P3755Left atrial enlargement as an independent risk factor for ischemic stroke in Japanese atrial fibrillation patients: pooled analysis of five major Japanese atrial fibrillation registries

Background

Atrial fibrillation (AF) increases the risk of ischemic stroke. It remains unknown whether left atrial diameter determined by routine trans-thoracic echocardiography is a risk factor for ischemic stroke in non-valvular AF (NVAF) patients.

Purpose

The aim of this study is to investigate the impact of left atrial enlargement (LAE) on the incidence of ischemic stroke in a large-scale cohort of Japanese NVAF patients.

Methods

We combined the data of 5 major AF registries in Japan, J-RHYTHM Registry, Fushimi AF Registry, Shinken Database, Keio interhospital Cardiovascular Studies, and Hokuriku AF Registry. After excluding patients without echocardiographic data, 7,672 NVAF patients were analyzed in the present study (mean age, 69.3±12.3 years; mean CHADS2 score, 1.6±1.3). We compared clinical characteristics and the incidence of ischemic stroke between NVAF patients with LAE (left atrial diameter >45 mm; LAE group) and those without (non-LAE group).

Results

The mean left atrial diameter was 43.1±8.6 mm, and the LAE group accounted for 40.0% (n=3,066) of the entire cohort. Compared with non-LAE group (60.0%, n=4,606), the LAE group was older (LAE vs. non-LAE; 70.3±12.0 vs. 68.0±12.5, p<0.01), more often non-paroxysmal type (73.7% vs. 32.1%, p<0.01), had higher CHADS2 (1.86±1.34 vs. 1.46±1.29, p<0.01) and CHA2DS2-VASc (3.02±1.83 vs. 2.53±1.78, p<0.01) scores, and more frequently received oral anticoagulant (72.9% vs. 55.0%, p<0.01).

During the median follow-up period of 774.5 days (interquartile range: 567–1466 days), ischemic stroke occurred in 241 patients (131 vs. 110 patients; 1.52 vs. 0.82 per 100 person-years). In Kaplan Meier analysis, LAE was associated with a higher incidence of ischemic stroke (unadjusted hazard ratio (HR): 1.83, 95% confidence interval (CI): 1.42–2.36; log rank p<0.01) (Figure). LAE was independently associated with increased risk of ischemic stroke (adjusted HR: 1.63, 95% CI: 1.25–2.11; p<0.01) after adjustment by the components of CHADS2 score and the use of oral anticoagulant, on multivariate Cox proportional hazard analysis.

Conclusion

In this large-scale cohort of Japanese patients with AF, LAE was an independent predictor of ischemic stroke, suggesting that this simple echocardiographic parameter could refine thromboembolic risk stratification of NVAF patients.

Acknowledgement/Funding

Japan Agency for Medical Research and Development, AMED

457Efficacy and safety of uninterrupted periprocedural edoxaban in patients undergoing catheter ablation for atrial fibrillation: Prospective KYU-RABLE study

Background/Introduction

Catheter ablation (CA) has been established as a first-line therapy in the treatment of non-valvular atrial fibrillation (NVAF), and uninterrupted direct oral anticoagulants (DOACs) have become mainstream for the management of periprocedural thromboembolic events. Since 2014, edoxaban has been used for anticoagulation therapy for AF in Japan. However, evidence for uninterrupted use of edoxaban during the periprocedural period of CA in NVAF patients is limited.

Purpose

KYU-RABLE is a prospective, multicenter, single-arm interventional study, conducted in 23 institutions in Japan to evaluate the efficacy and safety of uninterrupted periprocedural oral edoxaban in patients undergoing CA. The plasma concentration of edoxaban and its relation with plasma coagulative biomarker levels during the periprocedural period were also evaluated.

Methods

A total of 537 Japanese NVAF patients were enrolled in Japan from December 2017 to September 2018. Edoxaban 60mg (30 mg in patients indicated for dose adjustment) was administered once daily in the morning for at least 4 weeks before CA and continued for at least 4 weeks after CA. On the day of CA, edoxaban was administered immediately after confirmation of hemostat. The primary endpoint was the composite incidence of thromboembolism and major bleeding events during 4 weeks from the procedural day. Plasma concentration of edoxaban and plasma levels of coagulative biomarkers including D-dimer, soluble fibrin monomer complex (SFMC) and prothrombin fragment 1+2 (F1+2) were also measured.

Results

Among the total 513 patients who underwent CA, 75.2% had radiofrequency CA and 23.0% had cryoballoon CA. The majority of CA patients (65%) received edoxaban 60mg/day, while others (35%) received 30mg/day. As for the primary endpoint, one major bleeding (cardiac tamponade) event was observed and no thromboembolism occurred. Clinically relevant non-major bleeding events occurred in six patients (1.2%), the most were puncture site hemorrhage. The plasma concentration of edoxaban at CA was dependent upon the duration from last administration of edoxaban before CA. However, plasma levels of coagulative biomarkers (D-dimer, SFMC, F1+2) were maintained within appropriate range during the periprocedural period, irrespective of the edoxaban concentration. We also report changes of plasma levels of coagulative biomarkers in sub group analyses by CHADS2 scores and types of AF.

Conclusion

The KYU-RABLE study demonstrated the first evidence of the efficacy and safety of uninterrupted periprocedural edoxaban administered once daily on the morning for NVAF patients underwent CA. Edoxaban treatment was associated with a low risk of periprocedural bleeding and thromboembolic complications. Furthermore, these low event risks were considered to be associated with the maintained plasma level of coagulative biomarkers, regardless of the change in edoxaban plasma concentration.

Acknowledgement/Funding

Daiichi Sankyo Co. Ltd.

P5668A decision-support tool framework to predict adverse outcome in patients with atrial fibrillation: J-Rhythm registry substudy

Background

Atrial fibrillation (AF) is associated with increased mortality and morbidity. Modelling the risk of thrombosis, major bleeding and total mortality are often limited by the inadequate number of independent predictors.

Purpose

We compared the predictive accuracy of the decision-support tool framework and conventional risk score in AF patients.

Methods

We used data of AF patients enrolled into the nationwide AF registry. A random forest model was implemented to predict each outcome, and its predictive power was tested by a 5-fold cross-validation.

Results

We analyzed 7,937 patients with AF (age 70±10 years, female 31%). The type of AF was paroxysmal (37%), persistent (14%), and permanent (49%). The number of antithrombotic treatments were follows: warfarin only (n=5461), antiplatelet only (n=581), both warfarin and antiplatelet (n=1471) and no antithrombotic agents (424). The mean CHA2DS2-VASc score was 2.8±1.6 and HAS-BLED score was 2.7±1.2, respectively. We selected 20 from 50 clinical parameters and compared by the area-under-curve with the CHA2DS2-VASc score for thromboses and the HAS-BLED score for major bleeding. During the 2-year follow-up, 126 patients (1.6%) had thromboses, 140 (1.8%) had major bleeding, and 195 (2.5%) died. A random forest model had a higher value of the area-under-curve for predicting thromboses compared with the CHA2DS2-VASc (0.66 vs. 0.61, P<0.05), and had a significantly higher area-under-curve for major bleeding compared with the HAS-BLED (0.67 vs. 0.61, P<0.05). The area-under-curve for the all-cause mortality was 0.77.

Conclusions

A random forest model has a higher accuracy than conventional risk scheme in predicting thromboses and major bleeding, in addition to total mortality.

P1865Incidence and predictors of invasively-treated pericardial effusion during catheter ablation of atrial fibrillation in Japan

Purpose and method

Japanese Heart Rhythm Society requested electrophysiology centers to register the data of patients who underwent catheter ablation for atrial fibrillation (AF) in designated eight months from 2011 to 2017. We assessed the incidence and predictors of pericardial effusion (PE) as an early complication of AF ablation.

Results

More than two hundred EP centers reported the data of 13,233 AF ablation cases (age; 64.2±10.7 years, male; 72.6%, paroxysmal AF; 63.4%). Clinically significant complications occurred in 601 subjects (4.5%). Critical PE occurred in 116 patients (0.8%), while six of them required open-chest surgery. Overall complication rate did not show significant changes. In contrast, incidence of PE declined over time (2012:1.2%, 2017:0.5%, p=0.003). Multiple logistic regression analysis showed that seven factors were related with higher incidence of PE. Among these factors, primary extra-PV ablation and hypertrophic cardiomyopathy (HCM) were more remarkably associated with higher rate of PE (PVI[−] vs. PVI[+]= 9.0% vs. 0.8%, OR 12.3, p<0.001; HCM: [+] vs. [−] = 2.6% vs. 0.8%, OR 3.26, p=0.001). Comorbidity of coronary artery disease (CAD) and use of CARTO system were related with lower PE rate (CAD: [+] vs [−] = 0.2% vs. 0.9%, OR 0.22 [p=0.034], CARTO: [+] vs [−] = 0.7% vs. 1.2%, OR 0.52 [p=0.001]). None of cryobaloon ablation, gender, type of AF, center volume, periprocedural oral anticoagulant, or left atrial diameter was significantly related with the occurrence of PE.

Conclusions

Incidence of critical PE decreased recently. HCM and primary extra-PV ablation were outstanding predictors of critical PE.

Search for CP Violation in Neutrino and Antineutrino Oscillations by the T2K Experiment with 2.2×10^{21} Protons on Target

The T2K experiment measures muon neutrino disappearance and electron neutrino appearance in accelerator-produced neutrino and antineutrino beams. With an exposure of 14.7(7.6)×10^{20} protons on target in the neutrino (antineutrino) mode, 89 ν_{e} candidates and seven anti-ν_{e} candidates are observed, while 67.5 and 9.0 are expected for δ_{CP}=0 and normal mass ordering. The obtained 2σ confidence interval for the CP-violating phase, δ_{CP}, does not include the CP-conserving cases (δ_{CP}=0, π). The best-fit values of other parameters are sin^{2}θ_{23}=0.526_{-0.036}^{+0.032} and Δm_{32}^{2}=2.463_{-0.070}^{+0.071}×10^{-3}  eV^{2}/c^{4}.

Search for Boosted Dark Matter Interacting with Electrons in Super-Kamiokande

A search for boosted dark matter using 161.9 kt yr of Super-Kamiokande IV data is presented. We search for an excess of elastically scattered electrons above the atmospheric neutrino background, with a visible energy between 100 MeV and 1 TeV, pointing back to the Galactic center or the Sun. No such excess is observed. Limits on boosted dark matter event rates in multiple angular cones around the Galactic center and Sun are calculated. Limits are also calculated for a baseline model of boosted dark matter produced from cold dark matter annihilation or decay. This is the first experimental search for boosted dark matter from the Galactic center or the Sun interacting in a terrestrial detector.

A Remote-operated System to Map Radiation Dose in the Fukushima Daiichi Primary Containment Vessel

This paper describes the development of a submersible system based on a remote-operated vehicle coupled with radiation detectors to map the interior of the reactors at the Fukushima Daiichi nuclear power station. It has the aim oflocating fuel debris. The AVEXIS submersible vehicle used in this study has been designed as a low-cost, potentially disposable, inspection platform that is the smallest of its class and is capable of being deployed through a 150 mm diameter access pipe. To map the gamma-ray environment, a cerium bromide scintillator detector with a small form factor has been incorporated into the AVEXIS to identify radioactive isotopes via gamma-ray spectroscopy. This provides the combined system with the potential to map gamma-ray spectra and particle locations throughout submerged, contaminated facilities, such as Units 1, 2 and 3 of the Fukushima Daiichi nuclear power plant. The hypothesis of this research is to determine the sensitivity of the combined system in a submerged environment that replicates the combination of gamma radiation and water submersion but at lower dose rates.

Combined Analysis of Neutrino and Antineutrino Oscillations at T2K

T2K reports its first results in the search for CP violation in neutrino oscillations using appearance and disappearance channels for neutrino- and antineutrino-mode beams. The data include all runs from January 2010 to May 2016 and comprise 7.482×10^{20} protons on target in neutrino mode, which yielded in the far detector 32 e-like and 135  μ-like events, and 7.471×10^{20} protons on target in antineutrino mode, which yielded 4 e-like and 66  μ-like events. Reactor measurements of sin^{2}2θ_{13} have been used as an additional constraint. The one-dimensional confidence interval at 90% for the phase δ_{CP} spans the range (-3.13, -0.39) for normal mass ordering. The CP conservation hypothesis (δ_{CP}=0, π) is excluded at 90% C.L.

Effect of harvest time on some in vitro functional properties of hop polyphenols

Health benefits of hop polyphenols are well studied. In the present investigation, we examined the antioxidant activity, anti-nitric oxide (NO) production, and anti-adipocyte differentiation of polyphenols extracted from hops (HPP), harvested at different times for over 4years. Saaz hop variety from the Czech Republic was used in the in vitro assays. Twenty-three polyphenols were quantitatively analyzed using Orbitrap liquid chromatography-mass spectrometry (LC-MS), and their health promoting effects were assayed individually. Strong effects of low concentrations of HPP were observed in the above three assays. A significant increase in anti-adipocyte differentiation activity per unit weight of HPP was obtained in the early harvested samples. A significant difference in anti-NO production activity per unit weight of HPP was observed among the different harvest years. HPP significantly increased in early harvested samples. Our results suggest that some in vitro functional properties of hops vary with harvest time and year and are dependent on different polyphenols.

Measurement of Coherent π^{+} Production in Low Energy Neutrino-Carbon Scattering

We report the first measurement of the flux-averaged cross section for charged current coherent π^{+} production on carbon for neutrino energies less than 1.5 GeV, and with a restriction on the final state phase space volume in the T2K near detector, ND280. Comparisons are made with predictions from the Rein-Sehgal coherent production model and the model by Alvarez-Ruso et al., the latter representing the first implementation of an instance of the new class of microscopic coherent models in a neutrino interaction Monte Carlo event generator. We observe a clear event excess above background, disagreeing with the null results reported by K2K and SciBooNE in a similar neutrino energy region. The measured flux-averaged cross sections are below those predicted by both the Rein-Sehgal and Alvarez-Ruso et al.

Measurement of Muon Antineutrino Oscillations with an Accelerator-Produced Off-Axis Beam

T2K reports its first measurements of the parameters governing the disappearance of ν[over ¯]_{μ} in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν[over ¯]_{μ} beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν[over ¯]_{μ} survival probability is expected to be minimal. Using a data set corresponding to 4.01×10^{20} protons on target, 34 fully contained μ-like events were observed. The best-fit oscillation parameters are sin^{2}(θ[over ¯]_{23})=0.45 and |Δm[over ¯]_{32}^{2}|=2.51×10^{-3}  eV^{2} with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10^{-3}  eV^{2}, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the ν_{μ} disappearance parameters measured by T2K.

Antioxidant Activity of Phenolic Compounds from Fava Bean Sprouts

Fava beans are eaten all over the world and recently, marketing for their sprouts began in Japan. Fava bean sprouts contain more polyphenols and l-3,4-dihydroxyphenylalanine (l-DOPA) than the bean itself. Our antioxidant screening program has shown that fava bean sprouts also possess a higher antioxidant activity than other commercially available sprouts and mature beans. However, the individual constituents of fava bean sprouts are not entirely known. In the present study, we investigated the phenolic compounds of fava bean sprouts and their antioxidant activity. Air-dried fava bean sprouts were treated with 80% methanol and the extract was partitioned in water with chloroform and ethyl acetate. HPLC analysis had shown that the ethyl acetate-soluble parts contained phenolic compounds, separated by preparative HPLC to yield 5 compounds (1-5). Structural analysis using NMR and MS revealed that the compounds isolated were kaempferol glycosides. All isolated compounds had an α-rhamnose at the C-7 position with different sugars attached at the C-3 position. Compounds 1-5 had β-galactose, β-glucose, α-rhamnose, 6-acetyl-β-galactose and 6-acetyl-β-glucose, respectively, at the C-3 position. The amount of l-DOPA in fava bean sprouts was determined by the quantitative (1) H NMR technique. The l-DOPA content was 550.45 mg ± 11.34 /100 g of the raw sprouts. The antioxidant activities of compounds 2-5 and l-DOPA were evaluated using the 2,2-diphenyl-1-picrylhydrazyl scavenging assay. l-DOPA showed high antioxidant activity, but the isolated kaempferol glycosides showed weak activity. Therefore, it can be suggested that l-DOPA contributed to the antioxidant activity of fava bean sprouts.

Search for Nucleon and Dinucleon Decays with an Invisible Particle and a Charged Lepton in the Final State at the Super-Kamiokande Experiment

Search results for nucleon decays p→e^{+}X, p→μ^{+}X, n→νγ (where X is an invisible, massless particle) as well as dinucleon decays np→e^{+}ν, np→μ^{+}ν, and np→τ^{+}ν in the Super-Kamiokande experiment are presented. Using single-ring data from an exposure of  273.4  kton·yr, a search for these decays yields a result consistent with no signal. Accordingly, lower limits on the partial lifetimes of τ_{p→e^{+}X}>7.9×10^{32} yr, τ_{p→μ^{+}X}>4.1×10^{32} yr, τ_{n→νγ}>5.5×10^{32} yr, τ_{np→e^{+}ν}>2.6×10^{32}  yr, τ_{np→μ^{+}ν}>2.2×10^{32} yr, and τ_{np→τ^{+}ν}>2.9×10^{31} yr at a 90% confidence level are obtained. Some of these searches are novel.