Maternal androgen excess inhibits fetal cardiomyocytes proliferation through RB-mediated cell cycle arrest and induces cardiac hypertrophy in adulthood

PURPOSE

Maternal hyperandrogenism during pregnancy is associated with adverse gestational outcomes and chronic non-communicable diseases in offspring. However, few studies are reported to demonstrate the association between maternal androgen excess and cardiac health in offspring. This study aimed to explore the relation between androgen exposure in utero and cardiac health of offspring in fetal and adult period. Its underlying mechanism is also illustrated in this research.

METHODS

Pregnant mice were injected with dihydrotestosterone (DHT) from gestational day (GD) 16.5 to GD18.5. On GD18.5, fetal heart tissue was collected for metabolite and morphological analysis. The hearts from adult offspring were also collected for morphological and qPCR analysis. H9c2 cells were treated with 75 μM androsterone. Immunofluorescence, flow cytometry, qPCR, and western blot were performed to observe cell proliferation and explore the underlying mechanism.

RESULTS

Intrauterine exposure to excessive androgen led to thinner ventricular wall, decreased number of cardiomyocytes in fetal offspring and caused cardiac hypertrophy, compromised cardiac function in adult offspring. The analysis of steroid hormone metabolites in fetal heart tissue by ultra performance liquid chromatography and tandem mass spectrometry showed that the content of androgen metabolite androsterone was significantly increased. Mechanistically, H9c2 cells treated with androsterone led to a significant decrease in phosphorylated retinoblastoma protein (pRB) and cell cycle-related protein including cyclin-dependent kinase 2 (CDK2), cyclin-dependent kinase 4 (CDK4), and cyclin D1 (CCND1) in cardiomyocytes. This resulted in cell cycle arrest at G1-S phase, which in turn inhibited cardiomyocyte proliferation.

CONCLUSION

Taken together, our results indicate that in utero exposure to DHT, its metabolite androsterone could directly decrease cardiomyocytes proliferation through cell cycle arrest, which has a life-long-lasting effect on cardiac health. Our study highlights the importance of monitoring sex hormones in women during pregnancy and the follow-up of cardiac function in offspring with high risk of intrauterine androgen exposure.

CD8 cytotoxic T-cell infiltrates and cellular damage in the hypothalamus in human obesity

Rare cases of paraneoplastic obesity in children suggest sporadic obesity might also arise from an adaptive immune cell-mediated mechanism. Since the hypothalamus is a central regulator of feeding behavior and energy expenditure, we quantified lymphocytic inflammation in this region in a cohort of obese and non-obese human post-mortem brains. We report that CD8-positive cytotoxic T-cells are increased in hypothalamic median eminence/arcuate nucleus (ME/Arc) and bed nucleus of the stria terminalis in 40% of obese compared to non-obese patients, but not in other hypothalamic nuclei or brain regions. CD8 T-cells were most abundant in individuals with concurrent obesity and diabetes. Markers of cytotoxic T-cell induced damage, activated caspase 3 and poly-ADP ribose, were also elevated in the ME/Arc of obese patients. To provoke CD8 cytotoxic T-cell infiltrates in ventromedial region of hypothalamus in mice we performed stereotactic injections of an adeno-associated virus expressing immunogenic green fluorescent protein or saline. AAV but not saline injections triggered hypothalamic CD8 T-cell infiltrates associated with a rapid weight gain in mice recapitulating the findings in human obesity. This is the first description of the neuropathology of human obesity and when combined with its reconstitution in a mouse model suggests adaptive immunity may drive as much as 40% of the human condition.

[LINC00926 promotes pyroptosis of hypoxia-induced human umbilical vein vascular endothelial cells by recruiting ELAVL1]

OBJECTIVE

To investigate the regulatory role of the long non-coding RNA LINC00926 in pyroptosis of hypoxia-induced human umbilical vein vascular endothelial cells (HUVECs) and explore the molecular mechanism.

METHODS

HUVECs were transfected with a LINC00926-overexpressing plasmid (OE-LINC00926), a siRNA targeting ELAVL1, or both, followed by exposure to hypoxia (5% O2) or normoxia. The expression of LINC00926 and ELAVL1 in hypoxia-treated HUVECs was detected using real-time quantitative PCR (RT-qPCR) and Western blotting. Cell proliferation was detected using Cell Counting Kit-8 (CCK-8), and the levels of IL-1β in the cell cultures was determined with ELISA. The protein expression levels of pyroptosis-related proteins (caspase-1, cleaved caspase-1 and NLRP3) in the treated cells were analyzed using Western blotting, and the binding between LINC00926 and ELAVL1 was verified with RNA immunoprecipitation (RIP) assay.

RESULTS

Exposure to hypoxia obviously up-regulated the mRNA expression of LINC00926 and the protein expression of ELAVL1 in HUVECs, but did not affect the mRNA expression of ELAVL1. LINC00926 overexpression in the cells significantly inhibited cell proliferation, increased IL-1β level and enhanced the expressions of pyroptosis-related proteins (all P < 0.05). LINC00926 overexpression further up-regulated the protein expression of ELAVL1 in hypoxia-exposed HUVECs. The results of RIP assay confirmed the binding between LINC00926 and ELAVL1. ELAVL1 knockdown significantly decreased IL-1β level and the expressions of pyroptosis-related proteins in hypoxia-exposed HUVECs (P < 0.05), while LINC00926 overexpression partially reversed the effects of ELAVL1 knockdown.

CONCLUSION

LINC00926 promotes pyroptosis of hypoxia-induced HUVECs by recruiting ELAVL1.

Hominoid SVA-lncRNA AK057321 targets human-specific SVA retrotransposons in SCN8A and CDK5RAP2 to initiate neuronal maturation

SINE-VNTR-Alu (SVA) retrotransposons arose and expanded in the genome of hominoid primates concurrent with the slowing of brain maturation. We report genes with intronic SVA transposons are enriched for neurodevelopmental disease and transcribed into long non-coding SVA-lncRNAs. Human-specific SVAs in microcephaly CDK5RAP2 and epilepsy SCN8A gene introns repress their expression via transcription factor ZNF91 to delay neuronal maturation. Deleting the SVA in CDK5RAP2 initiates multi-dimensional and in SCN8A selective sodium current neuronal maturation by upregulating these genes. SVA-lncRNA AK057321 forms RNA:DNA heteroduplexes with the genomic SVAs and upregulates these genes to initiate neuronal maturation. SVA-lncRNA AK057321 also promotes species-specific cortex and cerebellum-enriched expression upregulating human genes with intronic SVAs (e.g., HTT, CHAF1B and KCNJ6) but not mouse orthologs. The diversity of neuronal genes with intronic SVAs suggest this hominoid-specific SVA transposon-based gene regulatory mechanism may act at multiple steps to specialize and achieve neoteny of the human brain.

UBE3A and transsynaptic complex NRXN1-CBLN1-GluD1 in a hypothalamic VMHvl-arcuate feedback circuit regulates aggression

The circuit origins of aggression in autism spectrum disorder remain undefined. Here we report Tac1-expressing glutamatergic neurons in ventrolateral division of ventromedial hypothalamus (VMHvl) drive intermale aggression. Aggression is increased due to increases of Ube3a gene dosage in the VMHvl neurons when modeling autism due to maternal 15q11-13 triplication. Targeted deletion of increased Ube3a copies in VMHvl reverses the elevated aggression adult mice. VMHvl neurons form excitatory synapses onto hypothalamic arcuate nucleus AgRP/NPY neurons through a NRXN1-CBLN1-GluD1 transsynaptic complex and UBE3A impairs this synapse by decreasing Cbln1 gene expression. Exciting AgRP/NPY arcuate neurons leads to feedback inhibition of VMHvl neurons and inhibits aggression. Asymptomatic increases of UBE3A synergize with a heterozygous deficiency of presynaptic Nrxn1 or postsynaptic Grid1 (both ASD genes) to increase aggression. Targeted deletions of Grid1 in arcuate AgRP neurons impairs the VMHvl to AgRP/NPY neuron excitatory synapses while increasing aggression. Chemogenetic/optogenetic activation of arcuate AgRP/NPY neurons inhibits VMHvl neurons and represses aggression. These data reveal that multiple autism genes converge to regulate the VMHvl-arcuate AgRP/NPY glutamatergic synapse. The hypothalamic circuitry implicated by these data suggest impaired excitation of AgRP/NPY feedback inhibitory neurons may explain the increased aggression behavior found in genetic forms of autism.

Changes in integrins αv and α5 with Nogo-A in the rat retina after optic nerve injury

OBJECTIVE

  The purpose of this study was to investigate whether integrin levels are associated with axon regeneration after central nervous system (CNS) injury.

MATERIALS AND METHODS

By using immunohistochemistry, we performed a detailed investigation of the changes in and colocalization of integrins αv and α5, with Nogo-A in the retina after optic nerve injury.

RESULTS

We confirmed that integrins αv and α5 were expressed in the rat retina and colocalized with Nogo-A. After optic nerve transection, we found that integrin α5 levels increased over 7 days, but integrin αv levels remained unchanged, while Nogo-A levels increased.

CONCLUSIONS

It seems that the inhibition of axonal regeneration by the Amino-Nogo-integrin signaling pathway may not occur via changes in integrin levels.

[Susceptibility and mechanism of sodium salicylate-induced tinnitus model in low estrogen rats]

Objective: The susceptibility of tinnitus rats with low estrogen level induced by sodium salicylate and the changes of tumor necrosis factor α (TNF-α) in serum were observed to investigate the relationship between tinnitus occurrence and estrogen level. Methods: Forty-two healthy female Wistar rats were randomly divided into control group(n=6), normal group(n=6), sham operation group(n=6) and ovariectomized group(n=24). Control group was intraperitoneally injected with normal saline 200 mg/kg for 14 consecutive days. Normal group, sham operation group and ovariectomized group were intraperitoneally injected with sodium salicylate 200 mg/kg for 14 consecutive days. Before and after sodium salicylate induction, the tinnitus behavior of rats in each group was detected by prepulse inhibition (PPI) and gap pre-pulse inhibition of the acoustic startle (GPIAS) test. Before and after sodium salicylate induction, blood samples were collected from eyeballs of rats in each group, and serum levels of estradiol and TNF-α were detected by ELISA. SPSS 25.0 software was used to analyze the data. Results: (1) Following 14 days of sodium salicylate intervention, there was no significant difference in PPI inhibition rate between groups or within groups(all P>0.05). (2)There was no significant difference in the inhibition rate of GPIAS in the four groups before sodium salicylate injection(F=0.217, P>0.05). With sodium salicylate injected for 14 days, the inhibition rate of GPIAS in ovariectomized group (30.88%±15.40%) was significantly lower than that in the other three groups (44.11%±21.06%, 38.27%±10.92%, 51.59%±11.34%), and the difference was statistically significant(F=3.533, P<0.05). The inhibition rate of GPIAS in ovariectomized group with sodium salicylate injected for 14 days was significantly lower than that before injection, and the difference was statistically significant(t=2.977, P<0.05).There was no significant difference in GPIAS inhibition rate between the other three groups before and after sodium salicylate injection(P>0.05). (3)The level of TNF-α in ovariectomized rats was significantly higher than that in the other three groups, the difference was statistically significant(all P<0.05). With sodium salicylate injection for 14 days, TNF-α level in the ovariectomized group increased more significantly than that in the other three groups, the difference was statistically significant(F=8.045, P<0.05). TNF-α levels increased following salicylate injection in normal group, sham operation group and ovariectomized group, and the differences were statistically significant(t value was -4.843, -4.932 and -5.965 respectively, each P<0.05). There was no significant difference in TNF-α levels before and after normal saline injection in control group(all P>0.05). Conclusion: Low estrogen levels increase susceptibility to sodium salicylate-induced tinnitus. Decreased estrogen levels may increase susceptibility to tinnitus through the increased expression of pro-inflammatory factor TNF-α.

CIP2A deficiency promotes depression-like behaviors in mice through inhibition of dendritic arborization

Major depressive disorder (MDD) is a severe mental illness. Decreased brain plasticity and dendritic fields have been consistently found in MDD patients and animal models; however, the underlying molecular mechanisms remain to be clarified. Here, we demonstrate that the deletion of cancerous inhibitor of PP2A (CIP2A), an endogenous inhibitor of protein phosphatase 2A (PP2A), leads to depression-like behaviors in mice. Hippocampal RNA sequencing analysis of CIP2A knockout mice shows alterations in the PI3K-AKT pathway and central nervous system development. In primary neurons, CIP2A stimulates AKT activity and promotes dendritic development. Further analysis reveals that the effect of CIP2A in promoting dendritic development is dependent on PP2A-AKT signaling. In vivo, CIP2A deficiency-induced depression-like behaviors and impaired dendritic arborization are rescued by AKT activation. Decreased CIP2A expression and impaired dendrite branching are observed in a mouse model of chronic unpredictable mild stress (CUMS). Indicative of clinical relevance to humans, CIP2A expression is found decreased in transcriptomes from MDD patients. In conclusion, we discover a novel mechanism that CIP2A deficiency promotes depression through the regulation of PP2A-AKT signaling and dendritic arborization.

Prkn knockout mice show autistic-like behaviors and aberrant synapse formation

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with high genetic heterogeneity, affecting one in 44 children in the United States. Recent genomic sequencing studies from autistic human individuals indicate that PARK2, a gene that has long been considered in the pathogenesis of Parkinson's disease, is involved in ASD. Here, we report that Prkn knockout (KO) mice demonstrate autistic-like behaviors including impaired social interaction, elevated repetitive behaviors, and deficits in communication. In addition, Prkn KO mice show reduced neuronal activity in the context of sociability in the prelimbic cortex. Cell morphological examination of layer 5 prelimbic cortical neurons shows a reduction in dendritic arborization and spine number. Furthermore, biochemistry and immunocytochemistry analyses reveal alterations in synapse density and the molecular composition of synapses. These findings indicate that Prkn is implicated in brain development and suggest the potential use of the Prkn KO mouse as a model for autism research.

Role of the DUB enzyme USP7 in dendritic arborization, neuronal migration, and autistic-like behaviors in mice

Duplication and haploinsufficiency of the USP7 gene are implicated in autism spectrum disorders (ASD), but the role for USP7 in neurodevelopment and contribution to ASD pathogenesis remain unknown. We find that in primary neurons, overexpression of USP7 increases dendritic branch number and total dendritic length, whereas knockdown leads to opposite alterations. Besides, USP7 deubiquitinates the X-linked inhibitor of apoptosis protein (XIAP). The USP7-induced increase in XIAP suppresses caspase 3 activity, leading to a reduction in tubulin cleavage and suppression of dendritic pruning. When USP7 is introduced into the brains of prenatal mice via in utero electroporation (IUE), it results in abnormal migration of newborn neurons and increased dendritic arborization. Importantly, intraventricular brain injection of AAV-USP7 in P0 mice leads to autistic-like phenotypes including aberrant social interactions, repetitive behaviors, as well as changes in somatosensory sensitivity. These findings provide new insights in USP7-related neurobiological functions and its implication in ASD.

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Overexpression of USP7 increases dendritic arborization

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USP7 targets XIAP for deubiquitination and regulates XIAP proteostasis in neurons

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USP7 regulates dendritic remodeling via the XIAP-caspase 3-tubulin pathway

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Prenatal overexpression of USP7 in mice leads to autistic-like behaviors

Regulatory Effects of Gradient Microtopographies on Synapse Formation and Neurite Growth in Hippocampal Neurons

Among approaches aiming toward functional nervous system restoration, those implementing microfabrication techniques allow the manufacture of platforms with distinct geometry where neurons can develop and be guided to form patterned connections in vitro. The interplay between neuronal development and the microenvironment, shaped by the physical limitations, remains largely unknown. Therefore, it is crucial to have an efficient way to quantify neuronal morphological changes induced by physical or contact guidance of the microenvironment. In this study, we first devise and assess a method to prepare anisotropic, gradient poly(dimethylsiloxane) micro-ridge/groove arrays featuring variable local pattern width. We then demonstrate the ability of this single substrate to simultaneously profile the morphologcial and synaptic connectivity changes of primary cultured hippocampal neurons reacting to variable physical conditons, throughout neurodevelopment, in vitro. The gradient microtopography enhanced adhesion within microgrooves, increasing soma density with decreasing pattern width. Decreasing pattern width also reduced dendritic arborization and increased preferential axon growth. Finally, decreasing pattern geometry inhibited presynaptic puncta architecture. Collectively, a method to examine structural development and connectivity in response to physical stimuli is established, and potentially provides insight into microfabricated geometries which promote neural regeneration and repair.

Prognostic value of a novel index: computational pressure-flow dynamics derived fractional flow reserve in patients with stable coronary artery disease treated with optimal medical therapy alone

Background

The use of fractional flow reserve (FFR) is limited due to the need of invasive pressure wire and hyperaemic stimulus. Computational pressure-flow dynamics derived fractional flow reserve (caFFR) is a novel non-invasive index to determine the FFR in patients with stable coronary artery disease (CAD).

Purpose

The clinical value of caFFR remains uncertain. The aim of the study is to evaluate the prognostic role of caFFR in patients with stable CAD who were treated by optimal medical therapy alone.

Methods

A total of 558 stable CAD patients (mean age=64.5±11.2, 59.0% male) with ≥1 coronary lesion detected during conventional coronary angiogram were included. All of them did not undergo percutaneous coronary intervention and were treated with optimal medical therapy alone. Patients were then classified into 4 groups according to their caFFR value; caFFR ≤0.70 (n=40), caFFR = 0.71–0.80 (n=28), caFFR = 0.81–0.90 (n=292), caFFR = 0.91–1.00 (n=198), with a lower caFFR indicating a greater magnitude of myocardial ischemia. The primary endpoint was 3-year major adverse cardiac events (MACE), defined as a composite of all-cause mortality, myocardial infarction or any unplanned revascularization.

Results

During a median follow-up of 36 months, a total of 49 composite events occurred, including 27 all-cause mortality, 4 myocardial infarction and 18 unplanned revascularization.

After multivariate adjustment, caFFR was an independent predictor of MACE (adjusted hazard ratio [HR] = 0.97 per 0.01 increase in caFFR; 95% confidence interval [Cl], 0.95–0.99; P&lt;0.01), all-cause mortality (adjusted HR = 0.96 per 0.01 increase in caFFR; 95% Cl, 0.94–0.99; P&lt;0.01), and stroke (adjusted HR = 0.95 per 0.01 increase in caFFR; 95% Cl, 0.90–0.99; P=0.03).

The area under the curve (AUC) by receiver-operating characteristic curve analysis (ROC) is 0.70 (95% Cl, 0.62–0.78; P&lt;0.01). The optimal cut-off of caFFR defined by ROC analysis for predicting MACE is 0.80, concluding that patients with caFFR ≤0.80 have significantly higher adverse event rate, which is consistent with the cut-off from wire-based FFR.

Using caFFR = 0.91–1.00 as reference, the risk of MACE was highest in patients with caFFR ≤0.70 (adjusted HR = 4.65; 95% Cl, 1.81–11.94; P&lt;0.01), followed by caFFR = 0.71–0.80 (adjusted HR = 3.67; 95% Cl, 1.12–11.33; P=0.02). The risk of MACE was nonetheless similar among patients with caFFR &gt;0.8 (adjusted HR = 1.39; 95% Cl, 0.61–3.19, P=0.44).

Conclusion

In patients with stable CAD who were treated with optimal medical therapy alone, those with more significant myocardial ischemia, indicated by lower caFFR, had higher risks of adverse outcomes. The finding thus supports the use of this non invasive index to quantify the severity of myocardial ischemia, improve risk-stratification, and predict adverse outcomes in patients with stable CAD.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): The University of Hong Kong, Queen Mary Hospital

Association between non-wire based computational angiography fractional flow reserve treatment threshold and major adverse cardiac events in patients with stable coronary artery disease

Introduction

Despite class IA guideline recommendations, the use of fractional flow reserve (FFR) in guiding percutaneous coronary intervention (PCI) in stable coronary artery disease (CAD) patients remains low due to limitations including the need of guidewire placement and hyperaemic stimulus. A novel non-invasive index, computational pressure-flow dynamics derived FFR (caFFR), was developed for measuring functional myocardial ischemia and overcoming the limitations of FFR. However, the clinical relevance of caFFR remains to be investigated. In the present study, we aim at evaluating the prognostic value of caFFR among stable CAD patients.

Methods

We retrospectively included patients with stable CAD who underwent coronary angiography during 2014–2016 at our center. Based on the caFFR value, patients were considered to be ischemic (caFFR ≤0.8) and non-ischemic (caFFR &gt;0.8). Further, we recombined the patients to form the adherence cohort, where patients were defined as adherent-to-caFFR if they were ischemic with PCI or non-ischemic without PCI, and nonadherent-to-caFFR if they were ischemic without PCI or non-ischemic with PCI. The primary endpoint was major adverse cardiac events (MACE), defined as a composite of all-cause mortality, non-fatal myocardial infarction, and any revascularization. Inverse probability of treatment weighting was used to account for treatment selection bias (PCI vs without PCI, or adherent vs non-adherent), and Cox proportional hazard model was used to evaluate the association with MACE.

Results

A total of 1322 patients, 782 patients in the ischemic cohort and 540 patients in the non-ischemic cohort respectively, were included in our analysis. PCI was associated with a lower risk of MACE in the ischemic cohort (hazard ratio [HR] 0.52; 95% confidence interval [CI], 0.34–0.80; P=0.002), but was not associated with MACE in the non-ischemic cohort. In the adherence cohort, adherent-to-caFFR group (n=803) had a lower risk of MACE compared with nonadherent-to-caFFR group (n=566) (HR, 0.61; 95% CI, 0.44–0.85; P=0.003).

Conclusion

Our study is the first to demonstrate the prognostic value of caFFR, a non-wire based assessment of myocardial ischemia, in patients with stable CAD undergoing PCI. These findings support the use of caFFR that bears the potential of a wider adoption compared with wire-based FFR through a reduction in procedure time, risk and costs.

Funding Acknowledgement

Type of funding sources: None. Weighted Kaplan-Meier curvesWeighted Cox proportional hazards model

Prognostic value of per-vessel treatment adherence in stable coronary artery disease based on novel computational pressure-flow dynamics derived fractional flow reserve

Background

Computational pressure-flow dynamics derived fractional flow reserve (caFFR) is a novel index developed to evaluate the extent of myocardial ischemia in patients with coronary artery disease (CAD), which eliminates the need of invasive pressure guidewire and hyperaemic stimulus in conventional fractional flow reserve (FFR) measurement. Studies have shown improved clinical outcomes associated with adherence to functional myocardial ischemia assessment when deciding to perform percutaneous coronary intervention (PCI) at a per-patient level. However, the clinical significance of such treatment adherence at a per-vessel level remains uncertain.

Methods

A total of 928 patients (mean age 66.2±10.5, male 72.7%) with stable CAD were included in this study. The caFFR of all three major coronary vessels were obtained for every patient, and the FFR threshold of 0.8 was adopted as the threshold for caFFR to indicate functionally significant artery stenosis which warrants PCI, and vice versa. Based on the caFFR of each major coronary vessel and whether PCI was performed to the respective vessel, patients were stratified into 0–1 vessel with treatment adherence group (group 1) (n=105), 2 vessels with treatment adherence group (group 2) (n=338), and 3 vessels with treatment adherence group (group 3) (n=485). The primary endpoint was major adverse cardiac events (MACE), defined as a composite of all-cause mortality, non-fatal myocardial infarction and any subsequent revascularization.

Results

The severity of CAD based on SYNTAX score assessment was 18.6±10.2 in group 1, 14.6±8.9 in group 2, and 11.5±9.9 in group 3 (P&lt;0.001). The rates of MACE at 3 years were significantly different across groups 1, 2 and 3 (17.1% vs. 12.1% vs. 7.4%; P=0.004). With reference to group 3, the risk of MACE at 3 years was increased in group 2 (adjusted hazard ratio [HR]=1.597; 95% confidence interval [CI]=1.020–2.501; P=0.041), and further increased in group 1 (adjusted HR=1.933; 95% CI=1.081–3.457; P=0.026).

Conclusion

In stable CAD patients, the risk of MACE is incremental when fewer major coronary vessels are treated with adherence to caFFR threshold of 0.8. Per-vessel treatment adherence significantly affects clinical outcomes in terms of MACE.

Funding Acknowledgement

Type of funding sources: None.

Long-term prognostic implications of PCI in ACS patients without ischemia on the basis of computational pressure-flow dynamics derived fractional flow reserve

Background

A substantial proportion of patients with acute coronary syndrome (ACS) may have intermediate lesion that are non-ischemic during emergency coronary angiography. The prognosis of such patients, compared to those with stable ischemic heart disease (SIHD) without ischemic lesion is however uncertain. Recently, a novel index, computational pressure-flow dynamics derived fractional flow reserve (caFFR), has been developed to assess myocardial ischemia, without the need of invasive pressure wire and hyperaemic stimulus as required in conventional fractional flow reserve (FFR). By utilizing caFFR to assess for ischaemic status during coronary angiography, the aim of our study is first to assess the prognostic difference between ACS and SIHD with non-ischaemia intermediate lesions. Second, we ascertain whether PCI in patients with ACS with non-ischaemia intermediate lesions provides survival benefit in addition to medical therapy.

Methods

We retrospectively recruited 551 patients (mean age 64.4 years; male 59.9%) with absence of myocardial ischaemia, defined as caFFR ≥0.80 in all vessels, from our Hospital. Patients were stratified into those with index presentation of ACS (n=132) and those with SIHD (n=491). Among the ACS cohort, patients were further divided into those with PCI (n=83) and with medical therapy alone (n=49). The SIHD cohort (n=491), all of whom were treated with medical therapy alone, was considered as referent group. The primary end point was major adverse cardiovascular events (MACE) at 3 years, which was defined as a composite of all-cause mortality, non-fatal myocardial infarction (MI), and any unplanned revascularization.

Results

During a median follow-up of 36 months, 54 composite events occurred, including 38 all-cause mortality, 5 MI, and 14 unplanned revascularization. Compared to those with SIHD, patients with ACS was independently associated with MACE even in the absence of myocardial ischaemia (adjusted Hazard Ratios=2.531; 95% confidence interval=1.397–4.586; P=0.002). The 3-year incidence rate of MACE was the highest in ACS patients with medical therapy alone, followed by ACS patients with immediate PCI; the SIHD cohort had the lowest incidence rates (30.6% vs 12.0% vs 5.9%, P&lt;0.001). This was mainly driven by the rate of all-cause death (26.5% vs 12.0% vs 3.1%; P&lt;0.001). Similar findings were observed for hospitalisation due to heart failure (14.3% vs 6.0% vs 3.1%, P=0.031) and cardiac death (8.2% vs 4.8% vs 0.4%, P&lt;0.001) at 3 years.

Conclusion

In patients with intermediate lesion without myocardial ischaemia (defined as caFFR ≥0.8), those presented with ACS had a higher risk of MACE at 3 years compared to SIHD. Among ACS patients with intermediate lesion without myocardial ischaemia, PCI significantly reduces the rate of MACE. In patients with ACS, our finding suggests that PCI should be advocated to intermediate lesion even without myocardial ischaemia.

Funding Acknowledgement

Type of funding sources: None. Kaplan-Meier curve for MACECumulative Events at 3 Years

Treatment delay and reperfusion management of acute ST-segment elevation myocardial infarction: analysis of the China STEMI Care Project Phase 1

BACKGROUND

The China ST-segment elevation myocardial infarction (STEMI) Care Project (CSCAP) was launched in 2011 to address the problems of insufficient reperfusion and long treatment delay in STEMI care in China.

AIM

To describe the baseline status of STEMI emergency care in Tertiary PCI Hospitals using Phase 1 (CSCAP-1) data.

DESIGN

CSCAP-1 is a prospective multi-center STEMI registry.

METHODS AND RESULTS

A total of 4191 patients with symptom onset within 12 or 12-36 h requiring primary percutaneous coronary intervention (PCI), were enrolled from 53 tertiary PCI hospitals in 14 provinces, municipalities, and autonomous regions of China in CSCAP-1. Among them, 49.0% were self-transported to the hospital, 26.5% were transferred to the hospital by calling the emergency medical services directly, and 24.5% were transferred from other hospitals. In patients with symptom onset within 12 h, 83.2% received primary PCI, 5.9% received thrombolysis and 10.9% received conservative medications. The median door-to-balloon time was 115 (85-170) min and the median door-to-needle time for in-hospital thrombolysis was 80 (50-135) min. The overall in-hospital all-cause mortality was 2.4%, while it was 5.3% in the non-reperfusion group and 2.1% in the reperfusion group (P < 0.001).

CONCLUSION

Although a long treatment delay and a high proportion of patients transporting themselves to the hospital were observed, trends were positive with greater adoption of primary PCI and lower in-hospital mortality in tertiary hospitals in China. Our results provided important information for further integrated STEMI network construction in China.

Early results for iCMR in atrial flutter

Funding Acknowledgements

Type of funding sources: None.

Background

 As a standard of care, ablation of typical atrial flutter involves performing cardiac catheterization under x-ray fluoroscopy. The unique ability of magnetic resonance (MR) to provide real-time functional imaging in multiple views without ionizing radiation exposure has the potential to be a powerful tool for diagnostic and interventional procedures. Real-time MR imaging-guided radiofrequency (RF) ablation has been used as a part of clinical trials.

Objective

 To implement the MR imaging-guided RF ablation of typical atrial flutter in the clinical routine.

Methods

 From January to July 2020, 15 consecutive patients with typical atrial flutter have been referred for ablation. Patient preparation, conscious sedation and groin puncture took place inside the 1.5 Tesla MR scanner as a part of an MR-only workflow. The catheter advancement as well as the RF ablation procedure have been performed under direct visualisation of catheters with integrated micro-coils using an interactive sequence with active tip tracking and automatic slice positioning in the plane where the catheter tip has been detected. During catheter advancement a single frontal plane has been used to visualize the passage of the catheter through femoral veins and inferior vena cava. With both diagnostic and ablation catheters in the right atrium, an axial stack of balanced steady-state free precession acquisitions has been acquired and used to reconstruct planes in the short- and long cardiac axis. These have been used to provide a "left- and right anterior oblique" view familiar to an interventional electrophysiologist. The subsequent catheter placement and ablation have been performed under direct visualisation in these two planes (see figure).

Results

 The ablation was successful in 14 patients, one patient had to undergo a conventional procedure on the following day. The mean time to reach right atrium and coronary sinus was 4 [3,5] and 7 [6,10] minutes, respectively. The mean total ablation duration and procedure time was 18 [12,26] and 43 [33,58] minutes, respectively. There were no adverse events.

Conclusion

 The implementation of the MR imaging-guided RF ablation of typical atrial flutter in the clinical routine is feasible and leads to similar success rates and procedure times as the conventional fluoroscopy-based ablation.

Abstract Figure.

Ultrasonic evaluation of systemic and renal perfusion in sepsis patients before and after fluid resuscitation

OBJECTIVE

This study aimed to explore the significance of renal Doppler ultrasound in evaluating systemic and renal perfusion in sepsis patients before and after fluid resuscitation.

PATIENTS AND METHODS

Forty sepsis patients admitted to the Department of Intensive Medicine and intensive care unit (ICU) of the Fourth Hospital of Hebei Medical University from June 2014 to December 2014 were enrolled in this study, and 35 patients were included in the final analysis. These patients were divided into positive and negative fluid responsiveness groups. They were also divided into an acute kidney injury (AKI) group and a non-AKI group according to changes in creatinine and urine volume. The correlations of the changes in hemodynamics before and after fluid resuscitation in each group with the changes in renal resistance index (RRI) and renal blood flow (RBF) grades were evaluated.

RESULTS

Before and after fluid resuscitation, the heart rate (HR), blood creatinine (Cre), and lactate (Lac) levels of all patients, including the patients in the positive fluid responsiveness group decreased, and the stroke volume (SV) and central venous pressure (CVP) increased. Only HR decreased in the negative fluid responsiveness group. In the AKI group, HR, Cre, and Lac decreased, while in the non-AKI group, HR decreased, but CVP and SV increased. There were differences between HR, Lac, and change rate of Lac (Lac%) after fluid resuscitation for the positive and negative fluid responsiveness groups. There was no statistical difference between the RRI values of each group before and after fluid resuscitation. The RRI values of the AKI group were higher than those of the non-AKI group, while the AKI group's RBF grades were lower than those of the non-AKI group. The change rate of RRI (RRI%) was higher in the AKI group than in the non-AKI group. Except for the negative fluid responsiveness group, the RBF grade of each group increased.

CONCLUSIONS

The approach of RBF classification based on Doppler ultrasound can be used to evaluate the systemic and renal perfusion of patients with severe sepsis before and after fluid resuscitation, while the RRI value cannot be used for evaluation. However, the RRI value can be used as a dynamic index for the evaluation of renal perfusion in patients with AKI.

Tafolecimab, a novel potential long-acting PCSK9 monoclonal antibody: efficacy and safety in healthy and hypercholesterolemia subjects

Background

LDL cholesterol (LDL-C) is a well-established risk factor for cardiovascular disease. PCSK9 binds LDL receptors, targeting them for degradation. The dosing intervals for currently available PCSK9 monoclonal antibodies are once every 2 or 4 weeks. Tafolecimab, a novel recombinant human PCSK9 monoclonal antibody, was found to have higher affinity with PCSK9 and show longer LDL-C reduction compared to evolocumab in preclinical studies.

Purposes

The objectives for the SAD and MAD studies were to investigate the safety and efficacy of tafolecimab and explore the optimal dosing schedule.

Methods

The phase 1 study was a randomized, placebo-controlled, double-blind, single-ascending dose study (SAD) in Chinese healthy subjects, who were randomized 3:1 to tafolecimab and placebo (n=58). SAD subjects received tafolecimab subcutaneously at 25/75/150/300/450/600mg, or intravenously at 75/450mg, monitored up to day 84. The phase 2 study was a randomized, double-blind, placebo-controlled, repeated-dosing, multiple ascending dose (MAD) study in patients with hypercholesterolemia, who were randomized 4:1 to tafolecimab and placebo (n=60). MAD subjects received tafolecimab subcutaneously at 75/140mg every 2 weeks, 300/420mg every 4weeks, 450/600mg every 6 weeks up to day 84 or 98 with 3 months follow-up.

Results

In the SAD, the maximum mean reduction in LDL-C ranged from 52.2% to 72.1% and was achieved as early as 5 days (figure 1a). The duration of LDL-C reduction was tafolecimab dose dependent. In the MAD, the mean LDL-C concentrations were reduced by tafolecimab for each dose at 12 weeks relative to baseline (ranging from 54.30% to 72.26%; p&lt;0.001). Particularly, a 56.52% (−72.50%, −40.54%) reduction of LDL-C was observed in the cohort of 600mg Q6W. The effect sustained till week 14 (8 weeks after the last dose) where there was still a 43.46% (−60.96%, −25.96%) reduction from baseline (figure 1b). The mean reduction of Lp(a) at week 12 ranged from 24.04% to 50.59% relative to baseline. Tafolecimab reduced the other lipids when comparing with placebo. The pharmacokinetics/pharmadynamics (LDL-C) profiles of tafolecimab were well characterised and support the potential dosing interval of 6–8 weeks subcutaneously.

Both healthy and hypercholesterolemia subjects are generally tolerable to tafolecimab. Reported treatment-emergent adverse events (TEAEs) were: tafolecimab 23 (52.3%) vs. placebo 8 (57.1%); tafolecimab 34 (70.8%) vs. placebo 9 (75.0%) in the SAD and MAD respectively. There were no serious TEAEs or events leading to death or treatment discontinuation in both SAD and MAD.

Conclusions

Tafolecimab was well tolerated in both healthy and hypercholesterolemia in Chinese subjects, and improved lipid profile including LDL-C, Lp(a) and other lipids. The sustained effects on LDL-C suggests the potential of tafolecimab as a long-lasting PCSK9 inhibitor with dosing interval of 6–8 weeks or beyond.

Figure 1. LDL-C: Percent change from baseline

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Innovent Biologics (Suzhou), China

Effect of the baseline pulse wave velocity on short term and long term blood pressure control in primary hypertension

OBJECTIVES

Arterial stiffness may affect antihypertensive response to antihypertensive treatment. However, sufficient clinical evidence is lacking. This longitudinal study aimed to evaluate the effect of baseline arterial stiffness measured by the brachial-ankle pulse wave velocity (baPWV) on response to short-term and long-term enalapril-based treatment in 3310 hypertensive adults from the China Stroke Primary Prevention Trial (CSPPT).

METHODS AND RESULTS

Blood pressure (BP) measured at three months (short-term) in 2780 subjects, and the time-average on-treatment BP in 3310 subjects during a median of 4.5-year follow-ups (long-term) were analyzed in the study. After short-term antihypertensive treatment, every 1 m/s increase in baPWV denoted a 7% and 6% decreased chance of achieving systolic BP (SBP) control (odds ratio (OR), 0.93; 95% CI 0.90, 0.96; P < 0.001) and BP control (OR, 0.94; 95% CI 0.91, 0.97; P < 0.001), respectively, after adjustment for age, gender and other variables. After long-term treatment, every 1 m/s increase in baPWV posed an 7% and 6% greater risk of failing to attain SBP control (OR, 0.93; 95% CI 0.90, 0.95; P < 0.001) and BP control (OR, 0.94; 95% CI, 0.92, 0.96; P < 0.001), respectively, not regarding for DBP control after both short- and long-term treatment. Higher baseline baPWV significantly decreased SBP reduction both after three months and the median 4.5-year treatment, while increased DBP reduction after the median 4.5-year treatment.

CONCLUSIONS

Elevated baseline baPWV significantly decreased BP response to short-and long-term treatment in adults with primary hypertensive. Arterial stiffness improvement may be an essential target to achieve adequate BP control.

Gender and age differences in the association between sleep characteristics and fasting glucose levels in Chinese adults

AIM

The present study examined the associations between night-time sleep duration, midday napping duration and bedtime, and fasting glucose levels, and whether or not such associations are dependent on gender and age.

METHODS

This study was a cross-sectional analysis of 172,901 adults aged≥40 years living in mainland China. Sleep duration was obtained by self-reports of bedtime at night, waking-up time the next morning and average napping duration at midday. Fasting plasma glucose (FPG)≥7.0mmol/L was defined as hyperglycaemia. Independent associations between night-time sleep duration, midday naptime duration and bedtime with hyperglycaemia were evaluated using regression models.

RESULTS

Compared with night-time sleep durations of 6-7.9h, both short (<6h) and long (≥8h) night-time sleep durations were significantly associated with an increased risk of hyperglycaemia in women [odds ratio (OR): 1.12, 95% confidence interval (CI): 1.01-1.29 and OR: 1.14, 95% CI: 1.08-1.21, respectively], and revealed a U-shaped distribution of risk in women and no significant association in men. Long midday nap durations (≥1h) were significantly but weakly associated with hyperglycaemia (OR: 1.04, 95% CI: 1.01-1.09) compared with no napping without interactions from gender or age, whereas the association between bedtime and fasting glucose levels did vary according to gender and age.

CONCLUSION

Night-time sleep duration, midday napping duration and bedtime were all independently associated with the risk of hyperglycaemia, and some of the associations between these sleep characteristics and hyperglycaemia were gender- and age-dependent.

P457Incidence of LA fibrosis and substrate-based AF ablation success rates in HF patients

Funding Acknowledgements

The author(s) received no specific funding for this work.

Background

In heart failure (HF) patients, sinus rhythm maintenance after catheter ablation for atrial fibrillation (AF) is mandatory to achieve better long-term outcome. Presence of left atrial (LA) fibrosis significantly attenuates ablation success rates. Incidence of LA fibrosis and the effect of an individualized substrate-based ablation concept on rhythm outcome in HF patients with AF is unclear.

Methods

This study investigated 103 patients (64 years, 69% men) with persistent AF (79%) and left ventricular (LV) dysfunction (EF 33% IQR [25; 38]) undergoing first time AF ablation. Identification of LA fibrosis and selection of ablation strategy were based on sinus rhythm voltage mapping. All patients received pulmonary vein isolation (PVI). LA fibrosis ablation was individualized by (i) homogenization of small areas, (ii) linear lesions connecting fibrosis and anatomical obstacles and (iii) linear lesions isolating large fibrotic areas. Rhythm outcome was measured by continuous device monitoring (AF detection ≥ 6 min) or Holter-ECG. A total post-procedural AF burden &lt; 0.1% was defined as successful rhythm control.

Results

LA fibrosis in the overall cohort, in paroxysmal and persistent AF patients was detected in 39/103 (38%), 6/22 (27%) and 33/81 (41%), respectively. After 11 ± 5 months and 1.2 procedures/patient, freedom from AF recurrence was similar between patients with and without LA fibrosis (33/39 (84%) vs. 54/64 (84%); p = 0.485). With continuous monitoring, 73/87 (84%) patients recorded a total AF burden &lt; 0.1%. There was no significant difference in AF burden outcome between patients with and without LA fibrosis (3.1% SD ±17.4 vs. 2.2% SD ±8.1; p = 0.4). No correlation between presence or extent of LA fibrosis and AF burden was found; p = 0.299.

Conclusion

A substantial number of HF patients with AF have no evidence of LA fibrosis. Among HF patients with LA fibrosis, individualized substrate-based AF ablation beyond PVI was able to achieve similar ablation success.

[Contemporary epidemiology and treatment of hospitalized heart failure patients in real clinical practice in China]

Objective: To observe the etiology, comorbidities, clinical features and treatment patterns of hospitalized patients with heart failure (HF) in China. Methods: Data were collected prospectively on hospitalized patients with HF who were enrolled in China Heart Failure Center Registry Study from 169 participating hospitals from January 2017 to August 2018. In this cross-sectional study, patients were stratified by left ventricular ejection fraction (LVEF) category: heart failure with reduced ejection fraction (HFrEF, LVEF<40%); heart failure with mid-ranged ejection fraction (HFmrEF, 40%≤LVEF<50%) and heart failure with preserved ejection fraction (HFpEF, LVEF≥50%). The clinical data were collected, including demographic information, diagnosis, signs, electrocardiogram, echocardiography, laboratory tests, and treatment. Results: A total of 31 356 hospitalized patients with HF were included, 19 072 (60.8%) were males and the average age was (67.9±13.6) years old. The common causes of HF were hypertension (57.2%), coronary heart disease (54.6%), dilated cardiomyopathy (14.7%), valvular heart disease (9.2%). The common complications were atrial fibrillation/atrial flutter (34.1%), diabetes (29.2%), and anemia (26.7%). 32.8% of patients had a history of hospitalization for HF within the previous 12 months. There were 11 034 (35.2%) patients with HFrEF, 6 825 (21.8%) patients with HFmrEF and 13 497 (43.0%) patients with HFpEF. Compared with patients with HFpEF, patients with HFrEF had a lower systolic blood pressure ((124.7±21.1)mmHg(1 mmHg=0.133 kPa) vs. (134.9±22.9)mmHg), faster heart rate ((85±19) beats/minutes vs. (81±19)beats/minutes), and higher percentage of New York Heart Association (NYHA) class Ⅳ, smoking, alcohol, left bundle branch block, and QRS time≥130 ms, and higher levels of blood uric acid, BNP, and NT-proBNP (all P<0.05). Compared with patients with HFmrEF and HFrEF, patients with HFpEF were older, more women, and higher comorbidity burden including hypertension, atrial fibrillation/atrial flutter, anemia and chronic obstructive pulmonary disease (all P<0.05). HFmrEF took a mid-position between HFrEF and HFpEF in age, gender, heart rate, systolic blood pressure, hypertension, atrial fibrillation/atrial flutter, anemia, and chronic obstructive pulmonary disease (all P<0.05). Patients with HFmrEF had the highest proportion of coronary heart disease, myocardial infarction and percutaneous coronary intervention (all P<0.05). During hospitalization, loop diuretics were used in 90.2% of patients, and intravenous inotropics were used in 20.4% of patients. The use of ACEI/ARB/ARNI, β blockers and aldosterone receptor antagonists at discharge were 71.8%, 79.1% and 83.6% in HFrEF and 69.9%, 75.5% and 72.4% in HFmrEF, respectively. The use of digoxin at discharge was 25.3% (HFrEF 36.7%, HFmrEF 23.1%, HFpEF 17.0%). The rates of cardiac resynchronization therapy and implantable cardioverter defibrillator in HFrEF were 2.7% and 2.1%. Conclusions: Among the hospitalized patients with HF in China, coronary heart disease and hypertension are the mostly prevalent causes. HFpEF accounts for a large proportion of hospitalized patients with HF. HFrEF, HFmrEF and HFpEF have different etiology and clinical features. In real-world, there are still large gaps in the effective application of the guideline recommended therapies to HF patients, especially the non-pharmacological therapy option, which needs to be improved further in China.

5106A pattern-discovery-based outcome predictive tool integrated with clinical data repository: design and a case study on contrast related acute kidney injury

Introduction

Clinical data repositories (CDR) including electronic health record (EHR) data have great potential for outcome prediction and risk modeling. However, most CDRs were only used for data displaying, and using data from CDR for outcome prediction often requires careful study design and sophisticated modeling techniques before a hypothesis can be tested.

Purpose

We built a prediction tool integrated with CDR based on pattern discovery aiming to bridge the above gap and demonstrated a case study on contrast related acute kidney injury (AKI) with the system.

Methods

A cardiovascular CDR integrated with multiple hospital informatics systems was established. For the case study on AKI, we included patients undergoing cardiac catheterization from January 13, 2015 to April 27, 2017, excluding those with dialysis, end-stage renal disease, renal transplant, and missing pre- or post-procedural creatinine. To handle missing data, a prior-history-note composer was designed to fill in structured data of 14 diseases related to cardiovascular problem. Crucial data such as ejective fraction was extracted from the structured reports. AKI was defined according to Acute Kidney Injury Network by increase of serum creatinine from most recent baseline to the post-procedure 7-day peak. To build predictive modeling, we selected 17 variables covered in existing AKI models. Pattern discovery was recently developed as an interpretable predictive model which works on incomplete noisy data. In this study, we developed a pattern discovery based visual analytics tool, and trained it on 70% data up to August 2016 with three interactive knowledge incorporation modes to develop 3 models: 1) pure data-driven, 2) domain knowledge, and 3) clinician-interactive. In last two modes, a physician using the visual analytics could change the variables and further refine the model, respectively. We tested and compared it with other models on the 30% consecutive patients dated afterwards, which is shown in Figure 1.

Results

Among 2,560 patients in the final dataset with 17 pre-procedure variables derived from CDR data, 169 (7.3%) had AKI. We measured 4 existing models, whose areas under curves (AUCs) of receiver operating characteristics curve for the test set were 0.70 (Mehran's), 0.72 (Chen's), 0.67 (Gao's) and 0.62 (AGEF), respectively. A pure data-driven machine learning method achieves AUC of 0.72 (Easy Ensemble). The AUCs of our 3 models are 0.77, 0.80, 0.82, respectively, with the last being top where physician knowledge is incorporated.

Demo and demonstration

Conclusions

We developed a novel pattern-discovery-based outcome prediction tool integrated with CDR and purely using EHR data. On the case of predicting contrast related AKI, the tool showed user-friendliness by physicians, and demonstrated a competitive performance in comparison with the state-of-the-art models.

P1226Very low achieved low-density lipoprotein cholesterol level with alirocumab treatment after acute coronary syndrome: ODYSSEY OUTCOMES

Background

Recent guidelines for cholesterol management recognize uncertainty regarding long-term efficacy and safety of prolonged very low levels of LDL-C on treatment with a PCSK9 inhibitor, including risk of new-onset diabetes. ODYSSEY OUTCOMES used a treat-to-target approach to demonstrate reduction of coronary heart disease death, non-fatal myocardial infarction, ischaemic stroke, or unstable angina (MACE) with the PCSK9 inhibitor alirocumab (ALI) vs placebo (PBO) in 18,924 patients with recent acute coronary syndrome and elevated LDL-C despite intensive statin therapy. ALI was blindly adjusted (75 or 150 mg dose) to target LDL-C 0.6–1.3 mmol/L (25–50 mg/dL). To avoid sustained very low LDL-C, blind substitution of PBO for ALI was intended if 2 consecutive LDL-C levels were <0.39 mmol/L (15 mg/dL). Patients were followed for median of 2.8 years (maximum of 5 years).

Purpose

We report the efficacy and safety of ALI in patients who reached very low LDL-C (consecutively <0.39 mmol/L), compared with matched patients from the PBO group.

Methods

Of 9462 patients randomized to receive ALI, 730 (7.7%) reached very low LDL-C and had substitution of PBO a median 8.3 months after randomization. Using propensity score matching, they were compared (3:1) with 2152 patients initially assigned to PBO. Propensity score matching was also used to compare the incidence of new-onset diabetes in 525 patients without diabetes at baseline who had very low LDL-C levels on ALI with 1675 matched patients in the PBO group. Neurocognitive events and haemorrhagic stroke were also evaluated in relation to very low LDL-C.

Results

Overall, ALI reduced the incidence of MACE (9.5% vs 11.1%; HR 0.85, 95% CI 0.78–0.93; P<0.001). Characteristics used in propensity score matching (and associated with very low LDL-C on ALI) included sex (male), diabetes (present), baseline LDL-C and lipoprotein(a) (lower), region (Asia), statin treatment, smoking, hypertension, and body mass index. Despite being switched to PBO, patients with very low LDL-C on ALI had fewer MACE than matched patients from the PBO group (6.4% vs 8.5%; HR 0.71, 95% CI 0.52–0.98; P=0.039; Figure). Very low LDL-C on ALI was not associated with risk of new-onset diabetes, compared with matched patients from the PBO group (15.1% vs 13.0%; HR 1.10, 95% CI 0.85–1.43; P=0.46). There was no association of very low LDL-C on ALI with neurocognitive events or haemorrhagic stroke.

Conclusions

The overall efficacy of ALI on cardiovascular outcomes was not diminished by the patients who had blinded substitution of PBO for sustained very low LDL-C. Despite a short duration of active treatment, these patients had fewer MACE than matched controls from the PBO group. No adverse consequence of very low LDL-C was identified. However, because patients with sustained very low LDL-C were switched to PBO, the long-term safety of more prolonged very low LDL-C, including risk of new-onset diabetes, deserves further study.

Acknowledgement/Funding

Funded by Sanofi and Regeneron Pharmaceuticals

P613Cardiac magnetic resonance imaging derived left ventricular mechanical function in patients with atrial fibrillation and left atrial low voltage zones

Background

The relation of left atrial low voltage zones (LVZ) to left ventricular function in patients undergoing pulmonary vein isolation (PVI) is not known.

Objective

To explore the relationship of left atrial low voltage zones (LVZ) on left ventricular function in patients with atrial fibrillation.

Methods

From June to Nov. 2018, 107 (mean age 67y, 70 men, 73 persistent AF) consecutive patients with symptomatic AF underwent a PVI with LVZ mapping. Before PVI the left ventricular ejection fraction (EF) and stroke volume (SV) were measured by cardiac magnetic resonance imaging (CMR). From feature-tracking of CMR-cine images left ventricular global, systolic and diastolic longitudinal strains (GLS), circumferential strains (GCS) and radial strains (GRS) were calculated.

Results

Of 59 patients CMR scanning in sinus rhythm was performed, LVZ were present in 24 patients.

LVEF was significantly lower in patients with left atrial LVZ (62±9% vs. 55±15%) (p=0,03). Left ventricular stroke volume was significantly decreased by the extent of LVZ (94±23 vs. 72±21ml), (p=0,03).

The left ventricular diastolic strains during ventricular filling (caused by atrial contraction) of GLS (r=−0,52), GCS (r=−0,65) and GRS (r=−0,65) were highly signifcantly correlated to the occurence and extent of LVZ (each p<0,001 respectively).

The only systolic ventricular strain was GLS, which decreased (r=−0,3, p=0,03) by the occurance of atrial low voltage.

Conclusion

The active, atrial part of diastolic left ventricular filling properties is impaired by the occurrence and extent of left atrial LVZ. In patients with left atrial LVZ the left ventricular stroke volume and ejection fraction is decreased already in sinus rhythm. It seems possible that atrial mechanical dysfunction and presence of atrial low voltage maybe predicted by LV diastolic strain analysis.

P605Correlation of left atrial phasic transport function and arrhythmogenic substrate in patients with atrial fibrillation: cardiac magnetic resonance feature tracking and bipolar voltage mapping

Background

Bipolar voltage mapping is a widely accepted approach to identify areas of arrhythmogenic substrate in patients presenting for atrial fibrillation (AF) ablation.

However, until now little is known about the correlation of left atrial (LA) bipolar voltage distribution and LA transport function.

Purpose

To study the impact of LA low voltage zones (LVZ) on LA transport function.

Methods

107 consecutive patients presenting for ablation of symptomatic AF (34 paroxysmal AF, 73 persistent AF) were prospectively enrolled. Each patient underwent cardiac magnetic resonance imaging (CMR) within 24 hours prior to the ablation procedure. 59 patients were in sinus rhythm (SR) and 48 in AF. LA phasic indexed volumes (LAVi) and ejection fractions were calculated using biplane area length formula. In addition LA phasic strains and strain rates were analyzed using dedicated software (Figure 1A & B).

LA bipolar voltage mapping was performed prior to beginning of ablation in sinus rhythm using a 3-dimensional mapping system and LVZ were defined as areas of bipolar voltage <0.5mV.

Results

LVZ were present in 47 patients (23 in SR). The area of LVZ was 14.6cm2 (5.3–34.0). For patients in AF at the time of CMR only elevated minimal and maximal LAVi (p=0.001 and p=0.002 respectively) but no LA functional parameter was predictive for the occurrence of LVZ. In contrast for patients in SR all LA phasic volumes (endsystolic, pre atrial contraction and enddiastolic LAVi) and LA function parameters (passive, active and total ejection fraction (EF), reservoir, conduit and booster pump strains and strain rates) were predictive for the occurrence of LVZ. After clustered and pooled multivariate logistic regression only impaired booster pump strain rate was still predictive for occurrence of LVZ (OR 0.974, 95% CI 0.950–0.998, p=0.036).

In addition Pearson correlation analysis revealed a strong link between LA booster pump functional parameters and cm2 expansion of LVZ areas: LA active EF, LA booster pump strain and SR (r=−0.42, p=0.044; r=−0.47, p=0.024; r=−0.65, p=0.001 [Figure 1C] respectively).

Conclusion

For patients in SR LA transport function is closely linked to the occurrence of LA LVZ and outperforms LA volumetric measurements for the prediction of LA LVZ.

Furthermore LA booster pump function parameters show robust correlation to the extension of LA LVZ.

Amyloid-β Induces AMPA Receptor Ubiquitination and Degradation in Primary Neurons and Human Brains of Alzheimer's Disease

As the primary mediator for synaptic transmission, AMPA receptors (AMPARs) are crucial for synaptic plasticity and higher brain functions. A downregulation of AMPAR expression has been indicated as one of the early pathological molecular alterations in Alzheimer's disease (AD), presumably via amyloid-β (Aβ). However, the molecular mechanisms leading to the loss of AMPARs remain less clear. We report that in primary neurons, application of Aβ triggers AMPAR internalization accompanied with a decrease in cell-surface AMPAR expression. Importantly, in both Aβ-treated neurons and human brain tissue from AD patients, we observed a significant decrease in total AMPAR amount and an enhancement in AMPAR ubiquitination. Consistent with facilitated receptor degradation, AMPARs show higher turnover rates in the presence of Aβ. Furthermore, AD brain lysates and Aβ-incubated neurons show increased expression of the AMPAR E3 ligase Nedd4 and decreased expression of AMPAR deubiquitinase USP46. Changes in these enzymes are responsible for the Aβ-dependent AMPAR reduction. These findings indicate that AMPAR ubiquitination acts as the key molecular event leading to the loss of AMPARs and thus suppressed synaptic transmission in AD.

CIP2A-promoted astrogliosis induces AD-like synaptic degeneration and cognitive deficits

Reactive astrogliosis and early synaptic degeneration are 2 characteristic hallmarks in Alzheimer's disease (AD) brains, but a direct link between the 2 events has not been established. Here, we show that cancerous inhibitor of PP2A (CIP2A), a cancerous protein with high expression level in astrocytes, is upregulated in patients with AD and 3xTg-AD transgenic mice. Overexpression of CIP2A in astrocytes through adeno-associated virus infection both in cultured cells and in mice brains results in activation of astrocytes, increased production of cytokines and Aβ, and synaptic degeneration indicated by decreased levels of synaptic proteins, spine loss, and impairment in long-term potentiation. As a result of synaptic degeneration, CIP2A overexpression in astrocytes in vivo induces significant deficits in visual episodic memory detected by novel objective recognition test and spatial memory detected by Morris water maze. We conclude that CIP2A-promoted astrogliosis induces synaptic degeneration and cognitive deficits in AD.

Developmental role of adenosine kinase for the expression of sex-dependent neuropsychiatric behavior

Deficits in social memory, cognition, and aberrant responses to stimulants are common among persons affected by schizophrenia and other conditions with a presumed developmental etiology. We previously found that expression changes in the adenosine metabolizing enzyme adenosine kinase (ADK) in the adult brain are associated with deficits in various cognitive domains. To distinguish between developmental and adult functions of ADK, we used two transgenic mouse lines with widespread disruption of ADK expression in the adult brain, but differences in the onset of ADK deletion. Specifically, we compared Nestin-Cre^+/-:ADK-flox^fl/fl (ADK^ΔBrain) mice with global loss of ADK in the whole brain, beginning in mid-gestation and persisting for life, with Gfa2-Cre^+/-:ADK-flox^fl/fl (ADK^ΔAstro) mice that have normal ADK expression throughout development, but lose astrocyte-specific ADK-expression in young adulthood. Because ADK-expression in adulthood is generally confined to astrocytes, adult ADK^ΔAstro mice show a similar expression profile of ADK in key areas of the brain related to neuropsychiatric behavior, compared to adult ADK^ΔBrain mice. We sought to determine a neurodevelopmental role of ADK on the expression of psychiatric behaviors in adult male and female mice. Adult ADK^ΔBrain mice showed significant deficits in social memory in males, significant contextual learning impairments in both sexes, and a hyper-responsiveness to amphetamine in males. In contrast, ADK^ΔAstro mice showed normal social memory and contextual learning but hypo-responsiveness to amphetamine in males. Our results demonstrate a key developmental role of ADK in mediating behaviors in adulthood related to neuropsychiatric disease and support the greater prevalence of these disorders among males.

CIP2A Causes Tau/APP Phosphorylation, Synaptopathy, and Memory Deficits in Alzheimer's Disease

Protein phosphatase 2A (PP2A) inhibition causes hyperphosphorylation of tau and APP in Alzheimer's disease (AD). However, the mechanisms underlying the downregulation of PP2A activity in AD brain remain unclear. We demonstrate that Cancerous Inhibitor of PP2A (CIP2A), an endogenous PP2A inhibitor, is overexpressed in AD brain. CIP2A-mediated PP2A inhibition drives tau/APP hyperphosphorylation and increases APP β-cleavage and Aβ production. Increase in CIP2A expression also leads to tau mislocalization to dendrites and spines and synaptic degeneration. In mice, injection of AAV-CIP2A to hippocampus induced AD-like cognitive deficits and impairments in long-term potentiation (LTP) and exacerbated AD pathologies in neurons. Indicative of disease exacerbating the feedback loop, we found that increased CIP2A expression and PP2A inhibition in AD brains result from increased Aβ production. In summary, we show that CIP2A overexpression causes PP2A inhibition and AD-related cellular pathology and cognitive deficits, pointing to CIP2A as a potential target for AD therapy.

[Prognostic value of myeloperoxidase concentration in patients with acute coronary syndrome]

Objective: To evaluate the difference of plasma myeloperoxidase (MPO) level in different types of acute coronary syndrome (ACS) patients, and the value of baseline MPO level in predicting short-term and long-term outcomes in patients with ACS. Methods: The study cohort was derived from "the 12th Five-Year" National Science and Technology Support Program Project "Study on Comprehensive Intervention and Prognosis of Acute Coronary Syndrome" . We enrolled all hospitalized ACS patients who were enrolled in "the 12th Five-Year" cohort from January 1, 2011 to December 31, 2013. A total of 630 patients from 20 centers were enrolled. According to the diagnosis, the patients were divided into two groups: ST-segment elevation myocardial infarction (STEMI) group and non-ST-elevation acute coronary syndrome (NSTE-ACS) group. Plasma levels of MPO were measured by ELISA method. Cardiovascular events in the hospital were recorded. All patients were followed-up by telephone, follow-up ended December 31, 2015. The occurrence of major adverse cardiovascular events (MACE, defined as cardiac death, recurrent myocardial infarction, unscheduled coronary revascularization procedure and stroke) and all-cause death were recorded. Logistic regression analysis and Cox regression analysis were used to evaluate the predictive value of baseline MPO levels obtained during hospitalization and the long-term outcomes of ACS patients. Results: A total of 597 ACS patients were enrolled in final analysis. Level of plasma MPO in STEMI patients was significantly higher than that of NSTE-ACS patients (34.02(19.31, 67.87) μg/L vs. 27.25(16.69, 52.92) μg/L, P=0.028) . MPO was not related to the in-hospital cardiovascular events (OR=0.797, 95%CI 0.366-1.737, P=0.569). Follow up was completed in 476 patients, median follow-up time was 796 (32, 1 816) days. There were 23 all-cause deaths and 51 MACE. Plasma MPO level was not an independent predictor for all-cause death (HR=1.434, 95%CI 0.502-4.100, P=0.501) and MACE (HR=1.271, 95%CI 0.662-2.442, P=0.471). Conclusion: In hospitalized ACS patients, level of plasma MPO was significantly higher in STEMI patients than in NSTE-ACS patients, but MPO could not predict the short-term or long-term outcomes in patients with ACS.

[In vivo imaging of breast tumors by a 99mTc radiolabeled probe targeting microRNA-155 in mice models]

OBJECTIVE

MicroRNA-155 (miR-155) is significantly highly expressed in breast cancer, lung cancer, liver cancer and other malignant tumors. This study was to design and construct a radiolabeled probe targeting miR-155 for in vivo imaging in breast cancer.

METHODS

Anti-miR-155 oligonucleotide (AMO-155) was chemically synthesized with 2' OMe modification. Its 5' end was linked with acetyl amine group. After chelated with a bifunctional chelator NHS-MAG3, AMO-155 was radiolabeled with ^99mTc using stannous chloride. The serum stability was evaluated at cellular level. In vivo imaging was performed in MCF-7 tumor bearing mice after the administration of ^99mTc radiolabeled AMO-155 and scramble control probes, respectively. Furthermore, the blocked imaging of tumor bearing mice was obtained after the injection of unlabeled AMO-155 2 hours ahead. MCF-7 and MDA-MB-231 tumor bearing mice with different expression level of miR-155 were imaged, respectively. Quantitative real-time PCR (qRT-PCR) was used to identify the expression level of miR-155 in the bearing tumors.

RESULTS

^99mTc-AMO-155 was prepared with high radiolabeled efficiency (97%), radiochemical purity (greater than 98%), and radioactive specific activity (3.75 GBq/μg). ^99mTc-AMO-155 was stable in fresh human serum for 12 hours. After the administration via tail vein, ^99mTc-AMO-155 displayed significant accumulation in MCF-7 bearing tumors with high expression level of miR-155, whereas ^99mTc-control showed little accumulation. After blocked with unlabeled AMO-155, the tumor could not be visualized clearly after the administration of ^99mTc-AMO-155. Furthermore, ^99mTc-AMO-155 could show the differential expression of miR-155 in vivo. MCF-7 tumor was shown with significantly higher radioactive accumulation than MDA-MB-231, based on its higher expression level of miR-155, which was verified by qRT-PCR.

CONCLUSION

^99mTc-labeled AMO-155 with chemical modification showed good serum stability and in vivo tumor targeting ability. This study provides a potential probe for in vivo imaging of breast cancer.