scholarly journals Oesophageal thermal protection during AF ablation: effect on left atrial myocardial ablation lesion formation and patient outcomes

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
L Leung ◽  
A El Batran ◽  
G Dhillon ◽  
A Bajpai ◽  
Z Zuberi ◽  
...  
Keyword(s):  
Patient Outcomes ◽  
Left Atrial ◽  
Standard Care ◽  
Thermal Injury ◽  
Ablation Lesion ◽  
Rf Ablation ◽  
Lesion Formation ◽  
Private Company ◽  
Oesophageal Temperature ◽  
Af Ablation

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Dr Leung has received research support from Attune Medical (Chicago, IL). Dr Gallagher has received research funding from Attune Medical (Chicago, IL). Background Randomized evidence has shown that controlled oesophageal cooling is effective at reducing oesophageal thermal injury during radiofrequency (RF) ablation for atrial fibrillation (AF) compared to standard care. The effect of oesophageal cooling on ablation lesion formation in left atrial myocardium and patient outcomes at 12-months had not been previously studied. Purpose To determine the effect of oesophageal cooling on the formation of RF lesions, the ability to achieve procedural endpoints and long-term patient outcomes compared to standard care ablations. Methods Ablation results and patient outcomes from a double-blind randomized controlled trial were analysed (IMPACT trial NCT03819946). AF ablation was guided by Ablation Index technology (30W at 350-400 AI posteriorly, 40W at 450 AI anteriorly). A blinded 1:1 randomization assigned patients to the use of an oesophageal temperature control device to keep oesophageal temperature at 4 degrees during ablation or standard practice using a single-sensor temperature probe. Ablation parameters and 12-month outcomes were analysed. Results   We recruited 188 patients. Procedure and fluoroscopy times were similar. First pass pulmonary vein isolation and reconnection at the end of the waiting period were similar in both randomized groups (51/64 vs 51/68; p = 0.54 and 5/64 vs 7/68; p = 0.76, respectively). Posterior wall isolation was also similar: 24/33 vs 27/38; p = 0.88. Ablation effect on myocardial tissue, measured in impedance drop, was also similar: 8.6Ω (IQR: 6-11.8) vs 8.76Ω (IQR: 6-12.2; p = 0.25) and median catheter tip temperature was the same at 25.5 degrees. Arrhythmia recurrence was similar at 12 months (20.3% vs 26.8%, from 142 completed assessments; p = 0.66). Conclusions   Oesophageal cooling has been shown to be effective in reducing ablation-related oesophageal thermal injury during RF ablation. Ablation data show that this protection does not make it any more difficult to achieve standard procedural endpoints or clinical success at 12-months. Abstract Figure. Pyramid frequency plots of AI values

scholarly journals Patient outcomes after AF ablation using Ablation Index technology with oesophageal protection: insight from the IMPACT study

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
L Leung ◽  
A Bajpai ◽  
Z Zuberi ◽  
A Li ◽  
M Norman ◽  
...  
Keyword(s):  
Public Hospital ◽  
Thermal Injury ◽  
Control Group ◽  
Funding Source ◽  
Impact Study ◽  
Rf Ablation ◽  
Af Ablation ◽  
Ablation Index ◽  
The Impact

Abstract Background Atrio-oesophageal fistula formation accounts for the majority of AF ablation-related morbidity and mortality. Thermal injury to the oesophagus can be significantly reduced by application of oesophageal cooling for protection during AF ablation. The effect of this method of oesophageal protection in patients receiving radiofrequency (RF) ablation guided by Ablation Index technology is currently unknown. Objective To investigate the ability of a temperature control device to protect the oesophagus from ablation-related thermal injury in patients receiving AF ablation guided by Ablation Index technology. Methods The IMPACT study is a single-centre, prospective, double-blind randomized controlled trial, which investigated the ability of a controlled method of oesophageal cooling to protect the oesophagus from ablation-related thermal injury. The EnsoETM device was used to deliver oesophageal cooling. This method was compared in a 1:1 randomization to a control group of standard practice utilizing a single-sensor temperature probe. In the study group, the device was used to keep the luminal temperature at 4°C during RF ablation. All participants received AF ablation using Ablation Index technology at posterior and anterior settings (30W at 350–400 and 40W at 450–500, respectively). Endoscopic examination was performed within 7 days post-ablation and oesophageal injury was graded. The patient and the endoscopist were blinded to the randomization. Structured clinical follow up occurred after 3 months post-ablation; both patient and follow up clinician were blinded. Results We recruited 188 patients, of whom 120 underwent endoscopic evaluation. Thermal injury to the mucosa was significantly more common in the control group than in those receiving oesophageal protection (12/60 versus 2/60; P=0.008). There was no difference between groups in RF time, lesion duration, force, power and combined ablation index (P value range= 0.2–0.9). Procedure and fluoroscopy duration were similar (P=0.97, P=0.91 respectively). The majority of those who passed through the 1st follow up evaluation (n=136) did not have gastrointestinal or chest pain symptoms post ablation and there was no difference between the randomized groups. Only 4.4% overall had severe symptoms and they were poorly correlated against those who sustained mucosal lesions. AF recurrence was similar in both groups (8% vs 8.8%). There were 2 cases of vascular trauma needing intervention in the control group and 1 case of conservatively managed pericardial effusion in the protected group only. Clinical and endoscopy findings did not report any EnsoETM device-related trauma. Conclusion Thermal protection of the oesophagus significantly reduces ablation-related thermal injury compared to standard care when ablation is performed using radiofrequency with Ablation Index technology. This method of oesophageal protection is safe and does not compromise the efficacy of the ablation procedure. Endoscopy findings and patient symptoms. Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): 1. Public hospital: St. George's NHS Foundation Trust; 2. Private company: Attune Medical (Chicago, IL)

Real-time local impedance monitoring to assess tissue lesion during pulmonary vein isolation: a new tool for AF ablation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Di Cori ◽  
L Segreti ◽  
G Zucchelli ◽  
S Viani ◽  
F Tarasco ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Vein ◽  
Pulmonary Vein Isolation ◽  
Contact Force ◽  
Vascular Complications ◽  
Lesion Formation ◽  
Tissue Impedance ◽  
Af Ablation ◽  
Group 2 ◽  
Group 1

Abstract Background Contact force catheter ablation is the gold standard for treatment of atrial fibrillation (AF). Local tissue impedance (LI) evaluation has been recently studied to evaluate lesion formation during radiofrequency ablation. Purpose Aim of the study was to assess the outcomes of an irrigated catether with LI alghorithm compared to contact force (CF)-sensing catheters in the treatment of symptomatic AF. Methods A prospective, single-center, nonrandomized study was conducted, to compare outcomes between CF-AF ablation (Group 1) and LI-AF ablation (Group 2). For Group 1 ablation was performed using the Carto 3© System with the SmartTouch SF catheter and, as ablation target, an ablation index value of 500 anterior and 400 posterior. For Group 2, ablation was performed using the Rhythmia™ System with novel ablation catheter with a dedicated algorithm (DirectSense) used to measure LI at the distal electrode of this catheter. An absolute impedance drop greater than 20Ω was used at each targeted. According to the Close Protocol, ablation included a point by point pulmonary vein isolation (PVI) with an Inter-lesion space ≤5 mm in both Groups. Procedural endpoint was PVI, with confirmed bidirectional block. Results A total of 116 patients were enrolled, 59 patients in Group 1 (CF) and 57 in Group 2 (LI), 65 (63%) with a paroxismal AF and 36 (37%) with a persistent AF. Baseline patients features were not different between groups (P=ns). LI-Group showed a comparable procedural time (180±89 vs 180±56, P=0.59) but with a longer fluoroscopy time (20±12 vs 13±9 min, P=0.002). Wide antral isolation was more often observed in CF-Group (95% vs 80%, P=0.022), while LI-Group 2 required frequently additional right or left carina ablation (28% vs 14%, P=0.013). The mean LI was 106±14Ω prior to ablation and 92.5±11Ω after ablation (mean LI drop of 13.5±8Ω) during a median RF time of 26 [19–34] sec for each ablation spot. No steam pops or complications during the procedures were reported. The acute procedural success was 100%, with all PVs successfully isolated in all study patients. Regarding safety, only minor vascular complications were observed (5%), without differences between groups (p=0.97). During follow up, 9-month freedom from atrial fibrillation/atrial flutter/atrial tachycardia recurrence was 86% in Group 1 and 75% in Group 2 (P=0.2). Conclusions An LI-guided PV ablation strategy seems to be safe and effective, with acute and mid-term outcomes comparable to the current contact force strategy. LI monitoring could be a promising complementary parameter to evaluate not only wall contact but also lesion formation during power delivery. Procedural Outcomes Funding Acknowledgement Type of funding source: None

scholarly journals The Association of Pre-Existing Left Atrial Fibrosis with Clinical Variables in Patients Referred for Catheter Ablation of Atrial Fibrillation

2014 ◽  
Vol 8s1 ◽  
pp. CMC.S15036 ◽  
Author(s):  
Jane Dewire ◽  
Irfan M. Khurram ◽  
Farhad Pashakhanloo ◽  
David Spragg ◽  
Joseph E. Marine ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Left Atrial ◽  
Af Ablation ◽  
Group 4 ◽  
Significant Difference ◽  
History Of ◽  
Group 2 ◽  
Magnetic Resonance Imaging Mri ◽  
Left Atrial Fibrosis

Introduction Atrial fibrillation (AF) recurrence after ablation is associated with left atrial (LA) fibrosis on late gadolinium enhanced (LGE) magnetic resonance imaging (MRI). We sought to determine pre-ablation, clinical characteristics that associate with the extent of LA fibrosis in patients undergoing catheter ablation for AF. Methods and Results Consecutive patients presenting for catheter ablation of AF were enrolled and underwent LGE-MRI prior to initial AF ablation. The extent of fibrosis as a percentage of total LA myocardium was calculated in all patients prior to ablation. The cohort was divided into quartiles based on the percentage of fibrosis. Of 60 patients enrolled in the cohort, 13 had <5% fibrosis (Group 1), 15 had 5-7% fibrosis (Group 2), 17 had 8-13% fibrosis (Group 3), and 15 had 14-36% fibrosis (Group 4). The extent of LA fibrosis was positively associated with time in continuous AF, and the presence of persistent or longstanding persistent AF. However, no statistically significant difference was observed in the presence of comorbid conditions, age, BMI, LA volume, or family history of AF among the four groups. After adjusting for diabetes and hypertension in a multivariable linear regression model, paroxysmal AF remained independently and negatively associated with the extent of fibrosis (-4.0 ± 1.8, P = 0.034). Conclusion The extent of LA fibrosis in patients undergoing AF ablation is associated with AF type and time in continuous AF. Our results suggest that the presence and duration of AF are primary determinants of increased atrial LGE.

scholarly journals Thoracoscopic surgical atrial fibrillation ablation in patients with an extremely enlarged left atrium

2021 ◽  
Author(s):  
Jolien Neefs ◽  
Robin Wesselink ◽  
Nicoline W. E. van den Berg ◽  
Jonas S. S. G. de Jong ◽  
Femke R. Piersma ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrial ◽  
Antiarrhythmic Drugs ◽  
Primary Outcome ◽  
Volume Index ◽  
Substantial Part ◽  
Atrial Tachyarrhythmia ◽  
Af Ablation ◽  
Male Patients

Abstract Purpose Efficacy of pulmonary vein isolation (PVI) for atrial fibrillation (AF) decreases as left atrial (LA) volume increases. However, surgical AF ablation with unknown efficacy is being performed in patients with a giant LA (GLA). We determined efficacy of thoracoscopic AF ablation in patients with compared to without a GLA. Methods Patients underwent thoracoscopic PVI with additional left atrial ablations lines (in persistent AF) and were prospectively followed up. GLA was defined as LA volume index (LAVI) ≥ 50 ml/m2. Follow-up was performed with ECGs and 24-h Holters every 3 months. After a 3-month blanking period, all antiarrhythmic drugs were discontinued. The primary outcome was freedom of any atrial tachyarrhythmia ≥ 30 s during 2 years of follow-up. Results At baseline, 68 (15.4%) patients had a GLA (LAVI: 56.7 [52.4–62.8] ml/m2), while 374 (84.6%) had a smaller LA (LAVI: 34.8 [29.2–41.3] ml/m2). GLA patients were older (61.9 ± 6.9 vs 59.4 ± 8.8 years, p = 0.02), more often diagnosed with persistent AF (76.5% vs 58.6%, p = 0.008). Sex was equally distributed (with approximately 25% females). GLA patients had more recurrences compared to non-GLA patients at 2-year follow-up (42.6% vs 57.2%, log rank p = 0.02). Freedom of AF was 69.0% in non-GLA paroxysmal AF patients compared to 43.8–49.3% in a combined group of GLA and/or persistent AF patients(log rank p < 0.001). Furthermore, freedom was 62.4% in non-GLA male patients, compared to 43.8–47.4 in a combined group of GLA and/or female sex(log rank p = 0.02). Conclusion Thoracoscopic AF ablation is an effective therapy in a substantial part of GLA patients. Thoracoscopic AF ablation may serve as a last resort treatment option in these patients.

Abstract 501: Prevalence of Ascending Aorta Atherosclerosis as Detected by Echocardiography and Computed Tomography in Patients Referred for Atrial Fibrillation Ablation

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Efstratios Koutroumpakis ◽  
Benjamin Schwartz ◽  
John Espey ◽  
Elizabeth Rau ◽  
David Steckman ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Transthoracic Echocardiography ◽  
Left Atrial ◽  
Ascending Aorta ◽  
Plaque Burden ◽  
Aortic Atherosclerosis ◽  
Predictive Values ◽  
Af Ablation ◽  
Aortic Plaque ◽  
Af Recurrence

Introduction: The prevalence and significance of thoracic aorta atherosclerosis in AF patients has not been clearly defined in the literature. There are scant reports supporting an association of atherosclerotic aortic plaque burden with embolic phenomena and recurrence of AF post ablation. Two modalities of aortic atherosclerosis detection include computed tomography (CT) and echocardiography. Hypothesis: The prevalence of ascending aorta atherosclerosis in AF patients is high and CT performs better than transthoracic echocardiography in its detection. Methods: We investigated prevalence of ascending aorta atherosclerosis by CT and transthoracic echocardiography in 76 consecutive patients referred for AF ablation (67.1% males, 62.9 +/- 9.8 years old, 6.6% active smokers, 75% paroxysmal AF, 13.1% with LV ejection fraction (EF) <50%, 61.8% with hyperlipidemia, 55.8% with hypertension, 10.5% with diabetes, 2.6% with chronic kidney disease, and 1 patient with peripheral artery disease). The pre-ablation echocardiograms and cardiac CT scans, originally performed for left atrial mapping and evaluation of left atrial appendage thrombus, were reviewed in a blinded fashion for the presence of aortic atherosclerosis. Results: Out of 76 AF ablation patients, 27 (35.5%) had evidence of ascending aorta atherosclerosis by CT and 43 (56.6%) by echocardiography. Using CT as the gold standard, echocardiography had a sensitivity of 70.4% and a specificity of 51% in identification of ascending aorta atherosclerosis. Positive and negative predictive values were 44.2% and 75.8%, respectively. A total of 16 patients (21.1%) had AF recurrence post ablation, out of which 6 (37.5%) had evidence of aortic atherosclerosis on CT (vs 21/49 [42.9%] in the non-recurrence group). Conclusions: Ascending aorta atherosclerosis is common in patients referred for AF ablation. Transthoracic echocardiography likely overestimates its prevalence. Aortic atherosclerosis as detected by CT was not significantly associated with AF recurrence post ablation. More studies investigating clinical implications and best treatment approach to subclinical aortic therosclerosis in patients with AF are needed.

Abstract 12471: Optimal Prediction of Atrial Fibrillation Recurrence After Ablation: A Computational Anatomy Study

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Marta Varela ◽  
Felipe Bisbal ◽  
Ernesto Zacur ◽  
Esther Guiu ◽  
Antonio Berruezo ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrial ◽  
Complete Characterization ◽  
Statistical Shape Model ◽  
Patient Specific ◽  
Shape Variation ◽  
Global Features ◽  
Linear Discriminant ◽  
Af Ablation ◽  
Statistical Shape

Background: Left atrial structural remodelling, assessed by left atrial (LA) sphericity or antero-posterior diameter, has been shown to predict recurrence after atrial fibrillation (AF) ablation. The study aimed to perform a computational shape analysis of the LA to quantitatively characterise the LA shape remodelling process and identify metrics that optimally predict recurrence. Methods: Pre-procedural bright-blood MRIs of the LA of patients undergoing AF ablation were segmented. Patient-specific smooth 3D meshes were fitted to the segmentations. A statistical shape model of the LA was created and the global features underpinning the observed shape variation extracted as principal components (PCs). PCs were optimally combined to create non-empirical atlas-based metrics using linear discriminant analysis. Meshes depicting mean and extreme recurrent and non-recurrent LA shapes were also synthetized. The capability of different metrics to predict recurrence was evaluated using the area under the ROC curve (AUC) of a leave 1 out cross validation test. Results: In total, 111 patients were included. At 12 months follow-up, LA sphericity was the best predictor of recurrence (AUC: 0.66) over novel atlas-based metrics (AUC: 0.65). At 24 months, atlas-based metrics were the best predictors of recurrence (AUC: 0.66), outperforming a combination of sphericity and volume (AUC: 0.64), sphericity alone (AUC: 0.63) and any other traditional metric. Conclusions: Novel atlas-based metrics improve the prediction of recurrence at 2 years post-AF ablation. They allow a more complete characterization of the LA shape remodelling process, for example by allowing the synthesis of recurrent and non-recurrent LA shapes, which may contribute to patient stratification for AF ablation.

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