Impact of obstructive sleep apnoea on long-term atrial fibrillation-free survival after catheter ablation

Introduction

Early rhythm-control therapy of atrial fibrillation (AF) (including catheter ablation) has been established as significantly lowering risk of adverse cardiovascular outcomes and improving overall survival and quality of life. Obstructive sleep apnoea (OSA) is a common but often overlooked comorbidity in patients with AF that may lead to difficulties in maintaining sinus rhythm. Data on the impacts of its treatment on recurrence remain conflicting.

Objective

To determine the prevalence of OSA in a population of AF patients submitted to catheter ablation and its impact on recurrence after a successful procedure.

Methods

Retrospective study of patients with AF consecutively submitted to catheter ablation in a tertiary centre between January 2017 and December 2020. The main outcome was AF recurrence after ablation. Sociodemographic variables and clinical data were retrieved for each patient, including type of AF, comorbidities, screening and diagnosis of OSA, treatment of OSA prior to ablation, time from ablation to recurrence of AF, method of ablation (radiofrequency or cryo). Statistical comparison between patients with and without OSA was made, including survival curves and Cox regression to determine time to recurrence and adjust for confounding variables.

Results

A total of 189 patients were included with a mean age of 63.49±11.09 years. Mean follow-up time after ablation was 2.76±1.56 years. Patients who recurred after ablation had undergone more electrical cardioversions prior to the procedure (1.640±1.583 vs 0.800±0.966, p 0.002), had more persistent AF (p 0.036) and had more OSA (32.7% vs 15.7%, p=0.011). There were no differences regarding age, gender, body-mass index, history of hypertension, diabetes, chronic kidney disease or heart failure, method of ablation and diagnosis of OSA prior to ablation.

Forty-nine patients (18.7%) had OSA, with only 16 (32.7%) having been diagnosed before ablation. OSA was screened in only 60 cases (31.7%), mostly due to symptoms (76.1%) and not per protocol. Patients with OSA had earlier recurrence of AF after ablation (p Log-rank 0.012) with a hazard two times greater of recurrence, even after adjusting for confounding (p 0.026; hazard-ratio 2.025; confidence interval 95% 1.086–3.775). One year recurrence rate was 31% in patients with OSA (vs 15%). Regarding patients under treatment for OSA prior to ablation, there was no difference in survival (p Log-rank 0.859).

Conclusion

In real-world practice, OSA is still a largely underinvestigated condition that significantly impairs AF control and contributes to worse cardiovascular outcomes. Recurrence was 2 times higher in patients with OSA. No impact of treatment in time to recurrence was found. Efforts must be made to increase screening of this condition in order to improve outcomes. Further studies are needed to clarify the benefits of OSA treatment in AF recurrence.

Funding Acknowledgement

Type of funding sources: None.

Endometrial uNK cell counts do not predict successful implantation in an IVF population

STUDY QUESTION

Are uterine natural killer (uNK) cell numbers and their distribution relative to endometrial arterioles altered in women with recurrent implantation failure (RIF) compared to women with embryo implantation success (IS)?

SUMMARY ANSWER

uNK cell numbers and their distribution relative to endometrial arterioles are not significantly different in women with RIF compared to women in whom embryo implantation occurs successfully following IVF.

WHAT IS ALREADY KNOWN

uNK cells are regulators of decidual angiogenesis and spiral arteriole remodelling during early pregnancy. Although some studies have shown that uNK cell numbers may be altered in women with RIF, the methods used to measure uNK cell numbers have proven inconsistent, making reproduction of these results difficult. It is unclear, therefore, whether the results reported so far are reproducible. Moreover, it is not known how uNK cell numbers may impact IVF outcomes. Despite the lack of conclusive evidence, uNK cell numbers are often evaluated as a prognostic criterion in women undergoing assisted reproductive procedures.

STUDY DESIGN, SIZE, DURATION

Endometrial pipelle biopsies were collected 6-8 days post-LH surge in natural cycles from women with RIF (n = 14), women with IS (n = 11) and women with potential RIF at the time of the study (PRIF; n = 9) from 2013 to 2015.

PARTICIPANTS/MATERIALS, SETTING, METHODS

uNK cells (i.e. CD56+ and/or CD16+ phenotypes) and their distribution relative to endometrial arterioles were investigated by standard immunohistochemistry protocols and quantified using Aperio ScanScopeXT images digitized by ImageJ and deconvoluted into binary images for single cell quantification using a Gaussian Blur and Yen algorithm.

MAIN RESULTS AND THE ROLE OF CHANCE

There was no significant difference in the cell density of CD56+ or CD16+ uNK cells in women with RIF compared to women with IS or PRIF. There was a higher proportion of uNK cells in the distal regions compared to the regions closest to the arterioles in all patient groups. Further, we identified a significant reduction in uNK cell density in women who had a previous pregnancy compared to those who had not, regardless of their current implantation status.

LARGE SCALE DATA

Not applicable.

LIMITATIONS, REASONS FOR CAUTION

Spiral arterioles could not always be accurately identified by digital image analysis; therefore, all endometrial arterioles were selected and analysed. Patient numbers for the study were low. However, as the clinical phenotypes of each patient were well defined, and endometrial dating was accurately determined by three independent pathologists, differences between patient groups with respect to the uNK numbers and distribution should have been measurable if uNK cell counts were to be useful as a prognostic marker of RIF.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings demonstrate that CD56+ and CD16+ uNK cell numbers are not significantly different in women with RIF in a typical cohort of women undergoing IVF. Further, prior pregnancy was associated with a significantly reduced number of uNK cells in both the RIF and IS patient groups, suggestive of a long-term pregnancy induced suppression of uNK cells. Combined, these findings do not support the clinical value of using uNK cell numbers as a prognostic indicator of implantation success with IVF treatment.

STUDY FUNDING/COMPETING INTEREST(S)

Funding for this work was provided by Royal Women's Hospital Foundation. P.P. was supported by an NHMRC Early Career Fellowship [TF 11/14] and W.T.T. was supported by an NHMRC Postgraduate Scholarship [1055814]. The authors do not have any competing interests with this study.

Generation of immortalized human endometrial stromal cell lines with different endometriosis risk genotypes

Endometriotic lesions are composed in part of endometrial-like stromal cells, however, there is a shortage of immortalized human endometrial stromal cultures available for research. As genetic factors play a role in endometriosis risk, it is important that genotype is also incorporated into analysis of pathological mechanisms. Human telomerase reverse transcriptase (hTERT) immortalization (using Lenti-hTERT-green fluorescent protein virus) took place following genotype selection; 13 patients homozygous for either the risk or non-risk 'other' allele for one or more important endometriosis risk single nucleotide polymorphism on chromosome 1p36.12 (rs3820282, rs56318008, rs55938609, rs12037376, rs7521902 or rs12061255). Short tandem repeat DNA profiling validated that donor tissue matched that of the immortalized cell lines and confirmed that cultures were genetically novel. Expression of morphological markers (vimentin and cytokeratin) and key genes of interest (telomerase, estrogen and progesterone receptors and LINC00339) were examined and functional assays for cell proliferation, steroid hormone and inflammatory responses were performed for 7/13 cultures. All endometrial stromal cell lines maintained their fibroblast-like morphology (vimentin-positive) and homozygous endometriosis-risk genotype following introduction of hTERT. Furthermore, the new stromal cultures demonstrated positive and diverse responses to hormones (proliferation and decidualisation changes) and inflammation (dose-dependent response), while maintaining hormone receptor expression. In conclusion, we successfully developed a range of human endometrial stromal cell lines that carry important endometriosis-risk alleles. The wider implications of this approach go beyond advancing endometriosis research; these cell lines will be valuable tools for multiple endometrial pathologies offering a level of genetic and phenotypic diversity not previously available.

Recent and emerging reproductive biology research in Australia and New Zealand: highlights from the Society for Reproductive Biology Annual Meeting, 2017

Research in reproductive science is essential to promote new developments in reproductive health and medicine, agriculture and conservation. The Society for Reproductive Biology (SRB) 2017 conference held in Perth (WA, Australia) provided a valuable update on current research programs in Australia and New Zealand. This conference review delivers a dedicated summary of significant questions, emerging concepts and innovative technologies presented in the symposia. This research demonstrates significant advances in the identification of precursors for a healthy pregnancy, birth and child, and discusses how these factors can influence disease risk. A key theme included preconception parental health and its effect on gametogenesis, embryo and fetal development and placental function. In addition, the perturbation of key developmental checkpoints was shown to contribute to a variety of pathological states that have the capacity to affect health and fertility. Importantly, the symposia discussed in this review emphasised the role of reproductive biology as a conduit for understanding the transmission of non-communicable diseases, such as metabolic disorders and cancers. The research presented at SRB 2017 has revealed key findings that have the prospect to change not only the fertility of the present generation, but also the health and reproductive capacity of future generations.

Eosinophil-Associated Gene Pathways but not Eosinophil Numbers are Differentially Regulated between Synchrotron Microbeam Radiation Treatment and Synchrotron Broad-Beam Treatment by 48 Hours Postirradiation

Synchrotron microbeam radiation treatment (MRT) is a preclinical radiotherapy technique with considerable clinical promise, although some of the underlying radiobiology of MRT is still not well understood. In recently reported studies, it has been suggested that MRT elicits a different tumor immune profile compared to broad-beam treatment (BB). The aim of this study was to investigate the effects of synchrotron MRT and BB on eosinophil-associated gene pathways and eosinophil numbers within and around the tumor in the acute stage, 48 h postirradiation. Balb/C mice were inoculated with EMT6.5 mouse mammary tumors and irradiated with microbeam radiation (112 and 560 Gy) and broad-beam radiation (5 and 9 Gy) at equivalent doses determined from a previous in vitro study. After tumors were collected 24 and 48 h postirradiation, RNA was extracted and quantitative PCR performed to assess eosinophil-associated gene expression. Immunohistochemistry was performed to detect two known markers of eosinophils: eosinophil-associated ribonucleases (EARs) and eosinophil major basic protein (MBP). We identified five genes associated with eosinophil function and recruitment (Ear11, Ccl24, Ccl6, Ccl9 and Ccl11) and all of them, except Ccl11, were differentially regulated in synchrotron microbeam-irradiated tumors compared to broad-beam-irradiated tumors. However, immunohistochemical localization demonstrated no significant differences in the number of EAR- and MBP-positive eosinophils infiltrating the primary tumor after MRT compared to BB. In conclusion, our work demonstrates that the effects of MRT on eosinophil-related gene pathways are different from broad-beam radiation treatment at doses previously demonstrated to be equivalent in an in vitro study. However, a comparison of the microenvironments of tumors, which received MRT and BB, 48 h after exposure showed no difference between them with respect to eosinophil accumulation. These findings contribute to our understanding of the role of differential effects of MRT on the tumor immune response.

Analysis of fertility-related soluble mediators in human uterine fluid identifies VEGF as a key regulator of embryo implantation

Embryo implantation requires synchronized dialogue between the receptive endometrium and activated blastocyst via locally produced soluble mediators. During the midsecretory (MS) phase of the menstrual cycle, increased glandular secretion into the uterine lumen contains important mediators that modulate the endometrium and support the conceptus during implantation. This study aimed first to identify the growth factor and cytokine profile of human uterine fluid from fertile women during the midproliferative (MP; nonreceptive) and MS (receptive) phases of the cycle, and from women with unexplained infertility during the MS phase. The second aim was to determine important functions of endometrial secretions for embryo implantation. Analysis of uterine fluid using quantitative Luminex assays revealed the presence of over 30 cytokines and growth factors, of which eight [platelet-derived growth factor-AA, TNF-B, soluble IL-2 receptor-A, Fms-like tyrosine kinase 3 ligand, soluble CD40 ligand, IL-7, interferon-A2, and chemokine (C-X-C motif) ligand 1-3] were previously unknown in human uterine fluid. Comparison of the fertile MP, MS, and infertile MS cohorts revealed vascular endothelial growth factor (VEGF) levels are significantly reduced in uterine fluid during the MS phase in women with unexplained infertility compared with fertile women. Functional studies demonstrated that culturing mouse embryos with either MS-phase uterine fluid from fertile women or recombinant human VEGF significantly enhanced blastocyst outgrowth. Furthermore, treatment of human endometrial epithelial cells with uterine fluid or recombinant human VEGF-A significantly increased endometrial epithelial cell adhesion. Taken together, our data support the concept that endometrial secretions, including VEGF, play important roles during implantation. Identifying the soluble mediators in human uterine fluid and their actions during implantation provides insight into interactions essential for establishing pregnancy, fertility markers, and infertility treatment options.

155. UNDERSTANDING THE CROSSTALK IN THE HUMAN UTERINE CAVITY: ROLES FOR SOLUBLE MEDIATORS DURING EMBRYO IMPLANTATION

Embryo implantation requires synchronized dialogue between a receptive endometrium and an activated blastocyst via locally produced soluble mediators. During the mid-secretory (MS) phase of the menstrual cycle there is increased glandular secretion into the uterine lumen. These secretions contain important mediators that modulate the endometrium and support the conceptus during implantation. Analysis of the composition of uterine fluid across the menstrual cycle and in fertile and infertile women will, therefore, provide new insights into uterine receptivity. We hypothesized that multiplex platform analysis of human uterine lavages would identify soluble mediators important for the establishment of pregnancy in humans. Lavages were collected (by flushing the uterine cavity with 5mL of saline) from fertile and infertile women during the MS phase and from fertile women during the mid-proliferative (MP) phase of the menstrual cycle. Comparison of lavages from the three cohorts was performed using quantitative MilliplexTM Luminex® cytokine/chemokine assays containing 42-analytes. Luminex analysis detected a number of cytokines in uterine fluid, revealing 8 soluble mediators previously unknown in the endometrium and present in human uterine fluid including, PDGF-AA, TNFβ, sIL-2Rα, Flt-3 ligand, sCD40L, IL-7, IFNα2 and GRO. Furthermore comparison of the three cohorts revealed VEGF levels were significantly higher in the fertile (MS) fluid when compared to infertile. Functional studies demonstrated that rhVEGF treatment significantly increased the adhesive properties in cells present at the maternal-fetal interface. These findings suggest VEGF plays a role in regulating embryo implantation. Furthermore identifying the soluble mediators in uterine fluid may provide potential markers of endometrial receptivity, insight into the unique microenvironment essential for pregnancy and a profile of maternal factors that influence the implanting blastocyst.

525. ROLES FOR HUMAN CHORIONIC GONADOTROPHIN IN EMBRYO-ENDOMETRIAL CROSS-TALK DURING BLASTOCYST IMPLANTATION

Emerging evidence suggests an important role for the early embryo product human chorionic gonadotrophin (hCG) in embryo-endometrial interactions critical for successful embryo implantation1. The human endometrium is also a source of hCG, with maximal expression of hCG and its receptor, hCG/LHR, in endometrial epithelial cells during the window of implantation in vivo2,3, and in primary endometrial epithelial cells (EECs)3. Implantation is tightly regulated by growth and regulatory factors produced within the embryo-endometrial microenvironment. We hypothesise that embryo/endometrial-derived hCG mediates the molecular cross talk vital for successful implantation. The main objective of this study was to investigate the effect of hCG on the production of a selected cohort of 42 cytokines and growth factors by EECs. These included those with both known and previously unidentified roles during implantation. The secretory profile of cytokines/growth factors produced by EECs was also analysed. EECs (n=8 cultures) were isolated from biopsies collected from fertile cycling women. Cells were treated without or with recombinant hCG for 48 hr and conditioned media collected for quantitative analysis using LuminexTM multiplex technology. For the first time, a secretory profile of 42 cytokines and growth factors produced by EECs was established, as was the identification of fibroblast growth factor-2 (FGF-2) secretion by human endometrial epithelium. hCG (2 IU/ml) significantly increased the production of a number factors including those with known roles during trophoblast migration and adhesion (CX3CL1; 71±31%, CXCL10; 67±24%, CCL4; 87±12%), in trophoblast differentiation (IL-1α ; 68±31%) and with unidentified roles during implantation (CCL22; 78±40%, GM-CSF; 45±16%, FGF-2; 50±25%; all p<0.05). Upregulation of the known hCG regulated proteins, VEGF and LIF, validated this study. These findings clearly support roles for the embryo/endometrium via hCG in actively contributing to the molecular cross-talk during the early stages of implantation.

107. INTERLEUKIN 11 AND LEUKEMIA INHIBITORY FACTOR REGULATE CYTOKINE NETWORKS IN HUMAN FIRST TRIMESTER PLACENTA

Inadequate trophoblast invasion is thought to be involved in the pathogenesis of preeclampsia (PE). Shallow trophoblast invasion has been implicated to lead to placental hypoxia and a localised overproduction of pro-inflammatory cytokines. Interleukin (IL) 11 and leukemia inhibitory factor (LIF) are IL6-type cytokines produced at the maternal-fetal interphase and regulate human trophoblast migration/invasion, but their mechanisms of action are unknown. We aimed to determine the effect of hypoxia on human placental IL11/LIF secretion and the effect of IL11/LIF on placental cytokine secretion. As an in vitro model we cultured human first trimester placental villous explants (gestation weeks 7-9) in serum free conditions under either 2% (hypoxia) or 20% oxygen (normoxia) (N=8/gp) for 48h. Medium was assayed for IL11/LIF by ELISA. The effect of IL11/LIF (N=6/gp) on placental explant cytokine secretion (26 cytokines) was analysed using a quantitative multiplex immunoassay. Data was expressed as pg/mg wet weight and then as % change vs control (100%). IL11 secretion from explants was decreased by 76±5% (p<0.01) under hypoxia vs normoxia while LIF secretion did not differ significantly. Under normoxia the most highly abundant cytokines were IL6, IL8 and MCP-1 while moderate levels of G-CSF, CX3CL1, IP-10, and PGDF were present in conditioned medium. IL11 increased IL10 secretion while it decreased G-CSF, TNFa, IL1receptor antagonist (Ra), IL6 and PDGF secretion (p<0.05) vs control. Similarly LIF decreased G-CSF, TNFa, IL1Ra and additionally IL8 secretion (p<0.05) vs control. IL6 and VEGF secretion were increased (p<0.05) while MCP-1 was reduced (p<0.05) by hypoxia vs normoxia. This study identified for the first time that IL11 was reduced by hypoxia and identified a profile of cytokines secreted by placenta. IL11 and LIF regulated similar and unique anti-inflammatory cytokines in first trimester placenta. Whether placental IL11 or LIF is altered in women with PE remains to be elucidated however this study suggests mechanisms of action and confirms the importance of IL11/LIF in placentation.

New insights of HLA class I association to Behçet's disease in Portuguese patients

Human leukocyte antigen (HLA)-B*51 is a well-known genetic factor associated with Behçet's disease (BD). To analyse the influence of HLA-B*51 and other HLA class I alleles in BD susceptibility in a Portuguese population and its association with disease severity, we studied 78 BD patients and 208 healthy controls. The patients were classified into two severity groups as described by Gul et al. As expected, a higher frequency of HLA-B*51 was found. The frequency of HLA-Cw*16 alleles was significantly higher in patients. Regarding severity, HLA-B*27 frequency was higher in the severe group compared with controls and with the mild group. Thus, HLA-B*51 and HLA-Cw*16 seem to confer susceptibility to BD in this patients. HLA-B*27 may be important as a prognostic factor.

223. Interleukin-11 inhibits human trophoblast invasion via STAT-3 and not MAPK, indicating a likely role in the decidual restraint of trophoblast invasion during placentation

Successful pregnancy depends on the precise regulation of extravillous trophoblast (EVT) invasion into the uterine decidua, primarily by decidua-derived factors. In humans, during early pregnancy, interleukin (IL)-11 is maximally expressed in the decidua1, with its receptor, IL-11-receptor α (Rα) also identified on invasive EVT in vivo2. While a role for IL-11 in EVT migration has been established2, whether it also plays a role in regulating EVT invasion is unknown. We investigated whether IL-11 influences human EVT invasion and the signalling pathways and underlying mechanisms involved using the HTR-8/SVneo immortalised EVT cell-line and primary EVT as models for EVT. The effect of IL-11 on tyrosine phosphorylation (p) of signal transducer and activator of transcription (STAT)-3 was determined by Western Blot. EVT invasion was assessed using in vitro Matrigel invasion assays. To elucidate the mechanisms by which IL-11 may influence EVT invasion, matrix metalloproteinase (MMP) and urokinase plasminogen activator (uPA) activity were assessed by gelatin and plasminogen zymography / uPA activity assay respectively. Tissue inhibitor of MMPs (TIMPs)-1 and –2, plasminogen activator inhibitor (PAI)-1 and –2 and uPA receptor (uPAR) were assessed by ELISA whereas TIMP-3 was assessed by Western Blot. EVT adhesive properties and integrin expression were assessed by in vitro adhesion assays. IL-11 (100 ng/mL) significantly inhibited invasion of EVT cells by 40–60% (P < 0.001). This effect was abolished by inhibitors of STAT-3 but not of mitogen-activated protein kinase pathways. IL-11 (100 ng/mL) had no effect on MMP-2 and –9, TIMP 1–3, uPA, uPAR, PAI-1 and –2 in EVT conditioned media and / or cell lysates. IL-11 (100 ng/mL) also did not regulate EVT cell adhesion or integrin expression. These data demonstrate that IL-11 inhibits human EVT invasion via STAT-3 indicating an important role for IL-11 in the decidual restraint of EVT invasion during normal pregnancy. (1) Dimitriadis et al. (2003) Reprod Biol Endocrinol. 1, 34–38 (2) Paiva et al. (2007) Endocrinol. 148, 5566–72

249.Activin A upregulates endometrial metalloproteases: potential mechanisms for promotion of decidualisation and implantation

Activin and inhibin subunits are co-expressed by human endometrial epithelial and decidualised stromal cells. Activin A is a potent stimulator of decidualisation in vitro, but the mechanisms are unknown. Matrix metalloproteases (MMPs) are known to be important during decidualisation, as administration of a broad spectrum MMP inhibitor in the rat results in reduced decidualisation. Transforming Growth Factor(TGF)-βs are closely related to activins and inhibit MMP production in endometrial epithelial cells. We hypothesised that activins regulate MMP production during decidualisation and/or trophoblast invasion. Epithelial and stromal cells were isolated from human endometrium and treated for 24 h with activin, inhibin, activin/inhibin, and follistatin. Media were collected and subjected to gelatin and caesin zymography. In epithelial cells, activin A stimulated the expression of latent forms of MMPs-1, -2, -7 and -9, and increased formation of active forms of MMPs-2 and -7. Cotreatment with inhibin prevented this stimulation, whilst inhibin alone completely inhibited MMP production. Treatment with follistatin treatment reduced MMP levels. Similar regulation was seen in stromal cells for MMPs-1, -2 and -9. These data show that activin stimulates the production and activation of MMPs in both endometrial cells, and that inhibin is a potent inhibitor. It is interesting that activin is acting in an opposing manner to TGF-β, indicating that these two closely related proteins have divergent signalling pathways in endometrial cells. Further, this is the first demonstration of a role for inhibin in regulating MMPs and indeed for inhibin action in the endometrium. These findings are of potential importance in understanding regulation of MMPs in the peri-implantation endometrium. Activin is the predominant dimer produced by decidual and epithelial cells, where it may be promoting decidualisation though enhancing MMP production and activation. Furthermore, activin secretion by invasive cytotrophoblasts may stimulate focal decidual MMP production promoting their invasion during embryo implantation.

[Uveitis]

Uveitis is a general term that refers to the inflammation of uveal tract, which is an important cause of blindness in young people. It is well known that uveitis can be the initial manifestation of a systemic disease (S.D.), and may appear years before the diagnosis of the primary disease. Uveitis should be integrated in a systemic study with proper testing. Therefore, the diagnosis is a matter for the ophthalmologist and the Specialist in internal medicine. We have made a retrospective study of 71 patients with chronic uveitis or panuveitis. We found 54.9% of primary uveitis and 45.1% of S.D. associated uveitis, most of them with Behçet's disease (16/71) and Ankylosing Spondilytis (7/71). HLA typing of the patients showed a decreased frequency of HLA A1 and HLA A3 antigens and an increased frequency of the HLA B27 antigen, when compared to a Portuguese control population. We confirmed the important role of HLA B27 as an independent susceptibility factor for anterior uveitis. The lowest HLA A3 frequency was observed in the group of S.D. associated uveitis, which could suggest that this antigen may play a role as a factor of resistance to uveitis.