Patients Undergoing Catheter Ablation For Atrial Fibrillation Research Articles

Accelerated pacing reduces left heart filling pressures: a novel therapy for heart failure with preserved ejection fraction?

Abstract Background The recent MyPACE trial demonstrated significant improvement of quality-of-life, physical activity, and atrial fibrillation (AF) burden with accelerated pacing as compared to the standard 60bpm back-up rate setting in patients with heart failure with preserved ejection fraction (HFpEF) and indication for pacemaker therapy. We hypothesized that a potential working mechanism underlying these improved outcomes lies in the reduction of left heart filling pressures during accelerated pacing, reducing congestion and atrial stretch. Aim To assess the acute effects of accelerated atrial pacing on left heart filling pressures in consecutive AF patients undergoing catheter ablation. Methods Fifty AF patients undergoing catheter ablation were prospectively enrolled for accelerated atrial pacing. As illustrated in Figure 1, pacing was performed proximally in coronary sinus (CS). Pacing rate was increased incrementally from resting heart rate by 10-bpm increments up to Wenckebach rhythm, with 30-sec intervals of pacing on and off for hemodynamic stabilization. Left atrial pressure (LAP) was continuously monitored via a fluid-filled transseptal sheath (SL0 sheath, Abbott). Acute pacing-induced changes in mean LAP and PR-interval were evaluated at each pacing rate and compared between resting heart rate, the patient-specific optimal heart rate (i.e., the rate resulting in the lowest mean LAP), and the maximum pacing rate. Results Atrial pacing acutely decreased mean LAP from 14.8[9.8; 18.4] to 12.8[8.5; 15.8]mmHg (median[IQR], p<0.001) as heart rate increased from 51[47; 61] to 90[70; 100]bpm (p<0.001) (Figure 2, resting versus optimal category). Among the 50 patients included, only 4 did not exhibit a decrease in LAP. Further increasing pacing rate to a maximum of 130[100; 140]bpm resulted in an acute LAP increase to 16.2[12.7; 19.9]mmHg (p<0.001) to values above resting mean LAP. Accelerated pacing induced negative AV dromotropy, i.e., lengthening of the PR-interval from 169[150; 185] to 186[164; 209]ms (p=0.003) and 270[217; 310]ms (p<0.001). Conclusion Our study demonstrated that moderately accelerated atrial pacing reduced mean LAP in AF patients undergoing catheter ablation. While our primary focus was on acute response in AF patients, the reduction in mean LAP during moderate pacing rates may suggest a promising therapeutic approach for managing HFpEF patients. However, caution is warranted as pacing rates beyond the optimal range led to a marked increase in LAP. Additionally, increasing pacing rates were observed to induce varying degrees of AV-node dromotropy, which potentially modulates therapy response.Fig 1. Overview of clinical protocolFig 2. Response to accelerated pacing

Clinical determinants of blood biomarkers of atrial cardiomyopathy: results from the ISOLATION AF ablation cohort study

Abstract Background In patients with atrial fibrillation (AF), significant advances have been made in identifying biomarkers representing diverse pathophysiological pathways, such as inflammation, myocyte injury, collagen deposition, and fatty-fibrotic infiltration. Data on clinical determinants of biomarkers in patients with AF, however, are lacking. Objective Our primary aim was to explore the relationships between clinical determinants and biomarker levels in AF patients scheduled for catheter ablation. Methods A cross-sectional analysis was conducted in AF patients undergoing catheter ablation included in the prospective multicenter ISOLATION study between July 2020 and May 2022. Clinical characteristics, routine tests and blood samples were collected before ablation. Blood samples were analyzed for known and novel cardiovascular biomarkers, including Bone morphogenetic protein 10 (BMP10), Angiopoietin-2 (Ang-2), Fibroblast growth factor 23 (FGF-23), Dickkopf-related protein 3 (DKK-3), Endocan (ESM-1), Insulin-like growth factor-binding protein 7 (IGFBP-7), B-type natriuretic peptides (proBNP, NTproBNP), High sensitive Troponin-T (hsTnT)< Growth differentiation factor 15 (GDF-15), interleukin 6 (IL-6), Fatty acid binding protein 3 (FABP3), Cancer antigen-125 (Ca-125) (Table 1). For each biomarker we trained a lasso regression model to identify the most important clinical determinants out of all the 60 available determinants (including anthropometry, ECG, comorbidities). The strongest associations are summarized in figure 1. Results Blood samples of 508 patients were analyzed. The mean age was 63 ±9 years, and 31.1% were female. 354 patients (69.7%) had paroxysmal AF and 154 patients (30.3%) had persistent AF. Heart failure was reported in 77 patients (15.2%). 355 (72.3%) patients were in sinus rhythm during sample collection. The following clinical determinants of biomarker levels were frequently identified as important: rhythm during blood phlebotomy, age, heart failure, decreased kidney function and female sex (Figure 1). Most notably, rhythm at the time of sampling was strongly associated with various biomarker levels. Female sex was positively associated with BMP10 and FGF23 (atrial fibrosis), but negatively associated with hsTNT (cardiac injury). Conclusion In patients with AF scheduled for catheter ablation, we identified several clinical determinants of biomarker levels with potential implications for disease mechanisms. In women, pro-fibrotic biomarkers were frequently higher, while male patients more often showed signs of myocardial injury. Importantly, rhythm during blood draw is a very strong determinant of many biomarkers and should be taken into account in future biomarker studies.Figure 1.Table 1.

Characterization and clinical significance of hemolysis after pulsed-field ablation for atrial fibrillation: insights from a multicentric analysis

Abstract Background Pulsed-field ablation is a novel non-thermal ablation modality which is being increasingly used in clinical practice for the treatment of atrial fibrillation (AF). While the susceptibility of erythrocytes to electroporation is well-established, the effect of cardiac PFA technologies on erythrocyte destruction has not been described so far. Purpose The aim of this study was to investigate whether PFA induces clinically significant hemolysis. Methods We included 187 patients undergoing AF catheter ablation with either PFA (n=145) or RFA (n=42) at four high-volume centers. PFA was performed using a pentaspline catheter (biphasic, bipolar pulses of 2kV) and RFA with a 3.5 mm irrigated-tip catheter (40-60 W). The lesion set comprised pulmonary vein isolation (PVI) for paroxysmal AF and PVI ± additional lesions/lines for persistent AF. Established biomarkers of hemolysis, anemia and renal function were analyzed in blood samples obtained at baseline (T1), at the end of ablation (T2) and 24 hours after the procedure (T3). Results Baseline characteristics were well-balanced between groups (65.5 ± 9.6 years, 72.7% male, p>0.05). The ablation procedures comprised a mean of 61.4 ± 27.2 deliveries (PFA group) and a mean RF duration of 31.0 ± 16.3 min (RFA group). Atrial ablation in addition to PVI was performed in 55.2% vs. 61.9% patients, respectively (p=0.469). The direct hemolysis marker free plasma hemoglobin was significantly higher with PFA (592.8 ± 330.6 mg/dl) than with RFA (186.6 ± 215.8 mg/dl, p<0.001) at the end of ablation. A strong correlation was found between free plasma hemoglobin and PFA deliveries (Pearson r=0.615, p<0.001). PFA was further associated with a 2.2-fold increase in bilirubin (21.3 ± 11.3 vs. 9.6 ± 4.7 µmol/l), a 2.4-fold decrease in haptoglobin (0.5 ± 0.4 vs. 1.2 ± 0.4 g/l) and a 1.8-fold increase in LDH (352.7 ± 115.7 vs. 192.2 ± 51.6 U/l, T3 vs. T1, all p<0.001). There were no significant changes in bilirubin and haptoglobin in the RFA group (p>0.05). A slight decrease in red blood cells, hemoglobin and hematocrit was detected after both PFA and RFA (Abstract Figure), with no significant differences between groups (all p>0.05). While mean creatinine levels and glomerular filtration rates did not significantly change after ablation in either group, acute kidney injury occurred in 4/124 (3.2%) with PFA vs. 0/32 (0%) with RFA (p=0.303). Conclusion Intravascular hemolysis is a frequent finding after PFA for AF and increases with the number of PFA deliveries. While PFA was not associated with clinically significant anemia, the incidence of acute kidney injury in the present study warrants future large-scale investigations assessing the biological impact and nephrotoxicity of PFA-induced hemolysis.Abstract Figure

Safety and efficacy of anticoagulation therapy post atrial fibrillation ablation

Abstract Funding Acknowledgements None. Background Thromboembolic complications can be life-threatening during atrial fibrillation (AF) catheter ablation. The aim of our single center, retrospective study was to evaluate the safety and efficacy of continuous treatment using direct oral anticoagulants (DOACs) as an alternative to uninterrupted acenocoumarol for periprocedural anticoagulation. Purpose To record the safety and efficacy of the oral anticoagulants post atrial fibrillation ablation. Methods We studied 1999 patients undergoing AF catheter ablation between June 2013 and December 2021 in our center. All patients were assigned to take acenocoumarol (group 1, 194 patients) or DOACs (group 2, 1805 patients) for ≥2 months before the procedure. We compared thromboembolic and bleeding complications between the 2 groups. Results Our analysis showed no significant difference in major and minor complications between the 2 patient groups with the exception of the occurrence of groin hematoma with a clear superiority of DOACs (2.06%-0.5%, p<0.05). Specifically, 4 of 194 patients (2.06%) using uninterrupted acenocoumarol had a major complication (3 patients [1.55%] had transient ischemic attack resolved 8 hours later and 1 [0.52%] had pericardial tamponade, and 7 patients (3.61%) had minor complications (4 [2.06%] groin hematoma and 3 [1.55%] mild pericardial efussion). In group 2, 14 of 1805 patients (0.78%) had a major complication (11 patients had transient ischemic attack (0.61%) and 3 patients (0.17%) had pericardial tamponade). In the same group, 31 patients (1.72%) had a minor complication (3 patients [0.17%] presented with pseudoaneurysm or femoral arteriovenous fistula between the femoral artery and femoral vein, 19 [1.05%] with pericardial effusion <1 cm, and 9 [0.5%] groin hematoma). Conclusions DOACs and acenocoumarol have similar safety and effectiveness regarding thromboembolic complications prevention without increasing bleeding complications with the exception of the occurrence of groin hematoma with a clear superiority of DOACs.

Epicardial Atrial Fat at Cardiac Magnetic Resonance Imaging and AF Recurrence after Transcatheter Ablation.

The relationship between epicardial adipose tissue (EAT) and atrial fibrillation (AF) has gained interest in recent years. The previous literature on the topic presents great heterogeneity, focusing especially on computed tomography imaging. The aim of the present study is to determine whether an increased volume of left atrial (LA) EAT evaluated at routine pre-procedural cardiac magnetic resonance imaging (MRI) relates to AF recurrences after catheter ablation. A total of 50 patients undergoing AF cryoballoon ablation and pre-procedural cardiac MRI allowing quantification of LA EAT were enrolled. In one patient, the segmentation of LA EAT could not be achieved. After a median follow-up of 16.0 months, AF recurrences occurred in 17 patients (34%). The absolute volume of EAT was not different in patients with and without AF recurrences (10.35 mL vs. 10.29 mL; p-value = 0.963), whereas the volume of EAT indexed on the LA volume (EATi) was lower, albeit non-statistically significant, in patients free from arrhythmias (12.77% vs. 14.06%; p-value = 0.467). The receiver operating characteristic curve testing the ability of LA EATi to predict AF recurrence after catheter ablation showed sub-optimal performance (AUC: 0.588). The finest identified cut-off of LA EATi was 10.65%, achieving a sensitivity of 0.5, a specificity of 0.82, a positive predictive value of 0.59 and a negative predictive value of 0.76. Patients with values of LA EATi lower than 10.65% showed greater survival, free from arrhythmias, than patients with values above this cut-off (84% vs. 48%; p-value = 0.04). In conclusion, EAT volume indexed on the LA volume evaluated at cardiac MRI emerges as a possible independent predictor of arrhythmia recurrence after AF cryoballoon ablation. Nevertheless, prospective studies are needed to confirm this finding and eventually sustain routine EAT evaluation in the management of patients undergoing AF catheter ablation.

Efficacy of Computed Tomography-Based Evaluation of Myocardial Extracellular Volume Combined With Red Flags for Early Screening of Concealed Cardiac Amyloidosis in Patients With Atrial Fibrillation.

The prevalence of transthyretin amyloid cardiomyopathy (ATTR-CM) in atrial fibrillation (AF) patients remains unclear. We explored the efficacy of computed tomography-based myocardial extracellular volume (CT-ECV) combined with red flags for the early screening of concealed ATTR-CM in AF patients undergoing catheter ablation.Methods and Results: Patients referred for AF ablation at Oita University Hospital were prescreened using the red-flag signs defined by echocardiographic or electrocardiographic findings, medical history, symptoms, and blood biochemical findings. Myocardial CT-ECV was quantified in red flag-positive patients using routine pre-AF ablation planning cardiac CT with the addition of delayed-phase cardiac CT scans. Patients with high (>35%) ECV were evaluated using technetium pyrophosphate (99 mTc-PYP) scintigraphy. A cardiac biopsy was performed during the planned AF ablation procedure if 99 mTc-PYP scintigraphy was positive. Between June 2022 and June 2023, 342 patients were referred for AF ablation. Sixty-seven (19.6%) patients had at least one of the red-flag signs. Myocardial CT-ECV was evaluated in 57 patients because of contraindications to contrast media, revealing that 16 patients had high CT-ECV. Of these, 6 patients showed a positive 99 mTc-PYP study, and 6 patients were subsequently diagnosed with wild-type ATTR-CM via cardiac biopsy and genetic testing. CT-ECV combined with red flags could contribute to the systematic early screening of concealed ATTR-CM in AF patients undergoing catheter ablation.

Distribution of triggers in the left atrial posterior wall in AF patients undergoing catheter ablation

Abstract Introduction Having a common embryologic origin with the pulmonary veins (PVs), left atrial posterior wall (LAPW) is considered to be a source of non-PV triggers that facilitate maintenance of atrial fibrillation (AF). However, the benefits of electrical isolation of the posterior wall (PWI) is still debated with contradictory data originating from different ablation approaches. Purpose We report the distribution of triggers in the LAPW area in AF patients undergoing repeat ablation. Methods Consecutive AF patients undergoing catheter ablation between 2015 and 2022 were included in this analysis. PVs were isolated first. Next, high-dose isoproterenol challenge (up to 30µg/min) was used to disclose triggers in the PW by moving the circular mapping catheter along the PW down to the level of coronary sinus, which were targeted using additional RF energy. We defined lower part of LAPW as the area between the line joining the inferior borders of the inferior PV-encircling lesions and the coronary sinus. The endpoint was to achieve electrical isolation, as documented by absence of any electrical activity in the PW. Results Of the 10,963 AF ablations performed during the specified time period, 6249 (57%) had triggers mapped and ablated in the LAPW area. Triggers were seen to be originating from the part of the PW between the PVs in 4124 (66%) and from the lower part of the PW in 2125 (34%) patients. Of these, 1624 (26%) patients had focal triggers detected in both the area between the PVs and the lower PW. All triggers from in between PVs were targeted for ablation, whereas lower PW sites were ablated in 1296 (61%) and not targeted for ablation the remaining 829 (39%). Figure 1 demonstrates the triggers arising from lower PW. At 1 year, amongst patients with lower PW triggers, 1049/1296 (81%) vs 326/829 (39.3%) (p<0.001) were arrhythmia-free. Conclusion Ectopic triggers in the LAPW were documented to be arising from the lower part of the PW in approximately 1/3rd of cases and ablation of those sites resulted in significantly higher success rate.

Safety and Efficacy of Uninterrupted Oral Anticoagulation in Patients Undergoing Catheter Ablation for Atrial Fibrillation with Different Techniques.

The safety and efficacy of an uninterrupted direct anticoagulation (DOAC) strategy during catheter ablation (CA) for atrial fibrillation (AF) has not been fully investigated with different ablation techniques. We evaluated consecutive AF patients undergoing catheter ablation with three different techniques. All patients were managed with an uninterrupted DOAC strategy. The primary endpoint was the rate of periprocedural thromboembolic and bleeding events. The secondary endpoints of the study were the rate of MACE and bleeding events at one-year follow-up. In total, 162 patients were enrolled. Overall, 53 were female and the median age was 60 [55.5-69.5] years. The median CHA2DS2-VASc and HAS-BLED scores were 2 [1-4] and 2 [1-2], respectively. In total, 16 patients had a past stroke or TIA while 11 had a predisposition or a history of bleeding. The CA procedure was performed with different techniques: RF 43%, cryoballoon 37%, or laser-balloon 20%. Overall, 35.8% were on rivaroxaban, 20.4% were on edoxaban, 6.8% were on apixaban, and 3.7% were on dabigatran. All other patients were all naïve to DOACs; the first anticoagulant dose was given before the ablation procedure. As for periprocedural complications, we found three groin hematomas not requiring interventions, one ischemic stroke, and one systemic air embolism (the last two likely due to several catheter changes through the transeptal sheath). Five patients reached the secondary endpoints: one patient for a myocardial infarction while four patients experienced minor bleeding during 1-year follow-up. Our results corroborate the safety and the efficacy of uninterrupted DOAC strategy in patients undergoing CA for AF, regardless of the ablation technique.

A hub-and-spoke model: the role of satellite cardiac electrophysiology laboratory units in mitigating the waiting list pressures for catheter ablation for atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Since setting up the cardiac electrophysiology (EP) service at our tertiary centre (UH) in 2010, there has been a significant increase in referrals for EP procedures especially catheter ablation for atrial fibrillation (AF). UH serves a catchment area of above 1 million people and the increasing demand coupled with limited resources in a publicly funded health system has led to a huge supply-demand mismatch in our AF ablation waiting list. This mismatch was compounded by the COVID-19 pandemic. Aim To share our experience of how we attempted to mitigate the waiting list pressures on our AF ablation procedures before and during the pandemic by utilising satellite cardiac EP laboratory units. Methods Firstly, we made cryoballoon pulmonary vein isolation (PVI) the initial ablation strategy for all of our paroxysmal and persistent AF patients undergoing catheter ablation (due to shorter procedure times and standardised workflow). All cryoballoon PVI cases were performed under local anaesthesia. In 2016, we transitioned from overnight-stay to same-day AF ablation and demonstrated its safety and cost-effectiveness. Finally, we increased our EP laboratory capacity by developing a hub-and-spoke model in collaboration with 2 secondary care centres regionally (WH & StX). From May 2019, cryoballoon PVI cases were performed at 3 sites: UH (hub) and 2 satellite units (WH & StX). During the pandemic, 3 national lockdowns were declared (23/3/20, 5/11/20, 6/1/21) and national healthcare services were restructured. Urgent inpatient cardiac EP cases were still performed at UH but elective EP procedures across all three sites (UH, WH & StX) were cancelled during the first national lockdown. One of the steps taken to mitigate the impact of the pandemic on our increasing AF ablation waiting list was to collaborate with the private sector (MH) which functioned as a ‘clean’ site for elective EP procedures. Cryoballoon PVI cases resumed within 2 months of the first national lockdown. From September 2020, all 3 sites [UH and its two satellite units (WH & MH)] were performing cryoballoon PVI. Data from every EP case performed in all centres was entered into an electronic database. Data was extracted from the 1st January 2019 (pre-pandemic) to the 31st December 2021 (post-pandemic). UH was labeled as ‘tertiary unit’ while WH, StX and MH were pooled together and labeled as ‘satellite units’. Results The implementation of three national lockdowns led to a transient decrease in the number of electrophysiology procedures (Figure 1). However, the ‘clean’ patient pathway that we rapidly established at our satellite unit (MH) facilitated the sustained delivery of our cardiac electrophysiology service throughout the pandemic from 2020 to 2021. There were no deaths or differences in complication rates between the 2 units (Table 1). Conclusion Our hub-and-spoke model is a safe and practical system in tackling the AF ablation waiting list even throughout the pandemic.

AB-452663-3 DISTRIBUTION OF TRIGGERS IN THE LEFT ATRIAL POSTERIOR WALL IN AF PATIENTS UNDERGOING CATHETER ABLATION

Having a common embryologic origin with the pulmonary veins (PVs), left atrial posterior wall (LAPW) is considered to be a source of non-PV triggers that facilitate maintenance of atrial fibrillation (AF). However, the benefits of electrical isolation of the posterior wall (PWI) is still debated with contradictory data originating from different ablation approaches. . We report the distribution of triggers in the LAPW area in AF patients undergoing repeat ablation. Consecutive AF patients undergoing catheter ablation between 2015 and 2022 were included in this analysis. PVs were isolated first. Next, high-dose isoproterenol challenge (up to 30μg/min) was used to disclose triggers in the PW by moving the circular mapping catheter along the PW down to the level of coronary sinus, which were targeted using additional RF energy. We defined lower part of LAPW as the area between the line joining the inferior borders of the inferior PV-encircling lesions and the coronary sinus. The endpoint was to achieve electrical isolation, as documented by absence of any electrical activity in the PW. Of the 10,390 AF ablations performed during the specified time period, 5843 (56.2%) had triggers mapped and ablated in the LAPW area. Triggers were seen to be originating from the part of the PW between the PVs in 3809 (65.2%), from the lower part of the PW in 2028 (34.7%) and focal triggers from all over the PW including the lower part in 1519 (26%) cases. All triggers were targeted for ablation. Figure 1 demonstrates the triggers arising from lower PW. Ectopic triggers in the LAPW were documented to be arising from the lower part of the PW in a large number of cases. Thus, operators should consider extending the ablation to include the lower LAPW area to maximize the benefits of PWI.

Impact of Colchicine Monotherapy on the Risk of Acute Pericarditis Following Atrial Fibrillation Ablation

BackgroundAcute pericarditis is a known complication of ablation procedures for atrial fibrillation (AF). ObjectivesThis study aimed to evaluate the benefits of colchicine monotherapy in terms of reducing the risk of pericarditis and related hospitalization rate in AF patients undergoing catheter ablation. MethodsConsecutive AF patients undergoing first catheter ablation were classified into 3 groups based on their colchicine use: Group 1: no colchicine; group 2: colchicine from 7 days before to 1 month after ablation; and group 3: colchicine from the day of the procedure to 1 month after. Standard institutional protocol was used to follow all patients for 1 year. ResultsA total of 1,075 patients were classified into groups 1 (n = 607), 2 (n = 213), and 3 (n = 255). Symptoms of acute pericarditis were reported in 129 patients (12%): group 1: n = 106 (17.5%); group 2: n = 4 (1.9%); and group 3: n = 19 (7.5%); P < 0.001. Rate of mild-moderate as well as severe pericarditis were significantly lower in group 2. In the multivariable regression analysis, pre- and post-ablation colchicine use was seen to be associated with significantly lower risk of acute pericarditis and related hospitalization compared with the other 2 groups. In addition, at 1-year follow-up, arrhythmia-free survival rate was significantly higher in paroxysmal AF patients receiving colchicine compared with the no-colchicine population. ConclusionsColchicine therapy starting 7 days before to 1 month after the ablation procedure was associated with significantly lower risk of acute pericarditis and related hospitalization. In addition, paroxysmal AF patients receiving colchicine had a higher arrhythmia-free survival rate compared with those not receiving colchicine.

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.

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

Circulating miR-20b-5p and miR-330-3p are novel biomarkers for progression of atrial fibrillation: Intracardiac/extracardiac plasma sample analysis by small RNA sequencing.

Circulating microRNAs (miRNAs, miR) have been considered as biomarkers reflecting the underlying pathophysiology in atrial fibrillation (AF). Nevertheless, miRNA expression in the peripheral blood samples might not reflect a cardiac phenomenon since most miRNAs are expressed in numerous organs. This study aimed to identify the cardiac-specific circulating miRNAs as biomarkers for AF. Plasma samples were obtained from a luminal coronary sinus catheter (CS, cardiac-specific samples) and femoral venous sheath (FV, peripheral samples) in patients with AF and paroxysmal supraventricular tachycardia (control, CTL) undergoing catheter ablation. The circulating miRNA profiles were analyzed by small RNA sequencing. Differently expressed miRNAs between AF and CTL were identified in each sample of the CS and FV; miRNAs exhibiting similar expression patterns in the CS and FV samples were selected as candidates for cardiac-specific biomarkers. The selected miRNAs were related to the outcome of catheter ablation of AF. Small RNA sequencing detected 849 miRNAs. Among the top 30 most differently expressed miRNAs between AF and CTL, circulating hsa-miR-20b-5p, hsa-miR-330-3p, and hsa-miR-204-5p had a similar pattern in the CS and FV samples. Another set of peripheral blood samples was obtained from AF patients undergoing catheter ablation (n = 141). The expression of the miR-20b-5p and miR-330-3p, but not the miR-204-5p, negatively correlated with the echocardiographic left-atrial dimension and was decreased in patients with AF recurrence as compared to those without AF recurrence during a 1-year follow-up. Circulating miR-20b-5p and miR-330-3p can be cardiac-specific biomarkers for atrial remodeling progression and arrhythmia recurrence after catheter ablation in AF patients.

Cost-effectiveness analysis of digital therapeutics for home-based cardiac rehabilitation for patients with atrial fibrillation after catheter ablation.

In recent years, numerous guidelines and expert consensuses have recommended that digital technologies and products, such as digital therapeutics (DTx), be incorporated into cardiac rehabilitation (CR). The study aims to compare the cost-effectiveness of DTx for home-based CR (HBCR) with that of the conventional HBCR for patients with atrial fibrillation (AF) after catheter ablation in a real-world clinical setting. Based on a single-center, prospective, blinded, randomized, parallel controlled trial of DTx-based HBCR for AF patients after catheter ablation, 100 AF patients undergoing catheter ablation were selected and randomized at a 1:1 ratio into a UC group (conventional HBCR) and DT group (DTx-based HBCR). The intervention lasted for 12 weeks. Medical cost data and clinical efficacy data (VO2max) were acquired from trial data. Effect data (QALYs, anxiety and depression status, health beliefs related to cardiovascular disease, and exercise self-efficacy) were obtained from a patient questionnaire. The cost-effectiveness analysis was conducted to assess the economic benefits of DTx-based HBCR versus conventional HBCR, and the robustness of the results was verified by sensitivity analysis. In the DT group (n = 49), the mean QALYs increased 0.119 ± 0.09, VO2max increased 9.3 ± 8.0 mL/(min*kg), anxiety, depression, health belief, and exercise self-efficacy had improved, and the total medical cost was 75,080.55 ± 19,746.62 CNY. In the UC group (n = 48), the mean QALYs increased 0.077 ± 0.06, VO2max increased 4.9 ± 6.6 mL/(min*kg), anxiety, depression, health belief, and exercise self-efficacy had improved, and the total medical cost was 73,972.66 ± 16,582.04 CNY. The difference in the medical cost was 1107.89 CNY, and the incremental cost-effectiveness ratio was 33,572.42 CNY/QALY, which was lower than the willingness-to-pay threshold of 85,698 CNY (China's per capita GDP in 2022). DTx-based HBCR is more effective and cost-effective than conventional HBCR.

Abstract 11139: Role of Esophageal Cooling in the Prevention of Esophageal Injury in Atrial Fibrillation Catheter Ablation: A Systematic Review and Meta-Analysis of Randomized Controlled Studies

Introduction: Trials evaluating the role of esophageal cooling in the prevention of esophageal injury in patients undergoing atrial fibrillation (AF) catheter ablation have yielded mixed results. The aim of our study is to evaluate the efficacy of esophageal cooling in the prevention of esophageal injury in patients undergoing AF catheter ablation. Methods: Comprehensive search of MEDLINE, EMBASE, and Cochrane databases through April 2022 for randomized controlled trials (RCTs) evaluating the role of esophageal cooling compared with control in the prevention of esophageal injury during AF catheter ablation. The study's primary outcome was the incidence of total esophageal injury. Secondary outcomes included the incidence of severe esophageal injury, the incidence of mild to moderate esophageal injury, procedural duration, posterior wall duration, total radiofrequency (RF) time, acute reconnection incidence, and ablation index. Results: The meta-analysis included 4 RCTs with total of 294 patients. There was no significant difference in the incidence of total esophageal injury between esophageal cooling and control (15% vs. 19%; Relative Risk [RR] 0.86; 95% confidence interval [CI] 0.31 - 2.41; I 2 = 63%). However, compared with control, esophageal cooling showed lower risk of severe esophageal injury (0.01% vs. 0.09%; RR 0.21; 95% CI 0.05 - 0.80). There were no significant differences among the two groups in mild to moderate esophageal 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 duration (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). Conclusions: Among patients undergoing AF catheter ablation, esophageal cooling did not show a significant difference in the incidence of total esophageal injury. However, it has shown a significant decrease in the risk of severe esophageal injury without affecting the ablation process. This can help decrease the progression to atrial-esophageal fistula. Further large RCTs are needed to better evaluate the role of esophageal cooling in the prevention of esophageal injury.

Heart Rate Decrease After Atrial Fibrillation Catheter Ablation Predicts Decompensated Heart Failure After the Procedure.

Background: Decompensated heart failure (DHF) can complicate catheter ablation for atrial fibrillation (AF). We investigated the association between heart rate and DHF in AF patients undergoing catheter ablation.Methods and Results: In all, 1,004 consecutive patients who underwent initial ablation for AF (mean [±SD] age 68±10 years; 34% female; persistent AF n=513 [51%]) were enrolled in the study. Heart rate was assessed before and after ablation. DHF was defined as heart failure requiring medical therapy within 2 days after the procedure. The incidence of DHF was 2% (22 of 1,004 patients). Patients with DHF had a higher prevalence of a history of symptomatic heart failure (11/22 [50%] vs. 160/982 [16%]; P<0.0001) and a greater degree of heart rate decrease after the procedure (−21±29 vs. 2±21 beats/min; P=0.001) than those without DHF. On multivariate analysis, heart rate decrease was a significant independent predictor of DHF (hazard ratio 0.8; 95% confidence interval 0.7–0.9; P=0.004; 10 beats/min-increment).Conclusions: In patients undergoing AF ablation, a decrease in heart rate after the procedure was an independent predictor of DHF.

2021 Korean Heart Rhythm Society Guidelines for Catheter or Surgical Ablation of Atrial Fibrillation

Rhythm control therapy is used in atrial fibrillation (AF) management to improve AF-related symptoms along with rate control. AF catheter ablation is effective in maintaining sinus rhythm and has an acceptable complication rate. Compared with antiarrhythmic drugs, AF catheter ablation is superior with respect to arrhythmia-free survival and improvement in the quality of life. Therefore, AF ablation is recommended for rhythm control after the failure of antiarrhythmic drugs and is sometimes considered a first-line therapy for AF patients. Radiofrequency and cryoballoon ablation show similar efficacy, with slightly different complication profiles. Surgery for AF is also an effective rhythm control therapy and should be considered in patients undergoing cardiac surgery or in those with failed catheter ablation. For patients undergoing AF catheter ablation, performing ablation under uninterrupted warfarin or non-vitamin K oral anticoagulant treatment is recommended for periprocedural stroke risk management. Here, we review existing data and discuss the general principles of AF catheter and surgical ablation in patients with AF.

Factors associated with silent cerebral events during atrial fibrillation ablation in patients on uninterrupted oral anticoagulation.

Silent cerebral events (SCEs) are related to the potential thromboembolic risk in atrial fibrillation (AF) ablation. Periprocedural uninterrupted oral anticoagulation (OAC) reportedly reduced the risk of SCEs, but the incidence still remains. AF patients undergoing catheter ablation were eligible. All patients took non-vitamin K antagonist oral anticoagulants (NOACs; n = 248) or vitamin K antagonist (VKA; n = 37) for periprocedural OAC (>4 weeks) without interruption during the procedure. Brain magnetic resonance imaging was performed within 2 days after the procedure to detect SCEs. Clinical characteristics and procedure-related parameters were compared between patients with and without SCEs. SCEs were detected in 66 patients (23.1%; SCE[+]) but were not detected in 219 patients (SCE[-]). Age was higher in SCE[+] than in SCE[-] (66 ± 10 vs. 62 ± 12 years; p < .05). Persistent AF prevalence, CHADS2 /CHA2 DS2 -VASc scores, serum NT-ProBNP levels, left atrial dimension (LAD), and spontaneous echo contrast prevalence in transesophageal echocardiography significantly increased in SCE[+] versus SCE[-]. SCE[+] had lower baseline activated clotting time (ACT) before heparin injection and longer time to reach optimal ACT (>300 s) than SCE[-] (146 ± 27 vs. 156 ± 29 s and 44 ± 30 vs. 35 ± 25 min; p < .05, respectively). In multivariate analysis, age, LAD, baseline ACT, and time to reach the optimal ACT were predictors for SCEs. The average values of the ACT parameters were significantly different among NOACs/VKA. Age, LAD, and intraprocedural ACT kinetics significantly affect SCEs during AF ablation. Different anticoagulants have different impacts on ACT during the procedure, which should be considered when estimating the risk of SCEs.

Using Machine Learning to Predict 30-Day Hospital Readmissions in Patients with Atrial Fibrillation Undergoing Catheter Ablation.

Atrial fibrillation (AF) cases are expected to increase over the next several decades, due to the rise in the elderly population. One promising treatment option for AF is catheter ablation, which is increasing in use. We investigated the hospital readmissions data for AF patients undergoing catheter ablation, and used machine learning models to explore the risk factors behind these readmissions. We analyzed data from the 2013 Nationwide Readmissions Database on cases with AF, and determined the relative importance of factors in predicting 30-day readmissions for AF with catheter ablation. Various machine learning methods, such as k-nearest neighbors, decision tree, and support vector machine were utilized to develop predictive models with their accuracy, precision, sensitivity, specificity, and area under the curve computed and compared. We found that the most important variables in predicting 30-day hospital readmissions in patients with AF undergoing catheter ablation were the age of the patient, the total number of discharges from a hospital, and the number of diagnoses on the patient’s record, among others. Out of the methods used, k-nearest neighbor had the highest prediction accuracy of 85%, closely followed by decision tree, while support vector machine was less desirable for these data. Hospital readmissions for AF with catheter ablation can be predicted with relatively high accuracy, utilizing machine learning methods. As patient age, the total number of hospital discharges, and the total number of patient diagnoses increase, the risk of hospital readmissions increases.

Predicting long-term freedom from atrial fibrillation after catheter ablation by a machine learning algorithm: Validation of the CAAP-AF score.

BackgroundPreprocedural clinical predictors of the successful maintenance of sinus rhythm may contribute to optimal treatment strategies for atrial fibrillation (AF). The CAAP‐AF score, a novel simple tool scored as 0‐13 points (including six independent variables) has been proposed to predict long‐term freedom from AF after catheter ablation. To clarify its reproducibility, we examined the CAAP‐AF score's predictive performance and then created subgroups to best predict AF recurrence by using a machine learning algorithm.MethodsWe studied 583 consecutive patients who underwent initial AF catheter ablation at our institute (median CAAP‐AF score, 5; age, 66 ± 10 years old; female, 28.3%; coronary artery disease, 10.8%; left atrial diameter, 39.9 ± 6.6 mm; number of antiarrhythmic drugs failed, 0.4 ± 0.6; nonparoxysmal AF, 45.3%). All were systematically followed up with an endpoint of atrial tachyarrhythmia recurrence after the last ablation procedure.ResultsDuring the 1.8 ± 1.2‐year follow‐up, 157 patients had atrial tachyarrhythmia recurrence. Repeated procedures were performed (n = 115). Arrhythmia recurrence after the last session occurred in 69 patients. We created Kaplan‐Meier curves for freedom from AF after final AF ablation for ranges of CAAP‐AF scores; these confirmed the original study results. The machine learning using Classification and Regression Trees divided the patients into three categories by the risk score: low (score ≤5), intermediate (score 6‐8), and high (score ≥9).ConclusionsThe CAAP‐AF score was useful to stratify the atrial tachyarrhythmia recurrence risk in AF patients undergoing catheter ablation into three categories. The score should be considered when deciding whether to perform AF ablation in clinical practice.