bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of deep neural networks in classification of medium resolution remote sensing image
Authors: Dian-lai Wang , Ai-xia Su , Wen-ping Liu
Published: November 2020

Aiming at the problem that high misclassification rate of remote sensing image occurs due to the phenomenon of “same spectrum different matter” and “same object different spectrum”, the deep neural networks(DNN) is proposed to the classification of medium resolution remote sensing image. The deep neural networkstake advantage of the neural network with multiple hidden layers to learn the characteristics that can describe the essential attributes of data, and has achieved high accuracy in land cover classification in Miyun District, Beijing city. The experimental results indicate that the classification accuracy of this algorithm is the highest compared with SVM and BP neural network, the classification accuracy reaches 96.53%, and the classification accuracy is 10.39% higher than that of SVM. The kappa coefficient of DNN is 0.95, which is also the highest among the comparison algorithm. So, the DNN can apply to the classification of moderate resolution remote sensing image.
Comparison of Convolutional Sparse Coding Network and Convolutional Neural Network for Pavement Crack Classification: A Validation Study
Authors: Tang Haitong , Shi Jun , Lu Xia , Yin Zhichao , Huang Lixue , Jia Dongbao , Wang Nizhuan
Published: November 2020

Accurate and effective identification of pavement cracks can provide a reference for pavement performance evaluation and prediction. Inspired by recent outstanding performance of convolutional sparse coding theory in various research fields, we envision whether convolutional sparse coding can be beneficial for crack detection in complex environments. Therefore, based on the multi-layer convolutional sparse coding (ML-CSC) model, this paper combines multi-layer iterative soft threshold algorithm (ML-ISTA) and convolutional neural network (CNN) into recurrent neural networks (RNN) to identify crack images across the simulated experiments. And in different noise environments, different training cycles and different epochs, the ML-ISTA is compared with traditional CNN and the layered basis pursuit (LBP), which is another popular algorithm for ML-CSC. Experimental results showed that under the different training conditions with the same parameter setting, the stability and accuracy of the ML-ISTA is better than CNN and LBP. The ML-ISTA can achieve crack identification accuracy of 99.36% efficiently, which demonstrates the effectiveness of convolutional sparse coding in crack detection.
Helmet Detection Algorithm Based on Single Pixel Zoom
Authors: Zhou Yongheng , Jiang Lifen , Liang Yan , Ma Chunmei , Sun Huazhi , Nie ShuaiBao , Zuo Ying
Published: November 2020

The automatic detection technology of helmet wearing is of great significance to the safety monitoring of construction site. It is difficult to detect a helmet when the object is small, overlapped, or unclear. Therefore, we propose SPZ-Det model to improve the performance of detect small targets in helmet detection task. We redesign the backbone network layers and proposes a Single Pixel Zoom (SPZ) module. SPZ-Det introduces the lower-level feature map, while for the same scale feature map, we select the higher-level feature map. Then the important elements of each feature map layer are amplified by SPZ module to solve the problem of small object feature fading. In the attention module of SPZ, the residual mechanism is introduced to weaken the influence of the attention. The proposed model improves the detection accuracy and keeps the detection speed. On the Safety-Helmet-Wearing dataset, the mAP of SPZ-Det is 27.9% higher than Efficientdet-d0 and gets an 8.8% increase compares with YOLOv3.
DisCANTree: A Distributed Algorithm for Incremental Frequent Itemset Mining based on MapReduce
Authors: Xiao Wen , Hu Juan
Published: November 2020

Frequent itemset mining is one of the most important data mining tasks. Classical frequent itemset mining algorithms need to store data in a centralized way and run in a batch way, which cannot meet the requirements of fast updating big data mining. In this paper, we propose a distributed incremental frequent itemset mining algorithm, DisCANTree, which uses CANTree to store the conditional database, achieves the load balance between nodes by grouping all items, updates the new transaction to the existing CANTree to avoid the load of tree reconstruction, and uses the efficient FPGrowth algorithm to mine CANTree to generate frequent itemsets. The popular distributed programming model MapReduce and its open source system Hadoop are used to implement the DisCANTree algorithm. The experimental results show that the DisCANTree algorithm has more advantages than the most popular PFP algorithm in performance as well as the number of transferred records between nodes, and especially suits for the fast updating sparse big data.
Intelligent Test Paper Generation Based on Dynamic Programming Algorithm
Authors: Wang YiFei , Wang SuRong
Published: November 2020

This paper describes the problem of intelligent paper grouping and its mathematical model. By optimizing and improving the traditional dynamic programming algorithm, its space complexity is reduced from O(nb) to O(b). At the same time, the flexibility of dynamic programming algorithm is increased by using marker function and tracking algorithm, and the result composition is tracked to obtain the optimal solution. Finally, through several experiments, the improved dynamic programming algorithm is compared with the greedy algorithm and brute force algorithm, and it is found that the improved dynamic programming algorithm has a very good result and is with high efficiency when applied to the simple test paper. It is the most recommended algorithm among the two algorithms compared in this paper.
A Knowledge Graph Based Framework in Relationship Modelling and Real-time Monitoring of Market Participants
Authors: Cheng Wenliang , Guo Kaihao , Jiang Tianpei , Zhang Haipeng
Published: November 2020

Various types of relationships among participants exist in the foreign exchange market, such as transaction, credit relations inside the market and subcompany, investing and shareholding relations outside the market. In the market with complex relationships, an incident happened in one institution may have “butterfly effect”. To monitor systemic financial risks, we integrate various types of data and establish a Knowledge Graph describing the relationships between market participants. Based on the Knowledge Graph, we design a framework to measure the impact of various events on the entire market by connecting the internal market relationships to external market related incidents. By using the BiLSTM-CRF model, we extract the relevant entities in the market news with high accuracy and measure the impact on the market with graph related indicators such as closeness and betweenness centralities. In addition, to use external unstructured data, we use a document-level event extraction method to analyse these unstructured datasets and extract new events and relationships from them to dynamically update the Knowledge Graph.
Construction of a campus Q&A platform based on big data and microservice architecture
Authors: Du Zhixiong , Li Jun , Xiao Zihan , Yu Chenhao , Tang lu , Chen Guangxue , Luo Wanyu
Published: November 2020

As an indispensable part of the network education system, the network answering system has become a research hotspot in the computer field. Based on the current campus platform construction, this paper proposes a campus Q&A platform based on big data and microservice architecture. The microservice framework uses Springcloud and its related components, and the big data component is a combination of components using ElasticSearch and Kafka and Storm. The platform has been put into operation for the construction of the majority of college students and has good practicability.
A Competency Mining Method Based on Latent Dirichlet Allocation (LDA) Model
Authors: Wu Jiying , Son Guandong , Wang Sihui
Published: November 2020

A text mining approach based on latent Dirichlet allocation (LDA) is proposed to analyze the competency characteristics. First, we briefly introduce the principle and hypothesis of latent Dirichlet allocation (LDA) model. Second, we elaborate the idea of using LDA topic model to extract competency, Then, we use Chinese text materials such as biographies and interviews of Chinese scientific and technological talents as data sources to conduct experiments, and obtain four competency topics including knowledge, attitude, quality and values. The research results preliminarily verify the effectiveness of latent Dirichlet allocation (LDA) model in competency research, but there are still many details to be improved in the future.
Multi-convLSTM neural network for sensor-based human activity recognition
Authors: Li Zili , Liu Yixin , Guo Xuerong , Zhang Ji
Published: November 2020

In recent years, human activity recognition (HAR) has attracted a lot of attention due to its wide application, such as indoor positioning and navigation. This paper proposes a MconvLSTM to construct a multi-unit deep network structure,which can effectively improve the accuracy of HAR. Firstly, the input data is dimensionally expanded. Secondly, multiple convLSTM module are used to input data from different sensors to achieve partial weight sharing. Multiple outputs are merged finally. The experimental results show that the partial weight sharing mechanism and dimension expansion effectively improve the extraction of single sensor features, aiming to improve the activity recognition rate. Using public UCI datasets for testing, the accuracy is significantly improved compared to traditional convLSTM network results.
Identification of Anoectochilusroxburghibased on transfer learning
Authors: Liu Yansong , Chai Qinqin , Wang Wu , Zhang Xun
Published: November 2020

Different varieties of Anoectochilusroxburghi(A. roxburghi) have different medicinal values. However, the identification and the clinical efficacy of A. roxburghi was seriously affe cted by the phenomena of doping and adulteration. Thus, accurate identification of different va rieties of A.roxburghiis important. However, traditional identification methods for A.roxburghii dentification are usually time-consuming, laborious or have low accuracy. Thus, an A.roxburgh i leaf image recognition method based on transfer learning is proposed. The model use convolu tion neural network to extract leaf features of A.roxburghautomatically. Then, the knowledge, l earned by a model from a large-scale image data set ImageNet, is transferred to realize the task of A.roxburghi image recognition with the help of transfer learning.Low training cost and high precision classification of leaf strains is realized in this way. Finally, 368 leaf images of 6 speci es of A.roxburghi are collected for recognition, including dayuanye, xiaoyuanye,and etc.. To te st the transfer effect, the Resnet50 transfer learning model is compared with the the other four models. The comparison results show that the accuracy of Resnet50 transfer learning model rea ches 100% in a quicker speed, which illustrates that the model has good robustness and better p erformance of realizing the accurate recognition and classification of the leaves of A.roxburghi. Moreover, data augmentation helps to reduce the over-fit phenomenon of the transfer learning model.
Effect of continuous annealing process on microstructure, texture and properties of cold rolled dual phase steel
Authors: Wei-wei Wang , Li Guang-ying , Liu Liu
Published: November 2020

In order to improve the strength and plasticity of cold rolled dual phase steel DP980, the relationship between annealing process and properties were systematically studied by adjusting continuous annealing process parameters with 800-840?. The primary ferrite, the secondary ferrite, recrystallized ferrite grains, island martensite distribution,precipitate and texture of different phases at different annealing temperatures were analyzed by methods with OM, SEM, TEM and EBSD. The effect of continuous annealing temperature on the strength and plasticity of dual phase steel DP980 were researched by mechanical tensile test in addition. The results show that recrystallized ferrite grains and the secondary ferrite can be refined by optimizing and adjusting the continuous annealing process, at same time, a small amount of retained austenite is distributed beside the island martensite on the microstructure of DP980. The precipitates NbC particle size is about 50∼150 nm. Finally, the fine uniform microstructure, the dispersed martensite and fine precipitates are beneficial to the improvement of the strength and plasticity which increase the strength plasticity balance to a level of 15 -18GPa%.
Increasing body size and fecundity in a salamander over four decades, possibly due to global warming
Authors: Okamiya Hisanori , Hayase Nagatoshi , Kusano Tamotsu
Published: November 2020

Recent climate change has been shown to affect phenotypic traits, such as body size and fecundity, in some animals. It is important to assess the response of a species to climate change for predicting a population’s future. We compared historic and contemporary body size and clutch size measurements in the lentic breeding salamander, Hynobius tokyoensis, collected from a wide range of latitudes in its geographical range and concluded that the species has gone through significant increases in body size and clutch size over the last four decades. Although a decrease in body size due to climate change is well documented for other species, reports of an increase in body size are rare. In addition, we found that increases in temperature and precipitation were constant regardless of latitude, but that the ratios of increase in body size and clutch size were greater in high-latitude populations. Our results suggest that, even within a species, the magnitude of the response to climate change depends on the geography of the population.
IgA vasculitis (Henoch–Schönlein purpura): refractory and relapsing disease course in the adult population
Authors: Van de Perre Els , Jones Rachel B , Jayne David R W
Published: November 2020

Background

The disease course of adult immunoglobulin A (IgA) vasculitis (IgAV; Henoch–Schönlein purpura) has not been well defined.

Methods

In a retrospective survey, we studied 85 adult IgAV patients with extended follow-up (median 43 months) for 67 patients.

Results

Only 33 of 67 (49%) achieved complete remission. Ongoing renal disease was the most common persistent organ manifestation, but extra-renal disease activity was also present in >50% of patients not achieving complete remission. Twenty-nine of 67 (43%) had relapsing disease, with 18/67 (27%) experiencing several relapses. Skin disease was the most common feature in relapsing patients, followed by nephritis. At 4 years of follow-up, 6 of 29 (21%) experienced progressive disease and 10/29 (34%) relapsing disease. Five of 67 (7%) developed nephritis after diagnosis, within the first 6 months of follow-up. At final follow-up, 10 of 67 (15%) had chronic kidney disease Stage ≥G3a, 18 (27%) haematuria and 13 (19%) proteinuria. No therapy appeared particularly effective and only 6/17 patients treated with mycophenolate mofetil experienced a good response.

Conclusions

The disease course of adult IgAV is different from that seen in children, with higher frequency of persisting and relapsing disease. Renal disease is the main determinant of ongoing disease activity, but extra-renal features were seen in >50% of patients with chronic disease activity. No clear conclusions on use or choice of immunosuppressive agent could be made based on our experience.
The additive prognostic value of B-lines and heart rate reserve during “kindergarten” stress echocardiography
Authors: Scali M.A , Ciampi Q , Zagatina A , Prota C , Cortigiani L , Borguezan-Daros C , Wierzbowska-Drabik K , Djordjevic-Dikic A , Simova I , Boshchenko A , Gaibazzi N , Torres M.A , Carpeggiani C , Picano E
Published: November 2020

Background

B-lines by lung ultrasound (LUS) were added to stress echo (SE) as a direct sign of pulmonary congestion useful to establish an objective link between dyspnoea symptoms and acute heart failure. They are feasible with “kindergarten” training of few hours and pocket size instruments.

Aim

To assess the prognostic value of “kindergarten SE” only based on B-lines and imaging-independent heart rate reserve (HRR).

Methods

We enrolled 2,149 patients (age 63±16 yrs, 831 women, 39%) with known or suspected coronary artery diseasereferred for exercise (n=1,015), dipyridamole (n=1,039), adenosine (n=16) or dobutamine (n=79) SE. By LUS, we adopted the 4-site simplified scan, each site scored from 0=normal A-lines, to 10=coalescing B-lines. HRR was assessed as peak/rest ratio of heart rate. All patients were followed-up.

Results

Interpretable HRR and LUS data were obtained in all patients (feasibility=100%). Abnormal B-lines (≥2) at peak stress were present in 756 patients (35%). Abnormal HRR (≤1.80 for exercise and dobutamine and ≤1.22 for vasodilator) was found in 986 patients (46%), both positivity in 388 patients (18%). During a median follow-up time of 15 months, 137 spontaneous events occurred in 120 patients: 38 deaths, 28 myocardial infarctions, 60 acute heart failures, 11 strokes. B-lines ≥2 and/or reduced HRR were independently associated with adverse outcome (see figure). At multivariable analysis, a three-fold increased risk of death was observed when both B-lines and HRR were abnormal (Hazard ratio: 3.097, 95% Confidence Intervals 1.095–8.754, p=0.03).

Conclusions

A super-simplified stress test (“SE without SE”) with simple heart rate assessment by EKG and LUS for B-lines evaluates key variables such as chronotropic incompetence (due to reduced sympathetic reserve) and pulmonary congestion (due to backward acute heart failure) and allows an accurate prediction of outcome.

Figure 1

Funding Acknowledgement

Type of funding source: None
Stratifying the prognostic capability of cardiovascular magnetic resonance in severe aortic stenosis: a machine learning approach
Authors: Kwak S , Everett R , Ko T , Lee H , Lee W , Treibel T , Chin C , Captur G , Schulz-Menger J , Newby D , Greenwood J , Moon J , Dweck M.R , Lee S.P
Published: November 2020

Background

Cardiovascular magnetic resonance (CMR) demonstrates promise in improving patient risk stratification in aortic stenosis (AS). We explored whether machine learning might provide further insights into the prognostic capability of CMR parameters.

Methods

Severe AS patients (n=440) undergoing AVR were prospectively enrolled across 10 international sites, and CMR performed prior to AVR. A machine learning prediction model using a random survival forest (RSF) was trained with 29 variables, including 13 CMR, 4 echocardiography, and 12 clinical parameters, using post-AVR mortality as an outcome. The impact of the important variables on the outcome (partial dependency) was examined.

Results

The most predictive CMR parameters in the RSF model were the extracellular volume fraction (ECV%), followed by right ventricular ejection fraction (RVEF), late gadolinium enhancement (LGE%), and indexed left ventricular end-diastolic volume (LVEDVi). Regarding the partial effects, the predicted mortality increased strongly once the ECV% exceeded 26.5% (Figure 1A). The LGE% was associated with an increased risk of mortality, which reached a plateau beyond the level of 2% (Figure 1C). There were U-shaped relationships between mortality and both RVEF and LVEDVi, with the lowest mortality seen at RVEF 70% and LVEDVi 68ml/m2 (Figure 1B, D). These trends of predicted outcomes by each variable were verified in the Kaplan-Meier curves and Cox analyses (Table). In both Cox and RSF models, the predictability was substantially increased when these four CMR parameters were added to conventional clinical risk factors. An AS-CMR risk score comprised of these four parameters presented a stepwise increase in mortality with increasing adverse CMR features (p<0.001).

Conclusions

Our machine learning analysis using RSF has identified ECV%, RVEF, LGE%, and LVEDVi as key prognostic markers in severe AS with a nonlinear influence of each parameter on mortality post-AVR.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study was supported by grants from the Korean Health Technology R & D Project, Ministry of Health, Welfare & Family Affairs, Republic of Korea (HI16C0225 and HI15C0399) and the National Institute for Health Research (NIHR) infrastructure at Leeds.
Prevalence and prognostic value of left ventricular late gadolinium enhancement in patients with idiopathic outflow tract ventricular arrhythmias
Authors: Nucifora G , Muser D , Castro S , Casado Arroyo R , Benhayon D , Liuba I , Sadek M , Magnani S , Callans D , Frankel D , Marchlinski F , Santangeli P
Published: November 2020

Background

Patients with idiopathic outflow tract ventricular arrhythmias (OTVAs) and structurally normal heart by ECG and echocardiogram often undergo cardiac magnetic resonance (CMR) study to evaluate for presence of concealed myocardial abnormalities with late gadolinium enhancement (LGE). However, the clinical impact of incidental LGE finding in the left ventricle (LV) in patients with idiopathic OT-VAs is unclear. Accordingly, the aim of the present study was to investigate the prevalence, characteristics and prognostic significance of isolated LV LGE in a large population of patients with OTVA undergoing CMR.

Methods

A total of 364 consecutive patients (43±16 years, 53% male) with OTVA and negative routine diagnostic work-up were included. All patients underwent a CMR study with LGE imaging for detection of scar/replacement fibrosis. Presence of LGE was correlated with long term major adverse cardiovascular events including sudden cardiac death (SCD), resuscitated cardiac arrest and nonfatal documented sustained ventricular tachycardia.

Results

Isolated LGE in the LV was identified in 15 patients (4%), typically involving the inferolateral wall (11 cases, 73%) and having a median extension of 3 (2–5)% of the LV mass. All cases showed a midmyocardial/subepicardial distribution consistent with a possible prior myocarditis. Patients with incidental finding of LV-LGE were older (55±13 years vs. 42±16 years; p<0.01) and were more frequently males (80% vs. 51%; p=0.03). After a median follow-up of 69 (47–98) months, none of the patients in the LV-LGE group and 1 patient (0.3%) in the non-LGE group (p=1.0) experienced the composite end-point which consisted in an episode of sustained VT with hypotension and dizziness. The patient subsequently underwent effective radiofrequency ablation of the VT from the right ventricular outflow tract.

Conclusion

In this large CMR study, isolated LV scar was found in 4% of patients with idiopathic OT-VAs, was small in size with distribution consistent with prior myocarditis. The LGE abnormality did not portend a negative prognosis.

Funding Acknowledgement

Type of funding source: None
Extracellular volume fraction by T1 mapping predicts omprovement of left ventricular ejection fraction after catheter ablation in patients with non-ischemic cardiomyopathy and atrial fibrillation
Authors: Azuma M , Kato S , Kodama S , Hayakawa K , Kagimoto M , Iguchi K , Fukuoka M , Fukui K , Iwasawa T , Utsunomiya D , Kimura K , Tamura K
Published: November 2020

Background

The Catheter Ablation versus Standard Conventional Therapy in Patients with Left Ventricular Dysfunction and Atrial Fibrillation (CASTLE-AF) trial has shown that the catheter ablation (CA) for atrial fibrillation (AF) significantly reduced the risk of death and hospitalization for heart failure in patients with non-ischemic dilated cardiomyopathy (NIDCM) and AF (N Engl J Med 2018; 378:417–27). In addition, the Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction (CAMERA-MRI) study demonstrated that the absence of myocardial fibrosis on late gadolinium enhanced (LGE) magnetic resonance imaging (MRI) is associated with improvement of left ventricular systolic function after CA in NIDCM patients with AF (J Am Coll Cardiol 2017; 70:1949–61). Extracellular volume fraction (ECV) by T1 mapping has emerges as a non-invasive mean to quantify diffuse myocardial fibrosis.

Purpose

The aim of this study was to compare the predictive value of LGE-MRI and ECV by T1 mapping for the prediction of improvement of LVEF after CA in NIDCM patients.

Methods

A total of twenty-eight patients with NIDCM and AF (age: 67±10 years; 25 (89%) male; LVEF: 34.1±8.8%) were studied. Using a 1.5T MR scanner and 32 channel cardiac coils, cine MRI, LGE-MRI, pre- and post- T1 mapping images of LV wall at mid-ventricular level (modified Look-Locker inversion recovery sequence) were acquired. Myocardial fibrosis on LGE was defined as area with >5SD signal intensity of normal myocardium. ECV from six segments of mid ventricular level were averaged for each patient. All patients underwent CA for AF, and the improvement of LVEF before and after CA were evaluated by echocardiography.

Results

All patients restored sinus rhythm after CA at the time of echocardiography. The mean LVEF was 34.1±8.8% before CA and 49.1±12.0% after CA (p<0.001), resulting an improvement of 15.0±11.8%. Significant correlation was found between improvements in LVEF and amount of fibrosis on LGE-MRI (r=−0.40, p=0.034), improvement of LVEF and ECV (r=−0.55, p=0.008). In the ROC analysis, ECV had a higher discriminative ability for the improvement of LVEF after CA compared with amount of fibrosis on LGE-MRI (AUC 0.885 vs 0.650) (Figure).

Conclusions

In NIDCM patients with AF, ECV by T1 mapping had better predictive ability for improvement of LVEF after CA in comparison to LGE-MRI.

ROC curves of ECV and LGE-MRI

Funding Acknowledgement

Type of funding source: None
Use, indications and diagnostic yield of implantable loop recorder in clinical practice: a single, high volume, tertiary care centre experience
Authors: Castagno D , Donadoni M , Golzio P.G , Budano C , Anselmino M , Ferraris F , Jorfida M , Bissolino A , Magnano M , Gagliardi M , Di Summa R , Ruffini S , Gaita F , Giustetto C , De Ferrari G.M
Published: November 2020

Introduction

Besides the established class I indication for the evaluation of patients with recurrent syncope of uncertain origin, implantable loop recorders (ILRs) have been increasingly used for other diagnostic purposes (e.g. detection of atrial fibrillation (AF) following cryptogenic stroke).

Purpose

To describe the main indications to ILR and to investigate procedural parameters, outcomes and diagnostic yield of ILR in a single, high-volume tertiary care centre.

Methods

All patients undergoing ILR implantation between October 2010 and October 2019 were consecutively enrolled in this study. Clinical characteristics of patients, procedural data and outcomes were collected. The indications to ILR implantation were divided into four categories: 1) AF detection in patients with recent cryptogenic stroke or peripheral thromboembolism [CRYSP], 2) recurrent syncope of uncertain origin [RSUO], 3) monitoring of ventricular arrhythmic events [VAE] in patients with predisposing cardiomyopathy/channelopathy, 4) monitoring of AF burden [AFB]. The main endpoint of the study was the diagnostic yield (number of definitive diagnoses made) and the time to diagnosis following ILR implantation. The occurrence of acute or subacute complications was used as a secondary safety endpoint.

Results

Overall, 1008 patients underwent ILR implantation (mean age 64 years, 43% female). The two main indications to ILR were AF detection following CRYSP and RSUO (41% and 34% of all implantations respectively, table 1). The commonest site of implantation was the left parasternal position (570 patients, 57%), median procedural time was 20 minutes (IQR 15–25). During a median follow-up of 580 days (186–1179), a definitive diagnosis was achieved in 366 (36%) patients after a median time of 208 days (IQR 59–515) [table 1 shows details and action taken following diagnosis for each indication subgroup]. Infections requiring ILR extraction or pocket revision occurred in 12 patients (1.2%).

Conclusions

In this cohort of patients use of ILR was associated with a good diagnostic yield regardless of the initial indication, triggered timely therapeutic actions and was overall safe.

Funding Acknowledgement

Type of funding source: None
Prediction of atrial fibrillation by 12-lead electrocardiogram parameters in patients without structural heart disease
Authors: Hirota N , Suzuki S , Arita T , Yagi N , Otsuka T , Semba H , Kano H , Matsuno S , Kato Y , Uejima T , Oikawa Y , Yajima J , Yamashita T
Published: November 2020

Background

Recently, the analysis of electrocardiogram (ECG) waveform by artificial intelligence has been reported to pick out those who have atrial fibrillation (AF) or have a high potential of developing AF, which, however, cannot explain the mechanisms or algorisms for the prediction from its nature.

Purpose

The purpose of this study is to conduct a comprehensive analysis to investigate the difference of weighting in predicting capability for AF among hundreds of automatically-measured ECG parameters using a single ECG at sinus rhythm.

Methods and results

Out of Shinken Database 2010–2017 (n=19170), 12825 patients were extracted, where those with ECG showing AF rhythm at the initial visit (including all persistent/permanent AF and a part of paroxysmal AF) and those with structural heart diseases were excluded. Out of 639 automatically-measured ECG parameters in MUSE data management system (GE Healthcare, USA), 438 were used. [Analysis 1] A predicting model for paroxysmal AF were determined by logistic regression analysis (Total, n=12825; paroxysmal AF, n=1138), showing a high predictive capability (AUC = 0.780, p<0.001). In this model, the relative contribution of ECG parameters (by coefficient of determination) according to the time phase were P:72.4%, QRS:32.7%, and ST-T:13.7%, respectively (Figure A). [Analysis 2] Excluding AF at baseline, a predicting model for new-developed AF were determined by Cox regression analysis (Total, n=11687; new-developed AF, n=87), showing a high predictive capability (AUC = 0.887, p<0.001). In this model, the relative contribution of parameters (by log likelihood) according to the time phase were P:40.8%, QRS:42.5%, and ST-T:24.9%, respectively (Figure B).

Conclusions

We determined ECG parameters that potentially contribute to picking up existing AF or predicting future development of AF, where the measurement of P wave strongly contributed in the former whereas all time phases were similarly important in the latter.

Weighting of parameters to predict AF

Funding Acknowledgement

Type of funding source: Private hospital(s). Main funding source(s): Self funding of the institute
Multicenter study of novel mapping technique to detect non-pulmonary vein triggers excluding the origin from left atrial posterior wall and superior vena cava
Authors: Matsunaga Y , Egami Y , Yano M , Yamato M , Shutta R , Nishino M , Tanouchi J
Published: November 2020

Background

It has been reported that elimination of non-pulmonary vein (PV) triggers after PV isolation is a good predictor of atrial tachyarrhythmia free survival. However, precise mapping of triggers outside from superior vena cava (SVC) or left atrial posterior wall (LAPW) are difficult. The aim of this study is to assess the efficacy of self-reference mapping technique to eliminate non-PV triggers originated from outside of primordial pulmonary vein area.

Methods

Total of 431 patients (446 procedures) underwent atrial fibrillation (AF) ablation in a hospital and in a medical center from January 2017 to March 2019. After isolation of PV, non-PV triggers were induced with isoproterenol and/or adenosine triphosphate. Reproducible non-PV triggers were targeted to ablate using following self-reference mapping technique: A trigger conducts centrifugally and the earliest site should be distinguished from other later activated sites. Using a PentaRay multipolar catheter, the operators annotated the earliest site of local activation and a reference tag was placed. The multipolar catheter was then moved to the reference tag and the process repeated. Ultimately, we identified clusters of early circumferential activation and ablated.

Results

A total of 32 non-PV triggers excluding the origin from LAPW and SVC were induced in 23 patients. Nineteen triggers (59%) were located in the right atrium and 13 triggers (41%) in the left atrium (Figure 1). All triggers were eliminated with ablation and AF was non-inducible in all patients at the end of the procedure. During the follow-up (529±270 days), 18 patients (77%) were free from atrial tachyarrhythmias after a 3-month blanking period. Three patients received additional ablation procedures for recurrent atrial arrhythmias. No non-PV triggers ablated during the previous procedure were observed.

Conclusion

A novel self-reference mapping technique is useful for eliminating non-PV triggers in terms of the short- and long-term success.

Figure 1. Distribution of non-PV triggers

Funding Acknowledgement

Type of funding source: None
Circumferential pulmonary vein ablation with or without a linear lesion at the left atrial roof for catheter ablation of persistent atrial fibrillation (9-year follow-up)
Authors: Kettering K
Published: November 2020

Background

Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. Circumferential pulmonary vein ablation is still the standard approach in these patients. However, the results are not very favourable and more complex ablation strategies are the subject of current controversy. Therefore, we have evaluated the effect of an additional linear lesion at the roof of the left atrium on the long-term outcome.

Methods

A total of 240 patients (125 men, 115 women; mean age 70 years (SD ± 15 years)) with symptomatic persistent atrial fibrillation underwent a circumferential pulmonary vein ablation procedure in combination with an additional linear lesion at the roof of the left atrium (group A). After discharge, patients were scheduled for repeated visits at the arrhythmia clinic at 1, 3, 6, 12, 24, 36, 48, 60, 72, 84, 96, 102 and 108 months after the ablation procedure. The long-term follow-up data was compared to 240 patients who underwent circumferential pulmonary vein ablation without an additional linear lesion at the roof of the left atrium (group B).

Results

The ablation procedure could be performed as planned in all patients. Fifty-five out of 240 patients (22.9%) in group A and 58 out of 240 patients (24.2%) in group B experienced an arrhythmia recurrence within the first 3 months after ablation requiring an electrical cardioversion. At 108-month follow-up, analysis of a 168-hour ECG recording revealed no evidence for an arrhythmia recurrence in 135/240 patients (56.3%) in group A and in 111/220 patients (46.3%) in group B. In 73/240 patients (30.4%) in group A and 66/240 patients (27.5%) in group B, only short episodes of paroxysmal atrial fibrillation were documented. In 32 patients (13.3%) in group A, a recurrence of persistent atrial fibrillation (>48 hours) was revealed by the long-term recordings (group B: 63 patients (26.2%)). The lower arrhythmia recurrence rate in group A was partially due to a lower incidence of atypical atrial flutter after catheter ablation. The rate of repeat ablation procedures was significantly lower in group A than in group B. There were no major complications.

Conclusions

Catheter ablation of persistent atrial fibrillation comprising a circumferential pulmonary vein ablation and an additional linear lesion at the roof of the left atrium provides more favourable results than circumferential pulmonary vein ablation alone. The effect is more pronounced during long-term than during short-term follow-up.

Funding Acknowledgement

Type of funding source: None
Uninterrupted direct oral anticoagulants and vitamin K antagonists during ablation for atrial fibrillation: an updated meta-analysis
Authors: Brockmeyer M , Lin Y , Parco C , Karathanos A , Krieger T , Schulze V , Heinen Y , Bejinariu A , Mueller P , Makimoto H , Kelm M , Wolff G
Published: November 2020

Background

Uninterrupted anticoagulation during catheter ablation of atrial fibrillation (CAAF) became standard of care after positive results of trials investigating vitamin K antagonists (VKA). Previous studies and meta-analyses of uninterrupted direct oral anticoagulants (DOAC) vs. VKA have given controversial results. We thus aimed to elucidate the risks and benefits of uninterrupted DOAC vs. VKA during CAAF in an updated meta-analysis of randomized controlled trials (RCTs).

Methods

Online databases were searched for RCTs comparing uninterrupted DOAC to VKA in patients undergoing CAAF until September 2019. Data from retrieved studies were analysed in a comprehensive meta-analysis. Primary safety outcome was major bleeding; primary efficacy outcome was stroke or transient ischemic attack (TIA). Secondary outcomes included a composite of major bleeding and stroke or TIA, minor bleeding, acute cerebral lesions on magnetic resonance imaging (ACL) and mortality.

Results

Six eligible RCTs comprising 2,369 patients were included. Pooled meta-analysis showed no significant differences in DOAC vs. VKA concerning the rates of major bleeding (2.2% vs. 3.8%; odds ratio (OR) 0.69, 95% confidence interval (CI) 0.30–1.56; p=0.37) and stroke or TIA (0.2% vs. 0.2%; OR 0.97, CI 0.20–4.72; p=0.97). There were no significant differences found in secondary outcomes (OR 0.73, p=0.49 for composite of major bleeding and stroke or TIA; OR 1.08, p=0.52 for minor bleeding; OR 1.12, p=0.59 for ACL; and OR=0.60, p=0.64 for all-cause mortality).

Conclusion

Our meta-analysis suggests that uninterrupted periprocedural anticoagulation with DOAC or VKA is characterized by a similar risk/benefit ratio in patients undergoing CAAF with comparable rates of major bleeding and stroke.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Medical faculty of the Heinrich-Heine-University Düsseldorf, Germany
Recurrence of atrial fibrillation after catheter ablation is associated with major adverse cardiac and cerebrovascular events: insights from AF frontier ablation registry
Authors: Usuda K , Kato T , Tada H , Tsuda T , Takeuchi K , Niwa S , Usui S , Sakata K , Hayashi K , Furusho H , Kawashiri M , Takamura M , Nagashima K , Okumura Y
Published: November 2020

Background

Recent observational studies have suggested that catheter ablation for atrial fibrillation (AF) is significantly associated with reduced risk for stroke, cardiovascular events and all-cause death. However, little is known whether late recurrence of AF after catheter ablation is associated with worse clinical outcomes.

Purpose

We aimed to clarify whether late recurrence of AF after catheter ablation is associated with major adverse cardiac and cerebrovascular events (MACCE).

Methods

We retrospectively investigated 2,737 participants (74.4% men, mean age 63.4±10.3 years, 62.7% paroxysmal AF) who received first catheter ablation for AF and completed follow-up more than 3 months after the procedure from AF Frontier Ablation Registry, a multicenter cohort study in Japan. We evaluated an association between late recurrence of AF after catheter ablation and first MACCE in cox-regression hazard models adjusted for known risk factors. MACCE were defined as stroke/transient ischemic attack (TIA), cardiovascular events or all-cause death. Late recurrence was defined as AF relapse more than 3 months after the procedure.

Results

During a mean follow-up period of 25.2 months, 2,070 patients (75.6%) were free from AF after catheter ablation and 122 patients (4.5%) had MACCE (ischemic stroke 18 [14.8%], hemorrhagic stroke 16 [13.1%], TIA 7 [5.7%], hospitalization for heart failure 19 [15.6%], acute coronary syndrome 19 [15.6%], hospitalization for other cardiovascular events 24 [20%] and all-cause death 19 [15.6%]). The MACCE occurred significantly more frequently in the recurrence group than in non-recurrence group (7.5% vs. 3.5%; hazard ratio [HR] 1.85; 95% confidence interval [CI] 1.28–2.65; P=0.001) (Figure). Multivariate analysis revealed that baseline age (HR 1.05; 95% CI 1.03–1.08; P<0.001), heart failure (HR 1.76; 95% CI 1.17–2.66; P=0.007), old myocardial infarction (HR 4.49; 95% CI 2.59–7.81; P<0.001), non-ischemic cardiomyopathy (HR 2.56; 95% CI 1.47–4.46; P=0.001), left atrial diameter (HR 1.22 per 5-mm increase; 95% CI, 1.06–1.41; P=0.006) and recurrence of AF (HR 1.69; 95% CI 1.17–2.44; P=0.005) were independently associated with the incidence of MACCE after catheter ablation.

Conclusion

In the Japanese multicenter cohort of AF ablation, late recurrence of AF was independently associated with increased MACCE, suggesting the significance of sinus rhythm maintenance by catheter ablation.

Kaplan-Meier curves for MACCE

Funding Acknowledgement

Type of funding source: None
Comparable risk of ischemic stroke in patients with screen-detected atrial fibrillation on single timepoint handheld ECG screening to patients with known AF
Authors: Sun W , Freedman B , Martinez C , Wallenhorst C , Yan B.P.Y
Published: November 2020

Aims

To determine risk of ischemic stroke in patients with single timepoint screen-detected atrial fibrillation (AF).

Methods

Cohort of 11,972 consecutive patients aged ≥65 years attending medical outpatient clinics in Hong Kong underwent AF screening using a handheld single-lead ECG (AliveCor) from Dec 2014 to Dec 2017 (NCT02409654). Repeated screening was performed in patients who had >1 clinic visit during the study period. Cohort was divided into 4 exposure groups: (i) new AF detected by initial screening (S1-AF); (ii) new AF detected by subsequent screening or clinically diagnosed during follow up (FU-AF); (iii) known AF and (iv) no initial or subsequent FU-AF (no AF). Exposure in the FU-AF group was handled as a time-dependent variable. All AF exposure groups were further stratified by oral anticoagulant (OAC) use at the end of FU. Cumulative incidence of ischemic stroke was compared between groups during a median FU period of 2.3 (IQR=1.7–3.3) years, using Fine and Gray regression accounting for death as competing risk and using no AF as reference.

Results

Of 11,972 subjects enrolled, 2,236 (18.7%) had known AF and 9,736 (81.3%) underwent 13,571 screening events during the study period. The yield of newly diagnosed AF on initial screening was 2.3% (n=223/9,736), with 71 new AF detected by subsequent screening. During FU, 2.3% (221/9,442) screen-negative patients were diagnosed with AF clinically. Compared to no AF, S1-AF without OAC had the highest ischemic stroke risk (subdistribution hazard ratio (SHR)=2.79; 1.47–5.27), then FU-AF without OAC (SHR=2.66; 1.21–5.82) and known AF without OAC (SHR=1.97; 1.50–2.57). All AF groups taking OAC had similar risk of ischemic stroke as no AF.

Conclusion

This is the first study to report the prognosis of AF detected by single timepoint screening. The prognosis is not benign. Both risks of stroke and benefits from anticoagulation therapy were similar between screen-detected and known AF.

Funding Acknowledgement

Type of funding source: None
Acute response to cardiac re-synchronization therapy: ventricular properties adaptation?
Authors: Degiovanni A , Gravellone M , Erbetta R , Dell' Era G , Marino P.N , Patti G
Published: November 2020

Background

Cardiac re-synchronization therapy (CRT) reduces mortality and hospitalization in patients with heart failure, reduced left ventricular ejection fraction (LVEF) and left bundle branch block (LBBB). However, there is no conclusive evidence on baseline parameters able to discriminate responder vs non-responder patients.

Purpose

In this study, we tested whether echocardiographic parameters describing LV dyssynchrony and efficiency may predict an acute LV recovery after CRT and whether lead position can modify such relationship.

Methods

We enrolled 65 consecutive patients (75% males, aged 71.2±10.5 years) referred for CRT according to current guidelines; 45% had an underlying ischaemic cardiopathy and 1/3 of them presented diabetes mellitus. We performed a CRT-off and CRT–on 2D and 3D echocardiography during devices optimization (time between programming change 10/12 min). We evaluated ventricular dyssynchrony by speckle-tracking analysis based on temporary uniformity of strain (TUS) 3D longitudinal and circumferential. We also derived non-invasive myocardial efficiency (Effic) by interaction between pressure work index (PWI), representing an estimation of myocardial oxygen consumption, and mechanical external work. We indicated as concordant those patients presenting a LV lead position (defined from a chest X-ray using 2 orthogonal views) in the same segment as the latest systolic 3D circumferential strain curves.

Results

In the CRT-on phase, a non-statistically significant raise in LVEF was observed [from 0.37 (0.28–0.46) to 0.41 (0.34–0.47), p=0.27]. No improvement in both longitudinal and circumferential 3D TUS was demonstrated during CRT-on (p=0.44 and 0.47, respectively). Conversely, the gain in Effic from CRT-off to CRT-on phase was overall significant (from 0.43±0.14 to 0.50±0.16; p<0.001). After switching to CRT-on, the increase in longitudinal 3D TUS was higher in concordant compared to discordant patients (from 0.83±0.08 to 0.87±0.07 vs 0.88±0.11 to 0.87±0.12, respectively), but without significant interaction (interaction p 0.24). No interaction was also found between variations of PWI after switching to CRT-on and LV lead position (concordant: from 12.99±4.18 to 12.84±2.99 ml/min/100g; discordant: from 13.58±3.89 to 13.95±3.97 ml/min/100g; interaction p 0.75).

Conclusions

Effic was overall acutely augmented during CRT-on phase in patients with LV dysfunction undergoing cardiac re-synchronization. In the acute phase, no significant relationship between LV changes in speckle-tracking analyses after CRT and LV lead position was found.

2-way ANOVA for myocardial efficiency

Funding Acknowledgement

Type of funding source: None
Endoscopic repair of atrial functional mitral regurgitation in heart failure: long-term effects
Authors: Balogh Z , Mizukami T , Bartunek J , Collet C , Beles M , Albano M , Katbeh A , Casselman F , Vanderheyden M , Van Camp G , Van Praet F , Penicka M
Published: November 2020

Introduction

In patients with heart failure and preserved ejection fraction (HFpEF), even mild atrial functional mitral regurgitation (AFMR) has been associated with poor outcome.

Objective

To describe long-term effects of endoscopic mitral valve (MV) repair on outcome in patients with HFpEF and AFMR.

Methods

The study population consisted of consecutive patients with HFpEF (LVEF ≥50%, H2FPEF score ≥5) and AFMR, who underwent isolated, minimally invasive (endoscopic), MV repair (MVRepair group) (n=131) or remained on standard of care (StanCare group) (n=139). Patients with coronary artery disease or organic MR were excluded. Patients were matched using inverse probability of treatment weighting. Primary objective was all-cause mortality or HFpEF readmissions.

Results

The median follow up was 5.03 years (IQR 2.6–7.9 years). In the MVRepair group, the perioperative, 30-day, 1- and 5-year mortality was 0, 1% and 12%, respectively. Additional 13 (10%) patients were readmitted for worsening HFpEF, while 2 (1%) individuals underwent redo MV surgery for recurrent MR. MVRepair compared with StanCare showed 21–29% (SE 6–8%) and 19–26% (SE 6–8%) absolute risk reduction of all-cause mortality and HFpEF readmissions, respectively (all p<0.05). MVRepair emerged as the strongest independent predictor of all-cause mortality (HR 0.16, 95% CI 0.07–0.34, p<0.001) and HFpEF readmissions (HR 0.21, 95% CI 0.09–0.51, p<0.001). At 5-year follow-up, in the MVRepair group, a total of 88% were alive and 80% were alive without readmission for HFpEF.

Conclusions

Endoscopic MV repair is associated with low perioperative mortality, high long-term efficacy and appears to improve clinical outcome in patients with AFMR and HFpEF.

Mortality and readmission for HF

Funding Acknowledgement

Type of funding source: None