Evaluation of ATTR-cardiac amyloidosis employing Tc-99m pyrophosphate scintigraphy using planar, SPECT and gated SPECT imaging on dedicated cardiac CZT camera

Background/Introduction

Recent recognition that ATTR cardiac amyloidosis (ATTR-CA) is not uncommon and the emergence of novel therapeutic opportunities resulted in the publication of “Expert Consensus Recommendations for Multimodality Imaging in Cardiac Amyloidosis”. However, almost all data were derived from general purpose NaI cameras, while new cardiac dedicated CZT cameras are becoming more widespread.

Purpose

To evaluate Tc-99m pyrophosphate (PYP) scintigraphy on D-SPECT cardio dedicated CZT camera (Spectrum Dynamics) in suspected ATTR-CA patients.

Methods

Seventy three consecutive patients suspected for ATTR-CA underwent planar (5 min), SPECT and gated SPECT (10 min, 8 bins) scintigraphy 89±26 min after injection of Tc99m-PYP 740 MBq, followed by late scintigraphy after 92±36 min in 65 consecutive patients. Perguini visual score, planar H/CL and SPECT derived H/CL ratio were evaluated by two blinded independent experienced readers. Diagnosis was based on visual interpretation after blood pool and monoclonal gammopathy were excluded.

Results

Very good to excellent planar and SPECT image quality was observed in almost all patients. PYP scintigraphy was positive in 6/73 patients, with left ventricular wall uptake clearly evident in the planar images of most patients. There was perfect agreement between readers regarding positive/negative interpretation. There was also substantial inter-observer agreement regarding the Perguini scoring (Cohen's k with linear weighting 0.819, 95% CI 0.701–0.937). Inter-observer agreement for H/CL ratio was also good (Pearson's correlation coefficient r(71)=0.873). SPECT and gated SPECT images were helpful only in one positive patient, and did not have an added value in any of the negative studies. Slightly better images were observed during late scintigraphy, but there was no change in interpretation, and H/CL ratio was not significantly changed (median difference −0.01, IQR 0.09). Alas, Inter-observer agreement of H/CL ratio was lower (Pearson's correlation coefficient r(64)=0.633). We also evaluated H/CL ratio derived from SPECT based application of the camera manufacturer. Agreement between early planar and early SPECT based H/CL ratio was good for both readers (r(69)=0.778 and r(66)=0.747), but inter-observer agreement was lower (r(66)=0.697).

Conclusions

ATTR PYP scintigraphy using cardiac dedicated CZT camera yielded excellent images in almost all patients, and uptake in the left ventricular wall could be easily identified in positive patients. Inter-observer agreement was excellent for both visual scoring and planar H/CL ratio. Early planar images were high quality, and limited additional diagnostic value was observed for both SPECT and gated SPECT scintigraphy and from later acquisition.

Funding Acknowledgement

Type of funding source: None

Prehabilitation in elective abdominal cancer surgery in older patients: systematic review and meta-analysis

BACKGROUND

Prehabilitation has emerged as a strategy to prepare patients for elective abdominal cancer surgery with documented improvements in postoperative outcomes. The aim of this study was to assess the evidence for prehabilitation interventions of relevance to the older adult.

METHODS

Systematic searches were conducted using MEDLINE, Web of Science, Scopus, CINAHL and PsychINFO. Studies of preoperative intervention (prehabilitation) in patients undergoing abdominal cancer surgery reporting postoperative outcomes were included. Age limits were not set as preliminary searches revealed this would be too restrictive. Articles were screened and selected based on PRISMA guidelines, and assessment of bias was performed. Qualitative, quantitative and meta-analyses of data were conducted as appropriate.

RESULTS

Thirty-three studies (3962 patients) were included. Interventions included exercise, nutrition, psychological input, comprehensive geriatric assessment and optimization, smoking cessation and multimodal (two or more interventions). Nine studies purposely selected high-risk, frail or older patients. Thirty studies were at moderate or high risk of bias. Ten studies individually reported benefits in complication rates, with meta-analyses for overall complications demonstrating significant benefit: multimodal (risk difference -0·1 (95 per cent c.i. -0·18 to -0·02); P = 0·01, I2  = 18 per cent) and nutrition (risk difference -0·18 (-0·26 to -0·10); P < 0·001, I2  = 0 per cent). Seven studies reported reductions in length of hospital stay, with no differences on meta-analysis.

CONCLUSION

The conclusions of this review are limited by the quality of the included studies, and the heterogeneity of interventions and outcome measures reported. Exercise, nutritional and multimodal prehabilitation may reduce morbidity after abdominal surgery, but data specific to older patients are sparse.

GW190521: A Binary Black Hole Merger with a Total Mass of 150 M_{⊙}

On May 21, 2019 at 03:02:29 UTC Advanced LIGO and Advanced Virgo observed a short duration gravitational-wave signal, GW190521, with a three-detector network signal-to-noise ratio of 14.7, and an estimated false-alarm rate of 1 in 4900 yr using a search sensitive to generic transients. If GW190521 is from a quasicircular binary inspiral, then the detected signal is consistent with the merger of two black holes with masses of 85_{-14}^{+21}  M_{⊙} and 66_{-18}^{+17}  M_{⊙} (90% credible intervals). We infer that the primary black hole mass lies within the gap produced by (pulsational) pair-instability supernova processes, with only a 0.32% probability of being below 65  M_{⊙}. We calculate the mass of the remnant to be 142_{-16}^{+28}  M_{⊙}, which can be considered an intermediate mass black hole (IMBH). The luminosity distance of the source is 5.3_{-2.6}^{+2.4}  Gpc, corresponding to a redshift of 0.82_{-0.34}^{+0.28}. The inferred rate of mergers similar to GW190521 is 0.13_{-0.11}^{+0.30}  Gpc^{-3} yr^{-1}.

Prognostic gene expression signature for high-grade serous ovarian cancer

BACKGROUND

Median overall survival (OS) for women with high-grade serous ovarian cancer (HGSOC) is ∼4 years, yet survival varies widely between patients. There are no well-established, gene expression signatures associated with prognosis. The aim of this study was to develop a robust prognostic signature for OS in patients with HGSOC.

PATIENTS AND METHODS

Expression of 513 genes, selected from a meta-analysis of 1455 tumours and other candidates, was measured using NanoString technology from formalin-fixed paraffin-embedded tumour tissue collected from 3769 women with HGSOC from multiple studies. Elastic net regularization for survival analysis was applied to develop a prognostic model for 5-year OS, trained on 2702 tumours from 15 studies and evaluated on an independent set of 1067 tumours from six studies.

RESULTS

Expression levels of 276 genes were associated with OS (false discovery rate < 0.05) in covariate-adjusted single-gene analyses. The top five genes were TAP1, ZFHX4, CXCL9, FBN1 and PTGER3 (P < 0.001). The best performing prognostic signature included 101 genes enriched in pathways with treatment implications. Each gain of one standard deviation in the gene expression score conferred a greater than twofold increase in risk of death [hazard ratio (HR) 2.35, 95% confidence interval (CI) 2.02-2.71; P < 0.001]. Median survival [HR (95% CI)] by gene expression score quintile was 9.5 (8.3 to -), 5.4 (4.6-7.0), 3.8 (3.3-4.6), 3.2 (2.9-3.7) and 2.3 (2.1-2.6) years.

CONCLUSION

The OTTA-SPOT (Ovarian Tumor Tissue Analysis consortium - Stratified Prognosis of Ovarian Tumours) gene expression signature may improve risk stratification in clinical trials by identifying patients who are least likely to achieve 5-year survival. The identified novel genes associated with the outcome may also yield opportunities for the development of targeted therapeutic approaches.

Breast cancer surgery in older women: outcomes of the Bridging Age Gap in Breast Cancer study

Background

Breast cancer surgery in older women is variable and sometimes non-standard owing to concerns about morbidity. Bridging the Age Gap in Breast Cancer is a prospective multicentre cohort study aiming to determine factors influencing treatment selection and outcomes from surgery for older patients with breast cancer.

Methods

Women aged at least 70 years with operable breast cancer were recruited from 57 UK breast units between 2013 and 2018. Associations between patient and tumour characteristics and type of surgery in the breast and axilla were evaluated using univariable and multivariable analyses. Oncological outcomes, adverse events and quality-of-life (QoL) outcomes were monitored for 2 years.

Results

Among 3375 women recruited, surgery was performed in 2816 patients, of whom 24 with inadequate data were excluded. Sixty-two women had bilateral tumours, giving a total of 2854 surgical events. Median age was 76 (range 70–95) years. Breast surgery comprised mastectomy in 1138 and breast-conserving surgery in 1716 procedures. Axillary surgery comprised axillary lymph node dissection in 575 and sentinel node biopsy in 2203; 76 had no axillary surgery. Age, frailty, dementia and co-morbidities were predictors of mastectomy (multivariable odds ratio (OR) for age 1·06, 95 per cent c.i. 1·05 to 1·08). Age, frailty and co-morbidity were significant predictors of no axillary surgery (OR for age 0·91, 0·87 to 0·96). The rate of adverse events was moderate (551 of 2854, 19·3 per cent), with no 30-day mortality. Long-term QoL and functional independence were adversely affected by surgery.

Conclusion

Breast cancer surgery is safe in women aged 70 years or more, with serious adverse events being rare and no mortality. Age, ill health and frailty all influence surgical decision-making. Surgery has a negative impact on QoL and independence, which must be considered when counselling patients about choices.

Patients with diabetes are at higher risk for severe illness from COVID-19

•

It is currently uncertain whether people with diabetes are at higher risk of severe illness from coronavirus disease 2019 (COVID-19).

•

We found that diabetes was associated with an approximately 4-fold increased risk of having severe/critical COVID-19 illness.

•

This association was independent of age, sex, obesity, hypertension and smoking.

•

These findings highlight the urgent need for a multidisciplinary team-based approach to management of this patient population.

Optimizing antibiotic use for early onset sepsis: A tertiary NICU experience

BACKGROUND

Neonatal antibiotic use is associated with a greater risk of nosocomial infection, necrotizing enterocolitis, and mortality. It can induce drug-resistant pathogens that contribute to increased neonatal morbidity/mortality, healthcare costs, and length of stay. Prior to the antibiotic stewardship program, decisions to obtain blood cultures and empiric antibiotics for possible Early-onset Sepsis (EOS) in late preterm and term infants upon NICU admission were provider-dependent rather than algorithm-based. We aimed to decrease empiric antibiotic prescription from 70% to 56% (20% decrease) in infants ≥34 weeks gestation admitted to the NICU.

METHODS

The stewardship initiative comprised the following practice changes: (1) use of the Neonatal Sepsis Risk Calculator (SRC); and (2) a 36-hour time-out for prescribed empiric antibiotics. Data was retrospectively collected and analyzed for inborn infants pre-intervention (January 2015-December 2015; n = 263) and post-intervention (August 2016-September 2017; n = 279). Data regarding compliance with the new antibiotic guideline were collected and disseminated to the team every week. Overlap between CDC guidelines and calculator recommendations were studied.

RESULTS

Pre-and post-intervention outcomes were analyzed using chi-square tests. There was a significant post-intervention reduction in the rate of both antibiotic prescriptions (29.4% decline; 70.3% vs. 49.6%; p < 0.001) and sepsis evaluations (24.3% decline; 90.9% vs. 68.8%; p < 0.001). No difference (p = 0.271) in culture-positive EOS cases was observed. There was 92% overlap in blood culture recommendations and 95% overlap between antibiotic recommendations when current CDC guidelines were compared to the SRC.

CONCLUSION

A significant reduction in antibiotic use and sepsis evaluations was achieved for late preterm and term infants upon NICU admission. No clinical deterioration occurred in post-intervention infants who did not receive antibiotics. There is significant overlap between CDC guidelines and SRC recommendations.

P1510 Assessment of left ventricular relaxation time constant by noninvasive left ventricular pressure-strain loop: invasive validation

Introduction

Left ventricular (LV) relaxation time constant, Tau (τ), is one of the best indexes to evaluate left ventricular diastolic function and is usually assessed invasively. Tau is the time constant of the exponential regression Pt =(P0-P∞)e-t/τ+P∞ that expresses left ventricular isovolumic pressure decay, where Pt is LV pressure (LVP) at time t, P0 is LVP at dP/dtmin and P∞ is the asymptotic pressure, to which relaxation would lead if completed without LV filling. Several noninvasive methods were developed to calculate Tau, however, they are time-consuming and complicated. Recently, a simple method regional left ventricular pressure–strain loops and myocardial work was introduced and validated. We hypothesize that left ventricular relaxation time constant can be derived and calculated from the LV pressure–strain loops.

Objective

To calculate noninvasively Tau using LV pressure–strain loops and compare it to invasive Tau assessment.

Methods

The study includes patients with preserved LV systolic function without significant valvular disease that were scheduled to elective coronary catheterization. During catheterization, a fluid-filled catheter was placed in the LV to measure pressure. Echocardiography was performed simultaneously with LV pressure recording. Three standard apical views were acquired and subsequently 2D strain analysis was performed using commercially available GE software and LV pressure–strain loops were calculated. Doppler signal was used for timing of valvular events. Tau was calculated by the equation τ =P/(-dP/dt) that is a derivative of the ventricular pressure decline P = P0e-t/τ+PB with respect to time. The pressure between peak negative dP/dt and the lowest LV pressure shortly after mitral valve opening was used for this calculation. The study was approved by the institutional ethics committee.

Results

Forty patients, (mean age 65.1 ± 10.9 years, 27 male, BSA1.93 ± 0.18 m2) were included in the study. Heart rate and the mean blood pressure at the time of catheterization were 69.9 ± 11.8 min-1 and 85.2 ± 18.8 mmHg, respectively. The mean LV end diastolic diameter was 44 ± 4 mm, the LV mass was 86.7 ± 25.2 g/m2, LVEF 58.4 ± 6.6% and GLS 21.0 ± 3.2%. Tau, calculated noninvasively using derivative method was significantly lower than invasively derived measurement (40.1 ± 13.4 vs 49.8 ± 7.7 msec, p = 0.002). However, a significant positive correlation was observed between the two methods (r =0.67, p &lt;0.001, Figure).

Conclusions

This preliminary study demonstrates that Tau estimated by a noninvasive method using LV pressure–strain loops has a good correlation with Tau measured invasively. Therefore, Tau can be estimated noninvasively using novel left ventricular pressure–strain loop method.

Abstract P1510 Figure.

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

We present our current best estimate of the plausible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next several years, with the intention of providing information to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals for the third (O3), fourth (O4) and fifth observing (O5) runs, including the planned upgrades of the Advanced LIGO and Advanced Virgo detectors. We study the capability of the network to determine the sky location of the source for gravitational-wave signals from the inspiral of binary systems of compact objects, that is binary neutron star, neutron star-black hole, and binary black hole systems. The ability to localize the sources is given as a sky-area probability, luminosity distance, and comoving volume. The median sky localization area (90% credible region) is expected to be a few hundreds of square degrees for all types of binary systems during O3 with the Advanced LIGO and Virgo (HLV) network. The median sky localization area will improve to a few tens of square degrees during O4 with the Advanced LIGO, Virgo, and KAGRA (HLVK) network. During O3, the median localization volume (90% credible region) is expected to be on the order of 10 5 , 10 6 , 10 7 Mpc 3 for binary neutron star, neutron star-black hole, and binary black hole systems, respectively. The localization volume in O4 is expected to be about a factor two smaller than in O3. We predict a detection count of 1 - 1 + 12 ( 10 - 10 + 52 ) for binary neutron star mergers, of 0 - 0 + 19 ( 1 - 1 + 91 ) for neutron star-black hole mergers, and 17 - 11 + 22 ( 79 - 44 + 89 ) for binary black hole mergers in a one-calendar-year observing run of the HLV network during O3 (HLVK network during O4). We evaluate sensitivity and localization expectations for unmodeled signal searches, including the search for intermediate mass black hole binary mergers.

P2629Early benefits of empagliflozin in patients with type 2 diabetes with heart failure are not offset by increased adverse events: results from the EMPA-REG OUTCOME trial

Background

The cardiovascular (CV) benefits of sodium-glucose co-transporter-2 (SGLT2) inhibitors in patients with type 2 diabetes (T2D) have been demonstrated in long-term clinical trials. In the EMPA-REG OUTCOME trial, the SGLT2 inhibitor empagliflozin (EMPA), compared with placebo (PBO), significantly reduced the risk of CV death and hospitalisation for heart failure (HHF) in patients with T2D and established CV disease, with a median follow-up time of 3.1 years.

Purpose

To investigate the early benefits and safety associated with use of EMPA in patients enrolled in the EMPA-REG OUTCOME trial according to heart failure (HF) status at baseline.

Methods

We evaluated the effects of treatments on glycated haemoglobin (HbA1c) levels and on the clinical endpoints of HHF, HHF or CV death, and HHF or all-cause mortality (ACM), as well as the occurrence of adverse events (AEs), at 12 weeks, 6 months, and 1 year after randomisation. Outcomes data were explored descriptively at 12 weeks, and assessed by Cox regression models adjusting for baseline risk factors at 6 months, and 1 year, whereas safety data were explored descriptively. Effects on HbA1c were evaluated using a Mixed Model Repeated Measures (MMRM) model.

Results

A total of 7020 participants, 706 (10%) with investigator-reported HF at baseline, were randomised to PBO, or two different doses of EMPA (10 mg or 25 mg once daily). In patients with HF at baseline, the adjusted mean differences in HbA1c between pooled EMPA and PBO at 12 weeks, 6 months, and 1 year after randomisation were −0.55, −0.54 and −0.53%-point, respectively, p<0.001 vs PBO for all, with similar results in those without HF (p for interactions 0.822, 0.939 and 0.539 at 12 weeks, 6 months and 1 year, respectively). Already at 12 weeks, patients assigned to EMPA had a lower frequency of all evaluated clinical outcome events (HHF, HHF or CV death, HHF or ACM) compared with PBO, regardless of HF status. This effect was sustained and significant at 6 months and 1 year in those with and without HF (see Figure). During the same time frame, the rates of AEs were generally higher in those with HF than without HF, but were not increased by the use of EMPA. At 1 year, any AE occurred in 206 (84.4%) and 1694 (81.1%) patients with and without HF, respectively, on PBO vs 363 (78.6%) and 3246 (76.8%) patients with and without HF on EMPA; any serious AE at 1 year occurred in 79 (32.4%) and 447 (21.4%) patients with and without HF on PBO vs 105 (22.7%) and 764 (18.1%) of those with and without HF on EMPA.

Conclusions

In the EMPA-REG OUTCOME trial, EMPA led to early beneficial effects on morbidity and mortality outcomes in patients with T2D with or without HF, which were not offset by an increased risk of AEs.

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

We present a search for subsolar mass ultracompact objects in data obtained during Advanced LIGO's second observing run. In contrast to a previous search of Advanced LIGO data from the first observing run, this search includes the effects of component spin on the gravitational waveform. We identify no viable gravitational-wave candidates consistent with subsolar mass ultracompact binaries with at least one component between 0.2  M_{⊙}-1.0  M_{⊙}. We use the null result to constrain the binary merger rate of (0.2  M_{⊙}, 0.2  M_{⊙}) binaries to be less than 3.7×10^{5}  Gpc^{-3} yr^{-1} and the binary merger rate of (1.0  M_{⊙}, 1.0  M_{⊙}) binaries to be less than 5.2×10^{3}  Gpc^{-3} yr^{-1}. Subsolar mass ultracompact objects are not expected to form via known stellar evolution channels, though it has been suggested that primordial density fluctuations or particle dark matter with cooling mechanisms and/or nuclear interactions could form black holes with subsolar masses. Assuming a particular primordial black hole (PBH) formation model, we constrain a population of merging 0.2  M_{⊙} black holes to account for less than 16% of the dark matter density and a population of merging 1.0  M_{⊙} black holes to account for less than 2% of the dark matter density. We discuss how constraints on the merger rate and dark matter fraction may be extended to arbitrary black hole population models that predict subsolar mass binaries.

P1791Conduction abnormalities following aortic valve intervention in patients with transthyretin cardiac amyloidosis

Introduction

Aortic Stenosis (AS) is the most common valvular heart disease in the Western world. Transcatheter aortic valve implantation (TAVI) is an alternative to surgical valve replacement in medium and high-risk patients. One of the most common complications after TAVI is conduction system disturbances including bundle branch block, complete heart block and need for permanent pacemaker implantation. Transthyretin cardiac amyloidosis (TTR–CA) is an increasingly recognized cause of heart failure that almost exclusively affects older adults. Diagnosis of TTR-CA in patients undergoing valvular intervention is relevant to understand their clinical outcomes and to discuss specific management.

Objectives

Occult amyloid may account for the frequent need for pacemakers among TAVR patients. We aimed to assess the correlation between intervention induced conduction abnormalities and the need for a pacemaker insertion and the presence of TTR-CA.

Methods

The study population included patients who had aortic valve intervention between 2011–2018. The patients underwent Tc99m-PYP scan using SPECT technology which has been shown to be valid for the diagnosis of TTR-CA. We examined the rate of conduction disorders and the need for a permanent pacemaker from patient files at the time of hospitalization and during a 24-month follow-up.

Results

The study population included 86 patients, mean age 78±6 years, 55% women. Twenty-nine (33%) of the participants were diagnosed as positive (VAS 2 and 3) for transthyretin cardiac amyloidosis. There were no differences in baseline characteristics with regard to age, gender, risk factors, hemoglobin and renal function between patients positive and negative for TTR CA. Conduction disorders were seen in 35 (40%) patients. Patients with TTR CA had a statistically higher prevalence of conduction disorders. Forty-two percent of TTR CA positive patients underwent peri-procedural permanent pacemaker implantation compared to 28% peri-procedural pacemaker implantations in the negative group (p=0.043). Development of a new left bundle branch block during the follow-up period was observed in 14.1% of all patients. There was a statistically significant higher rate in the positive group compared to TTR CA negative group (39.1% vs 10.9% p=0.03).

Conclusions

We observed a high prevalence of occult TTR-CA in older adults with aortic stenosis who underwent TAVI. We also found a high prevalence of conduction abnormalities following TAVI in patients with TTR CA. These findings suggest a need for more careful observation for possible conduction abnormalities and requirement for pacemaker insertion in these patients.

Acknowledgement/Funding

None

P4494Renal insufficiency mitigates the protective effects of elevated anti endothelial cell antibodies on survival in patients undergoing coronary angiography

Background

We previously demonstrated that elevated levels of antiendothelial cell antibodies are associated with improved survival of patients undergoing coronary angiography. However, renal insufficiency, which is associated with decreased survival, leads to increased level of the antiendothelial cell antibodies. The purpose of this study was to evaluate the correlation of the levels of these antibodies with survival in patients with normal versus reduced renal function.

Patients and methods

This was a single center prospective study. Eight hundred thirty eight consecutive patients undergoing coronary angiography with detectable antibody levels were enrolled. The levels of antiendothelial antibodies were determined by ELISA and measured in optical density units. Renal insufficiency was defined as adjusted GFR<60 ml/min. The mean follow up was 30 months.

Results

Of total 838 patients, 481 (57%) had normal and 357 (42.6%) had reduced renal function. Total mortality was 13.6%, being significantly higher in patients with reduced (23.2%) versus normal (6.4%) renal function (p<0.0001). Antiendothelial cell antibody levels were higher in patients with normal versus reduced renal function (4.76±7.05 versus 3.84±6.09 OD units, p=0.042). Antiendothelial cell antibody levels were significantly higher in survived versus deceased patients (4.56±6.82 versus 3.14±5.50 OD units, p=0.014). This association with survival was even more pronounced in patients with normal renal function (4.98±7.19 versus 11.69±3.29 OD units, p<0.0001). In patients with reduced renal function, there was no significant difference between survived and deceased patients (3.89±6.12 versus 3.68±6.05 OD units, p=0.788).

Conclusions

Renal insufficiency leads to mild decrease in the antiendothelial cell antibodies' levels. Higher levels of antiendothelial cell antibodies are associated with improved survival in patients undergoing coronary angiography. This association is significant in patients with normal but not reduced renal function. Thus, the effect of the higher levels of these antibodies on survival cannot be explained by its association with renal dysfunction.

P911High rate of cardiac amyloidosis in elderly patients with aortic stenosis: clinical presentation before and after aortic valve intervention

Background

Aortic Stenosis (AS) is the most common valvular heart disease in the Western world. Wild-type transthyretin amyloid (wtATTR) affects the heart, causing restrictive cardiomyopathy. Deposits can be found in up to 25% of individuals >85 years of age at autopsy. Recently several reports showed a relatively high prevalence of transthyretin cardiac amyloidosis (TTR-CA) in patients with AS.

Objectives

The aim of this study was to examine the clinical effects of TTR-CA in patients who have undergone aortic valve replacement therapy and evaluate the outcome of the intervention.

Methods

We recruited patients who underwent surgical (AVR) or percutaneous (TAVI) aortic valve intervention between 2011 and 2018. The patients underwent a Tc99m-PYP scan using SPECT technology which has been shown to be valid for the diagnosis of TTR-CA. We reviewed patient files before (time point 1) and after intervention (time point 2) and at 2 years (time point 3) follow up, and collected data on hospitalizations, laboratory, and echocardiography.

Results

The study included 86 patients, mean age 78±6 years, 55% women. Twenty-nine (33%) participants were diagnosed as positive (VAS 2 and 3) for transthyretin cardiac amyloidosis.There were no differences in baseline characteristics between patients with and without TTR-CA in cardiovascular risk factors and co-morbidities, laboratory parameters and nutritional status. There were no differences in baseline echocardiographic parameters including valve gradients and left ventricular hypertrophy. However, the patients with TTR CA had more advanced diastolic dysfunction compared to patients without TTR CA (P=0.03) and higher pulmonary artery pressure (44±14.75mmhg vs 30.5±11.38mmhg, p=0.06). Before the intervention, patients with transthyretin cardiac amyloidosis had 3.26 times more hospitalizations due to heart failure as compared to patients in the negative group (p=0.01).

After the intervention, diastolic function remained more severely affected in the positive group at all follow-up points compared to the negative group (p=0.05). Similar observations were seen in the measurements of pulmonary arterial pressure (p=0.019 at time 2 and p=0.015 at time 3). Consistent with the echocardiographic findings, patients with transthyretin cardiac amyloidosis had 2.84 times more hospitalizations after intervention for heart failure than patients in the negative group (p=0.02).

Conclusions

Co-existence of transthyretin cardiac amyloidosis and aortic stenosis in the older population is associated with a more severe clinical presentation and with more advanced clinical and echocardiographic signs of heart failure. Improvement after valvular intervention might be limited in terms of symptoms and hospitalizations in this subgroup.

Acknowledgement/Funding

None

Health risks from PAHs and potentially toxic elements in street dust of a coal mining area in India

Polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) (Ba, Zn, Pb, Cu, Cr, Ni, As, Co) were determined in the road dusts of a coal mining area (Dhanbad, India) to assess their content and potential human health risks. Dust samples were collected from sign boards of the heavy traffic road connecting Dhanbad and Sindri. The total PAHs (∑PAHs, all values in mg/kg) content in the road dust samples varied from 3.98 to 13.1, with carcinogenic PAHs content of 14.8-34.4% of the ∑PAHs. Phenanthrene (2.72), fluorene (0.715) and pyrene (0.575) are the major PAHs. Principal component analysis revealed that these PAHs are probably originated from pyrogenic (coal combustion and traffic emission) and petrogenic (coal dust, tyre and road particles) sources. Among the PTEs, the mean content was higher for Ba (293 mg/kg) followed by Zn (224), Pb (128), Cu (52.6), Cr (45.2), Ni (22.0), As (17.5) and Co (8.11). The overall pollution load index varied from 0.43 to 1.0. Source analysis showed that PTEs in the road dust of the study site were derived from traffic emission (Zn, Fe, Mn, Co and Pb), coal dust (Cr, As and Ni) and soil (K, Mg, Ba, Sr and Ca). In general, the PTEs are lower, but the PAHs contents were elevated in the road dust samples. Although the exposure risks from PTEs are low, the risk to children (expressed as hazardous quotient) for As and Pb is near to the permissible limit of 1.0. Cancer risk from PAHs for adult (4.8 × 10^-6) and child (5.3 × 10^-6) has exceeded the acceptable limit of 10^-6.

P1487The additive effect of diastolic dysfunction and renal insufficiency on mortality in patients undergoing coronary angiography

Background

Coronary artery disease (CAD) is the leading cause of diastolic dysfunction. Diastolic dysfunction is associated with adverse outcomes. Renal insufficiency is also associated with adverse outcomes in CAD patients. The interaction between diastolic dysfunction and renal insufficiency is not completely elucidated.

Aims

We evaluated the prognostic value of diastolic function assessed by echocardiography in patients with and without renal failure undergoing coronary angiography.

Patients and methods

An observational prospective study of 547 consecutive patients undergoing coronary angiography. The median follow up was 30 months. Significant diastolic dysfunction was defined as elevated LV filling pressure with e/e'>12. Renal insufficiency was defined as adjusted GFR<60 ml/min. One hundred seventy-nine patients (32.7%) had significant diastolic dysfunction and 259 (47.3%) had renal insufficiency. Patients were categorized into 4 groups according to the presence of both significant diastolic dysfunction and renal insufficiency (Table 1).

Results

Significant diastolic dysfunction and renal insufficiency had additive effect on mortality (Table 1). A significant association was observed between diastolic dysfunction and mortality in patients with and without renal insufficiency (p<0.0001 & p=0.005, respectively). The presence of either diastolic dysfunction or renal insufficiency was associated with mortality (Figure 1), with the combination of both leading to the highest mortality (p<0.0001). In Cox regression model which combined diastolic dysfunction, presence of AF, LVEF, obstructive coronary disease on angiography, presence of acute coronary syndrome and renal insufficiency, both elevated filling pressure and renal insufficiency were independently associated with higher mortality (HR 2.65, CI 1.65–4.24, p<0.001 and HR 2.92, CI 1.72–4.98, p<0.0001, respectively).

Table 1. Patients divided into 4 groups according to the presence of the significant diastolic dysfunction and renal insufficiency Patients' group N (%) Mortality Normal LV filling pressure / Normal renal function 230 (42.0%) 4.8% Elevated LV filling pressure / Normal renal function 58 (10.6%) 15.5% Normal LV filling pressure / Renal insufficiency 138 (25.2%) 15.9% Elevated LV filling pressure / Renal insufficiency 121 (22.1%) 38.8% P<0.0001 in Pearson Chi-Square.

Fugure 1

Conclusions

In patients undergoing coronary angiography, significant diastolic dysfunction with elevated filling pressure is associated with mortality in patients both with and without renal insufficiency. Both significant diastolic dysfunction and renal insufficiency are independent predictors of mortality.

P4632Impact of intracardiac thrombosis in patients with acute myocardial infarction: insights from nationwide inpatient sample in the United States

Background

Intracardiac thrombosis (ICT) is a complication of Acute myocardial infarction (AMI).

Hypothesis

Our aim was to evaluate the impact of ICT on mortality, thromboembolism, length of stay in patients with AMI.

Methods

Data was collected from the Nationwide Inpatient Sample (NIS) for the year 2016, where patients with a primary diagnosis of ICT as a complication of AMI (ICD10-CM code I23.6) were included. Comparisons were made between patients with ICT post-AMI (ICD10-CM code I23.6) vs those with AMI (ICD10-CM I21.0).

Results

Of a total of 200930 cases of AMI, 488 (0.5%) had ICT. The patients with ICT had an increased length of stay (LOS) (8.5±9.8 vs 5.7±7.4 days; p<0.001), increased ischemic stroke (10.6% vs 2.9%; p<0.001), and cardiogenic shock (15% vs 7%; p<0.001). There was no difference in mortality between the groups.

Table 1. Patient characteristics AMI% (n=200,930) ICT post AMI% (n=488) p-values Demographic variables   a. Males 59 73   b. Females 41 27 <0.001 Race   a. Caucasian 71 68 0.10   b. African American 11 15 0.01   c. Hispanic 7.5 6.1 0.23   d. Other races 5.6 6.2 0.80   e. Race not specified 4.4 4.9 0.59 Comorbidities   Drug abuse 23.9 31.1 <0.001   Atrial Arrhythmias 33.1 41.6 <0.001   Ventricular Arrhythmias 5.6 9.2 <0.001   Chronic pulmonary disease 27.7 21.1 <0.001   Diabetes Mellitus 38.9 31.1 <0.001   Hypertension 81.2 70.2 <0.001   Peripheral Vascular disease 10.5 3.52 <0.001   Current or past smoker 20.5 26.1 <0.001   Chronic kidney disease 28.1 20.4 <0.001   History of coronary artery bypass surgery 10.6 5.9 <0.001   HFrEF 23.3 50 <0.001 HFrEF = Heart failure with reduced ejection fraction; pVAD = Percutaneous ventricular assist device.

Conclusion

ICT as a complication of AMI is associated with increased hospital LOS and adverse events.

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.

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.

Tilting a ground-state reactivity landscape by vibrational strong coupling

Many chemical methods have been developed to favor a particular product in transformations of compounds that have two or more reactive sites. We explored a different approach to site selectivity using vibrational strong coupling (VSC) between a reactant and the vacuum field of a microfluidic optical cavity. Specifically, we studied the reactivity of a compound bearing two possible silyl bond cleavage sites—Si–C and Si–O, respectively—as a function of VSC of three distinct vibrational modes in the dark. The results show that VSC can indeed tilt the reactivity landscape to favor one product over the other. Thermodynamic parameters reveal the presence of a large activation barrier and substantial changes to the activation entropy, confirming the modified chemical landscape under strong coupling.

Marie M, Stickney K, VanBuecken D, Vellek B, Webber C, Allen L, Bollyk J, Hilderman N, Ismail H, Lamola S, Sanda S, Vendettuoli H, Tridgell D, Monzavi R, Bock M, Fisher L, Halvorson M, Jeandron D, Kim M, Wood J, Geffner M, Kaufman F, Parkman R, Salazar C, Goland R, Clynes R, Cook S, Freeby M, Pat Gallagher M, Gandica R, Greenberg E, Kurland A, Pollak S, Wolk A, Chan M, Koplimae L, Levine E, Smith K, Trast J, DiMeglio L, Blum J, Evans-Molina C, Hufferd R, Jagielo B, Kruse C, Patrick V, Rigby M, Spall M, Swinney K, Terrell J, Christner L, Ford L, Lynch S, Menendez M, Merrill P, Pescovitz M, Rodriguez H, Alleyn C, Baidal D, Fay S, Gaglia J, Resnick B, Szubowicz S, Weir G, Benjamin R, Conboy D, deManbey A, Jackson R, Jalahej H, Orban T, Ricker A, Wolfsdorf J, Zhang HH, Wilson D, Aye T, Baker B, Barahona K, Buckingham B, Esrey K, Esrey T, Fathman G, Snyder R, Aneja B, Chatav M, Espinoza O, Frank E, Liu J, Perry J, Pyle R, Rigby A, Riley K, Soto A, Gitelman S, Adi S, Anderson M, Berhel A, Breen K, Fraser K, Gerard-Gonzalez A, Jossan P, Lustig R, Moassesfar S, Mugg A, Ng D, Prahalod P, Rangel-Lugo M, Sanda S, Tarkoff J, Torok C, Wesch R, Aslan I, Buchanan J, Cordier J, Hamilton C, Hawkins L, Ho T, Jain A, Ko K, Lee T, Phelps S, Rosenthal S, Sahakitrungruang T, Stehl L, Taylor L, Wertz M, Wong J, Philipson L, Briars R, Devine N, Littlejohn E, Grant T, Gottlieb P, Klingensmith G, Steck A, Alkanani A, Bautista K, Bedoy R, Blau A, Burke B, Cory L, Dang M, Fitzgerald-Miller L, Fouts A, Gage V, Garg S, Gesauldo P, Gutin R, Hayes C, Hoffman M, Ketchum K, Logsden-Sackett N, Maahs D, Messer L, Meyers L, Michels A, Peacock S, Rewers M, Rodriguez P, Sepulbeda F, Sippl R, Steck A, Taki I, Tran BK, Tran T, Wadwa RP, Zeitler P, Barker J, Barry S, Birks L, Bomsburger L, Bookert T, Briggs L, Burdick P, Cabrera R, Chase P, Cobry E, Conley A, Cook G, Daniels J, DiDomenico D, Eckert J, Ehler A, Eisenbarth G, Fain P, Fiallo-Scharer R, Frank N, Goettle H, Haarhues M, Harris S, Horton L, Hutton J, Jeffrrey J, Jenison R, Jones K, Kastelic W, King MA, Lehr D, Lungaro J, Mason K, Maurer H, Nguyen L, Proto A, Realsen J, Schmitt K, Schwartz M, Skovgaard S, Smith J, Vanderwel B, Voelmle M, Wagner R, Wallace A, Walravens P, Weiner L, Westerhoff B, Westfall E, Widmer K, Wright H, Schatz D, Abraham A, Atkinson M, Cintron M, Clare-Salzler M, Ferguson J, Haller M, Hosford J, Mancini D, Rohrs H, Silverstein J, Thomas J, Winter W, Cole G, Cook R, Coy R, Hicks E, Lewis N, Marks J, Pugliese A, Blaschke C, Matheson D, Pugliese A, Sanders-Branca N, Ray Arce LA, Cisneros M, Sabbag S, Moran A, Gibson C, Fife B, Hering B, Kwong C, Leschyshyn J, Nathan B, Pappenfus B, Street A, Boes MA, Peterson Eck S, Finney L, Albright Fischer T, Martin A, Jacqueline Muzamhindo C, Rhodes M, Smith J, Wagner J, Wood B, Becker D, Delallo K, Diaz A, Elnyczky B, Libman I, Pasek B, Riley K, Trucco M, Copemen B, Gwynn D, Toledo F, Rodriguez H, Bollepalli S, Diamond F, Eyth E, Henson D, Lenz A, Shulman D, Raskin P, Adhikari S, Dickson B, Dunnigan E, Lingvay I, Pruneda L, Ramos-Roman M, Raskin P, Rhee C, Richard J, Siegelman M, Sturges D, Sumpter K, White P, Alford M, Arthur J, Aviles-Santa ML, Cordova E, Davis R, Fernandez S, Fordan S, Hardin T, Jacobs A, Kaloyanova P, Lukacova-Zib I, Mirfakhraee S, Mohan A, Noto H, Smith O, Torres N, Wherrett D, Balmer D, Eisel L, Kovalakovska R, Mehan M, Sultan F, Ahenkorah B, Cevallos J, Razack N, Jo Ricci M, Rhode A, Srikandarajah M, Steger R, Russell WE, Black M, Brendle F, Brown A, Moore D, Pittel E, Robertson A, Shannon A, Thomas JW, Herold K, Feldman L, Sherwin R, Tamborlane W, Weinzimer S, Toppari J, Kallio T, Kärkkäinen M, Mäntymäki E, Niininen T, Nurmi B, Rajala P, Romo M, Suomenrinne S, Näntö-Salonen K, Simell O, Simell T, Bosi E, Battaglia M, Bianconi E, Bonfanti R, Grogan P, Laurenzi A, Martinenghi S, Meschi F, Pastore M, Falqui L, Teresa Muscato M, Viscardi M, Bingley P, Castleden H, Farthing N, Loud S, Matthews C, McGhee J, Morgan A, Pollitt J, Elliot-Jones R, Wheaton C, Knip M, Siljander H, Suomalainen H, Colman P, Healy F, Mesfin S, Redl L, Wentworth J, Willis J, Farley M, Harrison L, Perry C, Williams F, Mayo A, Paxton J, Thompson V, Volin L, Fenton C, Carr L, Lemon E, Swank M, Luidens M, Salgam M, Sharma V, Schade D, King C, Carano R, Heiden J, Means N, Holman L, Thomas I, Madrigal D, Muth T, Martin C, Plunkett C, Ramm C, Auchus R, Lane W, Avots E, Buford M, Hale C, Hoyle J, Lane B, Muir A, Shuler S, Raviele N, Ivie E, Jenkins M, Lindsley K, Hansen I, Fadoju D, Felner E, Bode B, Hosey R, Sax J, Jefferies C, Mannering S, Prentis R, She J, Stachura M, Hopkins D, Williams J, Steed L, Asatapova E, Nunez S, Knight S, Dixon P, Ching J, Donner T, Longnecker S, Abel K, Arcara K, Blackman S, Clark L, Cooke D, Plotnick L, Levin P, Bromberger L, Klein K, Sadurska K, Allen C, Michaud D, Snodgrass H, Burghen G, Chatha S, Clark C, Silverberg J, Wittmer C, Gardner J, LeBoeuf C, Bell P, McGlore O, Tennet H, Alba N, Carroll M, Baert L, Beaton H, Cordell E, Haynes A, Reed C, Lichter K, McCarthy P, McCarthy S, Monchamp T, Roach J, Manies S, Gunville F, Marosok L, Nelson T, Ackerman K, Rudolph J, Stewart M, McCormick K, May S, Falls T, Barrett T, Dale K, Makusha L, McTernana C, Penny-Thomas K, Sullivan K, Narendran P, Robbie J, Smith D, Christensen R, Koehler B, Royal C, Arthur T, Houser H, Renaldi J, Watsen S, Wu P, Lyons L, House B, Yu J, Holt H, Nation M, Vickers C, Watling R, Heptulla R, Trast J, Agarwal C, Newell D, Katikaneni R, Gardner C, Del A, Rio A, Logan H, Collier C, Rishton G, Whalley A, Ali S, Ramtoola T, Quattrin L, Mastrandea A, House M, Ecker C, Huang C, Gougeon J, Ho D, Pacuad D, Dunger J, May C, O’Brien C, Acerini B, Salgin A, Thankamony R, Williams J, Buse G, Fuller M, Duclos J, Tricome H, Brown D, Pittard D, Bowlby A, Blue T, Headley S, Bendre K, Lewis K, Sutphin C, Soloranzo J, Puskaric H, Madison M, Rincon M, Carlucci R, Shridharani B, Rusk E, Tessman D, Huffman H, Abrams B, Biederman M, Jones V, Leathers W, Brickman P, Petrie D, Zimmerman J, Howard L, Miller R, Alemzadeh D, Mihailescu R, Melgozza-Walker N, Abdulla C, Boucher-Berry D, Ize-Ludlow R, Levy C, Swenson, Brousell N, Crimmins D, Edler T, Weis C, Schultz D, Rogers D, Latham C, Mawhorter C, Switzer W, Spencer P, Konstantnopoulus S, Broder J, Klein L, Knight L, Szadek G, Welnick B, Thompson R, Hoffman A, Revell J, Cherko K, Carter E, Gilson J, Haines G, Arthur B, Bowen W, Zipf P, Graves R, Lozano D, Seiple K, Spicer A, Chang J, Fregosi J, Harbinson C, Paulson S, Stalters P, Wright D, Zlock A, Freeth J, Victory H, Maheshwari A, Maheshwari T, Holmstrom J, Bueno R, Arguello J, Ahern L, Noreika V, Watson S, Hourse P, Breyer C, Kissel Y, Nicholson M, Pfeifer S, Almazan J, Bajaj M, Quinn K, Funk J, McCance E, Moreno R, Veintimilla A, Wells J, Cook S, Trunnel J, Henske S, Desai K, Frizelis F, Khan R, Sjoberg K, Allen P, Manning G, Hendry B, Taylor S, Jones W, Strader M, Bencomo T, Bailey L, Bedolla C, Roldan C, Moudiotis B, Vaidya C, Anning S, Bunce S, Estcourt E, Folland E, Gordon C, Harrill J, Ireland J, Piper L, Scaife K, Sutton S, Wilkins M, Costelloe J, Palmer L, Casas C, Miller M, Burgard C, Erickson J, Hallanger-Johnson P, Clark W, Taylor A, Lafferty S, Gillett C, Nolan M, Pathak L, Sondrol T, Hjelle S, Hafner J, Kotrba R, Hendrickson A, Cemeroglu T, Symington M, Daniel Y, Appiagyei-Dankah D, Postellon M, Racine L, Kleis K, Barnes S, Godwin H, McCullough K, Shaheen G, Buck L, Noel M, Warren S, Weber S, Parker I, Gillespie B, Nelson C, Frost J, Amrhein E, Moreland A, Hayes J, Peggram J, Aisenberg M, Riordan J, Zasa E, Cummings K, Scott T, Pinto A, Mokashi K, McAssey E, Helden P, Hammond L, Dinning S, Rahman S, Ray C, Dimicri S, Guppy H, Nielsen C, Vogel C, Ariza L, Morales Y, Chang R, Gabbay L, Ambrocio L, Manley R, Nemery W, Charlton P, Smith L, Kerr B, Steindel-Kopp M, Alamaguer D, Liljenquist G, Browning T, Coughenour M, Sulk E, Tsalikan M, Tansey J, Cabbage N. Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

A new tool for validating theoretically derived anisotropic displacement parameters with experiment: directionality of prolate displacement ellipsoids

How well do anisotropic displacement parameters from theory match experiment? The orientation of prolate ellipsoids contributes to the answer!

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.

A STAT4 variant increases liver fibrosis risk in Caucasian patients with chronic hepatitis B

BACKGROUND

Host genetic modifiers of the natural history of chronic hepatitis B (CHB) remain poorly understood. Recently, a genome-wide association study (GWAS)-identified polymorphism in the STAT4 gene that contributes to the risk for hepatocellular carcinoma (HCC) was shown to be associated with the full spectrum of hepatitis B virus (HBV) outcomes in Asian patients. However, the functional mechanisms for this effect are unknown and the role of the variant in modulating HBV disease in Caucasians has not been investigated.

AIMS

To determine whether STAT4 genetic variation is associated with liver injury in Caucasian patients with CHB and to investigate potential mechanisms mediating this effect.

METHODS

STAT4 rs7574865 was genotyped in 1085 subjects (830 with CHB and 255 healthy controls). STAT4 expression in liver, PBMCs and NK cells, STAT4 phosphorylation and secretion of interferon-gamma (IFN-γ) according to STAT4 genetic variation was examined.

RESULTS

STAT4 rs7574865 genotype was independently associated with hepatic inflammation (OR: 1.42, 95% CI: 1.07-2.06, P = 0.02) and advanced fibrosis (OR: 1.83, 95% CI: 1.19-2.83, P = 0.006). The minor allele frequency of rs7574865 was significantly lower than that in healthy controls. rs7574865 GG risk carriers expressed lower levels of STAT4 in liver, PBMCs and in NK cells, while NK cells from patients with the risk genotype had impaired STAT4 phosphorylation following stimulation with IL-12/IL-18 and a reduction in secretion of IFN-γ.

CONCLUSION

Genetic susceptibility to HBV persistence, hepatic inflammation and fibrosis in Caucasians associates with STAT4 rs7574865 variant. Downstream effects on NK cell function through STAT4 phosphorylation-dependent IFN-γ production likely contribute to these effects.