P977Selective liner ablation according to the type of tachycardia induced after pulmonary vein isolation in single-procedure for long-standing persistent atrial fibrillation

Background

The most effective approach for long-standing persistent atrial fibrillation (LSPAF) ablation remained undetermined. Here, we hypothesized that selective linear ablation (SLA) according to the type of tachycardia induced by burst atrial pacing (BAP) after pulmonary venous isolation (PVI) in single-procedure reduces the recurrence.

Methods

A cohort of 66 LSPAF patients (Mean age 71.0±8.2 years, AF duration 40.5±58.8 months) who underwent PVI in single-procedure between April 2016 and November 2018 was evaluated.

Results

Any sustained atrial tachycardia (AT) or AF were not inducible by BAP after PVI in 21 patients (Non-inducible group, 31.8%, 71.3±7.9 years, 34.4±54.2 months). These patients underwent cavo-tricuspid isthmus (CTI) ablation after PVI. Forty-one patients underwent selective liner ablation according to the type of tachycardia induced by BAP after PVI (SLA group, 62.1%, 71.2±8.3 years, 39.3±55.6 months). Maccroreentry ATs (6 common atrial flutter, 5 AT originating from left atrial anterior wall, 2 peri-mitral atrial flutter, 1 roof-dependent atrial flutter) were induced by BAP in 14 patients of SLA group (73.2±19.7 years, 51.7±83.5 months). RF applications created the complete linear lesions to terminate maccroreentry ATs. Sustained AF was induced by BAP after PVI in 27 patients of SLA group (70.2±9.2 years, 32.9±31.2 months). These patients underwent posterior wall isolation (PWI) and CTI ablation. Unmappable AT was induced by BAP after PVI in 4 patients (Non-SLA group, 6.1%, 67.0±9.7 years, 84.5±105.6 months). These patients underwent PWI, CTI and mitral isthmus ablation on an empirical basis instead of SLA. Using a 90-day blanking period, the single-procedure Kaplan-Meier estimates of AT or AF event-free survival were 79% at 12 months. During follow-up (14.5±8.0 months), although 19 /21 (90.5%) of Non-inducible group patients and 33/41 (80.5%) of SLA group patients did not experience AT or AF recurrence, all of Non-SLA group patients experienced AF recurrence. There was no difference between Non-inducible group and SLA group in predicting recurrence of AT or AF (p=0.3). However, there was a difference when compared with Non-SLA group (each p<0.001). Non-SLA group was an independent powerful predictor resulting in recurrence of AF after adjusting for potential confounding factors (adjusted hazard ratio = 7.17; 95% confidence interval; 2.2–23.1, p=0.001, Wald χ2=10.9). Furthermore, in Kaplan-Meier survival curves for predicting AT or AF recurrence, Non-SLA group was the significant predictive marker of AT or AF recurrence (Log-Lank χ2=18.0, p<0.001).

Kaplan-Meier survival curves

Conclusions

In LSPAF patients without inducibility of any tachycardia after PVI, sinus rhythm was highly maintained without stepwise ablation other than CTI ablation. SLA reduced recurrence of AF in LSPAF patients with AT and AF induced after PVI. In addition, nonselective liner ablations for unmappable AT after PVI were less effective in LSPAF patients.

P5697J-wave elevation in the inferior leads is a predictor of lethal ventricular arrhythmia initiated by premature ventricular contractions with right bundle branch block and superior axis

Background

Lethal-ventricular-arrhythmia (VA) could be sometimes initiated by idiopathic Premature Ventricular Contractions (PVCs) originated form inferior wall. Furthermore, J-wave elevation in inferior leads was sometimes associated with lethal-VA. However, it was unclear the relationship between these PVCs and J-wave elevation in patients with lethal-VA.

Purpose

The aim of this study was to investigate the relationship between PVCs and J-wave elevation.

Methods and results

We studied 32 patients who underwent radiofrequency (RF) ablation of idiopathic PVCs with RBBB and superior axis. These PVCs were originating from inferior wall of left ventricular. Lethal-VA was defined as ventricular fibrillation (VF) or ventricular tachycardia (VT) with loss of consciousness (LOC). Among 32 patients, 3 had VF and 2 had VT with LOC. Other 27 had non-lethal-VA. Baseline clinical characteristics were not significantly difference between lethal and non-lethal-VA. The ratio of J-wave elevation in lethal-VA was significant higher as compared to those with non-lethal-VA (5/5 (100%) vs. 3/27 (11.1%), p<0.0001). Furthermore, no patients had recurrence of lethal-VA with J wave elevation in inferior leads after RF ablation of these PVCs with RBBB and superior axis,

Conclusions

We speculated that J-wave elevation in inferior leads might be a predictor of lethal-VA initiated by PVCs with RBBB and superior axis. RF ablation of these PVCs were useful method of treating lethal-VA.

Acknowledgement/Funding

None

Strong-correlation induced high-mobility electrons in Dirac semimetal of perovskite oxide

Electrons in conventional metals become less mobile under the influence of electron correlation. Contrary to this empirical knowledge, we report here that electrons with the highest mobility ever found in known bulk oxide semiconductors emerge in the strong-correlation regime of the Dirac semimetal of perovskite CaIrO₃. The transport measurements reveal that the high mobility exceeding 60,000 cm²V⁻¹s⁻¹ originates from the proximity of the Fermi energy to the Dirac node (ΔE < 10 meV). The calculation based on the density functional theory and the dynamical mean field theory reveals that the energy difference becomes smaller as the system approaches the Mott transition, highlighting a crucial role of correlation effects cooperating with the spin-orbit coupling. The correlation-induced self-tuning of Dirac node enables the quantum limit at a modest magnetic field with a giant magnetoresistance, thus providing an ideal platform to study the novel phenomena of correlated Dirac electron.

Electron correlation normally makes electrons less mobile, but it is still not clear when correlation becomes very strong in Dirac semimetals. Here, Fujioka et al. report a very high electron mobility exceeding 60,000 cm²V⁻¹s⁻¹ in correlated Dirac semimetal of perovskite CaIrO3, due to the enhanced electron correlation nearby the Mott transition.

Comparison of Sensitivity of Immunocomplex Capture Fluorescence Analysis for Detecting Donor-specific Anti-HLA Class II Antibodies in Kidney Transplant Patients

BACKGROUND

Immunocomplex capture fluorescence analysis (ICFA) detects donor-specific antihuman leukocyte antigen (HLA) antibodies (DSA), but the detection sensitivity of HLA class II antibodies using conventional ICFA is as low as 57%. The aim of the study was to improve the detection sensitivity of HLA class II antibodies by ICFA, and compare the ICFA results with the Luminex single-antigen bead test.

METHODS

Six DSA-negative kidney transplant donors and recipient pairs and 10 HLA class II DSA-positive pairs were included in the study. The detection sensitivity of modified ICFA was compared with conventional ICFA, and the ICFA results were compared with the Luminex single-antigen bead test.

RESULTS

The index value of modified ICFA was higher than that of conventional ICFA. The cutoff value of conventional ICFA was 30,686 (MFI), which was improved to 19,405 using modified ICFA. Regarding the HLA-DQ antibody, 5 samples found to be positive by Luminex single-antigen bead testing were all negative using modified ICFA. The reason for this discrepancy could be related to: (1) the difference in detection sensitivity; (2) the difference in HLA antigen surface expression between naive lymphocytes and synthetic beads; or (3) the structure of synthetic HLA DQ antigen on the Luminex single-antigen beads.

CONCLUSION

The index value of the modified ICFA was higher than that of conventional ICFA, and the detection sensitivity of HLA class II antibodies was improved by modified ICFA. Further assessment is necessary to clarify the reasons for divergence between ICFA and Luminex single-antigen bead test results.

Clinical significance of circulating miR-25-3p as a novel diagnostic and prognostic biomarker in osteosarcoma

Background

Emerging evidence has suggested that circulating microRNAs (miRNAs) in body fluids have novel diagnostic and prognostic significance for patients with malignant diseases. The lack of useful biomarkers is a crucial problem of bone and soft tissue sarcomas; therefore, we investigated the circulating miRNA signature and its clinical relevance in osteosarcoma.

Methods

Global miRNA profiling was performed using patient serum collected from a discovery cohort of osteosarcoma patients and controls and cell culture media. The secretion of the detected miRNAs from osteosarcoma cells and clinical relevance of serum miRNA levels were evaluated using in vitro and in vivo models and a validation patient cohort.

Results

Discovery screening identified 236 serum miRNAs that were highly expressed in osteosarcoma patients compared with controls, and eight among these were also identified in the cell culture media. Upregulated expression levels of miR-17-5p and miR-25-3p were identified in osteosarcoma cells, and these were abundantly secreted into the culture media in tumor-derived exosomes. Serum miR-25-3p levels were significantly higher in osteosarcoma patients than in control individuals in the validation cohort, with favorable sensitivity and specificity compared with serum alkaline phosphatase. Furthermore, serum miR-25-3p levels at diagnosis were correlated with patient prognosis and reflected tumor burden in both in vivo models and patients; these associations were more sensitive than those of serum alkaline phosphatase.

Conclusions

Serum-based circulating miR-25-3p may serve as a non-invasive blood-based biomarker for tumor monitoring and prognostic prediction in osteosarcoma patients.

Advanced capabilities for materials modelling with Quantum ESPRESSO

Quantum EXPRESSO is an integrated suite of open-source computer codes for quantum simulations of materials using state-of-the-art electronic-structure techniques, based on density-functional theory, density-functional perturbation theory, and many-body perturbation theory, within the plane-wave pseudopotential and projector-augmented-wave approaches. Quantum EXPRESSO owes its popularity to the wide variety of properties and processes it allows to simulate, to its performance on an increasingly broad array of hardware architectures, and to a community of researchers that rely on its capabilities as a core open-source development platform to implement their ideas. In this paper we describe recent extensions and improvements, covering new methodologies and property calculators, improved parallelization, code modularization, and extended interoperability both within the distribution and with external software.