bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract

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&lt;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

Abstract

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&lt;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

Abstract

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 &gt;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&lt;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

Abstract

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

Abstract

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&lt;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&lt;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

Abstract

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

Abstract

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 (&gt;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

Abstract

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

Abstract

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&lt;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&lt;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