2023 Cardiac Society of Australia and New Zealand Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation

Catheter ablation for atrial fibrillation (AF) has increased exponentially in many developed countries, including Australia and New Zealand. This Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation from the Cardiac Society of Australia and New Zealand (CSANZ) recognises healthcare factors, expertise and expenditure relevant to the Australian and New Zealand healthcare environments including considerations of potential implications for First Nations Peoples. The statement is cognisant of international advice but tailored to local conditions and populations, and is intended to be used by electrophysiologists, cardiologists and general physicians across all disciplines caring for patients with AF. They are also intended to provide guidance to healthcare facilities seeking to establish or maintain catheter ablation for AF.

Clinical utility of oesophageal temperature monitoring in AF ablation: An updated meta-analysis and review of literature

BACKGROUND

Atrial fibrillation (AF) ablation can lead to oesophageal thermal injuries (ETI). These are thought to be the precursor of the much rarer but frequently fatal atrio-oesophageal fistulas. Many centers performing AF ablation routinely use oesophageal temperature monitoring (ETM). This meta-analysis aims to determine the utility of ETM in preventing ETI in the context of radiofrequency catheter ablation of AF.

METHODS

A systematic search of PubMed, Embase databases and Cochrane registry was performed comparing ETI between ETM and non-ETM strategies in AF ablation. Data on endoscopically determined ETI, AF recurrence, procedure time and ablation time were extracted. Statistical analyses including subgroup and covariate analyses were performed using random effect model in R platform.

RESULTS

ETI were similar in both ETM (n = 864) and non- ETM groups (n = 639) (RR 1.04, 95 % CI 0.34-3.23) across 12 studies. AF recurrence was statistically similar in both groups (IRR 0.92, 95 % CI 0.73-1.17) but showed a lower trend in non-ETM group. Ablation time was numerically lower in the ETM group and procedure time was numerically higher trend in the ETM group; but they were not statistically significant. Covariate analysis found that posterior wall ablation power setting, additional linear ablation, BMI, use of GA or prophylactic PPI after ablation had no significant correlation in the incidence of ETI.

CONCLUSION

ETM was not associated with a reduced incidence of ETI during AF ablation. Evidence supporting the routine use of ETM to reduce the risk of ETI or atrio-oesophageal fistulas is lacking.

Prevention of esophageal lesions during atrial fibrillation catheter ablation using esophageal temperature monitoring: A systematic review and meta-analysis

INTRODUCTION

The use of esophageal temperature monitoring (ETM) for the prevention of esophageal injury during atrial fibrillation (AF) ablation is often advocated. However, evidence supporting its use is scarce and controversial. We therefore aimed to review the evidence assessing the efficacy of ETM for the prevention of esophageal injury.

METHODS

We performed a meta-analysis and systematic review of the available literature from inception to December 31, 2022. All studies comparing the use of ETM, versus no ETM, during radiofrequency (RF) AF ablation and which reported the incidence of endoscopically detected esophageal lesions (EDELs) were included.

RESULTS

Eleven studies with a total of 1112 patients undergoing RF AF ablation were identified. Of those patients, 627 were assigned to ETM (56%). The overall incidence of EDELs was 9.8%. The use of ETM during AF ablation was associated with a non significant increase in the incidence of EDELs (12.3% with ETM, vs. 6.6 % without ETM, odds ratio, 1.44, 95%CI, 0.49, 4.22, p = .51, I2 = 72%). The use of ETM was associated with a significant increase in the energy delivered specifically on the posterior wall compared to patients without ETM (mean power difference: 5.13 Watts, 95% CI, 1.52, 8.74, p = .005).

CONCLUSIONS

The use of ETM does not reduce the incidence of EDELs during RF AF ablation. The higher energy delivered on the posterior wall is likely attributable to a false sense of safety that may explain the lack of benefit of ETM. Further randomized controlled trials are needed to provide conclusive results.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

Machine learning identifies esophageal luminal temperature patterns associated with thermal injury in catheter ablation for atrial fibrillation

INTRODUCTION

Luminal esophageal temperature (LET) monitoring during atrial fibrillation (AF) ablation is widely used to reduce the incidence of endoscopically detected esophageal lesion (EDEL). We sought to assess whether specific patterns of LET variation are associated with EDEL.

METHODS

A high-fidelity multisensor probe was used to record LET in AF patients undergoing radiofrequency ablation (RFA) or cryoballoon ablation (CBA). Explainable machine learning and SHapley Additive exPlanations (SHAP) analysis were used to predict EDEL and assess feature importance.

RESULTS

A total of 94 patients (38.3% persistent AF, 71.3% male, 72 RFA, and 22 CBA) were included. EDEL was detected in 11 patients (10 RFA and one CBA). In the RFA group, the highest LET recorded was similar between patients with and without EDEL (40.6 [40.1-41]°C vs. 40.2 [39.1-40.9]°C; p = .313), however, the rate of LET rise for the highest recorded peak was higher (0.08 [0.03-0.12]°C/s vs. 0.02 [0.01-0.05]°C/s; p = .033), and the area under the curve (AUC) for the highest peak was smaller (412.5 [206.8-634.1] vs. 588.6 [380.4-861.1]; p = .047) in patients who had EDEL. In case of CBA, the patient with EDEL had a faster LET decline (0.12 vs. 0.07 [0.02-0.14]°C/s), and a smaller AUC for the lowest trough (2491.3 vs. 2629.3 [1712.6-5283.2]). SHAP analysis revealed that a rate of LET change higher than 0.05°C/s and an AUC less than 600 were more predictive of EDEL in RFA.

CONCLUSION

The rate of LET change and AUC for the recorded temperature predicted EDEL, whereas absolute peak temperatures did not.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Comparative Safety of Pulsed Field Ablation and Cryoballoon Ablation Technologies for Pulmonary Vein Isolation in Patients with Paroxysmal Atrial Fibrillation: A Critical Literature Review and Indirect Treatment Comparison

INTRODUCTION

Cryoballoon ablation (CBA) is a standard catheter ablation technology with demonstrated clinical effectiveness for the treatment of paroxysmal atrial fibrillation (PAF); however, it can be associated with major adverse events, including phrenic nerve paralysis. Pulsed field ablation (PFA) is a novel, minimally thermal technology with comparable effectiveness and low safety risk. This study aimed to compare the safety profiles of PFA and CBA through critical analyses of the literature and indirect treatment comparisons.

METHODS

Studies were identified by searching the MEDLINE database and the Clinicaltrials.gov registry. Registered clinical trials and/or Food and Drug Administration Investigation Device Exemption (FDA IDE) studies evaluating PFA or CBA in adult patients with drug-refractory PAF between January 2008 and March 2023 were selected. Comparative safety between PFA and CBA was assessed for major and prespecified adverse events. Indirect comparisons were conducted using the proportion of patients experiencing adverse events and confirmed with single-arm meta-analyses and sensitivity analyses.

RESULTS

Data were extracted from three PFA publications including a total of 497 patients and six CBA studies including a total of 1113 patients. The analysis revealed that PFA was associated with significantly lower risk of major adverse events {risk difference - 4.3% [95% confidence interval (CI) - 5.8, - 2.8]; risk ratio 0.16 [95% CI 0.07, 0.45]} and prespecified adverse events [risk difference - 2.5% (95% CI - 4.4, - 0.5); risk ratio 0.53 (95% CI 0.31, 0.96)]. Meta-analyses confirmed the lower rate of major adverse events for PFA [0.4% (95% CI 0.0, 1.3)] vs. CBA [5.6% (95% CI 2.6, 8.6)] and prespecified adverse events for PFA [2.7% (95% CI 1.2, 4.1)] vs. CBA [5.8% (95% CI 2.7, 9.0)]. Sensitivity analyses exploring heterogeneity across studies confirmed robustness of the main analyses.

CONCLUSION

The findings of this study show that PFA has a more favorable safety profile than CBA, with significantly lower risks of major and prespecified adverse events. These indirect comparisons help contextualize the safety of PFA compared to CBA for the treatment of drug-refractory PAF in the absence of head-to-head studies.

Fecal calprotectin: A novel predictor of ulcerated esophageal injury after atrial fibrillation catheter ablation

BACKGROUND

Atrial esophageal fistula (AEF) is a lethal complication that can occur post atrial fibrillation (AF) ablation. Esophageal injury (EI) is likely to be the initial lesion leading to AEF. Endoscopic examination is the gold standard for a diagnosis of EI but extensive endoscopic screening is invasive and costly. This study was conducted to determine whether fecal calprotectin (Fcal), a marker of inflammation throughout the intestinal tract, may be associated with the existence of esophageal injury.

METHODS

This diagnostic study was conducted in a cohort of 166 patients with symptomatic AF undergoing radiofrequency catheter ablation from May 2020 to June 2021. Fcal tests were performed 1-7 days after ablation. All patients underwent endoscopic ultrasonography 1 or 2 days after ablation.

RESULTS

The levels of Fcal were significantly different between the EI and non-EI groups (404.9 µg/g (IQR 129.6-723.6) vs. 40.4 µg/g (IQR 15.0-246.2), p < .001). Analysis of ROC curves revealed that a Fcal level of 125 µg/g might be the optimal cut-off value for a diagnosis of EI, giving a 78.8% sensitivity and a 65.4% specificity. The negative predictive value of Fcal was 100% for ulcerated EI.

CONCLUSIONS

The level of Fcal is associated with EI post AF catheter ablation. 125 µg/g might be the optimal cut-off value for a diagnosis of EI. Negative Fcal could predict the absence of ulcerated EI, which could be considered a precursor to AEF.

Lower contact force predicts right pulmonary vein carina breakthrough after ablation index-guided pulmonary vein isolation using high-power short-duration

INTRODUCTION

Carina breakthrough (CB) at the right pulmonary vein (RPV) can occur after circumferential pulmonary vein isolation (PVI) due to epicardial bridging or transient tissue edema. High-power short-duration (HPSD) ablation may increase the incidence of RPV CB. Currently, the surrogate of ablation parameters to predict RPV CB is not well established. This study investigated predictors of RPV CB in patients undergoing ablation index (AI)-guided PVI with HPSD.

METHODS

The study included 62 patients with symptomatic atrial fibrillation (AF) who underwent AI-guided PVI using HPSD. Patients were categorized into two groups based on the presence or absence of RPV CB. Lesions adjacent to the RPV carina were assessed, and CB was confirmed through residual voltage, low voltage along the ablation lesions, and activation wavefront propagation.

RESULTS

Out of the 62 patients, 21 (33.87%) experienced RPV CB (Group 1), while 41 (66.13%) achieved first-pass RPV isolation (Group 2). Despite similar AI and HPSD, patients with RPV CB had lower contact force (CF) at lesions adjacent to the RPV carina. Receiver operating characteristic (ROC) curve analysis identified CF < 10.5 g as a predictor of RPV CB, with 75.7% sensitivity and 56.2% specificity (area under the curve: 0.714).

CONCLUSION

In patients undergoing AI-guided PVI with HPSD, lower CF adjacent to the carina was associated with a higher risk of RPV CB. These findings suggest that maintaining higher CF during ablation in this region may reduce the occurrence of RPV CB.

Safety of an esophageal deviator for atrial fibrillation catheter ablation

Background

Esophageal thermal injury is a complication of atrial fibrillation (AF) ablation, and it can be avoided by esophageal deviation during left atrial posterior wall radiofrequency catheter ablation.

Objective

This study aimed to evaluate the safety of a nitinol-based mechanical esophageal displacement device (MEDD) and its performance.

Methods

This preclinical safety study was conducted on 20 pigs, with 10 undergoing radiofrequency AF ablation using the MEDD and 10 serving as a control group under anticoagulation but without radiofrequency application. Esophageal traumatic injuries were classified from 0 to 4 and were grouped as absent (grade 0), minor (grade 1 or 2), moderate (grade 3), or major risk lesions (grade 4) by anatomopathological study. Grades 1 and 2 were considered acceptable. Fluoroscopy was used to measure displacement.

Results

Five (25%) pigs developed traumatic lesions, 4 with grade 1 and 1 with grade 2 (2-mm superficial ulcer). There was no difference in lesion occurrence between the radiofrequency and control groups (30% and 20%, respectively; P = .43). Under rightward displacement, the right edge moved 23.9 (interquartile range [IQR] 21.3-26.3) mm and the left edge moved 16.3 (IQR 13.8-18.4) mm (P < .001) from baseline. Under leftward displacement, the right edge moved 13.5 (IQR 10.9-15.3) mm and the left edge moved 16.5 (IQR 12.3-18.5) mm (P = .07). A perforation to the pharyngeal diverticulum occurred in 1 pig, related to an accidental extubation.

Conclusion

In pigs, the MEDD demonstrated safety in relation to esophageal tissue, and successful deviation. Esophageal traumatic injuries were acceptable, but improper manipulation led to pharyngeal lesion.

Role of oesophageal cooling in the prevention of oesophageal injury in atrial fibrillation catheter ablation: a systematic review and meta-analysis of randomized controlled trials

AIMS

To evaluate the efficacy of oesophageal cooling in the prevention of oesophageal injury in patients undergoing atrial fibrillation (AF) catheter ablation.

METHODS AND RESULTS

Comprehensive search of MEDLINE, EMBASE, and Cochrane databases through April 2022 for randomized controlled trials (RCTs) evaluating the role of oesophageal cooling compared with control in the prevention of oesophageal injury during AF catheter ablation. The study primary outcome was the incidence of any oesophageal injury. The meta-analysis included 4 RCTs with a total of 294 patients. There was no difference in the incidence of any oesophageal injury between oesophageal cooling and control [15% vs. 19%; relative risk (RR) 0.86; 95% confidence interval (CI) 0.31-2.41]. Compared with control, oesophageal cooling showed lower risk of severe oesophageal injury (1.5% vs. 9%; RR 0.21; 95% CI 0.05-0.80). There were no significant differences among the two groups in mild to moderate oesophageal injury (13.6% vs. 12.1%; RR 1.09; 95% CI 0.28-4.23), procedure duration [standardized mean difference (SMD) -0.03; 95% CI -0.36-0.30], posterior wall radiofrequency (RF) time (SMD 0.27; 95% CI -0.04-0.58), total RF time (SMD -0.50; 95% CI -1.15-0.16), acute reconnection incidence (RR 0.93; 95% CI 0.02-36.34), and ablation index (SMD 0.16; 95% CI -0.33-0.66).

CONCLUSION

Among patients undergoing AF catheter ablation, oesophageal cooling did not reduce the overall risk of any oesophageal injury compared with control. Oesophageal cooling might shift the severity of oesophageal injuries to less severe injuries. Further studies should evaluate the long-term effects after oesophageal cooling during AF catheter ablation.

Pearls and Pitfalls of Pulsed Field Ablation

Pulsed field ablation (PFA) was recently rediscovered as an emerging treatment modality for the ablation of cardiac arrhythmias. Ultra-short high voltage pulses are leading to irreversible electroporation of cardiac cells subsequently resulting in cell death. Current literature of PFA for pulmonary vein isolation (PVI) consistently reported excellent acute and long-term efficacy along with a very low adverse event rate. The undeniable benefit of the novel ablation technique is that cardiac cells are more susceptible to electrical fields whereas surrounding structures such as the pulmonary veins, the phrenic nerve or the esophagus are not, or if at all, minimally affected, which results in a favorable safety profile that is expected to be superior to the current standard of care without compromising efficacy. Nevertheless, the exact mechanisms of electroporation are not yet entirely understood on a cellular basis and pulsed electrical field protocols of different manufactures are not comparable among one another and require their own validation for each indication. Importantly, randomized controlled trials and comparative data to current standard of care modalities, such as radiofrequency- or cryoballoon ablation, are still missing. This review focuses on the "pearls" and "pitfalls" of PFA, a technology that has the potential to become the future leading energy source for PVI and beyond.

Gastro-Esophageal Reflux Disease and Paroxysmal Atrial Fibrillation Ablation

Patients undergoing ablation for atrial fibrillation may be at increased risk of developing gastroesophageal reflux disease. We prospectively studied the presence of symptomatic gastroesophageal reflux disease in naïve patients who underwent atrial fibrillation ablation.

METHODS

The presence of typical symptoms suggestive of gastroesophageal reflux disease was clinically assessed by the gastroenterologist at baseline and at 3 months after ablation. In addition to that, all patients underwent upper gastrointestinal endoscopy.

RESULTS

Seventy-five patients were included in two groups: 46 patients who underwent atrial fibrillation ablation (study group) and 29 patients without ablation (control group). Patients with atrial fibrillation ablation were younger (57.76 ± 7.66 years versus 67.81 ± 8.52 years; p = 0.001), predominantly male (62.2% versus 33.3%; p = 0.030) and with higher body mass index (28.96 ± 3.12 kg/m² versus 26.81 ± 5.19 kg/m²; p = 0.046). At three months after the ablation, in the study and control groups, there were 88.9% and 57.1% patients in sinus rhythm, respectively, (p = 0.009). Symptomatic gastroesophageal reflux disease was not more frequent in the study group (42.2% versus 61.9%; p = 0.220). There was no difference in terms of sinus rhythm prevalence in patients with versus without symptomatic gastroesophageal reflux disease (89.5% versus 88.5%; p = 0.709).

CONCLUSION

In this small prospective study, typical symptoms suggestive of gastroesophageal reflux disease were not more frequent three months following atrial fibrillation ablation.

Incidence of ablation-induced esophageal lesions and gastroparesis in patients undergoing ablation index guided high power short duration atrial fibrillation ablation

INTRODUCTION

Aim of this study was to evaluate the incidence of ablation-induced endoscopically detected esophageal lesions (EDEL) and gastroparesis in patients undergoing high-power short-duration (HPSD) atrial fibrillation (AF) ablation using different target ablation index (AI) values.

METHODS AND RESULTS

Consecutive patients undergoing AF ablation were included. Radiofrequency (RF) ablation was performed using HPSD ablation (50 W, target AI of 320 and 350 (group 1) and 380 (group 2) at posterior wall). Postablation endoscopy was performed in all patients. In total, 233 patients (66.8 ± 10 years; 52% male) were included consecutively (n = 137 patients in group 1 and n = 96 patients in group 2). Mean AI values und RF time at posterior wall was significantly higher and longer in group 2 compared to group 1 patients (413 ± 9 vs. 392 ± 19 AI, p < 0.01; 9.0 ± 0.8 s vs. 7.8 ± 0.7 s, p < 0.01). Esophageal endoscopy revealed esophageal lesions or gastroparesis in 43 of 233 patients (18.5%) in the total cohort (13.1% in group 1 and 26.0% in group 2; p = 0.02). Incidence of EDEL was 8.0% and 13.5% in group 1 and group 2, respectively. According to logistic analysis incidence of EDEL and/or gastroparesis was significantly lower in patients with a higher body mass index and higher in group 2 patients compared to group 1 patients.

CONCLUSION

The incidence of EDEL or gastroparesis in patients undergoing HPSD AF ablation was 18.5% in the total cohort. The risk of EDEL and gastroparesis was associated with a higher AI target value of 380 compared to 320 and 350 at posterior wall and was reversely associated with body mass index.

Oesophageal safety in voltage-guided atrial fibrillation ablation using ablation index or contact force only: a prospective comparison

AIMS

Left atrial ablation using radiofrequency (RF) is associated with endoscopically detected thermal oesophageal lesions (EDELs). The aim of this study was to compare EDEL occurrence after conventional contact force-guided (CFG) RF ablation vs. an ablation index-guided (AIG) approach in clinical routine of voltage-guided ablation (VGA). Predictors of EDEL were also assessed.

METHODS AND RESULTS

This study compared CFG (n = 100) with AIG (n = 100) in consecutive atrial fibrillation ablation procedures, in which both pulmonary vein isolation and VGA were performed. In the AIG group, AI targets were ≥500 anteriorly and ≥350-400 posteriorly. Upper endoscopy was performed after ablation.The CFG and AIG groups had comparable baseline characteristics. The EDEL occurred in 6 and 5% (P = 0.86) in the CFG and AIG groups, respectively. Category 2 lesions occurred in 4 and 2% (P = 0.68), respectively. All EDEL healed under proton pump inhibitor therapy. The AI > 520 was the only predictor of EDEL [odds ratio (OR) 3.84; P = 0.039]. The more extensive Category 2 lesions were predicted by: AI max > 520 during posterior ablation (OR 7.05; P = 0.042), application of posterior or roof lines (OR 5.19; P = 0.039), existence of cardiomyopathy (OR 4.93; P = 0.047), and CHA2DS2-VASc score (OR 1.71; P = 0.044). The only Category 2 lesion with AI max < 520 (467) occurred in a patient with low body mass index.

CONCLUSIONS

Both methods were comparable with respect to clinical complications and EDEL. In consideration of previous reconnection data and our study results regarding oesophageal safety, optimal AI target range might be between 400 and 450.

Radiofrequency Pulmonary Vein Isolation without Esophageal Temperature Monitoring: Contact-Force Characteristics and Incidence of Esophageal Thermal Damage

Esophageal thermal lesions following pulmonary vein isolation (PVI) for atrial fibrillation (AF) potentially harbor lethal complications. Radiofrequency (RF)-PVI using contact force-technology can reduce collateral damage. We evaluated the incidence of endoscopically detected esophageal lesions (EDEL) and the contribution of contact force to esophageal lesion formation without esophageal temperature monitoring. One hundred and thirty-one AF patients underwent contact force-guided RF-PVI. Contact force, energy, force-time-integral, and force-power-time-integral were adopted. During PVI at the posterior segment of the wide antral circumferential line, limits were set for energy (30 W), duration (30 s) and contact force (40 g). Ablations were analyzed postero-superior and -inferior around PVs. Endoscopy within 120 h identified EDEL in six patients (4.6%). In EDEL(+), obesity was less frequent (17% vs. 68%, p = 0.018), creatinine was higher (1.55 ± 1.18 vs. 1.07 ± 0.42 mg/dL, p = 0.016), and exclusively at the left postero-inferior site, force-time-integral and force-power-time-integral were greater (2973 ± 3267 vs. 1757 ± 1262 g·s, p = 0.042 and 83,547 ± 105,940 vs. 43,556 ± 35,255 g·J, p = 0.022, respectively) as compared to EDEL(-) patients. No major complications occurred. At 12 months, arrhythmia-free survival was 74%. The incidence of EDEL was low after contact force-guided RF-PVI. Implementing combined contact force-indices on the postero-inferior site of left-sided PVs may reduce EDEL.

Lessons Learned from a Delayed Diagnosis of Atrioesophageal Fistula: A Multidisciplinary Approach

Atrioesophageal fistulas are a rare complication of radiofrequency ablation that requires rapid identification and emergent surgical repair to prevent morbidity and mortality. We report a case of a 32-year-old man with atrial fibrillation presenting with chest pain followed by rapidly progressive sepsis and embolic cerebrovascular accident 23 days after radiofrequency ablation. Subtle initially overlooked findings on multiple computed tomography caused a delay in diagnosis. Atrioesophageal fistulas remain diagnostically challenging. A high index of suspicion coupled with serial computed tomography of the chest with intravenous and oral contrast reviewed by a multimodal team is essential to make a timely diagnosis. This article is protected by copyright. All rights reserved.

Safety aspects of very high power very short duration atrial fibrillation ablation using a modified Radiofrequency RF-Generator: Single center experience

INTRODUCTION

High power short duration ablation proved to be an effective and safe ablation technique for atrial fibrillation (AF). In former case series a significant amount of post-ablation coagulation at the catheter tip as well as silent cerebral lesions in post-procedural cerebral MRI have been identified in patients undergoing de-novo AF ablations with very high power 90 W short duration (vHPvSD) ablations using the QDot ablation catheter in combination with a novel RF-generator (nGEN, BiosenseWebster). Therefore, the RF generator software has been recently modified.

METHODS AND RESULTS

Consecutive patients undergoing a first AF ablation including pulmonary vein isolation (PVI) with vHPvSD (90 W, with a predefined ablation time of 3 seconds at posterior LA wall sites and 4 seconds at other ablation sites) using the QDOT Micro ablation catheter (Biosense Webster) in conjunction with the technically modified nGEN RF generator (software V1c; Biosense Webster) were included. Procedural characteristics including first-pass isolation per pulmonary vein (PV) pair and early reconnection location within the 30-minute waiting period were recorded. In all patients post-ablation endoscopy to document any thermal esophageal injury (EDEL) and in eligible patients a cerebral magnetic resonance imaging (cMRI) to detect silent cerebral events (SCE)/lesions (SCL) were performed. All acute procedure related complications were recorded during the time until hospital discharge. Furthermore, short-term and mid-term success after 3 and 6 to 12 months of follow-up was investigated. In total, 34 consecutive patients (67±9 years; 62% male; 68% paroxysmal AF) were included. First-pass isolation of all PVs was achieved in 6/34 (18%) patients. First-pass isolation was seen in 37/68 (54%) of PV pairs. Early reconnection occurred in 11 (32%) patients (including reconnections at posterior LA wall sites n=6 and at non-posterior sites n=5). No patient had an EDEL (0%). In 6/23 (26%) patients undergoing post-ablation cerebral MRI SCE were identified. In 6 patients coagulation on the catheter tip was detected at the end of the procedure. No further peri- or post-procedural complications were detected. Early AF recurrence before discharge was seen in 1/34 (3%) of the patients included in this study. Within 3 months 10/34 (29%) revealed AF recurrence during blanking period. After a mean follow-up of 7 months 31/34 (88%) patients revealed sinus rhythm.

CONCLUSION

AF ablation using 90W vHPvSD with a specialized ablation catheter in conjunction with a recently modified RF-generator was associated with no EDEL in the whole study cohort and 26% SCE in a subgroup of patients undergoing acute post-ablation cerebral MRI. Accordingly to our previously published results, a relevant number of catheter tip coagulations was identified in this patient cohort even after modifications of the RF-generator. The vHPvSD ablation technique using the present and the previous generator seems to be associated with a very low rate of esophageal injury. However, the recently revised generator software also produced a relevant number of catheter tip coagulum formation and SCE. This article is protected by copyright. All rights reserved.

Acute oesophageal safety of high-power short duration with 50 W for atrial fibrillation ablation

Aims

Pulmonary vein isolation (PVI) using radiofrequency (RF) ablation is an effective treatment option for patients with atrial fibrillation (AF). This study aims to investigate the safety of high-power short duration (HPSD) with emphasis on oesophageal lesions after PVI.

Methods and results

Consecutive patients undergoing AF ablation with HPSD (50 W; ablation index (AI)-guided; target AI 350 for posterior wall ablation, AI 450 for anterior wall ablation) using the ThermoCool SmartTouch SF catheter were included. Patients underwent post-ablation oesophageal endoscopy to detect and categorize thermal oesophageal injury (EDEL). Occurrence and risk factors of oesophageal lesions and perforating complications were analysed. A total of 1033 patients underwent AF ablation with HPSD. Of them, 953 patients (67.6 ± 9.6 years; 58% male; 43% paroxysmal AF; 68% first PVI) underwent post-procedural oesophageal endoscopy and were included in further analyses. Median procedure time was 82.8 ± 24.4 min with ablation times of 16.1 ± 9.2 min. Thermal oesophageal injury was detected in 58 patients (6%) (n = 29 Category 1 erosion, n = 29 Category 2 ulcerous). One patient developed oesophageal perforation (redo, 4th AF ablation). No patient died. Using multivariable regression models, increased total ablation time [odds ratio (OR) 1.029, P = 0.010] and history of stroke (OR 2.619, P = 0.033) were associated with increased incidence of EDEL after AF ablation, whereas increased body mass index was protective (OR 0.980, P = 0.022).

Conclusion

Thermal oesophageal lesions occur in 6% of HPSD AF ablations. The risk for development of perforating complications seems to be low. Incidence of atrio-oesophageal fistula (0.1%) is comparable to other reported series about RF ablation approaches.

Esophageal temperature during atrial fibrillation ablation poorly predicts esophageal injury: An observational study

Background

Esophageal injury (EI) remains a concern when performing pulmonary vein isolation (PVI) using the high-power short-duration (HPSD) technique.

Objective

We aim to indicate that high esophageal temperature during HPSD PVI does not correlate with positive esophageal endoscopy (EGD) findings.

Methods

A retrospective observational study was performed on 43 patients undergoing PVI using HPSD (50 W for 6–7 seconds per lesion) at Tulane Medical Center from July 2020 to January 2021. Esophageal temperature was monitored throughout the procedure using a temperature probe and patients underwent EGD the following day. Small ulcers, nonbleeding erosions, erythema, and/or esophagitis were considered positive EGD findings.

Results

Mean age was 64.9 years; 46.5% of the patients were female. Eleven patients had positive EGD findings (group 1) and 32 patients had normal EGD (group 2). There was no statistical difference in mean esophageal peak temperature between group 1 and group 2 (43.9°C ± 2.9°C and 42.5°C ± 2.3°C, respectively, P = .17). There was no association between positive EGD results and esophageal temperature during PVI. Mean baseline esophageal temperature was similar in both groups (36.1°C, P = .78). Average contact force (P = .53), ablation time (P = .67), age (P = .3096), sex (P = .4), body mass index (P = .14), and other comorbidities did not correlate with positive endoscopy results. We found positive correlation between the distance of the left atrium (LA) to esophagus and positive EGD (P = .0001).

Conclusion

EI during HPSD PVI does not correlate to esophageal temperature changes during ablation. However, esophageal injury does correlate to a shorter proximity of the esophagus to the LA.

Incidence, epidemiology, diagnosis and prognosis of atrio-oesophageal fistula following percutaneous catheter ablation: a French nationwide survey

AIMS

Rate, incidence, risk factors, and optimal management of atrio-oesophageal fistula (AOF) after catheter ablation for atrial fibrillation (AF) remain obscure.

METHODS AND RESULTS

All French centres performing AF ablation were identified and surveys were sent concerning the number of procedures, eventual cases of AOF, and characteristics of such cases. Eighty-two of the 103 centres (80%) performing AF ablation in France were included, with a total of 129 286 AF ablations since 2006 (93% of the whole procedures in France). Thirty-three AOF were reported (reported rate 0.026% per procedure) with a stable reported annual incidence despite the increasing number of procedures. Sensitivity of computed tomography (CT) scan for AOF was 81%. Mortality was 60%, significantly lower in case of surgical corrective therapy (31 vs. 93%, P = 0.001).

CONCLUSION

The reported rate of AOF after AF ablation in this nationwide survey was 0.026%, with a stable reported annual incidence over time. A normal CT scan does not rule out the diagnosis and should be repeated in case of suspicion. Prognosis remains poor with a mortality of 60% and crucially dependant of immediate surgical correction. No clear protective strategy has been proven effective.

Atrio-oesophageal fistula following atrial fibrillation ablation: how to manage this dreaded complication?

OBJECTIVES

Atrio-oesophageal fistula is a rare but serious complication of radiofrequency catheter ablation of atrial fibrillation. Therapeutic options are surgery, oesophageal stenting and conservative treatment (antibiotics and anticoagulation). However, there are no guidelines available. Since no article dwells on the technical considerations of this surgery, we aim to present here our experience and share our surgical approach.

METHODS

Between January 2012 and March 2020, all consecutive patients treated for atrio-oesophageal fistula following radiofrequency catheter ablation of atrial fibrillation at our institution were analysed retrospectively. The diagnosis was made on a set of clinical and radiological signs. All patients benefitted from a combined approach involving both digestive and cardiac surgeons. Femoro-femoral peripheral cardiopulmonary by-pass was used. The surgical approach was a right posterolateral thoracotomy. Atrial repair was done on fibrillating heart without cross-clamping, using a left atriotomy. Digestive management consisted of a total oesophagectomy.

RESULTS

We identified 6 patients with this complication. The median age was 53 [34-72] years. Symptoms were neurological symptoms, fever and chest pain. Diagnostic modalities were cerebral imaging, chest CT and transthoracic echocardiogram. Atrial repair consisted in a suture of the atrium or by using a pericardial patch. With a median follow-up of 3.1 [0.1-7.7] years, only one patient died during the follow-up.

CONCLUSIONS

Our experience shows that an aggressive surgery with a large resection of the oesophagus and left atrial repair by right thoracotomy in the same time provides good results. The ability to involve simultaneously both experienced digestive and cardiac surgical teams is the key for this strategy.

Impact of proton pump inhibitors on mortality and severe esophageal injury after catheter ablation for atrial fibrillation: a nationwide retrospective study using propensity score matching

Studies on the protective effects of proton pump inhibitors (PPIs) on mortality and severe esophageal injury after catheter ablation for atrial fibrillation are lacking. However, some reports have recommended use of PPIs for prophylaxis against esophageal injury. We investigated the effects of PPIs on mortality and severe esophageal injury after ablation. We retrospectively extracted data for adult in-patients who received catheter ablation with a diagnosis of atrial fibrillation from July 2010 to March 2018. The patients were divided into two groups: with PPI (PPI group) and without PPI (non-PPI group) administration before or on the day of ablation. The primary composite outcome was all-cause 30-day mortality and incidence of severe esophageal injury with complication (cardiac tamponade, ischemic stroke, or sepsis) within 30 days of ablation. Secondary outcomes included incidence of cardiac tamponade, ischemic stroke, and sepsis within 30 days of ablation. Propensity score matching was performed to compare the primary and secondary outcomes between the two groups. We identified 141,649 eligible patients, comprising 62,558 in the PPI group and 79,091 in the non-PPI group. Propensity score-matching analysis showed that PPI use was not associated with reduced proportion of the primary outcome (adjusted odds ratio 1.02; 95% confidence interval 0.71-1.47). PPI use may not be beneficial for reducing mortality or severe complications.

The frequency of gastroesophageal reflux when radiofrequency catheter ablation procedures for atrial fibrillation under general anesthesia with a supraglottic device: Observational pilot study

Gastroesophageal reflux (GER) in radiofrequency catheter ablation (RFCA) occurs due to vagal plexus damage during pulmonary vein isolation. We hypothesized that the frequency of GER in the oropharynx will be less compared to other areas (low-esophagus, mid-esophagus). We confirmed the frequency of GER before and after RFCA in 3 areas.We studied 30 patients who were scheduled for RFCA under general anesthesia. Anesthesia was performed using supraglottic devices (SGD) with a suction port. Two esophageal temperature probes capable of suction and measuring temperature were inserted through the suction port. The pH of the 3 areas was measured before and after the RFCA at 3 areas (mid-esophagus, low-esophagus, and oropharynx).GER was observed in 13 of 30 patients (43%). In one patient, it was observed in the oropharynx, in 4 patients it was observed in the mid-esophagus, and in 13 patients, it was observed in the low-esophagus. For patients with GER at the oropharynx and mid-esophagus, it was also observed at the low-esophagus. The difference in the pH before and after the RFCA was not significant at the oropharynx and mid-esophagus (P = .726 and P = .424, respectively), but it was significantly different at the low-esophagus (P < .001). The total ablation time was longer in the GER group compared to the non-GER group (P = .021).GER after RFCA occurred in 43% of patients, only 1 patient in the oropharynx. And aspiration pneumonia after SGD extubation did not occur. Therefore, the use of SGDs in RFCA does not completely eliminate the possibility of aspiration, so care should be taken.

Incidence of ablation-induced esophageal injury associated with high-power short duration temperature-controlled pulmonary vein isolation using a specialized open-irrigated ablation catheter: A retrospective single-center study

INTRODUCTION

To evaluate short-term efficacy and incidence of ablation-induced endoscopically detected esophageal injury in patients undergoing high-power, short-duration (HPSD) pulmonary vein isolation using a novel irrigated radiofrequency ablation catheter and ablation generator setup.

METHODS AND RESULTS

Atrial fibrillation (AF) patients, who underwent AF ablation using an irrigated radiofrequency ablation catheter specifically designed for a HPSD ablation approach (50 W, with a target Ablation Index of 350 at posterior wall), received postablation esophageal endoscopy after ablation. In total 45 consecutive patients (67 ± 10 years; 58% male; 42% paroxysmal AF) undergoing AF ablation using a specialized ablation catheter (QDOT) were included in the study. Thirty-one of 45 patients (69%) underwent a first-time pulmonary vein isolation (Group 1, 67 ± 11 years; 55% male; 48% paroxysmal AF). Fourteen patients (31%) underwent a redo AF procedure (Group 2, 66 ± 8 years; 64% male; 29% paroxysmal AF). Patients undergoing first-time pulmonary vein isolation were included in the final analysis. In these patients an endoscopically detected esophageal lesion (EDEL) was detected in 5 of 31 (16%) patients (erosion n = 2, ulcer n = 3). Mean contact force at posterior wall ablation sites was significantly lower in patients with postprocedural EDEL compared with patients without EDEL (11.9 ± 0.8 g vs. 15.6 ± 4.7 g).

CONCLUSION

PVI using a specialized high-power ablation catheter in conjunction with a HPSD ablation approach results in a 16% incidence of EDEL in first AF ablation candidates. Future studies evaluating high-power short duration ablation strategies should include esophageal endoscopy to estimate the risk of clinically relevant esophageal complications.

Incidence of Esophageal Thermal Injury Using a Safety Protocol During Atrial Fibrillation Ablation

Objective: Catheter ablation has been a common procedure used for the management of atrial fibrillation (AF). Atrioesophagel fistula (AEF) is one of the most feared complications of AF ablation. Although it is a rare complication, severe esophageal thermal injury must be avoided. It is important to describe a safe method of preventing esophageal injuries without increasing AF recurrence. Methods: A retrospective cohort study of consecutive patients who underwent radiofrequency AF catheter ablation during 1 year-period wa conducted. One hundred and four patients were enrolled divided in two groups: one with a maximum recorded esophageal temperature (ET) < 38 °C and other with a maximum recorded ET ≥ 38 °C. The primary endpoint was detection of endoscopic esophageal lesions after AF ablation and the secondary endpoint was AF recurrence according to the maximum ET reached during the procedure. Results: The maximum ET was on average 37.3 ± 1.0 °C. Only 4 (3.8%) patients had esophageal lesion diagnosed by upper gastrointestinal endoscopy. There were no cases of esophageal perforation. The AF recurrence rate was 9.6% during the follow-up (10 patients, 3 from the ET max < 38 °C group and 7 from the ET max ≥ 38 °C group; p = 0.181). The maximum ET was not associated with AF recurrence after catheter ablation (OR = 1.65, 95% CI = 0.84-3.24, p = 0.14). Conclusions: A low incidence of esophageal injury after AF ablation with the use of a specific esophageal protection protocol was found. There was no esophageal perforation. The AF recurrence rate was similar to that described in the literature.

Current Status of Esophageal Protection

Catheter ablation of atrial fibrillation necessitates ablation on the posterior left atrium. The anterior esophagus touches the posterior left atrium, although its course is highly variable. The proximity of the left atrium to the esophagus confers risk of injury with radiofrequency and cryoablation owing to the heat transfer that occurs with thermal ablation. Early detection of esophageal temperature changes with probes may decrease the extent of damage to the esophagus, but evidence is mixed. Avoiding ablation on the esophagus with esophageal deviation and modifying ablation approaches may decrease the risk of injury.

Risk of esophageal thermal injury during catheter ablation for atrial fibrillation guided by different ablation index

BACKGROUND

During ablation for atrial fibrillation (AF), energy delivery toward the left atrial posterior wall may cause esophageal injury (EI). Ablation index (AI) was introduced to estimate ablation lesion size, however, the impact of AI technology on the risk of EI has not been explored.

METHOD

From March 2019 to December 2019, 60 patients with paroxysmal AF undergoing first-time ablation were prospectively enrolled. The first 30 consecutive patients were ablated with the AI target value of 400 (AI-400 group), and the later 30 consecutive patients were ablated with the AI target value of 350 at the posterior wall (AI-350 group). Endoscopic ultrasonography was used to evaluate EI postablation. EI was classified as a category 1 (erythema or erosion) or a category 2 (hematoma or ulceration).

RESULTS

Compared with the AI-400 group (59.9 ± 8.4 years; male, 60%), the AI-350 group (59.1 ± 9.9 years; male, 50%) had a lower incidence of EI (3.3% vs 26.7%, P = .03). There was no significant difference in the percentage of first-pass PVI between the AI-400 group and the AI-350 group (left PVI: 80% vs 73.4%, P = .54; right PVI: 80% vs 60%, P = .1). Neither ablation time nor fluoroscopy time was significantly different between the AI-400 group and the AI-350 group.

CONCLUSIONS

AF ablation guide by AI target value of 350 may reduce esophageal thermal injury and has a similar efficiency on the acute success rate of first-pass PVI compared with an AI target value of 400 at the posterior wall.

Management of Atrio-esophageal Fistula Induced by Radiofrequency Catheter Ablation in Atrial Fibrillation Patients: a Case Series

Atrio-esophageal fistula (AEF) is one of the most devastating complication of radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) and surgical repair is strongly recommended. However, optimal surgical approach remains to be elucidated. We retrospectively reviewed AEF cases that occurred after RFCA in a single center and evaluated the clinical results of different surgical approach. Surgical or endoscopic repair was attempted in five AF patients who underwent RFCA. Atrio-esophageal fistula and mediastinal infection was not controlled in the patient who underwent endoscopic repair eventually died. Lethal cerebral air embolism occurred two days after surgery in a patient who underwent esophageal repair only. Primary surgical repair of both the left atrium (LA) and esophagus was performed in the remaining three patients. Among these three patients, two underwent external LA repair and the remaining had internal LA repair via open-heart surgery. External repair of the LA was unsuccessful and one patient dies and another had to undergo second operation with internal repair of the LA. The patient who underwent internal LA repair during the first operation survived without additional surgery. Furthermore, we applied veno-arterial extracorporeal membrane oxygenation (VA-ECMO) with artificial induction of ventricular fibrillation in this patient to prevent air and septic embolism and she had no neurologic sequelae. In summary, surgical correction can be considered preferentially to correct AEF. Open-heart surgical repair of LA from the internal side seems to be an acceptable surgical method. Application of VA-ECMO with artificial induction of ventricular fibrillation might be effective to prevent air and septic embolism.

Characteristics of Atrial Fibrillation Patients Suffering Esophageal Injury Caused by Ablation for Atrial Fibrillation

The close proximity of esophagus to the left atrial posterior wall predisposes esophagus to thermal injury during catheter ablation for atrial fibrillation (AF). In this retrospective study, we aimed to investigate risk factors of esophageal injury (EI) caused by catheter ablation for AF. Patients who underwent first-time AF ablation from July 2013 to June 2018 were included. The esophagus was visualized by oral soluble contrast during ablation for all patients and a subset of patients were selected to undergo endoscopic ultrasonography (EUS) to estimate EI post ablation. Degree of EI was categorized as Kansas City classification: type 1: erythema; type 2: ulcers (2a: superficial ulcers; 2b: deep ulcers); type 3: perforation (3a: perforation without communication with the atria; 3b: atrioesophageal fistula [AEF]). Of 3,852 patients, 236 patients (61.5 ± 9.7 years; male, 69%) received EUS (EUS group) and 3616 (63.2 ± 10.9 years; male, 61.1%) without EUS (No-EUS group). In EUS group, EI occurred in 63 patients (type 1 EI in 35 and type 2 EI in 28), and no type 3 EI was observed during follow up. In a multivariable logistic regression analysis, an overlap between the ablation lesion and esophagus was an independent predictor of EI (odds ratio, 21.2; 95% CI: 6.23–72.0; P < 0.001). In No-EUS group, esophagopericardial fistula (EPF; n = 3,0.08%) or AEF (n = 2,0.06%) was diagnosed 4–37 days after ablation. In 3 EPF patients, 2 completely recovered with conservative management and 1 died. Two AEF patients died. Ablation at the vicinity of the esophagus predicts risk of EI. EUS post ablation may prevent the progression of EI and should be considered in management of EI. It remains challenging to identify patients with high risk of EI.

Relevance of esophageal position and temperature on thermal injuries and rhythm outcome in atrial fibrillation ablations

BACKGROUND

Thermolesions are a dangerous complication of atrial fibrillation (AF) ablation. We aimed to assess the reasons for thermolesions and the effect of esophageal position on recurrences.

METHODS

The study included consecutive patients undergoing AF catheter ablation at Heart Center Leipzig between January and September 2014. We collected data of esophagus localization, temperature, endoscopy, and follow-up.

RESULTS

The study included 645 patients into analyses. A total of 626 (97.2%) received a temperature probe. Esophageal position was categorized: (A) behind left pulmonary veins, (B) left ostial, (C) in the middle of left atrium, (D) right ostial, and (E) behind right pulmonary veins. The most frequent esophageal position was B-C (n = 201, 32.1%), followed by B (n = 161, 25.7%), and C (n = 147, 23.5%). The temperature was highest in A-B positions (42.04°C) and in D-E positions (41.70°C). There was a significant correlation between the endoscopically detected esophageal lesions (EDEL) and the esophageal position (r² = -.115, P = .004) and the esophageal temperature (r² = .162, P = .000), but not with body mass index (BMI) (r² = -.016, P = .688). Additional substrate modification in the left atrium resulted in significantly higher esophageal temperatures (P < .001) and more frequent EDEL (P = .049). An EDEL was found in 15 patients (2.3% of all patients, 5.6% of patients receiving endoscopy). Of those, the median esophageal temperature was 41.8°C (interquartile range [IQR]: 41.2-42.4). Neither esophageal position nor temperature during ablation was associated with arrhythmia recurrences (both P > .400).

CONCLUSIONS

EDEL depended on the esophageal position and temperature, but not on BMI. Esophageal position and intraluminal temperature during ablation had no effect on recurrences.

Esophageal cooling for protection during left atrial ablation: a systematic review and meta-analysis

Purpose

Thermal damage to the esophagus is a risk from radiofrequency (RF) ablation of the left atrium for the treatment of atrial fibrillation (AF). The most extreme type of thermal injury results in atrio-esophageal fistula (AEF) and a correspondingly high mortality rate. Various strategies for reducing esophageal injury have been developed, including power reduction, esophageal deviation, and esophageal cooling. One method of esophageal cooling involves the direct instillation of cold water or saline into the esophagus during RF ablation. Although this method provides limited heat-extraction capacity, studies of it have suggested potential benefit. We sought to perform a meta-analysis of published studies evaluating the use of esophageal cooling via direct liquid instillation for the reduction of thermal injury during RF ablation.

Methods

We searched PubMed for studies that used esophageal cooling to protect the esophagus from thermal injury during RF ablation. We then performed a meta-analysis using a random effects model to calculate estimated effect size with 95% confidence intervals, with an outcome of esophageal lesions stratified by severity, as determined by post-procedure endoscopy.

Results

A total of 9 studies were identified and reviewed. After excluding preclinical and mathematical model studies, 3 were included in the meta-analysis, totaling 494 patients. Esophageal cooling showed a tendency to shift lesion severity downward, such that total lesions did not show a statistically significant change (OR 0.6, 95% CI 0.15 to 2.38). For high-grade lesions, a significant OR of 0.39 (95% CI 0.17 to 0.89) in favor of esophageal cooling was found, suggesting that esophageal cooling, even with a low-capacity thermal extraction technique, reduces the severity of lesions resulting from RF ablation.

Conclusions

Esophageal cooling reduces the severity of the lesions that may result from RF ablation, even when relatively low heat extraction methods are used, such as the direct instillation of small volumes of cold liquid. Further investigation of this approach is warranted, particularly with higher heat extraction capacity techniques.

Incidence of acute thermal esophageal injury after atrial fibrillation ablation guided by prespecified ablation index

INTRODUCTION

Ablation index (AI), a novel parameter defining energy application at single ablation lesions, calculated by integration of ablation time, energy, catheter stability, and contact force, has been documented to be associated with effective lesions and higher ablation efficacy. Using a prespecified target AI in addition to acute lesion efficacy may affect local collateral damage like esophageal thermal injury when used for guiding radiofrequency (RF) ablation at the posterior left atrial (LA) wall.

METHODS AND RESULTS

Consecutive patients undergoing first AF ablations using AI were included. Ablation energy was reduced to 25 W when ablating at posterior LA wall. Two different individually defined AI target values were used (300 and 350 for posterior wall ablation). Esophageal endoscopy (EE) was performed 1 to 3 days after ablation procedure to document and categorize endoscopically detected esophageal thermal lesion (EDEL). Two-hundred and eleven consecutive patients with postprocedural EE were included. Incidence of EDEL was 14% (29 of 211 patients; mild category 1 lesions in 22 of 29 patients (76%) and severe category 2 lesions (ulcers > 5 mm) in 7 of 29 patients (24% of EDEL group, 3% of total group). Ablation time at posterior LA wall (9.5 vs 9.0 minutes [P = .67]) was comparable in patients with and without EDEL.

CONCLUSION

LA posterior wall RF ablation adopting AI ≤350 was associated with 14% esophageal thermal injury including 3% of severe esophageal thermal ulcers. This incidence is comparable to historic control groups with non AI-guided AF ablation.