Pulmonary Vein Research Articles

Characterization of sedation strategies in real-world use of pulsed field ablation: sub-analysis of the EU-PORIA registry

Abstract Background/Introduction With the introduction of pulsed field ablation (PFA) to treat patients with atrial fibrillation (AF), there has been interest in studying workflow and sedation strategies to better understand how this new technology can be integrated into clinical practice. Purpose Characterize the use of general anesthesia (GA) versus deep sedation during real-world use of the pentaspline PFA catheter to treat AF. Methods EU-PORIA is an all-comer AF registry enrolling consecutive patients treated with the pentaspline PFA catheter at seven high-volume centers in Europe. Patients were treated based on institutional standard of care. During follow-up, any episode of atrial tachycardia (AT) or AF lasting longer than 30 seconds was considered an arrhythmia recurrence. Results EU-PORIA enrolled 1233 patients, of which 250 ablation cases were performed under GA and 983 cases were performed with deep sedation. Six out of the 7 participating centers employed a single sedation strategy (2 GA; 4 deep sedation), with one center doing a mix of both sedation and GA. The patient population treated with GA had fewer female patients (30% vs 40%; p=0.04), a lower prevalence of hypertension (43% vs 57%; p<0.01), and fewer paroxysmal AF patients (54% vs 62%; p<0.01). The ablation strategy was performed based on operator’s discretion. In the GA group, 72% of patients received a pulmonary vein isolation (PVI)-only ablation approach versus 90% of patients in the sedation group (p<0.01). The most common additional lesion set performed was posterior wall isolation which accounted for 23% and 7% of cases in the GA and sedation groups, respectively (p<0.01). Procedure times and fluoroscopy times were significantly shorter in the sedation group versus the GA group (51 [36-84] min vs 75[60-90] min; 13 [8-19] min vs 19 [15-26] min; p<0.01 for both). Mapping was used in 60% of cases in the GA group versus only 26% of cases in the sedation group. Overall, there were no differences in the incidence of serious adverse events, and no difference in chronic treatment success. At 1-year follow-up, 74.8% of patients (187/250) in the GA group and 73.8% of patients (725/983) in the sedation group were free from recurrent AF/AT. Conclusion(s) In this registry, the use of deep sedation for AF ablation with the pentaspline PFA catheter demonstrated a safety and efficacy profile consistent with those procedures performed under GA. The majority of the deep sedation procedures were PVI-only and performed in a less progressed AF disease state. It is worth noting that there may be certain patient populations and center restrictions where GA will remain the necessary approach for AF ablation. This characterization of real-world use warrants further evaluation to understand optimal sedation strategies that can be used with PFA technologies.

Impact of obesity and early recurrence of atrial fibrillation on very late recurrence following cryoballoon pulmonary vein isolation

Abstract Background Obesity and early recurrence of atrial fibrillation (ERAF) post cryoballoon (CB) pulmonary vein isolation (PVI) both portend a lower 1-year success rate of ablation. Even after an initial successful ablation, about 1/3 of patients develop a very late recurrence (VLR) of AF, defined as the first AF recurrence more than a year after ablation (excluding an initial 90 day blanking period [BP]). The impact of obesity and ERAF on VLR is still unknown. Purpose To evaluate the impact of obesity and ERAF on VLR following CB PVI. Methods We enrolled consecutive patients with symptomatic AF who underwent CB PVI and had an implantable loop recorder for long-term ECG monitoring. We identified patients who had no AF recurrence (outside the BP) in the first-year post ablation. ERAF was defined as any episode of AF recorded in the first 90 days post ablation. Patients were grouped as either obese (BMI ≥ 30 kg/m2) or non-obese (BMI <30 kg/ m2). AF recurrences after 1-year post-ablation were ascertained using the loop recorder. Results From the initial cohort of 210 patients, 109 (52%) patients (64 ± 10 years; 75 [68%] male; 64 [59%] PAF; CHA2DS2-VASc 2.3 ± 1.4, 38 [35%] with obesity and 41 [38%] had ERAF) were AF-free during the first year. During a follow-up of 961 ± 196 days, 51 (47%) patients had VLR. Non-obese patients without ERAF had the best outcome (Figure). In multivariate analysis, obesity and ERAF were the only significant predictors of VLR (Table). As compared to non-obese patients without ERAF, obese patients with ERAF had a 4-fold greater likelihood of VLR. Conclusions About 50% of patients have no AF recurrence in the first year after CB PVI. Non-obese patients have the best outcome regardless of ERAF occurrence. On the other hand, obese patients with ERAF almost always have VLR.

Risk and management of acute kidney injury resulting from hemoglobinuria following pulsed-field ablation in atrial fibrillation

Abstract Background High-voltage pulses can cause hemolysis leading to hemoglobinuria. Purpose We evaluated the prevalence of hemoglobinuria after pulsed-field ablation (PFA) and its impact on renal function in patients with atrial fibrillation (AF). Methods A consecutive series of 128 AF patients undergoing PFA were included in this analysis. The initial patients that did not receive post-ablation hydration were classified as group 1 (n=28) and the rest of the study population that received planned fluid infusion of ≥2 L after the procedure, were categorized as group 2 (n=100). Patients with estimated glomerular filtration rate (eGFR) <45 were excluded. All underwent extensive ablation beyond pulmonary vein isolation. If urine tested positive for hemoglobin, blood samples were tested for Haptoglobin. Results Baseline characteristics of the study population are provided in Table 1. Number of overall PFA applications were comparable between groups (group 1: 52.07±23.99 vs group 2: 59.83±22.78, p=0.149). Four patients in group 1 received 94.63±3.20 PFA applications. In group 2, 4 patients received >90 applications (94±2.82) and 2 patients received >150 (158.5±4.95) PFA applications. Of the 28 in group 1, 21 (75%) developed hemoglobinuria during the 24-hour following catheter ablation. Mean post-ablation S-Cr was significantly higher than the baseline value in these 21 patients (1.46±0.28 vs 0.86±0.24, p <0.001). Of the 21, 4 (19%) patients that received a mean of 94.63±3.20 PFA applications had the S-Cr. >2.5 mg/dL (mean: 2.95±0.21). These 4 patients were also markedly oliguric (<400 ml/day) in the immediate post-ablation period. Group 2 patients received significantly higher amount of fluid infusion following catheter ablation compared to group 1 (2092.53±198.94 vs 487.48±72.74 ml, p<0.001). None of the 100 patients from group 2 developed detectable hemoglobinuria or elevation of S-Cr including the 4 patients with >90 and 2 patients with >150 PFA applications. Mean post-ablation Haptoglobin was 10.00± 8.40 (normal: 36–195 mg/dL). The accuracy of number of applications predicting Haptoglobin decline was excellent with the area-under the curve (AUC) 0.886 ± 0.068 with 95% CI of 0.754 – 1.000. (P-value = 0.002). In multivariable analysis, both hydration (R-square 0.34, p <0.01) and number of PFA applications (R-square 0.40, p <0.038) were independent predictors of post-procedure acute kidney injury. Conclusions Based on our findings, number of PFA applications was an independent predictor of renal insult in patients receiving extensive ablation that could be prevented using planned fluid infusion immediately after the procedure.

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

CILP1 and NTproBNP in pulmonary hypertension and right ventricular pressure overload: a translational experimental study

Abstract Introduction Cartilage intermediate layer protein 1 (CILP1) has emerged as a novel marker of right ventricular (RV) dysfunction in pulmonary hypertension (PH), although there is still little evidence on its role in different scenarios of RV pressure overload. The aim of our study was to analyze CILP1 as a biomarker of RV remodeling and PH severity, and compare it with N-terminal pro-brain natriuretic peptide (NTproBNP), in different experimental models of RV pressure overload. Methods Three different experimental models of RV pressure overload compared to a sham procedure were evaluated in 24 Yucatan pigs: chronic postcapillary PH by pulmonary vein banding (M1, n=6); chronic PH by aorto-pulmonary shunting (M2, n=6); RV pressure overload by PA banding (thus without PH) (M3, n=6); and sham procedure (M0, n=6). Animals were evaluated at 8 months after surgery by right heart catheterization, cardiac magnetic resonance (CMR), and blood/histological sampling. Levels of CILP1 and NTproBNP at the RV myocardium and blood were determined with dedicated ELISA and compared among groups by Wilcoxon test with Bonferroni correction. Associations between biomarkers and RV performance indices and pulmonary arterial pressure (PAP) were assessed with Spearman correlation test. Results M1 animals developed chronic postcapillary PH with normal left ventricular (LV) performance and RV maladaptive hypertrophy (RV fibrosis and systolic dysfunction). M2 animals developed chronic precapillary PH associated with LV dilatation and RV maladaptive hypertrophy. On contrast, M3-animals developed severe RV pressure overload (without PH) and hypertrophy but maintained normal RV systolic function. CILP1 and NTproBNP levels were moderately correlated (R=0.56, p=0.002). CILP1 levels in RV myocardium and plasma were significantly higher in M1, whereas NTproBNP plasma levels were significantly higher in M2 (Figure 1). CILP1 in plasma and RV myocardium significantly correlated with PAP, while myocardial CILP1 levels also correlated with RV extracellular volume (RV-ECV) by CMR (Figure 2). NTproBNP myocardial levels correlated with RV ejection fraction and RV-ECV and plasmatic levels correlated with PAP (Figure 2). Conclusions CILP1 levels were increased in the presence of PH and isolated RV dysfunction, whereas NTproBNP levels were increased in the model of PH, RV dysfunction and LV remodeling. Myocardial levels of both peptides correlated with diffuse fibrosis, estimated by CMR, whereas plasmatic levels of both biomarkers correlated with PAP. This suggests that CILP1 may be a more specific marker of RV dysfunction in PH, being less dependent of LV parameters.CILP1 and NTproBNP levels among modelsCorrelation with PAP & RV remodeling

Ppulsed field ablation and ultra-high-density mapping for PVI: use of machine learning and data augmentation to guide procedure and identify recurrent tachycardia mechanisms at one-year follow-up

Abstract Background In managing atrial fibrillation (AF), radiofrequency and cryoablation have been cornerstone techniques for achieving pulmonary vein isolation (PVI). Recently, pulsed-field ablation (PFA) has introduced a novel method for PVI. There remains a gap in knowledge regarding the permanent efficacy of ablation, related explicitly to acute lesion characteristics following PVI. Purpose Our study delves into an in-depth examination of acute lesion characteristics following PFA-PVI through ultra-high-density mapping (UHDM). We aim to identify specific clinical, anatomical, and periprocedural lesion features independently related to 1) intraoperative identification of UHDM non-isolated gaps with electrical conduction after first isolation and 2) three months follow-up recurrency of specific arrhythmias. Methods Results The present study includes 204 patients submitted to PFA-PVI for AF. UHDM guided all procedures to identify non-isolated gaps with electrical conduction. Perioperative and 3-month follow-up data were collected prospectively and analyzed. To build our prediction model, avoiding biases related to the unbalanced nature of the data, data augmentation was performed with SMOTE (Synthetic Minority Over-sampling Technique). Two machine learning (ML) models have been built, using logistic regression as learner, to predict the presence of isolation gaps identified by UHDM and follow-up recurrence of arrhythmias. A 20-fold cross-validation has been performed to train and test the models. The non-isolated gap was detected and immediately corrected in 14 (6.9%) patients and was present more often in patients with larger left atria (LA) (p<0.0001) and those with persistent AF (p=0.02). The ML model achieved an AUC of 0.88 in the prediction of the non-isolated gap after PFA (Precision: 0.65; Sens.: 0.90; F1: 0.76; Spec.: 0.83; NPV: 0.96). At three months follow-up, no patient experienced recurrent AF; recurrent roof-dependent atrial tachycardia was present in 10 (4.9%). Patients with recurrent atrial tachycardia had a significantly narrower remaining atrial-roof conduction bridge (p=0.01) identified intra-procedurally by UHDM, significantly larger LA (p=0.03), and non-significant trend for older age (p=0.07). The ML model achieved an AUC of 0.86, predicting recurrent tachycardia after PFA (Precision: 0.63; Sens.: 0.86; F1: 0.72; Spec.: 0.82; NPV: 0.94). Conclusions Consistent use of UHDM can help identify non-isolated gaps with electrical conduction that may occur even after PVI with updated technologies, such as PFA. Non-isolated gaps should be expected, particularly in patients with larger LA, where UHDM could be of particular use. Moreover, UHDM can help predict the eventual recurrence of arrhythmias. Again, LA size plays an essential role in such recurrencies, together with the size of the remaining conducting tissue "bridges" within the LA roof, measure by UHDM.

Atrial fibrillation recurrence rates in patients with transthyretin cardiac amyloidosis undergoing pulmonary vein isolation: a comparative retrospective study with propensity score matching

Abstract Background Atrial fibrillation (AF) affects up to 70% of individuals diagnosed with transthyretin cardiac amyloidosis (ATTR CA) [1]. AF ablation is frequently considered in the management of these patients, but there is a lack of data about outcomes of the procedure in this population. Purpose This study aims to evaluate AF recurrence rates and long-term AF recurrence-free survival in patients with ATTR CA undergoing pulmonary vein isolation (PVI). Methods A single-center retrospective study was conducted, including all patients diagnosed with ATTR CA who underwent PVI from 2016 to 2023. We compared patients with amyloidosis (cases) to those without (controls), employing propensity score matching for age, gender, AF type (paroxysmal vs. persistent), BMI, diabetes, arterial hypertension diagnosis, antiarrhythmic drug therapy post-index ablation, and left atrium (LA) volume assessed by 3D rotational angiography (3DRA). Results 16 patients with CA were matched to 16 patients without (32 patients in total). After matching, the populations demonstrated comparable baseline characteristics (figure 1). The study consistently revealed a higher AF recurrence rate, after PVI, in the CA group (81.3%) compared to the control group (37.5%) at the last follow-up (p-value 0.01) (median follow-up 1255 ± 1055 days in CA and 1491 ± 464 days in control group), as well as a significantly lower long-term AF-recurrence free survival (log-rank p = 0.01 – figure 2). Additionally, the recurrence rate at 1-year post-procedure was 56.25% in the CA group and 18.75% in the control group (p-value 0.03). Conclusions Pulmonary vein isolation remains a viable treatment option for individuals with ATTR CA. However, it proved less effective (or less durable) than in the general population without the disease, both at 1-year follow-up and for longer periods, as shown also with recurrence-free survival rate. Further studies are warranted to determine the optimal treatment strategy for this specific population.Baseline Characteristics fig. 1Kaplan Meyer fig. 2

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

Atrial pace mapping with automatic intracardiac pattern matching for non-pulmonary vein trigger ablation: accuracy and feasibility

Abstract Atrial pace mapping (APM) is an alternative method to localize non-pulmonary vein (non-PV) triggers of atrial fibrillation(AF) that are otherwise not eligible for activation mapping due to their instability. The technique applies pattern matching of p-waves and intracardiac signals of atrial trigger and pacing from the site of the suspected origin. A new automated algorithm for intracardiac (IC) pattern matching was recently introduced into the 3D mapping system using the unipolar signal of the reference catheter. The study aims to assess the accuracy and feasibility of APM using IC-pattern matching for localizing non-PV triggers. Methods We assessed the precision of APM using a single chamber and double chamber reference in 20 patients who underwent index pulmonary vein isolation. APM was performed at the anterior and posterior wall of the left atrium (LApost, Laant) and the posterior and lateral wall of the right atrium (Rapost, Ralat). The first pacing point was declared as the origin. The IC-pattern matching algorithm was applied to calculate the similarity of the IC-pattern of the origin to the paced IC-pattern across various distances. The distribution of IC-pattern similarities was analyzed in the Python environment. The feasibility of APM was tested in patients who underwent REDO ablation of AF if all PVs were isolated and no low-voltage substrate was detected. The induction protocol for non-PV triggers included programmed and burst atrial pacing, high-dose isoproterenol, and adenosine infusion. If the IC pattern of the trigger was reproducible, the IC pattern matching was conducted. Ablation was performed at the site of the best IC-pattern matching. Results Atrial PM with IC-pattern matching and a single referent catheter showed lower precision in the RA lateral region (the median[Q1; Q3 ]area of 5% best matching score 1.48 [0.76; 2.01], 0.62[0.15; 1.06], 0.6[0.38; 1.19] and 5.68[2.89; 11.1] cm2 for LApost, LAant, RApost, RAlat accordingly, p = 0.0316). IC-pattern matching with double referent catheter showed high precision at all four anatomical regions (the median [Q1; Q3] area of 5% best matching score 0.126 [0.0879; 0.356], 0.486 [0.205; 0.717], 0.269 [0.198; 0.719], and 0.257 [0.0740; 0.572] cm2 for LApost, LAant, RApost, RAlat accordingly, Fig. 1). Seven out of 37 patients referred to REDO ablation had all PV isolated and absence of low-voltage substrate. In 3 of them, sustained tachycardias (AVNRT, focal atrial tachycardia and typical atrial flutter) were induced, mapped, and ablated. Non-sustained FAT from the RA posterior wall and PAC in the RA septum were induced under the high-dose isoproterenol infusion in two patients. Atrial pace mapping with double chamber referent and successful ablation of these non-PV triggers were performed (Fig.2). Conclusion The atrial pace mapping of non-PV triggers employing the automatic intracardiac pace mapping algorithm is feasible with high accuracy if a double-chamber referent is used.Accuracy of atrial pace mappingNon-PV trigger pace mapping

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

Comparison of continuity index for drag versus point-by-point ablation with the use of proactive esophageal cooling

Abstract Background Proactive esophageal cooling was recently FDA cleared to reduce the likelihood of esophageal injury during radiofrequency (RF) ablation for treatment of atrial fibrillation (AF). Long-term follow-up data have also shown improved freedom from arrhythmia with proactive esophageal cooling compared to luminal esophageal temperature (LET) monitoring during pulmonary vein isolation (PVI). One hypothesized mechanism is the greater lesion continuity attainable with the use of cooling, which can be quantified by the Continuity Index (which increases as continuity decreases). Increasing the Continuity Index increases gap formation, reduces isolation, and leads to greater AF recurrence; however, the difference in Continuity Index between ablating in a point-by-point fashion versus a dragging fashion has not previously been analyzed. Purpose To prospectively measure the Continuity Index of PVI cases and compare the dragging technique to point-by-point technique when using proactive esophageal cooling or LET monitoring. Methods We determined the Continuity Index for 101 patients: 77 prospectively utilizing proactive esophageal cooling, 24 retrospectively recorded using LET monitoring. Cases were completed by four operators, three utilizing point-by-point technique, and one using the drag technique. The Continuity Index was calculated by incrementing one unit for each lesion that did not border the previous lesion during the PVI (simplifying the original description of the Continuity Index). Results For cases using esophageal cooling and performing RF ablation using the drag technique, the average Continuity Index was 8.5 (range: 1 to 14). For point-by-point operators using esophageal cooling, the average Continuity Index was 1.2 (range: 0 to 9), representing a difference of 7.3 between the dragging technique and point-by-point ablation (p < .001). Patients receiving LET monitoring and RF ablation using the drag technique had Continuity Indices of 23.8 (range 15 to 30). Patients receiving LET monitoring and RF ablation using point-by-point ablation had Continuity Indices of 28.4 (range 16 to 50). Figure 1 compares these findings. Only 4 patients (5%) in the esophageal cooling group had a Continuity Index above 6 on either side (all in the dragging group), versus 100% (24) of patients in the LET monitoring group. Conclusion Proactive esophageal cooling during PVI is associated with a high degree of lesion continuity, as represented by the low Continuity Index. The drag technique resulted in a higher index than the point-by-point technique, but both provided significantly lower Continuity Indices (greater lesion continuity) than cases using LET monitoring. This may offer a mechanism for the greater freedom from arrhythmia seen to date with proactive cooling in long-term follow-up.Figure 1.Comparison of Continuity Index

Long-term prognosis in patients undergoing atrial fibrillation ablation

Abstract Aims The aim of the analysis was to assess the risk of atrial fibrillation (AF) recurrence in the long-term observation of contemporary patients undergoing pulmonary vein isolation (PVI), who did not have recurrence during the first year after catheter ablation. Methods Retrospective analysis has been performed. Inclusion criteria: (1) the patients undergoing their first PVI in years 2017–2022, (2) the electroanatomical system, contact force catheters and lesion indexes (Ablation Index or Lesion Size Index) were used, (3) no recurrences were observed during the first 12 months of follow-up, and (4) follow-up longer than 12 months was available. Demographic, clinical and echocardiographic data were collected. Follow-up was based on ambulatory visits with ECG/holter monitoring or implanted device interrogation, when available. Results A total of 247 patients were included. The median follow-up was 22 months (interquartile range, 16–31 months). After 24 months, ablation efficacy was 84%, and after 36 months, it was 72%. In the univariate Cox regression analysis, age, previous electrical cardioversion, glomerular filtration rate (eGFR) and the presence of coronary artery disease were linked to AF-free survival. Interestingly, nonparoxysmal AF, left atrial (LA) dimension, heart failure, hypertension or diabetes were not linked to the risk of long-term recurrences. In multivariate Cox regression analysis, presence of coronary artery disease and previous electrical cardioversion were independently linked to the risk of long-term recurrence. In 127 (51.4%) patients, information about the presence of low voltage areas (LVA) was available, and in 21 (16.5%) patients in this group, the presence of LVA was found. Survival of patients with LVA was strikingly worse than that of those without (Figure 1), log-rank test p <0.0001. Conclusions Patients who had no recurrences within one year after PVI, still have substantial risk of recurrence in the next 2 years. That concerns specially the patients who had LVA in the electroanatomical mapping.

Weight change does not impact long-term outcomes following cryoballoon pulmonary vein isolation

Abstract Background Weight loss has been suggested to reduce frequency and burden of atrial fibrillation (AF) in overweight patients (pts). However, there are limited data on weight loss impact on outcomes in pts with AF who have undergone pulmonary vein isolation (PVI). Purpose To understand the impact of weight change on long-term outcomes, as assessed by freedom from recurrent AF in pts undergoing cryoballoon (CB) PVI. Methods We enrolled consecutive pts with AF who underwent CB PVI; all had implantable loop recorders (ILR) for long-term ECG monitoring. The cohort was divided into 4 groups based on weight change 1-year post ablation: (1) optimal weight loss (OWL) – weight decrease ≥ 10%; (2) minimal weight loss (MWL) - weight loss (WL) 3-9% weight decrease; (3) no weight change (NWC) - weight change < 3%, (4) weight gain (WG) ≥ 3% weight increase. We assessed for AF recurrence after excluding a 3-month post-ablation blanking period. Results Out of a total of 322 pts who underwent ablation, 241 (75%) pts (69 ± 10 years; 159 (66%) male; 133 (55%) PAF; CHA2DS2-VASc 2.7 ± 1.5; BMI 30 ± 5) had weight information available at ablation and last follow-up. All were off antiarrhythmics by 1 year. There were no differences in the 4 cohorts with respect to baseline characteristics. During the first year, about ¼ of pts were able to lose ≥ 3% of weight but only 8 pts (3%) were able to lose ≥ 10%. AF recurred in 153 (63%); they were older, more likely to have persistent AF (PeAF), and a higher CHA2DS2-VASc score. However, weight change did not impact outcome (Figure). In a multivariate Cox Regression hazards analysis, PAF vs. PeAF at ablation was the only factor associated with any recurrence at follow-up (Figure). Conclusions Post CB PVI only about ¼ of pts are able to lose weight. Weight changes in the first-year post ablation in obese pts did not alter outcomes with respect to likelihood of recurrent AF. These data should be taken into account when considering catheter ablation.

Comparison of procedural analgosedation in patients undergoing pulsed field ablation or cryoballoon ablation for atrial fibrillation

Abstract Background Pulsed field ablation (PFA) has emerged as a novel technology that is increasingly applied for the catheter ablation (CA) of atrial fibrillation (AF) with similar efficacy to established, thermal energy sources. Data solely focussing on analgosedation compared to established single-shot modalities, such as cryoballoon (CB) ablation are scarce. Aim The aim of this study was to assess differences of analgosedation requirement, procedural cardiopulmonary stability, and analgosedation-associated complications between PFA and CB ablation. Methods This study was a retrospective single-centre comparison of analgosedation in patients with paroxysmal, persistent, and long-standing persistent AF undergoing pulmonary vein isolation (PVI) with either PFA or CB from March 2021 until April 2022. The primary study endpoints were the requirements of analgosedation medications (propofol, midazolam and sufentanyl), cardiorespiratory stability measured as decreases in oxygen saturation and systolic blood pressure and analgosedation-associated complications. Secondary endpoints were acute procedural success, procedure time and overall complication rates. Results A total of 100 patients were included {PFA n=50, CB n=50, mean age 66 ± 10.6, 61% male patients, 65% paroxysmal AF). The body weight – and procedure time-adjusted requirement of all analgosedation medications was significantly higher in the PFA group compared to CB {Propofol 0.14 ± 0.04 mg/kg/min in PFA versus 0.11 ± 0.04 mg/kg/min in CB (p=0.001); midazolam 0.00086 ± 0.0004 mg/kg/min in PFA versus 0.00063 ± 0.0003 mg/kg/min in CB (p=0.002) and sufentanyl 0.0013 ± 0.0007 µg/kg/min in PFA versus 0.0008 ± 0.0004 µg/kg/min in CB (p<0.0001)}. Procedural cardiorespiratory stability did not differ between groups (maximum blood pressure decrease PFA 53.4 ± 20.9 mmHg, CB 50.3 ± 18.6 mmHg, P=0.28 and maximum decrease in oxygen saturation: PFA group 4.8 ± 5.3 %, CB group 3.5 ± 2.6 %, P=0.12). Analgosedation-associated complications did not differ between both groups (PFA n=1/50 mild aspiration pneumonia, CB n=0/50, p=0.99). There was no significant difference in acute procedural success (100% n=50/50 in both groups, p>0.99), non-analgosedation associated complications (PFA: n=2/50, 4%, CB: n=1/50, 2%, p=0.99) and procedure times (PFA 75 ± 31, CB 84 ± 32 mins, p=0.18) between groups. Conclusions Pulsed field ablation is associated with higher sedation and especially analgesia requirement compared to cryoballoon ablation, however, the safety of analgosedation does not differ significantly to cryoballoon ablation.

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

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.

Significant reduction of complications applying an optimized vascular access and post-interventional groin-site management during electrophysiology procedures

Abstract Background Catheter ablation of cardiac arrhythmias is an established treatment strategy. However, the optimal femoral vascular access strategy and post-interventional management in the electrophysiology (EP) setting is still under debate. Purpose To assess the impact of ultrasound-guided versus conventional femoral vascular puncture and of a modified post-interventional groin-site management strategy on complication rates. Method Patients undergoing EP procedures at the our university heart and vascular center are included in an institutional prospective registry. Conventional vascular access as well as post-interventional groin site pressure-bandage and bed rest of 6 hours (group I) was compared to a new strategy including ultrasound-guided vascular access, venous closure by a Z-suture and groin site pressure-bandage for only 2 hours plus additional 4 hours bed rest (group II). Incidences of minor and major groin site complications for both groups were compared. Hematoma, bleeding, arteriovenous fistula or pseudoaneurysm of the femoral artery without need for intervention (e.g. transfusion, thrombin injection, surgery) were classified as minor complications. Complications requiring intervention or retroperitoneal hematoma were defined as major complications. Results A total of 1535 procedures in 1381 patients (779 (51 %) procedures in 705 (51%) patients in group I and 756 (49%) procedures in 676 (49%) patients in group II) were analyzed. In group I and group II, respectively, 39%/44% procedures were index pulmonary vein isolations, 30%/29% repeat atrial fibrillation, 16 %/15% supraventricular tachycardia, 12%/11% PVC or VT ablations, and 4%/2% left atrial appendage occlusions. The total groin site complication rate was 9% (70/779 procedures) for group I, and 5% (38/756 procedures) for group II (OR 0.54 [95%-CI 0.35-0.82], p=0.003). Major groin site complications occurred in 2% (19/779 procedures) in group I and were reduced to 1% (10/756 procedures) in group II (OR 0.53 [95%-CI 0.22-1.22], p=0.156). Conclusion The overall groin site complication rate in EP-procedures was significantly reduced by implementing a novel institutional standard for vascular access management including ultrasound-guided puncture and a modified post-interventional groin site management.

The impact of body mass index for atrial fibrillation ablation; real-world data on outcomes and quality of life

Abstract Background Pulmonary vein isolation (PVI) is a cornerstone in the management of atrial fibrillation (AF). Increasing numbers of overweight and obese patients undergo PVI, despite the association between a higher body mass index (BMI) and adverse ablation outcomes. The risks of perioperative complications and quality of life have hardly been studied for the different bodyweight groups. Purpose The purpose of this study is to clarify the impact of BMI on PVI outcomes, including both perioperative complications and change in quality of life after PVI. Methods This is an observational, multicentre cohort study of prospectively collected data, covering all 15 ablation centres in the Netherlands. The study included all patients who underwent their first catheter-PVI between January 2015 and December 2021. Patients with a BMI below 18.5 kg/m2, missing BMI data, or prior ablations were excluded. Patients were categorized by BMI; normal weight (BMI 18.5-24.9 kg/m2), overweight (BMI 25-29.9 kg/m2) and obesity (BMI ≥30 kg/m2). The primary outcome was repeat ablation within one year. A logistic regression model was used to adjust for patient characteristics. A generalized additive model was fitted to visualize the correlation between BMI and the risk of repeat ablation. Secondary outcomes were repeat ablation within 3 years, a composite of the periprocedural complications, and change in quality of life, assessed using the Atrial Fibrillation Effect on QualiTy-of-Life (AFEQT) questionnaire before and at one year after PVI. Results A total of 20,725 patients (33% female) were included; 72% had a paroxysmal AF pattern. Of all patients, 30% were normal weight, 47% overweight and 23% obese. Within the first year post-index PVI, obese patients had a higher incidence of repeat ablation than normal-weighing and overweight patients (17.8% versus 15.6% and 16.1%, P <0.05). Obesity independently predicted an increased risk of repeat ablation within 1 year (odds ratio 1.15; 95%-confidence interval 1.01-1.31, P =0.03). This increased risk was also apparent for repeat ablations within 3 years (hazards ratio 1.15; 95%-confidence interval 1.06-1.25; P <0.01). The composite complication rate was 3.8% in normal weighing, 3.0% in overweight, and 4.6% in obese patients, with weight class not being an independent predictor. All weight groups had a substantial improvement in quality of life one year after ablation. Post PVI, summarized AFEQT score was still lower in obese patients (81), than in normal weight (88; P <0.01) and overweight patients (88; P <0.01). Conclusions In a nation-wide contemporary cohort, obesity is an independent predictor for undergoing a repeat ablation within both 1 and 3 years. This relation is not apparent for overweight individuals. Catheter ablation can safely be performed in all weight classes. Despite an overall lower quality of life among obese individuals, substantial improvements in quality of life occur in all weight groups.Visual abstract

Prediction of atrial fibrillation recurrence after ablation: the impact of machine learning and recurrence during the blanking period

Abstract Introduction Pulmonary vein isolation is superior to antiarrhythmic drugs for rhythm control in patients with atrial fibrillation (AF). Nevertheless, recurrences within the first year are still significant. Several clinical risk scores were developed to predict AF recurrence; however, despite good results in development cohorts, the results in external validation are usually poor, limiting the general applicability of these scores. Purpose We aimed to develop machine learning (ML) models to predict AF recurrences within the first year after catheter ablation and compare their performance with conventional risk scores. Methods We used a retrospective dataset of a tertiary hospital center, including all consecutive patients submitted to the first AF ablation between 2017 and 2021. The dataset included 76 features: patient characteristics, medical history, baseline echocardiography, calcium score, procedure variables, and early recurrence (ER) during the 90-day blanking period. The outcome was defined as the occurrence of an electrocardiographically documented late recurrence (LR) of atrial tachycardia/AF > 30s between 3-12 months. Three different supervised ML models (penalized logistic regression, random forests, and XGBoost) were developed on the training cohort, and hyperparameters were tuned using 10-fold cross-validation. A testing dataset was held out to estimate the final performance (25%). The following risk scores were calculated: APPLE, CAAP-AF, and BASE-AF2 (the last includes ER). Areas under the curve (AUC) of receiver operating characteristic curves were compared using DeLong’s test. Results 679 patients were included: 62.7% males, median age of 59±16 years, and 78.2% with paroxysmal AF. The median time from diagnosis to ablation was 2±4 years. 74.2% underwent radiofrequency ablation and the remaining cryoablation. ER occurred in 12.5%, and most of these patients also experienced LR (68.7 vs 19.6% in those without ER, p<0.001). LR was observed in 25.6%. The XGBoost model showed the best performance with an AUC 0.774, 95% confidence interval (CI) 0.688–0.844) outperforming existing scores (picture 1): APPLE score AUC 0.607, 95% CI 0.562–0.653, p-value<0.001; CAAP-AF score AUC 0.622, 95% CI 0.576–0.668, p-value=0.002; BASE-AF2 AUC 0.628, 95% CI 0.581–0.675, p-value= 0.003. Variable importance analysis showed a significant drop in the performance of the models when ER was not considered, indicating its high importance in predicting LR (picture 2). Conclusions Recurrence during the blanking period was the most important predictor of LR in our population. The ML model was superior to conventional risk scores. ML models might be an essential tool to improve the prediction of outcomes and clinical decision-making for optimal follow-up.ROC curvesFeature Importance

Utilizing cluster analysis of biomarkers alongside echocardiographic deformation parameters to forecast the outcome of atrial fibrillation post-ablation

Abstract Background Atrial fibrillation (AF) management often involves catheter ablation, but its recurrence necessitates careful clinical management and potential adjustments in medication or further ablation procedures. This study aims to investigate the predictive value of biomarkers and echocardiographic parameters for early AF recurrence. Methods In the prospective study, we enrolled patients with symptomatic paroxysmal or persistent atrial fibrillation undergoing catheter ablation. Pulmonary vein isolation was performed in every index procedure, with additional ablation or substrate modification as per physician preference. Blood samples were collected from both the atrium and peripheral vein to assess levels of tumor endothelial marker 1 (TEM1), galectin 3, connective tissue growth factor (CTGF), transforming growth factor-beta (TGF-β), C-terminal propeptide of procollagen type I (PICP), and Smad3. Pre-procedural echocardiographic parameters, including the E/e’ ratio, peak atrial longitudinal strain (PALS), and peak atrial contractile strain (PACS), were recorded. Clustering models with sparse canonical association analysis (CCA) were employed to develop predictive models integrating biomarker and echocardiographic data for early atrial fibrillation recurrence. Results Out of 80 prospectively enrolled patients, 68 completed the study, with six cases of early atrial fibrillation recurrence observed. Following dimension reduction and clustering, we found that the combined use of biomarkers and echocardiography significantly predicted atrial fibrillation recurrence (HR: 9.44, p=0.05, 95% CI: 1.0-88.9). Notably, among these parameters, TEM1 biomarker sampled from the peripheral vein (p=0.02), left atrium dimension (p=0.07), and left ventricle dimension (p=0.02) exhibited the most significant predictive power. Conclusions Our study highlights the effectiveness of integrating biomarkers and echocardiography parameters in predicting early recurrence of atrial fibrillation post-ablation in patients undergoing catheter ablation.main_figure