Right atrial diameter and outcome of catheter ablation of atrial fibrillation

The soluble ST2 level predicts risk of atrial fibrillation recurrences in long-term period after radiofrequency ablation

BACKGROUND AND OBJECTIVES

The hypothesis of the study was the assumption that the serum levels of soluble ST2 (sST2) and growth differentiation factor (GDF-15) can be predictors of atrial fibrillation (AF) recurrence in long-term period after primary radiofrequency catheter ablation (RFA).

METHODS

Of the 165 patients included in the prospective follow-up, the final analysis included 131 patients whose follow-up duration reached 18 months after the end of the blanking period (3 months after RFA). The median age of patients was 59.0 (50.0; 64.0) years, and 80 (61%) were men. Paroxysmal AF was present in 103 (79%) and persistent AF in 28 (21%) patients. All patients underwent transthoracic and transesophageal echocardiography, and electroanatomic mapping was used to assess the area of low-voltage zones (LVZ). sST2 and GDF-15 levels were determined by ELISA using GDF-15/MIC-1 analytical kits (BioVender, Czech Republic) and Presage ST2 (Critical Diagnostics, USA) before RFA. After RFA, patients had regular follow-up visits at 3-6-9-12-18 months with 12-lead ECG or Holter ECG monitoring and with clinical evaluation. The primary endpoint was the occurrence of the first symptomatic AF recurrence (AFr) lasting > 30 s, recorded on an ECG or during daily ECG monitoring, after a blanking period.

RESULTS

At the 18-month follow-up, 47 patients (35.9%) had AFr. The groups with and without AFr didn`t differ in the LVZ area. The medians of NT-proBNP, GDF-15 and sST2 also didn`t differ significantly between the groups, but in patients with AFr, the proportion of those with sST2 ≥ 36 ng/ml (the border of the lower and middle terziles) was higher (p = 0.03). According to the one-factor Cox regression analysis, AFr were associated with four factors: AF history ≥ 1 year, early AFr (during the blanking period), left atrial appendage flow velocity (LAAFV) < 54 cm/sec and sST2 ≥ 36 ng/ml. In the multivariate Cox analysis two independent predictors of AFr were obtained: sST2 ≥ 36 ng/ml (HR = 3.8; 95% CI 1.5-9.8, p = 0.006) and LAAFV < 54 сm/sec (HR = 1.96; 95% CI 1.01-3.82, p = 0.048).

CONCLUSIONS

Serum sST2 level with a cut-off value of 36 ng/ml or more can be used as a predictor of AF recurrence in the long-term period after primary RFA.

The role of the right atrial appendage and right atrium in post-radiofrequency ablation recurrence in different types of atrial fibrillation

AIM

To quantitatively evaluate the relationship between the anatomical parameters of the right atrium and the recurrence of atrial fibrillation (AF) after radiofrequency ablation, considering different types of AF, utilizing 256-slice spiral computed tomography (CT).

MATERIALS AND METHODS

A total of 297 patients with AF who underwent initial radiofrequency ablation were enrolled, divided into the paroxysmal atrial fibrillation (PaAF) group (n=230) and the persistent atrial fibrillation (PeAF) group (n=67). Subsequently, patients in each group were further stratified into recurrent and non-recurrent subgroups. In addition, 100 healthy outpatients were selected as the normal group. All patients underwent preoperative cardiac CT (CCT) examination. The volumes of the right atrium (RA), right atrial appendage (RAA), and left atrial (LA), RAA height, the length, short diameter, perimeter, and area of the RAA base, anteroposterior diameter of the RA, tricuspid annulus diameter, crista terminalis, and inferior vena cavotricuspid isthmus (CTI) on CCT images were measured.

RESULTS

In both the PaAF group and the PeAF group, except for the crista terminalis thickness, the other measured parameters were greater than those in the normal group, and recurrent patients exhibited larger RAA base, crista terminalis and LA volume. Recurrent patients with PeAF presented larger RAVI, while recurrent patients with PaAF did not. The short diameter of the RAA base was an independent predictor of recurrence in patients with PaAF (p=0.001), while the height of the RAA, thickness of the crista terminalis, and hypertension were independent predictors of recurrence in PeAF (p<0.05). The ROC curve was used to analysis the predictive model in PaAF and PeAF group, the corresponding sensitivity and specificity were 0.604 and 0.864 in PaAF group, respectively (AUC = 0.840, P=0.001), in PeAF group, the corresponding sensitivity and specificity were 0.967 and 0.892, respectively (AUC = 0.959, P=0.001). The short diameter of RAA base > 22.15 mm had the highest predictive value for recurrence in PaAF patients, with a sensitivity of 0.887, and a specificity of 0.520 (AUC: 0.743, p=0.001). The RAA height > 28.95 mm has the highest predictive value for recurrence in PeAF, with a sensitivity of 0.633, and a specificity of 0.865 (AUC: 0.816, p=0.001).

CONCLUSION

Recurrent patients both in the PaAF and PeAF groups demonstrated larger RAA base and RA structural parameters. Compared to patients with PaAF, recurrent patients with PeAF presented larger RA volume.

Adjunctive Right Atrial Ablation for Persistent Atrial Fibrillation With Right Atrial Enlargement: A Pilot Study

BACKGROUND

Persistent atrial fibrillation (PerAF) is often associated with right atrial (RA) enlargement. We investigated the efficacy of RA intervention in patients with PerAF and RA enlargement.

METHODS

Patients with PerAF and RA enlargement were randomised (1:1) to receive adjunctive RA ablation (left atrial [LA] + RA group; n = 60) or to receive LA ablation alone (LA-only group; n = 60). In the LA + RA group, RA ablation was performed if LA ablation failed to terminate AF. The primary end point was freedom from AF/atrial tachycardia (AT) recurrence at 12 months after a single ablation procedure without antiarrhythmic drug therapy.

RESULTS

In the LA + RA group, 40 patients (67%) required RA ablation. The LA + RA group had a higher rate of acute AF termination than the LA-only group (63.3% vs 36.7%; P = 0.003). At the end of 12-month follow-up, 42 patients (70%) in the LA + RA group were free of AF/AT recurrence, compared with 31 (51.7%) in the LA-only group (log rank P = 0.034; hazard ratio 0.549, 95% confidence interval 0.310-0.974). The rate of freedom from AF recurrence was also higher in the LA + RA group than in the LA-only group (81.7% vs 63.3%; log rank P = 0.019). The 2 groups had similar rates of adverse events (5% vs 3.3%; P = 0.648).

CONCLUSIONS

Adjunctive RA ablation increased the success rate of a single ablation in patients with PerAF and RA enlargement.

CHINESE CLINICAL TRIAL REGISTRATION

ChiCTR220056844.

An effective prediction model based on XGBoost for the 12-month recurrence of AF patients after RFA

BACKGROUND

Atrial fibrillation (AF) is a common heart rhythm disorder that can lead to complications such as stroke and heart failure. Radiofrequency ablation (RFA) is a procedure used to treat AF, but it is not always successful in maintaining a normal heart rhythm. This study aimed to construct a clinical prediction model based on extreme gradient boosting (XGBoost) for AF recurrence 12 months after ablation.

METHODS

The 27-dimensional data of 359 patients with AF undergoing RFA in the First Affiliated Hospital of Soochow University from October 2018 to November 2021 were retrospectively analysed. We adopted the logistic regression, support vector machine (SVM), random forest (RF) and XGBoost methods to conduct the experiment. To evaluate the performance of the prediction, we used the area under the receiver operating characteristic curve (AUC), the area under the precision-recall curve (AP), and calibration curves of both the training and testing sets. Finally, Shapley additive explanations (SHAP) were utilized to explain the significance of the variables.

RESULTS

Of the 27-dimensional variables, ejection fraction (EF) of the left atrial appendage (LAA), N-terminal probrain natriuretic peptide (NT-proBNP), global peak longitudinal strain of the LAA (LAAGPLS), left atrial diameter (LAD), diabetes mellitus (DM) history, and female sex had a significant role in the predictive model. The experimental results demonstrated that XGBoost exhibited the best performance among these methods, and the accuracy, specificity, sensitivity, precision and F1 score (a measure of test accuracy) of XGBoost were 86.1%, 89.7%, 71.4%, 62.5% and 0.67, respectively. In addition, SHAP analysis also proved that the 6 parameters were decisive for the effect of the XGBoost-based prediction model.

CONCLUSIONS

We proposed an effective model based on XGBoost that can be used to predict the recurrence of AF patients after RFA. This prediction result can guide treatment decisions and help to optimize the management of AF.

Impact of catheter ablation on functional tricuspid regurgitation in patients with atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) plays the main role in atrial functional tricuspid regurgitation (TR). However, the effectiveness of catheter ablation (CA) for atrial functional TR together with the mechanisms of improvement of atrial functional TR have not been fully evaluated.

METHODS

We retrospectively investigated consecutive 2685 patients with AF who received CA from February 2004 to December 2019 in Kyoto University Hospital, Kyoto, Japan. The current study population consisted of 2331 patients with available transthoracic echocardiographic (TTE) data before CA (2110 patients without significant TR and 221 patients with significant TR). Among the 221 patients with significant TR, there were 64 patients with functional TR and follow-up TTE at 6-18 months after CA for AF, in whom we compared echocardiographic parameters from baseline to follow-up.

RESULTS

Patients with significant TR were older, and more often women, and had more persistent AF than those without significant TR. Among the 64 patients with functional TR, TR severity and TR jet area significantly improved at follow-up (TR jet area: 5.8 [4.0-7.6] cm2 to 2.1 [1.1-3.1] cm2, P < 0.001). Moreover, mitral regurgitation jet area, left atrial area, mitral valve diameter, right ventricular end-diastolic area, right atrial area, and tricuspid valve diameter decreased at follow-up.

CONCLUSIONS

TR severity and jet area improved after CA in patients with AF and significant TR. The improvement of TR might be associated with reverse remodeling of the right heart.

Biatrial volume ratio predicts low voltage areas in atrial fibrillation

BACKGROUND

Left atrial volume (LAV) and low voltage areas (LVAs) are acknowledged markers for worse rhythm outcome after ablation of atrial fibrillation (AF). Some studies reported the importance of increased right atrial volume (RAV) as a predictor for arrhythmia recurrences in AF patients.

OBJECTIVE

To investigate association between the LAV/RAV ratio and LVAs presence.

METHODS

Patients undergoing first AF ablation were included. LVAs were assessed peri-procedurally using high-density 3D maps and defined as <0.5 mV. All patients underwent pre-procedural cardiovascular magnetic resonance imaging. LAV (biplane) and RAV (monoplane 4-chamber) were assessed prior to ablation, and the LAV/RAV ratio was calculated.

RESULTS

The study population included 189 patients (age mean 63 ± 10 years, 33% women, 57% persistent AF, 22% LVAs). There were 149 (79%) patients with LAV > RAV. In univariable analysis LAV > RAV was associated with LVAs (OR 6.803, 95%CI 1.395-26.514, p = .016). The association remained robust in multivariable model after adjustment for persistent AF, CHA₂ DS₂ -VASc score, and heart rate (OR 5.981, 95%CI 1.256-28.484, p = .025). Using receiver operator curve analysis, LAV > RAV (AUC 0.668, 95%CI 0.585-0.751, p = .001) was significant predictor for LVAs. In multivariable analysis, after adjustment for age, persistent AF, and renal function, RAV≥LAV was threefold higher in males (OR 3.040, 95%CI 1.050-8.802, p = .04).

CONCLUSIONS

LAV > RAV is useful for the prediction of electro-anatomical substrate in AF. LAV > RAV was associated with LVAs presence, while male sex remained associated with RAV≥LAV and less LVAs.

Impact of right atrial structural remodeling on recurrence after ablation for atrial fibrillation

BACKGROUND

Recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) is associated with left atrial (LA) remodeling; however, its association with right atrial (RA) remodeling remains unclear.

OBJECTIVE

This study aimed to identify whether RA structural remodeling could predict recurrence of AF after PVI.

METHODS

This study prospectively analyzed 245 patients with AF who had undergone PVI. RA and LA volumes were determined by contrast-enhanced computed tomography. Atrial structural remodeling was defined as an atrial volume of ≥110 mL according to previous reports and receiver operating characteristic curve analysis.

RESULTS

After excluding 32 patients, 213 patients were analyzed. During a follow-up period of 12 months, 41 patients (19%) demonstrated atrial arrhythmia recurrence after PVI. With the Cox proportional-hazards model, RA structural remodeling was the only predictor of arrhythmia recurrence (hazard ratio, 1.012; 95% confidence interval 1.003-1.021; P = .009). Kaplan-Meier analysis showed that arrhythmia recurrence was more frequent in the RA structural remodeling group compared with the group without RA remodeling (log-rank, P < .001), and the arrhythmia-free survival rates in these groups at 12 months were 68.0% and 91.4%, respectively. Additionally, there was a significant difference in recurrence-free survival after RA structural remodeling in each type of AF (log-rank, P < .001).

CONCLUSIONS

RA structural remodeling is a useful predictor of clinical outcome after PVI regardless of the type of AF. Our results suggest that patients without RA structural remodeling may be good candidates for successful ablation with PVI.

Higher Incidence of Atrial Fibrillation in Left Ventricular-to-Right Atrial Shunt Patients

Background: The possible association between atrial fibrillation (AF) and left ventricular-to-right atrial shunt (LVRAS) has never been reported yet. The present study investigated the incidence of AF in LVRAS. Methods: This was a retrospective study of consecutive patients undergoing echocardiography at a single tertiary center. Clinical data, laboratory results and echocardiography parameters such as right atrial area (RAA), right ventricular end diastolic diameter (RVDD) and left atrial diameter (LAD) were compared between LVRAS group and non-LVRAS patients, and between AF and non-AF patients. Propensity score matching was performed to decrease the effect of confounders. Logistic regression analysis and mediation analysis were used to estimate the relationship between LVRAS and AF. Results: A total of 3,436 patients were included, and the incidence of LVRAS was 1.16% (n = 40). The LVRAS group had significantly larger RAA, RVDD and LAD compared with non-LVRAS group. Those who suffered from AF showed larger RAA, RVDD and LAD compared with those who maintained sinus rhythm. Multivariable logistic regression showed that gender (OR: 0.608), age (OR: 1.048), LAD (OR: 1.111), mean pulmonary artery blood pressure (mPAP, OR: 1.023), TR (OR: 2.309) and LVRAS (OR: 12.217) were significant factors for AF. RAA could partially mediate the relationship between LVRAS and AF according to the result of mediation analysis. Conclusions: Our study suggested that LVRAS, TR, LAD, mPAP, age and male were risk factors for AF. RA enlargement might underlie mechanism in the higher incidence of AF in LVRAS patients. These findings should be confirmed in larger prospective studies.

Simultaneous hybrid maze procedure for long-standing persistent atrial fibrillation with dilated atrium

Background

The efficacy of catheter-based or thoracoscopic ablation for treating long-standing persistent atrial fibrillation (AF) with a dilated atrium remains suboptimal. This study aimed to assess the feasibility and initial results of simultaneous hybrid ablation with a new biatrial lesion set in these patients.

Methods

Twenty-seven consecutive patients with long-standing persistent AF and dilated atrium underwent simultaneous hybrid ablation with a new biatrial lesion set consistent with the principle of the Cox maze procedure at our institution. Patients were followed up at 3, 6, and 12 months after the procedure and annually thereafter.

Results

After thoracoscopic epicardial ablation, endocardial mapping confirmed complete bilateral pulmonary vein isolation in 25 patients (96.2%). All patients were followed for a mean of 18.7 ± 8.9 months. Freedom from atrial tachyarrhythmia at 1 year after the single hybrid procedure was 64% with antiarrhythmic drugs and 60% without antiarrhythmic drugs. Freedom from atrial tachyarrhythmia at latest follow-up after the hybrid procedure and redo catheter ablation was 77.8% with antiarrhythmic drugs and 74.1% without antiarrhythmic drugs. In patients with sinus rhythm restoration, mean left atrial diameter decreased from 54.4 ± 4.3 mm to 45.2 ± 4.1 mm (P < .001), and mean right atrial diameter decreased from 59.4 ± 3.9 mm to 54.9 ± 4.4 mm (P < .001). Postoperative pleural effusion was observed in 3 patients (11.1%), and no adverse events occurred during follow-up.

Conclusions

In patients with long-standing persistent AF and a dilated atrium, simultaneous hybrid ablation with the new biatrial lesion set, in combination with touch-up catheter ablation when necessary, can achieve promising results. More studies are needed to confirm these findings.

Cryoablation Combined with Left Atrial Appendage Closure: A Safe and Effective Procedure for Paroxysmal Atrial Fibrillation Patients

Background

Catheter ablation combined with left atrial appendage closure (LAAC) was reported as a feasible strategy for atrial fibrillation (AF) patients with high risk of stroke or contraindications of oral anticoagulants. We aimed to observe the short-term safety and efficacy of combining cryoballoon ablation (CBA) with LAAC in paroxysmal (PAF) patients. Method and Results. From Jan 2016 to Dec 2017, 304 patients diagnosed with nonvalvular, drug-refractory PAF were included, who underwent either CBA alone (n = 262) or combined procedure (n = 42). Instant pulmonary vein isolation (PVI) with CBA was achieved in all patients, while successful LAAC achieved in 41 (97.6%) of combined procedure patients. 1-year freedom of AF rate was lower in combined procedure group (84.7% vs 70.7%, p = 0.04), with unadjusted hazard ratio (HR = 1.97) and 95% confidence interval (CI) 1.03–3.77. However, the multivariate COX model revealed left atrial diameter (p = 0.002, HR = 1.10, and 95% CI 1.04, 1.17), rather than procedure type (p = 0.51, HR = 1.34, and 95% CI 0.57, 3.17), was the predictor for freedom of AF. Only 2 patients in the CBA group had stroke, contributing to the nonsignificant higher stroke incidence (p = 1.00). Transoesophageal echochardiography (TEE) achieved in 35 patients (83.3%) showed complete occlusion with no obvious residual flow (>3 mm), Device-related thrombosis, or pericardial perfusion. All-cause mortality, rehospitalization, and complication rates were similar.

Conclusion

Combining CBA with LAAC in a single procedure is a feasible strategy for PAF patients, with comparable short-term safety and efficacy to CBA alone.

Biatrial enlargement as a predictor for reablation of atrial fibrillation

Purpose: We aimed to determine whether biatrial enlargement could predict reablation of atrial fibrillation after first ablation. Methods: 519 consecutive patients with drug resistant atrial fibrillation [paroxysmal AF (PAF) 361, non-PAF 158] who underwent catheter ablation in Capital Medical University Xuanwu hospital between 2009 and 2014 were enrolled. Biatrial enlargement (BAE) was diagnosed according to trans-thoracic echocardiography (TTE). Ablation strategies included complete pulmonary vein isolation (PVI) in all patients and additional linear ablation across mitral isthmus, left atrium roof, left atrium bottom and tricuspid isthmus, or electrical cardioversion on the cases that AF could not be terminated by PVI. Anti-arrhythmic drugs or cardioversion were used to control the recurred atrial arrhythmia in patients with recurrence of atrial fibrillation after ablation. Reablation was advised when the drugs were resistant or that patient could not tolerate. Risk factors for reablation were analyzed. Results: After 33.11±21.45months, 170 patients recurred atrial arrhythmia, and reablation were applied in 117 patients. Multivariate Cox regression analysis demonstrated that that biatrial enlargement (BAE, HR 1.755, 95%CI 1.153-2.670, P=0.009) was an independent predictor for reablation and was associated with reablation (Log rank P=0.007). Conclusion: Biatrial enlargement is an independent risk predictor for the reablation in atrial fibrillation patients after first ablation.

Association of peak atrial longitudinal strain with atrial fibrillation recurrence in patients with chronic lung diseases following radiofrequency ablation

BACKGROUND

Strain was shown associated with atrial fibrillation (AF) recurrence after radiofrequency ablation (RFA), but data on AF patients complicated with chronic lung diseases (CLD) were rare.

AIM

This study was designed to evaluate the relationship of baseline atrial function with AF recurrence in these patients using speckle-tracking echocardiography.

METHODS

Average strain values (median: 2 days before RFA) were calculated for 87 AF patients (Mean age: 61.91 years, male: 71.26%) with CLD undergoing RFA from 2013 to 2014. Of these patients, 25 (28.74%) experienced AF recurrence during a mean follow up of 10.3 months.

RESULTS

Peak right atrial longitudinal strain (R-PALS) was associated with peak left atrial longitudinal strain (L-PALS, Standardised β = 0.45, P < 0.001) in multivariate linear regression. Multivariate Cox regression analysis showed R-PALS was associated with AF recurrence (hazard ratio, 0.86; 95% confidence interval (CI), 0.78-0.96, P = 0.005) in CLD. Patients with R-PALS ≥14.69% had higher AF free rate compared with R-PALS<14.69% using Kaplan-Meier analysis (log-rank, P < 0.001). R-PALS had similar C-index compared to L-PALS (difference: 0.03, 95%CI: -0.06-0.12, P = 0.53) and combined R-PALS and L-PALS (difference: 0.005, 95%CI: -0.04-0.05, P = 0.84) associated with AF recurrence in CLD.

CONCLUSION

R-PALS, L-PALS and combined R-PALS and L-PALS are important factors associated with AF recurrence following RFA in patients with CLD.

Echocardiographic predictors of atrial fibrillation recurrence after catheter ablation: A literature review

BACKGROUND

Catheter ablation (CA) is a well-known treatment option for patients with symptomatic drug-resistant atrial fibrillation (AF). Multiple factors have been identified to determine AF recurrence after CA, however their predictive value is rather small. Identification of novel predictors of CA outcome is therefore of primary importance to reduce health costs and improve long-term results of intervention. The recurrence of AF following CA is related to severity of left ventricular (LV) dysfunction, extent of atrial dilatation and fibrosis. The aim of this paper was to present and discuss the latest studies on the utility of echocardiographic parameters in terms of CA effectiveness in patients with paroxysmal and persistent AF.

METHODS

PubMed, Google Scholar, EBSCO databases were searched for studies reporting echocardiographic preprocedural predictors of AF recurrence after CA. LV systolic and diastolic function, as well as atrial size, strain and dyssynchrony were taken into consideration.

RESULTS

Twenty one full-text articles were analyzed, including three meta-analyses. Several echocardiographic parameters have been reported to determine a risk of AF recurrence after CA. There are conventional methods that measure left atrial size and volume, LV ejection fraction, parameters assessing LV diastolic dysfunction, and methods using more innovative technologies based on speckle tracking echocardiography to determine left atrial synchrony and strain. Each of these parameters has its own predictive value.

CONCLUSIONS

Regarding CA effectiveness, every patient has to be evaluated individually to estimate the risk of AF recurrence, optimally using a combination of several echocardiographic parameters.