bluuebunny/crossref_metadata_2025_split huggingface dataset:
Treatment of cryptogenicstroke patients with atrial fibrillation detected by insertable cardiac monitors reduces recurrent stroke risk to background levels
Authors: Kloosterman E , Rosenbaum M.R , Berkowitz E.J.B , Kloosterman N.K , Rosman J , Wettenstein Z.W 
Published: November 2020

Abstract

Background
Atrial fibrillation (AF) is a well-known risk factor for ischemic stroke with a reported increased incidence range of 2.5 to 5-fold. However, it is not well established whether treatment of cryptogenic stroke patients with AF detected by insertable cardiac monitors (ICM) reduces the risk of recurrent stroke.

Objective
To compare recurrent stroke rates between cryptogenic stroke patients who have AF detected by ICMs and thus started on oral anticoagulation (OAC) treatment and those without detected AF.

Methods
We performed a retrospective analysis of consecutive patients who received an ICM for the purpose of AF monitoring following a cryptogenic stroke between July 2015 and March 2019. Patients with prior documented AF history were excluded. We calculated the rates of AF detection and OAC initiation. We also compared recurrent stroke rates between patients with and without AF detected.

Results
A total of 298 cryptogenic stroke patients receiving an ICM and home remote monitoring were studied (mean age: 77 SD: 11.7; Female/Male: 147 (49%)/151; virtual CHA2DS2-VASc: 4.96 SD: 1.28). AF was newly detected in 91 (29.6%) patients over a mean follow-up of 46 months. Of these patients 68 (72.4%) were started on OAC, 12 (15.3%) were already on OAC and 11 (12.2%) remained not anticoagulated. Of the total patients evaluated, 22 patients (7.3%) developed recurrent strokes for an annualized stroke rate of 1.926%. Of those, 8 occurred among the 91 patients with newly detected AF, for an annualized stroke rate of 1.72%. The remining 14 recurrent strokes occurred among the 207 patients without AF detected, for an annualized stroke rate of 1.76%; (p=0.87). One recurrent stroke occurred in an AF patient not anticoagulated due to a prior bleeding event. No hemorrhagic strokes were reported in the AF-OAC group.

Conclusion
Our study found that newly AF was detected by ICM in almost 1/3 (29%) of cryptogenic stroke patients (consistent with previous studies), and the vast majority of them (88%) accordingly received oral anticoagulation. There was not a significant difference in recurrent stroke rates among patients with AF detected on OAC and those without AF detected. This suggests that rigorous arrhythmia monitoring with ICMs can help identify cryptogenic stroke patients with new AF and initiate oral anticoagulation accordingly, to reduce their risk of recurrent stroke to background levels.
Annualized Stroke Risk

Funding Acknowledgement
Type of funding source: None
10-year trend analysis of atrioventricular node ablation in patient with atrial fibrillation: 2005–2014 United State hospitalization
Authors: Wu L , Narasimhan B , Shah A.N , Zheng Y.Y , Bhatia K , Kantharia B 
Published: November 2020

Abstract

Introduction
Atrial fibrillation (AF) ablation and Atrioventricular Node (AVN) ablation are both important non-pharmacological therapy of AF. In spite of increased availability of AF ablation data, that of AVN ablation per se is limited.

Method
AF ablation was identified using ICD-9 procedure code with principle diagnosis of AF from United States National Inpatient Sample database 2005–2014. From procedure and diagnosis codes of pacemaker insertion followed by ablation, the cohort who underwent AVN ablation was identified. Patients hospitalization with any diagnosis of other type of arrythmia or epicardial ablation were excluded. Complications were defined as per the Agency for Health Care Research and Quality guideline.

Results
Total AF ablation was noted to increase from 2005- 2011, and declined steadily from 2011–2014. In contrast, the number of AVN ablations increased from 4505 cases to 5175 (Figure 1). AVN ablation were mainly performed in elderly patient (mean age 72), and increasingly in patient with higher Charlson Commobidity index (0.9 to 1.7)and higher CHA2DS2-VASc score (2.8 to 3.7) (Table 1). An increasing trend in procedure complications but no significant change in mortalitywere observed with AVN ablation. Progressive increase in the length of stay and the hospitalization cost were also observed over the years with AVN ablation.

Conclusion
AVN ablation is being performed at a steady volume, and increasingly in patients with multiple comorbidities. This trend although was not associated with increased mortality, it was associated with increased hospital complications.

Funding Acknowledgement
Type of funding source: None
Is higher power shorter duration radiofrequency energy is better than lower power longer duration strategy in catheter ablation of atrial fibrillation A meta-analysis
Authors: Khanra D , Aggarwal P , Kumar H , Mishra V , Jain B , Reddy K.K 
Published: November 2020

Abstract

Background
An ideal strategy for radiofrequency ablation (RFA) of atrial fibrillation (AF) in the left atrium should be efficient enough to achieve transmural lesions in left atrium with no or minimal collateral tissue damage. Resistive heating of high power short duration (HPSD) RFA has been found to result in lesions larger in width but lesser in depth compared to lower power longer duration (LPLD) RFA in some experimental studies.

Purpose
This meta-analysis was performed to compare procedural, short-term and long-term outcomes of HPSD versus LPLD RFA of AF.

Methods
PubMed, Embase and Cochrane databases were systematically reviewed. Five observational studies meeting criteria were included in the meta-analysis. All the studies scored six or more points in the New-castle Ottawa scale. There were considerable variations in the ablation strategies across the studies. However, radiofrequency power more than 40W was considered as high power. Hypergeometric model with exact likelihood function was utilized for statistical analysis.

Results
Baseline parameters and ablation details have been depicted in Table 1. 740 patients with HPSD and 287 patients with LPLD ablation strategies, were followed up from 6 to 30 months. Total procedural time (P value &lt;0.0001) and ablation time (P value &lt;0.0001) were significantly lower in the HPSD group than LPLD group. However, the fluoroscopy time was similar (P value = 0.09) in both the groups (Table 2). There were no occurrences of atrio-esophageal fistula or pulmonary venous stenosis in any of the studies. Cardiac tamponade (P value = 0.56), stroke (P value = 0.70) and AF recurrences (P value = 0.81), were similar in both groups (Table 2).

Conclusion
Newer HPSD and conventional LPLD RFA, both the strategies are very safe procedure for treatment of RFA with low to no procedural complications. AF recurrence rates were reasonably high irrespective of ablation strategies, however, no strategy scored statistically better over the other one. Large randomized multi-centric studies with long-term follow up are needed to test the theoretical advantage of HPSD ablation over the traditional ablation strategy of AF.

Funding Acknowledgement
Type of funding source: None
A machine-learning algorithm to predict atrial fibrillation recurrence after a pulmonary vein isolation procedure
Authors: Nascimento Matos D , Ferreira A.M , Sousa A , Rodrigues G , Carmo J , Freitas P , Guerreiro S , Abecasis J , Costa F , Carmo P , Saraiva C , Cavaco D , Morgado F , Mendes M , Adragao P 
Published: November 2020

Abstract

Background
Contemporary risk models to predict the recurrence of atrial fibrillation (AF) after pulmonary vein isolation have limited predictive ability. Models with high specificity seem particularly suited for the setting of AF ablation, where they could be used as gatekeepers to withhold intervention in patients with low likelihood of success. Machine learning (ML) has the potential to identify complex nonlinear patterns within datasets, improving the predictive power of models. This study sought to determine whether ML can be used to better identify patients who will relapse within one year of an AF ablation procedure.

Methods
We assessed 484 patients (294 men, mean age 61±12 years, 76% with paroxysmal AF) who underwent radiofrequency pulmonary vein isolation (PVI) for symptomatic drug-refractory AF. Using this dataset, a machine-learning model based on Support Vector Machines (SVM) was developed to predict AF recurrence within one year of the procedure. The following variables were used to feed the model: type of AF (paroxysmal vs. non-paroxysmal), previous ablation procedure, left atrium (LA) volume, and epicardial fat volume (both derived from pre-ablation cardiac CT). The algorithm was trained in a random sample of 70% of the study population (n=339) and tested in the remainder 30% (n=145).

Results
A total of 130 patients (27%) suffered AF recurrence within one year of the procedure. The ML model predicted AF recurrence with 75% accuracy (95% CI 67–82%), yielding a sensitivity and specificity of 25% (95% CI 13–41%) and 94% (95% CI 88–98%), respectively. The corresponding positive and negative predictive values were 62% (95% CI 39–81%) and 77% (95% CI 67–82%), respectively. The relative weight of the variables in the ML model was: epicardial fat 56%, type of AF 23%, previous ablation 14%, and LA volume 7%. A high-risk subgroup representing 10.8% of patients was identified with the ML algorithm. In this subgroup, one-year recurrence was 62%, representing 24% of the total number of recurrences.

Conclusion
A machine-learning model showed high specificity in the identification of patients who relapse during the first year after AF ablation. In the future, these tools may be useful to improve patient selection.

Funding Acknowledgement
Type of funding source: None
Catheter ablation in atrial fibrillation: comorbidities and mortality from high-volume centers
Authors: Sousa J , Carmo J , Matos D , Rodrigues G , Ferreira A , Alencar J , Klemtz F , Durazzo A , Carvalho S , Costa F.M , Carmo P , Parreira L , Morgado F , Cavaco D , Adragao P 
Published: November 2020

Abstract

Background
Catheter ablation (CA), has gained wider acceptance as an attractive option for treating symptomatic AF. Although traditionally seen as a safe procedure, there is limited and conflicting data on procedure-related early morbimortality, with new evidence suggesting early mortality may be as high as 0.5%-1%.

Purpose
We aimed to assess the rates of early and late morbimortality of post-atrial fibrillation (AF) ablation in high-volume centers.

Methods
Prospective registry of 2 high-volume ablation centers, comprising 3722 consecutive patients (mean age 61.1±11.2, 66.4% male, n=2471), who underwent AF ablation from 2005 to 2019. Early mortality was defined as death during initial admission or during the first 45 days after ablation. Median follow-up time was 5.4 years.

Results
Most patients were treated with radiofrequency (97%) while 3% were treated with cryoablation. Early mortality was 0.08% (n=3), with a median time from ablation to death of 22 days. Cumulative mortality at 3, 6 and 12 months was 0.08%, 0.16% and 0.19%, respectively. At 3 and 5 years, mortality remained low at 0.48% and 0.73%, respectively. Early mortality was higher among patients who had suffered procedural complications (fistula and stroke, p&lt;0.001). Among the latter, pericardial effusion and tamponade were the most frequently found (0.6%, n=24), only 1 of which required emergent surgical drainage and myocardial repair. Early ischemic stroke occurred in 2 patients (0.1%). Other less frequent complications were atrio-esophageal fistula (0.1%, n=2), phrenic nerve palsy (0.1%, n=2), anoxic encephalopathy following cardiac arrest (0.03%, n=1) and pulmonary vein stenosis (0.03%, n=1).

Conclusion
Early mortality following ablation is very low (&lt;0.1%), when performed by an experienced high-volume team. Severe complications are rare (&lt;1%) and mostly amenable to treatment. Our findings reaffirm the overall safety of AF ablation.
AF catheter ablation morbimort

Funding Acknowledgement
Type of funding source: None
Pulmonary vein isolation procedure may be associated with intracranial artery microembolism and increased risk of acute neurological incidents
Authors: Lasek-Bal A , Puz P , Wieczorek J , Nowak S , Wnuk-Wojnar A.M , Warsz-Wianecka A , Mizia-Stec K 
Published: November 2020

Abstract

Background
Atrial fibrillation ablation can be associated with the microembolism detected in intracranial arteries and risk of acute neurological incidents.

Purpose
The aims of this study were a quantitative and a qualitative evaluation of microembolic signals (MES) during pulmonary vein isolation (PVI) and establishing the potential significance of MES for damage of brain assessed in radiological investigation and neurological state of patients.

Methods
To the prospective project we qualified patients with atrial fibrillation undergoing percutaneous pulmonary vein isolation (radiofrequency ablation / balloon cryoablation) with ultrasound monitoring of microembolisms in right middle cerebral artery. Baseline and up to 12 months post pulmonary vein isolation the neurological examination and brain MRI were performed in all participants.

Results
The study enrolled 80 patients at a mean age of 58 years. Microembolisms during the monitoring of the flow in the right middle cerebral artery were recorded in 61 (76.3%) patients in the amount of 51–489 (mean 239). Most often the microembolic signals were registered during the trans-septal puncture and the stage of ablation. In 89%, microembolisms were gaseous. Mean score on Fazekas scale for the whole group before ablation: 0.87±0.7 (0–3, med. 1); after: 0.93±0.71. In 3 (4.3%) patients the lesions worsened during the follow-up period. None of the patients revealed a cardiovascular event during the follow-up period and no changes were observed in the neurological status.

Conclusions
The majority of cerebral microembolism generated during PVI are gaseous in nature. The cerebral microembolism associated with PVI probably result from the technical aspects of the procedure and do not cause neither the permanent brain damage in the radiological investigation nor neurological deficit.

Funding Acknowledgement
Type of funding source: Public Institution(s). Main funding source(s): Medical University of Silesia, Katowice, Poland - statutory work
Electrical posterior box isolation in persistent atrial fibrillation changed to paroxysmal atrial fibrillation: a multi-center, prospective, randomized study
Authors: Pak H.N , Park J.B , Yu H.T , Kim T.H , Uhm J.S , Joung B.Y , Lee M.H , Kim Y.H , Shim J.M 
Published: November 2020

Abstract

Background
Persistent atrial fibrillation (PeAF) can change to paroxysmal AF (PAF) after antiarrhythmic drug medication and cardioversion.

Purpose
We investigated whether electrical posterior box isolation (POBI) may improve rhythm outcome of catheter ablation in those patient group.

Methods
We prospectively randomized 114 patients with PeAF to PAF (male 75%, 59.8±9.9 years old) to circumferential pulmonary vein isolation (CPVI) alone group (n=57) and additional POBI group (n=57). The primary end-point was AF recurrence after a single procedure, and the secondary end-point was a recurrence pattern, cardioversion rate, and the response to antiarrhythmic drugs (AADs).

Results
After a mean follow-up of 22.5±9.4 months, the clinical recurrence rate did not significantly differ between the two groups (29.8% vs. 28.1%, p=0.836; log rank p=0.815) The recurrence rate for atrial tachycardias (17.6% vs. 43.8%, p=0.141) was higher in POBI group, but the cardioversion rates (13.5% vs. 8.5%, p=0.434) were not significantly different between two groups. At the final follow-up, sinus rhythm was maintained without antiarrhythmic drug in 52.6% in CPVI group and 59.7% of POBI group (p=0.452). No significant difference was found in the major complication rates between the two groups (5.3% vs. 1.8%, p=0.618), but the total ablation time was significantly longer in the POBI group (4397±842 sec vs. 5337±1517 sec, p&lt;0.001).

Conclusion
In patients with persistent AF converted to paroxysmal AF by AAD, the addition of POBI to CPVI did not improve the rhythm outcome of catheter ablation nor influence overall safety.

Funding Acknowledgement
Type of funding source: None
The outcome of ablation for non-paroxysmal atrial fibrillation targeting spatiotemporal electrogram dispersion compared with ganglionated plexi ablation
Authors: Sakata K , Tanaka T , Yamashita S , Yamashiro K 
Published: November 2020

Abstract

Background
Although catheter ablation targeting ganglionated plexi (GP) playing an important role in formation of triggers and substrates of atrial fibrillation (AF) has been reported as one of the effective ablation strategies in non-paroxysmal AF (non-PAF) patients, its effectiveness varies among the study groups. More recently, ablation targeting spatiotemporal electrogram dispersion (STED) areas, assumed to contain AF drivers in forms of rotational activation is proposed. However, the optimal ablation strategy for non-PAF is still controversial since the exact mechanisms of non-PAF are not well understood.

Purpose
To investigate the effectiveness of GP ablation for autonomic modification and STED ablation for modulation of AF drivers.

Methods
Consecutive 149 non-PAF patients who underwent STED ablation in our center were enrolled. We detected STED areas within the whole left and right atrium during AF using PentaRay®, and ablated them. If AF was terminated during STED ablation, we finished the procedure without burning the remaining STED areas. If not, electrical cardioversion was applied. The outcome was compared with that in consecutive 156 non-PAF patients undergoing GP ablation previously in our center.

Results
(1) The clinical characteristics were comparable between two groups (see Table). (2) A Kaplan-Meier curve showed that there was no significant difference between the freedom rates from non-PAF/non-paroxysmal atrial tachycardia (non-PAT) after single procedure in STED group and GP group (Figure, left). (3) However, the freedom rates from non-PAT in STED group was significantly lower than that GP group (Figure, right).

Conclusions
The recurrence type of atrial arrhythmia after ablation was remarkably different between ablation of STED and GP. STED ablation might eliminate fibrillatory conduction and control AF driver in patients with non-PAF.
Freedom from atrial arrhythmia

Funding Acknowledgement
Type of funding source: None
Complete transmural epicardial ablation reduces organized areas in atrial fibrillation
Authors: Rogers A , Ravi N , Bhatia N.K , Shah R.L , Pong T , Tung J.S , Purewal S , Baykaner T , Rappel W.J , Brodt C.R , Wang P.J , Lee A , Narayan S.M 
Published: November 2020

Abstract

Background
The surgical maze is suggested to be effective in persistent atrial fibrillation (AF) by reducing the area for fibrillatory wavelets. However, the mechanism for recurrence and next treatment steps are unclear.

Purpose
We set out to evaluate the impact of complete transmural epicardial maze lesion sets on the extent atrial organization using novel analyses of wide-area recordings of AF.

Methods
19 patients (age 50.9±12.0, 78% male) underwent maze followed by endocardial mapping of AF with a 64-pole basket catheter. Block across roof, floor, and pulmonary vein lesions sets was assessed by high-density voltage mapping and organized zones of AF were assessed by panoramic recordings. Total organized area and mean area of the dominant site were evaluated using automated custom scripts.

Results
Patients had 3.2±0.9 organized regions in 1 minute of LA recordings. A 54 yo F showed residual conduction to the posterior wall from the roof (purple, Fig. 1A) and a figure-of-8 propagation pattern during AF (arrows, fig B) which terminated with localized ablation (yellow lesions, Fig. 1A, red X, Fig. 1B). Overall, patients with complete block on epicardial lesion set had smaller areas of organization (13.7±8% vs. 45.7±32% of mapped areas, p=0.029) vs. those with gaps. The average size of the dominant area was smaller with complete transmural lines than with gaps (5.7±3% vs. 15.9±10%, p=0.033) (Fig. 1C).

Conclusion
These results show that complete transmural lesion sets constrain the critical mass available for AF, with smaller resulting organized zones. Future studies that quantify how partitioning the atrial surface affects AF may help personalize lesion sets after maze.
Figure 1

Funding Acknowledgement
Type of funding source: Public grant(s) – National budget only. Main funding source(s): NIH NRSA F32 United States
Motivational Interviewing to Support Oral AntiCoagulation adherence in patients with non-valvular Atrial Fibrillation (MISOAC-AF): a randomised clinical trial
Authors: Tzikas A , Samaras A , Kartas A , Vasdeki D , Fotos G , Dividis G , Paschou E , Forozidou E , Tsoukra P , Kotsi E , Goulas I , Karvounis H , Giannakoulas G 
Published: November 2020

Abstract

Background
Oral anticoagulation (OAC) is paramount to effective thromboprophylaxis; yet adherence to OAC remains largely suboptimal in patients with atrial fibrillation (AF).

Purpose
We aimed to assess the impact of an educational, motivational intervention on the adherence to OAC in patients with non-valvular AF.

Methods
Hospitalised patients with non-valvular AF who received OAC were randomly assigned to usual medical care or a proactive intervention, comprising motivational interviewing and tailored counseling on medication adherence. The primary study outcome was adherence to OAC at 1-year, evaluated as Proportion of Days Covered (PDC) by OAC regimens and assessed through nationwide prescription registers. Secondary outcomes included the rate of persistence to OAC, gaps in treatment, proportion of VKA-takers with labile INR (defined as time to therapeutic range&lt;70%) and clinical events.

Results
A total of 1009 patients were randomised, 500 in the intervention group and 509 in the control group. At 1-year follow-up, 77.2% (386/500) of patients in the intervention group had good adherence (PDC&gt;80%), compared with 55% (280/509) in the control group (adjusted odds ratio 2.84, 95% confidence interval 2.14–3.75; p&lt;0.001). Mean PDC±SD was 0.85±0.26 and 0.75±0.31, respectively (p&lt;0.001). Patients that received the intervention were more likely to persist in their OAC therapy at 1 year, while usual medical care was associated with more major (≥3 months) treatment gaps [Figure]. Among 212 VKA-takers, patients in the intervention group were less likely to have labile INR compared with those in the control group [21/120 (17.1%) vs 34/92 (37.1%), OR 0.33 95% CI 1.15–0.72, p=0.005]. Clinical events over a median follow-up period of 2 years occurred at a numerically lower, yet non-significant, rate in the intervention group [Table].

Conclusions
In patients receiving OAC therapy for non-valvular AF, a motivational intervention significantly improved patterns of medication adherence, without significantly affecting clinical outcomes.
Primary and secondary outcomes

Funding Acknowledgement
Type of funding source: None