Perioperative Management of a Frail Patient With Bernard-Soulier Syndrome

Bernard-Soulier syndrome (BSS) is an autosomal recessive inherited bleeding disorder characterized by prolonged bleeding time, thrombocytopenia, and giant platelets. Patients with BSS are at an increased risk of bleeding, especially during traumatic injury and surgical procedures. The literature on the anesthetic management of patients with BSS is limited. In this report, we detail the successful management of a frail patient with BSS who underwent a major surgical procedure. Despite comprehensive clinical monitoring and an extended pharmacological strategy, a hemorrhagic complication occurred in the later postoperative phase, emphasizing the necessity for continued support and vigilant clinical monitoring due to the ongoing bleeding risk associated with these patients. In this case, a combined strategy involving antifibrinolytics, recombinant factor VII, and platelet transfusions proved effective.

Final analysis of phase II results with cemiplimab in metastatic basal cell carcinoma after hedgehog pathway inhibitors

BACKGROUND

Metastatic basal cell carcinoma (mBCC) is a rare condition with no effective second-line treatment options. Cemiplimab is an immune checkpoint inhibitor that blocks the binding of programmed cell death-1 (PD-1) to its ligands, programmed death-ligand 1 (PD-L1) and programmed death-ligand 2 (PD-L2). Here, we present the final analysis of cemiplimab in patients with mBCC after first-line hedgehog pathway inhibitor (HHI) treatment (NCT03132636).

PATIENTS AND METHODS

In this open-label, single-arm, phase II study, adults with mBCC and Eastern Cooperative Oncology Group performance status ≤1, post-HHI treatment, received cemiplimab 350 mg intravenously every 3 weeks for ≤93 weeks or until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) by independent central review (ICR). Duration of response (DOR) was a key secondary endpoint. Other secondary endpoints were ORR per investigator assessment, progression-free survival (PFS), overall survival (OS), complete response rate, safety, and tolerability.

RESULTS

Fifty-four patients were enrolled: 70% were male and the median age of patients was 64 [interquartile range (IQR) 57.0-73.0] years. The median duration of follow-up was 8 months (IQR 4-21 months). The ORR per ICR was 22% [95% confidence interval (CI) 12% to 36%], with 2 complete responses and 10 partial responses. Among responders, the median time to response per ICR was 3 months (IQR 2-7 months). The estimated median DOR per ICR was not reached [95% CI 10 months-not evaluable (NE)]. The disease control rate was 63% (95% CI 49% to 76%) per ICR and 70% (95% CI 56% to 82%) per investigator assessment. The median PFS per ICR was 10 months (95% CI 4-16 months); the median OS was 50 months (95% CI 28 months-NE). The most common treatment-emergent adverse events were fatigue [23 (43%)] and diarrhoea [20 (37%)]. There were no treatment-related deaths.

CONCLUSIONS

Cemiplimab demonstrated clinically meaningful antitumour activity, including durable responses, and an acceptable safety profile in patients with mBCC who had disease progression on or intolerance to HHI therapy.

POS1264 LONGITUDINAL FOLLOW-UP OF HUMORAL RESPONSE AGAINST SARS-CoV-2 AND VIRAL PERSISTENCE IN 96 DMARDs-TREATED PATIENTS WITH PREVIOUS COVID-19 INFECTION

Background

Although it prevents severe forms of the disease, vaccination does not completely protect against the occurrence of COVID19 disease. If, DMARDs used have been associated with variable humoral response to SARS-CoV-2 vaccination, the impact of their use after SARS-CoV-2 natural infection have been poorly studied.

Objectives

To characterize humoral response after SARS-CoV-2 infection and viral persistence in the nasopharyngeal sphere (NP), stools and blood of patients with rheumatic disease under DMARDs, and compared to healthy controls.

Methods

Prospective monocentric longitudinal study including patients with rheumatoid arthritis or spondyloarthritis under DMARDs and with a confirmed SARS-CoV-2 infection (positive NP PCR and/or positive serology and/or pathognomonic thoracic tomography (CT)) during the first or second wave of the COVID pandemic. Patients were followed up until one year after infection and humoral response was assessed before vaccination. Serum IgG and IgA antibodies against spike (S) and nucleocapsid (N) proteins were measured at every visit. Viral persistence was assessed at the early visit in the NP and stools using conventional RT-PCR and in the blood using a high sensitive technique (droplet digital PCR).

Results

Between June 2020 and July 2021, we include 96 patients (50 SpA and 46 RA) with a mean age of 53 +/- 14 years and 20 healthy controls (mean age 49 ± 16 years) corresponding to relatives of patients (spouses, children) living together and infected at the same time. The immune responses were analyzed according to 6 treatment groups: methotrexate (MTX)/salazopyrine (SLZ) monotherapy (n=17/2); anti-TNF monotherapy (n=24), anti-TNF + MTX (n=23); rituximab (RTX) (n=11); anti-IL17 or -23 (n=8); others (n=11). Visits were made at 1 month (29 ±13 days; n=18), 3 months (110 ±23 days; n=67), 6 months (231 ±35 days; n=48) and 12 months (368 ± 19 days; n=19) after infection. The anti-S and anti-N IgG Ab titers were not significantly different in the 6 treatment groups and the control population at 3 months. A significant decrease in anti-S IgA Ab titers was noted in the group treated with RTX (p=0.007) and with molecules targeting the IL17/23 pathway (p=0.007). A similar but non-significant trend was observed in these same treatment groups for anti-N IgA Ab (p=0.07). The titers of anti-SARS-CoV-2 antibodies at M3, was not associated with a severe COVID disease. Detection of SARS-Cov-2 RNA in stools and serum was negative for all samples taken at 1 month or 3 months. 4 patients (2 RA treated with abatacept/RTX and 2 SpA treated with anti-TNF/secukinumab) had a positive RT-PCR NP with low to very low viral load at the 1-month visit (mean Ct 36). None of these 4 patients had had a severe form of COVID19 infection.

Conclusion

DMARDs - treated patients with previous proven COVID-19 did not seem to alter IgG Ab response but RTX and anti-IL17/-IL-23 might alter IgA humoral response. This lower immune response was not associated with a more severe disease. In these patients, new infection may not be considered as a full boost for the immune system. DMARDs did not induce viral persistence in the serum, the NP or in the stool.

Acknowledgements

financial support from Société Française de Rhumatologie and ANR RA COVID

Disclosure of Interests

None declared

Electrocardiographic imaging a valid tool or an inaccurate toy?

Funding Acknowledgements

Type of funding sources: Private hospital(s). Main funding source(s): Learning Health

Background and aim

Electrocardiographic imaging (ECGI) is capable of performing an activation map with a single beat. However, previous studies using the epicardial-only system, have suggested a bad accuracy for the assessment of the epicardial breakthrough. Recent systems using endo-epicardial analysis have shown promising results. The aim of this study was to assess the accuracy and reproducibility of two endo-epicardial ECGI systems using different cardiac sources one based on the extracellular-potential, and the other on the equivalent double layer model, respectively the AMYCARD (EP Solutions SA, Switzerland) and VIVO (Catheter Precision, NJ USA) systems.

Methods

We studied 11 consecutive patients referred for ablation of frequent idiopathic premature ventricular contractions at our center that had an ECGI performed using both systems on the same day. The AMYCARD system uses a dense array of body-surface electrocardiograms with up to 224 leads and VIVO uses just the 12-leads ECG. Both systems use a patient-specific heart torso geometry obtained with a CT-scan or cardiac magnetic resonance. The localisation of the PVCs based on ECGI was done using a segmental model with 22 segments on the left ventricle, to include the classical 17 segment model plus the aortic cusps and the papillary muscles, and 12 segments on the right ventricle including 4 on the right ventricular outflow tract (RVOT): (anterior, lateral, right septum and left septum). A perfect match was defined as a predicted location within the same anatomic segment, whereas a near match as a predicted location within the same segment or a contiguous one.

Results

The median (Q1-Q3) number of leads used for the AMYCARD was 131 (118-144). Seven patients underwent ablation and in 4 ablation is pending. The predicted locations and the ablation site are depicted on the Table. We found a perfect match between both systems in 73% (Figure) and near match in 91% of cases. In patients that underwent ablation the systems localised the site of origin of the PVCs within the same segment or the contiguous segment in all patients with VIVO and in six out of seven with AMYCARD.

Conclusions

ECGI is an accurate diagnostic tool with reproducible results regardless the cardiac source used for analysis.

Assessment of activation duration across the right ventricular outflow tract in patients with premature ventricular contractions using noninvasive electrocardiographic mapping: a validation study

Funding Acknowledgements

Type of funding sources: Private hospital(s). Main funding source(s): Learning Health

Introduction

Previous studies have reported that wavefront propagation speed across the right ventricular outflow tract (RVOT) can distinguish premature ventricular contractions (PVCs) with a RVOT origin from PVCs with a left ventricular outflow tract (LVOT) origin.

Aim

Validate the non-invasive electrocardiographic mapping (ECGI) for assessment of RVOT activation duration (AD) during PVCs and assess its value as a predictor of the origin of the PVCs.

Methods

We studied 18 consecutive patients, 8 males, median age 55 (35-63) years that underwent ablation of frequent (> 10.000 per 24 h) idiopathic PVCs with inferior axis, that had and an ECGI performed before ablation and the RVOT mapped in PVC. The ECGI was performed with the Amycard system, and invasive mapping was performed with the Carto or Ensite system. Isochronal activation maps of the RVOT in PVC were obtained with the activation direction method (ADM) of the ECGI, and with the Carto and Ensite systems. Total RVOT AD was measured as the time interval between the earliest and the latest activated region. Agreement between the two methods was performed using a Bland-Altman plot and linear regression . The cutoff value of AD to predict PVC origin was calculated with ROC curve.

Results

PVCs originated from the RVOT in 11 (61%) patients. The median (Q1-Q3) RVOT AD measured with ECGI was 54 (39-68) ms and with invasive map 57 (36-70) ms. The agreement between both methods was good with an R2 of 0.747, p<0.0001. Figure displays the Bland-Altman plot (panel A), the linear regression plot (panel B). and two examples of the ECGI isochronal map (panel C). The AD was significantly higher in PVCs from the RVOT vs LVOT, both with ECGI and Carto, respectively 62 (58-73) vs 37 (33-40) ms, p<0.0001 and 68 (60-75) vs 34 (30-40) ms, p<0.0001. The cutoff value of 43 ms for AD measured with ECGI, predicted the origin of the PVCs with a sensitivity and specificity of 100%.

Conclusions

We found good agreement between ECGI and Carto. The AD obtained with ECGI was accurate to predict the origin of the PVCs.

Defects in mucosal immunity and nasopharyngeal dysbiosis in HSC-transplanted SCID patients with IL2RG/JAK3 deficiency

Both innate and adaptive lymphocytes have critical roles in mucosal defense that contain commensal microbial communities and protect against pathogen invasion. Here we characterize mucosal immunity in patients with severe combined immunodeficiency (SCID) receiving hematopoietic stem cell transplantation (HSCT) with or without myeloablation. We confirmed that pretransplant conditioning had an impact on innate (natural killer and innate lymphoid cells) and adaptive (B and T cells) lymphocyte reconstitution in these patients with SCID and now show that this further extends to generation of T helper 2 and type 2 cytotoxic T cells. Using an integrated approach to assess nasopharyngeal immunity, we identified a local mucosal defect in type 2 cytokines, mucus production, and a selective local immunoglobulin A (IgA) deficiency in HSCT-treated SCID patients with genetic defects in IL2RG/GC or JAK3. These patients have a reduction in IgA-coated nasopharyngeal bacteria and exhibit microbial dysbiosis with increased pathobiont carriage. Interestingly, intravenous immunoglobulin replacement therapy can partially normalize nasopharyngeal immunoglobulin profiles and restore microbial communities in GC/JAK3 patients. Together, our results suggest a potential nonredundant role for type 2 immunity and/or of local IgA antibody production in the maintenance of nasopharyngeal microbial homeostasis and mucosal barrier function.

Trained ILC3 responses promote intestinal defense

Group 3 innate lymphoid cells (ILC3s) are innate immune effectors that contribute to host defense. Whether ILC3 functions are stably modified after pathogen encounter is unknown. Here, we assess the impact of a time-restricted enterobacterial challenge to long-term ILC3 activation in mice. We found that intestinal ILC3s persist for months in an activated state after exposure to Citrobacter rodentium. Upon rechallenge, these "trained" ILC3s proliferate, display enhanced interleukin-22 (IL-22) responses, and have a superior capacity to control infection compared with naïve ILC3s. Metabolic changes occur in C. rodentium-exposed ILC3s, but only trained ILC3s have an enhanced proliferative capacity that contributes to increased IL-22 production. Accordingly, a limited encounter with a pathogen can promote durable phenotypic and functional changes in intestinal ILC3s that contribute to long-term mucosal defense.

Release of infectious virus and cytokines in nasopharyngeal swabs from individuals infected with non-alpha or alpha SARS-CoV-2 variants: an observational retrospective study

BACKGROUND

The dynamics of SARS-CoV-2 alpha variant shedding and immune responses at the nasal mucosa remain poorly characterised.

METHODS

We measured infectious viral release, antibodies and cytokines in 426 PCR+ nasopharyngeal swabs from individuals harboring non-alpha or alpha variants.

FINDINGS

With both lineages, viral titers were variable, ranging from 0 to >106 infectious units. Rapid antigenic diagnostic tests were positive in 94% of samples with infectious virus. 68 % of individuals carried infectious virus within two days after onset of symptoms. This proportion decreased overtime. Viable virus was detected up to 14 days. Samples containing anti-spike IgG or IgA did not generally harbor infectious virus. Ct values were slightly but not significantly lower with alpha. This variant was characterized by a fast decrease of infectivity overtime and a marked release of 13 cytokines (including IFN-b, IP-10 and IL-10).

INTERPRETATION

The alpha variant displays modified viral decay and cytokine profiles at the nasopharyngeal mucosae during symptomatic infection.

FUNDING

This retrospective study has been funded by Institut Pasteur, ANRS, Vaccine Research Institute, Labex IBEID, ANR/FRM and IDISCOVR, Fondation pour la Recherche Médicale.

Development of a highly specific and sensitive VHH-based sandwich immunoassay for the detection of the SARS-CoV-2 nucleoprotein

The current COVID-19 pandemic illustrates the importance of obtaining reliable methods for the rapid detection of SARS-CoV-2. A highly specific and sensitive diagnostic test able to differentiate the SARS-CoV-2 virus from common human coronaviruses is therefore needed. Coronavirus nucleoprotein (N) localizes to the cytoplasm and the nucleolus and is required for viral RNA synthesis. N is the most abundant coronavirus protein, so it is of utmost importance to develop specific antibodies for its detection. In this study, we developed a sandwich immunoassay to recognize the SARS-CoV-2 N protein. We immunized one alpaca with recombinant SARS-CoV-2 N and constructed a large single variable domain on heavy chain (VHH) antibody library. After phage display selection, seven VHHs recognizing the full N protein were identified by ELISA. These VHHs did not recognize the nucleoproteins of the four common human coronaviruses. Hydrogen Deuterium eXchange–Mass Spectrometry (HDX-MS) analysis also showed that these VHHs mainly targeted conformational epitopes in either the C-terminal or the N-terminal domains. All VHHs were able to recognize SARS-CoV-2 in infected cells or on infected hamster tissues. Moreover, the VHHs could detect the SARS variants B.1.17/alpha, B.1.351/beta, and P1/gamma. We propose that this sandwich immunoassay could be applied to specifically detect the SARS-CoV-2 N in human nasal swabs.

TAVI via alternative access routes: patient selection and 10-year center experience

Background

Femoral access is considered the gold standard for transcatheter aortic valve implantation (TAVI). However, this route might be precluded due to the presence of tortuosity, small vessel diameter and/or peripheral artery disease. We aimed to investigate TAVI through an alternative access (AA), focusing on the selection criteria and clinical outcomes compared to the femoral route (TF).

Methods

We conducted an all-comers longitudinal single-centre prospective registry in whom a TAVI was performed. The feasibility, safety and efficacy of TAVI by means of an access route other than standard TF was assessed, according to the VARC-2 criteria. The prospective surgical criteria used at our institution to accept an AA route were: a) TF deemed inappropriate; b) acceptable haemorrhagic risk; c) acceptable general anaesthesia risk; and d) adequate anatomy and diameter within acceptable range (subclavian, axillar, transaortic) or e) age <85 years and non-frail patient (transapical). The primary endpoint was all-cause death at 1-year.

Results

From 2008 to 2018, there were 548 patients submitted to TAVI [median age 84 (79–87) years, males 45.4%]. An AA route was used in 100 patients (79 trans-apical, 9 trans-aortic, and 12 trans-subclavian), with a decreasing rate over follow-up (−11% per year). Compared to TF, these patients were younger [80 (77–84) vs. 85 (80–87) years; p<0.001) with a similar baseline surgical risk as per EuroSCORE II [5.1 (3.3–9.0) vs. 4.7 (3.3–7.0); p=0.410). AA patients presented a higher burden of atherosclerotic disease, namely coronary (54.0 vs. 41.3%; p<0.001) and peripheral artery disease (35.0 vs. 16.5%, p<0.001) despite a lower number of other comorbidities (e.g. glomerular filtration rate <50mL/min: 53.1 vs. 64.8%; p=0.030). Left ventricular ejection fraction (56±13 vs 55±12%; p=0.203) and aortic stenosis severity (e.g. valve area: 0.70±0.19 vs. 0.67±0.18cm2; p=0.302) were similar between groups. Haemorrhagic events (minor or major) following TAVI were less often documented in the AA group (11.0 vs 21.7%; p=0.015), contrasting with de novo atrial fibrillation (18.5 vs 7.6%; p=0.048). Overall, 67 patients met the primary endpoint (18.8 vs 16.2%; p=0.584). After adjusted multivariate analysis, the independent predictors of one-year mortality did not include the TAVI access route.

Conclusion

In the first 10 years of experience, 1 in every 6 patients was treated with a TAVI by means of an AA, most often trans-apically initially and, nowadays, via a trans-subclavian approach. The use of meticulous prospective selection criteria seems to explain the one-year similar results, regardless of the access route.

Funding Acknowledgement

Type of funding sources: None.

A monocyte/dendritic cell molecular signature of SARS-CoV-2-related multisystem inflammatory syndrome in children with severe myocarditis

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children is generally milder than in adults, but a proportion of cases result in hyperinflammatory conditions often including myocarditis.

Methods

To better understand these cases, we applied a multiparametric approach to the study of blood cells of 56 children hospitalized with suspicion of SARS-CoV-2 infection. Plasma cytokine and chemokine levels and blood cellular composition were measured, alongside gene expression at the bulk and single-cell levels.

Findings

The most severe forms of multisystem inflammatory syndrome in children (MIS-C) related to SARS-CoV-2 that resulted in myocarditis were characterized by elevated levels of pro-angiogenesis cytokines and several chemokines. Single-cell transcriptomics analyses identified a unique monocyte/dendritic cell gene signature that correlated with the occurrence of severe myocarditis characterized by sustained nuclear factor κB (NF-κB) activity and tumor necrosis factor alpha (TNF-α) signaling and associated with decreased gene expression of NF-κB inhibitors. We also found a weak response to type I and type II interferons, hyperinflammation, and response to oxidative stress related to increased HIF-1α and Vascular endothelial growth factor (VEGF) signaling.

Conclusions

These results provide potential for a better understanding of disease pathophysiology.

Funding

Agence National de la Recherche (Institut Hospitalo-Universitaire Imagine, grant ANR-10-IAHU-01; Recherche Hospitalo-Universitaire, grant ANR-18-RHUS-0010; Laboratoire d’Excellence ‘‘Milieu Intérieur,” grant ANR-10-LABX-69-01; ANR-flash Covid19 “AIROCovid” and “CoVarImm”), Institut National de la Santé et de la Recherche Médicale (INSERM), and the “URGENCE COVID-19” fundraising campaign of Institut Pasteur.

Children with SARS-CoV-2 infection were initially thought to have only mild COVID-19 symptoms. However, several weeks into the first wave of SARS-CoV-2 infections, there was a surge of a postacute pathology called multisystem inflammatory syndrome in children (MIS-C). The authors recruited a cohort of children with suspicion of SARS-CoV-2 infection and uncovered hyperinflammation, hypoxic conditions, exacerbation of TNF-α signaling via NF-κB, and absence of responses to type I and type II IFN secretion in the most severe forms of MIS-C with severe myocarditis. This work led the authors to identify in monocytes and validate in peripheral blood mononuclear cells a molecular signature of 25 genes that allows discrimination of the most severe forms of MIS-C with myocarditis.

Distinct systemic and mucosal immune responses during acute SARS-CoV-2 infection

Coordinated local mucosal and systemic immune responses following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection either protect against coronavirus disease 2019 (COVID-19) pathologies or fail, leading to severe clinical outcomes. To understand this process, we performed an integrated analysis of SARS-CoV-2 spike-specific antibodies, cytokines, viral load and bacterial communities in paired nasopharyngeal swabs and plasma samples from a cohort of clinically distinct patients with COVID-19 during acute infection. Plasma viral load was associated with systemic inflammatory cytokines that were elevated in severe COVID-19, and also with spike-specific neutralizing antibodies. By contrast, nasopharyngeal viral load correlated with SARS-CoV-2 humoral responses but inversely with interferon responses, the latter associating with protective microbial communities. Potential pathogenic microorganisms, often implicated in secondary respiratory infections, were associated with mucosal inflammation and elevated in severe COVID-19. Our results demonstrate distinct tissue compartmentalization of SARS-CoV-2 immune responses and highlight a role for the nasopharyngeal microbiome in regulating local and systemic immunity that determines COVID-19 clinical outcomes.

Patterns of revascularization in stable ischemic heart disease in the pre-ISCHEMIA era

Introduction

New evidence on the role of myocardial revascularization in stable ischemic heart disease (SIHD), recently presented, showed that revascularization guided by the presence of moderate-to severe ischemia relieves angina more effectively than optimal medical therapy (OMT), without a significant benefit in hard clinical endpoints.

Aim

To assess the representativeness of the ISCHEMIA trial in a real-world population and compare management strategies between patients who fulfill the eligibility criteria of the trial (Group 1, G1) and those who do not (Group 2, G2).

Methods and population

Single centre retrospective analysis including all consecutive patients referred to coronary angiography (CA) for SIHD from January 2018 to December 2019. Patients were stratified in two groups (G1 and G2) according to the ISCHEMIA trial inclusion and exclusion criteria. G1 was compared with G2 and with a subset of G2 with obstructive coronary artery disease (CAD), defined as ≥70% luminal stenosis in at least one coronary artery or >50% for the left main.

Results

A total of 1020 patients underwent CA, of whom only 124 (12.2%) would have been eligible for the ISCHEMIA trial (G1). Overall, there were no significant differences in baseline characteristics between the two groups. G1 patients had more extensive and severe disease, presenting more frequently with proximal left anterior descending (LAD) involvement (26.6% vs 10.4%; p<0.001), two vessel disease without proximal LAD stenosis (23.4% vs 10.3%; p<0.001) and three vessel disease (18.5% vs 5.9%; p<0.001). These patients had higher rates of revascularization, both CABG (25.8% vs 10.8%, p<0.001) and PCI (56.5% vs 39.5%, p<0.001). However, when comparing G1 with the subset of G2 patients with obstructive CAD, G1 patients had higher rates of CABG (26.8% vs 17.8%, p=0.034) but there were no differences on the rates of PCI (58.0% vs 56.9%, p=0.916).

Conclusions

Patients included in the ISCHEMIA trial are underrepresented in a real-world population of SIHD patients referred to coronary angiography. PCI rates were similar among patients with at least one significant coronary artery stenosis, regardless of previous evidence or severity of ischemia. Our findings underline the need for further refinement in criteria for revascularization in SIHD.

Funding Acknowledgement

Type of funding source: None

Predicting pacemaker implantation after TAVR with procedural CT

Background and aim

The need for permanent pacemaker implantation (PPMI) is a burdensome complication of transcatheter aortic valve replacement (TAVR). Calcium distribution in the aortic-valvular complex (AVC) and, more recently, membranous septum (MS) length seem to be surrogate markers for conduction abnormalities after specific last generation balloon and self-expandable expandable valves. We sough to evaluate whether such pre-procedural association remains across the entire device spectrum.

Methods

Single-centre prospective study of 239 consecutive patients (140 women, median age of 84) with severe symptomatic aortic stenosis patients who underwent ECG-gated contrast-enhanced multi-detector computed tomography (MSCT) before TAVR since Jun/2017. Exclusion criteria were those with previous PPMI, previous bioprothesis, congenital bicuspid valve, and poor imaging quality. The J-score with an 850-Hounsfield unit threshold was used to detect areas of calcium in the region of interest. AVC was characterized by leaflet sector and region, using 3mensio Valves software 7.0 TM. An independent team retrospectively measured MS length blindly by determining the thinnest part of the interventricular septum in the coronal view in the better-defined systolic phase (usually at 40% of the R-R interval, Figure). Device selection (75.8% self-expandable devices, 20.1% balloon expandable, 3.1% other) and positioning were performed according to the operator criteria. Final implant depth was assessed based on the pre-release angiogram or final aortography.

Results

Mortality at 30-days was 1.3% and PPMI occurred in 43 patients (18%). Median MS length was 9.59mm (IQR: 3.11mm). After multivariable logistic regression analysis, MS length emerged as the single significant protective predictor for PPMI (OR: 0.14; 95% 95% CI: 0.05–0.42; p<0.001), independently of the device used (p<0.001). MS length showed strong discriminatory ability for PPMI (c-statistic 0.93; 95% CI 0.88–0.99). Sensitivity/specificity decision plots yielded an MS length of 6.9 mm as the optimal cut-off point for predicting the need for PPMI with a positive and negative predictive value of 91% and 93%, respectively (Figure). There wasn't any calcium accumulation within a specific region of AVC that independently predicted the outcome.

Conclusion

In our experience, a short membranous septum was strongly and independently associated with new permanent pacemaker implantation, regardless of the device type.

Our findings suggest that this simple measure should be routinely made to help device selection and implantation technique.

Funding Acknowledgement

Type of funding source: None

LV replacement fibrosis in aortic stenosis: prevalence and relation to LV remodelling and function

Background

Progressive myocardial fibrosis takes part in left ventricular (LV) remodeling in aortic stenosis (AS) and drives the transition from hypertrophy to heart failure. Replacement fibrosis may be characterized by late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR).

Aim

To assess the prevalence and association between LGE and indexes of LV function in patients with severe aortic stenosis.

Methods

We prospectively studied 53 consecutive patients (age: 71±8 years [min. 51–max. 84], 54.7% men) with severe symptomatic AS, referred for surgical aortic valve replacement with no previous history of ischemic cardiomyopathy. Aortic valve mean gradient was 54.6 mmHg [IQR 46.6–63.2] and aortic valve area 0.74cm2 [IQR 0.61–0.89]; all patients with high gradient, 4 with low-flow. CMR with tissue characterization (T1 mapping, LGE and extracellular volume by ECV quantification – using 5SD from remote myocardium as signal intensity cut-off), was performed before surgery. AS severity indexes, LV mass, systolic and diastolic LV function indexes including global longitudinal strain (GLS) and torsion were compared in both groups of patients, with and without LGE.

Results

Mid-wall LGE was present in 36 patients (67.9%) with a median fraction of 6.0% [IQR 4.9–12.7%] of LV mass. Native T1 value and ECV were within normal ranges (median values: 1047ms [IQR 1028–1084]; 22% [IQR 18–25], respectively). Median CMR LV ejection fraction and mass were 64.5% [IQR 51.3–70.8%] (11 patients with reduced EF) and 76.5g/m2 [IQR 57.4–94.8g/m2], respectively. Median GLS was −13.9% [IQR −11.4 to −17.0%] and torsion was 24.2° [IQR 19.8–32.5°]. Patients with LGE had significantly higher LV mass (87.1g/m2 vs 63.3 g/m2, p=0.001), worse GLS (−14.4% vs −16.9%, p=0.041) and higher NT-proBNP values (1333.7ng/mL vs 559.9ng/mL, p=0.004) (Figure).

Conclusions

Non-ischemic LGE is common in this group of patients with severe symptomatic high gradient aortic stenosis. As it is more prevalent in patients with more pronounced LVH, lower longitudinal deformation and higher NT-proBNP values, it probably represents a more advanced stage of the disease.

Funding Acknowledgement

Type of funding source: None

Dysregulation of tryptophan catabolism at the host-skin microbiota interface in hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic skin disorder of unknown etiology that manifests as recurrent, painful lesions. Cutaneous dysbiosis and unresolved inflammation are hallmarks of active HS, but their origin and interplay remain unclear. Our metabolomic profiling of HS skin revealed an abnormal induction of the kynurenine pathway of tryptophan catabolism in dermal fibroblasts, correlating with the release of kynurenine pathway–inducing cytokines by inflammatory cell infiltrates. Notably, overactivation of the kynurenine pathway in lesional skin was associated with local and systemic depletion in tryptophan. Yet the skin microbiota normally degrades host tryptophan into indoles regulating tissue inflammation via engagement of the aryl hydrocarbon receptor (AHR). In HS skin lesions, we detected contextual defects in AHR activation coinciding with impaired production of bacteria-derived AHR agonists and decreased incidence of AHR ligand-producing bacteria in the resident flora. Dysregulation of tryptophan catabolism at the skin-microbiota interface thus provides a mechanism linking the immunological and microbiological features of HS lesions. In addition to revealing metabolic alterations in patients with HS, our study suggests that correcting AHR signaling would help restore immune homeostasis in HS skin.

Loss of homeostasis of tryptophan metabolism at the host-microbiota interface may contribute to Hidradenitis Suppurativa.

P955Non-invasive mapping: what is the minimal number of electrodes needed to obtain a good spatial resolution of the activation map?

Introduction and aims

The 12-lead ECG is highly inaccurate for localization of the site of origin of supraventricular and ventricular arrhythmias.  Non-invasive mapping systems (ECGI) based on a high number of electrodes recording the electrical activity on the surface of the torso have already proven good accuracy for mapping different arrhythmic substrates. The aim of this study was to assess what is the minimal number of leads needed to obtain a precise mapping with the ECGI.

Methods

This study enrolled 14 patients (9 male, median age 50 (44-58) years) referred to our center for catheter ablation of premature ventricular contractions (PVC). Patients underwent pre-procedural ECGI using the epicardial and endocardial mapping system . This system uses the DICOM images from contrast computed tomography of the heart and up to 28 adhesive electrodes with 8 leads each, adding up to 224 body-surface leads. All patients underwent invasive electroanatomical mapping and ablation with the magnetic navigation system. We analysed the number of recording leads used to construct the non-invasive activation map of the PVCs and the accuracy and the spatial resolution of the map when comparing to the invasive map. We then reprocessed the exam, using progressively less leads until we only left the leads placed in the standard 12 lead ECG positions and evaluated the concordance with the invasive map as well as the spatial resolution. We considered an earliest activation site (EAS) area of 1 cm2 a good spatial resolution and using a ROC curve we calculated the minimal number of leads necessary to obtain a good spatial resolution.

Results

The median number of electrodes used for the initial map was 170 (138-177). Concordance between non-invasive and invasive site of origin occurred in 11 out of 14 patients. The results are presented in the Table. The minimal number of electrodes to have a good spatial resolution was 100. The area of EAS was significantly lower when using more than 100 leads, respectively 0.65 (0.5-1) cm2 versus 3 (1.6-5) cm2, p < 0.001.

Conclusions

The minimal number of leads to achieve a good spatial resolution was high.  Reducing the number of leads resulted in a significant decrease in spatial resolution and a lower concordance rate.

ECGI data Number of adhesive electrodes Median number of leads Amycard/Carto concordance Median area of EAS in the ECGI (cm2) Maximal nº electrodes 170 (138-177) 11/14 0.64 (0.5-0.9) 12 electrodes 76 (61-80) 11/14 1.6 (1.4-2.6) 6 electrodes (2 Ant, 2 Lat ,2 Post) 38 (32-44) 9/14 4.3 (3.2-5.4) 12 leads 12 0/14 - Ant anterior; Lat: lateral; Post: posterior; EAS: early activation site.

Abstract Figure. Area of EAS according to the N of leads

P5702Non-invasive epicardial and endocardial mapping in patients with idiopathic right ventricular outflow tract premature ventricular contractions: new insights into arrhythmia substrate

Background

It has been accepted for years that idiopathic premature ventricular contractions (PVCs) with origin in the right ventricular outflow tract (RVOT) are benign. They are thought to result from triggered activity and most studies do not describe abnormal findings during electroanatomical mapping

Dispersion of ventricular repolarization is associated with the susceptibility to ventricular arrhythmias and may indicate the presence of diseased myocardium. The activation recovery interval (ARI) has been used as a surrogate measure of ventricular action potential duration and refractory period.

Purpose

The aim of this study was to use the new non-invasive epicardial and endocardial mapping system (NEES) to study patients with RVOT PVCs in order to evaluate the ARI in the epicardium of RVOT during sinus rhythm (SR).

Methods

Non-invasive mapping was performed with the NEES, based on body surface electrocardiograms of a maximum of 224 electrodes and computed tomography imaging data. Unipolar electrograms were reconstructed on the epicardial and endocardial surfaces. Patients were excluded if they had structural heart disease, previous ablation or conduction abnormalities. ARI was defined as the interval between times of minimum derivative of the QRS and the maximum derivative of the T wave in the unipolar electrograms. We evaluated the ARI map in patients with RVOT PVCs and in a control group of patients without PVCs (Figure). We assessed the maximum value of ARI (Max ARI), the minimum value of ARI (Min ARI) and the difference between the Max ARI and the Min ARI (Diff ARI).

Results

We studied 8 patients with RVOT PVCs and 8 patients without PVCs.

The results are presented in the table.

Demographic and NEES data RVOT PVCs (n=8) Control (n=8) P value* Demographic data   Age in years, median (IQR) 53 (48–65) 59 (52–67) 0.536   Male gender, n (%) 4 (50) 6 (75) 0.608 NEES data   Max ARI in msec, median (IQR) 285 (236–331) 228 (197–298) 0.195   Min ARI in msec, median (IQR) 176 (138–192) 216 (185–255) 0.161   ARI diff in msec, median (IQR) 111 (83–147) 15 (4–34) <0.0001

NEES map

Conclusion

In this group of patients we found a significantly higher dispersion of the ARI measurements through the epicardium of the RVOT in patients with PVCs in comparison with patients without PVCs.

Restitution volumes at the end of dialysis sessions: A potential influencing factor on patients' haemoglobin levels?

AIM

To evaluate whether haemoglobin (Hb) levels are influenced by the restitution volume (RestVol) at the end of the dialysis session, independently of erythropoiesis-stimulating agents (ESA) and iron doses.

DESIGN

Over 12 months, 4,386 haemodialysis patients from 34 centres were enrolled in this observational descriptive study according to the checklist STrengthening the Reporting of Observational Studies in Epidemiology (STROBE).

METHOD

RestVol, Hb levels, ESA and iron doses of every patient were assessed on a monthly basis. To determine the ideal RestVol, the clinics were classified into three groups according to the restitution volumes at the end of the dialysis sessions.

RESULTS

Mean age was 69 ± 14 years, and 58.9% were men. The evaluation of 665,712 treatments revealed that RestVol of 380 ml seems to be the most efficient, since the clinics in this group managed to reduce ESA consumption with a negligible reduction in Hb levels.

Non-invasive electrocardiographic imaging in patients with idiopathic premature ventricular contractions from the right ventricular outflow tract: New insights into arrhythmia substrate

AIMS

The aim of this study was to use non-invasive electrocardiographic imaging (ECGI) to study the electrophysiological properties of right ventricular outflow tract (RVOT) in patients with frequent premature ventricular contractions (PVCs) from the RVOT and in controls.

METHODS

ECGI is a combined application of body surface electrocardiograms and computed tomography or magnetic resonance imaging data. Unipolar electrograms are reconstructed on the epicardial and endocardial surfaces. Activation time (AT) was defined as the time of maximal negative slope of the electrogram (EGM) during QRS, recovery time (RT) as the time of maximal positive slope of the EGM during T wave, Activation recovery interval (ARI) was defined as the difference between RT and AT. ARI dispersion (Δ ARI) and RT dispersion (Δ RT) were calculated as the difference between maximal and minimal ARI and RT respectively. We evaluated those parameters in patients with frequent PVCs from the RVOT, defined as >10.000 per 24 h, and in a control group.

RESULTS

We studied 7 patients with frequent RVOT PVCs and 17 controls. Patients with PVCs from the RVOT had shorter median RT than controls, in the endocardium and in the epicardium, respectively 380 (239-397) vs 414 (372-448) ms, p = 0.047 and 275 (236-301) vs 330 (263-418) ms, p = 0.047. The dispersion of ARI and of RT in the epicardium was higher than in controls, Δ ARI of 145 (68-216) vs 17 (3-48) ms, p = 0.001 and Δ RT of 201 (160-235) vs 115 (65-177), p = 0.019.

CONCLUSION

In this group of patients we found a shorter median RT in the endocardium and in the epicardium of the RVOT and a higher dispersion of the ARI and RT across the epicardium in patients with PVCs from the RVOT when comparing to controls.

Image analysis of immediate full-arch prosthetic rehabilitations guided by a digital workflow: assessment of the discrepancy between planning and execution

Background

A dentition with adequate function and esthetics is essential for the well-being and quality of life. A full implant-retained fixed prosthetics is an ideal solution for fully edentulous arch, however requires complex planning, surgical, and prosthetic procedure. With the help of digital workflow, it becomes a predictable and fast solution for the dentists and the patients. This retrospective study analyzed the most advanced surgical approach in full-arch rehabilitation with dental implants and immediate loading using digital workflow.

Methods

Patient records of fully edentulous jaws treated in four clinical centers in Warsaw, Poland, were evaluated. Computer-assisted planning and surgical template fabrication were done using the planning software coDiagnostiX™, based on a pre-op cone beam computed tomography (CBCT) and scanned data of a plaster model. A post-op CBCT was acquired after the placement of four to six implants by the guided system. The influence of different surgical variables on the discrepancy between planning and execution was analyzed, together with the biomechanical indices.

Results

A total of nine patient records were selected of 12 edentulous jaws treated with 62 implants. The overall mean three-dimensional (3D) offset at the implant base was 1.60 mm, at the tip 1.86 mm. The mean angle of deviation was 4.89°, the mean implant stability quotient (ISQ) 70.42, and the insertion torque 35.58 Ncm. The 3D offsets were influenced by the gender of the patient, treated jaw, the diameter, and length of the implant. The angle of deviation was affected only by the treated jaw. Insertion torque was influenced by the treated jaw, the age of the patient, the length of the implant, tooth type, and the side of the jaw.

Discussion

Bone quality of the patient and implant preparation procedure influenced the discrepancy between the planning and the execution of the digitally guided implant placement. Dense bone—mandible, posterior area, young age, and man—and multiple preparations of the implant bed—wider and longer implant—could be suggested as risk factors.

Conclusion

Digital workflow successfully enabled the immediate full-arch rehabilitation with a predictable outcome by different surgeons in multiple centers.

Fast pulsed operation of a small non-radioactive electron source with continuous emission current control

Non-radioactive electron sources are of great interest in any application requiring the emission of electrons at atmospheric pressure, as they offer better control over emission parameters than radioactive electron sources and are not subject to legal restrictions. Recently, we published a simple electron source consisting only of a vacuum housing, a filament, and a single control grid. In this paper, we present improved control electronics that utilize this control grid in order to focus and defocus the electron beam, thus pulsing the electron emission at atmospheric pressure. This allows short emission pulses and excellent stability of the emitted electron current due to continuous control, both during pulsed and continuous operations. As an application example, this electron source is coupled to an ion mobility spectrometer. Here, the pulsed electron source allows experiments on gas phase ion chemistry (e.g., ion generation and recombination kinetics) and can even remove the need for a traditional ion shutter.

Nearest-neighbor based wavelet entropy rate measures for intrapartum fetal heart rate variability

The interpretation and analysis of intrapartum fetal heart rate (FHR), enabling early detection of fetal acidosis, remains a challenging signal processing task. The ability of entropy rate measures, amongst other tools, to characterize temporal dynamics of FHR variability and to discriminate non-healthy fetuses has already been massively investigated. The present contribution aims first at illustrating that a k-nearest neighbor procedure yields estimates for entropy rates that are robust and well-suited to FHR variability (compared to the more commonly used correlation-integral algorithm). Second, it investigates how entropy rates measured on multiresolution wavelet and approximation coefficients permit to improve classification performance. To that end, a supervised learning procedure is used, that selects the time scales at which entropy rates contribute to discrimination. Significant conclusions are obtained from a high quality scalp electrode database of nearly two thousands subjects collected in a French public university hospital.

Modeling the effects of low-LET cosmic rays on electronic components

The effects of cosmic radiation in single cells, organic tissues and electronics are a major concern for space exploration and manned missions. Standard heavy ions radiation tests employ ion cocktails with energy of the order of 10 MeV per nucleon and with a linear energy transfer ranging from a few MeV cm(2) mg(-1) to hundreds of MeV cm(2) mg(-1). In space, cosmic rays show significant fluxes at energies up to the order of GeV per nucleon. The present work aims at investigating single event damage due to low-, high- and very-high-energy ions. The European Space Agency reference single event upset monitor data are used to support the discussion. Finally, the effect of ionization induced directly by primary particles and ionization induced by recoils produced in an electronic device is investigated for different types of devices.

Methodology for multifractal analysis of heart rate variability: from LF/HF ratio to wavelet leaders

The present contribution aims at proposing a comprehensive and tutorial introduction to the practical use of wavelet Leader based multifractal analysis to study heart rate variability. First, the theoretical background is recalled. Second, practical issues and pitfalls related to the selection of the scaling range or statistical orders, minimal regularity, parabolic approximation of spectrum and parameter estimation, are discussed. Third, multifractal analysis is connected explicitly to other standard characterizations of heart rate variability: (mono)fractal analysis, Hurst exponent, spectral analysis and the HF/LF ratio. This review is illustrated on real per partum fetal ECG data, collected at an academic French public hospital, for both healthy fetuses and fetuses suffering from acidosis.

Phase I pharmacokinetic (PK) and pharmacodynamic (PD) study of PF-00337210, a highly selective VEGFR inhibitor

3519

Background: PF-00337210 potently inhibits VEGFR2 phosphorylation and is >10-fold more selective, based on IC50, for VEGFR2 than other kinases (eg, KIT and PDGFRs). In vitro, PF-00337210 inhibits VEGF-mediated HUVEC survival (IC50 = 0.53 nM). In vivo, it inhibits tumor angiogenesis and human xenograft growth. Methods: The primary objectives were to determine the safety profile and MTD of PF-00337210. PK and PD (DCE-MRI at baseline and cycle [C] 1, day [D] 2) were also evaluated. The volume rate transfer constant (Ktrans) assessed VEGFR inhibitory effects on vascular permeability and perfusion. Results: To date, 29 patients (pts) with advanced solid tumors were treated with PF-00337210 at doses of 0.67–9 mg QD, 13 of whom (45%) had received prior VEGF/VEGFR inhibitors. No dose-limiting toxicities (DLTs) occurred at 0.67–8 mg QD. Two DLTs occurred at 9 mg QD: one pt had chest pain, G3 troponin I, and G3 myocardial ischemia; a second pt had significant hypertension (HTN) at the anticipated Tmax after the first dose (systolic ≥180 mmHg over 3 hrs). HTN and fatigue were the most common treatment-related adverse events (AEs). HTN occurred in 8 pts (28%); incidence and intensity corresponded with dose, but was well controlled with antihypertensive agents. Fatigue was reported in 9 pts (31%) and occurred most frequently in pts receiving ≥6 mg QD. Other AEs included nausea, anorexia, proteinuria, and diarrhea. PK data indicated that mean (%CV) t1/2 at 8 mg QD was 8.60 (81) h (n=4) and AUC0–24 was 309 (45) ng.h/mL at steady-state (SS) on C1D15. Exposures (AUC0–24) were generally linear and variability ranged from 21 to 44% across doses. The observed accumulation ratio (Rac) at SS was 1.22 (15) (n=21), which was predicted by t1/2. PF-00337210 decreased mean Ktrans (1/min) values by 22.5±11.8 (n=2), 15.2 (n=1), 5.4±4.8 (n=3), and 25.3±8.5% (n=4) at 4, 6, 8, and 9 mg QD, respectively. No objective responses were observed but 7/29 pts (24%) had stable disease. Conclusions: PF-00337210 was well tolerated with the DLTs being HTN and myocardial ischemia. The QD MTD was determined to be 8 mg. Preliminary evidence of VEGFR inhibition was shown by DCE-MRI at ≥4 mg QD. The trial is now evaluating BID dosing which may allow increased drug exposures and fewer hypertensive effects that may be related to Cmax.

[Table: see text]

144 ROLE OF GnRH ON MOUSE PRE-IMPLANTATION EMBRYONIC DEVELOPMENT IN VITRO

The interaction between GnRH and its receptor on gonadotropes within the anterior pituitary gland represents a key point for regulation of the reproduction. In addition, GnRH can act in multiple extrapituitary tissues via autocrine/paracrine mechanisms. Protein for GnRH and mRNA for both GnRH and its receptor have been detected in human uterine endometrium and oviduct as well as in embryos at the morula/blastocyst stage in the mouse and human. Therefore, we hypothesized that GnRH may have a critical role in the development of pre-implantation embryos. To address this question, we examined the effect of a GnRH agonist and antagonist on the development of mouse embryos in vitro. For these studies, 1-cell embryos were randomly allocated to culture in KSOM containing the appropriate treatment for 144 h at 37°C in a 5% CO2 in air environment. The medium was changed every 12 h and embryos were scored daily for development. The data were compared using a χ2 test. First, we wanted to determine if a GnRH agonist, histrelin, could enhance embryonic development. Embryos were cultured with (n = 35) or without (n = 36) 10 μM histrelin. The addition of histrelin did not increase morula or blastocyst formation v. control. Second, we cultured embryos in the presence of different concentrations (0, 0.001, 0.01, 0.1, 1, and 10 μM) of the GnRH antagonist, SB-75 (cetrorelix; n = 22/treatment) in order to determine its effect on embryonic development. The 10 μM SB-75 treatment blocked embryo development beyond the compact morula stage (P < 0.001). To determine if this was a receptor mediated effect, we attempted to rescue development of SB-75 treated embryos with a histrelin challenge. Our treatments consisted of control (n = 30), 10 μM histrelin (n = 27), 10 μM SB-75 (n = 29), and 10 μM SB-75 in combination with either 1 μM (n = 27) or 10 μM (n = 25) histrelin. Both levels of histrelin partially rescued the inhibition of blastocyst formation by SB-75 (P < 0.01). Next, we were interested in examining the signaling cascade activated following binding of GnRH to its receptor in pre-implantation embryos. Toward this end, we treated embryos with inhibitors of either PKC or PKA. First, embryos were cultured in the presence of 0 (n = 33), 0.1 (n = 35), 1 (n = 35), or 10 (n = 35) μM GF109203X (GFX), a PKC inhibitor. Similar to the results obtained with SB-75, treatment with 10 μM GFX significantly reduced development to the compact morula stage and completely blocked blastocyst formation. Second, we treated embryos (n = 15 to 17/treatment) with different concentrations (0, 0.01, 0.1, 0.5, or 1 mM) of the PKA inhibitor, SQ22536. In contrast to treatment with GFX, rates of blastocyst formation were decreased only by 35% (P < 0.05) at the highest concentration of SQ22536. The percentage of embryos developing to the hatched blastocyst stage was decreased in a dose-dependent manner following SQ22536 treatment (P < 0.05); however, this effect was not consistent with SB-75 inhibition of blastocyst formation. We suggest that GnRH has an important autocrine effect on early embryonic development, potentially signaling via PKC. Funding for M Montagner was provided by CAPES, Brazil.