Comparison of left atrial dimensions in CT and echocardiography as predictors of long-term success after catheter ablation of atrial fibrillation

ACR Appropriateness Criteria® Preprocedural Planning for Left Atrial Procedures in Atrial Fibrillation

This document summarizes the relevant literature for the selection of preprocedural imaging in three clinical scenarios in patients needing endovascular treatment or cardioversion of atrial fibrillation. These clinical scenarios include preprocedural imaging prior to radiofrequency ablation; prior to left atrial appendage occlusion; and prior to cardioversion. The appropriateness of imaging modalities as they apply to each clinical scenario is rated as usually appropriate, may be appropriate, and usually not appropriate to assist the selection of the most appropriate imaging modality in the corresponding clinical scenarios. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

The effect of ablation settings on lesion characteristics with DiamondTemp ablation system: An ex vivo experiment

Introduction

Creating large lesion in ablations using the DiamondTemp (DTA) ablation system may reduce the frequency of arrhythmia recurrence and allow the treatment of ventricular arrhythmias. Therefore, this study aimed to investigate whether power, application time, contact force (CF), and contact angle affect lesion formation in the ventricles.

Methods

Ablations were delivered to porcine myocardial preps to evaluate the lesion characteristics. Ablations were conducted with a maximum power of 50 W, target temperature of 58°C, CF of 10, 20, or 30 g, and contact angle between the catheter tip and tissue. The ablation durations were 15, 30, 60 s, 15 s × 2, or 30 s × 2.

Results

Steam pops occurred only in cases with perpendicular contact. The lesion depth was larger in all settings in the perpendicular orientation than in the parallel orientation. The temperatures were lower in all settings in the perpendicular orientation than in the parallel orientation. The lesions became larger as CF increased with perpendicular contact and duration of ≥30 s. The longer application time resulted in larger surface area, depth, and volume of the lesion. Lesion depth was greater with single application of 30 and 60 s than with 15 s × 2 and 30 s × 2, respectively.

Conclusion

It is important to perform a single prolonged application as much as possible to create deeper lesions. Parallel contact with the tissue should be maintained to take advantage of the temperature sensor's capabilities to avoid pop phenomenon.

Catheter Ablation for Atrial Fibrillation in Patients with Heart Failure: Current Evidence and Future Opportunities

Atrial fibrillation (AF) and heart failure (HF) are highly prevalent cardiac disorders worldwide, and both are associated with poor prognosis. The incidence of AF and HF has been increasing substantially in recent years, mainly due to the progressive aging of the population. These disorders often coexist, and may have a causal relationship, with one contributing to the development or progression of the other. AF is a significant risk factor for adverse outcomes in HF patients, including mortality, hospitalization, and stroke. Although the optimal treatment for AF with HF remains unclear, catheter ablation (CA) has emerged as a promising treatment option. This review provides a comprehensive overview of the current scientific evidence regarding the efficacy of CA for managing AF in HF patients. In addition, the potential benefits and risks associated with CA are also discussed. We will also explore the factors that may influence treatment outcomes and highlight the remaining gaps in knowledge in this field.

Clinical Phenotypes and Atrial Fibrillation Recurrences after Catheter Ablation: An Unsupervised Cluster Analysis

Catheter ablation (CA) is a well-established treatment of atrial fibrillation (AF). Data-driven cluster analysis is able to better distinguish prognostically-relevant phenotype clusters among patients with AF. We performed a hierarchical cluster analysis in a cohort of AF patients undergoing a first CA and evaluate associations between identified clusters and recurrences of arrhythmia following ablation. The study included 209 AF patients treated with CA. 3 clusters with distinct characteristics were identified. Recurrences at one year occurred in 27.2% in Cluster 1, 43.2% in Cluster 2 and 60.9% in Cluster 3 (p<0.0001). Cluster classification was independently associated with arrhythmia recurrences (HR 1.58, 95% CI 1.01-2.49, p=0.046) after adjustment for age, CHA₂DS₂-VASc score, left atrial volume, type of atrial fibrillation and ejection fraction. To concluded, cluster analysis identified three statistically-driven groups among AF patients treated with CA with different risks for arrhythmia recurrences.

Is it feasible to measure pulmonary vein data using volume rendering images?

BACKGROUND

Pulmonary vein (PV) data are commonly measured on multiplanar image reformation (MPR) images and volume rendering (VR) images.

PURPOSE

To compared and analyze the advantages and disadvantages of PV data based on VR images and MPR images.

MATERIAL AND METHODS

A total of 94 patients with atrial fibrillation (AF) with imaging data were included in the study. The respective image postprocessing time and the three surgical interventionists' preferences for the two images were recorded. A paired t-test or chi-square test was used to compare their difference, and P < 0.05 was considered statistically significant.

RESULTS

There was no statistically significant difference between the data values including the maximal and minimal ostial diameters of the left superior PV (LSPV), the left inferior PV (LIPV), the right superior PV (RSPV), and the right inferior PV (RIPV) obtained by VR and MPR images (P > 0.05). Yet, the mean postprocessing time of VR images (15.10 ± 3.05 min) was shorter compared to MPR images (16.54 ± 2.60 min) (t = 22.84, P < 0.05). All three surgical interventionists preferred VR images (accounted for 85.1%, 86.2%, and 84.0%, respectively), and there was no statistical difference in the degree of image preference among the three (chi-square = 0.596, P = 0.963).

CONCLUSION

PV data measurement could be performed on both VR and MRP images; however, the data on VR images were more intuitive and more accessible for interventional surgeons.

Premature atrial contraction immediately after catheter ablation was associated with late recurrence of atrial fibrillation

BACKGROUND

Although premature atrial contractions (PACs) just after catheter ablation (CA) for atrial fibrillation (AF) are common, their clinical significance is uncertain. This study aimed to evaluate whether the PAC burden after an initial CA for AF was associated with late recurrence.

METHODS

We enrolled 346 patients with AF (median age, 65 years; 30% female; 57% with paroxysmal AF) who underwent an initial radiofrequency CA and a 24-h Holter monitoring the day after the procedure. PAC was defined as supraventricular complexes occurring ≥30% earlier than expected compared with a previous RR interval, and the number of PAC/24 h during post-procedural Holter monitoring was analyzed.

RESULTS

AF recurred in 106 patients (31%) during a median follow-up of 19 months. These patients had significantly more PAC/24 h than those without (median [interquartile range], 891 [316-4351] beats vs. 409 [162-1,303] beats; p < 0.01). The number of PACs was independently associated with AF recurrence after adjustment for clinical parameters and left atrial (LA) enlargement. Receiver operating characteristic (ROC) curve analysis revealed that 1431 PAC/24 h was the optimal cut-off value for predicting AF recurrence. Adding the PAC/24 h to the prediction model with LA diameter appeared to correctly reclassify patients who were thought to be at high risk for AF recurrence into the low-risk group and vice versa.

CONCLUSIONS

The number of PACs was an independent risk factor for AF recurrence. A 24-h Holter recording the day after an initial CA is a simple and beneficial tool for the risk stratification of AF recurrence.

The Role of the Left Atrium: From Multimodality Imaging to Clinical Practice: A Review

In recent years, new interest is growing in the left atrium (LA). LA functional analysis and measurement have an essential role in cardiac function evaluation. Left atrial size and function are key elements during the noninvasive analysis of diastolic function in several heart diseases. The LA represents a “neuroendocrine organ” with high sensitivity to the nervous, endocrine, and immune systems. New insights highlight the importance of left atrial structural, contractile, and/or electrophysiological changes, introducing the concept of “atrial cardiomyopathy”, which is closely linked to underlying heart disease, arrhythmias, and conditions such as aging. The diagnostic algorithm for atrial cardiomyopathy should follow a stepwise approach, combining risk factors, clinical characteristics, and imaging. Constant advances in imaging techniques offer superb opportunities for a comprehensive evaluation of LA function, underlying specific mechanisms, and patterns of progression. In this literature review, we aim to suggest a practical, stepwise algorithm with integrative multimodality imaging and a clinical approach for LA geometry and functional analysis. This integrates diastolic flow analysis with LA remodelling by the application of traditional and new diagnostic imaging techniques in several clinical settings such as heart failure (HF), atrial fibrillation (AF), coronary artery disease (CAD), and mitral regurgitation (MR).

Prediction of Recurrent Atrial Tachyarrhythmia After Receiving Atrial Flutter Ablation in Patients With Prior Cardiac Surgery for Valvular Heart Disease

Background: Surgical scars cause an intra-atrial conduction delay and anatomical obstacles that facilitate the perpetuation of atrial flutter (AFL). This study aimed to investigate the outcome and predictor of recurrent atrial tachyarrhythmia after catheter ablation in patients with prior cardiac surgery for valvular heart disease (VHD) who presented with AFL.

Methods: Seventy-two patients with prior cardiac surgery for VHD who underwent AFL ablation were included. The patients were categorized into a typical AFL group (n = 45) and an atypical AFL group (n = 27). The endpoint was the recurrence of atrial tachyarrhythmia during follow-up. A multivariate analysis was performed to determine the predictor of recurrence.

Results: No significant difference was found in the recurrence rate of atrial tachyarrhythmia between the two groups. Patients with concomitant atrial fibrillation (AF) had a higher recurrence of typical AFL compared with those without AF (13 vs. 0%, P = 0.012). In subgroup analysis, typical AFL patients with concomitant AF had a higher incidence of recurrent atrial tachyarrhythmia than those without it (53 vs. 14%, P = 0.006). Regarding patients without AF, the typical AFL group had a lower recurrence rate of atrial tachyarrhythmia than the atypical AFL group (14 vs. 40%, P = 0.043). Multivariate analysis showed that chronic kidney disease (CKD) and left atrial diameter (LAD) were independent predictors of recurrence.

Conclusions: In our study cohort, concomitant AF was associated with recurrence of atrial tachyarrhythmia. CKD and LAD independently predicted recurrence after AFL ablation in patients who have undergone cardiac surgery for VHD.

Quality indicators for the care and outcomes of adults with atrial fibrillation

AIMS

To develop quality indicators (QIs) that may be used to evaluate the quality of care and outcomes for adults with atrial fibrillation (AF).

METHODS AND RESULTS

We followed the ESC methodology for QI development. This methodology involved (i) the identification of the domains of AF care for the diagnosis and management of AF (by a group of experts including members of the ESC Clinical Practice Guidelines Task Force for AF); (ii) the construction of candidate QIs (including a systematic review of the literature); and (iii) the selection of the final set of QIs (using a modified Delphi method). Six domains of care for the diagnosis and management of AF were identified: (i) Patient assessment (baseline and follow-up), (ii) Anticoagulation therapy, (iii) Rate control strategy, (iv) Rhythm control strategy, (v) Risk factor management, and (vi) Outcomes measures, including patient-reported outcome measures (PROMs). In total, 17 main and 17 secondary QIs, which covered all six domains of care for the diagnosis and management of AF, were selected. The outcome domain included measures on the consequences and treatment of AF, as well as PROMs.

CONCLUSION

This document defines six domains of AF care (patient assessment, anticoagulation, rate control, rhythm control, risk factor management, and outcomes), and provides 17 main and 17 secondary QIs for the diagnosis and management of AF. It is anticipated that implementation of these QIs will improve the quality of AF care.

Formula to estimate left atrial volume using antero-posterior diameter in patients with catheter ablation of atrial fibrillation

ABSTRACT

In patients undergoing atrial fibrillation (AF) ablation, an enlarged left atrium (LA) is a predictor of procedural failure as well as AF recurrence on long term. The most used method to assess LA size is echocardiography-measured diameter, but the most accurate remains computed tomography (CT).The aim of our study was to determine whether there is an association between left atrial diameters measured in echocardiography and the left atrial volume determined by CT in patients who underwent AF ablation.The study included 93 patients, of whom 60 (64.5%) were men and 64 (68.8%) had paroxysmal AF, who underwent AF catheter ablation between January 2018 and June 2019. Left atrial diameters in echocardiography were measured from the long axis parasternal view and the LA volume in CT was measured on reconstructed three-dimensional images.The LA in echocardiography had an antero-posterior (AP) diameter of 45.0 ± 6 mm (median 45; Inter Quartile Range [IQR] 41-49, range 25-73 mm), longitudinal diameter of 67.5 ± 9.4 (median 66; IQR 56-88, range 52-100 mm), and transversal diameter of 42 ± 8.9 mm (IQR 30-59, range 23-64.5 mm). The volume in CT was 123 ± 29.4 mL (median 118; IQR 103-160; range 86-194 mL). We found a significant correlation (r = 0.702; P < .05) between the AP diameter and the LA volume. The formula according to which the AP diameter of the LA can predict the volume was: LA volume = AP diam3 + 45 mL.There is a clear association between the left atrial AP diameter measured on echocardiography and the volume measured on CT. The AP diameter might be sufficient to determine the increase in the volume of the atrium and predict cardiovascular outcomes.

No impact of sub-clinical coronary artery disease identified by cardiac CT scan on the recurrence of atrial fibrillation after a single ablation procedure

BACKGROUND

Performing a cardiac CT scan before ablation provides a better understanding of the anatomical variations of the left atrium and pulmonary veins, as well as an analysis of coronary anatomy and the calcium score. The aim of the present study was to determine whether the CT characteristics of patients with unknown CAD have an impact on recurrence of AF.

METHODS

This monocentric retrospective study included patients with AF who had undergone cardiac CT prior to a single ablation.

RESULTS

Among the 229 patients included in the study, 70 (30.5%) presented AF recurrence between 3 and 12 months after a single ablation. The prevalence of CAD confirmed by CT coronary angiogram and the coronary calcium score were similar in the two groups. Patients with recurrent atrial fibrillation had a significantly higher LAVI evaluated by CT scan than patients without recurrence. The ROC curve determined an optimal LAVI threshold of 49 mL/m². In multivariate analysis, the LAVI measured by CT scan was independently associated with the risk of AF recurrence.

CONCLUSIONS

Our study confirms that CAD is not a predictor of AF recurrence after a single ablation, unlike the LAVI. Further studies are necessary to re-evaluate the long-term conclusions of this work.

Impact of Midregional N-Terminal Pro-Atrial Natriuretic Peptide and Soluble Suppression of Tumorigenicity 2 Levels on Heart Rhythm in Patients Treated With Catheter Ablation for Atrial Fibrillation: The Biorhythm Study

Background

We assessed the impact of preprocedural plasma levels of MRproANP (midregional N‐terminal pro–atrial natriuretic peptide) and sST2 (soluble suppression of tumorigenicity 2) on recurrence of atrial fibrillation (AF) at 1 year after catheter ablation of AF.

Methods and Results

This was a prospective, multicenter, observational study including patients undergoing catheter ablation of AF. MRproANP and sST2 were measured in a peripheral venous blood preprocedure, and MRproANP was assessed in the right and left atrial blood during ablation. The primary end point was recurrent AF between 3 and 12 months postablation, defined as a documented (>30 seconds) episode of AF, flutter, or atrial tachycardia. We included 106 patients from December 2017 to March 2019; 105 had complete follow‐up, and the mean age was 63 years with 74.2% males. Overall, 34 patients (32.1%) had recurrent AF. In peripheral venous blood, MRproANP was significantly higher in patients with recurrent AF (median, 192.2; [quartile 1–quartile 3, 155.9–263.9] versus 97.1 [60.9–150.7] pmol/L; P<0.0001), as was sST2 (median, 30.3 [quartile 1–quartile 3, 23.3–39.3] versus 23.4 [95% CI, 17.4–33.0] ng/mL; P=0.0033). In the atria, MRproANP was significantly higher than in peripheral blood and was higher during AF than during sinus rhythm. Receiver operating characteristic curve analysis identified a threshold of MRproANP>107.9 pmol/L to predict AF recurrence at 1 year and a threshold of >26.7 ng/mL for sST2. By multivariate analysis, MRproANP>107.9 pmol/L was the only independent predictor of recurrent AF (OR, 24.27; 95% CI, 4.23–139.18). MRproANP<107.9 pmol/L identified subjects at very low risk of recurrence (negative predictive value >95%).

Conclusions

Elevated MRproANP level independently predicts recurrent AF, whereas sST2 levels do not appear to have any prognostic value in assessing the risk of recurrence of AF up to 1 year after catheter ablation.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03351816.

Clinical outcomes following rhythm control for atrial fibrillation: is early better?

Introduction: An integral aspect of atrial fibrillation (AF) management involves better symptom control, incorporating a rate control, rhythm control, or a combination strategy. The 2020 ESC Guidelines suggest that rhythm control strategy should be recommended for symptomatic patients, to mitigate their symptoms and improve the quality of life. However, adequately powered randomized control trials and prospective 'real-world' registries are needed to fully assess the impact of early rhythm control strategies on clinical outcomes in patients with AF.Objective: In this narrative review, we discuss clinical outcomes following rhythm management approach among patients with AF, considering the effectiveness of an early intervention strategy.Expert opinion: Patients involvement and shared decision-making are crucial when deciding the optimal management strategy among patients with AF. For those with newly diagnosed symptomatic AF, an early invasive approach such as catheter ablation may have a role in preventing AF progression and subsequent pathophysiological changes.

Feasibility and Reproducibility of Left Atrium Measurements Using Different Three-Dimensional Echocardiographic Modalities

Left atrium (LA) volume is a biomarker of cardiovascular outcomes. Three-dimensional echocardiography (3DE) provides an accurate LA evaluation, but data regarding the optimal 3DE method is scarce. We assessed the feasibility and reproducibility of LA measurements using different 3DE methods. One hundred and ninety-four patients were prospectively analyzed. Conventional 3DE and two semi-automatic 3DE algorithms (Tomtec™ and Dynamic Heart Model (DHM)) were used in 110 patients. Intra- and interobserver reproducibility and intervendor comparison were performed in additional patients' subsets. Forty patients underwent cardiac magnetic resonance (CMR). Feasibility was 100% for Tomtec, 98.2% for DHM, and 72.8% for conventional 3DE. Tomtec volumes were higher than 3DE and DHM (p < 0.001). Reproducibility was better for DHM (intraobserver LA maximum volume (LAmax) ICC 0.99 (95% CI 1.0-0.99), LA minimum volume (LAmin) 0.98 (95% CI 0.95-0.99), LApreA 0.96 (95% CI 0.91-0.98); interobserver LAmax ICC 0.98 (95% CI 0.96-0.99), LAmin 0.99 (95% CI 0.99-1.00), and LApreA 0.97 (95% CI 0.94-0.99)). Intervendor comparison showed differences between left ventricle (LV) software adapted for LA (p < 0.001). Tomtec underestimated the least LA volumes compared to CMR. These findings emphasize that dedicated software should be used for LA assessment, for consistent clinical longitudinal follow-up and research.

Insights From Atrial Fibrillation Genomics: From Bedside to Bench and Back Again

From the bedside of patients contributing samples to large genome-wide association studies for atrial fibrillation (AF), over 100 AF risk loci have been identified. The top locus is near a gene implicated in pulmonary vein formation; the ostia of the pulmonary veins harbor initiating triggers of AF, and isolation of these areas is the cornerstone of ablation therapies for AF. Transcriptomic studies suggest that AF is associated with impaired or overwhelmed responses to cell stress. A dual risk model proposes that in genetically-susceptible individuals, inadequate transcriptional responses to stress predispose to AF in later life. Drugs targeting metabolic, oxidative, or protein handling stress may be novel upstream agents to bring back to the bedside for study in the prevention of AF.

Calcium in the Pathophysiology of Atrial Fibrillation and Heart Failure

Atrial fibrillation (AF) is commonly associated with heart failure. A bidirectional relationship exists between the two-AF exacerbates heart failure causing a significant increase in heart failure symptoms, admissions to hospital and cardiovascular death, while pathological remodeling of the atria as a result of heart failure increases the risk of AF. A comprehensive understanding of the pathophysiology of AF is essential if we are to break this vicious circle. In this review, the latest evidence will be presented showing a fundamental role for calcium in both the induction and maintenance of AF. After outlining atrial electrophysiology and calcium handling, the role of calcium-dependent afterdepolarizations and atrial repolarization alternans in triggering AF will be considered. The atrial response to rapid stimulation will be discussed, including the short-term protection from calcium overload in the form of calcium signaling silencing and the eventual progression to diastolic calcium leak causing afterdepolarizations and the development of an electrical substrate that perpetuates AF. The role of calcium in the bidirectional relationship between heart failure and AF will then be covered. The effects of heart failure on atrial calcium handling that promote AF will be reviewed, including effects on both atrial myocytes and the pulmonary veins, before the aspects of AF which exacerbate heart failure are discussed. Finally, the limitations of human and animal studies will be explored allowing contextualization of what are sometimes discordant results.

Association Between Cardiovascular Magnetic Resonance-Derived Left Atrial Dimensions, Electroanatomical Substrate and NT-proANP Levels in Atrial Fibrillation

Background Enlargement of left atrial ( LA ) size indicates advanced disease stage in patients with atrial fibrillation ( AF ) and is associated with poor success of different AF therapies. Two dimensional echocardiographic LA measurements do not reliably reflect the true size of LA anatomy. The aim of the current study was: 1) to analyze cardiovascular magnetic resonance ( CMR )-derived LA dimensions and their association with low voltage areas ( LVA ); and 2) to investigate the association between these parameters and NT -pro ANP (N-terminal proatrial natriuretic peptide) levels. Methods and Results Patients undergoing first AF catheter ablation were included. All patients underwent CMR imaging (Ingenia 1.5T Philips) before intervention. CMR data ( LA volume, superior-inferior, transversal and anterior-posterior LA diameters) were measured in all patients. LVA were determined using high-density maps and a low voltage threshold <0.5 mV. Blood plasma samples from femoral vein were collected before catheter ablation. NT -pro ANP levels were studied using commercially available assays. There were 216 patients (65±11 years, 59% males, 56% persistent AF , 26% LVA ) included into analyses. NT -pro ANP levels in patients with LVA were significantly higher than in those without (median/interquartile range 22 [13-29] versus 15 [9-22] pg/mL, P=0.004). All CMR derived LA diameters correlated significantly with persistent AF ( r²=0.291-0.468, all P<0.001), LVA ( r²=0.187-0.306, all P<0.001), and NT -pro ANP levels ( r²=0.258-0.352, P<0.01). On logistic regression multivariable analysis, age (odds ratio=1.090, 95% confidence interval: 1.030-1.153, P=0.003), females (odds ratio=2.686, 95% confidence interval: 1.047-6.891, P=0.040), and LA volume (odds ratio=1.022, 95% confidence interval: 1.009-1.035, P=0.001) remained significant predictors for LVA . Conclusions Left atrial CMR parameters are associated with persistent AF , low voltage areas and NT -pro ANP levels. LA volume is the most significant predictor for LVA .

Left atrium remodeling predicts late recurrence of paroxysmal atrial fibrillation after second generation cryoballoon ablation

Background

Atrial fibrillation (AF) is the most common arrhythmia worldwide. Nowadays, AF ablation is a valuable treatment option. It has been shown that the left atrium (LA) diameter is a predictor of AF recurrence after cryoballoon ablation (CBA). Since it does not reflect the true LA size, we compared the role of different LA anatomical parameters using echocardiography for the prediction of AF recurrence after CBA.

Methods

We retrospectively included 209 patients (mean age 56.1 ± 13.6 years, male 62%) with paroxysmal AF undergoing CBA. A transthoracic echocardiography was performed in all patients.

Results

At a mean follow-up of 16.9 ± 6.3 months, AF recurred in 25.4% of the patients. LA anterior - posterior diameter (LAD), LA minimum volume (LAmin) and early AF recurrence were independent predictors of recurrence. Based on receiver operating characteristics, cut – off values for LAD and, LAmin were 41 mm, 23.69 mL, respectively. The negative predictive values for recurrence were 73% and 87.3% respectively. In patients with AF recurrence, a significant proportion (30.2%) showed LA longitudinal remodeling (LA superior – inferior diameter) even though classically measured LAD was normal.

Conclusions

Longitudinal LA remodeling plays an additional role for predicting AF recurrence after CBA, in patients without LAD dilation. Moreover, LAmin had a high negative predictive value and was an independent predictor of AF recurrence. Therefore, a more complete LA anatomical assessment allows a better prediction of AF recurrences after CBA.

Surface ECG and intracardiac spectral measures predict atrial fibrillation recurrence after catheter ablation

INTRODUCTION

Outcome of patients undergoing catheter ablation of atrial fibrillation (AF) varies widely. We sought to investigate whether parameters derived from the spectral analysis of surface ECG and intracardiac AF electrograms can predict outcome in patients referred for pulmonary vein isolation (PVI).

METHODS

We performed spectral analysis on the surface ECG and intracardiac electrograms from patients referred for AF ablation. After filtering and QRST subtraction, we measured the dominant frequency (DF), regularity index (RI) and the organizational index (OI) of fibrillatory electrograms and determined their value for predicting AF recurrence after ablation. A subjective, blinded prediction based on the surface ECG was also performed.

RESULTS

We analyzed data from 153 PVI procedures in 140 patients (67.1% with persistent or longstanding AF). In a multivariable model, DF in the right atrium (RA) and distal coronary sinus (CSd)-to-RA DF gradient predicted AF recurrence (OR, 3.52, P = 0.023 and OR, 0.2, P = 0.034, respectively). DF in RA and CSd to RA DF gradient had a good predictive value for PVI outcome (area under the curve [AUC] of 0.73, P = 0.007 and 0.74, P = 0.007, respectively). These performed better than the subjective predictions of experienced electrophysiologists ( P = 0.2).

CONCLUSIONS

Higher RA DF, lower CSd to RA DF gradient predicted recurrence after AF ablation. These spectral measures suggest a more remodeled atrial substrate and may provide simple tools for risk stratification or predict the need for additional substrate modification in patients referred for AF ablation.

Predictors of the paroxysmal atrial fibrillation recurrence following cryoballoon-based pulmonary vein isolation: Assessment of left atrial volume, left atrial volume index, galectin-3 level and neutrophil-to-lymphocyte ratio

Background

Cryoballoon-based pulmonary vein isolation (PVI) is a treatment option for atrial fibrillation (AF). Left atrial volume (LAV) and left atrial volume index (LAVi) are important parameters for long term success of PVI. Galectin-3 (Gal-3) and neutrophil to lymphocyte ratio (N/L ratio) are biomarkers to demonstrate the cardiac fibrosis and remodelling.

Methods

50 patients with symptomatic PAF despite ≥1 antiarrhythmic drug(s), who underwent PVI were enrolled. LAV, LAVi, Gal-3 and N/L ratio were calculated before ablation and after ablation at 6 and 12 months. According to AF recurrence patients were divided into two groups, recurrent AF (n = 14) and non-recurrent AF (n = 36).

Results

In both groups (recurrent and non-recurrent), initial and 12 months follow-up LAV values were 41.39 ± 18.13 ml and 53.24 ± 22.11 ml vs 48.85 ± 12.89 ml and 42.08 ± 13.85 (p = 0.037). LAVi were 20.9 ± 8.91 ml/m2 and 26.85 ± 11.28 ml/m2 vs 25.36 ± 6.21 and 21.87 ± 6.66 (p = 0.05) for recurrent and non-recurrent AF groups, respectively. In both groups PVI had no significant effect on serum Gal-3 levels and N/L ratio during 12 months follow-up. The comparison between two groups at the end of 12th month showed Gal-3 values of 6.66 ± 4.09 ng/ml and 6.02 ± 2.95 ng/ml (p = 0.516), N/L ratio values of 2.28 ± 1.07 10³/μl and 1.98 ± 0.66 10³/μl (p = 0.674).

Conclusion

LAV and LAVi are useful to predict the remodelling of the left atrium and AF recurrence after cryoballoon-based PVI. However, biomarkers such as Gal-3 and N/L ratio are not associated with AF recurrence.

Asymmetrical left atrial remodelling in atrial fibrillation: relation with diastolic dysfunction and long-term ablation outcomes

Aims

The association between anatomical left atrial (LA) remodelling and ventricular diastolic dysfunction (DD) in atrial fibrillation (AF) patients is not well studied. We aimed to examine the effect of DD on anatomic LA remodelling and their relation with ablation outcomes.

Methods and results

In 104 patients (58 ± 10 years, 69% male) referred for AF ablation, LA volume (LAV) was determined by computed tomography. A cutting plane, between the pulmonary vein (PV) ostia and the appendage and parallel to the posterior wall, divided LAV into anterior- (LA-A) and posterior-LA parts. The ratio of LA-A and LAV was defined as the LA asymmetry index (ASI). According to the current guidelines, the presence of DD was evaluated by echocardiography. Regression analysis was used to identify predictors of asymmetry changes and long-term success. Univariate linear regression revealed that ASI is associated with LAV, the presence of DD, and mitral regurgitation. Asymmetry index was higher in patients with DD (n = 35, 62 ± 5 vs. 59 ± 6%, P = 0.013) or mitral regurgitation (n = 67, 61 ± 6 vs. 58 ± 5%, P = 0.025). Multiple linear regression analysis showed that DD (B = 2.6, β = 0.207, 95% confidence interval, CI: 0.167-5.011, P = 0.036) and LAV (B = 0.037, β = 0.211, 95% CI: 0.003-0.071, P = 0.033) were the only factors independently associated with ASI (adjusted r2 = 0.92, F = 6.2, P = 0.003). Regression analysis showed that AF recurrence (33% after 24 months) is associated with asymmetric LA changes, while DD is not.

Conclusions

Left atrial symmetry changes are associated with DD and dilatation. Since DD could cause LA remodelling, appropriate early treatment should be considered for AF patients with DD, before geometrical changes occur.

Paroxysmal Atrial Fibrillation in Females: Understanding gender diferences

Background

The catheter ablation of atrial fibrillation (AF) is performed less frequently in women. In addition, there is divergent information in the literature regarding the effectiveness and safety for the ablative procedure to females.

Objectives

The objective of this study was to compare the clinical characteristics and outcomes in men and women undergoing paroxysmal atrial fibrillation (PAF) ablation.

Methods

Cohort study of patients undergoing first-ever PAF catheter ablation procedure refractory to antiarrhythmic drugs. The information was taken from patients’ records by means of a digital collection instrument and indexed to an online database (Syscardio®). Clinical characteristics and procedures were compared between each gender (M x F), adopting a level of statistical significance of 5%. The primary endpoint associated with efficacy was freedom from atrial arrhythmia over the follow-up time.

Results

225 patients were included in the study, 64 (29%) women and 161 (71%) men. Women presented more symptoms due to AF according to the CCS-SAF score (1.8 ± 0.8M x 2.3 ± 0.8F p = 0.02) and higher CHADS2 score compared to men (0.9 ± 0.8M x 1.2 ± 1F). Post-ablation recurrence occurred in 20% of the patients, with no difference based on gender (21% M x 20% F p = 0.52). The rate of complications was less than 3% for both groups (p = 0.98).

Conclusion

Women undergoing the first-ever PAF catheter ablation procedure present similar complication rate and clinical outcome compared to men. These findings suggest that the current underutilization of AF catheter ablation in women may represent a discrepancy in care.

The importance of integrated left atrial evaluation: From hypertension to heart failure with preserved ejection fraction

AIM

Functional analysis and measurement of left atrium are an integral part of cardiac evaluation, and they represent a key element during non-invasive analysis of diastolic function in patients with hypertension (HT) and/or heart failure with preserved ejection fraction (HFpEF). However, diastolic dysfunction remains quite elusive regarding classification, and atrial size and function are two key factors for left ventricular (LV) filling evaluation. Chronic left atrial (LA) remodelling is the final step of chronic intra-cavitary pressure overload, and it accompanies increased neurohormonal, proarrhythmic and prothrombotic activities. In this systematic review, we aim to purpose a multi-modality approach for LA geometry and function analysis, which integrates diastolic flow with LA characteristics and remodelling through application of both traditional and new diagnostic tools.

METHODS

The most important studies published in the literature on LA size, function and diastolic dysfunction in patients with HFpEF, HT and/or atrial fibrillation (AF) are considered and discussed.

RESULTS

In HFpEF and HT, pulsed and tissue Doppler assessments are useful tools to estimate LV filling pressure, atrio-ventricular coupling and LV relaxation but they need to be enriched with LA evaluation in terms of morphology and function. An integrated evaluation should be also applied to patients with a high arrhythmic risk, in whom eccentric LA remodelling and higher LA stiffness are associated with a greater AF risk.

CONCLUSION

Evaluation of LA size, volume, function and structure are mandatory in the management of patients with HT, HFpEF and AF. A multi-modality approach could provide additional information, identifying subjects with more severe LA remodelling. Left atrium assessment deserves an accurate study inside the cardiac imaging approach and optimised measurement with established cut-offs need to be better recognised through multicenter studies.

Persistent Atrial Fibrillation Ablation in Females: Insight from the MAGIC-AF Trial

INTRODUCTION

Atrial fibrillation (AF) ablation is less frequently performed in women when compared to men. There are conflicting data on the safety and efficacy of AF ablation in women. The objective of this study was to compare the clinical characteristics and outcomes in a contemporary cohort of men and women undergoing persistent AF ablation procedures.

METHODS AND RESULTS

A total of 182 men and 53 women undergoing a first-ever persistent AF catheter ablation procedure in The Modified Ablation Guided by Ibutilide Use in Chronic Atrial Fibrillation (MAGIC-AF) trial were evaluated. Clinical and procedural characteristics were compared between each gender. The primary efficacy endpoint was the 1-year single procedure freedom from atrial arrhythmia off anti-arrhythmic drugs. Women undergoing catheter ablation procedures were older than men (P < 0.001). The duration of AF and associated co-morbidities were similar between both genders. Single procedure drug-free atrial arrhythmia recurrence occurred in 53% of the cohort with no difference based on gender (men = 54%, women = 53%; P = 1.0). Procedural (P = 0.04), fluoroscopic (P = 0.02), and ablation times (P = 0.003) were shorter in women compared to men. Periprocedural complications and postablation improvement in quality of life were similar between men and women.

CONCLUSION

Women undergoing a first-ever persistent AF ablation procedure were older but had similar clinical outcomes and complications when compared with men.

Left Atrial Sphericity Index Predicts Early Recurrence of Atrial Fibrillation After Direct-Current Cardioversion: An Echocardiographic Study

BACKGROUND

Attempts to achieve rhythm control using direct-current cardioversion (DCC) are common in those with persistent atrial fibrillation (AF). Although often successful, AF recurs within 1 month in as many as 57% of patients. The aim of this study was to assess whether a baseline left atrial sphericity index (LASI) acquired by 2-dimensional transthoracic echocardiography (TTE) could be used as a predictor of AF recurrence after successful DCC.

HYPOTHESIS

A baselline LASI assessed by 2D TTE can predict AF recurrence after successful DCC in patients with persistent AF.

METHODS

A total of 124 consecutive patients with persistent AF lasting <120 days underwent successful DCC. Other than β-blockers, no other antiarrhythmic treatment was administered. Prior to DCC, all patients underwent thorough TTE, and LASI was calculated as the fraction of the left atrial width/length of the largest possible left atrial volume in a 4-chamber view. The primary outcome was a TTE-estimated baseline LASI as a predictor of AF recurrence after successful DCC for persistent AF.

RESULTS

Anatomically, a more spherical shape of the left atrium (LASI >0.9) proved to be a strong and independent predictor of AF recurrence, with an odds ratio between 4.1 (95% confidence interval: 1.6-11.9, P = 0.005) and 7.6 (95% confidence interval: 3.3-19.7; P = 7.2 × 10(-6) ). The receiver operating characteristic curve indicated good power for distinguishing between recurring and nonrecurring AF, and we chose a cutoff of 0.9 because high specificity was a priority for clinical reasons.

CONCLUSIONS

In conclusion, baseline LASI >0.9 was associated with significantly greater AF recurrence throughout the 12-month follow-up period.