PCSK9 modulates the Wnt/beta-catenin signaling pathway in myocardial ischemia/reperfusion injury

Background

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a protein that affects cholesterol homeostasis. Recent research has found that PCSK9 has various effects on the heart that are unrelated to LDL cholesterol regulation. The Wnt/β-catenin signaling pathway plays a crucial role during heart development, and it is re-activated in response to cardiac injury. Low-density lipoprotein receptor-related proteins 5 (LRP5) act as co-receptors of Wnt ligands and are indispensable for Wnt/β-catenin signal transduction. However, it is not fully elucidated whether other members of the LDLR-superfamily may be targets of PCSK9.

Purpose

This study aimed to determine if LRP5 is a PCSK9 target, study the association between PCSK9 and Wnt/β-catenin signaling, and elucidate its effect on myocardial infarction in patients with ischemic cardiomyopathy.

Methods

The expression of Lrp5, phospho-β-catenin, total β-catenin was evaluated by western blot analysis, and the effects of overexpressed PCSK9 were tested under normoxia, hypoxia, or hypoxia/re-oxygenation (H/R) in mouse cardiomyocytes (HL-1). The transcriptional activity of β-catenin was assessed using the TOP-Flash/FOP-Flash luciferase reporter assay. In addition, the impact on various downstream targets of the Wnt/β-catenin signaling pathway was assessed using a quantitative real-time polymerase chain reaction. To examine whether PCSK9 regulates injury of cardiomyocytes in vivo, we subjected transgenic mice with cardiac-specific overexpression of PCSK9 (PCSK9 TG) and wild-type (WT) mice to either sham surgery or ischemia/reperfusion (I/R) surgery.

Results

Under hypoxic conditions, the Wnt/β-catenin signaling pathway-related genes were downregulated in HL-1 cells, as evidenced by lower Lrp5 and active phospho-β-catenin expression levels (0.5-fold, n=3, p<0.01). After H/R, the Wnt/β-catenin-related genes were recovered (1.5-fold, p<0.01) in the control group but not in the PCSK9 overexpressed group. In the luciferase reporter assay results, PCSK9 overexpression inhibited the recovery of β-catenin transcriptional activity after H/R, in contrast to the control group. Furthermore, mRNA levels of Axin2, Cyclin D1, which are the Wnt/β-catenin signaling downstream pathway targets, were down-regulated under hypoxia and recovered after H/R but did not recover in PCSK9 overexpressed cells. In the mouse I/R model, the overall protein levels of the Wnt/β-catenin signaling-related genes were down-regulated in PCSK9 TG mice compared to WT mice after I/R injury.

Conclusions

These results indicated that the regulation of PCSK9 is closely associated with the Wnt/β-catenin signaling pathway which may play a crucial role in damaged cardiomyocytes. It suggests that the regulation of PCSK9 could be a therapeutic target in patients with ischemic cardiomyopathy.

Funding Acknowledgement

Type of funding sources: None.

Prediction of response to cardiac resynchronization therapy using cardiac magnetic resonance imaging in non-ischemic dilated cardiomyopathy

Background

Cardiac resynchronization therapy (CRT) is a well-established therapy for symptomatic heart failure with reduced ejection fraction, but the response is different for individuals. Although many modalities have been conducted to predict CRT response, cardiac magnetic resonance (CMR) to predict CRT response has still insufficient usefulness.

Purpose

We determine whether the parameters including late gadolinium enhancement (LGE) identified in CMR could act as predictors of CRT response.

Methods

We retrospectively investigated 124 patients with non-ischemic dilated cardiomyopathy who underwent CMR before CRT implantation between Jan 2010 and July 2021 in a single center. CRT response was defined as a decrease in left ventricular end-systolic volume (LVESV) >15% on echocardiography after at least 3 months after CRT implantation.

Results

Among the study population (mean age 65.7±11.2 years, mean EF 25±6.5%, 50% of female), 85 (69%) patients were defined as CRT responder. The CRT responders had more left bundle branch block (LBBB) compared with non-responders [79 (92.9%) vs. 23 (59.0%), p<0.001], but there was a no difference of QRS duration (158.7 vs 165.0ms, p=0.054) between two groups. CMR analysis showed that there were no significant differences in the left ventricular (LV) chamber volume and LV ejection fraction between CRT-responder and non-responder. However, the right ventricular (RV) chamber volume was smaller (RV end-diastolic volume index, 86.3 vs 103.5 ml/m2, p=0.039; RV end-systolic volume index, 49.3 vs 68.5 ml/m2, p=0.013) and the RV ejection fraction (RVEF) was higher (46.9 vs 37.6%, p=0.002) in CRT-responders compared with non-responders. The LGE on CMR was more shown in non-responders than in CRT-responders [33 (84.6%) vs 45 (52.9%), p<0.001]. In CMR parameters, RV dysfunction (RVEF <45%) [Odds ratio (OR), 0.21 (0.05–0.93), p=0.045] and LGE [OR, 0.21 (0.05–0.58), p=0.01] were significantly associated with poor CRT response.

Conclusions

The presence of LGE and RV dysfunction on CMR were associated with poor CRT response in patients with non-ischemic dilated cardiomyopathy. Further investigation with CMR for pre-CRT patients is needed to support these results.

Funding Acknowledgement

Type of funding sources: None.

Genetic analysis of Korean non-ischemic dilated cardiomyopathy using next generation sequencing

Background

Non-ischemic dilated cardiomyopathy (NIDCM) is a genetic disorder that causes heart failure and life-threatening arrhythmia. However, there has been no study about the up-to-date genetic analysis for NIDCM in Korean. Therefore, we performed the genetic analysis of Korean NIDCM patients (pts) using next generation sequencing (NGS).

Methods

We analyzed clinical and echocardiographic data of 203 NIDCM in a single center from July 2017 to May 2020. All pts underwent NGS analysis with customized panel including 369 genes. Genetic variants were classified as pathogenic, likely pathogenic mutations or variants of uncertain significance regarding American College of Medical Genetics guideline.

Results

A total of 203 NIDCM pts (57±15 years old, 32.0% male, LVEF 28%) had NGS analysis. Thirty-seven (18.2%) pts had pathogenic or likely pathogenic mutations. The most prevalent mutated genes were TTN (n=16, 43.2%). TNNT2 (n=6, 16.2%), MYBPC3 (n=6, 16.2%) and MYH7 (n=3, 8.1%) mutated genes were common in the following order. The patients with positive panel mutation had no significant difference in initial LVEF (27% vs. 28%, p=0.216) and prevalence of atrial fibrillation (37.8% vs. 44.6%, p=0.454) compared with patients with negative panel mutation. During the median follow-up period of 40 months, there was no significant difference in composite outcome (all-cause death, heart transplantation, LVAD, heart failure re-admission, fatal arrhythmia) (35.3% vs. 32.2%, p=0.729) or presence of improved EF (≥10 points increase from baseline LVEF, and a second measurement of LVEF >40%) (41.2% vs. 50.0%, p=0.354) between the two groups.

Conclusion

This is the first study of NGS analysis in Korean NIDCM pts. We could find disease-related pathogenic or likely pathogenic mutations in 18.2% NIDCM patients. Further prospective, large study should be warranted to elucidate the effect of genetic mutation in clinical manifestation and prognosis of NIDCM in Korean population.

Funding Acknowledgement

Type of funding sources: None.

In-hospital glycemic variability and all-cause mortality in patients hospitalized with acute heart failure: analysis of the KorAHF registry

Introduction

Glycemic variability (GV) is known to be a poor prognostic marker in various diseases including cardiovascular disease.

Purpose

We investigated the association of GV with all-cause mortality in patients with acute heart failure (HF).

Methods

The Korean Acute Heart Failure registry enrolled patients hospitalized for acute HF from 2011 to 2014. Among survivors of the index hospitalization, we analyzed those who had ≥3 blood glucose measurements before discharge. Patients were divided into two groups based on their coefficient of variation (%CV) as an indicator of GV. We investigated all-cause mortality at 6 month and 1 year after discharge.

Results

The study analyzed 2,617 patients (median age 72 years, 53% male). During the median follow-up period of 11 months, 583 (22%) patients died. Compared to alive patients, patients who died had a significantly higher diabetes prevalence (46% vs. 41%, P=0.035) and higher %CV (31.0% vs. 27.5%, P<0.001). Kaplan-Meier curve analysis revealed that a high GV (%CV >21%) was associated with lower cumulative survival to all-cause death compared with a low GV (%CV ≤21%) (log-rank P<0.001). Multivariate Cox proportional analysis showed that a high GV was associated with an increased risk of 6-month mortality (hazard ratio [HR] 2.02, 95% CI 1.58–2.59, P<0.001) and one-year mortality (HR 1.57, 95% CI 1.29–1.91, P<0.001). The risk of high GV for one-year mortality was significant in non-diabetic patients (HR 1.98, 95% CI 1.55–2.53, P<0.001), but not in diabetic patients (HR 1.24, 95% CI 0.91–1.69, P=0.176; P-for-interaction=0.030).

Conclusion

A high GV (%CV >21%) before discharge was associated with all-cause mortality within 1 year, especially in non-diabetic acute HF patients.

Funding Acknowledgement

Type of funding sources: None.

The association between frailty and physical performance in elderly patients with heart failure

Background

Frailty is known to be an important prognostic indicator in heart failure (HF). The Korean version of the frail scale for Koreans (K-FRAIL) has been developed and verified. The purpose of this study is to analyze the relationship between the K-FRAIL scale and physical performance, including muscular fitness and aerobic capacity in patients with HF.

Methods

This study included 143 HF patients aged over 65 years from a single tertiary hospital. In these subjects, muscular fitness was assessed using the handgrip test and knee extensor strength measurement, and aerobic capacity was assessed by cardiopulmonary exercise test and 6-minute walk test. Frailty status was measured using the K-FRAIL questionnaire and was classified as robust (K-FRAIL scale: 0), prefrail (1–2), and frail (3–5).

Results

Mean age of participants with robust (N=37), prefrail (N=75), and frail (N=31) were 72.5, 73.5, and 76.3 years, respectively. There was no difference in sex and left ventricular ejection fraction (LVEF) among groups, but the estimated glomerular filtration rate (eGFR) was significantly lower as frailty status increased (75.6±17.2 vs. 70.0±20.5 vs. 56.1±23.7 mL/min/1.73 m2; P<0.001). Hand-grip strength and knee extensor muscle strength did not differ among groups. However, peak oxygen consumption (peak VO2; 22.8±5.0 vs. 19.3±4.6 vs. 16.9±4.7 mL/kg/min, P<0.001) and 6-min walk distance (458.4±68.2 vs. 404.5±92.3 vs. 311.2±120.5 m; p<0.001) significantly decreased according to frailty severity. In multivariate regression analysis adjusted for age, sex, haemoglobin, eGFR and LVEF, peak VO2 (β=−0.311; P=0.002) and 6-min walk distance (β=−0.384; P<0.001) showed a significant inverse association with the K-FRAIL scale. With the cut-off value from receiver-operating characteristic curve analysis, peak VO2 (hazard ratio, 5.08; p=0.023) and 6MWT (hazard ratio, 3.99; p=0.020) were independent predictor of frailty according to K-FRAIL scale.

Conclusion

In elderly HF patients, physical performance differs according to frailty status, peak VO2 and 6-min walk distance correlates with the K-FRAIL scale better than muscular fitness.

Funding Acknowledgement

Type of funding sources: None.

Dementia in individuals with severe hypercholesterolemia: Korean nationwide cohort study

Background

Dementia risk and benefit of lipid lowering in individuals with severe hypercholesterolemia has not been well studied. The aim of this study was to evaluate the risk of dementia and effect of lipid lowering in this population using nationwide cohort.

Methods

This study was performed using the National Health Insurance Service database of Korea. Among individuals who took health check-up and were followed-up, 1,584,401 were enrolled and analyzed. Study population were categorized to three groups with severe hypercholesterolemia according to LDL-C levels, >260, 225–259, and 190–224 mg/dL groups, and a control group (<160 mg/dL). Risks of incident dementia (all dementia, Alzheimer's disease, and vascular dementia) were compared. In the subgroup with new statin users, the effect of statins was further analyzed according to post-treatment LDL-C levels (<70, 70–99, 100–129, >130 mg/dL).

Results

In the median follow-up of 6.1 years, all dementia occurred up to 5.41/1000 person-year in the groups with severe hypercholesterolemia. Adjusted hazard ratios (aHRs) of all dementia in the groups ranged from 1.05 to 1.34 (p=0.023) and were dependent of LDL-C categories. Alzheimer's disease developed up to 4.94/1000 person-year and aHRs ranged from 1.04 to 1.38 (p=0.040) with the same pattern to all dementia. Vascular dementia occurred up to 0.59/100 person-year and aHRs ranged from 1.03 to 1.57 without significant difference according to LDL-C categories. In the median follow-up of 6.2 years in new statin users, aHRs were 0.69 to 0.92 for all dementia and 0.74 to 0.92 for Alzheimer's disease, and 0.53 to 1.15 for vascular dementia according to post-treatment LDL-C levels. However, the risk was not significantly related to the levels.

Conclusions

This study newly showed elevated risk of dementia, particularly Alzheimer's disease, in patients with severe hypercholesterolemia. The benefit of active lipid lowering on this neurological disease needs to be proven by further studies.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Korean Society of Lipid and Atherosclerosis; National Research Foundation of Korea

Serial high-sensitivity troponin T concentrations and long-term outcomes in patients with suspected acute coronary syndrome

Background

High-sensitivity troponin assays allow for accurate and rapid rule-in or rule-out of myocardial infarction (MI) among patients with acute-onset chest pain. However, prognostic implications of serial high-sensitivity troponin concentrations are unknown.

Purpose

To determine short- and long-term prognostic implications of high-sensitivity troponin T (hsTnT) concentrations and their changes from baseline, in patients with suspected acute coronary syndrome.

Methods

Retrospective cohort study based on Danish national registries. We identified all patients discharged from the hospital with either MI, unstable angina, suspected MI, or chest pain from January 2012 through December 2019 and merged these individuals with all records of two serial hsTnT measurements obtained ≤7 hours apart during the same hospitalization. The primary outcome was death at days 0–30 and 31–365. Prognostic implications of serial hsTnT were examined in accordance with the 2012 ESC algorithm stratifying patients for normal baseline concentrations and relative changes of 20% and 50% from baseline. In case of a normal baseline concentration, 20% and 50% of the upper reference level (14 ng/l) were used as thresholds instead, i.e., 3 ng/l and 7 ng/l, respectively. Absolute risks were calculated through multivariable logistic regression with average treatment effect modeling (G-formula).

Results

Complete data were available in 28,902 individuals (median age [25th-75th percentile] 65.2 [53.4–75.4] years, 11,632 [40.2%] women). Of these, 11,116 (38.5%) had a final diagnosis of MI, 1518 (5.3%) of unstable angina, and 16,268 (56.3%) of either suspected MI or chest pain. Median baseline hsTnT was 18 ng/l (25th-75th percentile, 10–69), second hsTnT 21 ng/l (25th-75th percentile, 10–248), relative hsTnT change 3.6% (25th-75th percentile, 0–66.7), and time between samples 4.0 hours (25th-75th percentile, 3.2–5.4). Most patients had either two normal hsTnT concentrations (9483, 32.8%) or two elevated hsTnT concentrations (18,235, 63.1%). At 30 days, 796 (2.8%) individuals had died, while an additional 1287 (4.6% of 30-day survivors) died between days 31–365. Baseline hsTnT and the relative hsTnT change both displayed a significant, non-linear association with death and interacted with each other (P<0.001). Tables 1 and 2 show the standardized, absolute risks of death (with 95% confidence intervals) from days 0–30 and from days 31–365, respectively. Patients with two normal hsTnT concentrations had very low mortality rates, irrespective of the magnitude of relative change. Conversely, patients with two elevated hsTnT concentrations consistently had high mortality rates.

Conclusions

This is the first study to assess both short- and long-term outcomes as a function of both baseline hsTnT and its change from first to second measurement. In general, patients with two normal hsTnT concentrations have an excellent prognosis while those with two elevated concentrations require scrutiny.

Funding Acknowledgement

Type of funding sources: None.

Impact of metformin on the all-cause mortality in diabetic patients hospitalized with acute heart failure

Introduction

Although the hypothesis that metformin is beneficial for diabetic patients with heart failure (HF) has been steadily raised, there have been no solid data on the efficacy of metformin in acute HF patients.

Purpose

We investigated the impact of metformin on all-cause mortality in hospitalized acute HF patients with type 2 diabetes.

Methods

The Korean Acute Heart Failure registry enrolled patients hospitalized for acute HF from 2011 to 2014. Among this cohort, we analyzed patients with diabetes. We investigated all-cause mortality at 1 year after discharge. Propensity score matching (1:1 matching) and Cox proportional hazard models were used to assess difference in all-cause mortality.

Results

The study analyzed 1,976 diabetic patients (median age 72 years, mean left ventricular ejection fraction (LVEF) 34%, 54.5% male). Among them, 712 (36%) patients were on metformin. After 1:1 propensity score matching, 1,424 patients (712 metformin users vs. 712 non-users) were analyzed. During the median follow-up period of 11 months, 146 (21%) metformin non-users died and 108 (15%) metformin users died. Kaplan-Meier curves showed a higher all-cause mortality rate in non-users than in metformin users (Log-rank P=0.0025). After adjustment for clinically relevant variables, metformin was associated with lower risk for all-cause mortality (HR 0.713, 95% CI 0.551–0.922, P=0.01). In subgroup analyses, metformin use was significantly associated with a lower all-cause mortality in higher eGFR group (≥60 ml/min/1.73 m2, HR 0.531, 95% CI 0.357–0.790, P=0.002), but not in lower eGFR group (<60 ml/min/1.73 m2, HR 0.905, 95% CI 0.643–1.275, P=0.569, P-for-interaction=0.033). There was no significant interaction of metformin use for all-cause mortality between the subgroups with LVEF ≤40% and LVEF >40% (P-for-interaction=0.906).

Conclusion

Metformin use was associated with a lower risk for 1-year all-cause mortality in diabetic acute HF patients, especially in high eGFR group.

Funding Acknowledgement

Type of funding sources: None.

New ABO intron 1 variant alleles

Unusual and discrepant ABO phenotypes are often due to genetic variants that lead to altered levels or activity of ABO transferases and consequently to altered expression of ABO antigens. This report describes eight genetic alterations found in 15 cases with reduced or undetectable expression of ABO antigens. Forward and reverse ABO grouping was performed by standard gel or tube methods. Adsorption-heat elution and saliva testing for H and A substances followed the AABB technical manual procedures. Genomic DNA extracted from whole blood was PCR-amplified to cover the entire ABO coding sequence, splice junctions, proximal promoter, and intron 1 enhancer. Amplification products were sequenced by next-generation or Sanger dideoxy methods, either directly or after cloning into a bacterial plasmid vector. Eight unreported alleles were found in the 15 cases analyzed. Alleles ABO*A(28+1C) and ABO*A(29-5G) harbor variants that alter the consensus sequence at the intron 1 donor and acceptor splice sites, respectively. The other alleles harbor variants that alter the consensus sequence at transcription factor-binding sites in the intron 1 enhancer: specifically, ABO*A(28+5792T), ABO*A(28+5859A), and ABO*A(28+5860G) at GATA-1 sites; ABO*B(28+5877T) and ABO*B(28+5878G) at a RUNX1 site; and ABO*A(28+5843A) at or near a C/EBP site. Molecular and serologic characterization of ABO alleles can help in their future identification and in the resolution of discrepancies.

Unusual and discrepant ABO phenotypes are often due to genetic variants that lead to altered levels or activity of ABO transferases and consequently to altered expression of ABO antigens. This report describes eight genetic alterations found in 15 cases with reduced or undetectable expression of ABO antigens. Forward and reverse ABO grouping was performed by standard gel or tube methods. Adsorption-heat elution and saliva testing for H and A substances followed the AABB technical manual procedures. Genomic DNA extracted from whole blood was PCR-amplified to cover the entire ABO coding sequence, splice junctions, proximal promoter, and intron 1 enhancer. Amplification products were sequenced by next-generation or Sanger dideoxy methods, either directly or after cloning into a bacterial plasmid vector. Eight unreported alleles were found in the 15 cases analyzed. Alleles ABO*A(28+1C) and ABO*A(29–5G) harbor variants that alter the consensus sequence at the intron 1 donor and acceptor splice sites, respectively. The other alleles harbor variants that alter the consensus sequence at transcription factor–binding sites in the intron 1 enhancer: specifically, ABO*A(28+5792T), ABO*A(28+5859A), and ABO*A(28+5860G) at GATA-1 sites; ABO*B(28+5877T) and ABO*B(28+5878G) at a RUNX1 site; and ABO*A(28+5843A) at or near a C/EBP site. Molecular and serologic characterization of ABO alleles can help in their future identification and in the resolution of discrepancies.

Increasing prevalence of diabetic peripheral angiopathy and complications in hospitalized patients in the United States

Objectives

We aim to assess prevalence of diabetes related peripheral arterial disease and associated outcomes in hospitalized patients in the United States.

Methods

Trends in hospitalizations in diabetic patients with PAD were determined using the 2003–2017 National Inpatient Sample database. Hospital outcomes including diabetic ulcer incidence, amputations, and revascularizations were analyzed.

Results

The analysis included 10,303,673 hospitalizations in diabetic patients with PAD (DMPAD) during the study period. Prevalence of PAD among patients with diabetes increased over time (p<0.001). The prevalence of foot ulcers in diabetics have also increased over time (p<0.001). The incidence of amputations in patients with diabetes showed a decreasing trend with increasing prevalence of revascularizations from 2003 to 2009. Since 2010 however, rising rates of amputations, both minor and major are seen, especially in younger populations (age 18–49). Hospital costs for amputations have increased ($6.6 billion in 2003 vs $ 14.8 billion in 2017) as well as the costs for revascularization (6.1 billion in 2003 vs $13 billion in 2017) during the study period (p<0.001).

Conclusions

In this analysis of patients with DMPAD, an alarming rate of disease prevalence and in-hospital limb outcomes, including costs, are realized in the current era.

Funding Acknowledgement

Type of funding sources: None.

High-Resolution X-ray Photoelectron Spectroscopy of an IrO2(110) Film on Ir(100)

High-resolution X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) were used to characterize IrO₂(110) films on Ir(100) with stoichiometric as well as OH-rich terminations. Core-level Ir 4f and O 1s peaks were identified for the undercoordinated Ir and O atoms and bridging and on-top OH groups at the IrO₂(110) surfaces. Peak assignments were validated by comparison of the core-level shifts determined experimentally with those computed using DFT, quantitative analysis of the concentrations of surface species, and the measured variation of the Ir 4f peak intensities with photoelectron kinetic energy. We show that exposure of the IrO₂(110) surface to O₂ near room temperature produces a large quantity of on-top OH groups because of reaction of background H₂ with the surface. The peak assignments made in this study can serve as a foundation for future experiments designed to utilize XPS to uncover atomic-level details of the surface chemistry of IrO₂(110).

Molecular chemisorption of N2 on IrO2(110)

We investigated adsorption of N₂ on stoichiometric and O-rich IrO₂(110) surfaces using temperature programmed desorption (TPD) experiments and density functional theory (DFT) calculations. TPD shows that N₂ desorbs predominantly from the stoichiometric-IrO₂(110) surface in a well-defined peak at 270 K for N₂ coverages below about 0.5 ML and that a shoulder centered near 235 K develops in the N₂ TPD traces as the coverage approaches saturation, indicating that adsorbed N₂ molecules destabilize at high N₂ coverages. Experiments of N₂ adsorption onto O-rich IrO₂(110) surfaces provide evidence that N₂ adsorbs exclusively on the coordinatively unsaturated Ir atoms (Ir_cus) of the surface and that pre-adsorbed O-atoms ("on-top" oxygen) stabilize adsorbed N₂ molecules, causing the main N₂ TPD peak to shift toward higher temperature with increasing oxygen coverages. Consistent with prior results, our DFT calculations predict that an N₂ molecule preferentially adsorbs into an upright configuration on an Ir_cus atom of the IrO₂(110) surface and achieves a binding energy of about 100 kJ/mol. The computed binding energy agrees well with our experimental estimate of ∼90 kJ/mol for low N₂ coverages on stoichiometric IrO₂(110). The DFT calculations also quantitatively reproduce the observed stabilization of N₂ by co-adsorption on-top O-atoms and predict the destabilization of N₂ on IrO₂(110) as the N₂ adlayer becomes crowded at high coverages.

Total Tear IgE Levels Correlate with Allergenic and Irritating Environmental Exposures in Individuals with Dry Eye

Dry eye (DE) and allergic conjunctivitis may present similarly, and it remains unclear whether some individuals have an underlying allergic component to their DE. To better understand this relationship, we performed a cross-sectional study in 75 individuals with DE symptoms and/or signs. Immunoglobulin E (IgE) levels in tear samples were quantified and home environmental exposures assessed via standardized survey. Tears were collected by Schirmer strip, and total tear IgE levels were quantified using enzyme-linked immunosorbent assay (ELISA). Data were analyzed using descriptive statistics and linear and logistic regressions. The main outcome measures were total tear IgE levels and their association with environmental exposures. The mean age of the subjects was 66.2 ± 7.8 years. Sixty-two individuals had dry eye symptoms (Dry Eye Questionnaire-5 ≥ 6), and 75 had one or more signs of DE. Detectable total tear IgE levels were observed in 76% of subjects, and 17.3% had high levels (>1 ng/mL). Individuals with exposure to pet(s) (odds ratio (OR) 11.5, p = 0.002) and smoke (OR 38.6, p = 0.008) at home were more likely to have high IgE levels compared to those not exposed. Individuals with tears collected during spring or summer were 3.9 times (p = 0.028) more likely to have high IgE compared to those sampled at other times of year. Subjects born in the US were 3.45 times (p = 0.010) more likely to have high IgE compared to individuals born outside the US. To conclude, a majority of individuals with DE symptoms and/or signs had detectable IgE levels in their tears. High tear IgE levels were correlated with allergy season and exposures in the home linked with allergy.

P5731Optimal blood pressure in diabetic hypertensive patients with overt proteinuria

Background

Evidence for the benefit of intensive blood pressure lowering in diabetic nephropathy is not clear at this time. The objective of this study was to demonstrate whether lower mean blood pressure (BP) in treated hypertensive patients with diabetic nephropathy is associated with better prognosis.

Methods

From the National Health Insurance Service (NHIS) Health Examination Database, diabetic hypertensive subjects with proteinuria between 2009 and 2010 were selected and followed-up until 2015 (N=8,663). Mean of the recorded systolic and diastolic BP during follow-up health examinations were stratified into five categories (SBP: <120, 120 to <130, 130 to <140, 140 to <150, and ≥150 mmHg; DBP: <70, 70 to <80, 80 to <90, 90 to <100, and ≥100 mmHg). All-cause death, myocardial infarction (MI), stroke, and renal outcome (progression to end stage renal disease or doubling of serum creatinine) were examined by Cox proportional hazard models with the propensity scores adjusted method.

Results

Compared to SBP of 130 to <140 mmHg, SBP of 120 to <130 mmHg was associated with lower risk of all-cause death (HR=0.78; 95% CI, 0.64–0.95), stroke (HR: 0.65; 95% CI, 0.45–0.94), and renal outcome (HR: 0.81; 95% CI, 0.68–0.97). SBP of <120 mmHg was associated with benefit for renal outcomes (HR: 0.69; 95% CI 0.55–0.88) but not with elevated risk of other outcomes. Compared to DBP of 80 to <90 mmHg, DBP of 70 to <80 mmHg were associated with lower risk of all-cause death (HR: 0.75; 95% CI, 0.64–0.88) but with higher risk of MI (HR: 1.52; 95% CI, 1.05–2.21). DBP of <70 mmHg was associated with reduced risk of all-cause death (HR: 0.79; 95% CI, 0.64–0.98).

Conclusion

In diabetic hypertensive subjects with overt proteinuria, deterioration of renal function decreased with decreasing SBP and the lowest risk of all-cause death and stroke were observed in SBP <130 mmHg. Low DBP was associated with low risk of all-cause death but there was a J curve phenomenon for MI in DBP of 70 to <80 mmHg.

P3555Lower native T1, extracellular volume and T2 on cardiac magnetic resonance imaging is related to more left ventricular reverse remodeling in nonischemic dilated cardiomyopathy

Introduction

Guideline-directed medical therapy can induce left ventricular reverse remodeling (LVRR) in nonischemic dilated cardiomyopathy (NIDCM). Some predictors for LVRR have been reported but, there were few studies about the relationship between cardiac magnetic resonance imaging (CMR) parameters and LVRR in NIDCM on optimal GDMT.

Methods

We retrospectively analyzed echocardiogram and CMR data of newly diagnosed 142 NIDCM patients (age: 57±16 years old, 71.8% male) in a single center from Jan 2012 to Dec 2017. NIDCM was defined as left ventricular ejection fraction (LVEF) <45% and the ischemic etiology was excluded by CMR, coronary angiography or coronary CT or SPECT scan. LVRR was defined as improvement in LVEF ≥10% during follow-up period (median 403 days).

Results

Baseline LVEF and LV end diastolic dimension (LVEDD) were 27±8% and 64±8 mm. There were 87 patients (61.3%) of LVRR in our cohort. In LVRR group, native T1 value was significantly lower (1326±66 for LVRR vs 1369±72ms, p<0.001), extracellular volume (ECV) was significantly lower (28.3±3.6 for LVRR vs 32.4±4.4%, p<0.001), and T2 value was significantly lower (49.6±4.6 for LVRR vs 52.1±5.4ms, p=0.004) compared with non-LVRR group. ECV was an independent predictor for LVRR after adjusting current LVRR predictors such as age, sex, LVEF, LVEDD, systolic blood pressure, heart rate and QRS duration (Odd ratio 0.706, 95% confidence interval 0.616–0.809, p<0.001).

Conclusion

Lower native T1, ECV and T2 on CMR is related to higher incidence of LVRR in NIDCM. Further larger prospective study should be warranted to confirm the relationship between CMR parameters and LVRR in NIDCM.

Optical performance of a dielectric-metal-dielectric antireflective absorber structure

The absorption of electromagnetic radiation by a planar structure, consisting of a three-layer dielectric-metal-dielectric coating on a metal backreflector, is analyzed. The conditions for total absorption are derived. Our analysis shows that, in contrast with bi-layer structures, the calculated layer thicknesses are feasible to fabricate for any metal. The proposed absorber design is of potential use in infrared, terahertz, and longer wavelength detectors and for radiant energy harvesting devices.

Traumatic brain injury, dry eye and comorbid pain diagnoses in US veterans

AIMS

The purpose of the study is to evaluate the relationship between dry eye (DE) and pain diagnoses in US veterans with and without traumatic brain injury (TBI).

METHODS

Retrospective cohort study of veterans who were seen in the Veterans Administration Hospital (VA) between 1 January 2010 and 31 December 2014. Veterans were separated into two groups by the presence or absence of an International Classification of Diseases, Ninth Revision diagnosis of TBI and assessed for DE and other comorbidities. A dendrogram was used to investigate the linkage between TBI, DE, chronic pain and other comorbid conditions.

RESULTS

Of the 3 265 894 veterans seen during the 5-year period, 3.97% carried a diagnosis of TBI. Veterans with TBI were more likely to have a diagnosis of DE compared with their counterparts without TBI (37.2% vs 29.1%, p<0.0005). The association was stronger between TBI and ocular pain (OR 3.08; 95% CI 3.03 to 3.13) compared with tear film dysfunction (OR 1.09; 95% CI 1.07 to 1.10). Those with TBI were also about twice as likely to have a diagnosis of chronic pain, headache, depression or post-traumatic stress disorder compared with their counterparts without TBI. Cluster analysis of TBI, DE and pain diagnoses of interest revealed that central pain syndrome, cluster headache, sicca syndrome, keratoconjunctivitis sicca and late effect of injury to the nervous system (as can be seen after TBI) were all closely clustered together.

CONCLUSIONS

DE and pain disorders occur at higher frequencies in patients with a diagnosis of TBI, suggesting a common underlying pathophysiology.

Astrocytic water channel aquaporin-4 modulates brain plasticity in both mice and humans: a potential gliogenetic mechanism underlying language-associated learning

The role of astrocytes in brain plasticity has not been extensively studied compared with that of neurons. Here we adopted integrative translational and reverse-translational approaches to explore the role of an astrocyte-specific major water channel in the brain, aquaporin-4 (AQP4), in brain plasticity and learning. We initially identified the most prevalent genetic variant of AQP4 (single nucleotide polymorphism of rs162008 with C or T variation, which has a minor allele frequency of 0.21) from a human database (n=60 706) and examined its functionality in modulating the expression level of AQP4 in an in vitro luciferase reporter assay. In the following experiments, AQP4 knock-down in mice not only impaired hippocampal volumetric plasticity after exposure to enriched environment but also caused loss of long-term potentiation after theta-burst stimulation. In humans, there was a cross-sectional association of rs162008 with gray matter (GM) volume variation in cortices, including the vicinity of the Perisylvian heteromodal language area (Sample 1, n=650). GM volume variation in these brain regions was positively associated with the semantic verbal fluency. In a prospective follow-up study (Sample 2, n=45), the effects of an intensive 5-week foreign language (English) learning experience on regional GM volume increase were modulated by this AQP4 variant, which was also associated with verbal learning capacity change. We then delineated in mice mechanisms that included AQP4-dependent transient astrocytic volume changes and astrocytic structural elaboration. We believe our study provides the first integrative evidence for a gliogenetic basis that involves AQP4, underlying language-associated brain plasticity.

Anatomy of STEM teaching in North American universities

National and local initiatives focused on the transformation of STEM teaching in higher education have multiplied over the last decade. These initiatives often focus on measuring change in instructional practices, but it is difficult to monitor such change without a national picture of STEM educational practices, especially as characterized by common observational instruments. We characterized a snapshot of this landscape by conducting the first large scale observation-based study. We found that lecturing was prominent throughout the undergraduate STEM curriculum, even in classrooms with infrastructure designed to support active learning, indicating that further work is required to reform STEM education. Additionally, we established that STEM faculty’s instructional practices can vary substantially within a course, invalidating the commonly-used teaching evaluations based on a one-time observation.

Although lecture is prominent throughout the undergraduate STEM curriculum, STEM faculty employ varied teaching practices within the same course.