Epicardial mapping as first intention approach for structural ventricular tachycardia ablation

Funding Acknowledgements

Type of funding sources: None.

Introduction

In several structural arrhythmogenic diseases that comprise intricate endocardial, intramural and epicardial substrates, endocardial ablation of ventricular tachycardia (VT) is not sufficient and epicardial ablation has lately become a complementary and necessary tool.

Purpose

To evaluate the clinical characteristics of patients (pts) most suitable for first intention epicardial VT ablation.

Methods

Single-center prospective study of consecutive pts with structural heart disease undergoing first intention epicardial VT mapping between August 2015 and June 2021. Decision for epicardial approach was based on the etiology, VT electrocardiogram (ECG) and cardiac magnetic resonance (CMR) results. Under general anesthesia, subxiphoid access using a Tuhoy needle was done using fluoroscopic guidance and with high-density epicardial mapping was performed. Epicardial ablation was performed if relevant arrhythmogenic findings were locally confirmed.

Results

First intention epicardial VT ablation was attempted in 18 pts (mean age 59.8±12 years,94% male) of whom 16 had non-ischemic dilated cardiomyopathy (NICM,idiopathic:11; post-myocardis:4; hereditary:1) and 2 had right ventricular arrhythmogenic cardiomyopathy. Mean LVEF was 33% and 79% had a previous ICD (53% in primary prevenon). 69% were referred for ablation due to arrhythmic storm (1pt in cardiogenic shock). Epicardial access was achieved in 17 pts (94%), without acute complications. In 35% pts with NICM the decision for epicardial approach was based on the detection of subepicardial CMR delayed-hyperenhancement and relevant epicardial arrhythmic substrate was confirmed by mapping in all cases. In 3 pts radiofrequency (RF) applicaons were not performed at epicardium, as no abnormal electrograms were locally detected, and an addional endocardial approach was prosecuted. The mean overall procedure and fluoroscopic time were 123 and 28min, respectively, with a mean RF application me of 51min. After the procedure 1pt required pericardial drainage due to inflammatory pericardial effusion. No other acute complications occurred. During a mean follow-up of 2.8±1.8 years, only 3pts (17%) had VT recurrence; 5pts (28%) died due to end-stage heart failure and 2pts (11%) underwent heart transplantation.

Conclusion

In NICM a first intention epicardial VT ablation performed by experienced operators/centers is efficient, particularly if guided by CMR findings,and presents a safety profile.

Combining plasma extracellular vesicle Let-7b-5p, miR-184 and circulating miR-22-3p levels for NSCLC diagnosis and drug resistance prediction

Low-dose computed tomography (LDCT) Non-Small Cell Lung (NSCLC) screening is associated with high false-positive rates, leading to unnecessary expensive and invasive follow ups. There is a need for minimally invasive approaches to improve the accuracy of NSCLC diagnosis. In addition, NSCLC patients harboring sensitizing mutations in epidermal growth factor receptor EGFR (T790M, L578R) are treated with Osimertinib, a potent tyrosine kinase inhibitor (TKI). However, nearly all patients develop TKI resistance. The underlying mechanisms are not fully understood. Plasma extracellular vesicle (EV) and circulating microRNA (miRNA) have been proposed as biomarkers for cancer screening and to inform treatment decisions. However, the identification of highly sensitive and broadly predictive core miRNA signatures remains a challenge. Also, how these systemic and diverse miRNAs impact cancer drug response is not well understood. Using an integrative approach, we examined plasma EV and circulating miRNA isolated from NSCLC patients versus screening controls with a similar risk profile. We found that combining EV (Hsa-miR-184, Let-7b-5p) and circulating (Hsa-miR-22-3p) miRNAs abundance robustly discriminates between NSCLC patients and high-risk cancer-free controls. Further, we found that Hsa-miR-22-3p, Hsa-miR-184, and Let-7b-5p functionally converge on WNT/βcatenin and mTOR/AKT signaling axes, known cancer therapy resistance signals. Targeting Hsa-miR-22-3p and Hsa-miR-184 desensitized EGFR-mutated (T790M, L578R) NSCLC cells to Osimertinib. These findings suggest that the expression levels of circulating hsa-miR-22-3p combined with EV hsa-miR-184 and Let-7b-5p levels potentially define a core biomarker signature for improving the accuracy of NSCLC diagnosis. Importantly, these biomarkers have the potential to enable prospective identification of patients who are at risk of responding poorly to Osimertinib alone but likely to benefit from Osimertinib/AKT blockade combination treatments.

Search for Relativistic Magnetic Monopoles with Eight Years of IceCube Data

We present an all-sky 90% confidence level upper limit on the cosmic flux of relativistic magnetic monopoles using 2886 days of IceCube data. The analysis was optimized for monopole speeds between 0.750c and 0.995c, without any explicit restriction on the monopole mass. We constrain the flux of relativistic cosmic magnetic monopoles to a level below 2.0×10^{-19}  cm^{-2} s^{-1} sr^{-1} over the majority of the targeted speed range. This result constitutes the most strict upper limit to date for magnetic monopoles with β≳0.8 and up to β∼0.995 and fills the gap between existing limits on the cosmic flux of nonrelativistic and ultrarelativistic magnetic monopoles.

P–532 Embryo quality needs to be considered as a main criterion when selecting mosaic embryos for transfer

Study question

Should we consider embryo quality as one of the most important criteria to follow when transferring a mosaic embryo?

Summary answer

Embryo quality is an implantation biomarker both for euploid and mosaic embryos, and also a determinant for selecting the most eligible mosaic for transfer.

What is known already

Several studies show the benefit of transferring mosaic embryos when there are no euploid embryos to transfer, and they still result in ongoing pregnancies and what is more important is that they result in healthy babies.

Studies and guidelines suggest prioritizing mosaic embryos based on maternal age, chromosomes impacted, percentage of aneuploidy, number of chromosomes involved, type of mosaic (simple vs complex, segmental vs complete, monosomy vs trisomy) but embryo quality is never part of these criteria.

Studies claim that mosaic implantation rate is lower than euploid embryos, but they never show if both populations are comparable in terms of quality.

Study design, size, duration

This is a retrospective observational study performed in a private centre between February 2018 and January 2020. The study includes the data analysis of 96 euploid blastocysts and 14 low risk mosaic blastocysts (defining low risk regarding chromosome syndromes and less than 50% level mosaicism). All transferred in single embryo transfer (SET) to 105 patients after PGT-A (mean maternal age 38,9 years).

The SET factor enables us to track the implantation outcome of all embryos.

Participants/materials, setting, methods

PGT-A with NGS technology was offered to patients of advanced maternal age and/or with repeated IVF failures. Trophectoderm biopsies were performed on day 5 and/or day 6 embryos, with laser assistance. Blastocyst morphology was scored in 3 groups: A: excellent (AA, AB, BA), B: good (BB), C: average and poor-quality embryos (BC, CB, CC). (Gardner-Schoolcraft classification)

Low risk mosaic embryo transfer was offered to patients with no euploid embryos to transfer.

Main results and the role of chance

We found no significant differences between both populations (euploid and mosaic embryos) in terms of embryo quality (Chi^2 p-value =0,0975) so we were able to compare the overall implantation of similar quality populations.

Despite euploid implantation being higher as described in most studies, no statistical differences (Chi^2 p-value = 0,4344) were found in terms of implantation rates between mosaic (57,0%) and euploid (67,6%) blastocysts during the same period. There are no differences between the mean age of both groups (39,7 vs 38,8 years, respectively).

The implantation rates for euploid blastocysts were 79,5% (n = 39), 62,7% (n = 51) and 33,3% (n = 6) in the A, B and C blastocyst quality groups, respectively, showing significative differences among the three groups.

The implantation rates of low-risk mosaic blastocysts were 100% (n = 3), 62,5% (n = 8) and 0,0% (n = 3) in the A, B and C blastocyst morphology groups, respectively, showing also still significant differences among the three groups despite the small population. (Chi^2 p-values according to implantation: Euploid =0,0434; Mosaic=0,0419)

We have also compared the three quality categories between both populations showing no significative differences (Chi^2 p-values according to quality: A = 0,4344; B = 0,9894; C = 0,2568), concluding that same quality embryos behave the same way despite being euploid or mosaic.

Limitations, reasons for caution

The study is limited by its retrospective nature and the low number of mosaic embryos transferred as they are the last option for transfer. Additionally, it is common to transfer more than one mosaic embryo to increase the chances of pregnancy, therefore losing implantation track.

Wider implications of the findings: Embryo quality has always been a strong biomarker predictable for implantation and this is also true for mosaic embryos as well. It is a simple concept, but we cannot compare implantation potential of euploid embryos with mosaic embryos without describing both populations in terms of quality.

Trial registration number

Not applicable

Do miRNAs Have a Role in Platelet Function Regulation?

MicroRNAs (miRNAs) are a class of non-coding RNAs known to repress mRNA translation and subsequent protein production. miRNAs are predicted to modulate many targets and are involved in regulating various cellular processes. Identifying their role in cell function regulation may allow circulating miRNAs to be used as diagnostic or prognostic markers of various diseases. Increasing numbers of clinical studies have shown associations between circulating miRNA levels and platelet reactivity or the recurrence of cardiovascular events. However, these studies differed regarding population selection, sample types used, miRNA quantification procedures, and platelet function assays. Furthermore, they often lacked functional validation of the miRNA identified in such studies. The latter step is essential to identifying causal relationships and understanding if and how miRNAs regulate platelet function. This review describes recent advances in translational research dedicated to identifying miRNAs' roles in platelet function regulation.

Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm

We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g-2 Experiment for the positive muon magnetic anomaly a_{μ}≡(g_{μ}-2)/2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency ω_{a} between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency ω[over ˜]_{p}^{'} in a spherical water sample at 34.7 °C. The ratio ω_{a}/ω[over ˜]_{p}^{'}, together with known fundamental constants, determines a_{μ}(FNAL)=116 592 040(54)×10^{-11} (0.46 ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both μ^{+} and μ^{-}, the new experimental average of a_{μ}(Exp)=116 592 061(41)×10^{-11} (0.35 ppm) increases the tension between experiment and theory to 4.2 standard deviations.

Outcome of treatment of MDR-TB or drug-resistant patients treated with bedaquiline and delamanid: Results from a large global cohort

The World Health Organization (WHO) recommends countries introduce new anti-TB drugs in the treatment of multidrug-resistant tuberculosis. The aim of the study is to prospectively evaluate the effectiveness of bedaquiline (and/or delamanid)- containing regimens in a large cohort of consecutive TB patients treated globally. This observational, prospective study is based on data collected and provided by Global Tuberculosis Network (GTN) centres and analysed twice a year. All consecutive patients (including children/adolescents) treated with bedaquiline and/or delamanid were enrolled, and managed according to WHO and national guidelines. Overall, 52 centres from 29 countries/regions in all continents reported 883 patients as of January 31st 2021, 24/29 countries/regions providing data on 100% of their consecutive patients (10-80% in the remaining 5 countries). The drug-resistance pattern of the patients was severe (>30% with extensively drug-resistant -TB; median number of resistant drugs 5 (3-7) in the overall cohort and 6 (4-8) among patients with a final outcome). For the patients with a final outcome (477/883, 54.0%) the median (IQR) number of months of anti-TB treatment was 18 (13-23) (in days 553 (385-678)). The proportion of patients achieving sputum smear and culture conversion ranged from 93.4% and 92.8% respectively (whole cohort) to 89.3% and 88.8% respectively (patients with a final outcome), a median (IQR) time to sputum smear and culture conversion of 58 (30-90) days for the whole cohort and 60 (30-100) for patients with a final outcome and, respectively, of 55 (30-90) and 60 (30-90) days for culture conversion. Of 383 patients treated with bedaquiline but not delamanid, 284 (74.2%) achieved treatment success, while 25 (6.5%) died, 11 (2.9%) failed and 63 (16.5%) were lost to follow-up.

Genomic information allows for more accurate breeding values for milkability in dual-purpose Italian Simmental cattle

Milkability is a trait related to the milking efficiency of an animal, and it is a component of the herd profitability. Due to its economic importance, milkability is currently included in the selection index of the Italian Simmental cattle breed with a weight of 7.5%. This lowly heritable trait is measured on a subjective scale from 1 to 3 (1 = slow, 3 = fast), and genetic evaluations are performed by pedigree-based BLUP. Genomic information is now available for some animals in the Italian Simmental population, and its inclusion in the genetic evaluation system could increase accuracy of breeding values and genetic progress for milkability. The aim of this study was to test the feasibility and advantages of having a genomic evaluation for this trait in the Italian Simmental population. Phenotypes were available for 131,308 cows. A total of 9,526 animals had genotypes for 42,152 loci; among the genotyped animals, 2,455 were cows with phenotypes, and the other were their relatives. The youngest cows with both phenotypes and genotypes (n = 900) were identified as selection candidates. Variance components and heritability were estimated using pedigree information, whereas genetic and genomic evaluations were carried out using BLUP and single-step genomic BLUP (ssGBLUP), respectively. In addition, a weighted ssGBLUP was assessed using genomic regions from a genome-wide association study. Evaluation models were validated using theoretical and realized accuracies. The estimated heritability for milkability was 0.12 ± 0.01. The mean theoretical accuracies for selection candidates were 0.43 ± 0.08 (BLUP) and 0.53 ± 0.06 (ssGBLUP). The mean realized accuracies based on linear regression statistics were 0.29 (BLUP) and 0.40 (ssGBLUP). No genomic regions were significantly associated with milkability, thus no improvements in accuracy were observed when using weighted ssGBLUP. Results indicated that genomic information could improve the accuracy of breeding values and increase genetic progress for milkability in Italian Simmental.

Processing Strategies to Obtain Highly Porous Silk Fibroin Structures with Tailored Microstructure and Molecular Characteristics and Their Applicability in Water Remediation

The present work reports on the control of silk fibroin (SF) porous structures performance through various processing methods. The study includes the analysis of two dissolving techniques (CaCl₂/H₂O/EtOH ternary and LiBr/H₂O binary solutions), three regeneration methods (gelation, lyophilization and gas foaming) and one post-processing (EtOH). In all the cases, followed steps lead to SF structures with porosity values above 94% and large surface areas. Also, results about samples microstructure, secondary organization, crystallinity and water behavior, reveal a direct correlation between processing and SF properties. Thanks to the achieved progress, the SF varying porous structures were evaluated for metalloids (As⁵⁺ and As³⁺) and heavy metals (Cr⁶⁺ and Cr³⁺) adsorption, observing a direct relationship between samples processing and ionic species adsorption ability. Thus, it is shown that the control of the properties of SF based porous structures through processing, represents a suitable and ecofriendly approach for the development of bio-based materials for environmental applications.

Different methylation signatures at diagnosis in patients with high-risk myelodysplastic syndromes and secondary acute myeloid leukemia predict azacitidine response and longer survival

BACKGROUND

Epigenetic therapy, using hypomethylating agents (HMA), is known to be effective in the treatment of high-risk myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) patients who are not suitable for intensive chemotherapy and/or allogeneic stem cell transplantation. However, response rates to HMA are low and there is an unmet need in finding prognostic and predictive biomarkers of treatment response and overall survival. We performed global methylation analysis of 75 patients with high-risk MDS and secondary AML who were included in CETLAM SMD-09 protocol, in which patients received HMA or intensive treatment according to age, comorbidities and cytogenetic.

RESULTS

Unsupervised analysis of global methylation pattern at diagnosis did not allow patients to be differentiated according to the cytological subtype, cytogenetic groups, treatment response or patient outcome. However, after a supervised analysis we found a methylation signature defined by 200 probes, which allowed differentiating between patients responding and non-responding to azacitidine (AZA) treatment and a different methylation pattern also defined by 200 probes that allowed to differentiate patients according to their survival. On studying follow-up samples, we confirmed that AZA decreases global DNA methylation, but in our cohort the degree of methylation decrease did not correlate with the type of response. The methylation signature detected at diagnosis was not useful in treated samples to distinguish patients who were going to relapse or progress.

CONCLUSIONS

Our findings suggest that in a subset of specific CpGs, altered DNA methylation patterns at diagnosis may be useful as a biomarker for predicting AZA response and survival.

KCNQ1 V141M and Short QT Syndrome: are we dealing with a different entity?

 

Short QT Syndrome (SQTS) is a highly malignant inherited primary electrical disease that is associated with ventricular arrhythmias and sudden cardiac death (SCD); despite this, some patients may present a different arrhythmic phenotype with supraventricular affection. One particular presentation can be notably separated from others. The V141M variant from the KCNQ1 gene frequently presents with fetal bradycardia, atrial fibrillation, sinus, and AV node dysfunction, but without a single reported event of ventricular arrhythmia.

To perform a literature review and pool analysis of SQTS cases, and compare patients with the V141M mutation in KCNQ1 to other SQTS cases to determine if we are dealing with a different electrical disorder.

We conducted a search in the Varsome, Mastermind, MEDLINE, PubMed, and ClinVar databases to identify SQTS patients and conduct a pooled analysis. Their age, gender, clinical presentation, ECG findings, genetic analysis, and follow-up assessment were collected for analysis. If the duration of the QT interval was not described, it was determined by direct measurements in published ECG. For the comparison between groups, SQTS patients, we separated into two main groups: Non-KCNQ1 V141M patients (Group 1) and positive KCNQ1 V141M mutation (Group 2). Categorical variables are expressed as percentages. The categorical variables were analyzed using chi-square or Fisher exact test when necessary.

We gathered 56 patients with a diagnosis of SQTS from 27 previous publications combined with one other case followed by the authors. A total of 13 (23.2%) patients presented with the V141M KCNQ1 mutation, the majority of KCNQ1 V141M patients were female (10 [77%]). Patients from group 1 had a significantly higher rate of familiar SCD (53.4% vs. 18.1%; P=0.04). Patients from the latter group have a significant history of SND when compared to the control group (36.3% vs. 0; P=0.001). The presence of SCD showed no significant difference between the two groups; nevertheless, the difference regarding ventricular arrhythmias is well represented (41.8% vs. 0; P=0.01). Both sinus and AV node dysfunction were present in almost all V141M patients when compared to the control group; a statistical significance was found (P = >0.001 for both instances). On the same regard, almost all patients from de V141M group presented SVA (84.6% vs 28.5%; P=0.001), specifically atrial fibrillation was present in all but 2 patients from the V141M group, which was significant (84.6% vs 24.3%; P = >0.001). Finally, fetal bradycardia was present in most of the members of this group, in contrast with the control group, with no patients with this characteristic (P = >0.001).

SQTS is a phenotypically heterogeneous disease with many genetic subtypes; we propose a differentiation between the common known presentations of this syndrome and the more defined phenotype of the KCNQ1 V141M mutation.

First Mexican patient with SQTS

Funding Acknowledgement

Type of funding source: None