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.

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 .

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.

Esophageal temperature management during cryoballoon ablation for atrial fibrillation

INTRODUCTION

Esophageal thermal injury (ETI) is a well-recognized complication of atrial fibrillation (AF) ablation. Previous studies have demonstrated that direct esophageal cooling reduces ETI during radiofrequency AF ablation. The purpose of this study was to evaluate the use of an esophageal warming device to prevent ETI during cryoballoon ablation (CBA) for AF.

METHODS

This prospective, double-blinded study enrolled 42 patients with symptomatic AF undergoing CBA. Patients were randomized to the treatment group with esophageal warming (42°C) using recirculated water through a multilumen, silicone tube inserted into the esophagus (EnsoETM®; Attune Medical) (WRM) or the control group with a luminal single-electrode esophageal temperature monitoring probe (LET). Patients underwent upper endoscopy esophagogastroduodenoscopy (EGD) the following day. ETI was classified into four grades.

RESULTS

Baseline patient characteristics were similar between groups. Procedural characteristics including number of freezes, total freeze time, early freeze terminations, coldest balloon temperature, procedure duration, posterior wall ablation, and proton pump inhibitor and transesophageal echocardiogram use before procedure were not different between groups. The EGD was completed in 40/42 patients. There was significantly more ETI in the WRM group compared to the LET group (n = 8 [38%] vs. n = 1 [5%], p = 0.02). All ETI lesions were grade 1 (erythema) or 2 (superficial ulceration). Total freeze time in the left inferior pulmonary vein was predictive of ETI (360 vs. 300 s, p = 0.03).

CONCLUSION

Use of a luminal heat exchange tube for esophageal warming during CBA for AF was paradoxically associated with a higher risk of ETI.

The impact of mechanical oesophageal deviation on posterior wall pulmonary vein reconnection

AIMS

During atrial fibrillation ablation, oesophageal heating typically prompts reduction or termination of radiofrequency energy delivery. We previously demonstrated oesophageal temperature rises are associated with posterior left atrial pulmonary vein reconnection (PVR) during redo procedures. In this study, we assessed whether mechanical oesophageal deviation (MED) during an index procedure minimizes posterior wall PVRs during redo procedures.

METHODS AND RESULTS

Patients in whom we performed a first-ever procedure followed by a clinically driven redo procedure were divided based on both the use of MED for oesophageal protection and the ablation catheter employed (force or non-force sensing) in the first procedure. The PVR sites were compared between MED using a force-sensing catheter (MEDForce), or no MED with a non-force (ControlNoForce) or force (ControlForce) sensing catheter. Despite similar clinical characteristics, the MEDForce redo procedure rate (9.2%, 26/282 patients) was significantly less than the ControlNoForce (17.2%, 126/734 patients; P = 0.002) and ControlForce (17.5%, 20/114 patients; P = 0.024) groups. During the redo procedure, the posterior PVR rate with MEDForce (2%, 1/50 PV pairs) was significantly less than with either ControlNoForce (17.7%, 44/249 PV pairs; P = 0.004) or ControlForce (22.5%, 9/40 PV pairs; P = 0.003), or aggregate Controls (18.3%, 53/289 PV pairs; P = 0.006). However, the anterior PVR rate with MEDForce (8%, 4/50 PV pairs) was not significantly different than Controls (aggregate Controls-3.5%, 10/289 PV pairs, P = 0.136; ControlNoForce-2.4%, 6/249 PV pairs, P = 0.067; ControlForce-10%, 4/40 PV pairs, P = 1.0).

CONCLUSION

Oesophageal deviation improves the durability of the posterior wall ablation lesion set during AF ablation.

Is Incomplete Left Atrial Posterior Wall Isolation Associated With Recurrence of Atrial Fibrillation After Radiofrequency Catheter Ablation?

Background: Complete left atrial posterior wall isolation (LAPI) is not always achieved. We examined whether incomplete LAPI has an effect on outcomes after catheter ablation (CA). Methods and Results: This study enrolled 75 consecutive patients (mean [±SD] age 62.6±8.9 years, 74.7% male) who underwent LAPI by radiofrequency CA for persistent atrial fibrillation (AF). The median follow-up period was 541 days (interquartile range 338-840 days). Incomplete LAPI was defined as the presence of a successfully created roof or floor linear lesion. The rate of complete LAPI was 41.3% (31/75). Either a roof or floor linear lesion was created in 38 patients, whereas neither was created in 6. Multivariate Cox proportional hazards regression analysis revealed that female sex (hazard ratio [HR] 5.29; 95% confidence interval [CI] 1.81-16.8; P=0.002) and complete or incomplete LAPI (HR 0.17; 95% CI 0.03-0.79; P=0.027) were independent predictors of AF recurrence. Kaplan-Meier curves indicated that better outcome was associated with at least one rather than no successful linear lesion (86.5% vs. 50.0% at 1 year; P=0.043). There were no significant differences in outcomes between the complete LAPI and incomplete LAPI groups. Conclusions: Complete LAPI is unachievable in a significant percentage of patients with persistent AF. However, incomplete LAPI, as a result of aiming for complete LAPI, may have a benefit comparable to that of complete LAPI.

Long-standing Persistent Atrial Fibrillation Ablation: How do You Perform it?

Catheter ablation of long-standing persistent atrial fibrillation (LSPAF) presents unique challenges and the lack of large body of evidence surrounding management makes for disagreement and different approaches for treatment. Outlined is a case example that offers a comprehensive approach to ablation in patients with LSPAF that consists of risk factor management, an ablation strategy, a rigorous trigger protocol and follow-up rhythm monitoring. The case presented highlights management of this difficult population as best guided by current evidence and our experience. Ablation treatment and management strategies will continue to evolve with further randomized data and the advent of improved ablation technologies.

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.

Vagus nerve injury symptoms after catheter ablation for atrial fibrillation

BACKGROUND

Vagus nerve injury during catheter ablation for atrial fibrillation can significantly impact quality of life and result in lingering gastrointestinal symptoms. This study was designed to define risk factors of vagus nerve injury, symptoms, prevalence, and temporal resolution.

METHODS

A total of 100 patients undergoing radiofrequency catheter ablation (RFCA) were enrolled and consented to participate in the study. Patients completed a 22-item questionnaire that included questions specific to vagus nerve injury symptomatology during their baseline visit and at 1 and 3 months post-RFCA.

RESULTS

The average age of the population was 63 ± 10.6 years and 68% were male. A total of 100 patients completed their baseline questionnaire (90 patients completed the 1-month questionnaires and 85 patients completed the 3-month questionnaires). Symptoms rated as moderate were prevalent at baseline (trouble swallowing 13%, bloating 26%, feeling full 20%), and increased in all categories analyzed at 1 month and with the exception of trouble swallowing returned to the preablation percentages at 3 months (heartburn 22.4%, trouble swallowing 18.8%, bloating 16.5%, nausea 8.2%, vomiting 3.5%, constipation 18.8%, diarrhea 16.4%, feeling full 15.3%). Severe rated symptoms of trouble swallowing (2-5.5%), bloating (5-7.6%), and early satiety (5-9.8%) increased at 1 month and bloating and early satiety percentages remained approximately two times higher at 3 months (trouble swallowing 2.4%, bloating 8.2%, early satiety 7.1%).

CONCLUSION

The majority of symptoms were resolved by 3 months, although those patients who rate bloating and early satiety at a severe rating may have persistent symptoms.

The Extent of Mechanical Esophageal Deviation to Avoid Esophageal Heating During Catheter Ablation of Atrial Fibrillation

OBJECTIVES

This study sought to determine the extent of lateral esophageal displacement required during mechanical esophageal deviation (MED) and to eliminate luminal esophageal temperature elevation (LET_Elev) during pulmonary vein (PV) isolation.

BACKGROUND

MED is a conceptually attractive strategy of minimizing esophageal injury while allowing uninterrupted energy delivery along the posterior left atrium during PV isolation.

METHODS

MED was performed using a malleable metal stylet within a plastic tube placed within the esophagus. Barium was instilled to characterize the trailing esophageal edge. For each MED attempt, the MED_Effective, defined as the distance from the trailing esophageal edge-to-ablation line, was correlated to occurrences of LET_Elev.

RESULTS

In 114 consecutive patients/221 PV pairs undergoing MED (age 62.1 ± 11 years, 75% men, 62%/38% paroxysmal/persistent AF), esophageal stretching invariably occurred such that the esophageal edge trailed behind the plastic tube. MED_Effective distances of 0 mm to 10 mm, 10 mm to 15 mm, 15 mm to 20 mm or >20 mm were achieved in 60 (27.1%), 64 (29%), 48 (21.7%), and 49 (22.2%) attempts, respectively. Overall, LET elevation >38°C occurred in 81 of 221 (36.7%) PV pairs. The incidence of LET_Elev among the 4 groups was 73.3%, 35.9%, 25%, and 4.1%, respectively. MED_Effective distances were 9.1 ± 6.5 mm and 18 ± 7.6 mm in patients with and without LET_Elev, respectively (p < 0.0001). Three patients (2.6%) experienced clinically significant MED-related trauma, albeit only with a stiffer stylet.

CONCLUSIONS

Mechanical esophageal deviation >20 mm from the PV ablation line prevents significant esophageal heating during PV isolation, but this level of displacement was difficult to safely achieve with this off-the-shelf mechanical stylet approach.