Hydrogen-Induced Formation of Surface Acid Sites on Pt/Al(PO3)3 Enables Remarkably Efficient Hydrogenolysis of C-O Bonds in Alcohols and Ethers

The hydrogenolysis of oxygenates such as alcohols and ethers is central to the biomass valorization and also a valuable transformation in organic synthesis. However, a mild and efficient catalyst system for the hydrogenolysis of a large variety of alcohols and ethers with various functional groups is still underdeveloped. Here, we report an aluminum metaphosphate-supported Pt nanoparticles (Pt/Al(PO3)3) for the hydrogenolysis of a wide variety of primary, secondary, and tertiary alkyl and benzylic alcohols, and dialkyl, aryl alkyl, and diaryl ethers, including biomass-derived furanic compounds, under mild conditions (0.1-1 atm of H2, as low as 70 °C). Mechanistic studies suggested that H2 induces formation of the surface Brønsted acid sites via its cleavage by supported Pt nanoparticles. Accordingly, the high efficiency and the wide applicability of the catalyst system are attributed to the activation and cleavage of C-O bonds by the hydrogen-induced Brønsted acid sites with the assistance of Lewis acidic Al sites on the catalyst surface. The high efficiency of the catalyst implies its potential application in energy-efficient biomass valorization or fine chemical synthesis.

Borylation of Stable C(sp3)-O Bonds of Alkyl Esters over Supported Au Catalysts

We report herein that supported gold catalysts efficiently promote the borylation of stable C(sp3)-O bonds of alkyl esters. The use of a disilane as an electron source and gold nanoparticles as a single-electron transfer catalyst is the key to generating alkyl radicals via the homolysis of stable C(sp3)-O bonds, thereby enabling cross-coupling between bis(pinacolato)diboron and linear and cyclic alkyl esters to afford the diverse alkyl boronates.

The Development of the Regenerable Catalytic System in Selective Catalytic Oxidation of Ammonia with High N2 Selectivity

Supported particulate noble-metal catalysts are widely used in industrial catalytic reactions. However, these metal species, whether in the form of nanoparticles or highly dispersed entities, tend to aggregate during reactions, leading to a reduced activity or selectivity. Addressing the frequent necessity for the replacement of industrial catalysts remains a significant challenge. Herein, we demonstrate the feasibility of the 'regenerable catalytic system' exemplified by selective catalytic oxidation of ammonia (NH3-SCO) employing Ag/Al2O3 catalysts. Results demonstrate that our highly dispersed Ag catalyst (Ag HD) maintains >90% N2 selectivity at 80% NH3 conversion and >80% N2 selectivity at 100% NH3 conversion after enduring 5 cycles of reducible aggregation and oxidative dispersion. Moreover, it consistently upholds over 98% N2 selectivity at 100% NH3 conversion after 10 cycles of Ar treatment. During the aggregation-dispersion process, the Ag HD catalyst intentionally aggregated into Ag nanoparticles (Ag NP) after H2 reduction and exhibited remarkable regenerable capabilities, returning to the Ag HD state after calcination in the air. This structural evolution was characterized through in situ transmission electron microscopy, atomically resolved high-angle annular dark-field scanning transmission electron microscopy, and X-ray absorption spectroscopy, revealing the on-site oxidative dispersion of Ag NP. Additionally, in situ diffuse reflectance infrared Fourier transform spectroscopy provided insights into the exceptional N2 selectivity on Ag HD catalysts, elucidating the critical role of NO+ intermediates. Our findings suggest a sustainable and cost-effective solution for various industry applications.

High-Density Formation of Ir/MoOx Interface through Hybrid Clustering for Chemoselective Nitrostyrene Hydrogenation

To form high-density metal/oxide interfacial active sites, we developed a catalyst preparation method based on hybrid clustering. An iridium-molybdenum (Ir-Mo) hybrid clustering catalyst was prepared by using the hybrid cluster [(IrCp*)4Mo4O16] (Cp* = η5-C5Me5) as the precursor. The Ir-Mo hybrid clustering catalyst selectively reduced the nitro group in the hydrogenation of 4-nitrostyrene, whereas the coimpregnated Ir-Mo catalyst reduced both the nitro and vinyl groups nonselectively. The hybrid clustering catalyst also exhibited high selectivity, even at a high Ir loading (5 wt %), in contrast to Ir/MoO3, which exhibited high selectivity only at low Ir loadings (<0.3 wt %). In situ X-ray absorption spectroscopy analysis revealed that oxygen vacancies were formed at the Ir/MoOx interface in the presence of H2. We concluded that a high-density Ir/MoOx interface contributes to the preferential adsorption of nitro groups on vacant sites, promoting the selective hydrogenation of nitro groups.

Development of advanced photon calibrator for Kamioka gravitational wave detector (KAGRA)

The Kamioka Gravitational wave detector (KAGRA) cryogenic gravitational-wave observatory has commenced joint observations with the worldwide gravitational wave detector network. Precise calibration of the detector response is essential for accurately estimating parameters of gravitational wave sources. A photon calibrator is a crucial calibration tool used in laser interferometer gravitational-wave observatory, Virgo, and KAGRA, and it was utilized in joint observation 3 with GEO600 in Germany in April 2020. In this paper, KAGRA implemented three key enhancements: a high-power laser, a power stabilization system, and remote beam position control. KAGRA employs a 20 W laser divided into two beams that are injected onto the mirror surface. By utilizing a high-power laser, the response of the detector at kHz frequencies can be calibrated. To independently control the power of each laser beam, an optical follower servo was installed for power stabilization. The optical path of the photon calibrator's beam positions was controlled using pico-motors, allowing for the characterization of the detector's rotation response. Additionally, a telephoto camera and quadrant photodetectors were installed to monitor beam positions, and beam position control was implemented to optimize the mirror response. In this paper, we discuss the statistical errors associated with the measurement of relative power noise. We also address systematic errors related to the power calibration model of the photon calibrator and the simulation of elastic deformation effects using finite element analysis. Ultimately, we have successfully reduced the total systematic error from the photon calibrator to 2.0%.

Selective formation of acetate intermediate prolongs robust ethylene removal at 0 °C for 15 days

Efficient ethylene (C₂H₄) removal below room temperatures, especially near 0  °C, is of great importance to suppress that the vegetables and fruits spoil during cold-chain transportation and storage. However, no catalysts have been developed to fulfill the longer-than-2-h C₂H₄ removal at this low temperature effectively. Here we prepare gold-platinum (Au-Pt) nanoalloy catalysts that show robust C₂H₄ (of 50 ppm) removal capacity at 0 °C for 15 days (360 h). We find, by virtue of operando Fourier transformed infrared spectroscopy and online temperature-programmed desorption equipped mass spectrometry, that the Au-Pt nanoalloys favor the formation of acetate from selective C₂H₄ oxidation. And this on-site-formed acetate intermediate would partially cover the catalyst surface at 0 °C, thus exposing active sites to prolong the continuous and effective C₂H₄ removal. We also demonstrate, by heat treatment, that the performance of the used catalysts will be fully recovered for at least two times.

Diverse Alkyl-Silyl Cross-Coupling via Homolysis of Unactivated C(sp3)-O Bonds with the Cooperation of Gold Nanoparticles and Amphoteric Zirconium Oxides

Since C(sp³)-O bonds are a ubiquitous chemical motif in both natural and artificial organic molecules, the universal transformation of C(sp³)-O bonds will be a key technology for achieving carbon neutrality. We report herein that gold nanoparticles supported on amphoteric metal oxides, namely, ZrO₂, efficiently generated alkyl radicals via homolysis of unactivated C(sp³)-O bonds, which consequently promoted C(sp³)-Si bond formation to give diverse organosilicon compounds. A wide array of esters and ethers, which are either commercially available or easily synthesized from alcohols participated in the heterogeneous gold-catalyzed silylation by disilanes to give diverse alkyl-, allyl-, benzyl-, and allenyl silanes in high yields. In addition, this novel reaction technology for C(sp³)-O bond transformation could be applied to the upcycling of polyesters, i.e., the degradation of polyesters and the synthesis of organosilanes were realized concurrently by the unique catalysis of supported gold nanoparticles. Mechanistic studies corroborated the notion that the generation of alkyl radicals is involved in C(sp³)-Si coupling and the cooperation of gold and an acid-base pair on ZrO₂ is responsible for the homolysis of stable C(sp³)-O bonds. The high reusability and air tolerance of the heterogeneous gold catalysts as well as a simple, scalable, and green reaction system enabled the practical synthesis of diverse organosilicon compounds.

Low-temperature selective oxidation of methane to methanol over a platinum oxide

The low-temperature activation of methane is highly important as a reaction that can dissociate the strongest C-H bond and convert it into useful compounds. This study demonstrated that supported platinum oxide was found to activate methane near room temperature and selectively afford methanol in the presence of oxygen.

Direct Air Capture of CO2 Using a Liquid Amine-Solid Carbamic Acid Phase-Separation System Using Diamines Bearing an Aminocyclohexyl Group

The phase separation between a liquid amine and the solid carbamic acid exhibited >99% CO₂ removal efficiency under a 400 ppm CO₂ flow system using diamines bearing an aminocyclohexyl group. Among them, isophorone diamine [IPDA; 3-(aminomethyl)-3,5,5-trimethylcyclohexylamine] exhibited the highest CO₂ removal efficiency. IPDA reacted with CO₂ in a CO₂/IPDA molar ratio of ≥1 even in H₂O as a solvent. The captured CO₂ was completely desorbed at 333 K because the dissolved carbamate ion releases CO₂ at low temperatures. The reusability of IPDA under CO₂ adsorption-and-desorption cycles without degradation, the >99% efficiency kept for 100 h under direct air capture conditions, and the high CO₂ capture rate (201 mmol/h for 1 mol of amine) suggest that the phase separation system using IPDA is robust and durable for practical use.

Gold-catalyzed thioetherification of allyl, benzyl, and propargyl phosphates

Supported gold catalysts showed high activity for thioetherification of various phosphates. The surface of gold nanoparticles supported on ZrO2 served as a source for active cationic Au species.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

High-Density Formation of Metal/Oxide Interfacial Catalytic Active Sites through Hybrid Clustering

We developed a method for preparing catalysts based on hybrid clusters that formed high-density metal/oxide interfacial active sites. A Ru-V hybrid cluster, [{Ru(cym)}₄V₆O₁₉] (cym = p-cymene), was used as a precursor to prepare Ru-V catalysts. Transmission electron microscopy and X-ray absorption spectroscopy (XAS) analyses revealed that composite nanoparticles of Ru and V were formed through hybrid clustering, while conventional coimpregnation of Ru and V afforded separate nanoparticles. The activity of the Ru-V catalysts toward N-alkylation of amines with alcohols depended on the mixing method (hybrid clustering > coimpregnation > physical mixing ≈ pristine Ru). The formation mechanism of the composite nanoparticles from the hybrid cluster was revealed using in situ XAS analysis. Finally, we proposed a simple but efficient catalyst preparation method, based on in situ formation of hybrid cluster precursors combined with a conventional coimpregnation method.

Deposition of highly dispersed gold nanoparticles onto metal phosphates by deposition–precipitation with aqueous ammonia

Deposition–precipitation with aqueous ammonia enabled small gold nanoparticles to be deposited onto a series of metal phosphates with high dispersity and density.

Isotopic 18O/16O substitution study on the direct partial oxidation of CH4 to dimethyl ether over a Pt/Y2O3 catalyst using NO/O2 as an oxidant

Dimethyl ether (DME) is produced by partial oxidation of CH₄ with NO/O₂ on Pt/Y₂O₃. Isotopic oxygen (¹⁸O₂) is used to confirm molecular O₂ as the ultimate oxidant and a kinetic isotope effect for ¹⁸O/¹⁶O is observed.

Real-time observation of the effect of oxygen storage materials on Pd-based three-way catalysts under ideal automobile exhaust conditions: an operando study

The dynamic behavior of Pd species and the CeO2 support of 1 wt% Pd/Al2O3 and Pd/CeO2 catalysts during three-way catalysis was examined in real time with operando multi-probe analysis.

Elevated serum carboxy-terminal telopeptide of type I collagen predicts clinical outcome in patients with acute coronary syndrome who underwent percutaneous coronary intervention

Introduction

Serum carboxy-terminal telopeptide of type I collagen (I-CTP) is a collagen degradation product of type I collagen in the extracellular matrix of the heart, blood vessels, and bone. The serum levels of I-CTP were reportedly a predictive marker for cardiac remodeling after acute myocardial infarction. However, it remains unclear whether I-CTP can predict poor clinical outcome in patient with acute coronary syndrome (ACS).

Purpose

The aim of this study was to investigate the association between serum levels of I-CTP and clinical outcome in patients with ACS.

Methods

Serum levels of I-CTP were measured in 200 patients with ACS who underwent percutaneous coronary intervention (PCI). All patients were prospectively followed during the median follow-up period of 1312 days with the end point of major adverse cardiovascular events (MACE). We divided the patients into tertiles according to serum I-CTP level: low I-CTP group (≤4.4 ng/ml, n=72), middle I-CTP group (4.4–6.4 ng/ml, n=65), and high I-CTP group (≥6.5 ng/ml, n=63).

Results

There were 44 MACE, including 24 all-cause death and 9 rehospitalization due to heart failure. I-CTP was significantly higher in patients with MACE than those without (4.90 [interquartile range (IQR): 3.80–6.38] ng/ml vs. 6.65 [IQR: 5.00–10.08] ng/ml, p&lt;0.001). Kaplan-Meier analysis demonstrated that patients in the highest tertile of I-CTP had the greatest risk of MACE. In a univariate analysis, age, Albumin, estimated glomerular filtration rate (eGFR), low-density lipoprotein cholesterol (LDL-C), brain natriuretic peptide (BNP), high-sensitivity C-reactive protein (hsCRP) and I-CTP were significant predictors of MACE. A multivariate Cox proportional hazard analysis showed that the high I-CTP group had a higher risk for MACE (Hazard ratio [HR] 2.6, p=0.049) compared with the low I-CTP group after adjusting for confounding factors.

Conclusions

I-CTP was significantly associated with MACE, suggesting that I-CTP could be a reliable marker for clinical outcome in patients with ACS who underwent PCI.

Figure 1

Funding Acknowledgement

Type of funding source: None

Impact of percutaneous coronary intervention on short and long-term prognosis of elderly patients with acute myocardial infarction from 2010 to 2017 in Japanese population

Background

Advances in therapies have successfully decreased short-term mortality in patients with acute myocardial infarction (AMI). Although aging population is recently increasing in developed countries, there are few reports about the association between prevalence of percutaneous coronary intervention (PCI) and long-term prognosis in elderly patients with AMI in Japan.

Purpose

The aim of this study was to clarify the prevalence of PCI and the impact of PCI on short and long-term prognosis of elderly patients with AMI.

Methods and results

We investigated the prevalence of PCI and short-term mortality in 4,109 patients with AMI who were registered in Yamagata AMI Registry from 2010 to 2017. Long-term mortality was investigated using data from death certification in July 2019. We divided patients with AMI into three age groups (group 1, &lt;65 years old; group 2, 65–79 years old; and group 3, ≥80 years old). Short-term mortality within 30 days was 6.5%, 12.1%, and 28.6%, respectively. Also, prevalence of PCI was 88.0%, 84.7%, and 62.7%, respectively. Multivariate analysis revealed that age, PCI, and severity of Killip classification were significantly associated with short-term mortality after adjustment for confound factors in group 3. Since the prevalence of PCI in group 3 was the lowest among three groups, the cause of PCI not being executed was investigated in 1,429 patients aged ≥80 years old. Elderly patients who didn't undergo PCI was older, more women, and had higher prevalence of chronic kidney disease, previous stroke, and severe Killip classification. Multivariate analysis revealed that age and Killip III/IV were significantly associated with non-executed PCI after adjustment for confound factors. Next, we investigated impact of PCI on long-term mortality in elderly patients who escaped acute death. Multivariate Cox hazard analysis revealed that PCI was associated with lower mortality after adjustment for confound factors (adjusted hazard ratio 2.47, 95% CI: 1.47–4.06; p=0.0008).

Conclusion

Lower prevalence of PCI and higher short-term mortality were observed in elderly patients with AMI aged ≥80 years old. PCI ameliorated long-term mortality as well as short-term mortality in elderly patients with AMI.

Funding Acknowledgement

Type of funding source: None

Highly active and durable WO3/Al2O3 catalysts for gas-phase dehydration of polyols

Gas-phase glycerol dehydration over WO3/Al2O3 catalysts was investigated. WO3 loading on γ-Al2O3 significantly affected the yield of acrolein and the catalyst with 20 wt% WO3 loading showed the highest activity. The WO3/Al2O3 catalyst with 20 wt% WO3 loading showed higher activity and durability than the other supported WO3 catalysts and zeolites. The number of Brønsted acid sites and mesopores of the WO3/Al2O3 catalyst did not decrease after the reaction, suggesting that glycerol has continuous access to Brønsted acid sites inside the mesopores of WO3/Al2O3, thereby sustaining a high rate of formation of acrolein. Dehydration under O2 flow further increased the durability of the WO3/Al2O3 catalyst, enabling the sustainable formation of acrolein. In addition, the WO3/Al2O3 catalyst with 20 wt% WO3 loading showed high activity for the dehydration of various polyols to afford the corresponding products in high yield.

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.

5950Lymphocyte-to-monocyte ratio could predict adverse clinical outcomes in patients with heart failure with preserved ejection fraction

Background

Heart failure with preserved ejection fraction (HFpEF) is increasing with aging of the population, whereas the mechanisms of HFpEF remain poorly understood. It was reported that systemic inflammation is associated with pathophysiology of HFpEF. Lymphocyte-to-monocyte ratio (LMR) is a marker of systemic inflammation, which predicts clinical outcomes in various cancers. However, the prognostic value of LMR has not yet been elucidated in patients with HFpEF.

Purpose

The aim of this study was to investigate the impact of LMR on clinical outcomes in patients with HFpEF.

Methods and results

We prospectively analyzed 414 consecutive patients with HFpEF. Preserved EF was defined as an EF ≥50%. During a median follow-up period of 740 days, there were 111 major adverse cardiovascular events (MACE). When patients were divided into tertiles according to LMR, Kaplan-Meier analysis demonstrated that the low LMR was associated with the greatest risk for MACE. Multivariate Cox proportional hazard regression analysis showed that the low LMR was significantly associated with MACE after adjustment for confounding factors.

Conclusions

Low LMR could predict poor clinical outcomes in patients with HFpEF. LMR is a feasible marker for predicting MACE in patients with HFpEF.

129Elevated plasma xanthine oxidoreductase activity predicts cardiovascular events in patients with heart failure with preserved ejection fraction

Background

The pathophysiology of heart failure with preserved ejection fraction (HFpEF) remains poorly understood, although reactive oxygen species (ROS) is reportedly involved in underlying mechanisms. Xanthine oxidoreductase (XOR) is the rate-limiting enzyme of purine metabolism that plays an important role in producing uric acid, and also generates the ROS. However, the impact of plasma XOR activity on the clinical outcomes in patients with HFpEF remains unclear.

Purpose

The aim of this study was to assess whether plasma XOR activity predicts cardiovascular events in patients with HFpEF.

Methods and results

We measured plasma XOR activity in 257 patients with HFpEF. The patients were divided into 3 groups based on XOR activity: low XOR group (<33 pmol/h/mL, n=45), normal XOR group (33 - 120 pmol/h/mL, n=160), and high XOR group (≥120 pmol/h/mL, n=52). During a median follow-up period of 809 days, there were 74 major adverse cardiovascular events (MACEs). Kaplan-Meier analysis demonstrated that the patients with high XOR activity were at greatest risk for MACEs. A multivariate Cox proportional hazard regression analysis showed that high XOR activity was significantly associated with MACEs after adjustment for confounding factors. Furthermore, we divided the patients into 4 groups according to the presence of high XOR activity and/or hyperuricemia. Cox multivariate hazard regression analysis revealed that the patients with high XOR activity were associated with cardiovascular events in patients with HFpEF, regardless of whether hyperuricemia was present or not.

Conclusions

Elevated plasma XOR activity is significantly associated with adverse clinical outcomes in patients with HFpEF. Inhibition of XOR could be a potential therapy for HFpEF.

P1626MicroRNA-21 deteriorates left ventricular reverse remodeling by promoting cardiac fibrosis in non-ischemic cardiomyopathy

Background

Left ventricular reverse remodeling (LVRR) contributes to better outcomes in patients with non-ischemic cardiomyopathy (NICM). It is reported that LVRR is associated with progression of cardiac fibrosis. MicroRNAs (miRs) have emerged as powerful regulators of post-transcriptional gene expression. We focused on miR-21, which plays a key role in pathogenesis of fibrosis in multiple organs. The aim of this study was to clarify the effect of miR-21 on cardiac fibrosis and LVRR in patients with NICM.

Methods

We measured plasma miR-21 levels in 16 patients with NICM. LVRR was defined as increased LVEF by ≥10% and decreased LV end-diastolic diameter index by ≥10% from baseline data after optimal medication treatment at 1-year of follow-up. Further, we examined miR-21 expression and its potential role in cardiac fibrosis induced by transverse aortic constriction (TAC) in mice and angiotensin II (Ang II) stimulation in neonatal rat cardiomyocytes (NRCMs).

Results

There were 12 patients without LVRR and 4 patients with LVRR. Plasma miR-21 levels were significantly higher in patients without LVRR compared with those with LVRR. In TAC mice heart, miR-21 levels were significantly increased and programmed cell death 4 (PDCD4), a main target of miR-21, was decreased. In vitro, miR-21 levels were significantly increased and its upstream transcriptional factor, activator protein 1 (AP-1), was activated by Ang II stimulation in NRCMs. After transfection of miR-21 specific inhibitor, PDCD4 levels were upregulated. Furthermore, AP-1 activity, expression of collagen type I, and α-smooth muscle actin levels were significantly decreased after miR-21 inhibition.

Conclusions

These findings suggested that miR-21/PDCD4/AP-1 feedback loop pathway was involved in LVRR in patients with NICM by promoting cardiac fibrosis. MiR-21 can be the therapeutic target in NICM.

P3355Stress-induced left ventricular dyssynchrony predicts future cardiac events in patients with known or suspected coronary artery disease

Background

Prognostic value of stress induced left ventricular (LV) dyssynchrony has not been fully understood.

The aim of this study was to evaluate the possible impact between cardiovascular events and stress induced worsening LV dyssynchrony.

Methods and results

One hundred and eighty consecutive subjects with known or suspected coronary artery disease (CAD) (142 men, mean age 68±12 years) underwent both gated myocardial single photon emission computed tomography (SPECT) with 99mTc-sestamibi or tetrofosmin according to a standard same day stress-rest protocol and coronary angiography or coronary computed tomography. The summed difference score (SDS) was calculated in every subjects. LV ejection fraction (EF) and phase Entropy at after stress and rest were determined by cardioREPO software. We determined %ΔEntropy = (stress Entropy - rest Entropy)/rest Entropy x100, as an indicator of stress-induced LV dyssynchrony. In the study population, the mean SDS was 2.7±3.9 and LVEF was 58±16%, stress and rest Entropy were 0.62±0.15 and 0.57±0.13, respectively.

%ΔEntropy was higher in patients with CAD than in those without CAD (3.3±11.5 vs. 10.2±15.0, respectively). Moreover, there was a strict correlation between the presence of CAD and %ΔEntropy, indicator of stress induced LV dyssynchrony (non-CAD vs. CAD and/or 1 vessel disease vs. multivessel disease: 4.3±12.5 vs. 8.8±15.6 vs. 12.7±14.3, respectively. p<0.05)

We examined all study subjects and they were divided into 2 groups by cut off value of the %ΔEntropy constructed with receiver operating characteristic curve (=15.4). Kaplan-Meier analysis revealed that future cardiovascular event rate was significantly higher in %ΔEntropy >15.4 group (20/57) than in %ΔEntropy <15.4 group (24/123) (Log-rank p<0.01). On the other hand, summed stress score and SDS were no significant differences between 2 groups.

However, SDS was higher in patients with future cardiovascular event than in those without cardiovascular event (4.4±5.4 vs. 2.2±3.2, respectively. p=0.001).

Conclusion

In patients with known or suspected CAD, stress-induced worsening LV dyssynchrony may predict the presence of CAD and future cardiac events.

Acknowledgement/Funding

None

5945Single nucleotide polymorphisms of PAR2 gene is associated with subclinical myocardial damage in the general population

Introduction

The protease activated receptor (PAR) 2 is a G protein-coupled receptor and expressed in cardiomyocytes, vascular cells, and leukocytes. Experimental studies demonstrated that PAR2 signaling is associated with adverse cardiac remodeling, heart failure, vascular inflammation and atherosclerosis. Recently, we and others demonstrated that subclinical myocardial damage is associated with cardiovascular mortality in general population. However, the impact of single nucleotide polymorphisms (SNPs) of PAR2 gene on subclinical myocardial damage in general population is unclear.

Purpose

The aim of this study was to investigate whether SNPs of PAR2 gene is associated with subclinical myocardial damage in general population.

Methods

The present study included 2,926 apparently healthy subjects (aged ≥40) who participated in a community-based health checkup. We investigated 639 SNPs and measured serum heart-type fatty acid binding protein (H-FABP) as markers of subclinical myocardial damage.

Results

We found the association of SNPs rs616235 within a PAR2 gene with subclinical myocardial damage. The homozygous A-allele (AA), heterozygous (AG), and homozygous G-allele (GG) carriers of rs616235 were identified in 2084 (71%), 791 (27%), and 51 (2%) subjects, respectively. The prevalence rates of subclinical myocardial damage were 29% in AA carriers, 23% in AG carriers, and 18% in GG carriers. Multivariate logistic analysis showed that the homozygous (AA) of rs616235 was independently associated with subclinical myocardial damage (odds ratio: 1.330, 95% confidence interval: 1.077–1.641, P=0.0080) after adjustment for conventional cardiovascular risk factors.

Conclusions

Genetic variant of PAR2 gene was independently associated with subclinical myocardial damage in the general population.

P2462Left atrial appendage wall velocity evaluated by transthoracic echocardiography is a feasible parameter for predicting cardiac prognosis in patients with heart failure

Background

It was reported that left atrial (LA) remodeling is occurred in patients with heart failure (HF), and increased LA volume index (LAVI) is a feasible predictor for poor prognosis of HF. It was reported that LA remodeling is associated with LA appendage (LAA) dysfunction. We previously reported that LAA wall motion velocity (LAWV) obtained by transthoracic echocardiography (TTE) can noninvasively evaluate LAA dysfunction. However, it remains to be determined whether LAWV is useful for predicting poor prognosis in patients with HF.

Purpose

We investigated whether LAA dysfunction assessed by LAWV is associated with poor prognosis in patients with HF.

Methods

We performed TTE at discharge in 217 consecutive patients who hospitalized for HF (126 males, 71±13 years) and prospectively followed them up. LAWV was measured using Doppler tissue imaging at the LAA tip from the parasternal short-axis view on TTE imaging.

Results

There were 86 patients with cardiac events including 14 cardiac deaths and 72 rehospitalizations for HF during a median follow-up period of 404 days (interquartile range 168–748 days). LAWV was significantly lower in patients with cardiac events than in those without. LAWV was significantly decreased with advancing left ventricular diastolic dysfunction grade. Kaplan-Meier analysis demonstrated that significantly higher cardiac event rate was observed in patients with low LAWV (log-rank test, P=0.004). Cox multivariate hazard analysis revealed that LAWV was an independent predictor for cardiac events after adjusting for confounding factors (hazard ratio 0.57, 95% confidence interval 0.40–0.82, P<0.05). Further, we categorized the patients into 3 groups based on the median of LAWV and left atrial volume index (LAVI), and Kaplan-Meier analysis showed that patients with both low LAWV and high LAVI had the highest rate of cardiac events among 3 groups (log-rank test, P<0.001; Figure).

Figure 1

Conclusion

LAWV may be a feasible parameter for predicting cardiac prognosis in patients with HF.

P1615HECT-Type Ubiquitin E3 Ligase ITCH attenuates cardiac hypertrophy by suppressing Wnt signaling pathway

Background

The homologous to the E6-AP carboxyl terminus (HECT)–type ubiquitin E3 ligase ITCH is an enzyme that plays an important role in ubiquitin proteasomal protein degradation. Dishevelled proteins (Dvl1, Dvl2 and Dvl3), which are involved in canonical Wnt/β catenin signaling pathway, play a role in cardiac hypertrophy.

Purpose

The aim of this study was to examine whether ITCH interacts with Dvls and prevents cardiac hypertrophy induced by pressure overload.

Methods and results

We confirmed the protein interaction between ITCH and Dvls in cardiomyocytes. Overexpression of ITCH decreased protein expression levels of Dvls, phospho-GSK3β and β-catenin. Conversely, knockdown of ITCH using small interfering RNA augmented canonical Wnt/β catenin signaling pathway. Thoracic transverse aortic constriction (TAC) was performed in transgenic mice with cardiac-specific overexpression of ITCH (ITCH-Tg) and wild-type (WT) mice. The canonical Wnt/β catenin signaling pathway was inhibited and cardiac hypertrophy was attenuated in ITCH-Tg mice compared with WT mice after TAC.

Overexpression of ITCH in cardiomyocytes

Conclusion

We demonstrated that ITCH targets Dvls for ubiquitin-proteasome degradation in cardiomyocytes and ameliorates cardiac hypertrophy by suppressing canonical Wnt/β catenin signaling pathway.