Left and right atrial appendage functional features as predictors for voltage-defined left atrial remodelling in patients with long-standing persistent atrial fibrillation

The association between left atrial appendage emptying velocity and atrial fibrillation recurrence after radiofrequency catheter ablation in patients with early persistent atrial fibrillation

OBJECTIVE

In the present study, we aimed to explore the association between left atrial appendage emptying velocity (LAAEV) measured by transesophageal echocardiography and atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA) in patients with early persistent atrial fibrillation (PeAF).

METHODS

We retrospectively analyzed patients with early PeAF who underwent their initial ablation procedure. The echocardiographic and clinical data of the enrolled patients were collected and recorded prior to the operation. Following adjustment for confounding factors, we investigated the relationship between the LAAEV and AF recurrence in patients with early PeAF after radiofrequency ablation.

RESULTS

The proportions of AF recurrence in the low, medium, and high LAAEV groups were 48.8%, 16.0%, and 13.1%, respectively. After adjusting for potential confounding factors, we observed a gradual decrease in the risk of AF recurrence with increasing LAAEV (odds ratio: 0.882, 95% confidence interval: 0.842-0.924, p<0.001). This trend was statistically significant (p<0.001), particularly when comparing the high and low LAAEV groups (odds ratio: 0.033, 95% confidence interval: 0.009-0.116, p<0.001). Curve fitting analysis demonstrated an approximate negative linear association between LAAEV and the probability of AF recurrence.

CONCLUSIONS

Among patients with early PeAF who successfully underwent their first RFCA, we found that the LAAEV within 24 h before the procedure was independently correlated with the risk of AF recurrence. Notably, this association was negative, indicating that higher LAAEV was associated with a lower risk of AF recurrence.

Influencing factors and predictive model for left atrial appendage emptying velocity in nonvalvular AF patients

Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia, significantly increasing the risk of death and stroke. The left atrial appendage (LAA) plays a crucial role in the development of AF. Reduced left atrial appendage emptying velocity (LAAEV) is an important indicator of nonvalvular AF, associated with thrombosis and recurrence after catheter ablation. This study aims to identify factors influencing LAAEV and construct a predictive model for LAAEV in nonvalvular AF patients.

Methods

This retrospective cohort study included 1,048 nonvalvular AF patients hospitalized at the Second Hospital of Hebei Medical University from January 1, 2015, to December 31, 2021. Patients underwent transthoracic and transesophageal echocardiography and had complete laboratory data. Statistical analyses included binary logistic regression and multiple linear regression to identify independent predictors of reduced LAAEV and construct a predictive model.

Results

Patients were divided into two groups: reduced LAAEV (<40 cm/s) and normal LAAEV (≥40 cm/s). The reduced LAAEV group included 457 patients (43.61%), with significant differences in age, gender, alcohol consumption, heart failure (HF), ischemic stroke, AF type, resting heart rate, CHA2DS2-VASc score, serum creatinine (SCR), serum uric acid (SUA), estimated glomerular filtration rate (eGFR), glycated hemoglobin (HbA1C), β2 macroglobulin (B2M), left atrial diameter (LAD), and left ventricular ejection fraction (LVEF) compared to the normal LAAEV group. Logistic regression analysis identified age (OR 0.974, 95% CI 0.951-0.997, P = 0.028), HF (OR 0.637, 95% CI 0.427-0.949, P = 0.027), AF type [Persistent AF vs. PAF (OR 0.063, 95% CI 0.041-0.095, P = 0) Long-standing Persistent AF vs. PAF (OR 0.077, 95% CI 0.043-0.139, P = 0)], LAD (OR 0.872, 95% CI 0.836-0.91, P < 0.001), and LVEF (OR 1.057, 95% CI 1.027-1.089, P = 0) as independent predictors of reduced LAAEV. Multiple linear regression analysis included age, AF type, LAD, and LVEF in the final predictive model, explaining 43.5% of the variance in LAAEV (adjusted R² = 0.435).

Conclusion

Age, HF, type of AF, LAD, and LVEF are independent predictors of reduced LAAEV. The predictive model (LAAEV = 96.567-15.940 × AFtype-1.309 × LAD-0.18 × Age + 37.069 × LVEF) demonstrates good predictive value, aiding in the initial assessment and management of nonvalvular AF patients.

Left atrial appendage doppler velocity as a predictor of recurrence of atrial fibrillation after transesophageal echocardiogram guided electrical cardioversion

Background

There is a paucity of data on average left atrial appendage emptying velocity (LAAV) measured by doppler during transesophageal echocardiogram (TEE) being able to predict the risk of AF recurrence after electrical cardioversion (ECV).

Methods

Using electronic medical records from a community hospital, retrospective study was conducted after identifying all patients that received TEE-guided ECV. Data pertaining to LAAV, AF recurrence, and variables were obtained and analyzed.

Results

Out of 625 patients receiving TEE-guided ECV, 94 were excluded, and 51 did not convert to sinus rhythm. 480 patients had a successful ECV; out of these, 201 (41.87%) and 243 (50.62%) had a recurrence of atrial fibrillation at the end of 1 month and 3 months, respectively. Low LAAV (<=30 cm/s) was independently associated with an increased risk of AF recurrence at the end of 1 month (aOR 2.37, 95CI 1.5-3.73; p < 0.001) and 3 months (aOR 2.51, 95CI 1.59-3.96; p < 0.001) after TEE-guided ECV.

Conclusions

Low LAAV is associated with a high risk of AF recurrence. Identifying a specific subgroup of individuals at high risk of AF recurrence with the help of pre-ECV LAAV will facilitate the early institution of alternate treatment strategies and the plan for additional therapies.

ECGI targeted ablation for persistent AF not responding to pulmonary vein isolation: Results of a two-staged strategy (TARGET AF2)

Background

Mechanisms sustaining persistent atrial fibrillation (AF) remain unclear.

Objectives

The study sought to evaluate both the clinical outcomes and response to ablation of potential drivers in patients with recurrent persistent AF recurrence following pulmonary vein isolation (PVI).

Methods

A total of 100 patients with persistent AF of <2 years' duration underwent cryoballoon PVI (ECGI phenotyping of persistent AF based on driver burden and distribution to predict response to pulmonary vein isolation). Patients with documented recurrence of atrial arrhythmia within 12 months were recruited and underwent repeat PVI (if needed) followed by ablation of potential drivers (PDs) identified by electrocardiographic imaging (ECGI). PDs were defined as rotational activity >1.5 revolutions or focal activations. Cycle lengths were measured pre- and postablation. The primary outcome was freedom from atrial arrhythmia off antiarrhythmic drugs at 1 year as per guidelines.

Results

Of 37 patients recruited, 26 had recurrent AF and underwent ECGI-guided ablation of PDs. An average of 6.4 ± 2.7 PDs were targeted per patient. The mean ablation time targeting PDs was 15.5 ± 6.9 minutes. An ablation response occurred in 20 patients (AF termination in 6, cycle length prolongation ≥10% in 14). At 1 year, 14 (54%) of 26 patients were free from arrhythmia, and 12 (46%) of 26 were off antiarrhythmic drugs. Considering the 96 patients who completed follow-up out of the original cohort of 100 patients undergoing cryoablation in this staged strategy, freedom from arrhythmia at 1 year following the last procedure was 72 (75%) of 96, or 70 (73%) of 96 off antiarrhythmic drugs.

Conclusions

In patients with recurrent AF despite PVI, ECGI-guided ablation caused an acute response in a majority with reasonable long-term outcomes.

Does left atrial appendage morphology and dimension differ amongst etiological stroke subtypes in patients without known atrial fibrillation? Results from the left atrial appendage morphology and dimension assessment by TEE in patients with stroke without known atrial fibrillation (LAMDA-STROKE) study

CONTEXT

Complex left atrial appendage (LAA) morphology is increasingly associated with cryptogenic ischemic stroke as compared to cardioembolic stroke due to atrial fibrillation (AF). However, data on such an association in patients with other etiological stroke subtypes in the absence of AF is limited.

AIM

The study aimed to assess the LAA morphology, dimension and other echocardiographic parameters by transesophageal echocardiography (TEE) in patients with embolic stroke of undetermined source (ESUS) and compare it with other etiological stroke subtypes without known AF.

METHODS

This was a single-Centre, observational study involving comparison of echocardiographic parameters including LAA morphology and dimension in ESUS patients (group A; n = 30) with other etiological stroke subtypes i.e., TOAST (Trial of Org 10172 in Acute Stroke Treatment) class I-IV without AF (group B; n = 30).

RESULTS

Complex LAA morphology was predominant in group A (18 patients in group A versus 5 patients in group B, p-Value = 0.001). Mean LAA orifice diameter (15.3 + 3.5 mm in group A versus 17 + 2.0 mm in group B, p-Value = 0.027) and LAA depth were significantly lower in group A (28.4 + 6.6 mm in group A versus 31.7 + 4.3 mm in group B, p-Value = 0.026). Out of these three parameters only complex LAA morphology was found to be independently associated with ESUS [OR = 6.003, 95% CI {1.225-29.417}, p = 0.027].

CONCLUSION

Complex LAA morphology is a predominant feature in ischemic stroke patients with ESUS and may contribute to an increased risk of stroke in these patients.

Echocardiographic evaluation of the right atrial size and function: Relevance for clinical practice

Right atrial (RA) structural and functional evaluations have recently emerged as powerful biomarkers for adverse events in various cardiovascular conditions. Quantitative analysis of the right atrium, usually performed with volume changes or speckle-tracking echocardiography (STE), has markedly changed our understanding of RA function and remodeling. Knowledge of reference echocardiographic values and measurement methods of RA volumes and myocardial function is a prerequisite to introduce RA quantitation in the clinical routine. This review describes the methodology, benefits and pitfalls of measuring RA size and function by echocardiography based on the current understanding of right atrial anatomy and physiological function and provides the current knowledge of right atrial function in related cardiac diseases.

Left atrial appendage flow velocity predicts recurrence of atrial fibrillation after catheter ablation: A systematic review and meta-analysis

Purpose

There is increasing evidence that left atrial appendage flow velocity (LAAFV) is linked to the recurrence of atrial fibrillation (AF) after catheter ablation (CA), suggesting the potential predictable significance of LAAFV in this setting. We performed a systematic review and meta-analysis to assess whether LAAFV is association with AF recurrence after CA.

Methods

Up to May 1, 2022, six databases (PubMed, EMBASE, Web of Science, Cochrane Library, Scopus, and CINAHL) were searched for literature reporting the association between LAAFV and AF recurrence after CA. All statistical analyses were carried out using STATA version 16 software. Heterogeneity was determined by the Cochrane’s Q test and I² statistics. The Newcastle-Ottawa Scale (NOS) was used to assess the methodological quality of each included study, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) method was adopted to evaluate the quality of evidence.

Result

Sixteen studies with 5,006 AF patients after CA (1,479 patients with AF recurrence, 3,527 without AF recurrence) were included in the meta-analysis. The meta-analysis of 15 studies (16 data sets) showed that patients with recurrence exhibited lower LAAFV values than those without recurrence [standardized mean difference (SMD): −0.65, 95% CI: −0.88 to −0.42, P < 0.01]. Moreover, we evaluated the association of LAAFV and the risk of AF recurrence after CA. Nine studies (11 data sets) defined LAAFV as continuous variables, and the pooled analysis suggested that for every 1 cm/s rise in LAAFV values, the risk of AF recurrence after CA decreased by 3% [Odds Ratio (OR): 0.97, 95% CI: 0.95 to 0.99, P < 0.01]. Seven studies defined LAAFV as categorical variables, and the pooled analysis showed that lower LAAFV were associated with an increased risk of AF recurrence after CA [OR: 2.28, 95% CI: 1.46 to 3.57, P < 0.01]. The subgroup analyses showed that the association between LAAFV and AF recurrence after CA was not significantly affected by the AF type and ablation procedure. The NOS indicated that included studies were moderate to high quality, while the GRADE assessment suggested a low certainty of the evidence.

Conclusion

Lower LAAFV may be associated with an increased risk of AF recurrence after CA. Further studies with well designed and randomized studies for LAAFV should be conducted.

Systematic review registration

[https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42022333627].

Left atrial epicardial adipose tissue is closely associated with left atrial appendage flow velocity in patients with nonvalvular atrial fibrillation

Epicardial adipose tissue (EAT) can play an important role in the occurrence and development of atrial fibrillation and stroke. In this study, we explored the relationship between left atrial epicardial adipose tissue (LA-EAT) and left atrial appendage flow velocity (LAA-FV) in patients with nonvalvular atrial fibrillation (NV-AF). A total of 145 patients with NV-AF who underwent their first radiofrequency ablation were enrolled. They underwent left aortopulmonary vein computed tomography angiography (CTA) and transesophageal echocardiography (TEE) before AF ablation. Left atrial (LA) electroanatomical mapping was performed intraoperatively to assess left atrial voltage. Univariate regression analysis showed that LAA-FV was lower in patients with a low voltage zone (LAA-FV; 35.02 ± 10.78 cm/s vs. 50.60 ± 12.17 cm/s, P < 0.001). A multiple linear regression model showed that the left atrial low voltage zone (β = - 0.311 P < 0.001), LA-EAT volume (β = - 0.256 P < 0.001), left atrial appendage shape (β = - 0.216 P = 0.041), LAVI (β = - 0.153 P = 0.041), and type of atrial fibrillation (paroxysmal vs. persistence) (β = - 0.146 P < 0.048) were independent predictors of LAA-FV. In NV-AF patients, the increase in LA-EAT volume is related to the decrease in LAA-FV.

The prognostic significance of left atrial appendage peak flow velocity in the recurrence of persistent atrial fibrillation following first radiofrequency catheter ablation

Background

Atrial fibrillation (AF) relapse following radiofrequency catheter ablation (RFCA) for persistent atrial fibrillation (PeAF) continues to be a concern. This study establishes a connection between left atrial appendage peak flow velocity (LAAV) and recurrence of AF in individuals having PeAF following first RFCA.

Methods

We retrospectively studied 164 successive PeAF patients who had first RFCA between January 2018 and December 2019. Before the ablation, the LAAV was recorded using transesophageal echocardiography (TEE). The demographic and clinical data of the individuals were gathered. Participants were monitored at regular intervals to monitor for recurrence of AF. We employed Cox proportional hazards regression to determine if LAAV, as well as other clinical indicators, were predictive of AF recurrence in follow-up.

Results

In this study, AF relapse was seen in 43 patients (26.2%) following a median follow-up of 15 [interquartile range (IQR): 12–18] months. It was shown that the LAAV was decreased in individuals who had recurrences of AF (0.36±0.05 vs. 0.45±0.17 m/s, P=0.004). Using Kaplan-Meier analysis, it was discovered that the low LAAV (0.37 m/s) group had a poorer event-free survival rate compared to the high LAAV (>0.37 m/s) group (17.6 vs. 21.2 months, log-rank P=0.002) group. Based on the results of the multivariate Cox regression analysis, a LAAV of fewer than 0.37 m/s [hazard ratio (HR): 2.32; 95% confidence interval (CI): 1.177–4.227; P=0.014] was shown to be an independent predictor of AF recurrence following RFCA.

Conclusions

A low LAAV is associated with AF relapse, and it is a predictor of AF relapse following the first RFCA for PeAF. This discovery may be useful in the optimization of treatment strategies and the care of patients with PeAF.

Effect of Sox9 on TGF-β1-mediated atrial fibrosis

Atrial fibrosis is a crucial mechanism responsible for atrial fibrillation (AF). Sex-determining region Y-box containing gene 9 (Sox9) plays a pivotal role in fibrosis of many organs such as the skin, kidney, and liver. However, there are few studies about the occurrence and maintenance of Sox9 in atrial fibrosis. In this study, we investigated the role of Sox9 in the fibrotic phenotype of human atrial tissues and rat atrial fibroblasts in vitro. In the human right atrial tissue, Masson's trichrome staining, immunofluorescence, real-time quantitative polymerase chain reaction, and western blot analysis were carried out to explore the relationship between Sox9 and atrial fibrosis at the morphological, functional, and molecular levels. In cultured atrial fibroblasts, Sox9 was overexpressed by adenovirus or depleted by siRNA, and then, recombinant human transforming growth factor (TGF)-β1 was added. Immunofluorescence analysis, western blot analysis, Transwell assay, and scratch assay were used to analyze the cells. In patient atrial tissues, Sox9 was increased with worsened atrial fibrosis, and this increase was related to AF severity. In rat atrial fibroblasts, Sox9 was promoted by TGF-β1, and the α-smooth muscle actin (α-SMA) protein level and the ability of cell migration were increased after Sox9 overexpression by adenovirus, while the α-SMA protein level and the cell migration ability were decreased after Sox9 depletion by siRNA. In conclusion, Sox9 is involved in the regulation of fibrosis in the atria and may be located downstream of TGF-β1. Our findings may provide a new perspective to treat atrial fibrosis during AF.