Low left atrial appendage flow velocity predicts recurrence of atrial fibrillation after catheter ablation of persistent atrial fibrillation

Left atrial appendage peak flow velocity predicts improvement in mitral regurgitation after atrial fibrillation ablation

BACKGROUND

Mitral regurgitation (MR) is associated with an increased risk of developing atrial fibrillation (AF) and high AF recurrence ratio after ablation. Left atrial appendage (LAA) is involved in left atrium (LA) pressure modulation and LAA peak flow velocity (LAAV) is validated as an indicator of LA contractile and reservoir function. LA function is related to the MR pathology, but the relationship between LAAV and improvement in MR after ablation remains unknown.

METHODS

The present study included AF patients with moderate or severe MR from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry. We evaluated MR severity one-year post-ablation and assigned the patients based on MR improvement (at least a one-grade improvement in MR over one year) and investigated the impact of the relevant factors, including LAAV, on MR improvement.

RESULTS

This study population included a total of 289 patients [paroxysmal AF (PAF), 112 patients; persistent AF (PerAF), 177 patients]. Kaplan-Meier analysis demonstrated that the patients with MR improvement had a significantly lower risk of late arrhythmia recurrence than those without (log-rank p < 0.001). MR improvement was observed in 56.3 % (63/112) of PAF patients and 55.4 % (98/177) of PerAF patients. Multiple regression analysis showed that LAAV was an independent and significant determinant of MR improvement post-ablation in both PAF and PerAF patients (p = 0.037 and p = 0.018, respectively), in addition to age and hemoglobin in PerAF patients (p = 0.045 and p = 0.048, respectively).

CONCLUSION

LAAV can predict an improvement in MR after catheter ablation in both PAF and PerAF patients.

Clinical Implication of Left Atrial Appendage Emptying Velocity in Thoracoscopic Ablation of Atrial Fibrillation

BACKGROUND

There are limited data about predictors of atrial fibrillation (AF) recurrence after totally thoracoscopic ablation (TTA). This study investigated the clinical implication of left atrial appendage emptying velocity (LAAV) in patients undergoing TTA.Methods and Results: Patients who underwent TTA between 2012 and 2015 at a tertiary hospital were prospectively enrolled in this study. LAAV was measured and averaged over five heart beats from preoperative transesophageal echocardiography. The primary outcome was a freedom from recurrent AF or atrial flutter (AFL) detected on 24-h Holter monitoring or an electrocardiogram over a 3-year period after TTA. In all, 129 patients were eligible for analysis in this study. The mean (±SD) patient age was 54.4±8.8 years, and 95.3% were male. During the 3 years after TTA, the overall event-free survival rate was 65.3%. LAAV was an independent predictor of recurrent AF/AFL during the 3-year period after TTA (per 1-cm/s increase, adjusted hazard ratio [aHR] 0.95; 95% confidence interval [CI] 0.91-0.99; P=0.016). Event-free survival was significantly lower among patients with a low LAAV (<20 cm/s; n=21) compared with those with a normal (≥40 cm/s; n=38; aHR 6.11; 95% CI 1.42-26.15; P=0.015) or intermediate (LAAV ≥20 and <40 cm/s; n=70; aHR 2.74, 95% CI 1.29-5.83; P=0.009) LAAV.

CONCLUSIONS

In patients with AF, LAAV was significantly associated with the risk of long-term recurrence of AF after TTA.

Impact of pre-ablation left appendage flow velocities on long term recurrence of catheter ablation for paroxysmal atrial fibrillation

BACKGROUND

Despite undergoing a single ablation, many patients with paroxysmal atrial fibrillation (PAF) experience a gradually increasing recurrence rate. This study aims to examine the relationship between left atrial appendage emptying velocity (LAAeV) and filling velocity (LAAfV) profiles and 3-year recurrence of AF after ablation.

METHODS

We conducted a prospective study of 658 consecutive PAF patients who underwent their first ablation between January 2018 and December 2019. We collected the clinical and echocardiographic characteristics of the patients. LAAeV and LAAfV were obtained from a transesophageal echocardiogram (TEE) before catheter ablation. Patients were followed at regular intervals to monitor for the primary outcome of AF recurrence.

RESULTS

After a median follow-up period of 35.3 months (range, 10.7-36.3), 288 patients (43.8%) experienced AF recurrence after catheter ablation. Patients who experienced AF recurrence had decreased LAAeV and LAAfV (LAAeV: 56.5 ± 21.2 vs. 59.6 ± 20.7 cm/s, p = .052; LAAfV: 47.5 ± 17.9 vs. 51.7 ± 18.2, p = .003). Kaplan-Meier analysis showed that patients in the low LAAeV (<55 cm/s) group had a poorer event-free survival rate than those in the high LAAeV (≥55 cm/s) group (log-rank p = .012). Patients with LAAfV <48 cm/s had a significantly higher risk of AF recurrence than those with LAAfV ≥48 cm/s (log-rank p = .003). In the multivariable model, low LAAfV pre-ablation in TEE-guided was significantly independently associated with 3-year recurrence after single radiofrequency ablation in patients with PAF, along with LA dimension and duration of AF.

CONCLUSION

This study found an independent association between low LAAfV pre-ablation in TEE-guided and 3-year recurrence after single radiofrequency ablation in patients with PAF.

Incremental predictive utility of a radiomics signature in a nomogram for the recurrence of atrial fibrillation

Background

Recurrence of atrial fibrillation (AF) after catheter ablation (CA) remains a challenge today. Although it is believed that evaluating the structural and functional remodeling of the left atrium (LA) may be helpful in predicting AF recurrence, there is a lack of consensus on prediction accuracy. Ultrasound-based radiomics is currently receiving increasing attention because it might aid in the diagnosis and prognosis prediction of AF recurrence. However, research on LA ultrasound radiomics is limited.

Objective

We aim to investigate the incremental predictive utility of LA radiomics and construct a radiomics nomogram to preoperatively predict AF recurrence following CA.

Methods

A training cohort of 232 AF patients was designed for nomogram construction, while a validation cohort (n = 100) served as the model performance test. AF recurrence during a follow-up period of 3-12 months was defined as the endpoint. The radiomics features related to AF recurrence were extracted and selected to create the radiomics score (rad score). These rad scores, along with other morphological and functional indicators for AF recurrence, were included in the multivariate Cox analysis to establish a nomogram for the prediction of the likelihood of AF recurrence within 1 year following CA.

Results

In the training and validation cohorts, AF recurrence rates accounted for 32.3% (75/232) and 25.0% (25/100), respectively. We extracted seven types of radiomics features associated with AF recurrence from apical four-chamber view echocardiography images and established a rad score for each patient. The radiomics nomogram was built with the rad score, AF type, left atrial appendage emptying flow velocity, and peak atrial longitudinal strain. It outperformed the nomogram building without the rad score in terms of the predictive efficacy of CA outcome and showed favorable performance in both cohorts.

Conclusion

We revealed the incremental utility of a radiomics signature in the prediction of AF recurrence and preliminarily developed and validated a radiomics nomogram for identifying patients who were at high risk of post-CA recurrence, which contributed to an appropriate management strategy for AF.

Value of Left Atrial Strain in Predicting Recurrence after Atrial Fibrillation Ablation

This study tested the relationship between left atrial (LA) function parameters and the results of pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). Consecutive patients undergoing PVI for the first time between 2019 and 2021 were included. Patients underwent radiofrequency ablation using contact force catheters and an electroanatomical system. Follow-up consisted of ambulatory visits/televisits and 7-day Holter monitoring (at 6 and 12 months after ablation). On the day of ablation, all patients underwent transesophageal and transthoracic echocardiography with LA strain analysis. The primary endpoint was atrial tachyarrhythmia recurrence during the follow-up period. Of 221 patients, 22 did not meet the echocardiographic quality criteria, leaving 199 patients. The median follow-up period was 12 months, and 12 patients were lost to follow-up. Recurrences were observed in 67 patients (35.8%) after a mean of 1.06 procedures per patient. The patients were divided into a sinus rhythm (SR, n = 109) group and an AF (n = 90) group based on their cardiac rhythm at the time of echocardiography. In the SR group, univariable analysis showed that LA reservoir strain, LA appendage emptying velocity (LAAV), and LA volume index predicted AF recurrence, with only LAAV being significant in the multivariable analysis. In AF patients, univariable analysis revealed no LA strain parameters predicting AF recurrence.

Left Atrial Appendage Volume Predicts Atrial Fibrillation Recurrence after Radiofrequency Catheter Ablation: A Meta-Analysis

BACKGROUND

The influence of left atrial appendage volume (LAAV) on the recurrence of atrial fibrillation (AF) following radiofrequency catheter ablation remains unclear.

OBJECTIVES

We performed a meta-analysis to assess whether LAAV is an independent predictor of AF recurrence following radiofrequency catheter ablation.

METHODS

The PubMed and the Cochrane Library databases were searched until March 2022 to identify publications evaluating LAAV in association with AF recurrence after radiofrequency catheter ablation. Seven studies that fulfilled the specified criteria of our analysis were found. We used the Newcastle-Ottawa Scale to evaluate the quality of the studies. The pooled effects were evaluated depending on standardized mean differences (SMDs) or hazard ratios (HRs) with 95% confidence intervals (CIs). P values < 0.05 were considered statistically significant.

RESULTS

A total of 1017 patients from 7 cohort studies with a mean follow-up 16.3 months were included in the meta-analysis. Data from 6 studies (943 subjects) comparing LAAV showed that the baseline LAAV was significantly higher in patients with AF recurrence compared to those without AF (SMD: -0.63; 95% CI: -0.89 to -0,37; all p values < 0.05; I2= 62.6%). Moreover, higher LAAV was independently associated with a significantly higher risk of AF recurrence after radiofrequency catheter ablation (HR: 1.10; 95% CI: 1.02 to 1.18).

CONCLUSIONS

The meta-analysis showed that there is a significant correlation between LAAV and AF recurrence after radiofrequency catheter ablation, and the role of LAAV in AF patients should not be ignored in clinical practice.

Assessment of left atrial appendage function by echocardiography

The left atrial appendage (LAA) is considered not only to be the most frequent site of thrombus formation, but also to play a pivotal role in maintaining normal cardiac function. Transesophageal echocardiography (TEE) is widely used to assess LAA function. The LAA flow velocity has been used as a surrogate for LAA function, and it varies with multiple interrelated factors including age, hemodynamics, type of arrhythmia, and antiarrhythmic interventions. Relatively great importance of LAA function is involved with intraatrial thrombus formation and subsequent thromboembolism, and thus, understanding of characteristics and behaviors of the LAA under various clinical conditions may help determine strategies against atrial thrombosis. Also, techniques other than TEE-derived Doppler to assess LAA function, such as tissue Doppler imaging, have been proposed. In this review, we introduce clinical and echocardiographic correlates of LAA function, the LAA flow velocity in particular, its significance, and how to interpret functional patterns of the LAA each relevant to specific clinical settings.

Relationship between left atrial appendage peak flow velocity and nonvalvular atrial fibrillation recurrence after cryoablation

Background

Previous studies revealed the connection between left atrial appendage peak flow velocity (LAA-PEV) and postoperative persistent atrial fibrillation (AF) recurrence. Yet, this association is not necessarily generalizable to persistent AF patients undergoing initial cryoballoon ablation due to current gaps in the literature.

Methods

We prospectively studied 74 consecutive individuals with persistent atrial fibrillation undergoing a cryoballoon ablation for the first time between January 2018 and January 2020. Before ablation, LAA-PEV was documented by transesophageal echocardiography (TEE). Subsequently, demographic information and other clinical characteristics of these participants were collected. A 96-h continuous cardiac monitor was reviewed regularly for recurrence of atrial fibrillation. Cox proportional hazards regression was used to investigate LAA-PEV as well as other clinical characteristics as a predictor of AF recurrence.

Results

Our study found that AF recurrences had lower LAA-PEV than those without AF recurrence. A nonlinear relationship between the LAA-PEV and AF recurrence was observed in this study, which had an inflection point of 34.9. Subgroup analysis of female participants showed that LAA-PEV had a positive correlation with AF recurrence [β = 0.8, 95% CI (0.7, 0.9), p < 0.05].

Conclusion

A low LAA-PEV is related to recurrence of atrial fibrillation and may predict AF recurrence after initial cryoballoon ablation for persistent atrial fibrillation. This finding may help improve treatment and care strategies for patients with persistent atrial fibrillation.

Left atrial appendage function and structure predictors of recurrent atrial fibrillation after catheter ablation: A meta-analysis of observational studies

Background

The results of studies evaluating the left atrial appendage (LAA) function and structure as predictors of atrial fibrillation (AF) recurrence after catheter ablation (CA) are contradictory. Therefore, we performed a meta-analysis to assess whether the LAA function and structure can predict the recurrence of AF after CA.

Methods

The PubMed, EMBASE, Web of Science, and Cochrane library databases were used to conduct a comprehensive literature search. Finally, 37 studies encompassing 11 LAA parameters were included in this meta-analysis.

Results

Compared with those in the non-recurrence group, the recurrence group had increased LAA volume (SMD 0.53, 95% CI [0.36, 0.71] p < 0.00001), LAA volume index, LAA orifice area, and LAA orifice short/long axis and decreased LAA emptying flow velocity (SMD -0.54, 95% CI [-0.68, -0.40], P < 0.00001), LAA filling flow velocity, and LAA ejection fraction, while there was no significant difference in LAA morphology or LAA depth.

Conclusion

Large LAA structure of pre-ablation (LAA volume, orifice area, orifice long/short axis, and volume index) and decreased LAA function of pre-ablation (LAA emptying flow velocity, filling flow velocity, ejection fraction, and LASEC) increase the odds of AF recurrence after CA.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42022324533].

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].

Low Left Atrial Appendage Emptying Velocity is a Predictor of Atrial Fibrillation Recurrence After Catheter Ablation

BACKGROUND

Recurrence of atrial fibrillation (AF) after catheter ablation (CA) remains common and studies have shown about 5%-9% annual recurrence rate after CA. We sought to assess the echocardiogram derived left atrial appendage (LAA) emptying velocity as a predictor of AF recurrence after CA.

OBJECTIVE

To determine if LAA emptying is a marker of recurrence of AF post-CA METHODS: A total of 303 consecutive patients who underwent CA for AF between 2014 and 2020 were included. Baseline clinical characteristics and echocardiographic data of the patients were obtained by chart review. LAA emptying velocities were obtained from TEE. LA voltage was obtained during the mapping for CA. Chi-square test and nominal logistic regression were used for statistical analysis. An ROC curve was used to determine LAA velocity cut-off.

RESULTS

Mean patient age was 61.7±10.5; 32% were female. Mean LAA emptying velocity was 47.5±20.2. A total of 103 (40%) patients had recurrence after CA. In the multivariable model, after adjusting for potential confounders, LAA emptying velocity of ≥52.3 was associated with decreased AF recurrence post-ablation (OR 0.55; 95% CI: 0.31-0.97; p = 0.03*). There were 190 (73%) patients in normal sinus rhythm during TEE and CA, and sensitivity analysis of these patients showed that LAA velocity ≥52.3 remained associated with decreased AF recurrence (OR 0.35; 95% CI 0.15-0.82; p = 0.01*).

CONCLUSION

LAA emptying velocity measured during pre-procedural TEE can serve as a predictor of AF recurrence in patients undergoing CA. This article is protected by copyright. All rights reserved.

Machine Learning Model-Based Simple Clinical Information to Predict Decreased Left Atrial Appendage Flow Velocity

Background: Transesophageal echocardiography (TEE) is the first technique of choice for evaluating the left atrial appendage flow velocity (LAAV) in clinical practice, which may cause some complications. Therefore, clinicians require a simple applicable method to screen patients with decreased LAAV. Therefore, we investigated the feasibility and accuracy of a machine learning (ML) model to predict LAAV. Method: The analysis included patients with atrial fibrillation who visited the general hospital of PLA and underwent transesophageal echocardiography (TEE) between January 2017 and December 2020. Three machine learning algorithms were used to predict LAAV. The area under the receiver operating characteristic curve (AUC) was measured to evaluate diagnostic accuracy. Results: Of the 1039 subjects, 125 patients (12%) were determined as having decreased LAAV (LAAV < 25 cm/s). Patients with decreased LAAV were fatter and showed a higher prevalence of persistent AF, heart failure, hypertension, diabetes and stroke, and the decreased LAAV group had a larger left atrium diameter and a higher serum level of NT-pro BNP than the control group (p < 0.05). Three machine-learning models (SVM model, RF model, and KNN model) were developed to predict LAAV. In the test data, the RF model performs best (R = 0.608, AUC = 0.89) among the three models. A fivefold cross-validation scheme further verified the predictive ability of the RF model. In the RF model, NT-proBNP was the factor with the strongest impact. Conclusions: A machine learning model (Random Forest model)-based simple clinical information showed good performance in predicting LAAV. The tool for the screening of decreased LAAV patients may be very helpful in the risk classification of patients with a high risk of LAA thrombosis.

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.

Value of Left Atrial Appendage Function Measured by Transesophageal Echocardiography for Prediction of Atrial Fibrillation Recurrence after Radiofrequency Catheter Ablation

Atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA) remains a challenging issue. This study aims to explore the left atrial appendage function by transesophageal echocardiography (TEE) and assess its value in predicting AF recurrence following RFCA in paroxysmal AF patients. Eighty-one patients with paroxysmal AF that underwent RFCA were recruited. TEE was performed before ablation with the assessment of left atrial appendage emptying flow velocity (LAAeV). AF recurrence occurred in 24 patients (29.6%) within 12 months after RFCA. The left atrium diameter (LAD) and left atrium volume index (LAVI) were both significantly higher in the recurrence group compared to the non-recurrence group, while the LAAeV was significantly lower in the recurrence group. LAD, LAVi and LAAeV were univariately significant risk factors for AF recurrence after ablation. Based on receiver operating curve (ROC), LAAeV < 40.5 cm/s, LAVi > 40.5 mL and LAD > 41 mm were identified as cut-off values for predicting AF recurrence. In multivariate regression analysis LAAeV < 40.5 cm/s (HR 8.194, 95% CI 2.980–22.530, p < 0.001) was identified as the only statistically significant independent predictor of AF recurrence, as the statistical significance threshold was not achieved for LAVI > 40.5 mL and LAD > 41 mm (p = 0.319; p = 0.507, respectively). A low LAAeV was the only important independent predictor of AF recurrence within 1 year after first RFCA.

Incremental predictive value of left atrial strain and left atrial appendage function in rhythm outcome of non-valvular atrial fibrillation patients after catheter ablation

Objective

The purpose of this study was to develop a non-invasive and convenient nomogram based on speckle tracking echocardiography, left atrial appendage function and clinical factors to predict the risk of atrial fibrillation (AF) recurrence after catheter ablation.

Methods

A total of 124 prospectively consecutive patients with AF treated with catheter ablation in our hospital was retrospectively analysis. Baseline echocardiographic parameters were measured by using transthoracic and transesophageal echocardiography before ablation. Multivariate analysis was performed for selecting predictors for a nomogram and internal validation and calibration were evaluated by the bootstep method.

Results

During the follow-up of 12±3 months, 41 patients (33.1%) occurred AF recurrence after catheter ablation, while 83 patients (66.9%) had maintained sinus rhythm. Four predictors (AF type, left atrial appendage emptying flow velocity, left Atrial maximal volumes index and global longitudinal strain) with the P<0.5 was selected into the nomogram according to multivariate findings. Internal validation by bootstrapping with 1000 resamples was determined C-index of the nomogram for prediction AF recurrence was 0.901, which showed optimal discrimination and calibration of the established nomogram.

Conclusions

Nomogram based on echocardiography and clinical characteristics had good predictive performance for the possibility of AF recurrence, which providing practical guidance for individualised management of patients with AF after catheter ablation.

Atrial appendages’ mechanics assessed by 3D transoesophageal echocardiography as predictors of atrial fibrillation recurrence after pulmonary vein isolation

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Data on atrial appendages' mechanics as predictors of AF recurrence after PVI is scarce.

•

3D and 2D-TEE have potential to provide additional data on LAA function.

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Patients with AFR had significantly lower LAA tissue velocity and ostium surface area.

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RAA tissue velocity and SVC ostium surface area were not correlated to AF recurrence.

Background

Although there are numerous studies reflecting predictors of atrial fibrillation (AF) recurrence (AFR) after pulmonary vein isolation (PVI), data on atrial appendages' mechanics is scarce. This study aimed to assess atrial appendages' mechanics by 2-dimensional (2D) and 3-dimenssional (3D) transoesphageal echocardiography (TEE) and to explore its value to predict AFR after PVI.

Methods

Consecutive patients with paroxysmal AF undergoing first PVIwere analysed. 3D and 2D-TEE with tissue Doppler imaging (TDI) and strain analysis was obtained prior to the PVI, including: left atrial appendage (LAA) TDI and strain analysis, LAA ostium surface area, right atrial appendage’s TDI velocity and superior vena cava (SVC) ostium surface area. The primary end-point was freedom from any documented recurrence of atrial arrhythmia lasting > 30 s.

Results

This single-centre, prospective study included 74 patients with paroxysmal AF (median age 59 years; 36% female; BMI 27.4 ± 4.1 kg/m², LA volume index 32 ± 11 mL/m²). After a median follow-up of 14 (IQR 10–22) months, 21 (28%) patients had AFR. In a univariate and multivariate Cox-regression analysis LAA TDI velocity (HR 1.48, 95%CI 1.28–1.62, p < 0.001) and LAA ostium surface area(HR 1.58, 95%CI 1.06–1.81, p = 0.033) both independently predicted AFR after single PVI. RAA TDI velocity and SVC ostium surface area were not correlated to AFR.

Conclusion

Paroxysmal AF patients with lower LAA TDI tissue velocity and LAA ostium surface area have higher risk of developing AFR after PVI. To our knowledge, this is the first study assessing atrial appendages’ mechanics in predicting AFR after PVI.

Clinical trial registration: www.drks.de(Identifier: DRKS00010495)

The Predictive Value of Growth Differentiation Factor-15 in Recurrence of Atrial Fibrillation after Catheter Ablation

The mechanisms underlying the recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA) are not well concerned. The study sought to explore the association between growth differentiation factor-15 (GDF-15) and the incidence of recurrent events among AF patients after the ablation procedure. We prospectively included 150 consecutive AF patients who underwent RFCA. Clinical information about the patients was collected. Blood samples on the second morning of hospital admission and three months after RFCA were collected, and enzyme-linked immunosorbent assay (ELISA) was used to measure the concentration of GDF-15. All participants were followed up at specific times (1st/3rd/6th/12th/18th/24th months) after RFCA to record recurrences events. During a median follow-up of 14.0 months, AF recurrence occurred in 37(24.7%) patients. Baseline serum GDF-15 level in the persistent AF group was significantly higher than the paroxysmal AF group [1140(854~1701)ng/L vs. 1062(651~1374)ng/L, P = 0.039]. Baseline serum GDF-15 level in the recurrence group was significantly higher than the nonrecurrence group [1287(889~1768) ng/L vs. 1062(694~1373)ng/L, P = 0.022]. Serum GDF-15 level at three months after RFCA was significantly lower than the baseline [870 (579~1270) ng/L vs. 1155 (735~1632)ng/L, P < 0.001]. The baseline GDF-15 correlated significantly with LAP (r = 0.296, P < 0.001) and LAAV(r = −0.235, P = 0.003). Kaplan-Meier analysis showed a significantly lower event-free survival time in the high baseline GDF-15 (≥1287.3 ng/L) group than the low baseline GDF-15 (<1287.3 ng/L) group (17.1 months vs. 20.4 months, Log Rank P = 0.017). In the multivariate Cox regression, baseline GDF-15(HR 1.053, 95% CI 1.007-1.100, P = 0.022) and LAD (HR 1.124, 95% CI 1.011-1.250, P = 0.030) were independent predictors of AF recurrence after RFCA. Our study indicated increased preprocedural GDF-15 is associated with left atrial remodeling and acts as a predictor of AF recurrence after ablation.

Morphological and functional parameters of left atrial appendage play a greater role in atrial fibrillation relapse after radiofrequency ablation

This study was to quantitatively investigate the role of morphological and functional parameters of the left atrium (LA) and left atrial appendage (LAA) with 256-slice spiral computed tomography (CT) in the recurrence of atrial fibrillation (AF) after radiofrequency ablation (RFA). Eighty-three patients with AF who underwent RFA for the first time were divided into the recurrence (n = 27) and non-recurrence (n = 56) groups. All patients underwent a 256-slice spiral CT examination before the operation. The clinical data and quantitative measurement of the morphology and functional parameters of the LA and LAA were analyzed, including the maximal and minimal volume, ejection fraction and volume, and volume strain of LAA and LA (LAAVmax, LAAVmin, LAAEF, LAAEV, and LAA-VS, LAVmax, LAVmin, LAEF, LAEV and LA-VS, respectively). The CHA2DS2-VASc score and the proportion of patients with heart failure were significantly (P < 0.05) higher in the recurrence than non-recurrence group. The LAAVmax, LAAVmin, LAVmax, LAVmin, LAAV and LAV were all significantly greater in the recurrence than non-recurrence group (P < 0.05), and the perimeter, major and minor axes of LAA orifice and LAA depth were also significantly greater in the recurrence than non-recurrence group. The LAAEF, LAEF and LAA-VS were significantly (P < 0.05) lower in the recurrence than non-recurrence group (P < 0.05). Heart failure, CHA2DS2-VASC score, LAEF, LAV, LAAEF and LAA-VS were univariately significant (P < 0.05) risk factors for AF recurrence after ablation. Multivariate analysis revealed LAAEF (HR: 0.790, 95% CI: 0.657–0.950, P = 0.012) and LAAV (HR: 1.160, 95% CI: 1.095–1.229, P <0.001) to be two significant independent predictors of recurrence. ROC curve analysis showed that LAAEF <44.68% had the highest predictive value for recurrence after radiofrequency ablation, with the sensitivity of 90% and specificity of 67.4%, whereas LAA volume >9.25 ml had the highest predictive value for AF recurrence after RFA, with the sensitivity of 85.2% and specificity of 67.9%. In conclusion, the volume of left atrium, volume and morphology of left atrial appendage have all significantly increased while the ejection fraction and volume strain of left atrium and left atrial appendage have both significantly decreased in recurrence than in non-recurrence after radiofrequency ablation. The ejection fraction and volume of left atrial appendage are significant independent predictors of atrial fibrillation recurrence after radiofrequency ablation.

Difference in left atrial appendage remodeling between diabetic and nondiabetic patients with atrial fibrillation

Background

Diabetes mellitus (DM) is a common and increasingly prevalent condition in patients with atrial fibrillation (AFib). The left atrium appendage (LAA), a small outpouch from the LA, is the most common location for thrombus formation in patients with AFib.

Hypothesis

In this study, we examined LAA remodeling differences between diabetic and nondiabetic patients with AFib.

Methods

This retrospective study analyzed data from 242 subjects subdivided into two subgroups of 122 with DM (diabetic group) and 120 without DM (nondiabetic group). The study group underwent real‐time 3‐dimensional transesophageal echocardiography (RT3DTEE) for AFib ablation, cardioversion, or LAA device closure. The LAA dimensions were measured using the “Yosefy rotational 3DTEE method.”

Results

The RT3DTEE analysis revealed that diabetic patients display larger LAA diameters, D1‐lengh (2.09 ± 0.50 vs 1.88 ± 0.54 cm, P = .003), D2‐width (1.70 ± 0.48 vs 1.55 ± 0.55 cm, P = .024), D3‐depth (2.21 ± 0.75 vs 1.99 ± 0.65 cm, P = .017), larger orifice areas (2.8 ± 1.35 and 2.3 ± 1.49 cm², P = .004), and diminished orifice flow velocity (37.3 ± 17.6 and 43.7 ± 19.5 cm/sec, P = .008).

Conclusions

Adverse LAA remodeling in DM patients with AFib is characterized by significantly LAA orifice enlargement and reduced orifice flow velocity. Analysis of LAA geometry and hemodynamics may have clinical implications in thrombotic risk assessment and treatment of DM patients with AFib.

A lower left atrial appendage peak emptying velocity in the acute phase of cryptogenic stroke predicts atrial fibrillation occurrence during follow-up

BACKGROUND

Silent atrial fibrillation is a frequent etiology of cryptogenic stroke. Spontaneous conversion of atrial fibrillation to sinus rhythm results in atrial stunning.

OBJECTIVE

To evaluate if the presence of a lower left atrial appendage peak emptying velocity (LAAV) after a cryptogenic stroke is associated with the occurrence of atrial fibrillation (AF).

METHODS

We retrospectively selected consecutive patients with an acute ischemic stroke that had a transoesophageal echocardiogram (TEE) performed in the first 30 days of the acute event. Documented AF or potential cardioembolic sources in the TEE were considered exclusion criteria. We assessed the LAAV. During follow-up, we evaluated the occurrence of new-onset AF and the combined endpoint of death or new ischemic stroke.

RESULTS

We studied 73 consecutive patients, during a mean follow-up period of 54.9 ± 19.3 months. Seven developed AF, and 13 had the combined endpoint. LAAV was independently associated with AF occurrence (HR: 0.93, 95% CI: 0.88-0.99; P = .016). Patients with a LAAV ≤ 46.5 cm/s (AUC: 0.766, 95% CI: 0.579-0.954; P = .021) had a lower survival rate free from AF occurrence (Log-rank, P < .001) and free from the combined endpoint of death or ischemic stroke (Log-rank, P = .010).

CONCLUSION

A lower LAAV was associated with AF occurrence and the combined endpoint of death or ischemic stroke after an initial episode of cryptogenic stroke. Patients with this finding could eventually benefit from long-term cardiac rhythm monitoring.

Predictors of successful complex catheter ablation for persistent atrial fibrillation despite failure of targeted procedural arrhythmia termination

INTRODUCTION

Procedural atrial fibrillation (AF) termination is considered as a predictor of long-term success after catheter ablation for persistent AF (persAF). However, some patients remain free of arrhythmia recurrences despite failure to achieve AF termination. The objective of this study was to assess long-term outcome and prognostic factors in patients undergoing complex ablation without procedural AF termination.

METHODS AND RESULTS

This study comprised 419 patients (63.8 ± 10.2 years, 63.4% male) undergoing complex ablation for persAF. Patients without procedural AF termination (n = 137, 64.2 ± 9.7 years, 63.5% male) were categorized into patients who remained in sinus rhythm (SR) in long-term outcome (SR-group) and patients with recurrence of AF or atrial tachycardia (AT) (AR-group). During a follow-up (FU) of 19.6 ± 14.6 months, the SR-group consisted of 65 (47.5%) and the AR-group of 69 (50.4%) patients. Three patients (2.2%) were lost to FU. Left atrial appendage (LAA) flow velocity and left atrium volume index (LAVI) could be identified as predictors for long-term success. LAA flow velocity and baseline AF cycle length (AFCL) were significantly associated with the type of arrhythmia recurrence (AF vs AT), ie, higher values of both are predictive for AT rather than AF recurrences. Patients with a LAVI < 34.4 mL/m² and significant AFCL increase during the ablation procedure had rather AT than AF recurrences.

CONCLUSION

Patients with an arrhythmia-free outcome despite failure of procedural AF termination during complex ablation for persAF are characterized by specific morphological and functional properties that are easy to obtain.

Effect of pulmonary vein isolation on left atrial appendage flow in paroxysmal atrial fibrillation

BACKGROUND

Left atrial appendage (LAA) functional modification in the context of pulmonary vein isolation has been a focus point of research and LAA emptying flow velocity (LAAEFV) is considered to reflect LAA contractility, stunning, and fibrosis.

OBJECTIVE

In the present study, we sought to prospectively evaluate short-term LAAEFV changes after radiofrequency (RF) or cryoballoon ablation in paroxysmal AF.

METHODS

This was a prospective substudy of the Effect of Cryoballoon and RF Ablation on Left Atrial Function (CryoLAEF) study (ClinicalTrials.gov Identifier: NCT02611869). Thirty patients, randomly assigned to RF or cryoablation, were prospectively followed. Transesophageal echocardiograms were performed at baseline and at 3 months postablation to measure LAAEFV.

RESULTS

All measurements were performed in sinus rhythm. Overall, LAAEFV was 44.2 [38.5-62.8] cm/s at baseline and was increased to 70.8 [64.8-77.6] cm/s at 3 months' postablation (P < 0.001). Baseline LAAEFV was 52.5 [37.7-68.0] cm/s in the RF group and 42.8 [38.7-52.9] cm/s in the CryoBalloon group (P  =  0.653). At 3 months, the corresponding values were 68.5 [61.9-76.6] cm/s and 73.9 [69.2-79.9] cm/s, respectively (P  =  0.081 for the difference between the two groups at 3 months). The median change in LAAEFV was 11.0 [4.7-26.2] cm/s in the RF group versus 29.6 [15.8-37.0] cm/s in the CryoBalloon group (P  =  0.033).

CONCLUSION

LAA function is improved after catheter ablation with RF or balloon cryoablation in patients with paroxysmal AF, evaluated while in sinus rhythm both at baseline and on follow-up.

Transesophageal echocardiography measures left atrial appendage volume and function and predicts recurrence of paroxysmal atrial fibrillation after radiofrequency catheter ablation

AIMS

Paroxysmal atrial fibrillation (PAF) commonly recurs after radiofrequency catheter ablation (RFCA). This study aimed to assess left atrial appendage (LAA) volume and function by transesophageal echocardiography (TEE) and to explore its value in predicting PAF recurrence after RFCA.

METHODS

Eighty patients with PAF were recruited. The left atrial (LA) and LAA volume and function were measured by transthoracic echocardiography (TTE) and TEE before ablation. Patients were followed up for 12 months after RFCA, and recurrence was recorded. Odds ratios of candidate risk indicators were determined by logistic regression analysis. Prediction model was constructed using logistic regression with backward selection. Receiver operating characteristic (ROC) curve with area under curve (AUC) was performed to evaluate the prediction efficiency.

RESULTS

Twenty-four (30%) PAF patients had recurrence (R group), and 56 (70%) patients had no recurrence (NR group). Compared to NR group, LA dimension (LAD), LA volume index (LAVI), LAA maximum volume (LAAVmax), and LAA minimum volume (LAAVmin) were significantly higher in R group, while LAA peak emptying flow velocity (LAAeV), LAA peak filling flow velocity (LAAfV), and LAA ejection fraction (LAAEF) significantly declined in R group. According to multivariate analysis and backward selection, LAVI, LAAEF, and LAAeV were significant risk factors for PAF recurrence. The LAVI + LAAEF + LAAeV joint model could effectively predict PAF recurrence with AUC of 0.893 (95% confidence interval = 0.816, 0.970), sensitivity of 0.75, and specificity of 0.929.

CONCLUSIONS

This study demonstrated that LAVI, LAAEF, and LAAeV were significant predictors of PAF recurrence after RFCA.

Left Atrial Appendage characteristics in patients with Persistent Atrial Fibrillation undergoing catheter ablation (LAAPAF Study)

Background

Despite technological and scientific efforts, the recurrence rate of persistent atrial fibrillation (AF) remains high. Several studies have shown that in addition to pulmonary vein (PV) isolation other non-PV triggers, particularly left atrial appendage may be the source of initiation and maintenance of AF. There are few studies showing the role of left atrial appendage (LAA) isolation in order to obtain higher success rate in persistent AF patients.

Objective

We analyzed the LAA volume, volume index and shape relative to the LA in patients with persistent AF undergoing AF ablation.

Methods

Fifty-nine consecutive patients with persistent AF who underwent catheter ablation were enrolled. Computerized tomography (CT) was performed in order to assess left atrial and PV anatomy including the LAA. Digital subtraction software (GE Advantage Workstation 4.3) was used to separate the LAA from the LA and calculate: LA volume (LAV), LA volume index (LAV/body surface area), LAA volume (LAAV), LAA volume index (LAA volume/LA volume), and LAA morphology [chicken wing (CW) or non-chicken wing (NCW)].

Results

The mean age was 64.6 ± 9.8 years, 44 % male, and LA diameter 47.6 ± 7.8 mm. Median follow-up (FU) was 13 months. All patients had antral isolation of PVs and ablation of complex fractionation ± linear ablation (roof line/superior coronary sinus/mitral line). Among 59 patients with persistent AF, 26 (44 %) patients were diagnosed with AF recurrences. Mean LAV was 145.0 ± 45.9 ml, LAVI 68.9 ± 20.0 ml/m², LAAV 10.3 ± 4.0 ml, and LAAVI 7.3 ± 2.7 ml/m². LAA shape was non-chicken wing (NCW) in the majority of patients (51 %). LAA parameters were not significantly different between patients with and without AF recurrence (LAAV 11.0 ± 4.3 ml vs. 9.7 ± 3.8 ml, p=0.26; LAAVI 7.5 ± 3.0 ml/m² vs. 7.2 ± 2.5 ml/m², p=0.71; LAA shape of NCW 50 % vs 52 %, p=0.75, respectively). LAV was significantly correlated with the LAAV (r: o.47, p=0.009). The incidence of NCW LAA was significantly higher in patients with previous stroke/TIA (80 % vs. 20 %, p=0.04).

Conclusion

The LAA anatomical characteristics (volume/volume index and the shape) were comparable in patients with/out AF recurrence post PVI. It remains to be determined if additional LAA isolation will impact outcomes in patients with persistent AF.

Study on the Effect of Irbesartan on Atrial Fibrillation Recurrence in Kumamoto: Atrial Fibrillation Suppression Trial (SILK study)

BACKGROUND

Experimental studies suggest that angiotensin II-receptor blockers can influence atrial remodeling and may prevent atrial fibrillation (AF). Therefore, we hypothesized that irbesartan may prevent the recurrence of AF following either catheter ablation or electrical cardioversion of AF.

METHODS

Study on the Effect of Irbesartan on Atrial Fibrillation Recurrence in Kumamoto (SILK study) is a prospective, multicenter, randomized, and open-label comparative evaluation of the effects of irbesartan and amlodipine on AF recurrence in hypertensive patients with AF who are scheduled to undergo catheter ablation or electrical cardioversion of AF. The primary end point was either AF or atrial tachycardia (AT) recurrence. AF/AT recurrence was evaluated for 6 months using 24-h Holter electrocardiogram and portable electrocardiogram. The secondary endpoints included the change in blood pressure, the interval from the procedure to the first AF/AT recurrence, cardiovascular events, left atrial diameter (LAD), left ventricular ejection fraction (LVEF), and changes in the biomarkers [brain natriuretic polypeptide (BNP), high-sensitivity C-reactive protein (hs-CRP), urinary albumin/creatinine].

RESULTS

The study enrolled 98 patients (irbesartan; n=47, amlodipine; n=51). The recurrence of AF/AT was observed in 8 patients (17.0%) in the irbesartan group and in 10 patients (19.6%) in the amlodipine group. There was no significant difference in the AF/AT recurrence between the irbesartan and amlodipine groups. Blood pressure decreased similarly in both groups. There were no significant differences between the two groups as regards to the interval from the procedure to the first AF/AT recurrence, occurrence of cardiovascular events, changes in LAD and LVEF. BNP and urinary albumin/creatinine significantly decreased similarly in both groups, but no significant difference was found in hs-CRP between the two groups.

CONCLUSIONS

In hypertensive patients with AF, treatment with irbesartan did not have any advantage over amlodipine in the reduction of AF/AT recurrence after catheter ablation or electrical cardioversion.

Left atrial appendage volume as a new predictor of atrial fibrillation recurrence after catheter ablation

PURPOSE

Recurrence of atrial fibrillation (AF) after catheter ablation is common, being clinically relevant to identify predictors of recurrence. The left atrial appendage (LAA) role as an AF trigger is scarcely explored. Our aim was to identify if LAA volume is an independent predictor of AF recurrence after catheter ablation.

METHODS

We analysed 52 patients (aged 54 ± 10 years, 58% male) with paroxysmal and persistent AF who underwent a first AF catheter ablation and had performed contrast-enhanced cardiac computed tomography (CT) prior to the procedure.

RESULTS

The mean left atrial and LAA volumes measured by cardiac CT were 98.9 ± 31.8 and 9.3 ± 3.5 mL, respectively. All patients received successful pulmonary vein isolation and were followed up for 24 months. AF recurrence occurred in 17 patients (33%). LAA volume was significantly greater in patients with AF recurrence than in those without recurrence (11.3 ± 2.9 vs. 8.2 ± 3.4 mL; p = 0.002). Multivariable analysis using Cox regression revealed that LAA volume (hazard ratio 1.32; 95% confidence interval 1.12-1.55; p = 0.001) and persistent AF (hazard ratio 4.22; 95% confidence interval 1.48-12.07; p = 0.007) were independent predictors for AF recurrence. An LAA volume greater than 8.825 mL predicted AF recurrence with 94% sensitivity and 66% specificity. The Kaplan-Meier analysis showed a lower rate free from AF recurrence in the group with an LAA volume >8.825 mL (p < 0.001).

CONCLUSIONS

Larger LAA volume was associated with AF recurrence after catheter ablation in patients with paroxysmal and persistent AF.

The Right to Left Atrial Volume Ratio Predicts Outcomes after Circumferential Pulmonary Vein Isolation of Longstanding Persistent Atrial Fibrillation

BACKGROUND

We aimed to identify the predictors of clinical outcomes after circumferential pulmonary vein isolation (CPVI) without any substrate modification for longstanding persistent atrial fibrillation (LSP-AF).

METHODS

This study retrospectively analyzed 70 consecutive LSP-AF patients who underwent an initial CPVI and were followed-up for more than 1 year. The right and left atrial volumes indexed to the body surface areas (right atrial volume index [RAVI] and left atrial volume index [LAVI]) were determined by preacquired contrast-enhanced computed tomography (CT). The %RAVI/LAVI was obtained as 100 × RAVI/LAVI.

RESULTS

During a median follow-up period of 15 months (interquartile range, 13-19 months), 21 patients (30%) had arrhythmia recurrences after the CPVI. Antiarrhythmic drugs were continued in 34 patients (48%). In the Cox proportional hazard model, the %RAVI/LAVI was a significant positive predictor of arrhythmia recurrences (hazard ratio, 1.048; P = 0.039). A receiver-operating characteristic analysis demonstrated that at an optimal cutoff of 100.1 for the %RAVI/LAVI, the sensitivity and specificity for predicting arrhythmia recurrences were 85.7% and 71.4%, respectively. The Kaplan-Meier analysis showed that arrhythmia recurrences were less frequent in patients with a %RAVI/LAVI of <100.1 than in those with a %RAVI/LAVI of ≥100.1 (P < 0.0001), and the arrhythmia-free survival rate at 12 months was 89.7% and 45.2%, respectively.

CONCLUSIONS

The ratio of the RAVI to LAVI on CT may be a useful predictor of clinical outcomes after CPVI of LSP-AF. LSP-AF patients with a less predominant right atrial enlargement relative to the left atrial enlargement may be good candidates for successful treatment with CPVI alone as the ablation strategy for LSP-AF.

Relationship between vitamin D level and left atrial fibrosis in patients with lone paroxysmal atrial fibrillation undergoing cryoballoon-based catheter ablation

BACKGROUND

Left atrial (LA) fibrosis is known as the hallmark for arrhythmogenic substrate in atrial fibrillation (AF). Quantification of LA fibrosis by using delayed-enhanced magnetic resonance imaging (DE-MRI) in AF patients is a pioneering noninvasive technique. Vitamin D (vitD) negatively regulates the renin-angiotensin system, binds to vitD receptors on cardiac myocytes, and has antioxidant properties that may ameliorate the inflammation and proarrhythmic substrate formation. However, its role in LA fibrosis is unclear. We aimed to investigate the association of serum 25(OH)D level with the extent of LA fibrosis by using DE-MRI and also predictors for AF recurrence after cryoablation was assessed in patients with paroxysmal AF.

METHODS

A total of 48 patients with lone paroxysmal AF (41.7% female; age: 48.5±8.4 years) who underwent DE-MRI at 1.5T and initial cryoballoon-based catheter ablation along with 48 healthy control subjects were enrolled. Fibrosis degree was categorized according to Utah class defined in the DECAAF study.

RESULTS

Serum 25(OH)D levels were significantly lower in AF group compared to control group (25.8±7.6ng/ml vs. 31.0±9.5ng/ml, p=0.004). Serum 25(OH)D levels were associated with moderate-severe LA fibrosis independent of other measures (OR: 0.72, 95% CI: 0.54-0.97, p=0.028). At a mean 16.5±2.6 months follow-up, late recurrence was observed in 10 (20.8%) patients. In multivariable Cox regression analysis, LA volume index (HR: 1.42, 95% CI: 1.01-2.01, p=0.045) and the extent of LA fibrosis (HR: 1.14, 95% CI: 1.01-1.28, p=0.034) were found as independently associated with late AF recurrence during follow-up.

CONCLUSION

Lower levels of serum 25(OH)D are significantly associated with more extensive LA fibrosis in patients with lone paroxysmal AF and may be implicated in the pathophysiology of AF recurrence after cryoablation. Further large-scale studies are needed to elucidate the exact role of vitD deficiency and replacement on LA fibrosis.

A cost-utility analysis for catheter ablation of atrial fibrillation in combination with warfarin and dabigatran based on the CHADS2 score in Japan

BACKGROUND

We aimed to clarify the cost-effectiveness of an expensive combination therapy for atrial fibrillation (AF) using both catheter ablation and dabigatran compared with warfarin at each CHADS₂ score for patients in Japan.

METHODS

A Markov model was constructed to analyze costs and quality-adjusted life years associated with AF therapeutic options with a time horizon of 10 years. The target population was 60-year-old patients with paroxysmal AF. The indication for anticoagulation was determined according to the Japanese guideline. Anticoagulation-related data were derived from the RE-LY study and the AF recurrence rate was set at 2.7% per month during the first 12 months and at 0.40% per month afterwards. Stroke risk was determined according to AF recurrence, anticoagulation, and CHADS₂ score. The risks for stroke recurrence and stroke death were also considered. Costs were calculated from the healthcare payer's perspective, and only direct medical costs were included.

RESULTS

Warfarin was the most preferred option for patients with a CHADS₂ score of 0 from a health economics aspect. Ablation under warfarin was preferred for a CHADS₂ score of 1-3, while ablation under dabigatran was preferred for a CHADS₂ score ≥4. The quality of life score for AF had the largest impact on the incremental cost-effectiveness ratios in the analysis between the anticoagulation arm and the anticoagulation+ablation arm for a CHADS₂ score of 2. Within the range of the Japanese willingness-to-pay threshold (¥5,000,000), the ablation+warfarin arm became the best option with its probability of 81.7% for a CHADS₂ score of 2; the dabigatran+ablation arm was the most preferred option with its probability of 56.1% for a CHADS₂ score of 4.

CONCLUSIONS

Ablation under dabigatran therapy is an expensive therapeutic option, but it might benefit patients with a low quality of life and a high CHADS₂ score.