The ubiquitin-modifying enzyme A20 restricts ubiquitination of the kinase RIPK3 and protects cells from necroptosis.

A20 is an anti-inflammatory protein linked to multiple human diseases; however, the mechanisms by which A20 prevents inflammatory disease are incompletely defined. We found that A20-deficient T cells and fibroblasts were susceptible to caspase-independent and kinase RIPK3-dependent necroptosis. Global deficiency in RIPK3 significantly restored the survival of A20-deficient mice. A20-deficient cells exhibited exaggerated formation of RIPK1-RIPK3 complexes. RIPK3 underwent physiological ubiquitination at Lys5 (K5), and this ubiquitination event supported the formation of RIPK1-RIPK3 complexes. Both the ubiquitination of RIPK3 and formation of the RIPK1-RIPK3 complex required the catalytic cysteine of A20's deubiquitinating motif. Our studies link A20 and the ubiquitination of RIPK3 to necroptotic cell death and suggest additional mechanisms by which A20 might prevent inflammatory disease.

Novel time-resolved reporter mouse reveals spatial and transcriptional heterogeneity during alpha cell differentiation.

AIMS/HYPOTHESIS: Glucagon-expressing pancreatic alpha cells have attracted much attention for their plasticity to transdifferentiate into insulin-producing beta cells; however, it remains unclear precisely when, and from where, alpha cells emerge and what regulates alpha cell fate. We therefore explored the spatial and transcriptional heterogeneity of alpha cell differentiation using a novel time-resolved reporter system. METHODS: We established the mouse model, 'Gcg-Timer', in which newly generated alpha cells can be distinguished from more-differentiated cells by their fluorescence. Fluorescence imaging and transcriptome analysis were performed with Gcg-Timer mice during the embryonic and postnatal stages. RESULTS: Fluorescence imaging and flow cytometry demonstrated that green fluorescence-dominant cells were present in Gcg-Timer mice at the embryonic and neonatal stages but not after 1 week of age, suggesting that alpha cell neogenesis occurs during embryogenesis and early neonatal stages under physiological conditions. Transcriptome analysis of Gcg-Timer embryos revealed that the mRNAs related to angiogenesis were enriched in newly generated alpha cells. Histological analysis revealed that some alpha cells arise close to the pancreatic ducts, whereas the others arise away from the ducts and adjacent to the blood vessels. Notably, when the glucagon signal was suppressed by genetic ablation or by chemicals, such as neutralising glucagon antibody, green-dominant cells emerged again in adult mice. CONCLUSIONS/INTERPRETATION: Novel time-resolved analysis with Gcg-Timer reporter mice uncovered spatiotemporal features of alpha cell neogenesis that will enhance our understanding of cellular identity and plasticity within the islets. DATA AVAILABILITY: Raw and processed RNA sequencing data for this study has been deposited in the Gene Expression Omnibus under accession number GSE229090.

Apelin expression is downregulated in T cells in a murine model of chronic colitis.

Apelin (APL), an endogenous ligand for APJ, has been reported to be upregulated in a murine model of acute colitis induced by sodium dextran sulfate, as well as inflammatory bowel diseases (IBD) in humans. However, the mechanisms and functions of APL/APJ axis in the pathogenesis of IBD are unclear. We herein analyzed CD4+ T cells to determine the functions of APL in a murine model of chronic colitis induced in Rag deficient mice (Rag-/-). In colonic tissues of wild-type mice (WT), we found that APL was expressed especially in the lamina propria lymphocytes, where CD4+ T cells are dominant, rather than the epithelial cells. Unexpectedly, the APL expression was rather downregulated in the colonic tissue of the chronic colitis group compared to the control groups (Rag-/- before colitis induction and WT). The APL expression was downregulated when naïve T cells were differentiated into effecter T cells. A lack of APL resulted in decreased naïve T cells and increased effecter T cells in secondary lymphoid organs. A synthetic APL peptide, [Pyr1]-APL-13, increased IL-10 and decreased IFN-γ productions by effecter T cells. Administration of [Pyr1]-APL-13 improved survival rate in association with lessened colitis severity and decreased pro-inflammatory cytokine production. This is the first report showing immunological function of APL specifically on T cells, and these results indicate that APL/APJ axis may be a novel therapeutic target for IBD.

Expression of A20 by dendritic cells preserves immune homeostasis and prevents colitis and spondyloarthritis.

Dendritic cells (DCs), which are known to support immune activation during infection, may also regulate immune homeostasis in resting animals. Here we show that mice lacking the ubiquitin-editing molecule A20 specifically in DCs spontaneously showed DC activation and population expansion of activated T cells. Analysis of DC-specific epistasis in compound mice lacking both A20 and the signaling adaptor MyD88 specifically in DCs showed that A20 restricted both MyD88-independent signals, which drive activation of DCs and T cells, and MyD88-dependent signals, which drive population expansion of T cells. In addition, mice lacking A20 specifically in DCs spontaneously developed lymphocyte-dependent colitis, seronegative ankylosing arthritis and enthesitis, conditions stereotypical of human inflammatory bowel disease (IBD). Our findings indicate that DCs need A20 to preserve immune quiescence and suggest that A20-dependent DC functions may underlie IBD and IBD-associated arthritides.

Nickel particles are present in Crohn's disease tissue and exacerbate intestinal inflammation in IBD susceptible mice.

Crohn's disease is an inflammatory disease of the gut caused by a complex interplay among genetic, microbial, and environmental factors. The intestinal tract is constantly exposed to metals and other trace elements ingested as food. Synchrotron radiation-induced X-ray fluorescence spectroscopy and X-ray absorption fine structure analysis revealed the deposition of nickel particles within Crohn's disease tissue specimens. After nickel particle stimulation, THP-1 cells showed filopodia formation and autophagic vacuoles containing lipid bodies. Nickel particles precipitated colitis in mice bearing mutations of the IBD susceptibility protein A20/TNFAIP3. Nickel particles also exacerbated dextran sulfate sodium-induced colitis in mice harboring myeloid cell-specific Atg5 deficiency. These findings illustrate that nickel particle ingestion may worsen Crohn's disease by perturbing autophagic processes in the intestine, providing new insights into environmental factors in Crohn's disease pathogenesis.

Zranb1-mutant mice display abnormal colonic mucus production and exacerbation of DSS-induced colitis.

Expression of mucin MUC2, a component of the colonic mucus layer, plays a crucial role in intestinal homeostasis. Here, we describe a new regulator of MUC2 expression, the deubiquitinase ZRANB1 (Trabid). A ZRANB1 mutation changing cysteine to serine in amino acid position 443, affects ubiquitination. To analyze ZRANB1 function in the intestine, we generated Zranb1 C443S mutant knock-in (Zranb1C443S/C443S) mice using the CRISPR/Cas9 system. Zranb1C443S/C443S mice exhibited decreased mRNA expression and MUC2 production. Colonic organoids from Zranb1C443S/C443S mice displayed decreased Muc2 mRNA expression following differentiation into goblet cells. Finally, we analyzed dextran sulfate sodium-induced colitis to understand ZRANB1's role in intestinal inflammation. Zranb1C443S/C443S mice with colitis exhibited significant weight loss, reduced colon length, and worsening clinical and pathological scores, indicating that ZRANB1 contributes to intestinal homeostasis. Together, these results suggest that ZRANB1 regulates MUC2 expression and intestinal inflammation, which may help elucidating the pathogenesis of inflammatory bowel disease and developing new therapeutics targeting ZRANB1.

Nickel ions attenuate autophagy flux and induce transglutaminase 2 (TG2) mediated post-translational modification of SQSTM1/p62.

Nickel, the most frequent contact allergy cause, is widely used for various metallic materials and medical devices. Autophagy is an intracellular protein degradation system and contributes to metal recycling. However, it is unclear the functions of nickel in autophagy. We here demonstrated that NiCl2 induced microtubule-associated protein 1 light chain 3 (LC3)-II and LC3 puncta, markers of autophagosomes. Bafilomycin A1 (BafA1) treatment did not enhance LC3 puncta under NiCl2 stimulation, suggesting that NiCl2 did not induce autophagic flux. In addition, NiCl2 promotes the accumulation of SQSTM1/p62 and increased SQSTM1/p62 colocalization with lysosomal-associated membrane protein 1 (LAMP1). These data indicated that NiCl2 attenuates autophagic flux. Interestingly, NiCl2 induced the expression of the high-molecular-weight (MW) form of SQSTM1/p62. Inhibition of NiCl2-induced reactive oxygen species (ROS) reduced the high-MW SQSTM1/p62. We also showed that NiCl2-induced ROS activate transglutaminase (TG) activity. We found that transglutaminase 2 (TG2) inhibition reduced high-MW SQSTM1/p62 and SQSTM1/p62 puncta under NiCl2 stimulation, indicating that TG2 regulates SQSTM1/p62 protein homeostasis under NiCl2 stimulation. Our study demonstrated that nickel ion regulates autophagy flux and TG2 restricted nickel-dependent proteostasis.

CEACAM1 specifically suppresses B cell receptor signaling-mediated activation.

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) expressed in T cells may regulate immune responses in the gut. In addition to T cells, B cells are also an important population in the gut-associated lymphoid tissues that orchestrate mucosal homeostasis. However, the role of CEACAM1 in B cells has not been elucidated. We herein analyzed mature B cells to determine the functions of CEACAM1. Flow cytometry revealed high expression of CEACAM1 on B cells in secondary lymphoid tissues. Cytokine production induced by activation of B cell receptor (BCR) signaling was suppressed by CEACAM1 signaling in contrast to that associated with either Toll-like receptor 4 or CD40 signaling. Confocal microscopy revealed co-localization of CEACAM1 and BCR when activated with anti-Igµ F(ab')2 fragment. Overexpression of CEACAM1 in a murine B cell line, A20, resulted in reduced expressions of activation surface markers with decreased Ca2+ influx after BCR signal activation. Overexpression of CEACAM1 suppressed BCR signal cascade in A20 cells in association with decreased spontaneous proliferation. Our results suggest that CEACAM1 can regulate BCR-mediated mature B cell activation in lymphoid tissues. Therefore, further studies of this molecule may lead to greater insights into the mechanisms of immune responses within peripheral tissues and the potential treatment of inflammatory diseases.

Functional analysis of isoflavones using patient-derived human colonic organoids.

Inflammatory bowel disease (IBD) comprises two major subtypes, ulcerative colitis (UC) and Crohn's disease, which are multifactorial diseases that may develop due to genetic susceptibility, dysbiosis, or environmental factors. Environmental triggers of IBD include food-borne factors, and a previous nationwide survey in Japan identified pre-illness consumption of isoflavones as a risk factor for UC. However, the precise mechanisms involved in the detrimental effects of isoflavones on the intestinal mucosa remain unclear. The present study employed human colonic organoids (hCOs) to investigate the functional effect of two representative isoflavones, genistein and daidzein, on human colonic epithelial cells. The addition of genistein to organoid reformation assays significantly decreased the number and size of reformed hCOs compared with control and daidzein treatment, indicating an inhibitory effect of genistein on colonic cell/progenitor cell function. Evaluation of the phosphorylation status of 49 different receptor tyrosine kinases showed that genistein selectively inhibited phosphorylation of epidermal growth factor receptor (EGFR) and hepatocyte growth factor receptor (HGFR). We established a two-dimensional wound-repair model using hCOs and showed that genistein significantly delayed the overall wound-repair response. Our results collectively show that genistein may exert its detrimental effects on the intestinal mucosa via negative regulation of stem/progenitor cell function, possibly leading to sustained mucosal injury and the development of UC.

Impact of Chronic Kidney Disease on In-Hospital and 3-Year Clinical Outcomes in Patients With Acute Myocardial Infarction Treated by Contemporary Percutaneous Coronary Intervention and Optimal Medical Therapy　- Insights From the J-MINUET Study.

BACKGROUND: The impact of chronic kidney disease (CKD) on long-term outcomes following acute myocardial infarction (AMI) in the era of modern primary PCI with optimal medical therapy is still in debate.Methods and Results:A total of 3,281 patients with AMI were enrolled in the J-MINUET registry, with primary PCI of 93.1% in STEMI. CKD stage on admission was classified into: no CKD (eGFR ≥60 mL/min/1.73 m2); moderate CKD (60>eGFR≥30 mL/min/1.73 m2); and severe CKD (eGFR <30 mL/min/1.73 m2). While the primary endpoint was all-cause mortality, the secondary endpoint was major adverse cardiac events (MACE), defined as a composite of all-cause death, cardiac failure, myocardial infarction (MI) and stroke. Of the 3,281 patients, 1,878 had no CKD, 1,073 had moderate CKD and 330 had severe CKD. Pre-person-days age- and sex-adjusted in-hospital mortality significantly increased from 0.014% in no CKD through 0.042% in moderate CKD to 0.084% in severe CKD (P<0.0001). Three-year mortality and MACE significantly deteriorated from 5.09% and 15.8% in no CKD through 16.3% and 38.2% in moderate CKD to 36.7% and 57.9% in severe CKD, respectively (P<0.0001). C-index significantly increased from the basic model of 0.815 (0.788-0.841) to 0.831 (0.806-0.857), as well as 0.731 (0.708-0.755) to 0.740 (0.717-0.764) when adding CKD stage to the basic model in predicting 3-year mortality (P=0.013; net reclassification improvement [NRI] 0.486, P<0.0001) and MACE (P=0.046; NRI 0.331, P<0.0001) respectively. CONCLUSIONS: CKD remains a useful predictor of in-hospital and 3-year mortality as well as MACE after AMI in the modern PCI and optimal medical therapy era.

Validation of the atherothrombotic risk score for secondary prevention in patients with acute myocardial infarction: the J-MINUET study.

Thrombolysis in Myocardial Infarction Risk Score for Secondary Prevention (TRS2°P) is a contemporary risk scoring system for secondary prevention based on nine clinical factors. However, this scoring system has not been validated in other populations. The aim of this study was to validate the TRS2°P in patients with acute myocardial infarction (AMI) treated with primary percutaneous coronary intervention (PCI) in a nationwide registry cohort. Among 3283 consecutive patients with AMI enrolled in the Japanese registry of acute Myocardial INfarction diagnosed by Universal dEfiniTion (J-MINUET), a total of 2611 patients who underwent primary PCI were included in this study. The performance of the TRS2°P to predict major adverse cardiovascular events (MACE) composed of all-cause death, non-fatal MI, and non-fatal stroke up to 3 years in the present cohort was evaluated. The TRS2°P had modest discriminative performance in this J-MINUET cohort with a c-statistic of 0.63, similar to that in the derived cohort (TRA2°P-TIMI50, c-statistic 0.67). A strong graded relationship between the TRS2°P and 3-year cardiovascular event rates was also observed in the J-MINUET cohort. Age ≥ 75 years, Killip ≥ 2, prior stroke, peripheral artery disease, anemia, and non-ST-elevation myocardial infarction were identified as independent factors for the incidence of MACE. The TRS2°P modestly predicted secondary cardiovascular events among patients with AMI treated by primary PCI in a nationwide cohort of Japan. Further studies are needed to develop a novel risk score better predicting secondary cardiovascular events.

Long-Term Clinical Impact of Cardiogenic Shock and Heart Failure on Admission for Acute Myocardial Infarction.

Long-term clinical outcomes among patients with cardiogenic shock (CS) and heart failure (HF) who survive the early phase of acute myocardial infarction (AMI) remain uncertain. We investigated 3283 consecutive patients with AMI, selected from a prospective, nation-wide multicenter registry (J-MINUET) database comprising 28 institutions in Japan between July 2012 and March 2014. The 3263 eligible patients were divided into the following three groups: CS-/HF- group (n = 2467, 75.6%); CS-/HF+ group (n = 479, 14.7%); and CS+ group (n = 317, 9.7%). The thirty-day mortality rate in CS+ patients was 32.8%, significantly higher than in CS- patients. Among CS+ patients, multivariate logistic regression analysis identified statin use before admission (Odds ratio (OR) 0.32, 95% confidence interval (CI) 0.14-0.66, P = 0.002), renal deficiency (OR 8.72, 95%CI 2.81-38.67, P < 0.0001) and final thrombolysis in myocardial infarction flow grade (OR 0.42, 95%CI 0.18-0.99, P = 0.046) were associated with 30-day mortality. Landmark Kaplan-Meier analysis showed that mortality rates after 30 days were comparable between CS+ and CS-/HF+ groups but were lower in the CS-/HF- group. Multivariate Cox hazard analysis also showed that hazard risk of mortality after 30 days was comparable between the CS+ and CS-/HF+ groups (Hazard ratio (HR) 1.03, 95%CI 0.63-1.68, P = 0.90), and significantly lower in the CS-/HF- group (HR 0.44, 95%CI 0.32-059, P < 0.0001). In conclusion, AMI patients with CS who survived 30 days experienced worse long-term outcomes compared with those without CS up to 3 years. Attention is required for patients who show HF on admission without CS to improve long-term AMI outcomes.

High-fat diet-derived free fatty acids impair the intestinal immune system and increase sensitivity to intestinal epithelial damage.

In Japan and other Asian countries, increased fat uptake induced by a westernized diet is thought to be associated with an increased incidence of inflammatory bowel disease, colorectal cancer and food allergies; however, the mechanism for this remains unclear. High-fat diet (HFD)-fed mice are common animal models used to examine the effect of fat intake in vivo. HFDs are reported to exacerbate DSS-induced colitis and intestinal tumorigenesis, but the effect of HFDs on the intestines before disease induction is often overlooked. We found that the intestinal and gut-associated lymphoid tissue (GALT) morphology of HFD-fed mice differed from that of standard diet (SD)-fed mice. To clarify the mechanism by which fat intake increases intestinal diseases, we analyzed the morphological and immunological aspects of the intestines of HFD-fed mice as well as the molecular mechanisms and physiology. Feeding an HFD for 3 weeks induced atrophy of the small intestine, colon and GALT and reduced the number of small intestinal intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs). Feeding an HFD for only one day reduced the number of small intestinal (SI)-IELs and SI-LPLs. The effect of feeding a 3-week HFD continued for 2 weeks after returning to the SD. The effect of the HFD on the intestinal immune system was independent of the gut microbes. We hypothesized that the cytotoxicity of the abundant HFD-derived free fatty acids in the intestinal lumen impairs the intestinal immune system. Both saturated and unsaturated free fatty acids were toxic to intestinal T-cells in vitro. Orally administering free fatty acids reduced the number of SI-IELs and LPLs. Using a lipase inhibitor to reduce the luminal free fatty acids attenuated the HFD-induced changes in the intestinal immune system, while using a statin to reduce the serum free fatty acids did not. Thus, HFD-induced free fatty acids damaged the intestines; this effect was termed "intestinal lipotoxicity". Because sustained reduction of SI-LPLs after HFD feeding exacerbated indomethacin-induced small intestinal damage, lipotoxicity to the human intestines incurred by consuming a westernized diet in Japan may increase intestinal diseases such as IBD, colorectal cancer or food allergies.

CD8αα+ T cells show amoeboid shape and frequent morphological change in vitro, and localize to small intestinal intraepithelial region in vivo.

Intraepithelial lymphocytes (IELs) are very unique in the intestinal immune system. They include γδT cells and CD4-CD8-TCRαß+T cells (double negative: DNT), both of which are specific for the intestine, in addition to CD4+ and CD8+ T cells. IELs exist within the monolayer of the intestinal epithelial cells and dynamically move between lamina propria (LP) and intraepithelial (IE) region. The localization and movement patterns of IEL subsets and the regulatory factors have been unknown. Here, we developed a novel in vitro live imaging system and quantified the motility and morphological changes among subsets of IELs. We identified CD8αα as the key regulatory factor. IELs, especially γδ and DNT cells, showed amoeboid shape and frequent morphological change, while most T cells in MLN or SP showed round shape in vitro. TCR signal, IL-15, gut microbes, CCL25, and integrin αEß7 expression were non-essential for IEL movement in vitro. CD8αα+ cells showed higher motility and larger morphological changes than CD8αα- cells. Adoptive transferred CD8αα+CD4-IELs localized to IE region of recipient NSG mice, while CD8αα-CD4-IELs localized to the LP. Our results showed that the CD8αα/TL signal is essential for the localization of IELs to IE region in vivo. CD8αα/TL may be an effective target to increase the number of IELs, which protects against intestinal infection, allergy, tumorigenesis or inflammation.

TGF-ß promotes fetal gene expression and cell migration velocity in a wound repair model of untransformed intestinal epithelial cells.

The early-phase wound repair response of the intestinal epithelium is characterized by rapid and organized cell migration. This response is regulated by several humoral factors, including TGF-ß. However, due to a lack of appropriate models, the precise response of untransformed intestinal epithelial cells (IECs) to those factors is unclear. In this study, we established an in vitro wound repair model of untransformed IECs, based on native type-I collagen. In our system, IECs formed a uniform monolayer in a two-chamber culture insert and displayed a stable wound repair response. Gene expression analysis revealed significant induction of Apoa1, Apoa4, and Wnt4 during the collagen-guided wound repair response. The wound repair response was enhanced significantly by the addition of TGF-ß. Surprisingly, addition of TGF-ß induced a set of genes, including Slc28a2, Tubb2a, and Cpe, that were expressed preferentially in fetal IECs. Moreover, TGF-ß significantly increased the peak velocity of migrating IECs and, conversely, reduced the time required to reach the peak velocity, as confirmed by the motion vector prediction (MVP) method. Our current in vitro system could be employed to assess other humoral factors involved in IEC migration and could contribute to a deeper understanding of the wound repair potentials of untransformed IECs.

Prognostic Impact of B-Type Natriuretic Peptide on Long-Term Clinical Outcomes in Patients with Non-ST-Segment Elevation Acute Myocardial Infarction Without Creatine Kinase Elevation.

Although B-type natriuretic peptide (BNP) has gradually gained recognition as an indicator in risk stratification for patients with acute myocardial infarction (AMI), the prognostic impact on long-term clinical outcomes in patients with non-ST-segment elevation acute myocardial infarction (NSTEMI) without creatine kinase (CK) elevation remains unclear.This prospective multicenter study assessed 3,283 consecutive patients with AMI admitted to 28 institutions in Japan between 2012 and 2014. We analyzed 218 patients with NSTEMI without CK elevation (NSTEMI-CK) for whom BNP was available. In the NSTEMI-CK group, patients were assigned to high- and low-BNP groups according to BNP values (cut-off BNP, 100 pg/mL). The primary endpoint was defined as a composite of all-cause death, non-fatal myocardial infarction, non-fatal stroke, cardiac failure, and urgent revascularization for unstable angina up to 3 years. Primary endpoints were observed in 60 (33.3%) events among patients with NSTEMI-CK. Kaplan-Meier analysis revealed a significantly higher event rate for primary endpoints among patients with high BNP (log-rank P < 0.001). After adjusting for covariates, a higher BNP level was significantly associated with long-term clinical outcomes in NSTEMI-CK (adjusted hazard ratio, 4.86; 95% confidence interval, 2.18-12.44; P < 0.001).The BNP concentration is associated with adverse long-term clinical outcomes among patients with NSTEMI-CK who are considered low risk. Careful clinical management may be warranted for secondary prevention in patients with NSTEMI-CK with high BNP levels.

Admission During Off-Hours Does Not Affect Long-Term Clinical Outcomes of Japanese Patients with Acute Myocardial Infarction.

Discordant results have been reported on outcomes of acute myocardial infarction (AMI) patients who present during off-hours.We investigated 3283 consecutive patients with AMI who were selected from the prospective, nationwide, multicenter registry (J-MINUET) database comprising 28 institutions in Japan between July 2012 and March 2014 to determine the current impact of off-hours presentation (defined as weekends, holidays, and weekdays from 8:01 PM to 7:59 AM) at hospitals on long-term clinical outcomes. The primary endpoint was a composite of all-cause death, non-fatal MI, non-fatal stroke, cardiac failure, and urgent revascularization for unstable angina for up to 3 years from the index event.During off-hours, 52% of patients presented. Primary percutaneous coronary intervention was performed in 85% of patients, and the door-to-balloon time was comparable between off-hours and regular hours (74, interquartile range [IQR] 52 to 113 versus 75, IQR 52 to 126 minutes, P = 0.34). Rate of overall primary endpoint overall did not overall significantly differ (25.3% versus 23.5%, log-rank P = 0.26), in patients with ST-elevation myocardial infarction (STEMI) (log-rank P = 0.93) and in patients with non-ST-elevation myocardial infarction (NSTEMI) (log-rank P = 0.14). Multivariate Cox regression analysis showed that off-hours presentation was not significantly associated with long-term clinical events in all cohorts.The impact of presentation during off-hours or regular hours on the long-term clinical outcomes of Japanese patients with AMI is comparable in contemporary practice.

Uninterrupted vs. interrupted periprocedural direct oral anticoagulants for catheter ablation of atrial fibrillation: a prospective randomized single-centre study on post-ablation thrombo-embolic and haemorrhagic events.

AIMS: This prospective, randomized, single-centre study aimed to directly compare the safety and efficacy of uninterrupted and interrupted periprocedural anticoagulation protocols with direct oral anticoagulants (DOACs) in patients undergoing catheter ablation of non-valvular atrial fibrillation (NVAF). METHODS AND RESULTS: We randomly assigned 846 NVAF patients receiving DOACs prior to ablation to uninterruption (n = 422) or interruption (n = 424) of the DOACs on the day of the procedure. The primary endpoint was a composite of symptomatic thromboembolisms and major bleeding events within 30 days after the ablation. Secondary endpoints included symptomatic and silent thromboembolisms and major and minor bleeding events. The primary endpoint occurred in 0.7% of the uninterrupted DOAC group [1 transient ischaemic attack (TIA) and 2 major bleeding events] and 1.2% of the interrupted DOAC group (1 TIA and 4 major bleeding events) (P = 0.480). The incidence of major and minor bleeding was comparable between the two groups (0.5% vs. 0.9%, P = 0.345; 5.9% vs. 5.4%, P = 0.753). Silent cerebral ischaemic lesions (SCILs) were observed in 138 (20.9%) of the 661 patients undergoing post-ablation magnetic resonance (MR) imaging. The uninterrupted and interrupted DOAC groups revealed a similar incidence of SCILs (19.8% vs. 22.0%, P = 0.484) and percentage of SCILs with disappearance on follow-up MR imaging (77.8% vs. 82.1%, P = 0.428). CONCLUSION: Both the uninterrupted and interrupted DOAC protocols revealed a low risk of symptomatic thromboembolisms and major bleeding events and similar incidence of SCILs and minor bleeding events and may be feasible for periprocedural anticoagulation in NVAF patients undergoing catheter ablation.

Relationship Between Exercise Oscillatory Ventilation Loop and Prognosis of Heart Failure.

BACKGROUND: The cardiopulmonary exercise test (CPX) is a tool for evaluating disease severity and limitations in activities of daily living in patients with cardiac disorders. However, few studies have evaluated the association between exercise oscillatory ventilation (EOV) severity and prognosis in heart failure (HF) patients with EOV. EOV severity can be evaluated by detecting endtidal CO2pressure (PETCO2, an indicator of the arterial partial pressure of CO2(PaCO2)) and minute ventilation, which is a reflection of the respiratory response to elevated CO2. We hypothesized that the magnitude of EOV severity can predict the severity and prognosis of cardiac disorders and aimed to validate this hypothesis.Methods and Results:In total, 2,043 patients who underwent symptom-limited maximal CPX between 2010 and 2016 were evaluated. We enrolled 70 patients who had HF with reduced ejection fraction (HFrEF) and EOV. The endpoint was cardiovascular death. During a median follow-up of 4.3 years, 34 participants died (48%). Those who died showed significantly larger EOV loop size and lower hemoglobin (Hb) levels than those who survived (17.3±7.0 cm2vs. 12.8±6.1 cm2, P<0.001; 12.2±1.2 g/dL vs. 13.2±2.9 g/dL, P=0.004). Cox regression analyses revealed Hb levels and EOV loop size as independent predictors of cardiovascular death in HFrEF patients with EOV. CONCLUSIONS: EOV loop size was associated with cardiovascular death of HFrEF patients with EOV.