Catheter Ablation Of Atrial Fibrillation Research Articles

Fewer redo procedures in catheter ablation of atrial fibrillation: data from the swedish national catheter ablation registry

Abstract Background The number of patients undergoing catheter ablation of atrial fibrillation (AF) is continuously growing, and techniques are improving. However, AF recurrences are still common and demand frequent redo procedures that expose patients to repeat complication risks and cause extensive health care costs. Real-life data regarding redo rates is scarce. Using a national registry, we examined current trends in long-term outcomes as illustrated by the need for redo procedures. Purpose The purpose of this study was to investigate the long-term outcome of catheter ablation of AF as a function of when the initial procedure was performed. Methods The Swedish Catheter Ablation Registry covers virtually all (>97%) catheter ablations performed in Sweden since 2005. Patients >18 years of age undergoing pulmonary vein isolation (PVI) during January 1st 2006 until December 31st 2020 were included in the analysis. Follow up data was registered until December 31st 2021. The number of procedures performed, characteristics of patients, acute success (defined as all pulmonary veins isolated), and repeat ablation at 1 and 3 years were analyzed. Characteristics and periprocedural data were compared between 2006, 2015 and 2020 to find possible trends. Results A total of 23909 PVI were performed during the studied period. In 2006, 2015 and 2020, respectively, 352, 1861 and 2609 procedures were performed, constituting 18%, 40% and 48% of all ablation procedures. There was an increase in patient age (58, 62, 64 years) and more women were ablated (22%, 27%, 28%) over time. Acute success rate remained high at 98% during the study period. Repeat ablation at 1 and 3 years was 23% and 45% respectively for patients ablated in 2006, compared to 14% and 30% in 2015, and 10% and 23% in 2018 (p <0.001 for both trends), see figure 1. Conclusion In a setting of a universal healthcare system, with a continuous increase in amount of catheter ablation of AF, in spite of an unchanged, high acute success throughout the study period, a continuous decrease of repeat ablation was observed indicating a substantial gain in patient value by AF ablation over time.Repeat ablation atrial fibrillation

Single versus double transseptal puncture for pulmonary vein isolation with radiofrequency catheter ablation for atrial fibrillation - insights from "Go for Zero Fluoroscopy" registry

Abstract Background Transseptal puncture is one of the most challenging steps in catheter ablation of atrial fibrillation (AF) because of the potential risk of complication. While single TSP reduces the puncture-related risk, double TSP simplifies the procedure (immediate signal visualization in pulmonary veins, avoidance of multiple changes of catheters through the single sheath). The purpose of this study was to analyze the impact of single versus double TSP during pulmonary vein isolation (PVI) with radiofrequency (RF) catheter ablation for AF on the fluoroscopy usage and procedure time. Methods Data reported from the international, multicenter prospective „Go For Zero Fluoroscopy Registry" performed in years 2018–2019 were analyzed. Overall 25 European electrophysiology centers from 14 countries and up to 5 operators from each center were enrolled. Only isolated PVI procedures were analyzed. Results A total data of 393 PVI RF procedures were collected from 25 centers. The median dose-area-product (DAP), fluoroscopy time and overall procedure time were: 810 (325 – 1839) cGy*cm2, 8 (4 – 14) minutes and 124 (92 – 168) minutes, respectively. Single TSP was associated with significantly higher DAP: 984 (459 – 1939) vs 667 (227 – 1469) cGy*cm2 (p=0.002), longer fluoroscopy time: 11 (6 – 19) vs 6 (3 – 11) minutes (p<0.001) and longer overall procedure time: 133 (103 – 168) vs 110 (90 – 168) minutes (p=0.003) as compared with double TSP. Single and double TSP group did not differ significantly in regards of general anesthesia usage, circular and multipolar mapping catheter use (p>0.05). However, single TSP was performed by operators with longer EP lab experience: 10 (4 – 15) vs 3 (0 – 10) years (p<0,001). Conclusions Double TSP is related with lower fluoroscopy usage and shorter overall procedure time of pulmonary vein isolation with radiofrequency catheter ablation for atrial fibrillation.

LA strain analysis in patients undergoing atrial fibrillation ablation using cryoballoon or pulsed-field-ablation

Abstract Background Catheter ablation for atrial fibrillation (AF) is increasing as rhythm control therapy. Besides thermal ablation approaches, such as cryoballoon ablation (CBA), a novel non-thermal and tissue-specific ablation modality – pulsed field ablation (PFA) – has been introduced. Left atrial reservoir strain (LArS) has been suggested to predict arrhythmia recurrences after AF ablation. Up to now, data describing LArS in patients undergoing their first AF ablation using PFA or CBA are sparse. Purpose To compare LArS in patients undergoing first catheter ablation for AF using either PFA or CBA. Methods Patients with transthoracic echocardiography prior to their first catheter ablation for AF were included. Patients in AF during transthoracic echocardiography, with poor 2D image quality and those that did not have a transthoracic echocardiography after AF ablation were excluded. Clinical characteristics and echocardiography parameters were analyzed. LArS was measured before and after AF ablation and was correlated with the recurrence of atrial arrhythmias in the follow-up period. Results Of 267 patients undergoing their first AF ablation, 67 patients (69% male, 65 ± 11 years) fulfilled the inclusion criteria and were further analyzed. AF ablation was performed using PFA in 55% and CBA in 45% of patients. Baseline characteristics were similar in both groups. Before ablation LArS was similar for PFA (17.69 ± 6.92%) and CBA patients (19.38 ± 9.42%, P=0.45). After AF ablation, LArS did not change significantly compared to the values before (before ablation: 20.96 ± 15.9 vs. after ablation: 19.87 ± 9.38, P=0.18), irrespective of the ablation mode (PFA before: 17.69 ± 6.92%vs. PFA after: 18.06 ± 8.9%, P=0.53; CBA before: 19.38 ± 9.42% vs. CBA after: 21.08 ± 9.48%, P=0.36). After a median of 190 days [95% confidence interval: 89 - 454 days], 25 patients (37%) experienced an arrhythmia recurrence (PFA: 38%, CBA: 37%). Comparing patients with and without arrhythmia recurrences, LArS before catheter ablation was lower in those experiencing an arrhythmia recurrence (16.02 ± 6.8%) compared to those without arrhythmia recurrence (25.58 ± 20.32%, P=0.02). However, this was independent from the ablation mode (PFA: AF-recurrence: 16.51 ± 4.27 vs. no recurrence: 21.31 ± 15.9, P=0.19; CBA: AF-recurrence: 15.48 ± 9.03 vs. no recurrence: 27.34 ± 22.14, P=0.07). Univariable regression analysis - including sex, age and comorbidities - revealed a trend for baseline LArS being associated with arrhythmia recurrence (HR 0.92, 95% CI: 0.86 – 1.01; P=0.065). Conclusions This hypothesis generating study indicates that LArS is not affected by AF ablation irrespective of the ablation mode. Patients with lower LArS before ablation had more arrhythmia recurrences independent of the ablation mode. A larger patient population is needed to assess the association of LArS and arrhythmia recurrences after AF ablation using different ablation modalities.

Long-term efficacy and safety of ablation for atrial fibrillation in patients with hypertrophic cardiomyopathy

Abstract Background Hypertrophic cardiomyopathy (HCM) is often accompanied by atrial fibrillation (AF) but data on safety and long-term outcomes after catheter ablation for AF in HCM are scarce. Purpose To investigate safety, long-term efficacy and clinical outcomes following AF ablation in patients with HCM and in matched controls. Methods Patients with HCM (n=76) undergoing a first catheter ablation for AF or atrial flutter between 1999 and 2022 at a University Hospital in Sweden were included (age 64±12 years, 43% female). Diagnosis of HCM was based on the European Society of Cardiology definition (left ventricular wall thickness ≥15 mm or ≥13 mm not solely explained by abnormal loading conditions, and combined with family history, genetic components and/or electrocardiogram abnormalities). Patients with HCM were matched with controls (n=152) based on age, gender, ablation type and intervention-year. Patients were followed for a mean of 5 years and study endpoints included heart failure hospitalization (HFH), stroke and mortality. Cox regression analyses were performed for the association between HCM and the endpoints. Results Among the overall population, 121 (53%) underwent pulmonary vein isolation (PVI), 62 (27%) isthmus ablation and 45 (20%) His-Bundle ablation. Patients with HCM had a shorter mean duration of AF before ablation (48 months vs. 66 months; p=0.047) and more severe symptoms as indicated by a higher EHRA class (EHRA class IV: 30% vs. 10%; p<0.01). Procedural success rate of PVI and isthmus ablation was lower in patients with versus without HCM (88% vs. 97%; p=0.02). Procedure related complications (vascular complications, tamponade) were overall similar in both groups (9% in HCM vs. 5% in controls, p=0.17) except for higher rates of pulmonary oedema in patients with HCM (7% vs 1%, p=0.03). There was a nearly two-fold increase in risk of AF recurrence after PVI or isthmus ablation in patients with HCM compared to controls (OR 1.95; 95% CI 1.06-3.58; p=0.03). During follow-up, patients with HCM had an increased risk of HFH (HR 2.55, 95% CI 1.21-5.36, p=0.01) but not of stroke or mortality (Figure 1). Conclusion AF ablation was overall safe in patients with HCM but less effective. Patients with HCM had an increased risk of the individual endpoint of HFH after AF ablation but not stroke or mortality during long-term follow-up.

Timing of early recurrence of atrial fibrillation during the blanking period after catheter ablation for persistent atrial fibrillation and implications for long-term success: a multicentre study

Abstract Background After catheter ablation (CA) for atrial fibrillation (AF), early recurrences of AF (ERAF) that occur within a 90-day post-ablation "blanking period" are considered to represent transient post-ablation pro-arrhythmia. Purpose To determine if the timing of early recurrence of AF during the traditional 90-day post-CA blanking period is associated with long-term AF recurrence after CA for persistent AF (PsAF). Methods We performed a multicentre retrospective study of patients undergoing first-time CA for PsAF between 2015-2018. All patients had undergone pre-CA DCCV. Incidences of ERAF during the post-CA blanking period were reviewed, and patients were categorised into three groups based on the timing of last episode of ERAF during the blanking period: (1) no ERAF (reference population); (2) last ERAF <30 days post-CA; (3) last ERAF 31-90 days post-CA. The primary outcome was long-term recurrence of atrial arrhythmia, i.e. time to first recurrence of atrial arrhythmia occurring beyond the first 90 days after CA. Patients who had ERAF and exited the blanking period in AF (i.e. those with immediate recurrence at 90 days) were excluded from this analysis. Results 331 patients were identified from five centres. 206 patients had no ERAF during follow-up, 124 patients had ERAF during the blanking period, and in one patient the presence of ERAF was not documented. Of the 124 patients experiencing ERAF during the 90-day post-CA blanking period, the timing of the last episode was known in 122 patients (Table 1). Of these, 58 patients exited the 90-day blanking period in AF and were excluded. Over median post-CA follow-up of 590 days, 147 patients (54%) experienced the primary outcome. Compared with Group 1 (no ERAF), ERAF within each of the time periods was associated with a statistically significant progressively increased risk of long-term recurrence (Group 2, last ERAF <30 days post-CA: hazard ratio [HR] 1.95 [95% CI 1.15-3.31]; Group 3, last ERAF 31-90 days post-CA: HR 4.86 [95% CI 2.13-11.08]; Figure 1). Conclusion ERAF during the traditional 90-day post-CA blanking period is associated with long-term AF recurrence, with later recurrence within the 90-day period conferring greater risk. Patients with ERAF during the blanking period may need to be considered for earlier repeat intervention where clinically appropriate.

Analysis of the left atrial appendage function by intracardiac echocardiography in patients with atrial fibrillation

Abstract Introduction Intracardiac echocardiography (ICE) is frequently performed during catheter ablation procedures in order to guide the transseptal puncture and has been recently used to evaluate the morphology of the LAA. Purpose The objective of this study was to evaluate the feasibility of using an ICE catheter placed in the coronary sinus (CS) to delineate the LAA function during catheter ablation for atrial fibrillation. Methods We included 21 consecutive patients (age 62±9 years, 5 women, 6 paroxysmal AF) who underwent catheter ablation for AF. An 8-Fr phased-array ICE catheter was used to obtain images of the LAA, while in sinus rhythm. The LAA was visualized with the ICE probe placed sequentially in the left atrium (LA, Figure A), with the ultrasound section plane parallel to the long axis of the left ventricle (LV), and in the CS, with the ultrasound section plane perpendicular to the LV long axis (Figure B). LAA emptying flow velocity, and LAA fractional area change (FAC) were used to evaluate LAA function. There were no procedural complications. Results ICE imaging was possible in all cases. The LAA peak flow velocity was similar when the ICE catheter was placed in the LA and in the CS (64±7 cm/s and 62±5cm/s respectively, P=NS). The LAA FAC was significantly lower when the ICE catheter was placed in the CS when compared to an LA location (14±6% vs 36±14%; P<0.001). The LAA FAC measured from the LA correlated with the mitral annular plane systolic excursion while the LAA FAC measured from the CS did not. Thus, LAA contraction in a plane perpendicular to the LV long axis is independent of the LV longitudinal contraction. These results suggest that in our patient group most of the LAA contraction was due to the longitudinal movement of the LV base during systole and diastole. Conclusions Imaging of LAA using an ICE probe positioned in the LA and CS was feasible in all cases. The LV longitudinal contraction appears to impact the LAA function.

Procedural findings and follow-up results of catheter ablation of atrial fibrillation in patients after radiation therapy for breast cancer

Abstract Backround Data on breast cancer radiation therapy (RT) associated atrial cardiomyopathy and its potential role in the pathophysiology of atrial fibrillation (AF) is very limited. Objectives To investigate the effect of breast cancer radiotherapy (RT) on atrial cardiomyopathy and its possible role in the pathophysiology of atrial fibrillation. What is the therapeutic success of antral pulmonary vein isolation (PVI) with possible substrate modifications (CFAE) in patients with breast cancer radiation therapy and paroxysmal or persistent atrial fibrillation. Methods We searched the institution’s data base for patients who received RT for breast cancer and underwent subsequently 3D mapping guided AF ablation. Intraprocedural mapping data and short- and long-term results of ablation were evaluated according to "no low voltage" and "low voltage" present. Low voltage amplitudes in bipolar electrograms were defined as <0.5 mV for endocardial maps created during SR and <0.3mV during AF. Ablation strategy comprised pulmonary vein isolation (PVI) ± additional substrate modification according to the mapping results. Follow Up (FU) was evaluated using repetitive 7-days Holter ECG and clinical visits. Results We included 45 patients (all female, 70.9±7.2 years) with paroxysmal or persistent AF (n=18 and n=27). In 3D mapping, 60% of the patients (27/45) showed left atrial low voltage (LV group) with the majority showing low voltage in the anterior wall of the left atrium (LA) in 18 of 45 patients (40%). PVI with ablation of complex fractionated signals (CFAE) was predominantly performed (18/27). After one ablation, 33.3% (9) of the patients in the LV group were recurrence-free and after an average of 1.9 ablations, freedom from recurrence was achieved in 21 patients with low voltage (77.8%). In 18 patients, no low voltage was detected (NLV group) and PVI only was performed in the majority (14/18). In this NLV group, 61.1% (11) of the patients were recurrence-free after one ablation and freedom from recurrence was achieved in 72.2% (13) after an average of 1.2 ablations. Conclusion Thoracic radiation therapy in patients with breast cancer can lead to low voltage in the LA with the predominant low voltage location being the anterior wall of the LA. An extended ablation strategy (PVI & CFAE) can show good treatment options in these patients with atrial fibrillation, with high freedom from recurrence after a mean of two ablation procedures.Freedom from recurrence after ablationCharacteristics of left atrium (LA)

Comparison of complications during catheter ablation of atrial fibrillation between radiofrequency and cryoballoon ablation: insights from a nation-wide claims-based database

Abstract Background Few large-scale, real-world studies have compared the safety of radiofrequency (RF) catheter ablations (CA) with that of cryoballoon ablations of atrial fibrillation (AF), especially in east Asian countries. Methods This retrospective, cross-sectional study used a nationwide administrative claims database, to compare complication-incidence rates between patients who underwent RFCA and cryoballoon ablation of AF. We used data from Medical Data Vision Co., Ltd, that is derived from the health claims, Diagnosis Procedure Combination (DPC) system, and flat-fee payment system in Japan. We first extracted hospitalization records with CA with diagnosis of AF. Exclusion criteria were 1) records with diagnoses of atrial flutter or atrial tachycardia, 2) patients aged <20 years old, 3) CA of AF performed other than RFCA or cryoballoon, 4) records with insufficient clinical data, and 5) patients who were prescribed both direct oral coagulants and warfarin. Complications were defined using the following ICD-10 diagnosis codes: major bleeding (I31.9, I97.1, J98.5, J048, J0021); thromboembolism (H342, I24, I269, I740, I741, I744, I748, I749, K550, K868, N280, or T790); ischemic stroke (G45, or I63); cardiac tamponade (I31.9, I97.1, or J98.5); and vascular access complications (hematoma: S701, S801, T140 or T810; and/or pseudoaneurysms: I72.4). Logistic regression analyses were performed to estimate odds ratios and 95% confidence intervals (CI) for major bleeding, systemic thromboembolism, ischemic stroke, and cardiac tamponade. Results Among the 32,797,540 records between June 2011 and August 2020 from 426 hospitals, 41,347 records who underwent CA of AF (Median 68 [60–74] years old, 30.2 % women) were included in the study. A total of 36,729 RFCA (88.8%) and 4,618 cryoballoon ablation (11.2%) cases were included in the cohort. Major bleeding, systemic thromboembolism, ischemic stroke, cardiac tamponade, and vascular access complications occurred in 194 (0.5%), 193 (0.5%), 116 (0.3%), 414 (1.0%) and 115 (0.3%) patients, respectively. As a result of logistic regression analysis, when cryoballoon ablation was used as a reference, RFCA was associated with higher risk of cardiac tamponade (OR 1.54, 95% CI 1.09–2.25, P = 0.02), while it was not associated with higher or lower risk of other complications (major bleeding OR [95% CI ]1.21 [0.77–2.04]; thromboembolism 1.74 [1.03–3.22]; ischemic stroke 1.88 [0.94–4.47]; vascular access complication; 1.00 [0.58–1.87]). Conclusion Compared to cryoballoon ablations, RFCA was associated with higher risk of cardiac tamponade, using nationwide administrative claims database.

Procedural outcomes of fluoroscopy-less catheter ablation for atrial fibrillation

Abstract Background Radiofrequency catheter ablation is superior therapy to antiarrhythmic drugs for maintaining sinus rhythm in atrial fibrillation (AF) patients. Traditional fluoroscopy-guided AF ablation poses risks of prolonged radiation exposure for both patients and medical staff. Recent advancements in fluoroscopy-less catheter ablation techniques offer potential solutions, but comprehensive data on their effectiveness and safety are lacking. Purpose To evaluate the procedural outcomes and safety of fluoroscopy-less catheter ablation for AF compared to fluoroscopy-guided ablation. Methods Retrospective observational study of consecutive AF ablations (N=881) conducted at a university teaching hospital (Hamilton Health Sciences, Hamilton, Ontario) from November 2017 to September 2022. An electro-anatomical mapping system and ICE was used in all cases. Baseline characteristics and procedural outcomes between the fluoroscopy-less and fluoroscopy-guided groups were compared. Cases that used <60 seconds of fluoroscopy (occasionally used by operators during the placement of an esophageal probe) were included in the fluoroscopy-less group (N= 68). Results Mean age of individuals was 60.6 ± 11 years, 71.7% were male, 72.6% had paroxysmal AF, mean CHA2DS2-VASc score was 1.6 ± 1.4, 11.1% had prior heart failure, and mean left ventricular ejection fraction was 57.5 ± 15%. There were no significant differences in patient baseline characteristics between the fluoroscopy-less and fluoroscopy groups. Total procedure and fluoroscopy times were lower in the fluoroscopy-less group compared to the fluoroscopy-guided group (169.3 ±42 minutes vs. 192.1 ±54 minutes, p<0.0001 and 0.024 ±0.10 vs. 10.0 ±7.4 minutes , p<0.0001). Fluoroscopy-less AF ablation remained an independent predictor of lower procedure times following adjusting for the use of general anesthesia, high-power short-duration, presence of trainees, AF pattern, redo cases, and type of mapping system. Complication rates were similar between fluoroscopy-less and fluoroscopy-guided ablation (1.9% vs. 3.8%, p=0.11). Conclusion Fluoroscopy-less catheter ablation for AF appears to have similar procedural outcomes and safety than fluoroscopy-guided AF ablation.

Detecting epicardial connection through intercaval bundle using intra-atrial activation sequence during right pulmonary vein pacing

Abstract Background An epicardial connection (EC) through the intercaval bundle (EC-ICB) between the right pulmonary vein (RPV) and the right atrium (RA) is one of the reasons for the need of carina ablation for PV isolation. Purpose We evaluated the intra-atrial activation sequence during RPV pacing after failure of ipsilateral RPV isolation and sought to identify specific conduction patterns in the presence of the EC-ICB. Methods This study included 223 consecutive patients undergoing initial catheter ablation of atrial fibrillation. If the RPV was not isolated by circumferential ablation or reconnected during the waiting period, an exit map during mid RPV carina pacing was created. If the earliest site of the exit map was the RA, the patient was classified into the EC-ICB group. During the exit map, intra-atrial activation sequence and RPV-HRA time were evaluated. Results First-pass isolation of the RPV was not obtained in 36 patients (16.1%), and 22 patients (9.9%) showing reconnection. Among them, 12 patients were classified into the EC-ICB group and 28 patients into the Non-EC-ICB group after excluding multiple ablation lesion sets or incomplete mapping. Intra-atrial activation sequence showed different patterns between the two groups. RPV-HRA time was significantly shorter in the EC-ICB group compared to the Non-EC-ICB group (69.2 ± 15.2 ms v.s. 148.6 ± 51.2 ms. P<0.001), and RPV-HRA time<89.0ms was highly predictive for existence of the EC-ICB (sensitivity 91.7 %, specificity 89.3 %). Conclusions The EC-ICB can be effectively detected by intra-atrial sequencing during RPV pacing and RPV-HRA time<89.0ms was highly predictive.

Acute kidney injury after catheter ablation of atrial fibrillation: comparison between different energy sources

Abstract Introduction Pulsed field ablation (PFA) is an innovative technology recently adopted for the treatment of atrial fibrillation (AF). Preclinical and clinical studies have reported a reassuring safety profile, because of its tissue specific effect, sparing adjacent tissues. However, two cases of acute kidney injury (AKI) secondary to hemolysis after PFA have recently been reported. Purpose To compare the incidence of AKI and hemolysis after catheter ablation of AF using radiofrequency energy (RFA), cryo-balloon energy (CBA) and PFA using a pentaspline catheter. Method Patients undergoing catheter ablation of AF were consecutively enrolled in a prospective registry in a tertiary referral center between April 2010 and January 2024. Blood samples including renal parameters and hemolysis indicators were obtained prior to the procedure and the day after the procedure. AKI was defined as an increase in serum creatinine by 26.5 µmol/L within up to 10 days after the procedure . Results A total of 2602 patients (median age 64 years, 29.4% female) underwent catheter ablation for AF. 1707 (66.4%) were treated with RFA, 557 (21.7%) using CBA and 306 (11.9%) using PFA. Median net duration of ablation was 1669 (IQR 1207, 2164) seconds for RFA, 1046 (IQR 840, 1451) seconds for CBA and, 80 (IQR 48, 85) seconds (32 (IQR 19, 34) applications) for PFA. AKI was found in 21 (0.012%), 1 (0.002%) and 1 (0.003%) patients treated with RFA, CBA and PFA, respectively, p=0.245. The case with AKI after PFA received a total of 86 PFA applications. There was a significant positive correlation for the RFA group between the ablation duration and the creatinine level after the procedure, while there was no positive correlation for the CBA and PFA group (Figure). At least one hemolysis indicator (Bilirubin, LDH or Urea levels) was elevated the day after the procedure in 53.1%, 50.1% and 46.5% in the RFA, CBA and PFA group, respectively, p=0.12. Conclusion AKI appears to be very rare after PFA and comparable to thermal energy forms. Hemolysis does not seem to be dependent on the used energy source for pulmonary vein isolation. Minimal hemolysis occurs when PFA is applied as recommended by the manufacturer.Graphical Abstract

Left atrial and left ventricular positive and negative remodeling after catheter ablation of atrial fibrillation

Abstract Introduction Atrial fibrillation (AF) is associated with negative remodeling of left atrium (LA) and in later stages of diseases with negative remodeling of left ventricle (LV). Can radiofrequency ablation (RFA) of pulmonary veins cure AF and retain progression of arrhythmia? Purpose This study evaluated positive and negative remodeling of LA and LV after RFA of pulmonary veins and a 7-year follow-up. The patients were divided into 4 groups on the basis of Pulmonary Vein Isolation Outcome Degree (PVIOD 1-4), a new measure for the efficacy of catheter ablation of AF. Methods One hundred seventeen patients with symptomatic drug-refractory paroxysmal and persistent AF were treated with RFA. At baseline and after a 7 years of follow-up, 2-dimensional echocardiography was performed to assess LA diameter, left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD) and left ventricular ejection fraction (LVEF). Results After a 7-year follow-up 32.5% patients with successful single RFA of AF (PVIOD 1) showed significant positive LA and LV remodeling: LA diameter 39.3±0.6 vs 36.5±0.6 mm, p=0.0007; LVEDD 53.1±0.6 vs 50.9±0.7 mm, p=0.008; LVESD 34.7±0.8 vs 32.0±0.1 mm, p=0.005 and LVEF 56.8±0.8 vs 62.1±1.1 %, p=0.000008. In 29.1% of patients with success after multiple procedures (PVIOD 2) occurred significant reverse LA remodeling: LA diameter 41.9±0.7 vs 40.2±0.6 mm, p=0.04. Clinical success (PVIOD 3) after RFA was defined as a significant reduction in the number and duration of AF episodes with or without previously ineffective antiarrhythmic drugs (AAD) class I and III. In 14.5% of subjects with long-term clinical success (PVIOD 3 and baseline LA diameter 43.2±1.0 mm) remodeling of LA and LV was not occurred. In 23.9% of patients with procedural and clinical failure after RFA (PVIOD 4) long-term follow-up showed significant negative remodeling of LA and LV: LA diameter 44.7±0.7 vs 47.4±0.7 mm, p=0.006; LVEDD 52.8±0.9 vs 57.1±0.6 mm, p=0.0006; LVESD 36.5±1.1 vs 40.7±1.2 mm, p=0.006 and LVEF 50.7±1.7 vs 43.8±1.8 %, p=0.004. Conclusions Single successful RFA of pulmonary veins in early stage of AF with normal LA diameter cure arrhythmia, which was proved with LA and LV positive remodeling after a 7-year follow-up. With increase of LA diameter, the success of RFA decrease. The multiple procedures slow the progression of AF, but are less effective because of long periods of time between them. Clinical success and role of AAD therapy are also important in AF management. If AF is not treated with RFA properly on time it becomes progressive disease.

Colchicine prevents post-ablation atrial fibrillation recurrence: a systematic review and meta-analysis

Abstract Background Catheter ablation for atrial fibrillation (AF) is a commonly performed procedure with appreciable effectiveness; however, post-AF ablation recurrence is often observed. The pathophysiology behind this recurrence is often inflammation and oxidative stress triggered during the ablation procedure. Colchicine is a potent anti-inflammatory agent that has emerged as a promising therapeutic for preventing post-ablation AF recurrence; however, the data available on its efficacy are limited. Purpose This meta-analysis aimed to investigate the outcomes of post-ablation AF patients who received colchicine in the postoperative period. Methods A comprehensive literature search spanning major bibliographic databases was conducted to retrieve studies comparing outcomes in post-ablation AF patients who received colchicine versus those who did not. The outcomes of interest included AF recurrence, pericarditis, gastrointestinal side effects, and hospitalization. AF recurrence was determined with a 12-lead electrocardiogram and/or Holter monitoring. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were pooled from all studies using the DerSimonian and Laird random-effects model. Statistical significance was set at p ≤ 0.05. Results Six studies were included with 1791 patients (721 in the colchicine group and 1070 in the placebo group). Patients who received colchicine had significantly lower odds of AF recurrence on follow-up [OR: 0.62; 95% CI: 0.48, 0.79; p=0.0001] but had higher gastrointestinal side effects [OR: 2.67; 95% CI: 1.00, 7.12; p=0.05]. There were no statistically significant differences in acute pericarditis [OR: 0.54; 95% CI: 0.27, 1.05; p=0.07] or hospitalization [OR: 1.03; 95% CI: 0.73, 1.45; p=0.87]. Conclusion Prophylactic use of colchicine after catheter ablation in patients with AF leads to a reduction in AF recurrence, albeit with increased gastrointestinal side effects such as diarrhea and nausea. Colchicine use did not lead to a reduction in the rates of pericarditis and hospitalization after ablation. Large randomized controlled trials are necessary to evaluate the efficacy of colchicine in the prevention of AF recurrence, particularly focusing on the dose and duration of treatment to optimize the side effect profile.

Role of 3D-electro-anatomical mapping on procedural characteristics and outcomes in pulsed-field ablation for atrial fibrillation

Abstract Introduction While the utilization of dedicated 3D-electro-anatomical mapping (EAM) systems for catheter ablation of atrial fibrillation (AF) is crucial using radiofrequency, its potential benefits in pulsed-field ablation (PFA) remain uncertain. This is of particular interest, since some PFA ablation systems will soon be available with integrated 3D-EAM capabilities. Objectives To compare the procedural characteristics and outcomes of patients undergoing PFA for pulmonary vein isolation (PVI) with mapping and with no mapping. Methods We prospectively enrolled patients undergoing their first PVI at a tertary referral center. In patients undergoing PVI with mapping, a multipolar mapping catheter was used to create voltage maps during sinus rhythm pre- and post-ablation. In the non-mapping group PVI was confirmed by assessing entrance block via the PFA catheter. The first 30 cases with mapping were excluded to account for a potential learning curve. Results A total of 197 consecutive patients were included (age 65 [interquartile range (IQR) 58 – 72] years; indexed left atrial volume 40 [IQR 35 – 44] mL/m2). Among these, 127 patients (64%) underwent PVI with mapping and 70 patients (36%) with no mapping. The median procedure duration, left atrial dwell time and the fluoroscopic time for the mapping vs the non-mapping group were 55 [IQR 45 – 67] min vs. 28 [IQR 23 – 35] min (p < 0.001), 38 [IQR 30 – 49] min vs. 15 [IQR 11 – 21] min (p < 0.001), 11 [IQR 9 – 14] min vs. 8 [IQR 7 – 11] min (p < 0.001), respectively. In the mapping group in 9% (11/127 patients) at least 1 PV was incompletely isolated and required additional applications. Acute PVI success was 100%. There were two complications in the mapping group (one stroke, one coronary artery air embolism) and none were observed in the non-mapping group. The recurrence rate of atrial arrythmias during a median follow-up of 267 [IQR 164 – 419] days was 14% in the mapping group and 17% in the non-mapping group, p = 0.728. Conclusion In conclusion, the use of PFA with no mapping was associated with a significant decrease in procedural characteristics, while AF-recurrence was not significantly different. The routine use of mapping for PFA-PVI may not be needed.Figure 1

Impact of paroxysmal atrial fibrillation ablation on cardiac sympathetic nervous system: a prospective stratified randomized comparative study in patients with and without heart failure

Abstract Background Catheter ablation of atrial fibrillation (AF) might influence the cardiac sympathetic nervous system (CSNS). We sought to investigate the impact of AF ablation with 2nd generation cryoballoon catheter (CB) and contact force sensing radiofrequency ablation catheter (RF) on CSNS and the association of this effect with early AF recurrence in patients with and without heart failure (HF), using cardiac iodine-123-metaiodobenzylguanidine (MIBG) scintigraphy. Methods and Results One hundred sixty-five paroxysmal AF patients who were scheduled for ablation were enrolled. All patients were categorized into two groups: one with HF (n=31), defined as left ventricular ejection fraction ≤ 40% or previous history of hospitalization for worsening HF, and the other without HF (n=134). They were then randomly assigned to CB (17 patients with HF and 68 without HF) or RF (14 with HF and 66 without HF). MIBG scintigraphy was performed at baseline and 3 months post-ablation and the washout rate (WR) was measured. There were no significant changes in WR from baseline to 3 months after RF and CB ablation (28.7±18.6% to 27.9±16.7% in RF and 29.4±16.7% to 30.5±16.4% in CB). WR decreased more in patients with HF at 3 months after ablation than without HF, while WR significantly increased in patients without HF and there was a significant interaction in WR change between with or without HF (interaction p<0.001). WR change from the baseline to 3 months after ablation (dWR) was not significantly different between CB and RF, irrespectively of the HF presence. In the blanking period of 3 months after ablation, early AF recurrence (EAR) was observed in 37 (22%) patients with no antiarrhythmic drugs (17(21%) patients in RF and 20(24%) in CB). dWR was significantly greater in patients with than without EAR (4.0±14.1% vs -0.9±11.0%, p=0.027). Higher dWR (≥ 6.9% (AUC 0.644, 95%CI [0.535-0.753]) by ROC curve analysis) was independently associated with EAR (adjusted odds ratio = 4.15, 95%CI [1.87-9.22], p<0.001, adjusted for age, sex, and left atrial diameter). Conclusions Irrespectively of CB and RF, AF ablation might reduce adrenergic tone in patients with HF, while it might induce more adrenergic tone in patients without HF. Excessive adrenergic tone might be associated with early AF recurrence.WR changes before and after ablationdWR in patients with or without HF

Catheter ablation vs medical management for atrial fibrillation in patients with heart failure: a systematic review and metanalysis

Abstract Background Current guidelines recommend a class IIa recommendation for catheter ablation in Atrial Fibrillation [AFIB]. Traditionally, catheter ablation has been known to be more effective in maintaining sinus rhythm than pharmacological management. However, there is sparse evidence to suggest that this translates to improved clinical outcomes in patients with heart failure. We did a systematic review and meta-analysis of randomized trials to compare the efficacy of ablation vs medical management for AFIB in heart failure. Methods A systematic search was conducted for randomized trials from inception to Jan 2024 for studies comparing the outcomes of catheter ablation vs medical management for AFIB in heart failure. The primary outcome was all-cause mortality. Secondary outcomes were cardiovascular (CV) mortality, heart failure hospitalizations, change in LV ejection fraction (LVEF), AF recurrence rate, 6-minute walk test (6MWT), change in MLHFQ scores and cerebrovascular events. Random-effects models were used to calculate the pooled incidence, mean difference (MD), and risk ratios (RRs) with 95% confidence intervals (CIs). Results A total of 10 RCTs with 2,348 patients were included in this study. Pulmonary vein isolation was the mainstay ablation strategy used. Compared with medical management, Ablation was associated with a significant reduction in all-cause mortality (RR- 0.61; 95% CI, 0.48-0.78; P<0.0001). Ablation was also associated with lower cardiovascular (CV) mortality (RR- 0.52; 95% CI, 0.36-0.75; P<0.0004), heart failure hospitalizations (RR- 0.67; 95% CI, 0.54-0.82; P<0.0001) and AF recurrence rate (RR- 0.43; 95% CI, 0.25-0.75; P<0.003). The study showed an improvement in LVEF (RR - 6.05; 95% CI, 3.35-8.75; P<0.0001), 6MWT (RR- 13.99; 95% CI, 4.18-23.81; P<0.005) and in MLHFQ score (RR -6.98; 95% CI, -12.03 to -1.93; P<0.007. There was a statistically significant difference between the 2 cohorts in the rates of cerebrovascular events (RR- 0.68; 95% CI, 0.35-1.30; P<0.24). Conclusion Randomized trials have shown clear benefits with catheter ablation compared to medical management for AFIB in heart failure. Ablation has demonstrated significantly lower all-cause mortality, reduced CV mortality, HF hospitalizations, AFIB recurrence rate, and improvement in LVEF. Patients who underwent catheter ablation showed improvement in functional outcomes like 6MWT and MLHFQ scores. There was no difference in the incidence of cerebrovascular events compared to medical management. This study adds to the growing evidence in the literature for ablation therapy; however, more trials are needed to identify patients for optimal benefits across the spectrum of heart failure patients.Forest PlotsForest Plots

The prevalence and prognostic impact of low voltage zone in patients with cardiomyopathy after catheter ablation for atrial fibrillation

Abstract Background The low voltage zone (LVZ) in left atrium (LA) was observed in 20-30% of patients undergoing catheter ablation of atrial fibrillation (AF). Furthermore, LVZ was associated with not only AF recurrence but also prognosis. However, the prevalence and prognostic impact of LVZ in patients diagnosed with cardiomyopathy remained unclear. Purpose In this study, we focused on the patients with cardiomyopathy after AF ablation and investigated the prevalence and prognostic impact of LVZ after AF ablation. Methods This study is a single-center retrospective observational study. We enrolled 125 patients diagnosed with cardiomyopathy. All patients underwent voltage mapping after pulmonary vein isolation. LVZ was defined as regions where bipolar peak-to-peak voltage was <0.5mV. We set 5 cm² as the cutoff of the presence of LVZ. The etiology of cardiomyopathy was divided into arrhythmia-induced cardiomyopathy (AICM) and non-AICM consisting of idiopathic dilated cardiomyopathy (iDCM), hypertrophic cardiomyopathy (HCM), ischemic cardiomyopathy (ICM), transthyretin amyloidosis wild type (ATTRwt) and others (1 Fabry disease, 1 cardiac sarcoidosis, 1 restrictive cardiomyopathy). AICM was defined as patient whose LVEF was recovered above 50% after maintenance of sinus rhythm. We investigated the proportion of LVZ by etiology, and the association between LVZ and the composite endpoint consisting of all cause death, heart failure hospitalization, ventricular assisting device implantation, ventricular arrhythmia and stroke. Results Out of 125 patients [age 68 (58-73), female 32 (25%), LVEF 34.0 (25-43)], 51 (41%) had LVZ. Sixty-four patients were AICM etiology (LVEF pre to post: 30.7±10.7% to 61.1±6.7% ) and 61 was Non-AICM etiology (LVEF: 40.7 ± 18.1 to 44.7±15.7, P=0.0062). The presence of LVZ was lower in AICM than in non-AICM group (20.3% vs. 62.3%, P<0.0001). The etiology of non-AICM was consisting of 26 iDCM, 18 HCM, 7 ICM, 7 ATRRwt and 3 other etiology. The prevalence of LVZ was lower in AICM than in non-AICM (20.3 vs. 62.3%, P<0.0001). Detail is shown in Figure 1. Next, the incidence of composite endpoint was higher in patients with LVZ than in those without (HR 4.6, 95%CI 2.1-10.0, P=0.0001) (Figure 2A). Among 4 groups stratified by AICM/non-AICM and with/without LVZ, there was significant difference in the incidence of the composite endpoint (Figure 2B, P<0.0001). After adjusted with age, gender, Non-AICM, LVZ, LVZ tended to have association with composite endpoint (2.21, 0.87-5.65, P=0.097) and Non-AICM showed strong association (5.58, 1.55-20.12, P=0.0086). LVZ was associated with HF hospitalization (4.35, 1.21-15.61, P=0.024). Conclusions The prevalence of LVZ was 60% in Non-AICM, while it was 20% in AICM. LVZ tended to be associated with poor prognosis of cardiomyopathy after AF ablation. LVZ was associated with HF hospitalization in patients with cardiomyopathy. LVZ might be the marker for poor prognosis in cardiomyopathy cohort.

Strategic timing- early and delayed catheter ablation in atrial fibrillation

Abstract Background Atrial fibrillation (AF) is the most common sustained arrhythmia. AF catheter ablation (CA) is superior to antiarrhythmic drug (AAD) therapy in maintaining sinus rhythm. However, not much is known regarding the optimal timing of the ablation. Purpose This review aims to examine the evidence supporting both early and delayed ablation approaches, as well as explore their respective disadvantages. Methods We performed an electronic search in databases such as PubMed, ScienceDirect, Springer, Wiley Online Library, focusing on studies published from 2013 until 2022 and including both observational studies and randomized controlled trials (RCTs). Left atrial diameter and ejection fraction (EF) were assessed. The limit between early and delayed ablation was set to be 3 years, considering delayed CA studies with a diagnosis-to-ablation-time (DAT) of 3 years or more, and early CA studies with a DAT of less than 3 years. Included studies were selected according to our eligibility criteria: observational studies or RCTs that included patients with symptomatic paroxysmal or persistent AF that underwent ablation using either radiofrequency or cryoballoon approach or both approaches, studies that reported DAT, studies that included a follow-up period, studies that evaluated AF recurrence or AF burden. Studies that included a surgical ablation, a hybrid ablation approach, or ablation for arrhythmias other than AF were excluded. Results Ten studies were selected out of 1387 identified records. After a follow-up period of 1 year, the early ablation subgroup had a lower mean AF recurrence rate (31.1%) compared to that of the delayed ablation subgroup (37.7%) ( p<0.0004). The median AF recurrence rate in radiofrequency ablation group was (47.8%) in comparison to the AF recurrence rate in cryoablation group which was (27.4%) (p<0.0001). In studies that included paroxysmal AF patients exclusively, the AF recurrence rate was directly proportional to the DAT(R=0.95). Conclusion Our results demonstrate that DAT correlates with recurrence rate at 1 year following AF CA, the shorter the DAT the better the outcome especially in paroxysmal AF population.Prisma study selection flow diagramCorrelation between DAT-AF recurrence

Left atrial appendage volume estimated by artificial intelligence predicts atrial fibrillation recurrence after cryobaloon ablation

Abstract Background/Introduction The volume of the left atrial appendage (LAA), as measured in contrast-enhanced cardiac computed tomography (CCTA), has been previously reported as a predictor of long-term recurrence of atrial fibrillation (AF) following cryoballoon ablation procedures. Unfortunately manual assessment of LAA volume, is tedious and time-consuming, making it impractical for clinical practice. The recent advent of artificial intelligence (AI)-based methods offers a potential solution to this limitation. Purpose This study aims to evaluate the utility of LAA volume, as automatically measured by a state-of-the-art AI model for the fully automatic segmentation of LAA in CCTA, in predicting AF recurrence following cryoballoon ablation procedures. Methods We retrospectively analyzed a cohort of patients who underwent cryoballoon ablation for pulmonary vein isolation at our facility between 2010 and 2016. AF recurrence was determined through in-person visits and Holter monitoring at 3, 6, and 12 months post-ablation, followed by annual visits. The first three months post-ablation were considered a blanking period. An open-source deep neural network AI model [1] was utilized to perform automatic segmentation and calculation of LAA and left atrium (LA) volumes in. Receiver-operating characteristic curves were used to obtain optimal cut-off values for increased LAA and LA volumes. We then assessed the association of increased LAA and LA volume, and the LAA to LA volume ratio with recurrence-free survival using the Cox regression model. Results The cohort consisted of 212 patients (median age 62, inter-quartile range [IQR]: 55–65), with 25% having persistent AF before the procedure. Subjects were observed for a median period of 12 months (IQR: 12–36), with 70 of them (33%) experiencing a documented recurrent AF episode. The optimal thresholds for predicting AF recurrence were established as 9.8ml for LAA volume, 124ml for LA volume, and 0.086 for the LAA to LA volume ratio, respectively. An increased LAA volume demonstrated the strongest association with AF recurrence (hazard ratio [HR]: 2.6, 95% confidence interval [CI]: 1.55–4.2), followed by an increased LA volume (HR: 2.1, 95% CI: 1.3–3.4), persistence of AF (HR: 2, 95% CI: 1.2–3.3), and increased LAA to LA volume ratio (HR: 1.9, 95% CI: 1.1–3). Kaplan-Meier plots illustrating AF-free survival, are presented in Figure 1. After adjusting for age, persistent AF, left ventricular ejection fraction, and body surface area, all AI measurements remained significantly associated with a higher AF recurrence (Table 1). Conclusions Increased LAA volume, as assessed automatically by AI in CCTA, is a useful predictor of AF recurrence after catheter ablation for atrial fibrillation. The use of freely available, AI-assisted analysis of CCTA could be instrumental in assessing LAA volume, among other predictors, for long-term ablation success.Figure 1.

Catheter ablation increases cerebral blood flow and cognitive function in elderly patients with atrial fibrillation

Abstract Background Atrial fibrillation (AF) has been considered to have an increased risk for cognitive impairment independent of a stroke and a silent micro-infarction. The mechanism of this interaction is unclear. One of the potential explanations is brain hypoperfusion due to a reduced cardiac output. To date, there are no reports focusing on the cerebral blood flow and cognitive impairment in patients undergoing AF ablation. Purpose The purpose of this study was to investigate whether catheter ablation of AF would increase cerebral blood flow and restore cognitive impairment. Methods AF patients aged 75 years or older with mild or more cognitive impairment were selected. The assessment of cognitive function using Mini-Mental State Examination (MMSE) and Hasegawa's Dementia Scale-Revised (HDS-R), and measurement of cerebral blood flow using 99mTc-ECD SPECT imaging were examined before and 3 months after ablation. Results A total of 25 elderly patients (mean age 83, 14 males and 11 females) were included in this study. Of them, 23 patients had persistent AF. Twenty-three patients (92%) maintained sinus rhythm after ablation. There was a significant improvement in MMSE score (from 24.6±4.5 to 25.9±4.0, p<0.05) and HDS-R (from 23.2±5.5 to 24.8±5.1, p<0.05) after ablation. Cerebral blood flow also significantly increased after ablation (right lobe: from 34.4±4.6 to 38.5±4.4 ml/100g/min, p<0.01, left lobe: from 35.3±9.7 to 38.8±3.7 ml/100g/min, p<0.01). Overall average cerebral blood flow increased by 10.1±9.4% after ablation. There was a positive correlation between the changes in MMSE score and the changes in cerebral blood flow (r=0.65, p<0.05). Conclusion AF ablation in elderly patients increased cerebral blood flow and cognitive function. AF ablation would be one of the therapeutic options to improve cognitive function in elderly patients with cognitive impairment.