AtCM) had been percolating through the literature since its first mention in 1972. Since then, publications using the term were sporadic until the decision was made to convene an expert working group with representation from four multinational arrhythmia organizations to prepare a consensus document on atrial cardiomyopathy in 2016 (EHRA/HRS/APHRS/SOLAECE expert consensus on atrial cardiomyopathies: definition, characterization, and clinical implication). Subsequently, publications on AtCM have increased progressively.

METHODS AND RESULTS

The present consensus document elaborates the 2016 AtCM document further to implement a simple AtCM staging system (AtCM stages 1-3) by integrating biomarkers, atrial geometry, and electrophysiological changes. However, the proposed AtCM staging needs clinical validation. Importantly, it is clearly stated that the presence of AtCM might serve as a substrate for the development of atrial fibrillation (AF) and AF may accelerates AtCM substantially, but AtCM per se needs to be viewed as a separate entity.

CONCLUSION

Thus, the present document serves as a clinical consensus statement of the European Heart Rhythm Association (EHRA) of the ESC, the Heart Rhythm Society (HRS), the Asian Pacific Heart Rhythm Society (APHRS), and the Latin American Heart Rhythm Society (LAHRS) to contribute to the evolution of the AtCM concept.

Echocardiographic assessment of left atrial appendage morphology and function-an expert proposal by the German Working Group of Cardiovascular Ultrasound

The left atrial appendage is a blind ending cardiac structure prone to blood stasis due to its morphology. This structure is a preferred region of thrombogenesis in relation to reduced myocardial contractility of the atrial wall. Blood stasis occurs primarily in low flow conditions. One of the tasks of echocardiography is the analysis of morphology and function of the left atrial appendage. The detection of thrombi by echocardiography is difficult and must be carried out thoroughly and carefully to avoid potential complications-especially in the context of rhythm control. The assessment of thromboembolic risk, especially in patients with unknown and presumed atrial fibrillation is a second challenge by characterizing atrial function and flow conditions in the left atrial appendage. Thus, this proposal focuses on the obvious problems of echocardiography when assessing left atrial appendage and the role of this method in planning a potential interventional closure of left atrial appendage.

Echocardiographic assessment of atrial, ventricular, and valvular function in patients with atrial fibrillation-an expert proposal by the german working group of cardiovascular ultrasound

Echocardiography in patients with atrial fibrillation is challenging due to the varying heart rate. Thus, the topic of this expert proposal focuses on an obvious gap in the current recommendations about diagnosis and treatment of atrial fibrillation (AF)-the peculiarities and difficulties of echocardiographic imaging. The assessment of systolic and diastolic function-especially in combination with valvular heart diseases-by echocardiography can basically be done by averaging the results of echocardiographic measurements of the respective parameters or by the index beat approach, which uses a representative cardiac cycle for measurement. Therefore, a distinction must be made between the functionally relevant status, which is characterized by the averaging method, and the best possible hemodynamic status, which is achieved with the most optimal left ventricular (LV) filling according to the index beat method with longer previous RR intervals. This proposal focuses on left atrial and left ventricular function and deliberately excludes problems of echocardiography when assessing left atrial appendage in terms of its complexity. Echocardiography of the left atrial appendage is therefore reserved for its own expert proposal.

Morphology and location of thrombus and sludge in patients with non-valvular atrial fibrillation

BACKGROUND

Stroke and thromboembolism in nonvalvular atrial fibrillation (NVAF) primarily arise from thrombi or sludge in the left atrial appendage (LAA). Comprehensive insight into the characteristics of these formations is essential for effective risk assessment and management.

METHODS

We conducted a single-center retrospective observational of 176 consecutive NVAF patients with confirmed atrial/appendage thrombus or sludge determined by a pre-ablation transesophageal echocardiogram (TEE) from December 2017 to April 2019. We obtained clinical and echocardiographic characteristics, including left atrial appendage emptying velocity (LAAeV) and filling velocity (LAAfV). Data analysis focused on identifying the morphology and location of thrombus or sludge. Patients were divided into the solid thrombus and sludge groups, and the correlation between clinical and echocardiographic variables and thrombotic status was analyzed.

RESULTS

Morphological classification: In total, thrombi were identified in 78 patients, including 71 (40.3%) mass and 7 (4.0%) lamellar, while sludge was noted in 98 (55.7%). Location classification: 92.3% (72/78) of patients had thrombus confined to the LAA; 3.8% (3/78) had both LA and LAA involvement; 2.7% (2/78) had LA, LAA and RAA extended into the RA, the remained 1.2%(1/78) was isolated to RAA. 98.0% (96/98) of patients had sludge confined to the LAA; the remaining 2.0% (2/98) were present in the atrial septal aneurysm, which protrusion of interatrial septum into the RA. The thrombus and sludge groups showed low LAAeV (19.43 ± 9.59 cm/s) or LAAfV (17.40 ± 10.09 cm/s). Only LA dimension ≥ 40 mm was independently associated with the thrombus state in the multivariable model.

CONCLUSION

This cohort study identified rare thrombus morphology and systematically summarized the classification of thrombus morphology. The distribution of thrombus and sludge outside limited to LAA was updated, including bilateral atrial and appendage involvement and rare atrial septal aneurysm sludge. LAAeV and LAAfV were of limited value in distinguishing solid thrombus from sludge.

CLINICAL TRIAL NUMBER

ChiCTR-OCH-13,003,729.

Morphological and functional assessment of the left atrial appendage in daily practice: a comprehensive approach using basic and advanced echocardiography with practical tips

Cardioembolic stroke is the most serious and life-threatening complication of atrial fibrillation (AF), with an associated mortality up to 30% at 12 months. Approximately 47% of thrombi in valvular AF and 91% of thrombi in nonvalvular AF are localized in the left atrial appendage (LAA). Therefore, identification or exclusion of LAA thrombi is critical in many clinical situations. It is essential to assess LAA morphology and function using imaging modalities (particularly echocardiography) before, during, and after interventional procedures such as AF ablation and LAA occlusion. This review article describes the anatomical, physiological, and pathological background of the LAA, followed by an assessment of different echocardiographic modalities. Many practical points are included to improve the diagnostic accuracy and to minimize errors during image acquisition and interpretation. In each clinical scenario where LAA is the crucial target, specific and essential information and parameters are collected.

Left atrial stiffness index - an early marker of left ventricular diastolic dysfunction in patients with coronary heart disease

AIMS

To evaluate the correlation between left atrial stiffness index (LASI) and left ventricular diastolic function in patients with coronary heart disease (CHD) by Autostrain LA technique.

METHODS

This was a retrospective analysis that included a total of 82 CHD patients who had suitable image quality for left atrial strain measurement. According to the 2016 ASE/EACVI guidelines for the echocardiographic assessment of diastolic dysfunction, the patients were divided into three groups: normal left ventricular diastolic function group (n = 26), indeterminate left ventricular diastolic function (n = 36), and left ventricular diastolic dysfunction (LVDD) (n = 20). The left atrial conduit strain (LAScd), Left atrial contractile strain (LASct), left atrial reservoir strain (LASr) and its derived parameters, including LASI and left atrial filling index (LAFI), were compared among the three groups. Furthermore, we conduct a correlation analysis between LASI and left ventricular diastolic function in patients with CHD.

RESULTS

LASr and LAScd in normal group were higher than those in indeterminate group, LASr and LAScd in indeterminate group were higher than those in LVDD group, LASI in normal group was lower than that in indeterminate group, and LASI in indeterminate group was lower than that in LVDD group (P < 0.001). LASct in both normal and indeterminate groups was higher than that in LVDD group (P < 0.05). The LAFI of normal group was lower than that of indeterminate group and LVDD group (P < 0.001). LASI was positively correlated with E/e'(r = 0.822) (P < 0.001). LASr and E/e' were negatively correlated (r = -0.637) (P < 0.001).

CONCLUSION

LASI is closely related to the changes of left ventricular diastolic function in CHD patients.

Potential Role of Left Atrial Strain to Predict Atrial Fibrillation Recurrence after Catheter Ablation Therapy: A Clinical and Systematic Review

Pulmonary vein isolation (PVI) with catheter ablation (CA) represents an effective therapy for atrial fibrillation (AF). Unfortunately, it is still not exempt from severe complications. The balance of risks and benefits should be assessed, and a patient-tailored approach is desirable. So far, several clinical and cardiac imaging parameters have been evaluated to investigate pre- and post-procedural features that could help clinicians in the selection of patients at high risk of a poor outcome after CA. This clinical and systematic review analyses the potential role of new LA parameters, such as LA reservoir strain, to predict AF recurrence after CA therapy. Notably, LA reservoir strain gains substantial clinical importance in patients with paroxysmal AF and when a low CHADS2-VASc score is retrieved. LA reservoir strain provides data concerning the risk of AF recurrence after PVI and, thus, in the management of long-term medical therapy in this patient's group.

Atrial structural remodeling and atrial fibrillation substrate: A histopathological perspective

Atrial fibrillation (AF) substrate progresses with the advancement of atrial structural remodeling, resulting in AF perpetuation and recurrence. Although fibrosis is considered a hallmark of atrial structural remodeling, the histological background has not been fully elucidated because obtaining atrial specimens is difficult, especially in patients not undergoing open-heart surgery. Bipolar voltage reduction evaluated using electroanatomic mapping during AF ablation is considered a surrogate marker for the progression of structural remodeling; however, histological validation is lacking. We developed an intracardiac echocardiography-guided endomyocardial atrial biopsy technique to evaluate atrial structural remodeling in patients undergoing catheter ablation for nonvalvular AF. The histological factors associated with a decrease in bipolar voltage were interstitial fibrosis, as well as an increase in myocardial intercellular space preceding fibrosis, myofibrillar loss, and a decrease in cardiomyocyte nuclear density, which is a surrogate marker for cardiomyocyte density. Cardiomyocyte hypertrophy is closely associated with a decrease in cardiomyocyte nuclear density, suggesting that hypertrophic changes compensate for cardiomyocyte loss. Electron microscopy also revealed that increased intercellular spaces indicated the leakage of plasma components owing to increased vascular permeability. Additionally, amyloid deposition was observed in 4 % of biopsy cases. Only increased intercellular space and interstitial fibrosis were significantly higher for long-standing persistent AF than for paroxysmal AF and associated with recurrence after AF ablation, suggesting that this interstitial remodeling is the AF substrate. An increase in intercellular space that occurs early in AF formation is a therapeutic target for the AF substrate, which prevents irreversible interstitial degeneration due to collagen accumulation. This endomyocardial atrial biopsy technique will allow the collection of atrial tissue from a wide variety of patients and significantly facilitate the elucidation of the mechanisms of atrial cardiomyopathy, structural remodeling, and AF substrates.

Small Left Ventricle in Patients With Atrial Fibrillation Is Associated With Increased Cardiovascular Risk

BACKGROUND

It is still unclear whether small left ventricle (LV) is an adverse structural prognostic feature in patients with atrial fibrillation (AF).

OBJECTIVES

The purpose of this study was to evaluate the association between small LV and risk of cardiovascular events in AF population.

METHODS

From the China-AF registry, 7,764 patients with AF were enrolled and divided into groups with normal, small, and large LV size based on left ventricular end-diastolic dimension (LVEDD) measurement per the American Society of Echocardiography references. Cox models were used to assess the association between LV size or LVEDD with composite cardiovascular events (cardiovascular death, ischemic stroke or systemic embolism, or major bleeding).

RESULTS

There were 308 (4.0%) participants assessed with small LV who were older, with lower body mass and blood pressure, and fewer comorbidities, and 429 (5.5%) were identified with large LV. Compared with the normal LV group, small LV and large LV were significantly associated with higher incidence of composite cardiovascular events (adjusted HR [aHR]: 1.54 [95% CI: 1.07-2.20] for small LV; aHR: 1.36 [95% CI: 1.02-1.81] for large LV) and cardiovascular death (aHR: 1.94 [95% CI: 1.14-3.28] for small LV; aHR: 1.83 [95% CI: 1.24-2.69] for large LV). Small LV was also associated with increased risk of major bleeding [aHR: 2.21 [95% CI: 1.01-4.86]). A U-shaped relationship between LVEDD and composite cardiovascular events was identified (Pnonlinear < 0.001).

CONCLUSIONS

In a prospective AF cohort, small LV was independently associated with an increased risk of cardiovascular events, which needed consideration in risk stratification and management for patients with AF. (ChiCTR-OCH-13003729).

Pre- and post-procedural cardiac imaging (computed tomography and magnetic resonance imaging) in electrophysiology: a clinical consensus statement of the European Heart Rhythm Association and European Association of Cardiovascular Imaging of the European Society of Cardiology

Imaging using cardiac computed tomography (CT) or magnetic resonance (MR) imaging has become an important option for anatomic and substrate delineation in complex atrial fibrillation (AF) and ventricular tachycardia (VT) ablation procedures. Computed tomography more common than MR has been used to detect procedure-associated complications such as oesophageal, cerebral, and vascular injury. This clinical consensus statement summarizes the current knowledge of CT and MR to facilitate electrophysiological procedures, the current value of real-time integration of imaging-derived anatomy, and substrate information during the procedure and the current role of CT and MR in diagnosing relevant procedure-related complications. Practical advice on potential advantages of one imaging modality over the other is discussed for patients with implanted cardiac rhythm devices as well as for planning, intraprocedural integration, and post-interventional management in AF and VT ablation patients. Establishing a team of electrophysiologists and cardiac imaging specialists working on specific details of imaging for complex ablation procedures is key. Cardiac magnetic resonance (CMR) can safely be performed in most patients with implanted active cardiac devices. Standard procedures for pre- and post-scanning management of the device and potential CMR-associated device malfunctions need to be in place. In VT patients, imaging-specifically MR-may help to determine scar location and mural distribution in patients with ischaemic and non-ischaemic cardiomyopathy beyond evaluating the underlying structural heart disease. Future directions in imaging may include the ability to register multiple imaging modalities and novel high-resolution modalities, but also refinements of imaging-guided ablation strategies are expected.

Predictors of systolic function recovery after atrial fibrillation ablation in heart failure patients

INTRODUCTION AND OBJECTIVES

Atrial fibrillation (AF) and heart failure (HF) often coexist. AF catheter ablation improves left ventricular ejection fraction (LVEF), but its impact varies between patients. We aimed to identify predictors of LVEF improvement in HF patients with impaired LVEF undergoing AF ablation.

METHODS

We conducted a retrospective single-center study in HF patients with LVEF <50% undergoing AF catheter ablation between May 2016 and May 2022. The primary endpoint was the LVEF recovery rate ('responders'). Secondary endpoints were one-year safety and effectiveness. We also aimed to validate a prediction model for LVEF recovery.

RESULTS

The study included 100 patients (79% male, median age 60 years, 70% with probable tachycardia-induced cardiomyopathy [TIC], mean LVEF 37%, 29% with paroxysmal AF). After a median follow-up of 12 months after catheter ablation, LVEF improved significantly (36±10% vs. 53±10%, p<0.001), with an 82% responder rate. A suspected diagnosis of TIC (OR 4.916 [95% CI 1.166-20.732], p=0.030), shorter QRS duration (OR 0.969 [95% CI 0.945-0.994], p=0.015), and smaller left ventricle (OR 0.893 [95% CI 0.799-0.999], p=0.049) were independently associated with LVEF improvement. Freedom from any documented atrial arrhythmia was 86% (64% under antiarrhythmic drugs), and the rate of adverse events was 2%. The prediction model had a good discriminative performance (AUC 0.814 [95% CI 0.681-0.947]).

CONCLUSION

In AF patients with HF and impaired LVEF, suspected TIC, shorter QRS duration, and smaller LV diameter were associated with LVEF recovery following AF catheter ablation.

Inflammatory-mediated atrial cardiomyopathy diagnosed using multimodality imaging and successfully treated with prednisolone: a case report

Background

Atrial fibrillation is a common cardiac arrhythmia and often develops secondary to structural cardiac changes. Both the occurrence of atrial fibrillation and/or structural changes of the heart may lead to development of atrial cardiomyopathy and heart failure (HF). However, isolated atrial cardiomyopathy caused by focal atrial thickening is a rare condition, previously only described in case reports as a result of different aetiologies all linked to inflammation.

Case summary

A patient with inflammatory-mediated atrial cardiomyopathy causing atrial fibrillation and acute decompensated HF presented as isolated left atrial wall thickening on transoesophageal echocardiography. The diagnosis was confirmed using multimodality imaging with transthoracic and transoesophageal echocardiography, cardiac magnetic resonance imaging, positron emissions tomography/computer tomography scanning and intracardiac echocardiography-guided endomyocardial biopsy. Despite no specific histological aetiology, the observed atrial cardiomyopathy might be associated with type 1 diabetes mellitus. The patient in the present case was successfully treated with prednisolone.

Discussion

Diabetes mellitus is an important risk factor for developing atrial fibrillation and diabetic cardiomyopathy, due to reduced levels of anti-inflammatory and increased levels of proinflammatory cytokines causing cardiac inflammatory structural remodelling. The regression of the atrial thickening might be due to prednisolone's anti-inflammatory effects and thereby ability to suppress atrial remodelling and reduce the occurrence of atrial fibrillation. However, the effect of prednisolone might only affect the non-manifested inflammatory-mediated atrial remodelling. Due to the rare occurrence of isolated atrial cardiomyopathy a multiple imaging approach during the diagnostic process and follow-ups are essential to determine the aetiology and effect of the treatment.

Steerable Delivery Sheath for Left Atrial Appendage Closure in Patients With Severely Enlarged Left Atria

Background

Enlarged left atrium (LA) is frequently identified in patients who undergo left atrial appendage closure (LAAC) and negatively affects the device's final position and intervention results. Steerable delivery sheath (SDS) could represent an option to overcome these difficulties. We aimed to assess the feasibility of SDS-assisted procedures and compare their efficacy to the standard sheath strategy.

Methods

This study analyzed patients from our institution's LAAC registry who had severe LA enlargement on CT scan (index LA volume >90 mL/m2) and underwent AMULET device implantation between January 2019 and March 2023. The patients underwent postprocedural CT scan to assess the device's position, residual LAA filling, and peridevice leaks.

Results

A total of 195 consecutive patients were screened and 47 (24%) met the inclusion criteria (n = 22 SDS group; n = 25 standard group). There was no difference in baseline clinical, anatomical, or procedural characteristics. The procedural technical success (96%) and complication rates (9% vs 4%; P = .59) were comparable in both groups. Post-LAAC CT scans were obtained in 19 SDS group and 22 standard group patients. We observed significantly lower incidences of residual patent LAA (26% vs 72%; P = .005), peridevice leaks (16% vs 64%; P = .004), and off-axis device position (0% vs 27%; P = .02) in SDS compared to the standard group, suggesting a better LAA sealing.

Conclusions

Severe LA enlargement was frequent among LAAC candidates. In this situation, the use of SDS appears feasible and safe, leading to more efficient closures on follow-up imaging without a higher risk of periprocedural complications.

Feasibility and image quality of bright-blood and black-blood phase-sensitive inversion recovery (BOOST) sequence in clinical practice using for left atrial visualization in patients with atrial fibrillation

OBJECTIVES

Visualizing left atrial anatomy including the pulmonary veins (PVs) is important for planning the procedure of pulmonary vein isolation with ablation in patients with atrial fibrillation (AF). The aims of our study are to investigate the feasibility of the 3D whole-heart bright-blood and black-blood phase-sensitive (BOOST) inversion recovery sequence in patients with AF scheduled for ablation or electro-cardioversion, and to analyze the correlation between image quality and heart rate and rhythm of patients.

METHODS

BOOST was performed for assessing PVs both with T2 preparation pre-pulse (T2prep) and magnetization transfer preparation (MTC) in 45 patients with paroxysmal or permanent AF scheduled for ablation or electro-cardioversion. Image quality analyses were performed by two independent observers. Qualitative assessment was made using the Likert scale; for quantitative analysis, signal to noise ratios (SNR) and contrast to noise ratios (CNR) were calculated for each PV. Heart rate and rhythm were analyzed based on standard 12-lead ECGs.

RESULTS

All MTC-BOOST acquisitions achieved diagnostic quality in the PVs, while a significant proportion of T2prep-BOOST images were not suitable for assessing PVs. SNR and CNR values of the MTC-BOOST bright-blood images were higher if patients had sinus rhythm. We found a significant or nearly significant negative correlation between heart rate and the SNR and CNR values of MTC-BOOST bright-blood images.

CONCLUSION

3D whole-heart MTC-BOOST bright-blood imaging is suitable for visualizing the PVs in patients with AF, producing diagnostic image quality in 100% of cases. However, image quality was influenced by heart rate and rhythm.

CLINICAL RELEVANCE STATEMENT

The novel 3D whole-heart BOOST CMR sequence needs no contrast administration and is performed during free-breathing; therefore, it is easy to use for a wide range of patients and is suitable for visualizing the PVs in patients with AF.

KEY POINTS

• The applicability of the novel 3D whole-heart bright-blood and black-blood phase-sensitive sequence to pulmonary vein imaging in clinical practice is unknown. • Magnetization transfer-bright-blood and black-blood phase-sensitive imaging is suitable for visualizing the pulmonary veins in patients with atrial fibrillation with excellent or good image quality. • Bright-blood and black-blood phase-sensitive cardiac magnetic resonance sequence is easy to use for a wide range of patients as it needs no contrast administration and is performed during free-breathing.

Pathophysiology and clinical relevance of atrial myopathy

Atrial myopathy is a condition that consists of electrical, structural, contractile, and autonomic remodeling of the atria and is the substrate for development of atrial fibrillation, the most common arrhythmia. Pathophysiologic mechanisms driving atrial myopathy are inflammation, oxidative stress, atrial stretch, and neurohormonal signals, e.g., angiotensin-II and aldosterone. These mechanisms initiate the structural and functional remodeling of the atrial myocardium. Novel therapeutic strategies are being developed that target the pathophysiologic mechanisms of atrial myopathy. In this review, we will discuss the pathophysiology of atrial myopathy, as well as diagnostic and therapeutic strategies.

The Role of Immune Cells Driving Electropathology and Atrial Fibrillation

Atrial fibrillation (AF) is the most common progressive cardiac arrhythmia worldwide and entails serious complications including stroke and heart failure. Despite decades of clinical research, the current treatment of AF is suboptimal. This is due to a lack of knowledge on the mechanistic root causes of AF. Prevailing theories indicate a key role for molecular and structural changes in driving electrical conduction abnormalities in the atria and as such triggering AF. Emerging evidence indicates the role of the altered atrial and systemic immune landscape in driving this so-called electropathology. Immune cells and immune markers play a central role in immune remodeling by exhibiting dual facets. While the activation and recruitment of immune cells contribute to maintaining atrial stability, the excessive activation and pronounced expression of immune markers can foster AF. This review delineates shifts in cardiac composition and the distribution of immune cells in the context of cardiac health and disease, especially AF. A comprehensive exploration of the functions of diverse immune cell types in AF and other cardiac diseases is essential to unravel the intricacies of immune remodeling. Usltimately, we delve into clinical evidence showcasing immune modifications in both the atrial and systemic domains among AF patients, aiming to elucidate immune markers for therapy and diagnostics.

Left atrial strain: A memory of the severity of atrial myocardial stress in atrial fibrillation

BACKGROUND

Left atrial (LA) strain is a simple marker of LA function. The aim of the study was to evaluate the determinants of atrial cardiomyopathy in AF.

METHODS

In this pilot study, we prospectively evaluated clinical, biological, metabolomic and echocardiographic parameters for 85 consecutive patients hospitalized for atrial fibrillation (AF) with restoration of sinus rhythm at 6 months. Eighty-one patients with an analysable LA strain at 6 months were divided into groups according to median reservoir strain:<23.3% (n=40) versus≥23.3% (n=41).

RESULTS

Compared to patients with the highest LA strain, patients with lowest LA strain had multiple differences at admission: clinical (older age; more frequent history of AF; more patterns of persistent AF); biological (higher fasting blood glucose levels, glycated haemoglobin, high-sensitivity C-reactive protein, and urea; lower glomerular filtration rate); metabolomic (higher levels of kynurenine, kynurenine/tryptophan, and urea/creatinine; lower levels of arginine and methionine/methionine sulfoxide); and echocardiographic (higher two-dimensional end-systolic LA volume [LAV] indexes; higher three-dimensional end-systolic and end-diastolic LAV and right atrial volume indexes; lower LA and right atrial emptying fractions and three-dimensional right ventricular ejection fraction) (all P<0.05). Area under the receiver operating characteristic curve to predict LA strain alteration at 6 months was highest for a combined score including clinical, biological, metabolomic and echocardiographic variables at admission (area under the receiver operating characteristic curve 0.871; P<0.0001).

CONCLUSIONS

LA reservoir strain could be a memory of initial atrial myocardial stress in AF. It can be predicted using a combination of clinical, biological, metabolomic and echocardiographic admission variables.

Left atrial deformation analysis in patients with non-ischaemic dilated cardiomyopathy in atrial fibrillation

Aims

Atrial fibrillation (AF) is a common comorbidity in non-ischaemic dilated cardiomyopathy (NIDCM) affecting conventional measures of left atrial (LA) function. We aimed to determine whether LA function analysis could identify patients at higher risk of major cardiovascular events (MACEs).

Methods and results

A retrospective study of patients with NIDCM in AF referred to a single centre for transthoracic echocardiography (TTE) between 2015 and 2019. Peak atrial longitudinal strain (PALS) was measured along with LA emptying fraction and LA filling index (LAFI = E wave/PALS). Cox regression analysis was conducted. A total of 153 patients were included [median age 74 years, left ventricular ejection fraction (LVEF) 35%], and 57 (37.3%) had MACE after a median follow-up of 3.2 years. LAFI was the only independent TTE parameter associated with MACE after adjustment for age, diabetes, LVEF, left ventricular global longitudinal strain (LV-GLS), and LA volume index [adjusted hazard ratio (HR) = 1.02 per point increase, P = 0.024], with the best cut-off at ≥15. LAFI ≥15 predicted each of MACE components when separately analysed: MACE HR = 1.95, 95% confidence interval (CI) 1.16-3.30; cardiovascular death HR = 3.68, 95% CI 1.41-9.56, heart failure admission HR = 2.13, 95% CI 1.19-3.80, and ventricular arrhythmia HR = 4.72, 95% CI 1.52-14.67. Higher LAFI was associated with worsening LV-GLS, E/e', systolic pulmonary artery (PA) pressure, tricuspid annular plane systolic excursion, and right ventricular to PA coupling.

Conclusion

LA deformation analysis is feasible in patients with NIDCM presenting with AF. LAFI may identify patients at higher risk of MACE and correlates with higher pulmonary pressures and worse right ventricular function, suggesting an elevation of left-sided ventricular pressures in patients with higher LAFI.

Echocardiographic parameters indicating left atrial reverse remodeling after catheter ablation for atrial fibrillation

Background

The echocardiographic parameters total atrial conduction time (PA-TDI duration), left atrial (LA) volume index (LAVI), and LA strain reflect adverse atrial remodeling and predict atrial fibrillation (AF).

Objectives

The aim of this study was to investigate echocardiographic parameters indicating reverse LA remodeling and potential associations with AF recurrence after pulmonary vein isolation (PVI).

Methods

This prospective observational study consecutively enrolled patients scheduled for PVI for symptomatic AF. Electrocardiogram (ECG) test and transthoracic echocardiography were performed the day before and after PVI and again 3 months later. AF recurrence was determined by Holter ECG at 3 months, and telephone follow-up at 12 months, after PVI. The parameters of LA remodeling [PA-TDI, LAVI, and LA strain analysis: reservoir strain (LASr), conduit strain (LAScd), contraction strain (LASct)] were determined by transthoracic echocardiography.

Results

A total of 48 patients were included in the study (mean age: 61.4 ± 12.2 years). PA-TDI significantly decreased the day after PVI compared with the baseline (septal PA-TDI 103 ± 13 vs. 82 ± 14.9 ms, p ≤ 0.001; lateral PA-TDI 122.4 ± 14.8 vs. 106.9 ± 14.4 ms, p ≤ 0.001) and at the 3-month follow-up (septal PA-TDI: 77.8 ± 14.5, p ≤ 0.001; lateral PA-TDI 105.2 ± 16.1, p ≤ 0.001). LAVI showed a significant reduction at the 3-month follow-up compared with the baseline (47.7 ± 14.4 vs. 40.5 ± 9.7, p < 0.05). LASr, LAScd, and LASct did not change after PVI compared with the baseline. AF recurred in 10 patients after PVI (21%). Septal PA-TDI, septal a', and LAVI/a' determined the day after PVI were associated with AF recurrence.

Conclusion

Changes in echocardiographic parameters of LA remodeling and function indicate that functional electromechanical recovery preceded morphological reverse remodeling of the left atrium after PVI. Furthermore, these changes in echocardiographic parameters indicating LA reverse remodeling after PVI may identify patients at high risk of AF recurrence.

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.

Evaluation of Left Atrial Function in Patients with Paroxysmal Atrial Fibrillation Using Left Atrial Automatic Myocardial Functional Imaging Ultrasonography

Aim

To evaluate volume and strain of the left atrium (LA) in people suffering from paroxysmal atrial fibrillation which is not valvular (NVPAF) using the new technology of left atrial automatic myocardial function imaging (AFILA) and to analyze prognostic factors in patients with NVPAF by follow-up.

Methods

Between August 2019 and August 2022, a total of 80 NVPAF patients and 60 normal control patients who were hospitalized in the Department of Cardiology were included in the study. The LA volume and strain parameters of the two groups were analyzed. The differences in LA function (LAF) parameters were compared between the two groups to generate the receiver operating characteristic curve (ROC) and calculate the area under the curve (AUC), sensitivity, and specificity of each parameter. Follow-up was conducted on the 80 NVPAF patients included, their treatment methods after admission and their rehospitalization due to heart events were recorded, and independent risk factors influencing the prognosis of NVPAF were obtained.

Results

A total of 140 patients participated in the study, including 80 in the NVPAF group and 60 in the normal control group. There was no statistically significant difference in age and sex between the two groups. Compared to the normal group, the LA minimum volume (LAVmin), LA maximum volume (LAVmax), and volume at onset of LA contraction (LAVpreA) in the NVPAF group were significantly increased. The LA emptying fraction (LAEF) was significantly decreased, and LA reservoir strain (S_R), LA conduit strain (S_CD), and LA contractile strain (S_CT) were significantly compromised (P < 0.05). There was no significant difference in LA evacuation volume (LAEV) reduction (P > 0.05). Logistic regression analysis of LAF parameters in NVPAF patients showed that LAEF and S_R were independently correlated with NVPAF (odds ratio values: 0.883 (0.827-0.943), P < 0.001; 0.916 (0.569-1.474), P = 0.047). The ROC curve results showed that LAEF had a high efficiency in the diagnosis of NVPAF, with P < 0.001, AUC of 0.843, sensitivity of 0.788, and specificity of 0.867. For the LA strain parameters, the S_R test efficiency was higher, with P < 0.001, AUC of 0.762, sensitivity of 0.713, and specificity of 0.783. There was a strong correlation between S_R and LAEF in patients with no end event and those with end event. The ROC curve revealed that the S_R was better than LAEF in predicting prognosis of patients with AF (AUC = 0.914, P < 0.0001 vs. AUC = 0.876, P < 0.0001). S_R of 10.5 and LAEF of 21 were the cut-off values for endpoint events in NVPAF patients, with sensitivity of 0.909 and 0.727 and specificity of 0.904 and 0.901, respectively.

Conclusions

AFILA ultrasound technology comprehensively evaluated the LA size and function in patients with NVPAF. The LAEF and S_R were independently correlated with NVPAF and can determine the prognosis of patients with NVPAF.

Left Atrial Strain and Incident Atrial Fibrillation in Older Adults

Atrial fibrillation (AF) is frequent in older adults and associated with left atrial (LA) dysfunction. LA strain (LAε) and LA strain rate (LASR) may detect subclinical LA disease. We investigated whether reduced LAε and LASR predict new-onset AF in older adults without history of AF or stroke. LAε and LASR were assessed by speckle-tracking echocardiography in 824 participants from the community-based Cardiovascular Abnormalities and Brain Lesions study. Positive longitudinal LAε and LASR during ventricular systole, LASR during early ventricular diastole, and LASR during LA contraction were measured. Cause-specific hazards regression model evaluated the association of LAε and LASR with incident AF, adjusting for pertinent covariates. The mean age was 71.1 ± 9.2 years (313 men, 511 women). During a mean follow-up of 10.9 years, new-onset AF occurred in 105 participants (12.7%). Lower LAε and LASR at baseline were observed in patients with new-onset AF (all p <0.01). In multivariable analysis, positive longitudinal LAε (adjusted hazard ratio [HR] per SD decrease 2.05, confidence interval [CI] 1.24 to 3.36) and LASR during LA contraction (HR per SD increase 2.24, CI 1.37 to 3.65) remained associated with new-onset AF, independently of LA volumes and left ventricular function. Along with positive longitudinal LAε, reduced LASR during ventricular systole predicted AF in participants with LA volume below the median value (HR 2.54, CI 1.10 to 6.09), whereas reduced LASR during LA contraction predicted AF in participants with larger LA (HR 2.35, CI 1.31 to 4.23). In conclusion, reduced positive longitudinal LAε and LASR predict new-onset AF in older adults regardless of LA size and may improve AF risk stratification.

Atrial Myopathy Quantified by Speckle-tracking Echocardiography in Mice

BACKGROUND

Emerging evidence suggests that atrial myopathy may be the underlying pathophysiology that explains adverse cardiovascular outcomes in heart failure (HF) and atrial fibrillation. Lower left atrial (LA) function (strain) is a key biomarker of atrial myopathy, but murine LA strain has not been described, thus limiting translational investigation. Therefore, the objective of this study was to characterize LA function by speckle-tracking echocardiography in mouse models of atrial myopathy.

METHODS

We used 3 models of atrial myopathy in wild-type male and female C57Bl6/J mice: (1) aged 16 to 17 months, (2) Ang II (angiotensin II) infusion, and (3) high-fat diet+Nω-nitro-L-arginine methyl ester (HF with preserved ejection fraction, HFpEF). LA reservoir, conduit, and contractile strain were measured using speckle-tracking echocardiography from a modified parasternal long-axis window. Left ventricular systolic and diastolic function, and global longitudinal strain were also measured. Transesophageal rapid atrial pacing was used to induce atrial fibrillation.

RESULTS

LA reservoir, conduit, and contractile strain were significantly reduced in aged, Ang II and HFpEF mice compared with young controls. There were no sex-based interactions. Left ventricular diastolic function and global longitudinal strain were lower in aged, Ang II and HFpEF, but left ventricular ejection fraction was unchanged. Atrial fibrillation inducibility was low in young mice (5%), moderately higher in aged mice (20%), and high in Ang II (75%) and HFpEF (83%) mice.

CONCLUSIONS

Using speckle-tracking echocardiography, we observed reduced LA function in established mouse models of atrial myopathy with concurrent atrial fibrillation inducibility, thus providing the field with a timely and clinically relevant platform for understanding the pathophysiology and discovery of novel treatment targets for atrial myopathy.

Progressive alterations of left atrial and ventricular volume and strain across chronic kidney disease stages: a speckle tracking echocardiography study

Background

It has been a scarcity of evidence regarding differences in left ventricular (LV) and left atrial (LA) size and strain changes across stages of chronic kidney disease (CKD) and which echocardiographic parameters could be utilized to predict the decline of glomerular filtration rate (GFR).

Objectives

This study aimed to evaluate the alterations of LV and LA strain across the reduction of renal function and potential echocardiographic parameters which could be correlated with the GFR decline among patients with CKD.

Method

A cross-sectional study was conducted on 169 CKD patients at Bach Mai General Hospital, Hanoi, Vietnam from April to November 2022. Demographic, clinical and laboratory characteristics of patients were collected. Transthoracic echocardiography was performed to measure LV and LA size and strains. Jonckheere-Terpstra test was used to measure the tendency of change. Multivariate linear regression models were performed to find associations between different echocardiographic parameters and renal function reduction.

Results

The number of patients with CKD stages 1, 2, 3, 4, and 5 was 21 (12.4%), 28 (16.6%), 27 (16.0%), 22 (13.0%) and 71 (42.0%), respectively. CKD severity was positively associated with LV diastolic and systolic diameters, LV mass, E/e' ratio, and maximal tricuspid regurgitation velocity (TR max), and negatively correlated with the LV global longitudinal strain. Higher severity of CKD stage was associated with higher LA diameter, LA strain, and volume in four and two-chamber views, and lower LA reservoir and conduit function. Left ventricular mass (β = 0.068), ejection fraction (β = 0.112) and left atrial reservoir (β = -0.077) were associated with reduced GFR.

Conclusion

Left ventricular mass, ejection fraction, and atrial longitudinal strain by STE should be done at the earlier stages of CKD patients for better follow-up of GFR decline.

Computed Tomography Scan Evidence for Left Atrial Appendage Short-Term Remodeling Following Percutaneous Occlusion: Impact of Device Oversizing

Background The interrelationships between left atrial appendage (LAA) dimensions and device following implantation are unknown. We aimed to analyze the impact of Watchman device implantation on LAA dimensions following its percutaneous closure and potential predictors of remodeling. Methods and Results All consecutive LAA closure procedures performed at 2 centers between November 2017 and December 2020 were included in the WATCH-DUAL (Watchman 2.5 Versus Watchman FLX in a Dual-Center Left Atrial Appendage Closure Cohort) registry. This study included patients who had pre- and postintervention computed tomography scan analysis. The LAA and device dimensions were measured in a centralized core lab by 3-dimensional computed tomography scan reconstruction methods, focusing on the device landing zone. This analysis included 104 patients (age, 76.0 [range, 72.0-83.0] years; 72% men; 53% Watchman FLX; 47% Watchman 2.5). The baseline characteristics were comparable between Watchman 2.5 and Watchman FLX groups, except for the higher use of oversizing in the latter group. The median delay for computed tomography control was 49 (range, 43-64) days. The landing zone area (median, 446 [range, 363-523] versus 290 [222-366] mm2; P<0.001) and minimal diameter (median, 23.0 [range, 20.7-24.8] versus 16.7 [14.7-19.4] mm; P<0.001) significantly increased after implantation. The absolute (median, 157 [range, 98-220] versus 85 [18-148] mm2, P<0.001) and relative (median, 50% [range, 32%-79%] versus 26% [4%-50%]; P<0.001) increases in landing zone area were more pronounced in patients with oversized device. Baseline LAA dimensions were smaller, landing zone eccentricity larger, and oversized device more frequent in patients with significant overexpansion compared with the others. Conclusions LAA dimensions increased at the site of the Watchman prosthesis after implantation, suggesting a local positive remodeling after the procedure. This phenomenon was more pronounced in the case of oversized devices.

[Echocardiography in cardiac arrhythmias]

Echocardiography plays a key role in planning and guidance of electrophysiological procedures. After exclusion of structural heart disease, echocardiography provides insight into the extent of left atrial remodeling by determining left atrial metrics. This "biomarker" is associated with the risk of new-onset atrial fibrillation and predictive of atrial fibrillation recurrence after ablation. Transesophageal echocardiography is necessary to exclude left atrial thrombi and is able to guide a transseptal puncture. In case of a rare but life-threatening cardiac tamponade, an echocardiographic-guided pericardiocentesis ensures quick and effective treatment. Left ventricular ejection fraction and deformation analysis determined by echocardiography are established methods for risk stratification in patients with systolic dysfunction and used to guide pharmacological and device therapy.

Inter-center reproducibility of standard and advanced echocardiographic parameters in the EACVI-AFib echo registry

AIM

we sought to test the inter-center reproducibility of 16 echo laboratories involved in the EACVI-Afib Echo Europe.

METHODS

This was done on a dedicated setting of 10 patients with sinus rhythm (SR) and 10 with persistent atrial fibrillation (AF), collected by the Principal Investigator. Images and loops of echo-exams were stored and made available for labs. The tested measurements included main echo-Doppler parameters, global longitudinal strain (GLS) and peak atrial longitudinal strain (PALS).

RESULTS

Single measures interclass correlation coefficients (ICCs) of left ventricular mass and ejection fraction were suboptimal in both patients with SR and AF. Among diastolic parameters, ICCs of deceleration time were poor, in particular in AF (=.50). ICCs of left atrial size and function, besides optimal in AF, showed an acceptable despite moderate concordance in SR. ICC of GLS was .81 and .78 in SR and AF respectively. ICCs of PALS were suitable but lower in 4-chamber than in 2-chamber view. By depicting the boxplot of the 16 laboratories, GLS distribution was completely homogeneous in SR, whereas GLS of AF and PALS of both SR and AF presented a limited number of outliers. GLS mean ± SE of the 16 labs was 19.7 ± .36 (95% CI: 18.8-20.4) in SR and 16.5 ± .29 (95% CI: 15.9-17.1) in AF, whereas PALS mean ± SE was 43.8 ± .70 (95% CI: 42.3-45.3) and 10.2 ± .32 (95% CI: 9.5-10.9) respectively.

CONCLUSION

While the utilization of some standard-echo variables should be discouraged in registries, the application of GLS and PALS could be largely promoted because their superior reproducibility, even in AF.

Association of Atrial Fibrillation With Stroke and Dementia Accounting for Left Atrial Function and Size

BACKGROUND

Atrial fibrillation (AF) is associated with higher risks of ischemic stroke (IS) and dementia. Whether alterations in left atrial (LA) function or size-atrial myopathy-confound these associations remains unknown.

OBJECTIVES

The purpose of this study was to examine the association of prevalent and incident AF with ischemic stroke and dementia in the ARIC (Atherosclerosis Risk In Communities) study, adjusting for LA function and size.

METHODS

Participants at visit 5 (2011-2013) with echocardiographic LA function (reservoir, conduit, contractile strain, and emptying fraction) and size (maximal, minimal volume index) data, and without prevalent stroke or dementia were followed through 2019. For analysis, we used time-varying Cox regression.

RESULTS

Among 5,458 participants (1,193 with AF, mean age of 76 years) in the stroke analysis and 5,461 participants (1,205 with AF, mean age of 75 years) in the dementia analysis, 209 participants developed ischemic stroke, and 773 developed dementia over 7.1 years (median). In a demographic and risk factor-adjusted model, AF was significantly associated with ischemic stroke (HR, 1.63; 95% CI: 1.11-2.37) and dementia (HR: 1.38, 95% CI: 1.13-1.70). After additionally adjusting for LA reservoir strain, these associations were attenuated and no longer statistically significant (stroke [HR: 1.33, 95% CI: 0.88-2.00], dementia [HR: 1.15, 95% CI: 0.92-1.43]). Associations with ischemic stroke and dementia were also attenuated and not statistically significant after adjustment for LA contractile strain, emptying fraction, and minimal volume index.

CONCLUSIONS

AF-ischemic stroke and AF-dementia associations were not statistically significant after adjusting for measures of atrial myopathy. This proof-of-concept analysis does not support AF as an independent risk factor for ischemic stroke and dementia.

Left atrial appendage strain predicts subclinical atrial fibrillation in embolic strokes of undetermined source

Aims

Left atrial (LA) strain is promising in prediction of clinical atrial fibrillation (AF) in stroke patients. However, prediction of subclinical AF is critical in patients with embolic strokes of undetermined source (ESUS). The aim of this prospective study was to investigate novel LA and left atrial appendage (LAA) strain markers in prediction of subclinical AF in ESUS patients.

Methods and results

A total of 185 patients with ESUS, mean age 68 ± 13years, 33% female, without diagnosed AF, were included. LAA and LA function by conventional echocardiographic parameters and reservoir strain (Sr), conduit strain (Scd), contraction strain (Sct), and mechanical dispersion (MD) of Sr were assessed with transoesophageal and transthoracic echocardiography. Subclinical AF was detected by insertable cardiac monitors during follow-up. LAA strain was impaired in 60 (32%) patients with subclinical AF compared to those with sinus rhythm: LAA-Sr, 19.2 ± 4.5% vs. 25.6 ± 6.5% (P < 0.001); LAA-Scd, -11.0 ± 3.1% vs. -14.4 ± 4.5% (P < 0.001); and LAA-Sct, -7.9 ± 4.0% vs. -11.2 ± 4% (P < 0.001), respectively, while LAA-MD was increased, 34 ± 24 ms vs. 26 ± 20 ms (P = 0.02). However, there was no significant difference in phasic LA strain or LA-MD. By ROC analyses, LAA-Sr was highly significant in prediction of subclinical AF and showed the best AUC of 0.80 (95% CI 0.73-0.87) with a sensitivity of 80% and a specificity of 73% (P < 0.001). LAA-Sr and LAA-MD were both independent and incremental markers of subclinical AF in ESUS patients.

Conclusion

LAA function by strain and mechanical dispersion predicted subclinical AF in ESUS patients. These novel echocardiographic markers may improve risk stratification in ESUS patients.

Frequency and Clinical Significance of Atrial Cavities in situ Thrombosis: A Large-Scale Study and Literature Review

Background

Atrial tachyarrhythmias are the main cause of atrial thrombosis, and are usually in the left appendage. The prevalence and causes of endocavitarian thrombosis have not been investigated in recent large-scale studies. Aim of our work was to describe the epidemiology, the clinical characteristics and predisposing factors of "extra-appendicular" atrial thrombosis and to report a systematic review of recent literature.

Methods and Results

5,862 consecutive adult patients referred to a transesophageal echocardiographic exam, were enrolled. A total of 175 subjects with Atrial Thrombosis were found with a prevalence of 2.98%; among those 22 was found in left (0.38%) and 2 in the right (0.03%) atrium. Among the 22 patients with left atrial thrombosis, 8 were associated with prosthetic valves, 4 with mitral stenosis and the remaining with hypercoagulative conditions (cancer, septic shock, eosinophilic pneumonia, cardiogenic shock and warfarin under-dosage in permanent atrial fibrillation and decompensated heart failure). Cancer was associated in one of the two patients with a right atrial clot. The review of the literature from 2000 to December 2019 revealed conflicting results of 48 case reports of atrial cavity thrombosis; pooling this data proved the rarity of extra-appendage thrombosis and confirmed its association with a valvular heart disease or a systemic hypercoagulable state.

Conclusions

Atrial "extra-appendage" thrombosis is a rare condition usually associated to "valvular" atrial fibrillation (such as prosthetic valves and mitral stenosis). A minority, but significant, cases are secondary to a thrombophilic conditions. In absence of valvular heart disease an underlying condition should be sought.

Imaging in atrial fibrillation: A way to assess atrial fibrosis and remodeling to assist decision-making

The 2020 ESC atrial fibrillation (AF) guidelines suggest the novel 4S-AF scheme for the characterization of AF. Imaging techniques could be helpful for this objective in everyday clinical practice, and information derived from these techniques reflects basic aspects of the pathophysiology of AF, which may facilitate treatment decision-making, and optimal management of AF patients. The aim of this review is to provide an overview of the mechanisms associated with atrial fibrosis and to describe imaging techniques that may help the management of AF patients in clinical practice. Transthoracic echocardiography is the most common procedure given its versatility, safety, and simplicity. Transesophageal echocardiography provides higher resolution exploration, and speckle tracking echocardiography can provide incremental functional and prognostic information over conventional echocardiographic parameters. In addition, LA deformation imaging, including LA strain and strain rate, are related to the extent of fibrosis. On the other hand, multidetector-row computed tomography and cardiac magnetic resonance provide higher resolution data and more accurate assessment of the dimensions, structure, and spatial relationships of the LA. Imaging is central when deciding on catheter ablation or cardioversion, and helps in selecting those patients who will really benefit from these procedures. Moreover, imaging enhances the understanding of the underlying mechanisms of atrial remodeling and might assists in refining the risk of stroke, which help to select the best medical therapies/interventions. In summary, evaluation of LA enlargement, LA remodeling and fibrosis with imaging techniques adds clinical and prognostic information and should be assessed as a part of routine comprehensive AF evaluation.

Atrial cardiomyopathy: Current and future imaging methods for assessment of atrial structure and function

Changes in atrial size and function have historically been considered a surrogate marker of ventricular dysfunction. However, it is now recognized that atrial cardiomyopathy (ACM) may also occur as a primary myocardial disorder. Emerging evidence that ACM is a major risk factor for atrial fibrillation, heart failure, and thromboembolic stroke, has highlighted the significance of this disorder and the need for better assessment of atrial metrics in clinical practice. Key barriers in this regard include a lack of standardized criteria or hierarchy for the diagnosis of ACM and lack of consensus for the most accurate phenotyping methods. In this article we review existing literature on ACM, with a focus on current and future non-invasive imaging methods for detecting abnormalities of atrial structure and function. We discuss the relative advantages and disadvantages of transthoracic echocardiography and cardiac magnetic resonance imaging for assessing a range of parameters, including atrial size and contractile function, strain, tissue characteristics, and epicardial adipose tissue. We will also present the potential application of novel imaging methods such as sphericity index and four- or five-dimensional flow.

Radiomic Phenotype of Periatrial Adipose Tissue in the Prognosis of Late Postablation Recurrence of Idiopathic Atrial Fibrillation

The aim of the study is to find new predictors of postablation atrial fibrillation (AF) recurrence in patients with lone AF using a texture analysis of the periatrial adipose tissue (PAAT) of the left atrium.

Materials and Methods

Forty-three patients admitted for lone AF catheter ablation, who had undergone multispiral coronary angiography, were enrolled in the study. PAAT segmentation was performed using 3D Slicer application followed by extraction of 93 radiomic features. At the end of the follow-up period, patients were divided into 2 groups depending on the presence or absence of AF recurrence.

Results

12 months of follow-up after catheter ablation, postablation AF recurrence was reported in 19 out of 43 patients. Of 93 extracted radiomic features of PAAT, statistically significant differences were observed for 3 features of the Gray Level Size Zone matrix. At the same time, only one radiomic feature of PAAT, Size Zone Non Uniformity Normalized, was an independent predictor of postablative recurrence of AF after catheter ablation and 12 months of follow-up (McFadden's R²=0.451, OR - 0.506, 95% CI: 0.331‒0.776, p<0.001).

Conclusion

The radiomic analysis of periatrial adipose tissue may be considered as a promising non-invasive method for predicting adverse outcomes of the catheter treatment, which opens the possibilities for planning and correction of patient management tactics after intervention.

Clinical outcomes of left atrial appendage occlusion in patients with previous intracranial or gastrointestinal bleeding: Insights from the LOGIC (Left atrial appendage Occlusion in patients with Gastrointestinal or IntraCranial bleeding) International Multicenter Registry

AIMS

To compare outcomes of patients who underwent left atrial appendage occlusion (LAAO) for nonvalvular atrial fibrillation (NVAF) and contraindication to anticoagulants due to history of either gastrointestinal (GI) or intracranial (IC) bleeding.

METHODS

Patients with NVAF that underwent LAAO for GI or IC bleeding from seven centers were included in this observational study. Baseline characteristics, procedural features, and follow-up data were collected, and compared between the two groups. The primary outcomes were incidence of ischemic and hemorrhagic events at 12-month.

RESULTS

Six hundred twenty-eight patients were included, 57% with previous GI-bleeding, and 43% with previous IC-bleeding. Median CHA 2 DS 2-VASc score was 4 (interquartile range [IQRs]: 3-5) for both GI-bleeding and IC-bleeding patients, while GI-bleeding patients had a higher HAS-BLED score (4 [IQRs: 3-4] vs. 3 [IQRs]: 2-3]; p = 0.001). At 12-month follow-up, relative risk reduction for stroke was similar between the two groups. The GI-bleeding group had more hemorrhagic events compared to IC-bleeding group (any bleeding 8.4% vs. 3.2%; p = 0.012; major bleeding BARC 3-5: 4.3% vs. 1.8; p = 0.010). At multivariate analysis history of GI bleeding was an independent predictor of hemorrhagic events (adjusted HR: 2.39, 95% confidence interval: 1.02-5.63; p = 0.047).

CONCLUSIONS

Outcomes after LAAO may be affected by the different indications for the procedure. In our study, GI-bleeding and IC-bleeding as indication to LAAO differ in their baseline characteristics. LAAO confirms its efficacy in ischemic risk reduction in both groups, while GI bleeding seems to be an independent predictor of bleeding recurrence at 12 months behind the antithrombotic regimen.

Left atrial strain evaluation to assess left ventricle diastolic dysfunction and heart failure with preserved ejection fraction: a guide to clinical practice : Left atrial strain and diastolic function

Although frequently unrecognized, left atrium (LA) function plays a key role in global cardiac performance as it modulates left ventricle (LV) filling through three main functions: the LA reservoir, conduit and booster pump. Given the interdependence between the LA and the LV, it is known that LA dimension and/or LA function can be used as a surrogate for LV diastolic function.Recently, LA deformation analysis using 2-dimensional (2D) speckle tracking echocardiography (STE) strain emerged as a promising non-invasive technique that can help to estimate LV filling pressures (LVFP) and diagnose heart failure with preserved ejection fraction (HFpEF), as recently proposed in the recent 2022 European Association of Cardiovascular Imaging (EACVI) consensus which included LA reservoir strain as an additive parameter to estimate LVFP.This article aims to review the latest evidence regarding the role of LA strain in the assessment and management of LV diastolic dysfunction (LVDD) and HFpEF, providing a clinical guide with tips and tricks to use LA strain as a new technique to help to estimate LVFP.

P-wave parameters and their association with thrombi and spontaneous echo contrast in the left atrial appendage

BACKGROUND

The aim of this study was to examine the prevalence of abnormal P-wave parameters in patients with thrombus and/or spontaneous echo contrast (SEC) in the left atrial appendage (LAA), and to identify P-wave parameters particularly associated with thrombus and SEC formation.

HYPOTHESIS

We presume a significant relationship of P-wave parameters with thrombi and SEC.

METHODS

All patients in whom a thrombus or SEC was detected in the LAA on transoesophageal echocardiography were included in this study. Patients at risk (CHA2DS2-VASc Score ≥3) and routine transoesophageal echocardiography to exclude thrombi served as the control group. A detailed ECG analysis was performed.

RESULTS

Of a total of 4062 transoesophageal echocardiographies, thrombi and SEC were detected in 302 patients (7.4%). Of these patients, 27 (8.9%) presented with sinus rhythm. The control group included 79 patients. There was no difference in mean CHA2DS2-VASc score in the two groups (p = .182). A high prevalence of abnormal P-wave parameters was detected in patients with thrombus/SEC. Indicators for the presence of thrombi or SEC in the LAA were P-wave duration >118 ms (Odds ratio (OR) 3.418, Confidence interval (CI) 1.522-7.674, p < .001), P-wave dispersion >40 ms (OR 2.521, CI 1.390-4.571, p < .001) and advanced interatrial block (OR 1.431, CI 1.033-1.984, p = .005).

CONCLUSION

Our study revealed that several P-wave parameters are associated with thrombi and SEC in the LAA. The results may help identify patients who are at particularly high risk for thromboembolic events (e.g., in patients with embolic stroke of undetermined source).

Multimodality imaging assessment of the Biatrial remodeling of the burden of atrial high-rate episodes in patients with cardiac implanted electronic devices

AIMS

The underlying mechanisms of atrial remodeling in cardiac implanted electronic device(CIED)-detected atrial high-rate episodes(AHRE) remains to be elucidated.

METHODS

A cardiac computed tomography and a strain echocardiography were performed to delineate the structural and functional characteristics of both atria. Biatrial volumes, emptying fraction(EF) and peak atrial longitudinal/contractile strain(PALS/PACS) were evaluated. All AHRE were analyzed.

RESULTS

A total of 80 CIED patients with AHRE were categorized by AHRE duration into 3 groups: Group 1: <6 min(n = 42), Group 2: 6 min ∼ 6 h(n = 23), and Group 3: >6 h(n = 15). Left atrial(LA) maximal volume(V_max), atrial precontraction volume(V_apc), minimal volume(V_min), LAEF, and PALS/PACS were all increasingly worsened among the patients in the 3 groups (p value for trend <0.05). Compared to Group 1, Group 2 had decreased LA PALS/PACS. There was no significant difference in LA volume or EF between Group 1 and 2. Group 3 had enlarged biatrial volumes (LAV_max: 57.1(SD 16.0) vs. 45.4(SD 9.2) mL/m², p = 0.002; LAV_min: 42.6(SD 18.2) vs. 28.2(SD 7.2) mL/m², p < 0.001), impaired total LAEF (28.0(SD 13.7) vs. 38.2(SD 7.7)%, p = 0.004) and reduced PALS/PACS compared to Group 1. Atrial remodeling in those with AHRE >6 h had increased LA volumes, impaired LAEF and reduced PALS/PACS compared to those with AHRE <6 h.

CONCLUSION

Functional remodeling of the atria manifested after AHRE >6 min. Increased biatrial volumes and decreased LA reservoir and pump function occurred when AHRE were > 6 h. These LA structural and functional may be considered surrogate imaging markers for stroke risk assessment in patients with CHA₂DS₂-VASc ≥2 and AHRE.

Deep learning-based automatic left atrial appendage filling defects assessment on cardiac computed tomography for clinical and subclinical atrial fibrillation patients

Rationale and objectives

Selecting region of interest (ROI) for left atrial appendage (LAA) filling defects assessment can be time consuming and prone to subjectivity. This study aimed to develop and validate a novel artificial intelligence (AI), deep learning (DL) based framework for automatic filling defects assessment on CT images for clinical and subclinical atrial fibrillation (AF) patients.

Materials and methods

A total of 443,053 CT images were used for DL model development and testing. Images were analyzed by the AI framework and expert cardiologists/radiologists. The LAA segmentation performance was evaluated using Dice coefficient. The agreement between manual and automatic LAA ROI selections was evaluated using intraclass correlation coefficient (ICC) analysis. Receiver operating characteristic (ROC) curve analysis was used to assess filling defects based on the computed LAA to ascending aorta Hounsfield unit (HU) ratios.

Results

A total of 210 patients (Group 1: subclinical AF, n = 105; Group 2: clinical AF with stroke, n = 35; Group 3: AF for catheter ablation, n = 70) were enrolled. The LAA volume segmentation achieved 0.931-0.945 Dice scores. The LAA ROI selection demonstrated excellent agreement (ICC ≥0.895, p < 0.001) with manual selection on the test sets. The automatic framework achieved an excellent AUC score of 0.979 in filling defects assessment. The ROC-derived optimal HU ratio threshold for filling defects detection was 0.561.

Conclusion

The novel AI-based framework could accurately segment the LAA region and select ROIs while effectively avoiding trabeculae for filling defects assessment, achieving close-to-expert performance. This technique may help preemptively detect the potential thromboembolic risk for AF patients.

Atrial cardiomyopathy: Diagnosis, clinical implications and unresolved issues in anticoagulation therapy

Atrial cardiomyopathy (AC) is an evolving pathophysiological entity that has expanded our understanding regarding the atrium and its role in arrhythmogenesis and cardiac thromboembolism. The pathological myocardium in AC promotes arrhythmogenesis through mechanical dysfunction (hypocontractility, fibrosis), adverse alterations of the endothelium and secretion of prothrombotic factors (IL-6, IL-8, TNF-a). 'Red flags', indicative of AC, can be recognized either non-invasively by electrocardiography, echocardiography and cardiac magnetic resonance imaging or invasively by high-density electroanatomical mapping as low bipolar voltage areas of the affected myocardium. Signs of AC have been strongly associated with an increased risk of ischemic stroke, even embolic strokes of undetermined source, regardless of the coexistence of atrial fibrillation (AF). The underlying existence of AC has been negatively correlated with the success rate of catheter ablation of AF. The clinical value of AC is the provision of a novel pathway regarding the potential mechanisms of cerebrovascular events of cardiac thromboembolic origin. In addition, AC may serve as a risk stratification tool to predict the long-term responders of AF catheter ablation.

Severe Left Atrial Spontaneous Echo Contrast in Nonvalvular Atrial Fibrillation: Clinical Characteristics and Impact on Ischemic Risk Postablation

BACKGROUND

 Spontaneous echo contrast (SEC) is an important precursor for intracardiac thrombus and stroke. There are very limited data on characteristics of severe SEC and its impact on ischemic risk of nonvalvular atrial fibrillation (NVAF) patients after radiofrequency catheter ablation.

METHODS

 Transesophageal echocardiography files were reviewed between March 2009 and March 2021 in this monocentric retrospective study. SEC was classified into four levels. The primary endpoint was thromboembolic event (stroke, myocardial infarction, systemic embolism, and ensuing death), and the secondary endpoint included nonischemic mortality and recurrent atrial arrhythmia.

RESULTS

 Six hundred SEC cases were enrolled and classified into mild SEC group (Grade 1-2, n = 515) and severe SEC group (Grade 3-4, n = 85). Independent risk factors for severe SEC included higher brain natriuretic peptide (BNP), erythrocyte sedimentation rate (ESR), and LAd/∆LVED (LAd = left atrial diameter; ∆LVED = left ventricular end-diastolic diameter - left ventricular end-systolic diameter). The severe SEC group had a higher peri-procedural ischemic event occurrence (7.1 vs. 1.9%, p = 0.007). At a median follow-up of 55 months, the severe SEC group had a lower freedom rate from ischemic events (90.1 vs. 75.3%, p < 0.001); older age and severe SEC were independent risk factors for ischemic events. In patients undergoing redo-procedure (n = 100), a remarkably reduced ESR (17.8 ± 12.0 vs. 28.2 ± 19.0 mm/h, p < 0.001) was observed in patients whose SEC disappeared.

CONCLUSIONS

 Higher BNP, ESR, and LAd/∆LVED were the independent predictors for severe SEC. Severe SEC was associated with higher peri-procedural and long-term ischemic risks. ESR and LAd/∆LVED, as indicators of hematological and hemodynamic change, seemed helpful in identifying NVAF patients prone to developing severe SEC.

Association between four-dimensional echocardiographic left atrial measures and left atrial fibrosis assessed by left atrial late gadolinium enhancement

AIMS

Left atrial (LA) fibrosis is a hallmark of atrial cardiomyopathy, and non-invasive surrogate measures of LA fibrosis are therefore needed. We investigated the association between four-dimensional (4D) echocardiographic LA measures and LA fibrosis.

METHODS AND RESULTS

A multimodality imaging substudy was performed in a randomized clinical trial (LOOP study), recruiting elderly participants with cardiovascular risk factors. LA late gadolinium enhancement (LGE) by cardiac magnetic resonance imaging was used as a surrogate for LA fibrosis. 4D echocardiographic LA quantification was used to measure maximal and minimal LA volume (LAVmax and LAVmin, respectively), LA emptying fractions (LAEFtotal), and strain. Logistic regression was used to relate LA measures to high LA LGE (≥17 cm2). Of the 44 participants (mean age 76 years, 64% men, median LA LGE 13.1 cm2), 14 exhibited high LA LGE. These participants exhibited abnormalities in several LA functional measures but not LAVmax. In linear regressions, only increasing LAVmin, and decreasing LAEFtotal, and reservoir strain were associated with increasing LA LGE. Furthermore, increasing LAVmin was associated with a higher likelihood of high LA LGE [odds ratio (OR) = 1.19 (1.04-1.37)]. Decreasing LAEFtotal and reservoir strain were also associated with higher likelihood of LA LGE [OR = 1.18 (1.05-1.33)] and OR = 1.15 (1.02-1.30), per 1% decrease in LAEFtotal and reservoir strain, respectively]. These findings were consistent after multivariable adjustments. LAEFtotal provided the highest performance for detecting high LA LGE (area under the curve of 0.78).

CONCLUSION

LAVmin, LAEFtotal, and reservoir strain measured by 4D echocardiography are significantly associated with LA LGE. LAEFtotal provides the best performance for detecting high LA LGE.

Circulating fibroblast activation protein α is reduced in acute ischemic stroke

Background

Fibroblast activation protein α (FAP), a membrane glycoprotein with dipeptidyl-peptidase and collagenase properties, is expressed in atherosclerotic plaques and remodeling of the extracellular matrix based on fibrosis. Fibrosis is a main contributor of atrial cardiomyopathies. In acute MI, circulating FAP is associated with outcome. Here, we investigated the correlation of circulating FAP to echocardiographic parameters of atrial remodeling and neurological impairment in acute ischemic stroke.

Methods

Circulating FAP plasma concentrations were determined by ELISA in 47 patients with acute stroke and 22 control patients without stroke. Echocardiography was performed in all participants. Laboratory analysis, National Institutes of Health Stroke Scale (NIHSS) scoring and prolonged Holter-ECG-monitoring were performed in all stroke patients.

Results

Patients with acute stroke had lower circulating FAP concentrations than the control cohort (92 ± 24 vs. 106 ± 22 ng/mL, P < 0.001). There was no difference between the circulating FAP concentration comparing stroke due to atrial fibrillation, embolic stroke of undetermined source (ESUS) or atherosclerotic origin. Septal atrial conduction time (sPA-TDI) and left atrial (LA) volume index to tissue Doppler velocity (LAVI/a') representing echocardiographic parameters of LA remodeling did not correlate with FAP concentrations (sPA-TDI: r = 0.123, p = 0.31; LAVI/a': r = 0.183, p = 0.132). Stroke severity as assessed by NIHSS inversely correlated with circulating FAP (r = -0.318, p = 0.04). FAP concentration had a fair accuracy for identifying stroke in the receiver operating characteristic (ROC) analysis (AUC = 0.710, 95% CI: 0.577-0.843). A FAP concentration of 101 ng/mL discriminated between presence and absence of stroke with a sensitivity of 72% and a specificity of 77%. Lower circulating FAP concentration was associated with cardio-cerebro-vascular events within 12 months after admission.

Conclusions

Our study is the first to associate FAP with echocardiographic parameters of LA-remodeling and function. FAP did not correlate with sPA-TDI and LAVI/a'. However, FAP was associated with stroke, neurological impairment, and cardio-cerebral events within 12 months. Therefore, FAP might enable individualized risk stratification in ischemic stroke.

Preprocedural Multimodality Imaging in Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia worldwide and is associated with increased risk of heart failure, stroke, and death. In current medical practice, multimodality imaging is routinely used in the management of AF. Twenty-one years ago, the ACUTE trial (Assessment of Cardioversion Using Transesophageal Echocardiography) results were published, and the management of AF changed forever by incorporating transesophageal echocardiography guided cardioversion of patients in AF for the first time. Current applications of multimodality imaging in AF in 2022 include the use of transesophageal echocardiography and computed tomography before cardioversion to exclude left atrial thrombus and in left atrial appendage occlusion device implantation. Transesophageal echocardiography, cardiac computed tomography, and cardiac magnetic resonance are clinically used for AF ablation planning. The decision to use a particular imaging modality in AF is based on patient's characteristics, guideline recommendation, institutional preferences, expertise, and cost. In this first of 2-part review series, we discuss the preprocedural role of echocardiography, computed tomography, and cardiac magnetic resonance in the AF, with regard to their clinical applications, relevant outcomes data and unmet needs, and highlights future directions in this rapidly evolving field.