Topic: Electrophysiology

Abstract

Reproducibility of Clinical Late Gadolinium Enhancement Magnetic Resonance Imaging in Detecting Left Atrial Scar after Atrial Fibrillation Ablation.

Kamali R, Schroeder J, DiBella E, Steinberg B, ... Macleod RS, Ranjan R
Background
Late gadolinium enhancement (LGE) cardiac MRI can be used to detect post-ablation atrial scar (PAAS) but its reproducibility and reliability in clinical scans across different magnetic flux densities and scar detection methods is unknown.
Methods
Patients (n=45) having undergone two consecutive MRIs (three months apart) on 3T and 1.5T scanners were studied. We compared PAAS detection reproducibility using four methods of thresholding: simple thresholding, Otsu thresholding, 3.3 standard deviations (SD) above blood pool (BP) mean intensity, and image intensity ratio (IIR). We performed a texture study by dividing the left atrial wall intensity histogram into deciles and evaluated the correlation of the same decile of the two scans as well as to a randomized distribution of intensities, quantified using Dice Similarity Coefficient (DSC).
Results
The choice of scanner did not significantly affect the reproducibility. The scar detection performed by Otsu thresholding (DSC of 71.26±8.34) resulted in better correlation of the two scans compared to the methods of 3.3 SD above BP mean intensity (DSC of 57.78±21.2, p<0.001) and IIR above 1.61 (DSC of 45.76±29.55, p<001). Texture analysis showed that correlation only for voxels with intensities in deciles above the 70 percentile of wall intensity histogram was better than random distribution (p<0.001).
Conclusions
Our results demonstrate that clinical LGE-MRI can be reliably used for visualizing PAAS across different magnetic flux densities if the threshold is greater than 70 percentile of the wall intensity distribution. Also, atrial wall based thresholding is better than BP based thresholding for reproducible PAAS detection. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 14 Sep 2020; epub ahead of print
Kamali R, Schroeder J, DiBella E, Steinberg B, ... Macleod RS, Ranjan R
J Cardiovasc Electrophysiol: 14 Sep 2020; epub ahead of print | PMID: 32931635
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Abstract

Recovery of atrial contractile function after cut-and-sew maze for long-standing persistent valvular atrial fibrillation.

Jin Y, Wang HS, Han JS, Zhang J, ... Yu Y, Zhao Y
Objective
The recovery of atrial contractile (AC) after maze has been concerned and even questioned. Now, studied the AC recovery degree and its influencing factors .
Method
237 patients with valvular long-standing persistent atrial fibrillation (AF) were retrospectively grouped according to whether sinus rhythm(SR) maintained and AC restored: SR-AC (163 cases), SR-no-AC (41 cases) and AF-no-AC (33 cases). SR-AC were grouped according to Em/Am ratio. Em/Am≤2 showed that the AC recovered well.
Results
The SR maintained rate (161/177, 90.96%) in patients underwent the cut-and-sew maze III (CSM) was significantly higher than that in cryoablation (43/60, 71.7%). Preoperative AF duration had no significant difference among three groups (P = 0.679). Maze methods had significant relationship with whether SR recovered, P < 0.05, but no significant relationship with whether AC recovered in SR maintained patients (P = 0.280). Nearly 80% (163/204) patients can recover AC, among 156 patients (156/204, 76.5%) recovered contractile of left and right atrium, and 63 (63/204, 30.1%) recovered significant left atrial contractile, that is, Em/Am≤2. Whether AC was significantly restored was not related to maze methods, P = 0.370. AC recovered degree in rheumatic heart disease (RHD) patients was worse than that in mitral valve prolapse (MVP) patients, P = 0.004.
Conclusion
To sum up, the CSM is safe and effective, and the atrial contractile function recovery was found in 80%. The key to the success of maze is to form a complete and lasting electrical isolation, and there was no difference in the rate of atrial contractile recovery when postoperative SR was maintained, no matter what maze method is used. MVP patients should be treated with maze more actively than RHD patients.

Copyright © 2020. Published by Elsevier B.V.

Int J Cardiol: 09 Sep 2020; epub ahead of print
Jin Y, Wang HS, Han JS, Zhang J, ... Yu Y, Zhao Y
Int J Cardiol: 09 Sep 2020; epub ahead of print | PMID: 32920067
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Abstract

Machine learning does not improve upon traditional regression in predicting outcomes in atrial fibrillation: an analysis of the ORBIT-AF and GARFIELD-AF registries.

Loring Z, Mehrotra S, Piccini JP, Camm J, ... Pieper K, Kakkar AK
Aims
Prediction models for outcomes in atrial fibrillation (AF) are used to guide treatment. While regression models have been the analytic standard for prediction modelling, machine learning (ML) has been promoted as a potentially superior methodology. We compared the performance of ML and regression models in predicting outcomes in AF patients.
Methods and results
The Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) and Global Anticoagulant Registry in the FIELD (GARFIELD-AF) are population-based registries that include 74 792 AF patients. Models were generated from potential predictors using stepwise logistic regression (STEP), random forests (RF), gradient boosting (GB), and two neural networks (NNs). Discriminatory power was highest for death [STEP area under the curve (AUC) = 0.80 in ORBIT-AF, 0.75 in GARFIELD-AF] and lowest for stroke in all models (STEP AUC = 0.67 in ORBIT-AF, 0.66 in GARFIELD-AF). The discriminatory power of the ML models was similar or lower than the STEP models for most outcomes. The GB model had a higher AUC than STEP for death in GARFIELD-AF (0.76 vs. 0.75), but only nominally, and both performed similarly in ORBIT-AF. The multilayer NN had the lowest discriminatory power for all outcomes. The calibration of the STEP modelswere more aligned with the observed events for all outcomes. In the cross-registry models, the discriminatory power of the ML models was similar or lower than the STEP for most cases.
Conclusion
When developed from two large, community-based AF registries, ML techniques did not improve prediction modelling of death, major bleeding, or stroke.

Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: [email protected]

Europace: 02 Sep 2020; epub ahead of print
Loring Z, Mehrotra S, Piccini JP, Camm J, ... Pieper K, Kakkar AK
Europace: 02 Sep 2020; epub ahead of print | PMID: 32879969
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Abstract

Outcomes of ablation in Wolff-Parkinson-White-syndrome: Data from the German Ablation Registry.

Brado J, Hochadel M, Senges J, Kuck KH, ... Kääb S, Sinner MF
Aims
Catheter ablation is recommended for symptomatic WPW-syndrome. Commonly perceived low recurrence rates were challenged recently. We sought to identify patient strata at increased risk.
Method
Of 12,566 patients enrolled at 52 German Ablation Registry sites from 2007 to 2010, 789 were treated for WPW-syndrome. Patients were included for symptomatic palpitations and tachycardia documentation. Follow-up duration was one year. Overall complications were defined as serious, access-related, and ablation-related. We adjudicated WPW-recurrence for re-ablation during follow-up. Risk strata included: admission for repeat ablation at registry entry; accessory pathway localization; antiarrhythmic medical treatment before the ablation.
Results
WPW-syndrome patients were 42.8 ± 16.2 years on average; 39.9% were women. A majority of 95.9% was symptomatic; in 84.4%, a tachycardia was documented. Seventy-six (9.6%) patients presented for repeat procedures. Accessory pathways were located in the left atrium (71.4%), right atrium (21.1%), septum (4.4%), or coronary sinus diverticula (2.1%). Prior antiarrhythmic medication was used in 43.7% of patients. No serious events occurred. The overall complication rate was 2.5% (ablation related 1.2%, access-related 1.3%). Major determinants for complications were presentation for re-ablation as registry index procedure (6.9% vs 2.2%; p = 0.016) and septal pathway location (left 2.0% vs septal 9.1%, p = 0.014). The overall re-ablation rate was 9.7%. Usage of prior antiarrhythmic medication was associated with higher recurrence rates (12.2% vs. 7.6%; p = 0.035).
Conclusions
Patients at higher complication risk may be identified by repeat procedure and septal pathway location. Prior antiarrhythmic medication was associated with higher recurrence rates. Our findings may help improving peri-procedural patient management and information.

Copyright © 2020. Published by Elsevier B.V.

Int J Cardiol: 01 Sep 2020; epub ahead of print
Brado J, Hochadel M, Senges J, Kuck KH, ... Kääb S, Sinner MF
Int J Cardiol: 01 Sep 2020; epub ahead of print | PMID: 32890614
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Abstract

Predicting need for pacemaker implantation early and late after transcatheter aortic valve implantation.

Mazzella AJ, Sanders M, Yang H, Li Q, Vavalle JP, Gehi A
Objectives
To identify associations with either early or late permanent pacemaker (PPM) implantation after transcatheter aortic valve replacement (TAVR) in order to develop an easily interpretable management algorithm.
Background
Injury to the conduction system after TAVR occasionally requires PPM. There is limited data on how to identify which patients will require PPM, particularly after discharge from index hospitalization after TAVR.
Methods
All patients having undergone TAVR at the University of North Carolina through August 2019 were identified and records were manually reviewed. Multivariable analyses were performed to identify associations with post-TAVR PPM due to high-degree atrioventricular block (HAVB). Comparisons were made between patients with no PPM (n = 304) and PPM required, stratified into early (during index hospitalization, n = 32) and late (during subsequent hospitalization, n = 11) PPM cohorts.
Results
Of the 347 patents included for analysis, 43 (12.4%) underwent post-TAVR PPM. In multivariable regression models, early PPM was associated with baseline bifascicular block (OR: 42.16; p < .001), requiring any pacing on first post-TAVR electrocardiogram (ECG) (OR: 31.55; p < .001), and valve oversizing >15% (OR: 3.61; p < .05). Late PPM was associated with baseline right bundle branch block (RBBB) (OR 12.62; p < .001) and history of atrial fibrillation/flutter (OR 4.83; p < .05).
Conclusions
Bifascicular block, any pacing on first post-TAVR ECG, and >15% valve oversizing are associated with early PPM, while RBBB and history of atrial fibrillation/flutter are associated with late PPM. We suggest a management strategy for post-TAVR surveillance and management of HAVB.

© 2020 Wiley Periodicals LLC.

Catheter Cardiovasc Interv: 27 Aug 2020; epub ahead of print
Mazzella AJ, Sanders M, Yang H, Li Q, Vavalle JP, Gehi A
Catheter Cardiovasc Interv: 27 Aug 2020; epub ahead of print | PMID: 32857905
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Abstract

Management and Outcomes of Transvenous Pacing Leads in Patients Undergoing Transcatheter Tricuspid Valve Replacement.

Anderson JH, McElhinney DB, Aboulhosn J, Zhang Y, ... Cabalka AK,
Objectives
The aim of this study was to determine the prevalence of pacemaker lead-related complications following transcatheter tricuspid valve replacement (TTVR).
Background
The rate of permanent pacemaker implantation following tricuspid valve (TV) surgery is high, and many patients have transvenous leads. The feasibility, safety, and outcomes of subsequently performing TTVR in the setting of transvenous pacemaker leads have not been established.
Methods
The VIVID (Valve-in-Valve International Database) registry was used to review 329 patients who underwent TTVR following TV repair or replacement. Patients were subdivided into 3 cohorts for intergroup comparisons: no lead, epicardial lead, and transvenous lead (entrapped or not entrapped during the TTVR procedure).
Results
Of 329 patients who underwent TTVR, 128 (39%) had prior pacing systems in place, 70 with epicardial and 58 with transvenous leads. A total of 31 patients had leads passing through the TV. Three patients had the right ventricular (RV) lead extracted prior to TTVR. The remaining 28 patients had the RV lead entrapped between the transcatheter TV implant and the surgical valve (n = 22) or the repaired TV (n = 6). One patient had displacement of the RV lead during the procedure, and 2 experienced lead failure during follow-up. Overall, there was no significant difference in the cumulative incidences of competing outcomes (death, TV reintervention, TV dysfunction) between patients with and those without pacing leads or entrapped RV leads.
Conclusions
TTVR in the setting of trans-TV pacemaker leads without lead extraction or re-replacement can be performed safely with a low risk for complications, offering an alternative to surgical TV replacement.

Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

JACC Cardiovasc Interv: 07 Aug 2020; epub ahead of print
Anderson JH, McElhinney DB, Aboulhosn J, Zhang Y, ... Cabalka AK,
JACC Cardiovasc Interv: 07 Aug 2020; epub ahead of print | PMID: 32800497
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Abstract

Kidney function and the risk of heart failure in patients with new-onset atrial fibrillation.

Carrero JJ, Trevisan M, Evans M, Svennberg E, Szummer K
Aims
Heart failure (HF) is the most common complication of patients with atrial fibrillation (AF), but possible risk factors or health consequences are not well described. Low kidney function is a risk factor for both AF and HF. We evaluated estimated glomerular filtration rate (eGFR) as a predictor of HF in patients with AF, and then quantified the adverse health outcomes associated to incident HF.
Methods and results
This is an observational analysis of 19,662 adults without a previous history of HF who had new-onset AF in Stockholm healthcare (Sweden) during 2007-2011. During a median of 713 (IQR 281-1253) days of follow up, 3342 (16.4%) patients developed HF, with incidence rate of 7.4 per 100-person-years (95% CI 7.2-7.7). In Cox regression, eGFR was linearly associated with subsequent HF risk. Compared to eGFR≥60 ml/min/1.73 m, patients with eGFR 30-59 and eGFR<30 ml/min/1.73 m had 13% (HR 1.13; 95% CI 1.04-1.23) and 53% (HR 1.53; 1.25-1.88) higher risk of HF. Results were consistent across various pre-specified subgroups and after excluding early events. Compared to non-HF, developing HF (as a time-varying exposure) was associated with a 5-fold (HR 5.05; 4.07-6.28) higher risk of subsequent kidney function decline, a 1.5 times higher risk of stroke (HR 1.54; 1.35-1.76), and a doubling in the risk of myocardial infarction (HR 2.21; 1.87-2.62) and death (HR 2.17; 2.01-2.33).
Conclusion
In patients with AF, low kidney function associates with the risk of HF. Developing HF heightened the subsequent risk of kidney function decline, cardiovascular event and death.

Copyright © 2020. Published by Elsevier B.V.

Int J Cardiol: 04 Aug 2020; epub ahead of print
Carrero JJ, Trevisan M, Evans M, Svennberg E, Szummer K
Int J Cardiol: 04 Aug 2020; epub ahead of print | PMID: 32768410
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Abstract

The increased risk of bleeding due to drug-drug interactions in patients administered direct oral anticoagulants.

Lee JY, Oh IY, Lee JH, Kim SY, ... Kim YK, Bang SM
Introduction
Direct oral anticoagulants (DOACs) have the potential to increase bleeding due to drug-drug interactions (DDIs). In the present study, the risk of bleeding was evaluated when drugs with potential DDIs were simultaneously prescribed with DOACs.
Materials and methods
The present study included patients with non-valvular atrial fibrillation (AF) and venous thromboembolism (VTE) who were newly prescribed DOACs between January 2014 and December 2016.
Results
The study included 115,362 patients with AF or VTE who were newly administered DOACs (median age, 73 years, range, 19-108 years; males, 53.0%; AF, 81.9%). A total of 7001 any bleeding (6.1%) and 2283 major bleeding (2.0%) events occurred with DOAC prescriptions. Based on multiple logistic regression analysis, the number of DDIs was significantly associated with bleeding events independent of CHADS-VASc score and Charlson Comorbidity Index (CCI). The rates of exposure to DDI drugs associated with any bleeding and major bleeding were 56.7% and 66.1%, respectively. The most common DDI drugs showed similar distributions in any or major bleeding; non-steroidal anti-inflammatory drugs (NSAIDs), antiplatelet agents, diltiazem, and amiodarone were frequently prescribed.
Conclusions
Physicians prescribing DOACs for AF or VTE should be aware of the increasing risk of bleeding associated with drugs having potential DDIs regardless of comorbidities.

Copyright © 2020 Elsevier Ltd. All rights reserved.

Thromb Res: 02 Aug 2020; 195:243-249
Lee JY, Oh IY, Lee JH, Kim SY, ... Kim YK, Bang SM
Thromb Res: 02 Aug 2020; 195:243-249 | PMID: 32823239
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Abstract

Prevalence, Incidence, and Impact on Mortality of Conduction System Disease in Transthyretin Cardiac Amyloidosis.

Donnellan E, Wazni OM, Saliba WI, Hanna M, ... Kochar A, Jaber WA

Transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized infiltrative cardiomyopathy in which conduction system disease is common. The aim of our study was to define the incidence and prevalence of high-grade atrioventricular (AV) block requiring pacemaker implantation in our quaternary referral center. This was a single-center retrospective cohort study of 369 consecutive patients with ATTR-CA who underwent 12-lead electrocardiogram at the time of ATTR-CA diagnosis. During a mean follow-up of 28 months, serial ECGs and the electronic medical record were examined for the development of high-grade AV block and pacemaker implantation. Wild-type ATTR-CA (wtATTR-CA) was diagnosed in 261 patients and 108 had hereditary ATTR-CA (hATTR-CA). A total of 35 (9.5%) had high-grade AV block requiring pacemaker implantation at the time of diagnosis of ATTR-CA. The most common conduction abnormalities evident on the baseline ECG were a wide QRS complex, present in 51% with wtATTR-CA and 48% with hATTR-CA (p = 0.62), followed by first-degree AV block, which was present in 49% with wtATTR-CA and 43% with hATTR-CA (p = 0.31). During follow-up, high-grade AV block developed in 10% of those with hATTR-CA and 12% of patients with wtATTR-CA (p = 0.64). On multivariable models, high-grade AV block was not significantly associated with increased mortality. More advanced ATTR-CA stage and a history of obstructive coronary artery disease were associated with increased mortality on multivariable models. In conclusion, the incidence and prevalence of high-grade AV block is high in patients with ATTR-CA. Patients with ATTR-CA require close monitoring during follow-up for the development of conduction system disease.

Copyright © 2020 Elsevier Inc. All rights reserved.

Am J Cardiol: 31 Jul 2020; 128:140-146
Donnellan E, Wazni OM, Saliba WI, Hanna M, ... Kochar A, Jaber WA
Am J Cardiol: 31 Jul 2020; 128:140-146 | PMID: 32650908
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Abstract

Usefulness of Neuromuscular Co-morbidity, Left Bundle Branch Block, and Atrial Fibrillation to Predict the Long-Term Prognosis of Left Ventricular Hypertrabeculation/Noncompaction.

Stöllberger C, Hasun M, Winkler-Dworak M, Finsterer J

The prognosis of patients with left ventricular hypertrabeculation/noncompaction (LVHT) is assessed controversially. LVHT is associated with other cardiac abnormalities and with neuromuscular disorders (NMD). Aim of the study was to assess cardiac and neurological findings as predictors of mortality rate in adult LVHT-patients. Included were patients with LVHT diagnosed between 1995 and 2019 in 1 echocardiographic laboratory. Patients underwent a baseline cardiologic examination and were invited for a neurological investigation. In January 2020, their survival status was assessed. End points were death or heart transplantation. LVHT was diagnosed by echocardiography in 310 patients (93 female, aged 53 ± 18 years) with a prevalence of 0.4%/year. A neurologic investigation was performed in 205 patients (67%). A specific NMD was found in 33 (16%), NMD of unknown etiology in 123 (60%) and the neurological investigation was normal in 49 (24%) patients. During follow-up of 84 ± 71 months, 59 patients received electronic devices, 105 patients died, and 6 underwent heart transplantation. The mortality was 4.7%/year, the rate of heart transplantation/death 5%/year. By multivariate analysis, the following parameters were identified to elevate the risk of mortality/heart transplantation: increased age (p = 0.005), inpatient (p = 0.001), presence of a specific NMD (p = 0.0312) or NMD of unknown etiology (p = 0.0365), atrial fibrillation (p = 0.0000), ventricular premature complexes (p = 0.0053), exertional dyspnea (p = 0.0023), left bundle branch block (p = 0.0201), and LVHT of the posterior wall (p = 0.0158). In conclusion, LVHT patients should be systematically investigated neurologically since neurological co-morbidity has a prognostic impact.

Copyright © 2020 Elsevier Inc. All rights reserved.

Am J Cardiol: 31 Jul 2020; 128:168-173
Stöllberger C, Hasun M, Winkler-Dworak M, Finsterer J
Am J Cardiol: 31 Jul 2020; 128:168-173 | PMID: 32650915
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Abstract

Randomized study defining the optimum target interlesion distance in ablation index-guided atrial fibrillation ablation.

Hoffmann P, Diaz Ramirez I, Baldenhofer G, Stangl K, Mont L, Althoff TF
Aims
While the CLOSE protocol proposes a maximally tolerable interlesion distance (ILD) of 6 mm for ablation index ablation index-guided atrial fibrillation (AF) ablation, a target ILD has never been defined. This randomized study sought to establish a target ILD for ablation index-guided AF ablation.
Methods and results
Consecutive patients scheduled for first-time pulmonary vein (PV) isolation (PVI) were randomly assigned to ablation protocols with a target ILD of 5.0-6.0 mm or 3.0-4.0 mm, with the primary endpoint of first-pass PVI. In compliance with the CLOSE protocol, the maximum tolerated ILD was 6.0 mm in both study protocols. A target ablation index of ≥550 (anterior) or ≥400 (posterior) was defined for the \'5-6 mm\' protocol and ≥500 (anterior) or ≥350 (posterior) for the \'3-4 mm\' protocol. The study was terminated early for superiority of the \'3-4 mm\' protocol. Forty-two consecutive patients were randomized and 84 ipsilateral PV pairs encircled according to the study protocol. First-pass PVI was accomplished in 35.0% of the \'5-6 mm\' group and 90.9% of the \'3-4 mm\' group (P < 0.0001). Median ILD was 5.2 mm in the \'5-6 mm\' group and 3.6 mm in the \'3-4 mm\' group (P < 0.0001). In line with the distinct ablation index targets, median ablation index was lower in the \'3-4 mm\' group (416 vs. 452, P < 0.0001). While mean procedure time was shorter in the \'3-4 mm\' group (149 ± 27 vs. 167 ± 33min, P = 0.004), fluoroscopy times did not differ significantly (4.7 ± 2.2 vs. 5.1 ± 1.8 min, P = 0.565).
Conclusion
In ablation index-guided AF ablation, an ILD of 3.0-4.0 mm should be targeted rather than 5.0-6.0 mm. Moreover, the lower target ILD may allow for less extensive ablation at each given point.

Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: [email protected]

Europace: 29 Jul 2020; epub ahead of print
Hoffmann P, Diaz Ramirez I, Baldenhofer G, Stangl K, Mont L, Althoff TF
Europace: 29 Jul 2020; epub ahead of print | PMID: 32729896
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Abstract

Reduction in Pulmonary Vein Stenosis and Collateral Damage with Pulsed Field Ablation Compared to Radiofrequency Ablation in a Canine Model.

Howard B, Haines DE, Verma A, Packer D, ... Miklavčič D, Stewart MT

- Pulmonary vein stenosis (PVS) is a highly morbid condition that can result after catheter ablation for pulmonary vein isolation (PVI). We hypothesized that pulsed field ablation (PFA) would reduce PVS risk and collateral injury compared to irrigated radiofrequency ablation (IRF).- IRF and PFA deliveries were randomized in eight dogs with two superior PVs ablated using one technology and two inferior PVs ablated using the other technology. IRF energy (25-30W) or PFA was delivered (16 pulse trains) at each PV in a proximal and in a distal site. Contrast computed tomography (CT) scans were collected at 0, 2, 4, 8, and 12-week (termination) time points to monitor PV cross-sectional area at each PV ablation site.- Maximum average change in normalized cross-sectional area at 4-weeks was -46.1 ±45.1% post-IRF compared to -5.5% ±20.5% for PFA (p Ȧ4; 0.001). PFA-treated targets showed significantly fewer vessel restrictions compared with IRF (p Ȧ4; 0.023). Necropsy showed expansive PFA lesions without stenosis in the proximal PV sites, compared to more confined and often incomplete lesions after IRF. At the distal PV sites, only IRF ablations were grossly identified based on focal fibrosis. Mild chronic parenchymal hemorrhage was noted in three left superior pulmonary vein (LSPV) lobes after IRF. Damage to vagus nerves as well as evidence of esophagus dilation occurred at sites associated with IRF. In contrast, no lung, vagal nerve or esophageal injury was observed at PFA sites.- PFA significantly reduced risk of PV stenosis compared to IRF post-procedure in a canine model. IRF also caused vagus nerve, esophageal and lung injury while PFA did not.



Circ Arrhythm Electrophysiol: 26 Jul 2020; epub ahead of print
Howard B, Haines DE, Verma A, Packer D, ... Miklavčič D, Stewart MT
Circ Arrhythm Electrophysiol: 26 Jul 2020; epub ahead of print | PMID: 32877256
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Abstract

A greater burden of atrial fibrillation is associated with worse endothelial dysfunction in hypertension.

Khan AA, Junejo RT, Alsharari R, Thomas GN, Fisher JP, Lip GYH

Atrial fibrillation (AF) and hypertension often co-exist and both are associated with endothelial dysfunction. We hypothesised that AF would further worsen endothelium-dependent flow-mediated dilatation (FMD) in hypertension patients compared to those without AF. In a cross-sectional comparison, we measured brachial artery diameter at rest and during reactive hyperaemia following 5 min of arterial occlusion in two patient groups: AF (and hypertension) (n = 61) and hypertension control groups (n = 33). The AF (and hypertension) subgroups: permanent AF (n = 30) and paroxysmal AF (n = 31) were also assessed. The permanent AF patients received heart rate and blood pressure (BP) control optimisation and were then followed up after eight weeks for repeat FMD testing. There was no significant difference in FMD between AF (and hypertension) group and hypertension control group (4.6%, 95% CI [2.6-5.9%] vs 2.6%, 95% CI [1.9-5.3%]; p = 0.25). There was a significant difference in FMD between permanent AF and paroxysmal AF groups (3.1%, 95% CI [2.3-4.8%] vs 5.9%, 95% CI [4.0-8.1%]; p = 0.02). Endothelium-dependent FMD response showed a non-significant improvement trend following eight weeks of heart rate and BP optimisation (3.1%, 95% CI [2.3-4.8%] (baseline) vs 5.2%, 95% CI [3.9-6.5%] (follow up), p = 0.09). Presence of AF generally does not incrementally worsen endothelial dysfunction in hypertension patients, although the duration and frequency of AF (paroxysmal AF to permanent AF) does lead to worsening endothelial function. Eight weeks of BP optimisation did not significantly improve endothelial dysfunction as measured by FMD.



J Hum Hypertens: 20 Jul 2020; epub ahead of print
Khan AA, Junejo RT, Alsharari R, Thomas GN, Fisher JP, Lip GYH
J Hum Hypertens: 20 Jul 2020; epub ahead of print | PMID: 32694585
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Abstract

Ion Channel and Structural Remodeling in Obesity: Mediated Atrial Fibrillation.

McCauley MD, Hong L, Sridhar A, Menon A, ... Rehman J, Darbar D

- Epidemiological studies have established obesity as an independent risk factor for atrial fibrillation (AF) but the underlying pathophysiological mechanisms remain unclear. Reduced cardiac sodium channel expression is a known causal mechanism in AF. We hypothesized that obesity decreases Nav1.5 expression via enhanced oxidative stress, thus reducing , and enhancing susceptibility to AF.- To elucidate the underlying electrophysiologic (EP) mechanisms a diet-induced obese (DIO) mouse model was used. Weight, BP, glucose, F-isoprostanes (F-IsoPs), NADPH oxidase 2 (NOX2), and protein kinase C (PKC) were measured in obese mice and compared to lean controls. Invasive EP, immunohistochemistry, Western blotting and patch clamping of membrane potentials was performed to evaluate the molecular and EP phenotype of atrial myocytes.- Pacing induced AF in 100% of DIO mice versus 25% in controls (< 0.01) with increased AF burden. Cardiac sodium channel expression,and atrial action potential duration (APD) were reduced and potassium channel expression (Kv1.5) and current () and F-IsoPs, NOX2, and PKC-α/δ expression and atrial fibrosis were significantly increased in DIO mice as compared to controls. A mitochondrial antioxidant reduced AF burden, restored , , , APD and reversed atrial fibrosis in DIO mice as compared with controls.- Inducible AF in obese mice is mediated in part by a combined effect of sodium, potassium and calcium channel remodeling and atrial fibrosis. Mitochondrial antioxidant therapy abrogated the ion channel and structural remodeling and reversed the obesity-induced AF burden. Our findings have important implications for the management of obesity-mediated AF in patients.



Circ Arrhythm Electrophysiol: 11 Jul 2020; epub ahead of print
McCauley MD, Hong L, Sridhar A, Menon A, ... Rehman J, Darbar D
Circ Arrhythm Electrophysiol: 11 Jul 2020; epub ahead of print | PMID: 32654503
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Impact:
Abstract

Prevalence and Outcome of Potential Candidates for Left Atrial Appendage Closure After Stroke With Atrial Fibrillation: WATCH-AF Registry.

Ong E, Meseguer E, Guidoux C, Lavallée PC, ... Nighoghossian N, Amarenco P
Background and purpose
As a result of contraindications (eg, frailty, cognitive impairment, comorbidities) or patient refusal, many patients with stroke and atrial fibrillation cannot be discharged on oral anticoagulant. Among them, the proportion of potential candidates for left atrial appendage closure (LAAC) and their 12-month outcome is not well known.
Methods
The prospective WATCH-AF registry (Warfarin Aspirin Ten-A Inhibitors and Cerebral Infarction and Hemorrhage and Atrial Fibrillation) enrolled consecutive patients admitted within 72 hours of an acute stroke associated with atrial fibrillation in 2 stroke centers. Scales to evaluate stroke severity, disability, functional independence, risk of fall, cognition, ischemic and hemorrhagic risk-stratification, and comorbidities were systematically collected at admission, discharge, 3, 12 months poststroke. The 2 main end points were death or dependency (modified Rankin Scale score >3) and recurrent stroke (brain infarction and brain hemorrhage).
Results
Among 400 enrolled patients (370 with brain infarction, 30 with brain hemorrhage), 31 died before discharge and 57 (14.3%) were possible European Heart Rhythm Association/European Society of Cardiology and American Heart Association/American College of Cardiology/Heart Rhythm Society candidates for LAAC. At 12 months, the rate of death or dependency was 17.9%, and the rate of stroke recurrence was 9.8% in the 274/400 (68.5%) patients discharged on a long-term oral anticoagulant strategy, as compared with 17.5% and 24.7%, respectively, in 57 patients candidate for LAAC. As compared with patients on a long-term oral anticoagulant strategy, there was a 2-fold increase in the risk of stroke recurrence in the group with an indication for LAAC (adjusted hazard ratio, 2.58 [95% CI, 1.40-4.76]; P=0.002).
Conclusions
Fourteen percent of patients with stroke associated with atrial fibrillation were potential candidates for LAAC. The 12-month stroke risk of these candidates was 3-fold the risk of anticoagulated patients.



Stroke: 08 Jul 2020:STROKEAHA120029267; epub ahead of print
Ong E, Meseguer E, Guidoux C, Lavallée PC, ... Nighoghossian N, Amarenco P
Stroke: 08 Jul 2020:STROKEAHA120029267; epub ahead of print | PMID: 32640939
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Abstract

Amplitude of QRS complex within initial 40 ms in V (VQRS): Novel electrocardiographic criterion for predicting accurate localization of outflow tract ventricular arrhythmia origin.

Xia Y, Liu Z, Liu J, Li X, ... Yu M, Fang P
Background
The initial depolarization vector of outflow tract (OT) ventricular arrhythmia (VA) varies in different origins, which may help to predict OT-VA origin more accurately.
Objective
To develop a more accurate electrocardiographic (ECG) criterion for differentiating between left and right OT-VA origins.
Methods
We studied 275 patients with successful ablation in the right ventricular OT (RVOT; n =207) or left ventricular OT (LVOT; n =68) in development cohort. The amplitude of QRS complex within initial 40 ms (QRS) in precordial leads were measured. A novel criterion for identifying the OT-VAs origin was developed based on development cohort. Predictive performance of novel criterion was further validated by comparing with previous ECG criteria (VS/VR index, V transition ratio and TZ index) in validation cohort with 107 patients (RVOT: 75, LVOT: 32).
Results
The QRS of identical precordial leads were significantly greater in LVOT group than RVOT group (P <0.05). In development cohort, QRS of V (VQRS) exhibited greatest area under the curve with 0.950, with a cut-off value of ≥0.52 mV predicting a LVOT origin (sensitivity: 86.0%, specificity: 94.6%). In validation cohort, the VQRS of ≥0.52 mV outperformed previous criteria in predictive performance (accuracy: 90.7%, sensitivity: 84.4%, specificity: 93.3%). This advantage of the VQRS over previous criteria also held true for subgroups of TZ index =0 and V R/S transition.
Conclusion
The VQRS is a novel and accurate ECG criterion to predict OT-VAs origin, which also outperforms previous criteria.

Copyright © 2020. Published by Elsevier Inc.

Heart Rhythm: 08 Jul 2020; epub ahead of print
Xia Y, Liu Z, Liu J, Li X, ... Yu M, Fang P
Heart Rhythm: 08 Jul 2020; epub ahead of print | PMID: 32653429
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Abstract

Idiopathic right ventricular arrhythmias requiring additional ablation from the left-sided outflow tract: ECG characteristics and efficacy of an anatomical approach.

Hisazaki K, Hasegawa K, Kaseno K, Miyazaki S, ... Uzui H, Tada H
Introduction
Despite the characteristic ECG findings of early activation during ventricular tachyarrhythmias (VAs) and/or excellent pacemapping in the right ventricular outflow tract (RVOT), some VAs may require additional, left-sided ablation for a cure.
Methods and results
This study included 5 patients with idiopathic VAs whose QRS morphologies were highly suggestive of an RVOT origin. The ECG characteristics and intracardiac electrocardiograms during catheter ablation were assessed. In all patients, the clinical VAs had an LBBB QRS morphology and inferior axis with a precordial R/S transition through leads V3 to V5, and negative components in lead I. The earliest activation during the VAs (local electrogram-QRS interval=-34±6.8ms) and excellent pacemapping were obtained at the posterior portion of the RVOT just beneath the pulmonary valve. However, ablation at those sites failed, and the QRS morphology of the VAs changed. During left-sided OT mapping, the earliest activation was found at sites just contralateral to the initially ablated sites of the RVOT (junction of the left and right coronary cusps=2, left coronary cusp=3). In spite of the late activation time and poor pacemapping scores, catheter ablation at those sites cured the VAs. Those successful sites were also near the transitional zone from the great cardiac vein to the anterior interventricular vein (GCV-AIV).
Conclusions
Some VAs highly suggestive of having RVOT origins require catheter ablation in the left-sided OT near the initially ablated RVOT site. Those VAs have same ECG characteristics and might have intramural origins in the supero-basal LV surrounded by the RVOT, LVOT, and GCV-AIV. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 07 Jul 2020; epub ahead of print
Hisazaki K, Hasegawa K, Kaseno K, Miyazaki S, ... Uzui H, Tada H
J Cardiovasc Electrophysiol: 07 Jul 2020; epub ahead of print | PMID: 32639637
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Abstract

Accuracy of contrast-enhanced computed tomography for thrombus detection prior to atrial fibrillation ablation and role of novel Left Atrial Appendage Enhancement Index in appendage flow assessment.

Guha A, Dunleavy MP, Hayes S, Afzal MR, ... Raman SV, Harfi TT
Aims
To evaluate diagnostic accuracy of different protocols of contrast enhanced computed tomography venogram (CTV) for LAA thrombus detection in patients undergoing AF ablation and study the correlation of the novel LAA enhancement index (LAA-EI) to LAA flow velocity obtained using transesophageal echocardiography (TEE).
Methods
Study comprised of patients undergoing CTV and TEE on the same day from October 2016 to December 2017. Three CTV scanning protocols (described in results), were evaluated wherein ECG gating was used only for those with sinus rhythm on day of CTV. LAA-EI was calculated as Hounsfield Unit (HU) in the LAA divided by the HU unit in the center of the LA. The diagnostic accuracy for CTV was calculated in comparison to TEE. The LAA-EI was compared to LAA emptying velocities as obtained from TEE.
Results
590 patients with 45.6% non-ECG-gated without delayed imaging, 26.9% non-ECG-gated with delayed imaging and 27.5% ECG-gated with delayed imaging, were included in the study. All three protocols had 100% negative predictive value with improvement in specificity from 61.8% to 98.1% upon adding delayed imaging. The LAA-EI correlated significantly with reduced LAA flow velocities (r = 0.45, p < .0001). The mean LAA emptying velocity in patients with LAA-EI of ≤ 0.6 was significantly lower than in those with LAA-EI of >0.6 (36.2 cm/s [95% CI: 32.6-39.7] vs, (58 cm/s [95% CI 55.3-60.8]), respectively (p < .0001).
Conclusion
CTV with delayed imaging (with or without ECG gating) is highly specific in ruling out LAA thrombus. The novel LAA-EI can detect low LAA flow velocities.

Copyright © 2020. Published by Elsevier B.V.

Int J Cardiol: 02 Jul 2020; epub ahead of print
Guha A, Dunleavy MP, Hayes S, Afzal MR, ... Raman SV, Harfi TT
Int J Cardiol: 02 Jul 2020; epub ahead of print | PMID: 32629004
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Abstract

Association Between Atrial Fibrillation and Sudden Cardiac Death: Pathophysiological and Epidemiological Insights.

Waldmann V, Jouven X, Narayanan K, Piot O, ... Albert CM, Marijon E

Emerging evidence suggests that atrial fibrillation (AF) may be associated with an increased risk of sudden cardiac death (SCD). However, AF shares risk factors with numerous cardiac conditions, including coronary heart disease and heart failure-the 2 most common substrates for SCD-making the AF-SCD relationship particularly challenging to address. A careful consideration of confounding factors is essential, since interventions for AF will be effective in reducing SCD only if there is a causal association between these 2 conditions. In this translational review, we detail the plausible underlying pathophysiological mechanisms through which AF may promote or lead to SCD, as well as the existing epidemiological evidence supporting an association between AF and SCD. While the role of AF in predicting SCD in the general population appears limited and not established, AF might be integrated to improve risk stratification in some specific phenotypes. Optimal AF management, including that of its associated conditions, appears to be of interest to prevent AF-related SCD, especially because the AF-SCD relationship is in part driven by heart failure.



Circ Res: 02 Jul 2020; 127:301-309
Waldmann V, Jouven X, Narayanan K, Piot O, ... Albert CM, Marijon E
Circ Res: 02 Jul 2020; 127:301-309 | PMID: 32833581
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Abstract

Association Between the European Society of Cardiology/European Society of Hypertension Heart Rate Thresholds for Cardiovascular Risk and Neuroadrenergic Markers.

Grassi G, Quarti-Trevano F, Seravalle G, Dell\'Oro R, Facchetti R, Mancia G

The recent European Society of Cardiology/European Society of Hypertension hypertension guidelines identify resting heart rate (HR) values >80 bpm as predictors of cardiovascular risk, with the unproven assumption that this might reflect the presence of a sympathetic overdrive. In the present study, we tested this hypothesis throughout the use of direct and indirect sympathetic markers. In 193 untreated moderate essential hypertensives aged 50.4±0.6 years (mean±SEM), we measured clinic and ambulatory blood pressure and corresponding HR, venous plasma norepinephrine (high performance liquid chromatography), and muscle sympathetic nerve traffic (microneurography). We then subdivided the study population into 2 groups according to HR < or >80 bpm. Eighty-four patients displayed resting HR >80 bpm, which was this cutoff value in the remaining 109 patients, the 2 groups showing superimposable age, and sex distribution. Clinic and ambulatory blood pressure were similar in the 2 groups, whereas left ventricular mass index was significantly greater in the group with HR >80 bpm. Muscle sympathetic nerve traffic values were also significantly greater in this latter group (72.77±0.9 versus vs 36.83±1.3 bursts/min, <0.0001); this being the case also for norepinephrine (293.0±8.7 versus 254.1±8.9 pg/mL, <0.002). In the whole population, there was a significant direct relationship between muscle sympathetic nerve traffic, norepinephrine, left ventricular mass index, and HR values. Similar results were obtained when 24-hour HR values were analyzed. Thus patients with hypertension displaying HR >80 bpm are characterized by a marked sympathetic overdrive, particularly when direct adrenergic markers are used. This finding suggests that cardiac and peripheral sympathetic activation are involved in the increased cardiovascular risk detected in this group of patients.



Hypertension: 28 Jun 2020:HYPERTENSIONAHA12014804; epub ahead of print
Grassi G, Quarti-Trevano F, Seravalle G, Dell'Oro R, Facchetti R, Mancia G
Hypertension: 28 Jun 2020:HYPERTENSIONAHA12014804; epub ahead of print | PMID: 32594806
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This program is still in alpha version.