bluuebunny/crossref_metadata_2025_split huggingface dataset:
Esophageal cooling during ablation of persistent atrial fibrillation is associated with improved freedom from arrhythmia at one-year follow up
Authors: Joseph C , Nazari J , Zagrodzky J , Sherman J , Zagrodzky W , Bailey S , Ro A , Fisher W , Metzl M 
Published: October 2022

Abstract

Background
Various factors influence successful freedom from atrial arrhythmia after pulmonary vein isolation (PVI) with radiofrequency (RF) ablation for the treatment of atrial fibrillation (AF). Lesion transmurality and continuity (as measured by the Continuity Index) are two important factors, and these can be worsened by pauses in RF energy application due to esophageal overheating. Proactive esophageal cooling precludes the need for premature cessation of power, avoiding partially-formed lesions and the need to “hop-scotch” in the left atrium. The resulting improvement in lesion continuity may improve long-term freedom from atrial arrhythmia after PVI, particularly in patients with persistent AF, where more posterior wall ablation is often necessary.

Purpose
Determine differences in freedom from arrhythmia at one year between patients receiving LET monitoring and those receiving esophageal cooling during PVI for persistent AF.

Methods
We reviewed data from two healthcare systems for patient rhythm status at one-year follow up after PVI for the treatment of persistent or long-standing persistent AF. We then determined Kaplan-Meier estimates of freedom from arrhythmia (AF, atrial flutter, and atrial tachycardia), and compared these between patients receiving esophageal cooling and those treated with traditional LET monitoring.

Results
A total of 252 patients received PVI for persistent or long-standing persistent AF and had data available for review. Of these, 148 received LET monitoring (with either a single or multi-sensor temperature probe), and 104 received active cooling with a dedicated esophageal cooling device. Mean age and gender for each group was similar (67.2, range 21 to 88 years, 36% female for LET monitoring, and 67.8, range 32 to 89 years, 30% female for esophageal cooling). KM estimates for freedom from AF at the one-year follow-up were 44.2% for LET monitored patients and 79.3% for actively cooled patients (P=0.01).

Conclusions
Freedom from atrial arrhythmia at one-year after PVI for persistent AF is associated with significant improvement when using active esophageal cooling rather than LET monitoring.

Funding Acknowledgement
Type of funding sources: Private company. Main funding source(s): Attune Medical
The left atrial low-voltage area and persistent atrial fibrillation treated with pulmonary vein isolation alone
Authors: Kwon S , Choi E K , Lee S R , Ahn H J , Oh S 
Published: October 2022

Abstract

Background
There are limited data regarding the association between the burden of the left atrial low-voltage area (LVA) and the outcome of pulmonary vein isolation (PVI) alone in persistent atrial fibrillation (PeAF).

Purpose
The study aimed to investigate the impact of the burden of LVA on the patients with PeAF treated with PVI alone.

Methods
Using a retrospective cohort of PeAF patients who underwent PVI alone, both clinical and the left atrial voltage mapping data were reviewed. LVA was defined as an area of ≤0.5 mV (bipolar) when mapped during sinus rhythm and ≤0.2 mV during AF. The high burden of LVA was defined as a case when the LVA constitutes ≥10% of the total left atrial body area. The patients were categorized into either the high or low burden groups. The recurrence of any atrial tachyarrhythmia was followed up, and multivariable Cox's regression analysis was performed.

Results
A total of 50 and 25 patients were investigated for the low burden (LVA&lt;10%) and high burden (LVA≥10%) groups, respectively. Compared to the low burden group, the high burden group had a significantly less male proportion (56.0% versus 78.0%), a higher CHA2DS2-VASc score (median 3 versus 2), more chronic kidney disease (16.0% versus 2.0%), and a higher burden of LVA (20±11% versus 5±3%). During the median follow-up of 9.5 (6.2–16.2)months, there were 30.0% and 48.0% ofrecurrences for the low and high burden groups, respectively. Compared to the low burden group, the high burden group was associated with higher risks of both early and late recurrences (HR [95% CI] =2.67 [1.15–6.18] and 2.08 [1.03–4.20], respectively) (Figure 1). The best cut-off of LVA to predict 2-year recurrence was 10.1% (Figure 2).

Conclusion
The high burden of LVA was significantly associated with an increased risk of recurrence among PeAF patients treated with PVI alone. Tailored ablation in addition to PVI would be needed to improve outcomes in patients with PeAF having a high burden of LVA.

Funding Acknowledgement
Type of funding sources: None.
Recurrences after stereotactic arrhythmia radioablation for refractory ventricular tachycardia
Authors: Herrera Siklody C , Schiappacasse L , Jumeau R , Le Bloa M , Ozsahin M , Teres Castillo C , Moeckli R , Porretta A P , Pascale P , Domenichini G , Bourhis J , Pruvot E 
Published: October 2022

Abstract

Introduction
Stereotactic arrhythmia radioablation (STAR) has been recently introduced for the management of ventricular tachycardia (VT) refractory to antiarrhythmic drugs (AADs) and catheter ablation (CA). VT recurrences were recently reported after STAR but the mechanisms remain poorly known.

Purpose
We analyzed VT recurrences after STAR for refractory VT in order to assess the characteristics and delivered dose at sites of VT relapse.

Methods
From 09.2017 to 01.2020, 12 consecutive patients (pts) (66±8y, LVEF 40±14%) suffering from refractory VT were enrolled. The underlying cardiopathy was ischemic in 3, inflammatory in 3 and idiopathic in 6 pts. Nine (75%) out of 12 pts had a history of at least 1 electrical storm. Before STAR, an invasive electro-anatomical mapping (Carto3) of the VT substrate (VT-sub) was performed. A mean dose of 22±2Gy was delivered to the VT-sub using the Cyberknife® system.

Results
The ablation volume was 24±7cc and involved the basal interventricular septum (IVS) in 10 (83%) pts. During the first 6 months after STAR, VT burden decreased by 93% (mean value, from 640 to 46 VT/semester). After a median follow-up of 32±11 months, 10/12 (83%) developed ≥1 recurrence as a sustained VT and underwent a redo CA. Two (17%) pts presented 2 distinct VT recurrences from clearly different areas. VT recurrence was located at the border zone (BZ) of the treated VT-sub in 6 (50%) cases, involved both the BZ and a larger substrate in 2 (17%) cases, and occurred remote from the VT-sub in 4 (33%) cases (see Table 1). The dose delivered at sites of VT recurrence was 8.4±8.6 Gy with a large heterogeneity ranging from 0.11 to 28.37 Gy, for some pts due to dose constraints near critical structures (coronary arteries). Voltage mapping showed a small but significant reduction in both unipolar and bipolar EGM voltage in the irradiated area after STAR (before vs after, Bipolar: 1.8±1.2 vs 1.1±1.2 mV and Unipolar: 4.4±2.0 vs 3.4±2.3 mV, p=0.02 and 0.01 respectively). Importantly no pts developed a high-grade AV block after STAR despite IVS irradiation.

Conclusion
STAR appears to be an efficient tool for the management of refractory VT, leading to a strong VT burden reduction and no new high-grade AV block. Recurrences were nevertheless common, often at the border zone of the irradiated volume.

Funding Acknowledgement
Type of funding sources: Public hospital(s). Main funding source(s): CHUV
Novel electrogram featurization reveals a spectrum of response to ablation from atrial tachycardia to types of atrial fibrillation
Authors: Ganesan P , Rogers A J , Deb B , Feng R , Ruiperez-Campillo S , Tjong F V , Bhatia N , Clopton P , Rappel W J , Narayan S M 
Published: October 2022

Abstract

Background
Although atrial tachycardia (AT) may interconvert with fibrillation (AF) in many patients, it is undefined if this represents a pathophysiological spectrum of organization, or whether it indicates that AF will respond better to ablation.

Objective
To test the hypothesis that the spatial area within which electrograms (EGMs) repeat in synchronized fashion over time indicates a spectrum from AT, in which areas span the entire atria, to AF, in which areas are limited. We further hypothesized that repetitive areas would be larger in AF patients with acute termination than in those with poor response to ablation.

Methods
We studied N=234 patients (47% women, 64±10Y), of whom (i) N=10 had AT, (ii) N=120 had AF that terminated with ablation (“Term”), (ii) N=104 had AF that did not terminate (“Non-term”). All patients had global left atrial mapping by 64 pole baskets (Abbott, IL). Spatial areas of repetitive activity (REACT) were calculated by correlating unipolar EGMs in 2x2 grids for 4 sec, repeated for the entire atria (Figure 1A, B). We quantified global organization by averaging the REACT map for each patient.

Results
Figure 1C shows progressively decreasing areas of repetitive EGM from AT to AF Term to AF Non-term (p&lt;0.001, ANOVA). Figure 1D shows a case of AT in a 71 YO male and global REACT &gt;0.90, a case of AF REACT 0.45 in a 65 YO male with termination by ablation, and a case of AF with REACT 0.19 in an 85 YO male that did not terminate. Further, ROC analysis of REACT analysis in AF cases predicted termination with an AUC of 0.71.

Conclusion
Spatial areas of repeating electrogram shapes indicates a spectrum from AT to AF with good and AF with poor acute response to ablation. Future studies should investigate whether REACT areas can be identified non-invasively, such as by body surface ECG, to guide ablation or prognosis.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): US National Institutes of Health
Machine learned clusters explain heterogeneity in outcomes from map-guided ablation of Atrial Fibrillation results from the large PROspective STanford AF Registry (ProSTAR)
Authors: Deb B , Rogers A J , Bhatia N K , Baykaner T , Turakhia M , Clopton P L , Chang H J , Brodt C , Narayan S M , Wang P J , Viswanathan M N 
Published: October 2022

Abstract

Background
Several mapping systems are being introduced to guide atrial fibrillation (AF) ablation to patient-specific regions of interest. However, results have been extremely heterogeneous between studies, ranging from very poor to very promising. It is unknown if this reflects specific patient characteristics or procedural factors because most prior series were middle sized (N∼30–100 patients).

Purpose
To study 1 year and 3 year very long-term outcomes from map guided AF-driver ablation in a large patient registry with multiple operators, to identify clinical and procedural features influencing outcomes. In real-world AF patients with diverse comorbidities, we applied a consistent patient-tailored AF mapping and ablation strategy, monitored outcomes carefully and applied statistical and unsupervised machine learning approaches to identify features of success and failure.

Method
We studied 632 consecutive patients (65±10 y, 178 F) undergoing ablation for drug-refractory AF. 59.7% had persistent AF, and 29.9% had prior unsuccessful ablation (median 1 procedure). All patients underwent pulmonary vein isolation (PVI), followed by ablation of AF regions of interest mapped from 64 pole baskets (RhythmView, Abbott, IL), by 11 operators. Patients were followed using ambulatory ECG monitors quarterly for one year, and at the time of symptoms for 3 years.

Results
Fig. 1A shows overall freedom from AF at 1-year of 77.5% (95% CI: 74.2%, 80.9%) and at 3 years of 55.5% (95% CI: 51.2%, 60.1%). Freedom from AF/AT at 1-year was 70.1% (95% CI: 66.5%, 73.8%), and at 3 years was 48.6% (95% CI: 44.3%, 53.3%). Success was higher in patients with procedural termination, first ablation versus prior unsuccessful procedures, for paroxysmal AF than non-paroxysmal AF (1 year: AT/AF freedom 74.9% versus 66.7%, p=0.006), and smaller left atrium. Three clusters (Fig 1B) were identified comprising CHA2DS2VASc score, enlarged LA, prior failed case, presenting rhythm and termination during the procedure (Table 2). At 1 year, freedom from AT/AF was 77.8% (95% CI: 72.2%, 82.1%) for cluster 3 and 56.2% (95% CI: 48.3%, 65.4%) for cluster 1 (Fig. 1B).

Conclusion
In our large registry of N=632 patients undergoing AF-map guided ablations, machine learned clusters identified cohorts with success of 56.2 to 77.8% at 1 year. Future studies should identify if lower success represents technical challenges, such as difficulties in mapping very large atria, or more difficult to treat mechanisms. These results may inform patient inclusion and ablation strategy in upcoming AF treatment trials.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National budget only - NIH, R01 HL149134, R01HL83359
Edoxaban in dialysis: a 4-year follow-up in a single center experience
Authors: Fazio G , Schiro P , Milana G 
Published: October 2022

Abstract

Background
Patients with atrial fibrillation (AF) and advanced chronic kidney disease (CKD) are at high risk of adverse events and are complicated to manage. There is little evidence on the effects of non-vitamin K oral anticoagulants in patients with severe CKD. Preliminary data in patients taking edoxaban whose creatinine clearance fell below 30 mL/min showed a low risk of stroke and major bleeding. The aim of our study is to test the safety of edoxaban 30 mg/day in patients with severe renal impairment with an estimated glomerular filtration rate (eGFR) &lt;15 mL/min in dialisys.

Methods
We analyzed retrospective data from 46 patients who had documented AF with severe renal impairment (eGFR &lt;15 mL/min). The follow-up, characterized by clinical examination and blood analysis, was performed every 6 months. The main endpoint was the incidence of major bleedings or clinically relevant non-major (CRNM) bleedings or thromboembolic events.

Results
All patients included were treated with Edoxaban for atrial fibrillation.
At the time of the data collection, the mean follow-up in valvular patients was 24±2 months. There were no major bleedings, strokes, transitory ischemic event, systemic embolisms, or cardiovascular deaths were been reported. 3 (12.5%) cases of minor bleeding was reported. The complication rate of the patients in dialysis are the same than the atrial fibrillation population without any statistical differences (1.39% vs 1,37%, p: 0.96).

Conclusion
The use of Edoxaban in dialysis and atrial fibrillation seems safe and effective.

Funding Acknowledgement
Type of funding sources: None.
Impact of diabetes and glucose-lowering therapy on post-operative atrial fibrillation after cardiac surgery: secondary analysis of the SEARCH-AF CardioLink-1 randomized clinical trial
Authors: Pandey A , Hibino M , Ha A , Quan A , Verma A , Bisleri A , Mazer C D , Verma S 
Published: October 2022

Abstract

Background
Diabetes mellitus is an important risk factor for atrial fibrillation (AF) and is associated with an increased risk of complications for patients with AF. The impact of diabetes on post-operative AF after cardiac surgery is not well-defined.

Purpose
We sought to characterize the effect of diabetes, insulin, and oral hypoglycemic agents on the incidence of post-operative atrial fibrillation (POAF) after cardiac surgery. Accordingly, we conducted a secondary analysis of the Post-Surgical Enhanced Monitoring for Cardiac Arrhythmias and Atrial Fibrillation (SEARCH-AF) CardioLink-1 randomized trial.

Methods
In the SEARCH-AF trial, 336 patients with risk factors for stroke (CHA2DS2-VASc score ≥2) and no history of preoperative AF were randomized to usual care or continuous cardiac rhythm monitoring for 30 days after discharge from cardiac surgery with a wearable, patched-based device. The primary outcome was occurrence of cumulative atrial fibrillation/flutter (AF/AFL) lasting for ≥6 minutes detected by continuous monitoring or AF/AFL documented by a 12-lead electrocardiogram within 30 days of randomization. We assessed the association between diabetes and occurrence of post-operative AF. In addition, we examined the association between POAF and glucose-lowering therapy among patients with diabetes.

Results
Among the 176 (52%) patients with diabetes in the study cohort, 80 (45%) patients were treated with at least 1 oral hypoglycemic agent and 44 (25%) patients were treated with insulin. The incidence of POAF occurring within 30 days after discharge from surgery was similar between patients with or without diabetes (cumulative incidence: 10.8% vs. 10.0%, log-rank p=0.77). Among patients with diabetes, the incidence of POAF was highest in those who were not treated with glucose-lowering therapy (17.3%) when compared with those treated with oral hypoglycemic agents (10.0%) or insulin (4.5%) (log-rank ptrend=0.045 among the 3 groups). In an exploratory analysis, we observed a trend suggesting a lower incidence of POAF among cardiac surgical patients who were treated with SGLT-2 inhibitors (log-rank ptrend=0.084).

Conclusion
The incidence of POAF occurring after discharge from cardiac surgery is equally high among patients with or without diabetes. Our results suggest a potential association between specific glucose-lowering therapies and risk of POAF after cardiac surgery, meriting further investigations.

Funding Acknowledgement
Type of funding sources: Other. Main funding source(s): Heart and Stroke Foundation of Canada
The Mueller maneuver attenuates left atrial phasic volumes and myocardial strain in healthy younger adults
Authors: Wright S P , Dawkins T G , Harper M I , Shave R , Eves N D 
Published: October 2022

Abstract

Background
Negative intrathoracic pressure swings alter cardiac loading conditions, which may impact left atrial hemodynamic function and augment atrial stress. If such changes occur and are repeated chronically, they may contribute to the marked atrial remodeling seen in states associated with forceful inspiratory efforts such as endurance training or obstructive sleep apnea.

Purpose
We studied the acute effects of static inspiratory efforts on left atrial chamber function, myocardial mechanics, and diastolic function.

Methods
We included healthy adults (10M/7F, 24±4 years) and used Mueller maneuvers to reduce intrathoracic pressure to a −30 cmH2O target for 15 seconds. Over 6 repeated trials, we used echocardiography to acquire left atrial and ventricular focused 2D images, and mitral Doppler inflow and annular tissue velocity spectra. Images were analyzed offline to determine left ventricular volumes, tissue relaxation velocities, trans-mitral filling velocities, and phasic left atrial volumes and myocardial strain using speckle-tracking imaging. Repeated measures were made at Baseline, within the last 5 seconds of the Mueller maneuver, and within the first 5 seconds after release, with 3–5 cardiac cycles averaged per measurement.

Results
Compared to Baseline, hemodynamic changes occurred during the late phase of the Mueller maneuver and immediately after release. Left ventricular stroke volume decreased by −10±4 mL (p&lt;0.05) then returned to baseline upon release; this was associated with a −11±9 mL (p&lt;0.05) reduction in end-diastolic volume. Left ventricular early diastolic filling attenuated, reflected by decreases in mitral annular relaxation velocity (−2±2 cm/s, p&lt;0.05), E-wave filling velocity (−13±14 cm/s, p&lt;0.05), and left atrial passive emptying volume (−5±5 mL, p&lt;0.05), each normalizing upon release. Left atrial maximal volume decreased (−5±5 mL, p&lt;0.05) during the Mueller maneuver, but increased relative to baseline (+4±5 mL, p=0.049) following release, while left atrial peak positive longitudinal strain decreased (−6±6%, p&lt;0.05) and normalized upon release.

Conclusions
Attenuated left atrial and in turn ventricular filling may contribute to acute stroke volume reduction during forceful inspiratory efforts. Rapid changes in left atrial chamber volumes and myocardial strain with the release of forceful inspiratory efforts may reflect acute left atrial stress.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Natural Sciences and Engineering Research Council Discovery Grant
Elevated thrombin generation levels in the left atrial appendage in patients with atrial fibrillation
Authors: Elias A , Khoury Y , Shehadeh F , Ron G , Boulos M , Zukermann R , Elias M , Gepstein L , Suleiman M 
Published: October 2022

Abstract

Introduction
Atrial Fibrillation (AF) is the most common sustained arrhythmia. Thrombus formation in the left atrial appendage (LAA) increases the risk for stroke and systemic embolism in AF patients. The proposed mechanisms for thrombus formation in the LAA are stasis, endothelial dysfunction and local hypercoagulability. The aim of this study was to compare thrombin generation potential in various heart chambers among AF patients.

Material and methods
A prospective cross-sectional study of 47 patients with AF undergoing pulmonary vein isolation (PVI). Blood samples from the femoral vein (FV), right atrium (RA), left atrium (LA) and LAA were collected during the PVI procedures. The Samples were collected before heparin administration. Thrombin generation was assessed by the calibrated automated thrombogram (CAT).

Results
A total of 47 patients (36.2% female, mean age 58.7±13, 59.6% with CHADS-VASc ≥2) were enrolled into the study. The mean endogenous thrombin potentials (ETP) were 1580±558, 1433±540, 1141±611 and 1487±760 in the FV, RA, LA and LAA, respectively (P&lt;0.05). The mean thrombin peak heights were 244±124, 199±102, 139±94 and 195±129 in the FV, RA, LA and LAA, respectively (P&lt;0.05).
A post-hoc pairwise comparison demonstrated elevated thrombin generation in the LAA compared to the LA (P=0.014). Furthermore, LA thrombin generation levels were significantly lower from the FV and RA (P&lt;0.05).

Conclusion
In patients with AF, the LAA has increased thrombotic potential compared to the LA. These findings might explain why the LAA is more predisposed to thrombus formation than the LA.

Funding Acknowledgement
Type of funding sources: None.