P2555Efficacy and safety of oral anticoagulant versus antiplatelet therapy for secondary prevention of cardiovascular disease in patients without atrial fibrillation

Background

Anticoagulation is the mainstay of prevention of arterial thromboembolism in patients with atrial fibrillation, but it could be effective also in secondary prevention of patients who are in sinus rhythm.

Purpose

We performed this meta-analysis to determine relative efficacy and safety of oral anticoagulant therapy (OAC) as compared with antiplatelet therapy (APT) in patients with prevalent cerebro-cardiovascular disease without atrial fibrillation.

Methods

Our systematic review of the literature published through January 31st, 2019 sought all phase III randomized controlled trials which compare OAC with APT in patients with sinus rhythm and report at least one of the following outcomes: ischemic stroke, death, myocardial infarction, and major bleeding, assessed at the longest available follow-up. We used random-effects models to estimate summary relative risk reduction (RRR) and 95% confidence intervals (95% CI).

Results

We identified a total of 9 randomized controlled trials including a total of 34,912 patients (ASA, n=17,726; adjusted-dose warfarin, n=4,460; rivaroxaban, n=12726), with a mean follow-up of 2.2 years. When compared with antiplatelet therapy, OAC was associated with reduced risk of ischemic stroke (RRR 38%, 95% CI: 1; 47; P=0.04; I2=72%) and myocardial infarction (RRR 13%, 95% CI: 0,23; P=0.05, I2=0%), but increased risk of major bleeding (RRR −52%, 95% CI: −129; −1; P=0.04; I2=76%). Compared to antiplatelet treatment, OAC did not significantly affect the risk of all-cause death (RRR 1%, 95% CI: −9; 10; P=0.86; I2=12%).

Conclusions

In sinus rhythm patients with prevalent cardiovascular disease, OAC reduces risk of ischemic stroke and myocardial infarction, but significantly increases risk of major bleeding. The choice of antithrombotic treatment does not appear to influence all-cause mortality.

4289Clinical outcomes of percutaneous mitral valve repair in secondary mitral regurgitation: a systematic review and meta-analysis

Background

The benefit of percutaneous mitral valve repair with mitraclip (PMVR) in patients with secondary mitral regurgitation (MR) is still debated.

Methods

In order to compare the outcome of PMVR with optimal medical therapy (OMT) versus OMT alone in patients with secondary MR, we performed a systematic review and meta-analysis of 2 randomized clinical trials (RCT) and 7 non-randomized observational studies (nROS). Hazard ratios (HR) and 95% confidence intervals (CI) were pooled through inverse variance random-effect model to compute the summary effect size for all-cause mortality, cardiovascular death and cardiac-related hospitalization. Subgroup and meta-regression analysis were also performed.

Results

An overall population of 3,118 individuals (67% men; mean age, 73 years) was included: 1,775 PMVR+OMT and 1,343 OMT patients, with mean follow-up of 24±15 months. PMVR+OMT was associated with a lower risk of all-cause death (HR: 0.77; 95% CI: 0.68–0.87), cardiovascular death (HR: 0.55; 95% CI: 0.34–0.89) and cardiac-related hospitalization (HR: 0.77; 95% CI: 0.64–0.92). Meta-regression analysis showed that larger left ventricular end-diastolic volume index (LVEDVI) portends higher mortality after PMVR (p<0.001).

Conclusions

This study-level meta-analysis shows that PMVR+OMT is associated with reduced all-cause death, cardiovascular death and cardiac-related hospitalization when compared with OMT alone in secondary MR. LVEDVI is a predictive marker of efficacy, as patients with smaller LVEDVI derive the largest benefit from PMVR.

P4441Serum activity against specific G-protein coupled receptors is associated with the severity of orthostatic symptoms in patients with POTS

Background

Postural orthostatic tachycardia syndrome (POTS) is characterised by an excessive heart rate increase upon standing and orthostatic intolerance. Previous studies indicate autoimmune involvement mediated via G-protein coupled receptors (GPCRs) as a possible aetiology.

Purpose

To test if serum from POTS patients and controls activates selected GPCRs and if the activation associates with the severity of symptoms.

Methods

A total of 34 POTS patients (age 28.9 [9.9] years; 29 women) and a population-based control group of 25 healthy subjects (age 30.7 [8.6] years; 21 women) were included. The subjects performed an active standing test and completed the orthostatic hypotension questionnaire (OHQ) including ten items related to orthostatic intolerance. The OHQ composite score was calculated (range 0–10).

Sera were analysed by a FRET-based reporter system (Tango GeneBLAzer, Thermo Fischer) based on a beta-arrestin-linked transcription factor driving transgenic betalactamase transcription. HEK293M-cells over-expressing one of the GPCRs, adrenergic alpha-1 (ADRA1), adrenergic beta-2 (ADRB2), muscarinic type-2 (CHRM2) and opioid-receptor-like 1 (OPRL1) receptor were plated in 96-well optical plates and allowed to re-attach during 48 hrs. The cells were treated with 10% sera diluted in RPMI for 5 hours, followed by addition of the FRET-substrate, incubation for 60 min and quantification analysis in a CLARIOStar multi-purpose plate reader.

Quantification of the activation of the GPCRs was log-transformed and related to the OHQ composite and individual scores in age-adjusted linear regression models. OHQ scores were compared according to the median of sera activation, using independent samples t-test.

Results

Serum ADRA1 activation associated with the OHQ composite score (beta 0.77 OHQ points per SD of activity; p=0.009), whereas there were no significant associations among controls (p=0.953). The association between ADRA1 and total OHQ was significant also after adjusting for heart rate and systolic blood pressure at 3 min (p=0.024). The OHQ composite score was higher in with above median serum ADRA1 activation (Figure 1).

ADRA1 activation associated with a higher score for vision problems (p<0.001) and symptoms during prolonged standing (p=0.037) and walking for short (p=0.042) or long periods (p=0.001).

The activity of ARB2, CHRM2 and OPRL1 did not associate with OHQ composite score in neither POTS patients nor controls.

Figure 1. OHQ according to ADRA1 activation

Conclusions

Activating serum proteins for the adrenergic alpha-1 receptor are associated with the severity of orthostatic symptoms in POTS patients, partly independent of the orthostatic hemodynamic response. Serum activity against alpha1 receptors is related particularly to symptoms of disturbed vision and symptoms during walking or prolonged standing. Serum activity against the adrenergic alpha 1 receptor may be a one factor underlying the orthostatic symptoms in POTS.

Acknowledgement/Funding

The Swedish Heart-Lung Foundation, The Swedish Heart and Lung Association, Solidex, ALF funds, Crafoord Foundation, Ernhold Lundströms Foundation.

Tests of General Relativity with GW170817

The recent discovery by Advanced LIGO and Advanced Virgo of a gravitational wave signal from a binary neutron star inspiral has enabled tests of general relativity (GR) with this new type of source. This source, for the first time, permits tests of strong-field dynamics of compact binaries in the presence of matter. In this Letter, we place constraints on the dipole radiation and possible deviations from GR in the post-Newtonian coefficients that govern the inspiral regime. Bounds on modified dispersion of gravitational waves are obtained; in combination with information from the observed electromagnetic counterpart we can also constrain effects due to large extra dimensions. Finally, the polarization content of the gravitational wave signal is studied. The results of all tests performed here show good agreement with GR.

From bench to bedside: in vitro and in vivo evaluation of a neonate-focused nebulized surfactant delivery strategy

Background

Non-invasive delivery of nebulized surfactant has been a neonatology long-pursued goal. Nevertheless, the clinical efficacy of nebulized surfactant remains inconclusive, in part, due to the great technical challenges of depositing nebulized drugs in the lungs of preterm infants. The aim of this study was to investigate the feasibility of delivering nebulized surfactant (poractant alfa) in vitro and in vivo with an adapted, neonate-tailored aerosol delivery strategy.

Methods

Particle size distribution of undiluted poractant alfa aerosols generated by a customized eFlow-Neos nebulizer system was determined by laser diffraction. The theoretical nebulized surfactant lung dose was estimated in vitro in a clinical setting replica including a neonatal continuous positive airway pressure (CPAP) circuit, a cast of the upper airways of a preterm neonate, and a breath simulator programmed with the tidal breathing pattern of an infant with mild respiratory distress syndrome (RDS). A dose-response study with nebulized surfactant covering the 100–600 mg/kg nominal dose-range was conducted in RDS-modelling, lung-lavaged spontaneously-breathing rabbits managed with nasal CPAP. The effects of nebulized poractant alfa on arterial gas exchange and lung mechanics were assessed. Exogenous alveolar disaturated-phosphatidylcholine (DSPC) in the lungs was measured as a proxy of surfactant deposition efficacy.

Results

Laser diffraction studies demonstrated suitable aerosol characteristics for inhalation (mass median diameter, MMD = 3 μm). The mean surfactant lung dose determined in vitro was 13.7% ± 4.0 of the 200 mg/kg nominal dose. Nebulized surfactant delivered to spontaneously-breathing rabbits during nasal CPAP significantly improved arterial oxygenation compared to animals receiving CPAP only. Particularly, the groups of animals treated with 200 mg/kg and 400 mg/kg of nebulized poractant alfa achieved an equivalent pulmonary response in terms of oxygenation and lung mechanics as the group of animals treated with instilled surfactant (200 mg/kg).

Conclusions

The customized eFlow-Neos vibrating-membrane nebulizer system efficiently generated respirable aerosols of undiluted poractant alfa. Nebulized surfactant delivered at doses of 200 mg/kg and 400 mg/kg elicited a pulmonary response equivalent to that observed after treatment with an intratracheal surfactant bolus of 200 mg/kg. This bench-characterized nebulized surfactant delivery strategy is now under evaluation in Phase II clinical trial (EUDRACT No.:2016–004547-36).

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1096-9) contains supplementary material, which is available to authorized users.

Atopic Dermatitis Phenotypes in Preschool and School-Age Children: A Latent Class Analysis

BACKGROUND

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease in childhood. Few data are available about AD phenotypes and their nationwide distribution.

METHODS

We performed a cross-sectional multicenter study involving some of the main Italian pediatric allergy centers from 9 Italian cities. A structured questionnaire was administered to 371 children with AD. Patients were divided in 2 groups: preschool children (aged ≤5 years) and schoolchildren (aged 6-14 years). A latent class analysis was used to detect AD phenotypes and to investigate their association with risk factors and other atopic diseases.

RESULTS

Latent class analysis identified 5 AD phenotypes in preschoolers ("moderate-severe AD, high comorbidity", 8%; "moderatesevere AD, low comorbidity", 35%; "mild AD, low comorbidity", 20%; "mild AD, respiratory comorbidity", 32%; "mild AD, food-induced comorbidity", 5%) and 4 AD phenotypes in schoolchildren ("moderate-severe AD, high comorbidity", 24%; "moderate-severe AD, low comorbidity", 10%; "mild AD, low comorbidity", 16%; "mild AD, respiratory comorbidity", 49%). Parental history of asthma and eczema, early day-care attendance, and exposure to molds were significantly associated with the "moderate-severe AD, high comorbidity" phenotype in preschool children (P<.05). The "moderate-severe AD" phenotypes were also associated with the highest burden in terms of medication use and limitations in daily activities.

CONCLUSIONS

The detection of different AD phenotypes highlights the need for a stratified approach to the management of this complex disease and for further studies to predict the course of AD and to develop more efficient therapeutic strategies.

Constraining the p-Mode-g-Mode Tidal Instability with GW170817

We analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy from the orbit of the binary to internal modes of the stars, accelerating the gravitational-wave driven inspiral. We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: an overall amplitude, a saturation frequency, and a spectral index. Incorporating these additional parameters, we compute the Bayes factor (lnB_{!pg}^{pg}) comparing our p-g model to a standard one. We find that the observed signal is consistent with waveform models that neglect p-g effects, with lnB_{!pg}^{pg}=0.03_{-0.58}^{+0.70} (maximum a posteriori and 90% credible region). By injecting simulated signals that do not include p-g effects and recovering them with the p-g model, we show that there is a ≃50% probability of obtaining similar lnB_{!pg}^{pg} even when p-g effects are absent. We find that the p-g amplitude for 1.4  M_{⊙} neutron stars is constrained to less than a few tenths of the theoretical maximum, with maxima a posteriori near one-tenth this maximum and p-g saturation frequency ∼70  Hz. This suggests that there are less than a few hundred excited modes, assuming they all saturate by wave breaking. For comparison, theoretical upper bounds suggest ≲10^{3} modes saturate by wave breaking. Thus, the measured constraints only rule out extreme values of the p-g parameters. They also imply that the instability dissipates ≲10^{51}  erg over the entire inspiral, i.e., less than a few percent of the energy radiated as gravitational waves.

Lessons learned from 227 biological meshes used for the surgical treatment of ventral abdominal defects

PURPOSE

The advantages of biological meshes for ventral hernia repair are still under debate. Given the high financial cost, the proper indications for biological meshes should be clarified to restrict their use to properly selected patients.

METHODS

A retrospective database was instituted to register all cases of abdominal wall defect treated with biological meshes from 1/2010 to 3/2016.

RESULTS

A total of 227 patients (mean age: 64 years) whose ventral abdominal defects were reconstructed with a biological mesh were included in the study. Patients were divided according to the 2010 four-level surgical-site complication risk grading system proposed by the Ventral Hernia Working Group (VHWG): Grade 1 (G1, 12 cases), Grade 2 (G2, 68 cases), Grade 3 (G3, 112 cases), and Grade 4 (G4, 35 cases). The surgical site complication rate was higher in patients with one or more risk factors (33.6% vs 19% in patients with no risk factors) (P = 0.68). Statistically significant risk factors associated with the onset of one or more postoperative surgical site complications included: diabetes, coronary artery disease, immunosuppression, and obesity. Recurrence was more common in patients with surgical site complications and mainly associated with infection (38.9%) and wound necrosis (44.4%), and in cases of inlay positioning of the mesh (36%).

CONCLUSIONS

Due to their high costs, biological mesh should not be used in G1 patients. In infected fields (G4), they should only be used if no other surgical solution is feasible. There is a clear need to prospectively evaluate the performance of biological meshes.

A High-throughput Screening of a Chemical Compound Library in Ovarian Cancer Stem Cells

BACKGROUND

Epithelial ovarian cancer has a poor prognosis, mostly due to its late diagnosis and the development of drug resistance after a first platinum-based regimen. The presence of a specific population of "cancer stem cells" could be responsible of the relapse of the tumor and the development of resistance to therapy. For this reason, it would be important to specifically target this subpopulation of tumor cells in order to increase the response to therapy.

METHOD

We screened a chemical compound library assembled during the COST CM1106 action to search for compound classes active in targeting ovarian stem cells. We here report the results of the high-throughput screening assay in two ovarian cancer stem cells and the differentiated cells derived from them.

RESULTS AND CONCLUSION

Interestingly, there were compounds active only on stem cells, only on differentiated cells, and compounds active on both cell populations. Even if these data need to be validated in ad hoc dose response cytotoxic experiments, the ongoing analysis of the compound structures will open up to mechanistic drug studies to select compounds able to improve the prognosis of ovarian cancer patients.

Search for Subsolar-Mass Ultracompact Binaries in Advanced LIGO's First Observing Run

We present the first Advanced LIGO and Advanced Virgo search for ultracompact binary systems with component masses between 0.2  M_{⊙}-1.0  M_{⊙} using data taken between September 12, 2015 and January 19, 2016. We find no viable gravitational wave candidates. Our null result constrains the coalescence rate of monochromatic (delta function) distributions of nonspinning (0.2  M_{⊙}, 0.2  M_{⊙}) ultracompact binaries to be less than 1.0×10^{6}  Gpc^{-3}  yr^{-1} and the coalescence rate of a similar distribution of (1.0  M_{⊙}, 1.0  M_{⊙}) ultracompact binaries to be less than 1.9×10^{4}  Gpc^{-3}  yr^{-1} (at 90% confidence). Neither black holes nor neutron stars are expected to form below ∼1  M_{⊙} through conventional stellar evolution, though it has been proposed that similarly low mass black holes could be formed primordially through density fluctuations in the early Universe and contribute to the dark matter density. The interpretation of our constraints in the primordial black hole dark matter paradigm is highly model dependent; however, under a particular primordial black hole binary formation scenario we constrain monochromatic primordial black hole populations of 0.2  M_{⊙} to be less than 33% of the total dark matter density and monochromatic populations of 1.0  M_{⊙} to be less than 5% of the dark matter density. The latter strengthens the presently placed bounds from microlensing surveys of massive compact halo objects (MACHOs) provided by the MACHO and EROS Collaborations.

GW170817: Measurements of Neutron Star Radii and Equation of State

On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were neutron stars that are described by the same equation of state and have spins within the range observed in Galactic binary neutron stars. Our analysis employs two methods: the use of equation-of-state-insensitive relations between various macroscopic properties of the neutron stars and the use of an efficient parametrization of the defining function p(ρ) of the equation of state itself. From the LIGO and Virgo data alone and the first method, we measure the two neutron star radii as R_{1}=10.8_{-1.7}^{+2.0}  km for the heavier star and R_{2}=10.7_{-1.5}^{+2.1}  km for the lighter star at the 90% credible level. If we additionally require that the equation of state supports neutron stars with masses larger than 1.97  M_{⊙} as required from electromagnetic observations and employ the equation-of-state parametrization, we further constrain R_{1}=11.9_{-1.4}^{+1.4}  km and R_{2}=11.9_{-1.4}^{+1.4}  km at the 90% credible level. Finally, we obtain constraints on p(ρ) at supranuclear densities, with pressure at twice nuclear saturation density measured at 3.5_{-1.7}^{+2.7}×10^{34}  dyn cm^{-2} at the 90% level.

Status of Advanced Virgo

The LIGO and the Virgo collaborations have recently announced the first detections of Gravitational Waves. Due to their weak amplitude, Gravitational Waves are expected to produce a very small effect on free-falling masses, which undergo a displacement of the order of 10-18 m for a Km-scale mutual distance. This discovery showed that interferometric detectors are suitable to reveal such a feeble effect, and therefore represent a new tool for astronomy, astrophysics and cosmology in the understanding of the Universe. To better reconstruct the position of the Gravitational Wave source and increase the signal-to-noise ratio of the events by means of multiple coincidence, a network of detectors is necessary. In the USA, the LIGO project has recently concluded its second Observation Run (O2) with a couple of twin 4 kilometer-long arms detectors which are placed in Washington State and Louisiana. Advanced VIRGO (AdV) is a 3 kilometer-long arms second generation interferometer situated in Cascina, near Pisa in Italy. The installation of AdV has been completed in 2016, and the first commissioning phase allowed to get to the target early-stage sensitivity, which was sufficient to join LIGO in the O2 scientific run. In this paper, the challenges of the commissioning of AdV will be presented, together with its current performances and future perspectives. Finally, in the last paragraph the latest discoveries that occurred after the ICNFP 2017 conference will be also described.