bluuebunny/crossref_metadata_2025 huggingface dataset:
Pulsed-field ablation using a lattice-tip catheter without general anesthesia is feasible for atrial fibrillation ablation
Authors: Hirokami J , Schmidt B , Bordignon S , Tohoku S , Chen S , Schaack D , Urbanek L , Ebrahimi R , Plank K , Chun J
Published: May 2024

Background

General anesthesia (GA) was employed to titrate lesion formations for a pulsed-field ablation (PFA) using a lattice-tip catheter. The evidence using a lattice-tip catheter without the use of GA is limited.

Purpose

We conducted a series of exploratory evaluation of a lattice-tip PFA catheter ablation without GA.

Methods

Patients undergoing their first atrial fibrillation (AF) ablation procedures using a lattice-tip catheter were enrolled in the study. To assess acute outcomes and safety, the patients were divided into two groups: one undergoing the procedure with GA and the other without GA. Procedural characteristics were collected.

Results

In total, 20 patients (6 with GA, 14 without GA) were enrolled in the current study. One patient in non-GA group needed a larynx mask due to apnea from anesthesia. The pre-ablation 3D mapping time was equivalent between the two group (with GA versus without GA: 17±7 versus 16±5; P=0.762). All first-pass isolations of the pulmonary veins (PV) were successfully achieved, and there was no difference in the number of applications between the right and left PV (with GA versus without GA: 45±8 versus 53±12; P=0.206 and 47±14 versus 49±9; P=0.792). Linear lesions including anterior linear ablation (33% with GA and 36% without GA: P=1.000), roof linear ablation (67% with GA and 71% without GA: P=1.000) and cavo-tricuspid isthmus ablation (0% with GA and 7% without GA: P=1.000) were performed. The ablation, laboratory stay and fluoroscopy times were equivalent between the two group (with GA versus without GA:88±22 versus 97±20; P=0.483, 128±25 versus 111±18; P=0.216 and 9±4 versus 10±2; P=0.902), while the pre-ablation preparation times were shorter in the group without GA (with GA versus without GA:40±17 versus 14±4; P<0.01). There was no major and minor procedural complication in both groups.

Conclusions

The use of a lattice-tip catheter for ablation without GA has a potential to shorten the whole procedural work-flow including preparing time while maintaining comparable safety and lesion formation to cases where GA is utilized.
Effectiveness of cryoballoon ablation for atrial fibrillation in patients with left common pulmonary vein variant: insights from a national multicenter catheter ablation registry
Authors: Elias A , Eyal A , Beinart R , Nof E , Michowitz Y , Glikson M , Konstantino Y , Haim M , Luria D , Omelchenko A , Marai I , Laish-Farkash A , Suleiman M
Published: May 2024

Background

Pulmonary vein isolation (PVI) is the most effective therapy to achieve rhythm control in atrial fibrillation (AF). Yet, data regarding the safety and effectiveness of this procedure in left common pulmonary vein (LCPV) variant is limited.

Purpose

To explore the effectiveness of cryoballoon AF ablation in patients with LCPV variant.

Methods

A prospective cohort, based on a multicenter registry that included patients who underwent PVI during the years 2019-2021. The study end points were acute isolation success of the pulmonary veins (PVs), AF recurrence and the need for a repeat ablation procedure at 12 months.

Results

Seventy-four patients with LCPV variant and 822 patients with standard four pulmonary veins (PVs) were included in the study cohort. The acute isolation success rates of the left pulmonary veins were significantly lower in the LCPV variants compared to the standard 2 left PVs; 95.9% versus 98.9% respectively (P=0.03). The acute isolation success rates of the right pulmonary veins were not different among patients with LCPV versus standard anatomy; 98.6% versus 98.5% respectively (P=0.9).

The rates of AF recurrence at 12 months were numerically higher in the LCPV variant compared to the standard anatomy group; 17.6% versus 11.1% respectively, but did not reach statistical significance (P=0.09) (Figure 1). The rates of repeat ablation did not differ between the study groups; 8.1% versus 6.2% respectively (P=0.51) (Figure 2).

Conclusion

In our study cohort, the acute isolation success rate of the LCPV was significantly lower compared to standard two left PVs, this finding emphasizes the challenge of isolating LCPV variants using cryoballoon PVI. However, in spite of the lower isolation success rates in the LCPV variants, the clinical effectiveness to prevent AF recurrences was preserved.Figure 1Figure 2
Adding 3D electroanatomical mapping to cryoballoon pulmonary vein isolation improves pulmonary vein isolation durability at repeat ablation procedure
Authors: Tijskens M , Abugattas J P , Wolf M , Schwagten B , De Greef Y
Published: May 2024

Objectives

The addition of pre- and post-ablation electroanatomical mapping with the Achieve catheter and EnSite mapping system has shown to improve acute pulmonary vein isolation (PVI) rate of cryoballoon ablation (CBA). Recently, our group also demonstrated an improvement in 1-year outcome. Current study aimed to investigate the impact on PVI durability as seen during repeat ablation procedure.

Methods

400 patients were compared in a propensity-matched analysis between CT- and Achieve catheter guided CBA (Control group; N=200) and Achieve catheter guided CBA with additional EnSite voltage maps performed pre- and post-CBA (Mapping group; N=200). Matching parameters were age, AF type and CHADS-VASc score. In patients undergoing repeat procedure, PV status was evaluated using CARTO mapping system.

Results

Baseline characteristics did not differ between both groups (Persistent AF: 47,5% vs. 46,5%, P=0,841; diagnosis-to-ablation time: 28,1±15,1 vs. 33,2±41,7months, P=0,107). The mapping group had a shorter follow-up time (25,6±7,2 vs. 50,3±3,3months, P<0,001). Repeat ablation was performed in 20 patients in the mapping group and 70 patients in the control group. At repeat, the proportion of patients with persistent complete PVI was higher in the mapping group (14/20(70.0%) vs 23/70(32,9%), P=0,030). Interestingly, less reconnections of the right inferior PV were seen in the mapping group (10,0% vs. 34,3%, P=0,035). There was no difference in reconnection rate of other PVs.

Conclusions

The addition of electro-anatomical EnSite mapping to the Achieve catheter improves PVI durability as seen during repeat ablation, mainly at the level of the right inferior PV. This finding might explain the improvement in 1-year outcome of this approach.
Peak frequency mapping characteristics in patients with scar-related atypical atrial reentrant tachycardias; findings from a novel automated annotation algorithm to detect near field signals
Authors: Yorgun H , Kilic S , Coteli C , Aytemir K
Published: May 2024

Background

Atypical atrial tachycardias are commonly encountered rhythm disorders especially in patients with atrial low-voltage areas mainly due to previous catheter ablations or surgery. The peak frequency (PF) analysis of bipolar EGMs is a novel automated annotation tool which is mainly based on differentiation of near field signals from far field signals.

Purpose

In this study, we aimed to evaluate the association between PF analysis of voltage maps in low-voltage zones with the critical isthmus and termination sites of ATs.

Methods

In this retrospective analysis, we included a total of 36 patients (7 with right AT, 25 left AT, 4 biatrial). Omnipolar maps of RA and LA were created during AT using Ensite X Mapping system and HD-Grid catheter. Normal voltage is defined as ≥ 0.5 mV, borderline 0.1-0.5 mV and scar <0.1 mV. Only patients with acute termination of tachycardia with RF ablation were included. The sites within the 10 mm radius from the tachycardia termination site with RF were analysed in terms of voltage characteristics and PF analysis.

Results

The mean age of the study population was 53±15. Among 36 patients a total of 46 activation maps were created and 44 reentrant ATs were mapped. (24 (54.6%) ATs were macroreentry, 17 (38.6%) ATs were localized reentry and 3 ATs (6.8%) were dual-loop reentry). The low-voltage (LV) zones comprised 31.5±20.6% and 24.5±12.6% of total LA and RA, respectively. All AT termination sites using radiofrequency energy were located within the LV zones having high frequency activity using 250 Hz as the cut-off. The sensitivity of LV-NF zones to predict termination sites of re-entry was 97.2%.

Conclusion

The PF analysis of atrial substrate in the vicinity of the termination site of re-entrant ATs demonstrated high frequency signals within the low voltage zones. Therefore, addition of PF analysis with emphasis over voltage mapping may refine critical sites of reentry in LV regions.
Ablation of persistent atrial fibrillation based on atrial electrogram duration map: methodology and clinical outcomes from the AEDUM pilot study
Authors: Magnocavallo M , Rossi P , Cauti F M , Polselli M , Niscola M , Limite L R , Bisignani A , Bianchi S
Published: May 2024

Background

Catheter ablation of persistent atrial fibrillation (PsAF) represents a challenge for the electrophysiologist and there are still divergences regarding the best ablative approach to adopt.

Objectives

Create a new map of the duration of atrial bipolar electrograms (Atrial Electrogram DUration Map, AEDUM) to recognize a functional substrate during sinus rhythm and guide a patient-tailored ablative strategy for PsAF.

Methods

40 PsAF subjects were assigned in a 1:1 ratio to either for PVI alone (Group B1) or PVI+AEDUM areas ablation (Group B2). A cohort of 15 patients without AF history undergoing left-sided accessory pathway ablation was used as a control group (Group A). In all patients, voltage and AEDUM maps were created during sinus rhythm. The minimum follow-up was 12-months, with rhythm monitoring via 48-h ECG Holter or by implantable cardiac device.

Results

Electrogram (EGM) duration was higher in Group B than in Group A (49±16.2ms vs 34.2±3.8ms; p-value<0.001). In Group B the mean cumulative AEDUM area was 21.8±8.2cm2; no difference between the two subgroups was observed (22.3±9.1cm2 vs 21.2±7.2cm2; p-value=0.45). The overall bipolar voltage recorded inside the AEDUM areas was lower than in the remaining atrial areas [median:1.30mV (IQR:0.71–2.38mV) vs 1.54mV (IQR:0.79–2.97mV); p-value:<0.001)]. Low voltage areas (<0.5mV) were recorded in three (7.5%) patients in Group B. During the follow-up [median 511 days(376-845days)] patients who underwent PVI-only experienced more AF recurrence than those receiving a tailored approach (65% vs 35%; p-value=0.04).

Conclusions

All PsAF patients exhibited AEDUM areas. An ablation approach targeting these areas resulted in a more effective strategy compared with PVI only.AEDUM mapAEDUM map and lesion set
Pulsed field ablation for complex resistant atrial tachycardia recurring after radiofrequency ablation of persistent atrial fibrillation
Authors: Fiala M , Cernosek M , Lehar F , Bulkova V , Funasako M , Bahnik J , Rybka L , Toman O , Kala P
Published: May 2024

Background

There is a limited knowledge on immediate and long-term efficacy of pulsed field ablation (PFA) for residual atrial tachycardia (AT) recurring after persistent atrial fibrillation ablation (AF).

Purpose

To present immediate and medium-term outcome of PFA (Farapulse) for complex AT recurring after ≥1 radiofrequency ablation (RFA) of primary (longstanding) persistent AF.

Methods

In 5/2022-10/2023, 81 patients (64±8 years, 19 females) underwent PFA for complex AT in 83 PFA procedures after prior RFA procedure(s); in first (n=21), second (n=33), third (n=23), fourth (n=5), or fifth (n=1) repeat ablation procedure, respectively. Mapping/ablation strategy was directed by the CS activation/entrainment to: 1) no 3D mapping and direct PFA in left atrium (n=67); 2) PFA directly after 3D LA mapping (n=9); 3) PFA following RFA after 3D LA mapping (n=7). AT sources were classified as macroreentry (MRAT) (perimitral, roof-dependent, typical flutter) or localized (LOCAT) in case of smaller reentry or ectopic origin.

Results

At the procedure onset, persistent AT was present in 58 patients, in the remaining cases AT (n=21) or AF (n=4) were induced. AF eventually occurred at some time of procedure in another 10 patients and was terminated by ablation at LA ridge/CS/LOM region 8x, LA posterior wall 3x, LUPV 1x, RUPV 1x, and RA low lateral wall 1x. Only MRAT, only LOCAT, or both AT types were found at 34 (41%), 35 (42%), and 14 (17%) procedures, respectively. A total of 125 ATs was identified (1, 2, and 3 ATs in 52, 20, and 11 patients). MRAT (n=60) included 32 perimitral ATs, 20 roof-dependent ATs, and 8 typical flutters. LOCAT (n=65) included RUPV source (n=1), LA extraPV sources (n=59), and RA sources (n=5). SR was restored with a 5±7 PFA applications at the site of AF source, total of PFA deliveries was 71±27, and procedure and fluoroscopy times were and 89±37 and 9±5 minutes, respectively. In the 7 patients with initial ineffective 6, 6, 11, 5, 18, 10, and 2 minutes of RFA, the AT was converted into SR by subsequent 1, 4, 1, 13, 4, 24, and 20 PFA applications. All ATs were terminated and noninducibility was achieved in 82 (99%) and 74 (89%) procedures, respectively. In 52 patients with >3 month follow-up, 46 (88%) patients remain in stable SR (41 / 79%) off AAD); 3 and 3 patients have paroxysmal or persistent AT.

Conclusion

PFA with catheter Farapulse can affect complex/epicardial AT sources resistant to RFA in prior or present ablation procedure; however, there is a certain discrepancy between high efficacy in AT terminating and medium-term clinical outcome.
Gender-specific aspects of long-term CryoPVI efficacy
Authors: Rothe M , Boehmer A A , Nussbaum E , Wiedenmann L , Schneider K , Spork P , Keim C , Dobre B C , Kaess B M , Ehrlich J R
Published: May 2024

Background

While a gender-specific influence has been demonstrated for many cardiovascular interventions, no prospective data is yet available for cryoballoon pulmonary vein isolation (CryoPVI).

Methods

We prospectively analyzed consecutive AF patients who underwent a first CryoPVI in a single-center cohort between 2018 and 2023. We stratified patients regarding gender into two groups. CryoPVI was performed in a standardized procedure. Foollow-up was performed at 3, 6, 12, 18, 24 and 36 months after CryoPVI. Efficacy endpoint was the occurrence of symptomatic atrial arrhythmia while major inguinal complications, phrenic nerve injury, stroke or death were considered safety endpoints. Periprocedural parameters were observed.

Results

During the study period 1180 patients underwent CryoPVI. Of these, 511 patients were female (43.3%). Female patients were significantly older (72.1 vs 67.3 years; p<0.001); had higher CHADS-VASc (3.4 vs 2.3; p<0.0001) and left ventricular ejection fraction (55.7 vs 53.9 p=0.001). There were no differences regarding AF phenotype (persistent AF 40.7% vs 59.3% p=0.17). The incidence of primary efficacy endpoint after 36 months was significantly higher in female patients (48.9% vs. 42.5%, p=0.0064). Safety endpoints occurred in form of phrenic nerve injury in one female patient (0.2%), one stroke in both groups (female 0.2% vs male 0.1%) and three major inguinal complications in both groups (female 0.6% vs male 0.4%).

Conclusion

In female patients CryoPVI is equally safe but less effective. The reason for the different therapeutic success remains unclear but should be considered for an individualized approach.
Ablation of premature ventricle contraction arising from papillary muscle without intracardiac echo using point-by-point mapping
Authors: Popara J , Maslova V , Zaman A , Sprenger L , Kleinhans L , Jahn O , Frank D , Demming T , Pantlik R , Lyan E
Published: May 2024

Background

 Catheter radiofrequency ablation (RFA) of ventricular arrhythmias (VAs) arising from the left ventricle's papillary muscles (PM) has been associated with inconsistent results due to difficulties in 3D reconstruction of this intraventricular structure. The use of intracardiac echo-guided ablation allows for the 2D visualisation of the PM and the guiding of ablation catheter. Cryo energy allows stable contact with the target structure during ablation. These two techniques have been shown to increase the success rate of ablation (77% reported - 1) but don’t allow the construction of the 3D map of papillary muscle with activation during PVC. Using a combination of point-by-point mapping (PbP) along with "fast anatomical mapping" (FAM) (Carto® 3 System) allows 3D reconstruction of the PM geometry with activation. These may increase the accuracy of PVC origin targeting.

Aim

This study aims to assess the feasibility and success rate of RFA of PVC arising from the papillary muscles of the left ventricle.

Methods and results

 We retrospectively analysed 214 patients treated with RFA for PVCs in two institutions. PVC arose from PM in 12(5.6%) cases (65±20 years old; 42% males; 33% with ejection fraction>50%; 8.3% antero-lateral PM). Initial detailed FAM of the left ventricle was performed using PVC pattern matching via transaortic or transmitral approach. Then, all points with preexcitation to QRS onset were copied from FAM into the new PbP map. That automatically created the geometry of PM with an activation map inside the LV shell. Irrigated high power (50 W) RFA was performed at the site of earliest activation at the PM shell. The acute success rate was 75% (n=9) without complications. PVC recurrence at 12-month follow-up was 11% (n=1 out of 9).

Conclusions

 RFA of PVC arising from papillary muscles using point-by-point mapping is feasible and associated with a success rate comparable to the previously reported one when intracardiac echo-guided ablation is used.
Safety and efficacy of a temperature-controlled ablation system for ventricular tachycardia: first results from the TRAC-VT study
Authors: Dhanjal T , Moreno J , Tondo C , Anselme F , Jacobs S , Burrell J , Becker D , Peichl P , Patchett I , Kautzner J
Published: May 2024

Background

Catheter ablation using radiofrequency (RF) energy, is a well-recognized treatment option for patients with ventricular arrhythmias. However, procedural complications may be high, and efficacy is often suboptimal with high recurrence rates.

Purpose

The TRAC-VT study evaluated safety and efficacy of the DiamondTemp Ablation (DTA) System for the treatment of patients with ventricular arrhythmias by catheter ablation.

Methods

A temperature-controlled, irrigated RF catheter (with six thermocouples and an internal network of diamond coatings) was utilized to treat subjects with either sustained monomorphic ventricular tachycardia (VT) and structural heart disease or with frequent monomorphic symptomatic ventricular premature beats (VPBs) and normal hearts. Patients were enrolled at five hospital centers in five European countries and were followed for 6 months. Ablation was performed in temperature-control mode with an irrigation flow of 8 mL/min for all power deliveries. The target temperature was set to 55 or 60 °C with a power output limited to 50 Watts. RF energy was applied for a maximum of 45 seconds per target site, depending on impedance drop and electrogram abatement.

Results

The study enrolled 49 subjects (age 67±12 years, 80% male) in total (38 with sustained monomorphic VT and structural heart disease and 11 with symptomatic VPBs). In all cases, mapping and navigation was used with EnSite systems (Abbott). The average ablation time (defined as time from the insertion of the DTA catheter until removal from body) was 87 ± 44 minutes. During this time, RF energy was applied for an average of 28.2 ± 10.2 seconds with a power of 44.0 ± 7.0 W and a temperature of 50.9 ± 3.9 °C during 35.0 ± 23.2 applications. Acute procedural success was 100% (93%-100%), and it was defined as the elimination of VPBs or non-inducibility for sustained VT (using solely the DTA catheter). The primary safety procedure-related endpoint was an evaluation of cardiovascular-related death, stroke / TIA, cardiac tamponade/perforation, bleeding complication, myocardial infarction, thromboembolism, and pulmonary edema. In total review of the primary safety endpoint, one subject had a confirmation of a stroke / TIA event. Regarding longer term procedural efficacy, the 6-month follow-up was completed in 92% of subjects. For the whole study population chronic success from recurrence of ventricular arrhythmia (faster than 100 beats/min after 6 months) was 73.4% (58.6%-83.6%) for non-sustained ventricular arrhythmias (≥3 beats) and 87.7% (74.7%-94.3%) for sustained ventricular arrhythmias (≥30 sec).

Conclusions

VT/VPBs ablation using a temperature-controlled irrigated RF catheter was safe and effective with low VT recurrence at 6 months of follow-up.
Comparison of continuity index by atrial fibrillation type with the use of active esophageal cooling
Authors: Sherman J , Putzel N , Lazarus C , Gallagher M , Ro A , Nazari J , Fisher W , Kulstad E , Metzl M
Published: May 2024

Background/Introduction

Proactive esophageal cooling is FDA cleared to reduce the likelihood of esophageal injury during radiofrequency (RF) ablation for the treatment of atrial fibrillation (AF). Recent data suggest improved long-term freedom from arrhythmia with cooling, which may result from a lower continuity index with cooling that in turn improves the durability of pulmonary vein isolation (PVI).

Purpose

To measure and compare the continuity index obtained using proactive esophageal cooling in PVI of paroxysmal and persistent AF.

Methods

The continuity index was prospectively calculated for PVI cases of paroxysmal and persistent AF performed by 4 providers between June and September 2023. The continuity index was quantified by the lesion placement order, such that each lesion placed that did not border a previous lesion increased the continuity index by 1 unit. Published data have suggested a continuity index below 6 results in optimum long-term isolation, whereas a continuity index above 6 leads to more gaps, less isolation, and greater AF recurrence.

Results

Data from a total of 71 patients were recorded. Mean patient age was 69.8±9.0, with 43% female, and 28 with paroxysmal, 43 with persistent AF. The mean±SD continuity index for PVI was 2.6±3.8. The mean continuity index was similar between paroxysmal (2.9±3.4) and persistent (2.4±3.9) AF patients, and similar for the left pulmonary veins and on the right (Table 1). Only 5% (4) patients had a continuity index above 6 on either side.

Conclusions

The use of proactive esophageal cooling during RF ablation results in attainment of a low continuity index in PVI of both paroxysmal and persistent AF. This may contribute to the higher rates of freedom from arrhythmia seen with active cooling to date.Table 1
One-year freedom from arrhythmia following radiofrequency ablation using proactive oesophageal cooling
Authors: Gallagher M M , Akhtar Z , Kontogiannis C , Sohal M , Hayat J , Joseph C , Nazari J , Zagrodzky J , Brumback B , Sherman J , Zagrodsky W , Bailey S , Kulstad E , Metzl M , Leung L W M
Published: May 2024

Background

Proactive esophageal cooling is increasingly being utilized, and is now FDA cleared, to reduce the likelihood of ablation-related esophageal injury resulting from radiofrequency (RF) cardiac ablation of atrial fibrillation (AF). One-year follow-up from the largest randomized controlled study, the IMPACT trial, showed a trend towards improvement in long-term efficacy versus luminal esophageal temperature (LET) monitoring. With larger data sets now available for analysis, we sought to determine 1-year freedom from atrial arrhythmia associated with the use of proactive esophageal cooling.

Methods

Data from 2 trials comparing freedom from atrial arrhythmia after RF ablation using proactive esophageal cooling to LET monitoring were combined. Data were analyzed using a stratified Cox proportional hazards model to compare arrhythmia recurrence rates, with R statistical analysis software.

Results

Data from 631 patients across two studies comparing arrhythmia outcomes for proactive oesophageal cooling versus LET monitoring were analysed. Mean patient age was 66.4±9.8 years, and 37.4% were female. Arrhythmias were 56.3% paroxysmal AF and 43.7% persistent or long-standing persistent AF. Freedom from atrial arrhythmia at one year was 77.2% for patients receiving proactive oesophageal cooling and 64.4% for patients receiving LET monitoring (Figure 1), with a hazard ratio for cooling of 0.65 (95% CI 0.43 to 0.99, P = 0.044).

Conclusions

Proactive oesophageal cooling was associated with significantly greater freedom from atrial arrhythmia at one year when compared to LET monitoring during RF ablation.
Characterization and clinical significance of hemolysis after pulsed-field ablation for atrial fibrillation: insights from a multicentric analysis
Authors: Popa M A , Venier S , Mene R , Della Rocca D , Sacher F , Derval N , Hocini M , Combes S , Albenque J P , Saitta F , Chierchia G B , De Asmundis C , Defaye P , Boveda S , Jais P
Published: May 2024

Background

Pulsed-field ablation is a novel non-thermal ablation modality which is being increasingly used in clinical practice for the treatment of atrial fibrillation (AF). While the susceptibility of erythrocytes to electroporation is well-established, the effect of cardiac PFA technologies on erythrocyte destruction has not been described so far.

Purpose

The aim of this study was to investigate whether PFA induces clinically significant hemolysis.

Methods

We included 187 patients undergoing AF catheter ablation with either PFA (n=145) or RFA (n=42) at four high-volume centers. PFA was performed using a pentaspline catheter (biphasic, bipolar pulses of 2kV) and RFA with a 3.5 mm irrigated-tip catheter (40-60 W). The lesion set comprised pulmonary vein isolation (PVI) for paroxysmal AF and PVI ± additional lesions/lines for persistent AF. Established biomarkers of hemolysis, anemia and renal function were analyzed in blood samples obtained at baseline (T1), at the end of ablation (T2) and 24 hours after the procedure (T3).

Results

Baseline characteristics were well-balanced between groups (65.5 ± 9.6 years, 72.7% male, p>0.05). The ablation procedures comprised a mean of 61.4 ± 27.2 deliveries (PFA group) and a mean RF duration of 31.0 ± 16.3 min (RFA group). Atrial ablation in addition to PVI was performed in 55.2% vs. 61.9% patients, respectively (p=0.469). The direct hemolysis marker free plasma hemoglobin was significantly higher with PFA (592.8 ± 330.6 mg/dl) than with RFA (186.6 ± 215.8 mg/dl, p<0.001) at the end of ablation. A strong correlation was found between free plasma hemoglobin and PFA deliveries (Pearson r=0.615, p<0.001). PFA was further associated with a 2.2-fold increase in bilirubin (21.3 ± 11.3 vs. 9.6 ± 4.7 µmol/l), a 2.4-fold decrease in haptoglobin (0.5 ± 0.4 vs. 1.2 ± 0.4 g/l) and a 1.8-fold increase in LDH (352.7 ± 115.7 vs. 192.2 ± 51.6 U/l, T3 vs. T1, all p<0.001). There were no significant changes in bilirubin and haptoglobin in the RFA group (p>0.05). A slight decrease in red blood cells, hemoglobin and hematocrit was detected after both PFA and RFA (Abstract Figure), with no significant differences between groups (all p>0.05). While mean creatinine levels and glomerular filtration rates did not significantly change after ablation in either group, acute kidney injury occurred in 4/124 (3.2%) with PFA vs. 0/32 (0%) with RFA (p=0.303).

Conclusion

Intravascular hemolysis is a frequent finding after PFA for AF and increases with the number of PFA deliveries. While PFA was not associated with clinically significant anemia, the incidence of acute kidney injury in the present study warrants future large-scale investigations assessing the biological impact and nephrotoxicity of PFA-induced hemolysis.Abstract Figure
Radiofrequency lesion in atrial wall: how variable is it? 9 Tesla MRI analysis of RF lesion volume in a swine model
Authors: Cardelli L S , Laumont T , Beghian J , Achahli Y , Cardoso M , Peltier M , Pasquie' J L , Granier M
Published: May 2024

Background

Little is known about radiofrequency (RF) lesion volume (rLV). Most of animal or ex-vivo studies quantify the size of RF lesions size using width and/or depth, while electrophysiologists use manufacturers’ indirect indices (such as Ablation Index or Lesion Size Index).

Purpose

We aimed to evaluate rLV by high resolution 9-Tesla magnetic resonance imaging (MRI), in ex-vivo swine model. We studied the variability of rLV and extra-cardiac effects in two groups of swine, one treated with low energy (LE)-long application RF (20W-50 sec) and another treated with high energy (HE)-short application RF (50 W-20 sec).

Methods

This was a prospective observational study on 18 piglets, that were anesthetized, mechanically ventilated, and divided into LE (n = 9) and HE (n = 9) groups (Figure 1). An irrigated contact force catheter was used to perform RF applications in 4 largely separated spots: 2 on right atrium and 2 on left atrium wall. RF parameters were monitored during RF. Each animal was sacrificed after 5-7 days, and RF lesion samples were excised and acquired by 9 MRI.

Results

70 RF applications were performed (36 in LE group and 34 in HE group). MRI was performed on 26 samples of LE group and 28 of HE group (Figure 2). The median RF lesion volume was 89.3 mm3 (IQR 47.9-175.9). Regarding lesion volume, the HE groups showed 35% higher volume than LE group (mean lesion volume 86.2 mm3 vs 116.3 mm3, p = 0.119). HE group also showed more complications (0 vs 7, p=0.02) and more extracardiac lesion (14 vs 18, p=0.613).

Conclusions

There was a wide and unpredictable variability of RF lesion on atrial wall, even under controlled experimental conditions, which could explain arrhythmias recurrences. The variability seems greatest, although not statistically significant, during HE applications. The dose/effect relationship needs to be carefully studied for treatments of cardiac arrhythmias for both RF and other forms of energy available today.Study flow-chartComparison between groups
The importance of scar border zone size in VT presentation and recurrence in post MI patients
Authors: Rademaker R , De Riva Silva M , Piers S R D , Wijnmaalen A P , Zeppenfeld K
Published: May 2024

Introduction

Available mapping data in post-myocardial infarction patients describe ventricular tachycardia (VT) re-entry circuit characteristics of slow VT, that are typically related to transmural scars. Fast VTs with cycle lengths close to the refractory period may be related to functional re-entry in the scar border zone. Functional re-entry related border zone VTs may be difficult to control by ablation.

Purpose

The aims of this study are (1) to describe electroanatomical voltage map (EAVM) characteristics in post myocardial infarction (MI) patients with spontaneous and inducible fast VTs and (2) to assess the relation between scar border zone size and ablation outcomes.

Methods

Consecutive post-MI patients undergoing VT ablation at a tertiary referral center from January 2012 to November 2018 were included. Fast VT was defined as a VT cycle length (VTCL) = ventricular refractory period + max. 30ms. Areas of scar border zone (using 0.5 – 2.1mV/3.0mV cut-offs (according to LV remodeling stage; LVEF<47% and LV end-systolic volume index of >50 ml/m2)) were measured on the EAVM and correlated with clinical outcomes.

Results

In total, 138 patients were included (86% male; left ventricular ejection fraction 35±10%; 86% remodeled LV). Twenty-three patients (17%) had ≥1 fast VT (mean VTCL 275±52ms) at presentation, mean VTCL of the remaining patients 397±88ms). The median scar border zone size was 27% [IQR 20-38] of the left ventricular endocardial surface. Patients who presented with a spontaneous fast VT had a larger border zone than patients with slower VT (32% [IQR 28 – 41] vs. 25% [IQR 16 – 36], p=0.01).

After ablation, 79 (57%) patients remained inducible for any VT, including 59/79 (75%) for a fast VT (median VTCL fast VT 260ms [IQR 236 -280]). Patients who remained inducible for fast VTs had a larger border zone than patients who remained inducible for slower VTs (35% [IQR 27 – 44] vs. 26% [IQR 20 – 36], p<0.001).

During a median follow-up of 26 months [IQR 8 – 47], 45 patients (33%) had a VT recurrence (mean VTCL 357±98ms). Patients with a below median (27%) scar border zone area had a lower VT recurrence rate compared to patients with an above median scar border zone area (recurrence rate: 16/66 (24%) vs. 29/72 (40%), p=0.03). Kaplan-Meier survival analysis showed better free VT survival in the below median border zone patients (Log-rank: p<0.05) (Figure 1).

Conclusion

Patients who present with spontaneous fast VTs or who remain inducible for fast VTs after ablation have larger scar border zones during EAVM compared to patients with presenting or remaining slower VTs. A larger border zone appeared to be associated with higher VT-recurrence rates. The scar border zone may play an important role as VT substrate for (fast) VTs and may not be easily targeted by current ablation techniques.VT-free survival stratified by median BZ
The effects of radiofrequency catheter ablation for atrial fibrillation on right ventricular function
Authors: Uhm J S , Kim M K , Park J W , Kim D , Yu H T , Kim T H , Joung B , Pak H N , Lee M H
Published: May 2024

Background

The effects of radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) on right ventricular (RV) function are not well known.

Methods

Patients who underwent RFCA for AF and underwent pre- and post-procedural echocardiography were enrolled. Fractional area change (FAC), RV free-wall longitudinal strain (RVFWSL), and RV 4-chamber strain (RV4CSL) were measured. Changes in FAC, RVFWSL, and RV4CSL before and after RFCA were compared among paroxysmal (PAF), persistent (PeAF), and long-standing persistent AF (LSPeAF) groups.

Results

A total of 164 participants (74 PAF, 47 PeAF, and 43 LSPeAF; age, 60.8±9.8 years; men, 74.4%) was enrolled. The patients with PeAF and LSPeAF had worse RV4CSL (p<0.001) and RVFWSL (p<0.001) than those with PAF and reference values. Improvements in RVFWSL and RV4CSL after RFCA were significant in the PeAF group compared with the PAF and LSPeAF groups (ΔRV4CSL, 8.4% [5.1–11.6] in PeAF vs. 1.0% [-1.0–4.1] in PAF, 1.9% [-0.2–4.4] in LSPeAF, p<0.001; ΔRVFWSL, 9.0% [6.9–11.5] in PeAF vs. 0.9% [-1.4–4.9] in PAF, 1.0% [-1.0–3.6] in LSPeAF, p<0.001).

Conclusions

RV function is impaired in patients with PeAF and LSPeAF than in those with PAF. RV function is more improved after RFCA in patients with PeAF than in those with PAF or LSPeAF.Changes of echocardiographic parameters
Low-dose dexmedetomidine sedation in patients undergoing electrophysiological study and ablation of supraventricular tachycardias in a same day setting
Authors: De Santis N , Vrenozaj R , Crocamo A , Bearzot L , Guidorossi A , Niccoli G , Ardissino D , Notarangelo M F
Published: May 2024

Background

Catheter ablation for supraventricular tachycardias (SVT) can frequently cause patient discomfort, anxiety or pain. Through the years different drugs have been employed to provide an optimal sedation without interfere with inducibility of tachyarrhythmia. Moreover, the increasing number of patients with this clinical condition and the growing demand of catheter ablation, makes same day discharge mandatory. For this purpose, drugs that guarantee minimal sedation and reduce adverse events should be used. Dexedetomidine (DEX) is a selective alpha-2 agonist with analgesic and sedating effect without significant respiratory depression. Its electrophysiological effects include the sinus node and atrioventricular (AV) node depression and an increased atrial refractoriness. Albeit there is a reduction of side effects of most commonly used sedation drugs, data on the efficacy and safety profile of DEX during SVT ablation of adult patients are unclear and conflicting.

Purpose

The aim of this study was to assess whether optimal sedation and patient’s comfort can be achieved with a low-dose DEX without interfering with electrophysiological parameters during catheter ablation of SVT in adult population.

Methods

This is a single-center prospective study. Study population consisted of patients undergoing mapping and catheter ablation of SVT from January to September 2023 divided into DEX group (periprocedural infusion of Dexedetomidine 0.07-0.11 mcg/kg/h without loading dose) and non-DEX group (midazolam 1-2 mg periprocedural). Clinical and procedural data were recorded for all patients, as well as all measurements taken during electrophysiological study.

Results

The study population was predominantly female (60%) with a mean age of 56 ± 13.7 years. Hypotension occurred in only one patient, in the DEX group. No cases of desaturation were observed in both groups. Most of the induced tachyarrhythmias were the slow-fast type of atrioventricular nodal reentrant tachycardia (75%), whereas atrioventricular reentrant tachycardia and atrial tachycardia were less common (7.1% and 7.1%). No significant differences were recorded in relation to AV node refractoriness, atrial refractoriness, anterograde and retrograde conduction. (Table 1) Isoproterenol was required to induce tachyarrhythmia in both groups. Arrhythmia inducibility and aberrancy in tachycardia was not significantly influenced by DEX. The jump phenomenon was recorded more frequently in the DEX group (86.4% vs. 46.7%; p=0.004). The mean duration of the procedure did not differ between the two groups. All patients were discharged on the same day after 3 hours of observation.

Conclusions

The use of low-dose Dexedetomidine was succesful in improving periprocedural patient comfort, without reducing tachyarrhythmia inducibility or major electrophysiological parameters.
Risk of death and thromboembolic events in patients with supraventricular arrhythmias admitted to the emergency department
Authors: Bucci T , Proietti R , Lip G Y H
Published: May 2024

Background

Few data are available on the risk of death and thromboembolism in patients with supraventricular tachycardia (SVT).

Purpose

To assess the risk of adverse events in SVT patients admitted to the emergency department (ED).

Methods

Retrospective study utilizing a global federated health research network (TriNetX). Based on the ICD codes recorded at the ED admission, patients were categorized in: SVT (I41.1), atrial fibrillation (AF, I48.0,1,2,91), atrial flutter (I48.3,4,92), and a control group with palpitations (R00.2) without arrhythmias (CTRL). Primary outcome was the 1-year risk of a composite of all-cause death and thromboembolism (ischemic stroke, transient ischemic attack, and peripheral arterial embolism). Secondary outcomes were the 1-year risk of each component of the composite outcome. Cox-regression analysis was used to produce hazard ratios (HRs) and 95% confidence intervals (CI) after 1:1 propensity score matching (PSM). The exploratory analysis was performed to assess the risk of first episode of thromboembolism. Other sensitivity analyses were performed to validate the results of the main analysis in patients ≥65 years, with multimorbidity, and not on oral anticoagulation (OAC).

Results

We identified 37,793 SVT patients (58.5±19.2 years, 55.8% females), 239,490 AF patients (70±19.2 years, 47.3% females), 20,674 atrial flutter patients (68.6±15.1, 15.1% females), and 89,152 CTRL (43.5±17.8 years, 60.1% females). Before PSM, in SVT patients the mean age and the prevalence of cardiovascular risk factors was lower than AF and atrial flutter patients but higher than CTRL. After PSM, no difference was found among the three groups. After PSM, the risk of composite outcome in SVT patients was higher compared to CTRL (HR 2.80, 95%CI 2.61-3.00), similar to atrial flutter patients (HR 0.98, 95%CI 0.94-1.03), and a lower compared to AF patients (HR 0.85, 95%CI 0.82-0.88) (Figure 1). These results were consistent also for the secondary outcomes, for the risk of the first thromboembolic event (Figure 2), and in all the sensitivity analyses.

Conclusion

SVT patients have a risk of death and thromboembolism comparable to those with atrial flutter, but lower than AF. Further studies are needed to evaluate the possible beneficial effect of OAC in this clinical context.Figure 1Figure 2
Arrhythmic risk stratification in non-ischemic cardiomyopathy using cardiovascular magnetic resonance
Authors: Zegard A , Hammersley D , Androulakis E , Jones R , Okafor O , Mach L , Lota A , De Marvao A , Guha K , Tayal U , Pennell D , Halliday B , Qiu T , Prasad S , Leyva F
Published: May 2024

Background

Myocardial fibrosis (MF) is an essential component of the arrhythmic substrate for ventricular arrhythmias (VAs).

Aims

To determine whether total myocardial fibrosis (TF) and gray zone fibrosis (GZF), assessed using cardiovascular magnetic resonance, are better than LVEF in predicting ventricular arrhythmias in patients with non-ischemic cardiomyopathy (NICM).

Methods and results

Patients with NICM in a derivation cohort (n=866) and a validation cohort (n=848) underwent quantification of TF and GZF. The primary composite endpoint was sudden cardiac death (SCD) or VAs (ventricular fibrillation or sustained ventricular tachycardia). The primary endpoint was met by 52/866 (6.0%) patients in the derivation cohort (follow-up of 7.5 years [interquartile range, IQR] 5.2-9.3). In competing risk analyses, MF on visual assessment (MFVA) predicted the primary endpoint (hazard ratio [HR] 5.83, 95% confidence intervals [CI] 3.15-10.8). Quantified MF measures permitted categorization into 3 risk groups: a TF >0 ≤ 10 g was associated with an intermediate risk (HR: 4.03 [95% CI 1.99-8.16]) and a TF > 10g with the highest risk (HR: 9.17 [95% CI 4.64-18.1]) compared to no MFVA (lowest risk) (Figure). Similar trends were observed in the validation cohort. Categorization into 3 risk groups was achievable using TF or GZF in combination or in isolation. In contrast, LVEF<35% was a poor predictor of the primary endpoint (validation cohort HR:1.99, 95% CI 0.99-0.41).

Conclusions

MFVA is a strong predictor of SCD and VAs in NICM. TF and GZF mass added incremental value to MFVA. In contrast, LVEF was not useful in arrhythmic risk stratification.
What Can IIAs Contribute to Regulating Cross-border Data Transfer: A Threshold Analysis
Authors: Zhang Qianwen
Published: May 2024

States are using legislation to regulate cross-border data transfer, which has raised new concerns that international investment agreements (IIAs) may be used to protect foreign investment. According to current IIA texts and arbitration practices, some data is likely to be regarded as ‘investment’, but indefinite data ownership and invisibility ‘in the territory’ make use traditional IIA structures to regulate cross-border data transfer uncertain. What IIAs can contribute to regulating cross-border data transfer has a significant impact on the protection of foreign investments. IIAs need to be reformed to keep their vitality in the face of the challenges brought by digital technology. As a response, they can clarify essential concepts, including when is data an ‘investment’ and who is the ‘investor’ that is entitled to bring claims. Considering the distinct data realms, IIA reform is more likely to be initiated through bilateral or regional negotiations among States with similar cultures or complementary interests.
Normal Completions of Toric Varieties Over Rank One Valuation Rings and Completions of Γ-Admissible Fans
Authors: Friedenberg Netanel
Published: May 2024

We show that any normal toric variety over a rank one valuation ring admits an equivariant open embedding in a normal toric variety which is proper over the valuation ring, after a base-change by a finite extension of valuation rings. If the value group $\Gamma $ is discrete or divisible then no base-change is needed. We give explicit examples that show that existing methods do not produce such normal equivariant completions. Our approach is combinatorial and proceeds by showing that $\Gamma $-admissible fans admit $\Gamma $-admissible completions. In order to show this we prove a combinatorial analog of Noetherian reduction, which we believe will be of independent interest.
Activity of ceftolozane/tazobactam and imipenem/relebactam against Gram-negative clinical isolates collected in Mexico—SMART 2017–2021
Authors: Karlowsky James A , Lob Sibylle H , Siddiqui Fakhar , Polis Thales , Vallejo Jose L , Young Katherine , Motyl Mary R , Sahm Daniel F
Published: May 2024

Objectives

To investigate the activities of ceftolozane/tazobactam and imipenem/relebactam against Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa isolated from hospitalized patients in Mexico in 2017–2021.

Methods

MICs were determined by CLSI broth microdilution and interpreted using CLSI M100 breakpoints. β-Lactamase genes were identified in ceftolozane/tazobactam-, imipenem/relebactam-, and/or imipenem-non-susceptible isolates.

Results

Ceftolozane/tazobactam and imipenem/relebactam inhibited 89% and 99% of E. coli isolates (n = 2337), and 87% and 94% of K. pneumoniae isolates (n = 1127). Sixty-four percent of E. coli and 47% of K. pneumoniae had an ESBL non-carbapenem-resistant Enterobacterales (ESBL non-CRE) phenotype. Eighty-six percent and 91% of ESBL non-CRE E. coli and K. pneumoniae were ceftolozane/tazobactam susceptible, and 99.9% and 99.8% were imipenem/relebactam susceptible. Ceftolozane/tazobactam was the most active agent studied against P. aeruginosa (n = 1068; 83% susceptible), 9–28 percentage points higher than carbapenems and comparator β-lactams excluding imipenem/relebactam (78% susceptible). Ceftolozane/tazobactam remained active against 35%–58%, and imipenem/relebactam against 32%–42%, of P. aeruginosa in meropenem-, piperacillin/tazobactam-, and cefepime-non-susceptible subsets. The majority of isolates of ceftolozane/tazobactam-non-susceptible E. coli carried an ESBL, whereas among ceftolozane/tazobactam-non-susceptible K. pneumoniae and P. aeruginosa, the majority carried carbapenemases. The most prevalent carbapenemase observed among E. coli (estimated at 0.7% of all isolates), K. pneumoniae (4.8%) and P. aeruginosa (10.0%) was an MBL. Almost all imipenem/relebactam-non-susceptible E. coli and K. pneumoniae carried MBL or OXA-48-like carbapenemases, whereas among imipenem/relebactam-non-susceptible P. aeruginosa, 56% carried MBL or GES carbapenemases.

Conclusions

Ceftolozane/tazobactam and imipenem/relebactam may provide treatment options for patients infected with β-lactam-non-susceptible Gram-negative bacilli, excluding isolates carrying an MBL- or OXA-48-like carbapenemase.