WHO/ICC Classification for Myelodysplastic Neoplasms/Syndromes Performs Better for Subtype Cytomorphological Diagnosis?

The International Consensus Classification of Myeloid Neoplasms and Acute Leukemias (ICC) and the 5th edition of the WHO classification (WHO 2022) have refined the diagnosis of myelodysplastic syndromes (MDS). Both classifications segregate MDS subtypes based on molecular or cytogenetic findings but rely on the subjective assessment of blast cell percentage and dysplasia in hematopoietic cell lineages. This study aimed to evaluate interobserver concordance among 13 cytomorphologists from eight hospitals in assessing blast percentages and dysplastic features in 44 MDS patients. The study found fair interobserver agreement for the PB blast percentage and moderate agreement for the BM blast percentage, with the best concordance in cases with <5% BM blasts and >10% BM blasts. Monocyte count agreement was fair, and dysplasia assessment showed moderate concordance for megakaryocytic lineage but lower concordance for erythroid and granulocytic lineages. Overall, interobserver concordance for MDS subtypes was moderate across all classifications, with slightly better results for WHO 2022. These findings highlight the ongoing need for morphological evaluation in MDS diagnosis despite advances in genetic and molecular techniques. The study supports the blast percentage ranges established by the ICC but suggests refining BM blast cutoffs. Given the moderate interobserver concordance, a unified classification approach for MDS is recommended.

Hereditary angioedema in Spain: medical care and patient journey

BACKGROUND

Hereditary angioedema due to C1 inhibitor deficiency (HAE-C1INH) is a genetic rare disease characterized by recurrent, transient and unpredictable episodes of cold, non-pruriginous oedema without associated urticaria. The characteristics of the disease have a considerable impact on the quality of life of patients. The aim of this study was to increase understanding of the patient journey of HAE in Spain.

METHODS

A multidisciplinary committee of 16 HAE experts (allergy, immunology, emergency department, hospital pharmacy and nursing) and 3 representatives of the Spanish Hereditary Angioedema Patient Association (AEDAF) who were patients or caregivers participated in the study. A review of the publications on HAE treatment was performed. Semi-structured interviews were performed to HAE experts, patients, or caregivers. Three meetings with the experts, patients and caregivers were held to share, discuss, and validate data obtained from literature and interviews and to build the model.

RESULTS

Throughout the project, the patient journey has been drawn up, dividing it into the stages of pre-diagnosis, diagnosis and treatment/follow-up. Some areas for improvement have been identified. Firstly, there is a need to enhance awareness and training on HAE among healthcare professionals, with a particular emphasis on primary care and emergency department personnel. Secondly, efforts should be made to minimize patient referral times to allergy/immunology specialists, ensuring timely access to appropriate care. Thirdly, it is crucial to encourage the study of the relatives of diagnosed patients to early identify potential cases. Fourthly, equitable access to self-administered treatments should be ensured, facilitated by systems that enable medication delivery at home and proper education and training for patients. Equitable access to long-term prophylactic treatment should also be prioritized for all patients in need. To standardize HAE management, the development of consensus guidelines that reduce variability in clinical practice is essential. Lastly, promoting research studies to enhance knowledge of the disease and align its treatment with new developments in the healthcare field should be encouraged.

CONCLUSIONS

The knowledge of the patient journey in HAE allowed us to identify improvement areas with the final aim to optimize the disease management.

Comparing R-Bendamustine vs. R-CHOP Plus Maintenance Therapy as First-Line Systemic Treatment in Follicular Lymphoma: A Multicenter Retrospective GELTAMO Study

Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) and R-bendamustine (R-B) are the most common frontline treatment strategies for advanced-stage follicular lymphoma (FL). After R-CHOP induction therapy, using rituximab for maintenance therapy notably improves outcomes; however, whether this can be achieved by using the same approach after R-B therapy is still being determined. This retrospective analysis compared 476 FL patients from 17 GELTAMO centers who received R-based regimens followed by rituximab maintenance therapy for untreated advanced-stage FL. The complete response rate at the end of induction was higher with R-B and relapses were more frequent with R-CHOP. During induction, cytopenias were significantly more frequent with R-CHOP and so was the use of colony-stimulating factors. During maintenance therapy, R-B showed more neutropenia and infectious toxicity. After a median follow-up of 81 months (95% CI: 77-86), the 6-year rates of progression-free survival (PFS) were 79% (95% CI: 72-86) for R-bendamustine vs. 67% (95% CI: 61-73) for R-CHOP (p = 0.046), and 6-year overall survival (OS) values were 91% (95% CI: 86-96) for R-B vs. 91% (95% CI: 87-94) for R-CHOP (p = 0.49). In conclusion, R-B followed by rituximab maintenance therapy in patients with previously untreated FL resulted in significantly longer PFS than R-CHOP, with older patients also benefiting from this treatment without further toxicity. Adverse events during maintenance were more frequent with R-B without impacting mortality.

Studying the impacts of test condition and nonoptimal positioning of the sensors on the accuracy of the in-situ U-value measurement

The non-destructive thermal characterization of building envelopes relies significantly on various factors such as climate conditions, monitoring devices used, indoor environment, and conditioning systems. In the case of both the temperature-based method (TBM) and heat flux meter (HFM) approaches, U-value is determined considering the ideal condition of steady state. However, it is challenging to accurately define the true thermal condition of buildings when monitoring is affected by inherent uncertainties of the chosen approach and inadequate instrumentation of building envelopes. This paper presents the outcomes of an experimental campaign, that aimed to evaluate the impact of incorrectly positioned exterior sensors, on the precision of U-value measurements. This study simultaneously employed the TBM and HFM approaches. To enhance the accuracy of the results, rigorous outlier detection and statistical analysis were employed on the data collected from three autonomous monitoring systems. The findings of this study revealed that the applied data analysis yielded more satisfactory results for the TBM approach compared to HFM. However, regardless of the approach used, the effectiveness of outlier detection relied heavily on the accuracy of the monitoring systems. When removing an individual outlier, the monitoring systems characterized with higher accuracies provided U-values that were closer to the theoretical values, than less accurate ones.

Differential Effect of Targeted Temperature Management Between 32 °C and 36 °C Following Cardiac Arrest According to Initial Severity of Illness: Insights From Two International Data Sets

BACKGROUND

Recent guidelines have emphasized actively avoiding fever to improve outcomes in patients who are comatose following resuscitation from cardiac arrest (ie, out-of-hospital cardiac arrest). However, whether targeted temperature management between 32 °C and 36 °C (TTM32-36) can improve neurologic outcome in some patients remains debated.

RESEARCH QUESTION

Is there an association between the use of TTM32-36 and outcome according to severity assessed at ICU admission using a previously derived risk score?

STUDY DESIGN AND METHODS

Data prospectively collected in the Sudden Death Expertise Center (SDEC) registry (France) between May 2011 and December 2017 and in the Resuscitation Outcomes Consortium Continuous Chest Compressions (ROC-CCC) trial (United States and Canada) between June 2011 and May 2015 were used for this study. Severity at ICU admission was assessed through a modified version of the Cardiac Arrest Hospital Prognosis (mCAHP) score, divided into tertiles of severity. The study explored associations between TTM32-36 and favorable neurologic status at hospital discharge by using multiple logistic regression as well as in tertiles of severity for each data set.

RESULTS

A total of 2,723 patients were analyzed in the SDEC data set and 4,202 patients in the ROC-CCC data set. A favorable neurologic status at hospital discharge occurred in 728 (27%) patients in the French data set and in 1,239 (29%) patients in the North American data set. Among the French data set, TTM32-36 was independently associated with better neurologic outcome in the tertile of patients with low (adjusted OR, 1.63; 95% CI, 1.15-2.30; P = .006) and high (adjusted OR, 1.94; 95% CI, 1.06-3.54; P = .030) severity according to mCAHP at ICU admission. Similar results were observed in the North American data set (adjusted ORs of 1.36 [95% CI, 1.05-1.75; P = .020] and 2.42 [95% CI, 1.38-4.24; P = .002], respectively). No association was observed between TTM32-36 and outcome in the moderate groups of the two data sets.

INTERPRETATION

TTM32-36 was significantly associated with a better outcome in patients with low and high severity at ICU admission assessed according to the mCAHP score. Further studies are needed to evaluate individualized temperature control following out-of-hospital cardiac arrest.

Cell Senescence-Related Pathways Are Enriched in Breast Cancer Patients With Late Toxicity After Radiotherapy and Low Radiation-Induced Lymphocyte Apoptosis

Background

Radiation-induced late effects are a common cause of morbidity among cancer survivors. The biomarker with the best evidence as a predictive test of late reactions is the radiation-induced lymphocyte apoptosis (RILA) assay. We aimed to investigate the molecular basis underlying the distinctive RILA levels by using gene expression analysis in patients with and without late effects and in whom we had also first identified differences in RILA levels.

Patients and Methods

Peripheral blood mononuclear cells of 10 patients with late severe skin complications and 10 patients without symptoms, selected from those receiving radiotherapy from 1993 to 2007, were mock-irradiated or irradiated with 8 Gy. The 48-h response was analyzed in parallel by RILA assay and gene expression profiling with Affymetrix microarrays. Irradiated and non-irradiated gene expression profiles were compared between both groups. Gene set enrichment analysis was performed to identify differentially expressed biological processes.

Results

Although differentially expressed mRNAs did not reach a significant adjusted p-value between patients suffering and not suffering clinical toxicity, the enriched pathways indicated significant differences between the two groups, either in irradiated or non-irradiated cells. In basal conditions, the main differentially expressed pathways between the toxicity and non-toxicity groups were the transport of small molecules, interferon signaling, and transcription. After 8 Gy, the differences lay in pathways highly related to cell senescence like cell cycle/NF-κB, G-protein-coupled receptors, and interferon signaling.

Conclusion

Patients at risk of developing late toxicity have a distinctive pathway signature driven by deregulation of immune and cell cycle pathways related to senescence, which in turn may underlie their low RILA phenotype.

SARS-CoV-2-reactive antibody detection after SARS-CoV-2 vaccination in hematopoietic stem cell transplant recipients: Prospective survey from the Spanish Hematopoietic Stem Cell Transplantation and Cell Therapy Group

This is a multicenter prospective observational study that included a large cohort (n = 397) of allogeneic (allo‐HSCT; (n = 311) and autologous (ASCT) hematopoietic stem cell transplant (n = 86) recipients who were monitored for antibody detection within 3–6 weeks after complete severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) vaccination from February 1, 2021, to July 20, 2021. Most patients (n = 387, 97.4%) received mRNA‐based vaccines. Most of the recipients (93%) were vaccinated more than 1 year after transplant. Detectable SARS‐CoV‐2‐reactive antibodies were observed in 242 (78%) of allo‐HSCT and in 73 (85%) of ASCT recipients. Multivariate analysis in allo‐HSCT recipients identified lymphopenia < 1 × 10⁹/ml (odds ratio [OR] 0.33, 95% confidence interval [95% CI] 0.16–0.69, p = .003), active graft versus host disease (GvHD; OR 0.51, 95% CI 0.27–0.98, p = .04) and vaccination within the first year of transplant (OR 0.3, 95% CI 0.15–0.9, p = .04) associated with lower antibody detection whereas. In ASCT, non‐Hodgkin's lymphoma (NHL; OR 0.09, 95% CI 0.02–0.44, p = .003) and active corticosteroid therapy (OR 0.2, 95% CI 0.02–0.87, p = .03) were associated with lower detection rate. We report an encouraging rate of SARS‐CoV‐2‐reactive antibodies detection in these severe immunocompromised patients. Lymphopenia, GvHD, the timing of vaccine, and NHL and corticosteroids therapy should be considered in allo‐HSCT and ASCT, respectively, to identify candidates for SARS‐CoV‐2 antibodies monitoring.

Severe infections in patients with lymphoproliferative diseases treated with new targeted drugs: A multicentric real-world study

Background

Lymphoid neoplasms treatment has recently been renewed to increase antitumor efficacy and conventional chemotherapies toxicities. Limited data have been published about the infection risk associated with these new drugs, therefore this study analyzes the infectious complications in patients with lymphoproliferative diseases (LPD) treated with monoclonal antibodies (obinutuzumab, ofatumumab, brentuximab, nivolumab, or pembrolizumab), BTK inhibitors (ibrutinib and acalabrutinib), PI3K inhibitors (idelalisib) and BCL2 inhibitors (venetoclax).

Methods

Multicenter retrospective study of 458 LPD patients treated with targeted therapies in real‐life setting, in 18 Spanish institutions, from the time of their commercial availability to August 2020.

Results

Severe infections incidence was 23% during 17‐month median follow‐up; cumulative incidence was higher in the first 3–6 months of targeted drug treatment and then decreased. The most frequent etiology was bacterial (54%). Nine (6%) Invasive fungal infections (IFI) were observed, in its majority in chronic lymphocytic leukemia (CLL) patients treated predominantly with ibrutinib. Significant risk factors for severe infection were: severe lymphopenia (p = 0.009, OR 4.7, range 1.3–1.7), combined targeted treatment vs single agent treatment (p = 0.014 OR 2.2 range 1.1–4.2) and previous rituximab (p = 0.03 OR 1.8, range 1.05–3.3). Infection‐related mortality was 6%. In 22% of patients with severe infections, definitive discontinuation of the targeted drug was observed.

Conclusion

A high proportion of patients presented severe infections during follow‐up, with non‐negligible attributable mortality, but infection incidence is not superior to the one observed during the chemotherapy era. In selected cases with specific risk factors for infection, antimicrobial prophylaxis should be considered.

The Impact of Mindfulness Training on Police Officer Stress, Mental Health, and Salivary Cortisol Levels

Unaddressed occupational stress and trauma contribute to elevated rates of mental illness and suicide in policing, and to violent and aggressive behavior that disproportionately impacts communities of color. Emerging evidence suggests mindfulness training with police may reduce stress and aggression and improve mental health, but there is limited evidence for changes in biological outcomes or the lasting benefits of mindfulness training. We conducted a randomized controlled trial (RCT) of 114 police officers from three Midwestern U.S. law enforcement agencies. We assessed stress-related physical and mental health symptoms, blood-based inflammatory markers, and hair and salivary cortisol. Participants were then randomized to an 8-week mindfulness intervention or waitlist control (WLC), and the same assessments were repeated post-intervention and at 3-month follow-up. Relative to waitlist control, the mindfulness group had greater improvements in psychological distress, mental health symptoms, and sleep quality post-training, gains that were maintained at 3-month follow-up. Intervention participants also had a significantly lower cortisol awakening response (CAR) at 3-month follow-up relative to waitlist control. Contrary to hypotheses, there were no intervention effects on hair cortisol, diurnal cortisol slope, or inflammatory markers. In summary, an 8-week mindfulness intervention for police officers led to self-reported improvements in distress, mental health, and sleep, and a lower CAR. These benefits persisted (or emerged) at 3-month follow-up, suggesting that this training may buffer against the long-term consequences of chronic stress. Future research should assess the persistence of these benefits over a longer period while expanding the scope of outcomes to consider the broader community of mindfulness training for police.

Clinical Trial Registration: ClinicalTrials.gov#NCT03488875.

Helios negative Regulatory T-cells as a key factor of immune tolerance in non-allergic beekeepers

BACKGROUND AND OBJECTIVE

Background: Although exposure to stings has been identified as the leading risk factor for anaphylaxis due to Hymenoptera venom allergy, professional beekeepers receive hundreds yearly without developing systemic reactions. Objective: This study aims to analyse the mechanisms underlying bee venom tolerance in beekeepers.

METHODS

A cross-sectional study was conducted. Participants were recruited and classified into three groups: allergic patients (AP) experiencing systemic reactions after bee stings, with a positive intradermal test and specific IgE (sIgE) to Apis mellifera venom (AmV); tolerant beekeepers (TBK) receiving ≥50 stings/year; and healthy non-exposed controls (HC). Serum levels of sIgE and specific IgG4 (sIgG4) to AmV, rApi m 1, rApi m 2, rApi m 3, Api m 4, rApi m 5 and rApi m10, as well as AmV-induced basophil degranulation, percentage of T-cell subsets, regulatory T-cells (Treg cells) and IL-10 production, were measured.

RESULTS

APs had high levels of sIgE to AmV and all its allergic components (p<0.001) together with a high basophil activation rate (p<0.001) compared to TBKs. Conversely, compared to APs, TBKs showed higher levels of sIgG4 (p<0.001) and IL-10 (p<0.001) as well as an enhanced CTLA-4+ Treg population (p=0.001), expanded Helios- Treg (p<0.003), and reduced T-helper 1 (p=0.008), T-helper 2 (p=0.004) and T-helper 17 (p=0.007) subsets.

CONCLUSIONS

A different profile, strongly marked by Treg activity, was found in TBKs. This natural tolerance would be led by the expansion of inducible Helios-Treg cells at a peripheral level. Helios-Treg population could be a novel candidate biomarker useful for monitoring tolerance.

131 In&nbsp;vitro nuclear maturation and blastocyst developmental rates after intracytoplasmic sperm injection of equine oocytes held for 24&thinsp;h at room temperature in Tyrode&rsquo;s albumin lactate pyruvate-Hepes (TALP-h) or in a commercial embryo holding medium

The interest in equine intracytoplasmic sperm injection (ICSI) for commercial and research applications has rapidly increased. Shipping immature oocytes at room temperature has been proven successful, and to identify the optimal conditions for holding oocytes, several mediums are being tested. The aim of this study was to compare the effect of holding equine oocytes in Tyrode’s albumin lactate pyruvate-Hepes (TALP-h, Bavister and Yanagimachi 1977 Biol. Reprod. 16, 228-237) medium or in commercial embryo holding medium (EHM, Syngro® Holding) on invitro nuclear maturation rates and pre-implantation embryo development after ICSI. Cumulus–oocyte complexes (COCs) were recovered from ovaries of slaughtered mares and assigned randomly in 2-mL cryovials with TALP-h or EHM, with a maximum of 30 oocytes per cryovial. COCs were shipped to the ICSI laboratory at 20 to 25°C for 24 to 28h followed by IVM for 24h in a humidified atmosphere of 5% CO2 in air at 38.5°C. Maturation medium was TCM-199 with 10% fetal bovine serum, 1μL mL−1 insulin-transferrin-selenium, 1mM sodium pyruvate, 100mM cysteamine, and 0.1mg mL−1 FSH. After mechanical cumulus cell removal, nuclear maturation rate was assessed using a stereomicroscope. Oocytes with an intact oolemma and extrusion of the first polar body (PB) were classified as mature, oocytes without a visible PB were considered immature, and oocytes without an intact oolemma were considered degenerate. Matured oocytes were subjected to ICSI without piezo-drill system (one proved stallion) in 20-μL droplets of TALP-h with a 7-μm glass sharp micropipette in an inverted microscope (Nikon Eclipse TE-300 microscope) using hydraulic micromanipulators (Narishige, Medical Systems). Presumptive ICSI zygotes were cultured in DMEM F12/Global Total® with 6% fetal bovine serum for 9 days at 38.5°C in a humidified atmosphere of 5% O2 and 5% CO2 in air. On Day 5 of culture, cleavage was recorded and medium was refreshed. Blastocysts rates were recorded on Day 7 and 9 of culture. Invitro nuclear maturation rates are shown in Table 1. We observed a significantly higher proportion of immature oocytes in the EHM group compared with the TALP-h group. After ICSI of some matured oocytes of each group, no significant differences were observed in cleavage or blastocyst rate (Table 1). Our results suggest that either TALP-h or commercial embryo holding medium are suitable for oocyte shipping and to support blastocyst development after ICSI. Table 1. Invitro nuclear maturation rates and pre-implantation embryo development after intracytoplasmic sperm injection (ICSI) Maturation rates Medium Oocytes Mature [n (%)] Immature [n (%)] Degenerate [n (%)] TALP-h 315 173 (54.9) 26 (8.3)a 116 (36.8) EHM 273 132 (48.4) 55 (20.1)b 86 (31.5) Total 588 305 (51.9) 81 (13.8) 202 (34.4) Embryo development ICSI (n) Cleaved [n (%)] Day 7 Blastocyst [n (%)] Day 9 Blastocyst [n (%)] TALP-h 35 23 (65.7) 7 (20) 9 (25.7) EHM 26 19 (73.1) 3 (11.5) 5 (19.2) Total 61 42 (68.9) 10 (16.4) 14 (23) a,bDifferent superscript letters indicate statistical significance (Fisher’s exact test, P&lt;0.05).

Antiviral drugs targeting endosomal membrane proteins inhibit distant animal and human pathogenic viruses

The endocytic pathway is a common strategy that several highly pathogenic viruses use to enter into the cell. To demonstrate the usefulness of this pathway as a common target for the development of broad-spectrum antivirals, the inhibitory effect of drug compounds targeting endosomal membrane proteins were investigated. This study entailed direct comparison of drug effectiveness against animal and human pathogenic viruses, namely Ebola (EBOV), African swine fever virus (ASFV), and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

A panel of experimental and FDA-approved compounds targeting calcium channels and PIKfyve at the endosomal membrane caused potent reductions of entry up to 90% in SARS-CoV-2 S-protein pseudotyped retrovirus. Similar inhibition was observed against transduced EBOV glycoprotein pseudovirus and ASFV. SARS-CoV-2 infection was potently inhibited by selective estrogen receptor modulators in cells transduced with pseudovirus, among them Raloxifen inhibited ASFV with very low 50% inhibitory concentration. Finally, the mechanism of the inhibition caused by the latter in ASFV infection was analyzed.

Overall, this work shows that cellular proteins related to the endocytic pathway can constitute suitable cellular targets for broad range antiviral compounds.

Rheological fingerprinting as an effective tool to guide development of personal care formulations

OBJECTIVE

Conventional rheological techniques in the linear viscoelastic region provide insights about the spatial configuration of the microstructural components of personal care formulations in their 'at-rest' state. However, they fail to describe the textural experience associated with large and fast deformations during daily consumer application. In this study we present a non-conventional rheological technique-large amplitude oscillatory shear (LAOS)-for probing the transformation of a material during its application. This technique is proposed a practical tool for formulators in their efforts to design products with desired textural attributes.

METHODS

A non-linear rheological technique termed LAOS was utilized to capture the textural expression perceived by consumers. Lissajous plots (stress vs. strain or strain rate) provide a fingerprint of the formula and are utilized to both analyse the thickening mechanism and monitor the influence of various parameters, such as the chemistry, molecular properties, colloidal parameters and processing conditions.

RESULTS

In this study, we showcased several approaches for modifying the texture of personal care formulations and show the influence of various parameters on the characteristics of the Lissajous curves and their relation to sensorial perception. This fingerprinting technique shows that increasing the molecular weight or hydrophobic modification boosts the elasticity and thickening efficiency of a given polymer. Differences in the chemistry of rheological ingredients also influence the characteristic Lissajous fingerprint. In high concentration surfactant systems, which tend to form worm-like micelles, their unique Lissajous fingerprints indicate structure rebuild because of fast kinetics at large but slow deformations. Analysis of lamellar gel-based hair conditioner formulations demonstrates the unique high yield stress of these types of materials, accompanied by the fast breakdown transition from a solid to viscous structure because of their crystalline lamellar gel structure.

CONCLUSION

The LAOS technique presented in this article is intended to better capture the textural expression perceived by consumers. Lissajous plots-generated from the LAOS experimental data-provide a fingerprint of the tested formula and are utilized to both analyse the thickening mechanism and monitor the influence of various parameters, such as the chemistry and molecular weight of the thickener, pH of the formula medium and influence of other ingredients in the formula (surfactants, emulsifiers, etc.).

P959Influence of complex reentrant atrial circuits on tachycardia cycle length

Funding Acknowledgements

NA

OnBehalf

NA

Background

Ablation of left atrial reentrant tachycardias (ART) is challenging since they usually occur in the setting of complex diseased atrial tissue either in patients with structural heart disease or after ablation of atrial fibrillation. In these cases, scarred tissue or previous ablation lines make the circuits more complex. We have developed a mapping approach in which an activation map that only contains the active circuit is generated from entrainment maneuvers.

Purpose

To describe the electrophysiological characteristics of the circuits in patients with structural heart disease and previous left atrial ablation.

Methods

Consecutive patients with documented atypical flutter were included. A high density activation map was generated during the index arrhythmia and subsequently, entrainment maneuvers were performed to delineate the active circuit.

Results

Seventeen patients (82% males, average age 62+-7 years, 59% structural heart disease and 53% with a previous left atrial ablation) underwent 20 procedures. Twenty-one circuits were identified (20 in the left atrium and 1 in the right atrium).  Of all LA circuits, 15 were macroreentrant (8 roof dependent, 4 perimitral and 3 related to a gap after AF ablation. Four out of 5 microreentrant circuits were related to the left atrial appendage and 1 was identified in the septum. Overall, procedural duration and fluoroscopy time was 176 ± 55 minutes and 27 ± 13 minutes, respectively. Roof-dependent ARTs and gap-related ARTs after AF ablation exhibited a significantly longer TCL (359 ± 99 ms and 331 ± 47 ms, respectively, p &lt; 0,05) than perimitral, microreentrant and RA circuits (279 ± 50 ms; 277 ± 36 ms; and 260 ms, respectively). Extensive areas of low voltage (&lt;0.3 mV) were identified in all patients with LA circuits.

Conclusions

The cycle length of complex atrial reentrant tachycardias is apparently related to the location and characteristics of the circuits. This feature can be of help at the time of approaching the mapping and ablation of this tachycardias.

1321From high-density mapping to low-density mapping: an approach to delineate the active circuit in complex atrial reentrant tachycardias

Funding Acknowledgements

NA

OnBehalf

NA

Background

High-density activation maps during complex atrial reentrant tachycardias are challenging to interpret as they include the activation patterns of active and passive circuits. Entrainment mapping provides the identification of the active tachycardia circuit. However, current electroanatomic mapping systems are not capable to color-coded the information obtained from entrainment maneuvers.

Objectives

 We sought to describe a mapping approach for ablation of complex atrial reentrant tachycardias in which high-density activation maps are transformed into low-density activation maps only displaying the active part of the tachycardia circuit.

Methods

We included consecutive patients with atypical atrial flutter. A high-density activation map was acquired during the index tachycardia. Subsequently, entrainment maneuvers were performed to generate a low-density activation map in which only the activation of the atria directly involved in the flutter circuit was displayed.

Results

 Seventeen patients were included 82%  male, mean age was 62 ± 7 years. Structural heart disease was present in 59% and 53% had a prior left atrial ablation procedure. Low-density activation maps were successfully generated from an average of  14 ± 3 entrainment points. Twenty circuits (95%) were identified in the left atrium and 1 (5%) in the right atrium. Ablation guided by low-density mapping successfully terminated all ARTs in 267 ± 353 seconds of radiofrequency application.

Conclusion

Low-density mapping based on entrainment maneuvers provides a precise delineation of the active circuit during complex ARTs and resulted in successful arrhythmia termination. This approach can be easily incorporated into clinical practice.

Extracorporeal cardiopulmonary resuscitation in out-of-hospital cardiac arrest: a registry study

Aims

Out-of-hospital cardiac arrest (OHCA) without return of spontaneous circulation (ROSC) despite conventional resuscitation is common and has poor outcomes. Adding extracorporeal membrane oxygenation (ECMO) to cardiopulmonary resuscitation (extracorporeal-CPR) is increasingly used in an attempt to improve outcomes.

Methods and results

We analysed a prospective registry of 13 191 OHCAs in the Paris region from May 2011 to January 2018. We compared survival at hospital discharge with and without extracorporeal-CPR and identified factors associated with survival in patients given extracorporeal-CPR. Survival was 8% in 525 patients given extracorporeal-CPR and 9% in 12 666 patients given conventional-CPR (P = 0.91). By adjusted multivariate analysis, extracorporeal-CPR was not associated with hospital survival [odds ratio (OR), 1.3; 95% confidence interval (95% CI), 0.8–2.1; P = 0.24]. By conditional logistic regression with matching on a propensity score (including age, sex, occurrence at home, bystander CPR, initial rhythm, collapse-to-CPR time, duration of resuscitation, and ROSC), similar results were found (OR, 0.8; 95% CI, 0.5–1.3; P = 0.41). In the extracorporeal-CPR group, factors associated with hospital survival were initial shockable rhythm (OR, 3.9; 95% CI, 1.5–10.3; P = 0.005), transient ROSC before ECMO (OR, 2.3; 95% CI, 1.1–4.7; P = 0.03), and prehospital ECMO implantation (OR, 2.9; 95% CI, 1.5–5.9; P = 0.002).

Conclusions

In a population-based registry, 4% of OHCAs were treated with extracorporeal-CPR, which was not associated with increased hospital survival. Early ECMO implantation may improve outcomes. The initial rhythm and ROSC may help select patients for extracorporeal-CPR.

Prospective Biomarker Study in Advanced RAS Wild-Type Colorectal Cancer: POSIBA Trial (GEMCAD 10-02)

This articles compares the capacity of several biomarkers (BRAF mutation, PIK3CA mutation/PTEN loss and DP phenotype) to predict 12‐month progression‐free survival and compares it with that of clinical variables

Background.

RAS testing is used to select patients with anti‐epidermal growth factor receptor (EGFR) therapies sensitivity in metastatic colorectal cancer (mCRC). However, other biomarkers such as BRAF, PIK3CA/PTEN, and p‐IGF‐1R+/MMP7+ (double positive [DP] phenotype) have not been prospectively assessed to predict anti‐EGFR resistance.

Materials and Methods.

We designed a multicenter prospective trial (NCT01276379) to evaluate whether the biomarkers BRAF mutation, PIK3CA mutation/PTEN loss, and DP phenotype can improve the prediction for 12‐months progression‐free survival (PFS) over the use of clinical variables exclusively in patients with RAS wild‐type (WT) mCRC treated with standard chemotherapy plus biweekly cetuximab as first‐line therapy. The planned sample size was 170 RAS WT patients to detect a 20% difference in 12‐month PFS based on the analysis of clinical and selected biomarkers (α = .05, β = .2). The discriminatory capacity of the biomarkers was evaluated using receiver operating characteristic curves.

Results.

We included 181 RAS WT patients. The biomarker distribution was as follows: BRAF mutant, 20 patients (11%); PIK3CA mutated/PTEN loss, 98 patients (58%); DP, 23 patients (12.7%). The clinical variables in the clinical score were progression status >0, left‐sided tumor, and resectable liver metastasis as the only metastatic site. The area under the curve (AUC) of the score containing the clinical variables was 0.67 (95% confidence interval [CI], 0.60–0.75). The AUC of the score with clinical variables and BRAF mutational status was 0.68 (0.61–0.75, p = .37). The AUC of the score with clinical variables and PI3KCA mutation/PTEN status was 0.69 (0.61–0.76, p = .32). The AUC of the score with clinical variables and DP phenotype was 0.66 (0.58–0.73, p = .09).

Conclusion.

The addition of BRAF, PIK3CA/PTEN, and DP to a clinical score does not improve the discrimination of 12‐month PFS.

Implications for Practice.

This prospective biomarker design study has important clinical implications because many prospective clinical trials are designed with the hypothesis that BRAF mutation per se and MEK and PIK3CA downstream pathways are critical for colorectal tumor survival. The results lead to the question of whether these pathways should be considered as passengers instead of drivers.