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.

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.

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.

PV isolation guided by esophageal visualization with a tailored ablation strategy for the avoidance of esophageal thermal injury: a randomized trial.

PURPOSE: Radiofrequency ablation along the posterior wall of the left atrium may lead to atrioesophageal fistula due to esophageal thermal injury. The purpose of our study was to prospectively investigate whether ablation guided by soluble contrast esophageal visualization (SCEV) reduces injury during atrial fibrillation (AF) ablation. METHODS: Seventy-eight patients with paroxysmal AF undergoing circumferential pulmonary vein isolation (PVI) were randomized to a SCEV group (n = 39) and control group without visualization (n = 39). Cine imaging of the esophagus was performed during soluble contrast swallowing at the beginning of ablation, after adjacent ipsilateral PVI and at the end of the procedure. The ablation lesion set was modified to avoid radiofrequency delivery within the contrast esophagram boundaries. In the control group, a single final ingestion was performed at the end of the procedure. Esophageal injury was assessed by esophagogastroscopy within 24 h in all patients. RESULTS: In the control group, the ablation lesion crossed over the esophagus in 46.2% of patients, whereas in SCEV group, the ablation line violated the boundaries of the esophagus unavoidably in 15.4% of patients (confidence interval (CI); 1.61-13.98, p = 0.003). The incidence of esophageal injury was significantly lower in patients that underwent ablation with SCEV (5.1% vs. 20.5%, CI; 0.04-1.06, p = 0.042). Regardless of randomization group, patients who received ablation which overlapped the esophagus had a higher incidence of esophageal injury compared with those without overlap (37.5 vs. 1.9%, CI; 3.73-271.37, p = 0.000). CONCLUSIONS: Esophageal contrast visualization helps to reduce the potential for esophageal injury during paroxysmal AF ablation. This simple procedural adjunct has important implications to improve safety of paroxysmal AF ablation procedures globally.

Adjunctive percutaneous ablation targeting epicardial arrhythmogenic structures in patients of atrial fibrillation with recurrence after multiple procedures.

INTRODUCTION: Repeat ablation strategy for atrial fibrillation (AF) recurrence after multiple ablation procedures is known to be challenging. This study evaluated the insights of adjunctive ablation for epicardial arrhythmogenic substrates in those patients via a percutaneous epicardial approach. METHODS AND RESULTS: Thirty-five consecutive patients with AF/atrial tachycardia (AT) recurrence, who had two or more prior ablation procedures, were enrolled from September 2016 to December 2018. In addition to a standard endocardial approach, epicardial mapping and ablation were performed via a percutaneous subxiphoid access in the electrophysiology lab. Adjunctive epicardial ablations for left lateral ridge (LLR) were performed in 31 of 35 patients (88.6%) for efficient transmural lesions with pacing capture loss. Marshall Bundle (MB) potentials were documented on epicardial LLR in three patients and abolished by direct epicardial ablation. Bachmann's bundle (BB) was ablated as an epicardial conduction gap in four patients with a refractory anterior wall line. Two epicardial AT/AF triggers were detected followed by successful termination with epicardial ablation. No periprocedural complications occurred. About 23 of 35 patients (65.7%) remained free from AF/AT after 23.2 ± 9 months of the procedure. CONCLUSIONS: Patients with multiple failed prior AF procedures refractory to antiarrhythmic therapy might warrant a percutaneous epicardial mapping and ablation strategy, with adjunctive therapy for targeting LLR/MB, BB, and underlying epicardial triggers in addition to a standard endocardial approach.

Metabolic benefits of rivaroxaban in non-valvular atrial fibrillation patients after radiofrequency catheter ablation.

BACKGROUND AND OBJECTIVE: Rivaroxaban is a new oral anticoagulant for stroke prevention in patients with non-valvular atrial fibrillation (NVAF), which has less drug-food interaction than warfarin. We conducted this prospective randomized study to evaluate the metabolic benefits as well as the safety and efficacy with rivaroxaban versus warfarin in patients with NVAF following radiofrequency catheter ablation (RFCA). METHODS: From April to July 2014, 60 patients with NVAF undergoing RFCA were prospectively enrolled in our study. Following RFCA, all patients were randomly assigned to receive rivaroxaban (Group R, n=30) or warfarin (Group W, n=30). Metabolic indices including serum total protein, albumin, globulin, and high-density lipoprotein (HDL) as well as bleeding, stroke, and systemic thromboembolism events were evaluated and compared during follow-up after 15, 30, 60, and 90 d of RFCA procedure. RESULTS: Serum total protein, albumin, globulin, and HDL levels were all significantly elevated at each follow-up stage in Group R when compared to the baseline (P<0.05 respectively). In Group W, the metabolic indices decreased at first and then had an increasing trend. There were no deaths or thromboembolic complications in each group. The prevalence of total bleeding complications was similar between Group R and Group W (11/30, 36.7% vs. 10/30, 33.3%, P=0.79). CONCLUSIONS: Patients with NVAF receiving rivaroxaban after RFCA procedures appear to benefit from a metabolic perspective compared with warfarin, providing practical clinical reference for the choice of the anticoagulant. Rivaroxaban seems to be as safe and effective in preventing thromboembolic events as warfarin for these patients.

Impact of Anatomically Guided Ganglionated Plexus Ablation on Electrical Firing from Isolated Pulmonary Veins.

BACKGROUND: The mechanisms underlying atrial fibrillation (AF) initiation and pulmonary vein isolation (PVI) effectiveness remain unclear. Ganglionated plexus (GPs) have been implicated in AF initiation and maintenance. In this study, we evaluated the impact of GP ablation in patients with pulmonary vein (PV) firing after PVI. METHODS: Patients with drug-refractory paroxysmal AF undergoing radiofrequency catheter ablation therapy with PVI were screened. Among 840 cases over a 3.75-year period, 12 cases were identified with persistent PV firing (left = 4 and right = 8) after PVI was achieved and left atrial sinus rhythm restored. Adjacent GP ablation was performed anatomically and followed if necessary by additional PV ablation. RESULTS: In eight patients, PV firing was terminated during GP ablation outside of the circumferential ablation line. In one patient, additional PV ablation resulted in cessation of PV firing and in the remaining three patients, firing could not be terminated by GP ablation or additional PVI. CONCLUSION: GP ablation outside of wide antral circumferential line frequently results in the cessation of rapid firing from electrically isolated PVs. These observations suggest that interactions between left atrium and PV beyond electrical conduction warrant consideration in AF mechanisms.

Non-pulmonary vein foci induced before and after pulmonary vein isolation in patients undergoing ablation therapy for paroxysmal atrial fibrillation: incidence and clinical outcome.

OBJECTIVE: To evaluate the incidence and clinical outcome of adenosine triphosphate (ATP) plus isoproterenol (ISP)-induced non-pulmonary vein (PV) foci before and after circumferential PV isolation (CPVI) during index ablation in patients with paroxysmal atrial fibrillation (PAF). METHODS: In 80 consecutive patients undergoing catheter ablation for drug-refractory, symptomatic PAF at our hospital from April 2010 to January 2011, atrial fibrillation (AF) was provoked with ATP (20 mg) and ISP (20 µg/min) administration before and after CPVI. The spontaneous initiation of AF was mapped and recorded. RESULTS: Before ablation, AF mostly originating from PVs (PV vs. non-PV, 36/70 vs. 3/70; P<0.01) was induced in 39 patients with sinus rhythm. CPVI significantly suppressed AF inducibility; however, more non-PV foci were provoked (post-CPVI vs. pre-CPVI, 13/76 vs. 3/70; P=0.016). Patients with pre- and post-CPVI induced AF (n=49) were divided according to non-PV foci being induced (group N, n=17) or not (group P, n=32). After mean (19.2±8.2) months follow-up, 88.2% (15/17) and 65.6% (21/32) of patients in groups N and P, respectively, were free from AF recurrence (P=0.088). CONCLUSIONS: ATP+ISP administration effectively provokes non-PV foci, especially after CPVI in PAF patients. Although in this study difference did not achieve statistical significance, supplementary ablation targeting non-PV foci might benefit clinical outcome.

Incidence of pulmonary vein conduction recovery in patients without clinical recurrence after ablation of paroxysmal atrial fibrillation: mechanistic implications.

BACKGROUND: Pulmonary vein (PV) isolation has become the mainstay acute procedural end point for paroxysmal atrial fibrillation (AF) ablation. OBJECTIVE: To examine the incidence of conduction recovery in the PVs in patients without clinical recurrence of AF after paroxysmal AF ablation. METHODS: From August 2008 to March 2011, 392 patients with drug-refractory PAF underwent catheter ablation in our center, a wide area circumferential ablation approach guided with a circular mapping catheter was performed with the intended endpoint of entrance block in all PVs. 276 (70.4%) of them were free from recurrence at one year follow-up, and 32 of them were enrolled to assess the incidence of PV reconnection. Forty-three patients with clinical recurrence after ablation were analyzed for comparison. The regions of gap were mapped and characterized in all of the reconnected PVs. RESULTS: Among patients without recurrence, recovery of PV conduction was observed in 29 of 32 (90.6%) patients: 10/32 (31.2%) reconnection in 4 veins, 7/32 (21.9%) in 3 veins, 10/32 (31.2%) in 2 veins, and 2/32 (6.2%) in 1 vein. No anatomic propensity was seen because reconnection was evenly distributed throughout all veins (left superior pulmonary vein 21, left inferior pulmonary vein 20, right superior pulmonary vein 19, and right inferior pulmonary vein 23). When compared to patients with recurrence, no significant differences were seen in the proportion of patients with reconnection (P = 1.0) or in left atrium-PV intervals (73.4 ± 43.3 ms vs 61.9 ± 31.8 ms; P > .05). CONCLUSION: A high incidence of PV reconnection was similarly observed in patients with and without recurrence of AF, suggesting that sustained PV isolation may not be required for freedom from clinical recurrence of AF.

Marked suppression of pulmonary vein firing after circumferential pulmonary vein isolation in patients with paroxysmal atrial fibrillation: is pulmonary vein firing an epiphenomenon?

INTRODUCTION: Rapid firing in pulmonary veins (PVs) is a leading cause of paroxysmal atrial fibrillation. We hypothesized that PV firing (PV-F) should continue after circumferential PV isolation (CPVI) because the PV tissue responsible for PV-F remains intact. METHODS AND RESULTS: In Group-1 (n = 92), isoproterenol (ISP) and adenosine triphosphate (ATP) were co-administered to provoke PV-F before and after CPVI. The site of rapid focal discharge that initiated atrial fibrillation (AF) defined PV-F versus non-PV-F. Additional 17 patients with PV-F induced by ISP+ATP before CPVI were enrolled into Group-2 and various pacing maneuvers were used in conjunction to ISP+ATP to provoke PV-F after CPVI. In Group-1, AF was induced in 47/81 (58.0%) and 16/88 (18.2%) patients before and after CPVI, respectively (P < 0.01). Before CPVI, 43/47 (91.5%) of the rapid firing originated from PV. After successful CPVI, 88/92 patients were in sinus rhythm and non-PV-F was induced in 14/88 patients. PV-F was induced in 2/88 patients, which was eliminated by ganglionated plexus ablation outside the CPVI line. In Group-2, various pacing maneuvers with ISP+ATP only induced PV-F in 1/17 patients after CPVI. CONCLUSION: Marked suppression of PV-F after CPVI strongly suggests that the real source of PV-F is located in the atrium. PV-F may be an epiphenomenon.

Regional ganglionated plexus ablation eliminated rapid firing in an electrically isolated pulmonary vein.

Atrial fibrillation (AF) was initiated by rapid firing from left superior pulmonary vein (PV) by administration of isoproterenol (ISP) and adenosine triphosphate (ATP) before ablation. After successful isolation of all PVs, ISP and ATP were administered again. PVs were still isolated but an episode of rapid firing was observed inside the left PV isolation line during sinus rhythm. Radiofrequency energy was then delivered to the areas of superior left ganglionated plexus (GP) and inferior left GP. Then, PV firing could no longer be initiated. It suggests additional GP ablation may have additional benefit to circumferential PV isolation, to reduce the incidence of AF recurrence.

Dissociated pulmonary vein rhythm may predict the acute pulmonary vein reconnection post-isolation in patients with paroxysmal atrial fibrillation.

AIMS: Dissociated pulmonary vein rhythm (PVD) has been taken as a signal of PV isolation, but has been questioned recently; we assessed the relationship between PVD and acute PV reconnection after PV isolation in this study. METHODS AND RESULTS: Eighty-five consecutive patients (52 males; mean age 59±11 years) were referred for catheter ablation of drug-refractory paroxysmal AF. Following PV isolation, the presence and cycle length of PVD were recorded. Pulmonary veins were classified into veins with PVD (Group 1) and veins without PVD (Group 2). Adenosine triphosphate (ATP) was then injected during isoproterenol infusion to reveal dormant conduction gap(s), and PVs were further remapped at 30 min post-isolation. Totally, PVD was observed in 68% (58 of 85) of patients and 34.7% (112 of 323) of PVs. Seventy-nine (24.5%) PVs were found acutely reconnected, including 48 veins revealed by ATP induction [ATP(+)PV] and 64 veins by reassessment after 30 min post-isolation [Time(+)PV]. Time(+)PVs were observed more frequently in Group 1 than those in Group 2 (31.3 vs. 13.7%, P<0.01), but no significant difference was found in the occurrence of ATP(+)PVs between Group 1 and Group 2 (17.9 vs. 13.3%, P=0.27). The sequences of the PVD and the acutely reconnected PV potential were similar in 87.5% of veins. After PV re-isolation, 70% (28 of 40) of previously documented PVD disappeared. CONCLUSION: The occurrence of PVD after PV isolation was closely related to the acute PV reconnection after 30 min post-isolation.

ATP revealed extra pulmonary vein source of atrial fibrillation after circumferential pulmonary vein isolation.

Noninducibility of atrial fibrillation (AF) by additional electrograms-guided ablation may benefit the clinical outcome. This report illustrates the effect of adenosine triphosphate (ATP) injection on AF inducibility after pulmonary vein (PV) isolation. AF was triggered twice by ATP without PV reconnection. Meanwhile, complex fractionated atrial electrograms (CFAEs) were observed, and ablation targets on these sites appeared to be essential to the AF elimination. It suggests that CFAEs may contribute to the initiation of some AF. ATP may be useful to induce AF after proven PV isolation, and further ablation might be necessary to ensure efficacy after circumferential PV isolation.

Early detection of pulmonary vein reconnection after isolation in patients with paroxysmal atrial fibrillation: a comparison of ATP-induction and reassessment at 30 minutes postisolation.

INTRODUCTION: Catheter ablation for paroxysmal AF (PAF) is limited by an unacceptable recurrence rate, mainly due to pulmonary vein (PV) reconnection. Strategies to minimize reconnection include adenosine infusion and also a waiting period of 30 minutes after PV isolation. The aim of the present study was to assess whether these two strategies revealed the same conduction gap. METHODS AND RESULTS: In total, 88 consecutive patients (54 males, mean age of 60 years) with drug refractory PAF underwent circumferential PV isolation (CPVI). After isolation of ipsilateral PVs, with entry and exit block checked using a circular mapping catheter, 20 mg ATP was injected during isoproterenol infusion to reveal dormant conduction gap(s). Unless the reconnection revealed by ATP persisted, PVs were further remapped with the circular mapping catheter at 30 minutes postisolation. Totally, PV reconnection was observed in 56 (64%) patients. 24.3% veins (80/329) were found reconnected. Reassessment at 30 minutes postablation was more efficient as compared to ATP induction (19.8% vs 14.6% for ATP). The agreement between these 2 methods is moderate (kappa value = 0.50). In veins that transiently reconnected after ATP administration and later observed at 30 minutes postablation, 94% (17 of 19) of them were found being reconnected with the same gap. CONCLUSION: Acute PV reconnection is common, occurring in 64% of patients, as detected by adenosine infusion and waiting time. Each shows a unique quality as compared to one another. The combined use of these 2 methods may reduce the AF recurrence rate after CPVI.