Human and porcine aortic valve endothelial and interstitial cell isolation and characterization

Background

Calcific aortic valve stenosis (AVS) is defined by pathological changes in the aortic valve (AV) and their predominant cell types: valvular interstitial (VICs) and endothelial cells (VECs). Understanding the cellular and molecular mechanisms of this disease is a prerequisite to identify potential pharmacological treatment strategies. In this study, we present a unique aortic valve cell isolation technique to acquire specific human and porcine cell populations and compared VICs and VECs of these species with each other for the first time.

Methods

AV cells were isolated from tissue obtained from human patients undergoing surgical aortic valve replacement (SAVR) or from porcine hearts. Functional analysis and in vitro experiments revealed that endothelial-to-mesenchymal transition (EndMT) can be induced in hVECs, leading to a significant increase in mesenchymal markers. In vitro calcification experiments of VICs demonstrated pronounced expression of calcification markers and visible calcific deposits in Alizarin Red staining in both species after incubation with pro-calcific media.

Results

Cells isolated from patient-derived AVs showed mesenchymal and endothelial-specific gene signatures (VIC and VEC, respectively). For instance, von Willebrand factor (vWF) and platelet endothelial adhesion molecule-1 (PECAM1) were upregulated in VECs, while the myofibroblastic markers alpha-smooth muscle actin (α-SMA) and vimentin (VIM) were downregulated in VECs compared to VICs. Analysis of cell function by migration revealed that VECs are more migratory than VICs. Induction of EndMT in vitro in VECs displayed increased expression of EndMT markers and decreased expression of endothelial markers, confirming their mesenchymal transdifferentiation ability. In vitro calcification of VICs revealed upregulation of alkaline phosphatase (ALPL), a hallmark of calcification. In addition, other calcification-related genes such as osteocalcin (BGLAP) and runt-related factor 2 (RUNX2) were upregulated. Alizarin red staining of calcified cells provided a further layer of confirmation that the isolated cells were VICs with osteoblastic differentiation capacity.

Conclusion

This study aims to take a first step towards standardizing a reproducible isolation technique for specific human and porcine VEC and VIC populations. A comparison of human and porcine aortic valve cells demonstrated that porcine cells may serve as an alternative cellular model system in settings where human tissue is difficult to obtain.

Infective endocarditis and stroke: when does it bleed? A single center retrospective study

BACKGROUND

Infective endocarditis (IE) is a serious condition with a high mortality, represents a rare cause of stroke and an increased risk of intracranial hemorrhage. In this single center study, we characterize stroke patients with IE. We were interested in risk factors for intracranial hemorrhage and outcome of patients with intracranial hemorrhage compared to patients with ischemic stroke.

METHODS

Patients with IE and symptomatic ischemic stroke or intracranial hemorrhage admitted to our hospital between January 2019 and December 2022 were included in this retrospective study.

RESULTS

48 patients with IE and ischemic stroke or intracranial hemorrhage were identified. 37 patients were diagnosed with ischemic stroke, 11 patients were diagnosed with intracranial hemorrhage. The intracranial hemorrhage occurred within the first 12 days after admission. We identified Staphylococcus aureus detection and thrombocytopenia as risk factors for hemorrhagic complications. An increased in-hospital mortality in patients with intracranial hemorrhage (63.6% vs. 22%, p = 0.022) was found, whereas patients with ischemic stroke and patients with intracranial hemorrhage do not differ regarding favorable clinical outcome (27% vs. 27.3%, p = 1.0). 27.3% patients with intracranial hemorrhage and 43.2% patients with ischemic stroke underwent cardiac surgery. Overall, 15.7% new ischemic strokes occurred after valve reconstruction, whereas no new intracranial hemorrhage was observed.

CONCLUSIONS

We found an increased in-hospital mortality in patients with intracranial hemorrhage. Beside thrombocytopenia, we identified S. aureus detection as a risk factor for intracranial hemorrhage.

Prognostic impact of acute kidney injury following tricuspid transcatheter edge-to-edge repair

Background

A considerable risk of acute kidney injury (AKI) following transcatheter interventions without iodinated contrast agents has also been recognized; however, little is known about the incidence and clinical relevance of post-procedural AKI in patients undergoing transcatheter edge-to-edge repair (TEER) for tricuspid regurgitation (TR).

Purpose

This study aimed to investigate the prognostic impact and predictors of post-procedural AKI following TEER for TR.

Methods

We retrospectively analyzed 218 consecutive patients who underwent TEER for TR. Post-procedural AKI was defined as an increase in serum creatinine of ≥0.3 mg/dl within 48 hours or of ≥50% within seven days after the procedure, compared to baseline. Procedural success was defined as at least one grade reduction in TR severity upon discharge. We determined the association between post-procedural AKI and the composite outcome consisting of all-cause mortality and re-hospitalization due to heart failure within one year after the procedure.

Results

Overall, the mean age of the patients was 79±7 years, and 46.3% of the patients were male. Post-procedural AKI occurred in 32 patients (14.7%) (Figure 1). Among baseline characteristics, male sex and an estimated glomerular filtration rate of <60 ml/min/m2 were associated with the occurrence of AKI. In addition, patients without procedural success had a higher incidence of post-procedural AKI (30.4% vs. 1.8%; p=0.024).

Patients with AKI had a higher incidence of in-hospital mortality compared to those without AKI (12.5% vs. 1.1%; p=0.005). Moreover, AKI was associated with the incidence of the composite outcome within one year after TEER for TR (adjusted hazard ratio: 2.06; 95% confidence interval: 1.11–3.84; p=0.023). In addition, our restricted cubic spline curve showed that a post-procedural increase in the creatinine level within seven days after the procedure was associated with a linear trend of the risk of the composite outcome after TEER (Figure 2).

Conclusions

Post-procedural AKI occurred in 14.7% of patients undergoing TEER for TR, despite the absence of iodinated contrast agents, which was associated with worse clinical outcomes. Male sex and CKD at baseline were related to the occurrence of AKI, and the procedural success of TEER was associated with a lower incidence of AKI. Our findings highlight the clinical impact of AKI following TEER for TR and should help with identifying patients at high risk of AKI.

Funding Acknowledgement

Type of funding sources: None.

Effectiveness of transcatheter edge-to-edge repair for atrial secondary mitral regurgitation

Background

Atrial secondary mitral regurgitation (ASMR) is a subtype of SMR that is characterized by normal left ventricular (LV) function, an enlarged left atrium and mitral annulus, and flattened leaflets. This anatomical feature is different from ventricular SMR (VSMR) and might therefore impact the procedural results of transcatheter edge-to-edge repair (TEER). The effectiveness and durability of TEER in patients with ASMR has not yet been well-studied.

Purpose

This study aimed to investigate the effectiveness of TEER and anatomical characteristics related to optimal MR reduction in patients with ASMR.

Methods

We retrospectively analyzed consecutive patients who underwent MitraClip at our institution. ASMR was defined as cases that met all of the following criteria: 1) normal mitral leaflets without organic disorder, 2) LV ejection fraction >50%, and 3) absence of LV enlargement and segmental abnormality. The primary outcome measure was MR reduction to ≤1+, and its predictors were explored in a logistic regression analysis. Leaflet-to-annulus index (LAI) was measured using the mid-esophageal long-axis view in the A2-P2 segment as follows: (anterior leaflet length + posterior leaflet length) / anteroposterior length of the mitral annulus.

Results

Among 415 patients with SMR, 118 patients met the criteria for ASMR (mean age: 80±8 years; male: 39.8%) (Figure 1). Patients with ASMR had a larger mitral annulus diameter, shorter mobile posterior leaflet length, and smaller coaptation depth compared to those with VSMR.

The technical success rate was 90.7%, and the MR reduction to ≤1+ after TEER was achieved in 94 (79.7%) patients with ASMR, which was comparable with VSMR. The in-hospital mortality rate was 2.5%. In multivariable logistic analysis, a large left-atrial (LA) volume index and a low LAI were associated with a lower rate of MR reduction to ≤1+ after TEER for ASMR (odds ratio [OR]: 0.98; 95% confidence interval [CI]: 0.97–0.99, and OR per 0.1 increase: 1.98; 95% CI: 1.13–3.45, respectively). The combined assessment of the LA volume index and LAI stratified the risk of residual MR ≥2+ after TEER (Figure 2).

In addition, the use of a newer generation of the MitraClip systems (NTR/XTR or G4 systems) was associated with a higher rate of MR reduction to ≤1+ compared to older generations (OR: 4.65; 95% CI: 1.67–13.00).

Conclusions

TEER with the MitraClip system achieved a high rate of MR reduction to ≤1+ in patients with ASMR. Furthermore, the new generations of the MitraClip system may provide a more effective reduction in ASMR. Although our findings suggest that TEER with the MitraClip system is a safe and feasible approach in patients with ASMR, the combined assessment of the LA volume index and LAI might be useful to refine the device selection for transcatheter mitral valve treatment in this subgroup of SMR patients.

Funding Acknowledgement

Type of funding sources: None.

Novel assay for quantifying the cholesterol crystal dissolution capacity of serum predicts outcomes in patients with severe aortic stenosis undergoing TAVR

Background

Aortic stenosis (AS) is the most common valvular heart disease (VHD) in developed countries. The pathophysiology of calcific AS has several clinical and pathobiological findings in common with atherosclerosis including chronic inflammation and lipoprotein deposition. Histopathological examination has revealed atherosclerosis-like lesions, that mainly contain cholesterol crystals (CC) in resected calcific aortic valve cusps. Previous studies have demonstrated that CCs can activate the NLRP3 inflammasome, resulting in an IL-1 driven systemic inflammation, that leads to the development of atherosclerotic plaques.

Purpose

In this study, we sought to validate a novel assay for measuring the serum capacity to dissolve cholesterol crystals (CCDC) in patients with AS and to examine whether this biomarker may be associated with clinical outcomes.

Methods

Our study cohort included 348 patients with AS undergoing transcatheter aortic valve replacement. The CCDC was measured using flow cytometry to enumerate CC, that were added to a 50% serum solution, at baseline and after two hours of incubation. The dissolution capacity was indicated as percentage change in CC count at baseline and after incubation. The study cohort was stratified according to the median CCDC into high and low CC dissolvers.

Results

The study population was 47.7% female and had a mean age of 80.9±6.2 years. The primary end point, a composite of one-year all-cause mortality and major vascular complication occurred less frequently in the high CCDC group (7.0%) as compared with the low CCDC group (15.3%, p=0.01). This was mainly driven by lower rates of one-year mortality in patients with a high CCDC (7.0% vs 13.6%, p=0.05), as presented in Figure 1. Furthermore, unplanned endovascular interventions were significantly less frequent in high CC dissolvers in contrast to low CC dissolvers (12.2% vs 20.5%, p=0.04). Although LDL cholesterol (101.8±37.3 mg/dL vs 97.9±37.6 mg/dL, p=0.35) and total cholesterol levels (158.1±43.8 mg/dL vs 154.1±40.2, p=0.41) were comparable in the high and low CCDC group, only patients with a low CCDC showed a benefit from statin treatment (Figure 2). In multivariate analysis, only low CCDC (OR: 2.51 [95% CI: 1.02–6.15], p=0.05) and Albumin (OR: 0.88 [95% CI: 0.79–0.98], p=0.03) were independently associated with one-year all-cause mortality

Conclusion

The CCDC is a novel biomarker associated with clinical outcome in patients with AS undergoing TAVR. It may provide new insights into patient's preventative anti-inflammatory capacity and additional prognostic information to identify vulnerable patients beyond classic risk assessment.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation).

Loss of ceramide synthase 5 reduces the development of aortic valve stenosis in mice with high fat diet

Background

Ceramide synthase 5 (CerS5) is essential to maintain C:16 ceramide levels in mice. Ceramides contribute to inflammation and calcification, two hallmarks of aortic valve stenosis development. It is known, that loss of CerS5 function reduces diet-induced obesity.

Purpose

The aim of this study was to investigate the effect of ceramide synthase 5 and high-fat diet on the development of aortic valve stenosis with a mouse model.

Methods

Our experiment consists of four groups of mice: Wild type (WT) and CerS5 (−/−) mice, with normal and high fat diet. We induced the aortic valve stenosis development through a wire-injury. For this model, a coronary angiography wire is introduced into the left ventricle over the right carotid artery, followed by rotation on the aortic valve level to generate a defined injury. Development of aortic valve stenosis was determined by measuring the peak velocity 14, 28 and 42 days after the wire-injury. With histological analysis of the aortic valve, we measured macrophage infiltration with CD68 immunostaining and calcification using von Kossa staining. For statistical analysis ANOVA and Turkeys multiple comparisons were performed.

Results

Histological analysis of the aortic valve revealed, that in CerS5 (−/−) mice with high fat diet (HFD) immune cell infiltration is reduced, while there is no difference between CerS5 (−/−) mice and wild type, when fed with normal diet (A). Also calcification showed a trend towards a reduction in CerS5 mice with high fat diet, but was not statistically significant (B). Echocardiography could detect a reduced peak velocity of CerS5 mice with high fat diet, in comparison to the other groups, four and six weeks after wire injury (C).

Conclusion

Our experiments indicate that loss of CerS5 function reduces the development of aortic valve stenosis in mice with high fat diet, by decreasing immune cell infiltration and calcification. Interestingly, in the groups with normal chow, loss of CerS5 function had no effect. In addition, high-fat diet alone had no negative effect in our mouse model. Based on our results it can be assumed that upon high fat diet CerS5 mediates for pro-inflammatory effects in the aortic valve, which are absent on normal diet.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Ernst & Berta Grimmke Foundation (13/19)

Characterization of the mitochondrial unfolded protein response in human coronary artery endothelial cells

Background

The unfolded protein response of the endoplasmic reticulum (UPRER) is highly activated in cardiovascular diseases and aims to restore homeostasis by improving protein folding. An analogue cytoprotective mitochondrial unfolded protein response (UPRMito) regulated by an orthologue of the activating transcription factor 5 (ATF5) was described in model organism c. elegans. However, in humans it is not clear if there is a distinct UPRMito, and if there is an activation of an UPRMito during stress induced by cardiovascular diseases. The endothelium is subjected to high levels of mitochondrial stress, e.g. in atherosclerosis.

Purpose

To provide a systematic characterization of the UPRMito in human coronary artery endothelial cells (HCAEC).

Methods and results

HCAEC were treated with Nicotinamide Riboside (NR), a NAD+ precursor that activates UPRMito without inducing cellular stress. NR treatment did not induce toxicity and improved cell viability at a concentration of 100μM NR. Quantitative PCR confirmed a dose-dependent upregulation of UPRMito markers. Additionally, we measured expression of ATF4, which is discussed to regulate an integrated stress response in mammals by activating both the UPRMito and UPRER. ATF4 upregulation upon NR treatment was more pronounced than ATF5 upregulation. Analysis of GTEX-Data showed that ATF5 is almost exclusively expressed in liver tissue, while ATF4 shows ubiquitous expression. Among 54 tissues, aortic tissue and coronary arterial tissue are among the five tissues with the highest ATF4 expression.

Analysis of RNA-seq-data of human carotid atherosclerosis revealed that the two transcription factors are differentially regulated. ATF4 is downregulated in unstable plaque, while ATF5 is upregulated. Moreover, ATF4 is in both conditions highly more abundant than ATF5. Accordingly, endothelial cells incubated under atherosclerotic conditions (oxLDL + high glucose) exhibited a ATF4 down- and ATF5 upregulation. Genes previously described to be involved in the UPRMito exhibited a similar expression pattern as ATF4.

To further elucidate these findings, we will perform transcriptomic analyses of HCAEC treated with atherosclerotic stimuli (IL-1β, oxLDL), UPRER inductors (Thapsigargin, Tunicamycin) and stressors of mitochondrial proteostasis (Oligomycin, MitoBloCK-6), to analyze, if ATF5- or ATF4-related pathways are dysregulated. Specific inhibitors and UPRMito activators will be used to investigate the significance of ATF4 and ATF5 on endothelial cell function (proliferation, migration, apoptosis, monocyte adhesion).

Conclusion

The UPRMito is dysregulated during the pathogenesis of atherosclerosis in HCAEC. Further findings are required to elucidate, if the UPRMito is activated separately and specifically by ATF5 or as part of an integrated cellular stress response by ATF4. A deeper understanding of these stress responses is crucial for the identification of novel therapeutic targets in atherosclerosis.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): University hospital Bonn

Serum levels of the endoplasmic-reticulum-stress chaperone GRP78 identify patients with coronary artery disease and predict mortality

Background

Endoplasmic-reticulum-stress (ER Stress) and associated chaperones like the main ER-Stress moderator GRP78 (glucose-regulated-protein, 78kDa) are involved in the pathogenesis of coronary artery disease (CAD). In addition to their intracellular localization and effects, secretion and extracellular properties of chaperones, including GRP78, were recently described. However, a diagnostic or prognostic relevance of serum ER-chaperones in patients with CAD has not been established yet.

Purpose

To investigate the significance of serum GRP78 in patients undergoing coronary angiography for suspected CAD.

Methods

Serum concentration of GRP78 was measured by ELISA in 789 patients with indication for coronary angiography (both ACS and CCS). CAD was defined as >50% stenosis in any major coronary artery. Clinical endpoint was one-year all-cause mortality.

Results

Mean age was 70.8±11.9 years and 65% of patients were male. 192 (24%) patients presented with acute coronary syndrome (ACS). CAD was found in 72.4% of patients. Mean GRP78 serum concentration was 2492 ng/ml. Increased levels of GRP78 (> median) were associated with diabetes (29.9% vs. 23.1%, p=0.03), a higher BMI (28.9±7.1 kg/m2 vs. 27.0±6.0 kg/m2, p<0.0001) and chronic kidney disease (CKD: 23.3% vs. 17.1%, p=0.03). There was no difference regarding age or sex.

GRP78 levels were increased in patients with CAD when compared to patients without CAD (2640 ng/ml [95% CI: 2415–2864] vs. 2178 ng/ml [95% CI: 1893–2463], p=0.013, Fig A). Interestingly, GRP78 levels were lower in patients with ACS than in patients with CCS (2284 ng/ml [95% CI: 1944–2642] vs. 2822 [95% CI: 2531–3113], p=0.018, Fig B). To further elucidate these findings, we analyzed available proteomics of patients with hypertrophic cardiomyopathy undergoing septal ablation as a model for a planned myocardial infarction (PMI)1. Coronary sinus blood samples drawn 10 and 60 min after PMI showed a downregulation of GRP78 levels compared to baseline.

Finally, we assessed prognostic relevance of GRP78 in patients with CAD. Increased GRP78 levels were associated with lower one-year mortality (5.3% vs. 10.6% vs. p=0.016). Increased GRP78 levels were associated with reduced one-year mortality in both continuous (HR: 0.48 [95% CI: 0.25–0.92]) and categorial analyses stratified by median GRP78. After adjusting for age, sex, BMI, diabetes, CKD and ACS, GRP78 remained an independent predictor of one-year mortality (HR: 0.51 [0.26–0.96], p=0.039).

Conclusion

GRP78 serum levels are generally elevated in patients with CAD but downregulated during ACS. Reduced levels are associated with increased one-year mortality. These results support previous findings that GRP78 secretion is a protective mechanism in cardiovascular diseases. Further mechanistic studies are warranted to foster our understanding of the effects of extracellular GRP78 and to aid in the identification of modifying therapeutic targets.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): University hospital Bonn

The endoplasmic reticulum (ER) chaperone GRP78 is secreted during ER Stress and alleviates endothelial cell inflammation

Introduction

Glucose-Regulated Protein 78kD (GRP78) is a chaperone and the main regulator of the ER-stress response. Upon ER Stress, GRP78 activates the unfolded protein response (UPR), which aims to clear unfolded proteins and restore ER homeostasis. A prolonged activation of the UPR triggers inflammation, thus contributing to the progression of cardiovascular diseases. Recently, extracellular secretion of GRP78 was described. However, the pathophysiological relevance of secreted GRP78 in atherosclerosis and endothelial cell inflammation remains to be elucidated.

Aim

Aim of this study is to investigate the role of GRP78 secretion in endothelial cells.

Methods and results

First, we sought to investigate if vascular cells secrete GRP78 during ER Stress. Human coronary artery endothelial cells (HCAEC) were treated with the ER stress inductor tunicamycin for up to 48h. After ER Stress induction, Western Blot and ELISA experiments detected an increased intracellular GRP78 expression. Intriguingly, prolonged ER Stress also promoted extracellular secretion of GRP78. Proteomic analysis confirmed that after ER-Stress induction, GRP78 is one of the most highly upregulated extracellular proteins (2.43-fold). Co-incubation with Brefeldin A, an inhibitor of ER-Golgi protein transport, abolished extracellular secretion (Fig.1). Hence, ER-Stress-induced GRP78 secretion is an actively regulated process.

Next, the effect of GRP78 containing conditioned medium (CM) on HCAEC was analyzed. Treatment with GRP78 containing CM decreased GRP78 mRNA expression in target cells (0.35-fold vs. control [+BFA], p<0.0001). Furthermore, it increased viability (93.0% vs. 79.6%, p=0.017) and decreased formation of reactive oxygen species (0.78-fold). Moreover, expression of markers of vascular inflammation and ER Stress (e.g., NF-κB and CHOP) was decreased when compared to control CM with additional BFA treatment.

However, ER Stress induced by tunicamycin exhibits deleterious effects on donor cells and is therefore not feasible for in vivo usage. Thus, we utilized Bip protein inducer x (Bix), a recently described small-molecule activator of GRP78. Treatment with Bix also promoted expression of GRP78 and general UPR activation (e.g., ATF4, XBP1). Moreover, in contrast to tunicamycin, Bix treatment did not impair viability of HCAEC.

After treatment with Bix-induced CM, apoptosis (0.77-fold vs. 1.64-fold, p<0.0001) and expression of markers of vascular inflammation (e.g., Il-6) were significantly decreased compared to control CM. Furthermore, presence of GRP78 was able to promote proliferation and viability.

Conclusion

Endothelial ER Stress promotes GRP78 secretion. Presence of GRP78 in conditioned medium ameliorates subsequent ER Stress and endothelial inflammation, which play a critical role in atherogenesis. Modification of GRP78 secretion by Bix might be a feasible and innovative therapeutic option for vascular inflammation and endothelial regeneration.

Funding Acknowledgement

Type of funding sources: None.

Unravelling the role of SOCS3 in aortic valve stenosis

Background

Calcific aortic valve stenosis (CAVD) is the most prevalent heart valve disease worldwide and, in advanced stages, leads to clinical deterioration and poor prognosis. Until now, no medical treatment is available. Thought to be a merely degenerative disease, we now know that disease initiation and progression are actively regulated by immune cell infiltration, chronic inflammation, osteogenic differentiation of valvular interstitial cells (VIC) and endothelial-to-mesenchymal transition (EndMT) of valvular endothelial cells (VEC). Suppressor of Cytokine Signaling 3 (SOCS3) is known to be a key regulator of inflammation. It promotes the polarisation of macrophages to an inflammatory phenotype and thus, contributes to disease progression in atherosclerosis. In CAVD, not only inflammation but also heterotopic bone formation leads to the thickening and obstruction of the aortic valve cusps and as SOCS3 is one of the main regulators of physiological bone formation, it could play a critical role in the progression of CAVD.

Purpose

We hypothesize that SOCS3 plays a crucial role during calcification of the aortic valve through regulation of EndMT, calcification of valvular interstitial cells and macrophage polarization.

Methods and results

In initial screening experiments, we investigated SOCS3-protein expression in explanted human aortic valves from patients undergoing surgical aortic valve replacement. SOCS3 is expressed in both stenotic and non-stenotic valve tissues. Immunofluorescence-staining of human aortic valves shows the co-localisation of SOCS3 with the interstitial cell-marker Vimentin and SOCS1, which is known to regulate macrophage-polarisation together with SOCS3 (Fig. 1). Staining of the macrophage-marker CD68 revealed its co-localisation with calcified areas of the aortic valve cusp. We validated our findings in our in vitro model of VIC calcification using two different calcifying conditions. Upregulation of RUNX2 and BMP2 verified successful osteogenic differentiation of VICs. During osteogenic differentiation for 7 days, SOCS3 and SOCS1 are significantly upregulated (Fig. 2A).

We were able to induce EndMT by stimulating VEC with either TNFα or TGFβ/IL1β in vitro. We show that EndMT leads to the loss of endothelial cell markers like eNOS and VWF and to an upregulation of interstitial cell markers (such as Vimentin and α-SMA) and markers of EndMT (SNAI2). During EndMT, we were also able to observe a significant upregulation of SOCS1 and SOCS3 after 7 days (Fig. 2B). Ongoing knockdown experiments will help to elucidate the role of SOCS1 and SOCS3 during initiation and progression of CAVD.

Conclusion

We aim towards a better understanding of SOCS3 and its role in inflammation and calcification as hallmarks of the pathogenesis of CAVD. Since Zoledronic acid has been shown to induce a decreased expression of SOCS3 in macrophages, this might present as a possible treatment strategy to target SOCS3 therapeutically.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Deutsche Forschungsgemeinschaft

LXR-beta signalling is a key mediator in the pathogenesis of aortic valve stenosis and its prevention by saringosterol

Background

Cholesterol metabolism contributes as a risk factor for aortic valve stenosis (AS), but pharmacological approaches remained unsatisfying. The liver-X-receptor (LXR) is a key regulator in cholesterol metabolism, though its clinical use is limited due to unwanted side effects. The seaweed-derived oxysterol saringosterol is an agonist of the LXRβ, promising a more favourable tolerability.

Purpose

This study aimed to better understand the pathophysiology of aortic valve stenosis and to assess the potential of saringosterol as a targeted pharmacotherapy.

Methods

Tissue samples from aortic valves were collected from patients with AS or aortic valve regurgitation (AR). Transcriptomics were performed and gene ontology (GO) analysis was used to determine pathways and genes that are relevant to AS, and then validated using qPCR.

In vivo, mice received a wire-induced aortic valve stenosis and were either fed a diet supplemented with saringosterol or control diet. Haemodynamic characteristics were assessed using echocardiography. Additionally, hepatic concentrations of saringosterol, expression of LXRβ regulated genes as well as aortic valve thickness and composition were assessed.

In vitro, human aortic valve interstitial cells (VIC) were cultured in a procalcifing medium and stimulated with saringosterol to investigate the underlying molecular mechanisms.

Results

Transcriptomic analysis of AS samples revealed the regulation of several GO-terms related to cholesterol- or lipid metabolism. Many of the genes identified were regulated by LXRβ, suggesting its pathophysiological relevance in AS. We validated this assumption by performing qPCR from aortic valves for the most prominent downstream targets of LXRβ, ABCA1 and ABCG1, with both being differentially regulated.

In vivo, treatment with saringosterol for six weeks resulted in a significant accumulation of saringosterol in liver tissue as well as induction of LXRβ-regulated genes. Furthermore, treatment with saringosterol strikingly reduced the development of AS after wire injury as assessed by echocardiographic and histological measurements.

In vitro, the differentiation of VIC into osteoblastic and myofibroblastic phenotypes was abolished by saringosterol, which reduced the expression of the procalcifying mediators RUNX-2 and ACTA-2 in a dose-dependent manner.

Conclusion

We identified LXRβ-signalling as a key regulator in the pathophysiology of AS. Transcriptomic analyses revealed that cholesterol metabolism was altered in human AS, and many of the genes involved were linked to the LXRβ. In a murine model, we demonstrated that oral application of saringosterol induced LXRβ-activity and mitigated the development of AS. In vitro experiments demonstrated that saringosterol prevents adverse cell differentiation of VIC, which provides a mechanistic explanation.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): BONFOR Universität Bonn

Right ventricular ejection fraction assessed by computed tomography in patients undergoing transcatheter tricuspid valve intervention

Background

The role of right-ventricular (RV) function in patients with tricuspid regurgitation (TR) undergoing transcatheter tricuspid valve interventions (TTVI) is poorly understood. Although cardiac computed tomography (CCT) provides elaborate three-dimensional (3D) visualization of the entire anatomy of the RV and theoretically allows to assess the global RV systolic function. Nevertheless, the utility of the functional assessments of the RV using CCT remains unclear in patients undergoing TTVI.

Purpose

This study investigated the association of right-ventricular ejection fraction (RVEF) assessed by CCT with clinical outcome in patients undergoing TTVI.

Methods

We retrospectively assessed 3D-RVEF by using pre-procedural CCT images in patients undergoing TTVI with either edge-to-edge repair or annuloplasty device. RV dysfunction (RVD) was defined as a CT-RVEF <45%. The primary outcome was a composite outcome, consisting of all-cause mortality and hospitalization due to heart failure, within one year after TTVI.

Results

Of 157 patients, 58 (36.9%) presented with CT-RVEF <45%. Patients with CT-RVEF <45% were more likely to be male, to have a previous history of coronary artery disease, and had higher EuroSCORE II and a lower LVEF compared to those with CT-RVEF ≥45%, while the severity of TR was comparable between the groups.

Among the patients with CT-RVEF <45%, acute procedural success was achieved in 93.1%, and in-hospital mortality was 1.7%, which were comparable to those with CT-RVEF ≥45%.

Patients with CT-RVEF <45% had an improvement in New York Heart Association functional class at follow-up compared to baseline; however, CT-RVEF <45% was associated with a higher risk of the composite outcome (adjusted hazard ratio: 3.23; 95% confidence interval: 1.52–6.88; p=0.002) (Figure 1). Furthermore, CT-RVEF had an additional value to stratify the risk of the composite outcome beyond two-dimensional transthoracic echocardiographic (TTE) assessments (Figure 2).

In addition, patients with CT-RVEF <45% exhibited an attenuated association between a reduction in TR to <3+ and a lower incidence of the composite outcome after TTVI compared to those with CT-RVEF ≥45%.

Conclusions

TTVI is safe and feasible regardless of baseline RV function, while RVD, defined as 3D-RVEF <45%, is associated with a higher risk of the composite outcomes within one year after TTVI. Furthermore, our findings suggest that the prognostic benefits of TR reduction might be attenuated in patients with RVD. Given the additional prognostic value of CT-RVEF to the conventional echocardiographic assessments, the assessments of 3D-RVEF with CCT may refine the patient selection for TTVI.

Funding Acknowledgement

Type of funding sources: None.

Refining the accuracy of right ventricular-pulmonary arterial coupling in patients undergoing transcatheter tricuspid valve treatment

Background

Assessing right-ventricular (RV) function is paramount for risk stratification but remains challenging in patients with TR. RV-pulmonary artery (PA) coupling seems more feasible for the assessment of RV function.

Methods

We assessed RV-PA coupling by the ratio of TAPSE and PASP at baseline, in which PASP was measured both by echocardiography (ePASP) and invasively using a right-heart catheter (iPASP). We also assessed the RV fractional-area change (RVFAC) as measured by transthoracic echocardiography. Participants for the present study comprised patients undergoing TTVR from June 2015 to July 2021 at the University Hospital of Bonn. Patients lacking either echocardiographic or invasive measurements for the assessment of RV-PA coupling were excluded from the analysis. The outcome was defined as a composite of mortality and rehospitalization due to heart failure within one year after the procedure.

Results

A total of 206 patients were included in the present analysis. The participants were at an advanced age (78.5±7.1 years), predominantly female (58.3%), and at a high risk for surgery (EuroSCORE II: 7.4±4.8%). Massive/torrential TR was observed in 100 of these patients. With the median follow-up duration of 201 days (interquartile range 98–424 days), the outcome occurred in 57 patients. Compared to TAPSE/ePASP, TAPSE/iPASP showed better predictability for the outcome: the AUCs were 0.582 for TAPSE/ePASP and increased to 0.714 when iPASP was applied to the formula (i.e. TAPSE/iPASP). The trend was also true for RV-PA coupling using RVFAC (AUCs: 0.561 for RVFAC/ePASP, 0.693 for RVFAC/iPASP). There was a significant correlation between ePASP and iPASP, whereas the correlation was attenuated in patients with TR beyond severe (i.e. massive/torrential TR) (interaction p = 0.01). In addition, a semiquantitative echocardiographic estimation of right atrial (RA) pressure was not correlated with the invasive measurement.

Conclusion

The present analysis confirms that RV-PA coupling, measured as TAPSE/PASP, is a powerful predictor of mortality and rehospitalization due to heart failure in patients undergoing TTVR. The predictability is even more improved if PA pressure is measured invasively and applied to the formulas.

Funding Acknowledgement

Type of funding sources: None.

Optimal protamine-to-heparin dosing ratio for the prevention of bleeding complications in patients undergoing TAVR – a multicentre experience

Background

Despite major advances, transcatheter aortic valve replacement (TAVR) is associated with procedure-related vascular and bleeding complications, that have a significant impact on mortality. A recently published study has shown that heparin antagonization using protamine resulted in significantly lower rates of serious bleeding events in patients undergoing TAVR as compared to those without heparin reversal. However, the optimal protamine-to-heparin dosing ratio to prevent bleeding complications without increasing ischemic complications in patients undergoing TAVR is unknown. Accordingly, daily clinical practice varies between selective to routine administration of protamine in different dosing ratios.

Purpose

The aim of this observational multicentre study was to compare the safety and efficacy of two different protamine-to-heparin dosing ratios for the prevention of bleeding complications after TAVR.

Methods

The study included 1446 patients undergoing TAVR, of whom 623 (43.1%) received partial and 823 (56.9%) full heparin antagonization (0.4–0.6 mg versus 0.9–1.0 mg protamine/100 units of heparin). The indication for partial or full heparin antagonization was left to the discretion of the operator, who made the decision according to the patient's individual thrombotic and bleeding risk. The primary endpoint was a composite of 30-day mortality, life-threatening and major bleeding. Safety endpoints included stroke and myocardial infarction at 30 days.

Results

The overall study population had a mean age of 81.1±6.0 years; 47.9% were of female gender.

The baseline characteristics were well balanced between the two groups. Full antagonization of heparin resulted in significantly lower rates of the primary endpoint as compared to partial heparin reversal (5.6 vs. 10.4%, p<0.01), mainly driven by lower rates of life-threatening (0.5 vs 1.6%, p=0.05) and major bleeding (3.2 vs 7.5%, p<0.01). The incidence of major vascular complications was significantly lower in patients with full heparin reversal (3.5 vs 7.5%, p<0.01), as presented in Figure 1. Accordingly, the post-interventional drop in hemoglobin level and the need for red-blood-cell transfusion was lower in patients receiving full as compared to partial heparin reversal (1.5±1.2 vs 1.7±1.2 g/dl, p<0.01; 10.4 vs 15.9%, p<0.01, respectively). Regarding safety endpoints, no differences were observed in the incidence of stroke and myocardial infarction between the groups (2.2 vs 2.6%, p=0.73 and 0.2 vs 0.4%, p=0.64, respectively). Multivariate regression analyses revealed that full antagonization of heparin (OR: 0.43 [95% CI: 0.24–0.81], p<0.01) was independently associated with the primary end point

Conclusion

Full heparin antagonization resulted in significantly lower rates of life-threatening and major bleeding after TAVR as compared to partial heparin reversal. The occurrence of stroke and myocardial infarction was low and comparable between both groups.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation).

High volume retrograde portography for better discrimination of the portal vein during TIPS procedure

Background: Imaging of the portal vein prior to puncture for TIPS is essential.

Purpose: With this study, we examined a modified retrograde portography with regard to the reliable representation of the portal vein.

Material and Methods: Prospective evaluation of 65 TIPS interventions with regard to the delimitation of the portal vein and the exact parameters of retrograde portography such as catheter diameter and contrast medium volume per injection.

Results: Retrograde portographies with a large-lumen catheter (10 F) and a large contrast medium volume (40 mL) were performed in 35/63 patients with significantly better delineation of the portal vein than when using 5 F catheters with 10 mL contrast medium.

Conclusion: The so-called high volume retrograde portography leads to better delimitation of the portal vein during TIPS application.

Impact of leaflet-to-annulus index on residual tricuspid regurgitation following transcatheter edge-to-edge tricuspid valve repair

Introduction

Edge-to-edge transcatheter tricuspid valve repair (TTVR) is a promising treatment option for tricuspid regurgitation (TR), and it is required to identify anatomical parameters to predict the procedural success of TTVR.

Purpose

In this study, we assessed leaflet-to-annulus index (LAI), a simple tool to evaluate the remodeling of tricuspid annulus in relation to the leaflets, and investigated the association of the LAI with residual TR after edge-to-edge TTVR.

Methods

Consecutive 140 patients with symptomatic TR who underwent edge-to-edge TTVR from June 2015 to July 2020 were enrolled. The LAI was calculated using preprocedural transesophageal echocardiography and was defined as follows: (anterior leaflet length + septal leaflet length)/anteroseptal tricuspid annulus diameter (Figure 1). Primary outcome was residual TR ≥3+ at discharge, and patients were allocated into two groups as follows: residual TR ≥3+ and <3+. Secondary outcome was the composite outcome, consisting of all-cause mortality and heart failure hospitalization, within one year after TTVR.

Results

Of the 140 patients, 43 patients had residual TR ≥3+ after TTVR. The patients with residual TR ≥3+ had lower LAI compared to those with residual TR <3+ (1.06±0.10 vs. 1.13±0.09; p=0.001). Multivariable analysis revealed that LAI was associated with residual TR ≥3+ (odds ratio [by 0.1 increase]: 0.57; 95% confidence interval [95% CI]: 0.35–0.94; p=0.02), independently of baseline TR severity, location of TR jet, and coaptation gap size (Table 1). Patients with residual TR ≥3+ had a higher incidence of the composite outcome within one year after TTVR (34.9% vs. 18.6%; log-rank p=0.04) and residual TR ≥3+ was an independent predictor of the composite outcome within one year (hazard ratio: 2.04; 95% CI: 1.01–4.11; p=0.04).

Conclusion

Lower LAI is associated with residual TR ≥3+ after edge-to-edge TTVR, which itself was a significant predictor of the one-year composite outcome. Our findings suggest that LAI is a useful tool to identify patients to be successfully treated with edge-to-edge TTVR.

Funding Acknowledgement

Type of funding sources: None. Figure 1Table 1

Circulating microRNA-122-5p correlates with improvement in left-ventricular function after transcatheter aortic valve replacement and regulates viability of cardiomyocytes via extracellular vesicles

 

Transcatheter aortic valve replacement (TAVR) is a well-established treatment option for high- and intermediate-risk patients with severe symptomatic aortic valve stenosis (AVS). However, a specific role for circulating microRNAs (miRNAs) in the improvement of cardiac function for patients after TAVR has not yet been investigated. Herein, we generally explored the differential expression of miRNAs in circulating extracellular vesicles (EV-miRNAs) in patients after TAVR and, in particular, the novel role of circulating miR-122-5p in cardiomyocytes.

Circulating EV-associated miRNAs were investigated by using an unbiased Taqman-based human miR array. Several EV-miRNAs (miR-122-5p, miR-26a, miR-192, miR-483-5p, miR-720, miR-885-5p, and miR-1274) were significantly deregulated in aortic stenosis patients at day seven after TAVR in comparison to the pre-procedural levels in patients without LVEF-improvement. The higher levels of miR-122 were negatively correlated with LVEF improvement at both day seven (r=−0.264 and p=0.015) and at six months (r=−0.328 and p=0.0018) after TAVR. At the three-year follow-up, patients with a higher level of miR-122-5p displayed significantly increased cardiovascular mortality (p=0.03). By utilization of patient-derived samples and a murine aortic-stenosis model, we observed that the expression of miR-122-5p correlates negatively with cardiac function, which is associated with LVEF. Graded wire-injury-induced aortic-valve-stenotic mice demonstrated a higher level of miR-122-5p, which was related to cardiomyocyte dysfunction. Murine ex vivo experiments revealed that miR-122-5p is highly enriched in endothelial cells in comparison to cardiomyocytes. Co-culture experiments with endothelial cells and cardiomyocytes, copy-number analysis, fluorescence microscopy with Cy3-labeled miR-122-5p demonstrated that miR-122-5p can be shuttled via large extracellular vesicles from endothelial cells into cardiomyocytes. Gain- and loss-of-function experiments suggested that EV-mediated shuttling of miR-122-5p increases the level of miR-122-5p in recipient cardiomyocytes and regulates viability of the cardiomyocytes. In silico prediction and mass spectrometry were used to search for binding partners of miR-122-5p. Mechanistically, miR pulldown, electrophoretic mobility shift assay, and RNA immunoprecipitation confirmed that miR-122-5p interacts with an RNA-binding protein, hnRNPU, in a sequence-specific manner to encapsulate miR-122-5p into large EVs. Upon shuttling into recipient cells, miR-122-5p negatively regulates the expression of the anti-apoptotic gene BCL2, by binding to its 3' untranslated region to regulate its translation, and thereby decreasing the viability of target cardiomyocytes.

Increased levels of circulating pro-apoptotic EV-incorporated miR-122-5p is associated with reduced LVEF after TAVR. Extracellular vesicular shuttling of miR-122-5p regulates the viability and apoptosis of cardiomyocytes in a Bcl2-dependent manner.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): German Research Foundation (DFG); German Society of Cardiology (DGK)

Vitamin K epoxide reductase complex subunit 1-like 1 (VKORC1L1) inhibition induces a proliferative and pro-inflammatory vascular smooth muscle cell phenotype

Background

Vitamin K antagonists (VKA) like Warfarin are known to promote adverse cardiovascular remodelling. Contrarily, vitamin K supplementation has been discussed to decelerate cardiovascular disease. The recently described VKOR-isoenzyme Vitamin K epoxide reductase complex subunit 1-like 1 (VKORC1L1) is involved in vitamin K maintenance and exerts antioxidant properties. In this study, we sought to investigate the role of VKORC1L1 in neointima formation and on vascular smooth muscle cell (VSMC) function.

Methods and results

Treatment of wild-type mice with Warfarin increased maladaptive neointima formation after carotid artery injury. This was accompanied by reduced vascular mRNA expression of VKORC1L1.

In vitro, Warfarin was found to reduce VKORC1L1 mRNA expression in VSMC. VKORC1L1 downregulation by siRNA promoted viability, migration and formation of reactive oxygen species. VKORC1L1 knockdown further increased expression of key markers of vascular inflammation (NFκB, IL-6). Additionally, downregulation of the endoplasmic reticulum (ER) membrane resident VKORC1L1 increased expression of the main ER Stress moderator, glucose-regulated protein 78 kDa (GRP78). Moreover, treatment with the ER Stress inducer Tunicamycin promoted VKORC1L1, but not VKORC1 expression.

Finally, we sought to investigate, if treatment with vitamin K can mediate the protective properties of VKORC1L1. Thus, we examined effects of menaquinone-7 (MK7) on VSMC phenotype switch. MK7 treatment dose-dependently alleviated PDGF-induced proliferation and migration. In addition, we detected a reduction in expression of inflammatory and ER Stress markers.

Conclusion

VKA-induced neointima formation is associated with reduced vascular VKORC1L1 expression. VKORC1L1 inhibition contributes to an adverse VSMC phenotype while MK7 restores VSMC function. Thus, MK7 supplementation might be a feasible therapeutic option to modulate vitamin K- and VKORC1L1-mediated vasculoprotection.

Funding Acknowledgement

Type of funding sources: None.

Widening the Indications for Intrasaccular Flow Disruption: WEB 17 in the Treatment of Aneurysm Locations Different from Those in the Good Clinical Practice Trials

BACKGROUND AND PURPOSE

The safety and efficacy of the Woven EndoBridge (WEB) device has been shown in multiple good clinical practice trials, whereas aneurysm locations in these trials were restricted to bifurcation aneurysms located at the circle of Willis (MCA bifurcation, ICA bifurcation, anterior communicating artery, basilar artery tip). Our aim was to evaluate angiographic and clinical results with the WEB 17 in aneurysm locations that were excluded from the good clinical practice trials, assuming that the angiographic and clinical results are similar to those of the good clinical practice trials for aneurysms in traditional locations.

MATERIALS AND METHODS

We performed retrospective analysis of immediate and follow-up results of aneurysms in locations outside the good clinical practice trials in which the WEB 17 was used on an intention-to-treat approach.

RESULTS

Between June 2017 and May 2020, forty-seven aneurysms in 44 patients met the inclusion criteria. Aneurysm locations were the ICA posterior communicating artery in 19 (40.3%), the ICA paraophthalmic or choroidal locations in 4 (8.6%), anterior cerebral artery A2 segment in 13 (27.7%), MCA M1 segment in 2 (4.3%), posterior cerebral artery P2 segment in 2 (4.3%), PICA in 3 (6.4%), and the superior cerebellar artery in 4 (8.4%) cases. The procedure-related morbidity and mortality rates in the entire series were 0.0%. The early and late (<12 and >12 months) complete occlusion rates were 63.9% (23/36) and 77.8% (14/18), respectively.

CONCLUSIONS

The WEB 17 is safe and effective in aneurysm locations different from the traditional bifurcation aneurysms included in the good clinical practice trials. Further studies will help to define the entire spectrum of aneurysm morphologies and locations suitable for the WEB 17.

Dissolving cholesterol crystals reduces aortic valve stenosis development in mice

Background

Aortic valve stenosis (AS) is the most common valve disease worldwide and is associated with a very high morbidity and mortality. Until today, aortic valve replacement is the only therapeutic option available. Analysis of explanted human aortic valves has shown that atherosclerosis-like lesions, that contain cholesterol crystals (CC), are present in stenotic aortic valve cusps. It has been demonstrated that CCs can activate the NLRP3 inflammasome and hereby trigger a complex, IL-1b driven, inflammatory response. 2-hydroxypropyl-β-cyclodextrin (CD) is a cyclic oligosaccharide that can increase the solubility of CCs, which results in a reduction of CC-load and therefore could inhibit the pro-inflammatory immune response.

Methods

Severe AS was induced in 10 weeks old C57BL/6-J (WT) and Apolipoprotein-E-deficient (ApoE) mice. Acoronary springwire was used to induce an endothelial injury under echocardiographic guidance. AS development was confirmed via ultrasound examinations. ApoE mice were fed a cholesterol-rich western diet and concomitantly received daily injections of 2g/kg/d CD via subcutaneous injection. CCs were visualized with laser reflection confocal microscopy. Serum cholesterol analysis were performed via mass GC-MS-SIM.

Results

In order to evaluate whether hyperlipidemia aggravates AS development, WT and ApoE mice were fed a cholesterol-rich diet and subjected to our model of wire-induced AS. Trans-aortic valve peak velocity levels of ApoE mice were significantly increased six weeks after injury compared to WT mice. Histological analysis of these mice showed large CC-deposits in the aortic valves of ApoE mice. Next, CC solubility was increased in a group of ApoE mice, control mice only received PBS injections. Interestingly, mice treated with CD displayed a significantly reduced peak blood velocity over the aortic valve compared to PBS mice. Left ventricular ejection fraction remained unchanged. Serum cholesterol analysis was performed to analyze the effect of CD on cholesterol metabolism. 27-hydroxycholesterol, an endogenous oxysterol of cholesterol metabolism, which reduces the potential for the conversion of free cholesterol into crystals was significantly increased in CD treated mice. The levels of cholesterol precursors were unchanged, indicating that CD doesn't influence de-novo synthesis of cholesterol. Intestinal absorption of cholesterol was also not affected by CD, as assessed by quantification of phytosterols in the serum of CD and PBS treated mice.

Conclusion

These results underline the importance of hyperlipidemia in the pathogenesis of AS. Particularly CCs seem to act as an important inflammatory trigger in the development of AS. Increasing the solubility of cholesterol through CD reduces AS development in mice and could, as it is already considered safe in human, act as a possible therapeutic option.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): DFG, German Research Foundation

Parameters predicting COVID-19-induced myocardial injury and mortality

Clinical manifestations of COVID-19 affect many organs, including the heart. Cardiovascular disease is a dominant comorbidity and prognostic factors predicting risk for critical courses are highly needed. Moreover, immunomechanisms underlying COVID-induced myocardial damage are poorly understood.

OBJECTIVE

To elucidate prognostic markers to identify patients at risk.

RESULTS

Only patients with pericardial effusion (PE) developed a severe disease course, and those who died could be identified by a high CD8/Treg/monocyte ratio. Ten out of 19 COVID-19 patients presented with PE, 7 (78%) of these had elevated APACHE-II mortality risk-score, requiring mechanical ventilation. At admission, PE patients showed signs of systemic and cardiac inflammation in NMR and impaired cardiac function as detected by transthoracic echocardiography (TTE), whereas parameters of myocardial injury e.g. high sensitive troponin-t (hs-TnT) were not yet increased. During the course of disease, hs-TnT rose in 8 of the PE-patients above 16 ng/l, 7 had to undergo ventilatory therapy and 4 of them died. FACS at admission showed in PE patients elevated frequencies of CD3⁺CD8⁺ T cells among all CD3+ T-cells, and lower frequencies of Tregs and CD14⁺HLA^-DR⁺-monocytes. A high CD8/Treg/monocyte ratio predicted a severe disease course in PE patients, and was associated with high serum levels of antiviral cytokines. By contrast, patients without PE and PE patients with a low CD8/Treg/monocyte ratio neither had to be intubated, nor died.

CONCLUSIONS

PE predicts cardiac injury in COVID-19 patients. Therefore, TTE should be performed at admission. Immunological parameters for dysfunctional antiviral immunity, such as the CD8/Treg/monocyte ratio used here, supports risk assessment by predicting poor prognosis.

Lanadelumab demonstrates rapid and sustained prevention of hereditary angioedema attacks

Background

Lanadelumab demonstrated efficacy in preventing hereditary angioedema (HAE) attacks in the phase 3 HELP Study.

Objective

To assess time to onset of effect and long‐term efficacy of lanadelumab, based on exploratory findings from the HELP Study.

Methods

Eligible patients with HAE type I/II received lanadelumab 150 mg every 4 weeks (q4wks), 300 mg q4wks, 300 mg q2wks, or placebo. Ad hoc analyses evaluated day 0‐69 findings using a Poisson regression model accounting for overdispersion. Least‐squares mean monthly HAE attack rate for lanadelumab was compared with placebo. Intrapatient comparisons for days 0‐69 versus steady state (days 70‐182) used a paired t test for continuous endpoints or Kappa statistics for categorical endpoints.

Results

One hundred twenty‐five patients were randomized and treated. During days 0‐69, mean monthly attack rate was significantly lower with lanadelumab (0.41‐0.76) vs placebo (2.04), including attacks requiring acute treatment (0.33‐0.61 vs 1.66) and moderate/severe attacks (0.31‐0.48 vs 1.33, all P ≤ .001). More patients receiving lanadelumab vs placebo were attack free (37.9%‐48.1% vs 7.3%) and responders (85.7%‐100% vs 26.8%). During steady state, the efficacy of lanadelumab vs placebo was similar or improved vs days 0‐69. Intrapatient differences were significant with lanadelumab 300 mg q4wks for select outcomes. Lanadelumab efficacy was durable—HAE attack rate was consistently lower vs placebo, from the first 2 weeks of treatment through study end. Treatment emergent adverse events were comparable during days 0‐69 and 70‐182.

Conclusion

Protection with lanadelumab started from the first dose and continued throughout the entire study period.

Toll-like-receptor-3 function is critical for aortic valve stenosis development in mice

Background

Aortic valve stenosis (AS) is the most common valve diseases in the western world. After having been considered a passive degenerative process, which develops as an inevitable consequence of age-related valvular degeneration, basic research of the last two decades has led to a paradigm shift. It is now believed that AS pathophysiology is driven by distinct molecular and cellular mechanisms which include inflammatory pathways. In recent years, Toll-like-receptor-3 (TLR3) has emerged as a major regulator of vascular inflammation. TLR3 is a lysosomal pattern recognition receptor that recognizes single and double stranded RNA. Its activation leads to expression of pro-inflammatory cytokines via NFkb activation. The role of TLR3 in the development of AS has never been investigated.

Methods

Severe AS was induced in Wildtype-, ApoE- and TLR3/ApoE−/− mice. For this, a coronary springwire was used to induce an endothelial injury under echocardiographic guidance. Stenosis development was confirmed via ultrasound examinations. To inhibit TLR-3 activation, TLR3/RNA- Complex inhibitor C4a was injected every 48h after wire injury in WT mice. Valves were explanted and stained with hematoxylin/eosin (valve thickening) or anti-68 (macrophage infiltration). Valves from patients who received aortic valve replacement due to AS or aortic regurgitation (AR) were collected and mRNA levels of TLR3 and MyD88 were measured with use of quantitative-PCR.

Results

To evaluate weather TLR3 effects AS development in mice, we subjected TLR3/ApoE double- and ApoE knockout mice to our model of wire-induced AS. Surprisingly, TLR3 deficient mice failed to develop AS after wire injury. Peak velocity measurements showed no increase and histological analysis showed lower aortic valve area and macrophage infiltration compared to control mice. In order to pharmacological inhibit TLR3, WT mice were treated with C4a after wire injury. Compared to PBS control, C4a mice also did not develop AS upon wire injury. Trans-aortic valve peak velocity levels were significantly lower in C4a mice. Histological analysis underlined these results and showed thinner aortic valves and decreased macrophage infiltration in C4a mice comparted to control animals. To confirm our hypothesis, the expression of TLR3 and its downstream effector MyD88 were measured in human aortic valve specimens. qPCR analysis revealed decreased TLR3 and MyD88 expression in patients with AS compared to patients with AR.

Conclusion

In the presented study, we present first data that theTLR3 has a crucial role in the development of AS in mice. The exact downstream effects after TLR3 activation in AS need to be further investigated.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)

Parameters predicting COVID-19-induced myocardial injury and mortality

Clinical manifestations of COVID-19 affect many organs, including the heart. Cardiovascular disease is a dominant comorbidity and prognostic factors predicting risk for critical courses are highly needed. Moreover, immunomechanisms underlying COVID-induced myocardial damage are poorly understood.

OBJECTIVE

To elucidate prognostic markers to identify patients at risk.

RESULTS

Only patients with pericardial effusion (PE) developed a severe disease course, and those who died could be identified by a high CD8/Treg/monocyte ratio. Ten out of 19 COVID-19 patients presented with PE, 7 (78%) of these had elevated APACHE-II mortality risk-score, requiring mechanical ventilation. At admission, PE patients showed signs of systemic and cardiac inflammation in NMR and impaired cardiac function as detected by transthoracic echocardiography (TTE), whereas parameters of myocardial injury e.g. high sensitive troponin-t (hs-TnT) were not yet increased. During the course of disease, hs-TnT rose in 8 of the PE-patients above 16 ng/l, 7 had to undergo ventilatory therapy and 4 of them died. FACS at admission showed in PE patients elevated frequencies of CD3⁺CD8⁺ T cells among all CD3+ T-cells, and lower frequencies of Tregs and CD14⁺HLA^-DR⁺-monocytes. A high CD8/Treg/monocyte ratio predicted a severe disease course in PE patients, and was associated with high serum levels of antiviral cytokines. By contrast, patients without PE and PE patients with a low CD8/Treg/monocyte ratio neither had to be intubated, nor died.

CONCLUSIONS

PE predicts cardiac injury in COVID-19 patients. Therefore, TTE should be performed at admission. Immunological parameters for dysfunctional antiviral immunity, such as the CD8/Treg/monocyte ratio used here, supports risk assessment by predicting poor prognosis.

P4715Association of heart failure duration with clinical prognosis after transcatheter mitral valve repair

Background/Introduction

Transcatheter mitral valve repair (TMVR) in patients with heart failure (HF) and severe mitral regurgitation (MR) entails better clinical and symptomatic status. While emerging evidence indicate that HF duration is linked to adverse outcomes in patients with HF, it is not known whether the HF duration before TMVR has an effect on adverse outcomes.

Purpose

We aimed to assess the association between duration of HF before TMVR and clinical prognosis after the procedure.

Methods

We retrospectively enrolled a total of 345 patients who underwent TMVR procedure with MitraClip or Cardioband system for the treatment of symptomatic MR after guideline recommended therapy. The patients were divided into 2 groups according to the duration of HF (>18 months:, n=161, ≤18 months: shorter HF group, n=184). Cox proportional hazards analysis was performed to assess the association between duration and two-year composite endpoint (all-cause mortality, unexpected hospitalization due to HF, and repeat mitral valve therapy).

Results

Patients with longer duration of HF were more likely to be male, had greater incidence of coronary artery disease (77.0% vs. 51.6%, p<0.001), had received more frequently implantable cardioverter defibrillator or cardiac resynchronization therapy (41.0% vs. 10.3%, p<0.001), and had more decreased left ventricular ejection fraction (41.1±14.5% vs. 49.3±16.0%, p<0.001) compared to patients with shorter duration of HF. Two-year event-free survival rate was significantly lower in patients with longer duration of HF (66.3% vs. 83.8%, Log-rank p=0.01) compared to whose with shorter duration of HF. Similar trends were observed for all-cause mortality (84.8% vs. 95.9%, p=0.06) and repeat mitral valve therapy (93.4% vs. 100%, p=0.02). In the Cox proportional hazard analysis, longer duration of HF was independently associated with increased risk of adverse outcomes (Hazard ratio, 2.26; 95% confidence interval, 1.11–4.62; p=0.02) compared with shorter duration of HF.

Conclusion

Patients with the longer duration of HF before TMVR is independently associated with increased risk of adverse outcomes after the procedure. It is, however, accompanied by higher prevalence of cardiac co-morbidities in these patients. Our findings suggest that a longer duration of HF is a risk indicator and should be considered into in future clinical trials of TMVR.

P5987Novel model of intensity graded murine wire-induced aortic valve stenosis mimics distinct stages of human aortic valve pathology

Background

Aortic valve stenosis (AS) is the most common valve disease requiring therapeutic intervention. Even though the incidence of AS has been continuously rising and AS is associated with significant morbidity and mortality, to date, no medical treatments have been identified that can modify disease progression. In fact, only invasive interventional or surgical replacement of severely diseased valves is recommended. This unmet medical need is likely attributed to the lack of a clear understanding of the molecular mechanism driving disease development. To investigate the pathophysiology leading to AS, reliable and reproducible animal models that mimic human pathophysiology are needed.

Hypothesis

Induction of a graded wire-induced aortic valve stenosis model in mice is feasible to reflect and study pathophysiological mechanisms underlying the progression of aortic valve stenosis.

Methods

We have tested and expanded the protocols of a novel wire-injury induced aortic valve stenosis mouse model. A spring coronary guide wire or a bare metal wire was used to apply shear stress to the aortic valve cusps with increasing intensity with ultrasound-guided monitoring in male 10 to 12-week-old C57Bl/6j mice. These protocols allowed the induction of distinct models with soft, moderate and intense wire injury. Functional analysis including maximum flow velocity (Vmax), ejection fraction, fractional shortening, left ventricular volumes, diameters and wall thickness were assessed by echocardiography before, one and four weeks after induction of aortic valve stenosis. Immunohistological analysis were performed after eight weeks (hematoxylin and eosin, von-Kossa staining, anti-CD68-staining).

Results

Upon moderate or severe injury, AS developed with a significant increase in aortic valve peak blood flow velocity. While moderate injury promoted solitary AS, severe-injury induced mixed aortic valve disease with concomitant mild to moderate aortic regurgitation. Only 5% of the mice who received a moderate injury displayed a mild aortic regurgitation. In the group of mice with intense injury 50% of the mice had a mild and 18,75% had a moderate aortic insufficiency. The changes in aortic valve function were reflected by dilation and hypertrophy of the left ventricle, as well as a decreased left ventricular ejection fraction after intense injury, while moderate injury did not show significant dilation of the left ventricle. Histological analysis revealed the three classic hallmarks of human disease with aortic valve thickening, increased macrophage infiltration and calcification eight weeks after injury.

Conclusion

Hereby, we demonstrate that the induction of a graded wire induced aortic valve stenosis model in mice mimicking relevant pathophysiological mechanisms is feasible to study disease progression. We extended existing protocols to induce moderate stenosis allowing to solely study aortic valve stenosis without relevant aortic valve regurgitation.

Acknowledgement/Funding

S.N. was funded by Else-Kröner-Fresenius-Foundation of the Medical Faculty of the University of Bonn

P4145Endothelial NLRP3-Inflammasome impairs vascular function via microparticles

Background

In recent years inflammation has emerged to the centre of attention of cardiovascular research. One of its key figures is the NLRP3-inflammasome a multimeric protein complex that stimulates inflammatory responses in atherogenesis through proinflammatory cytokines like caspases IL-1β and -18. It is activated by danger signals such as cholesterol crystals, oxidized LDL, ATP or uric acids. Microparticles (MP) are extracellular vesicles that are released by activated or apoptotic cells. They are known as a vector for the intercellular transfer of biological information. The body of evidence indicates that endothelial microparticles contribute to the development and complications in atherosclerosis. With this study we sought to elucidate the effects microparticles, that are discharged by inflammasome activated endothelial cells, exert on arterial vascular cells.

Methods and results

RTPCR experiments showed that activation of human coronary artery endothelial cells (HCAEC) with LPS and Nigericin leads to NLRP3-inflammasome-specific upregulation of NLRP3 and IL1β. Analysis of the supernatant of aforementioned cells via westernblot revealed release of cleaved caspase-1 while donorcells undergo pyroptosis. FACS and electronmicroscopy experiments revealed time dependent release of endothelial microparticles (EMP) by inflammasome activated HCAEC, while western blot demonstrated that EMP enclose active caspase-1. Fluorescence microscopic imaging illustrated time dependent incorporation of EMP by HCAEC. Stimulation of HCAEC with EMP revealed detrimental biological effects on recipient cells as viability assay and scratch assay showed decreased viability and proliferation/ migration, cytotoxity assay showed increased cytotoxity and RT-PCR experiments showed increased expression of NALP3, IL-1b, VCAM and ICAM. The fact that treatment of recipient cells with the NLRP3-Inhibitor isoliquiritigenin (ILG), heat-inactivation of EMP and rupturing the EMP-membrane by freezing is able to diminish harmful effects EMP exert on recipient cells shown by viability assay, scratch assay and microscopic imaging underlines detrimental effects being exerted by EMP-encapsuled inflamasome-components.

Conclusion

Our findings verify that MP released from inflammasome-activated endothelial cells are incorporated by vascular cells which in turn sustain a reduction of cell viability, migration and proliferation. EMP effectuate activation of the NLRP3-inflammasme in their target cells. The cytotoxic effects of EMP are suppressed by inhibitors of the NLRP3-inflammasome and affection of EMP-membrane. Our results emphasize the immunological role of endothelial cells and indicate that inflammasome activation is transferable through microparticle-associated communication. This in turn facilitates cell death and possibly initiates a vicious cycle of inflammation suggesting a role in the advancement of atherosclerosis.

Acknowledgement/Funding

Else Kröner Scholarship

P5993Comprehensive characterization of experimental aortic valve stenosis by multiparametric MRI

Background

Recently, we established an experimental model of moderate aortic valve stenosis (AS) aiming to mimic human disease progression closely. Functional and structural MRI of a mouse model in experimental aortic valve stenosis has not been accomplished so far.

Purpose

Here, we aimed at developing comprehensive MRI approach for simultaneous assessment of changes in valvular, left ventricular and aortic morphology and function.

Methods

Male 12-week-old wildtype mice (C57Bl/6) were subjected to wire injury of the aortic valve to induce aortic valve stenosis. High resolution MRI at 9.4T was used to monitor subsequent functional and structural changes in the aortic valve, the ascending aorta, the left ventricle and aortic flow patterns.

Results

MRI permits accurate planimetry of the orifice and the thickness of the aortic valve, allows a reliable three-dimensional mapping of transvalvular aortic flow, simultaneously depicts aortic regurgitation in 3D fashion and permits assessment of left ventricular changes due to AS. In our model we observed a reduced valve orifice and an increase in valve thickness. Homogenous flow pattern under control converted to heterogenous and turbulent flow with progression of AS associated with increased aortic strain, aortic wall and left ventricular wall thickness.

Conclusions

In a murine model of aortic valve stenosis MRI is capable to reliably display a three-dimensional transvalvular aortic flow profile with concomitant quantification of structural and functional changes in aortic valve, left ventricle, and ascending aorta. This comprehensive functional imaging at high resolution and distinct reproducibility offers for the first time serial assessment of disease progression in an experimental model of aortic valve stenosis.

P973Intravascular lithotripsy for lesion preparation in calcified coronary lesions: a prospective, observational, two-center registry

Background

Intravascular coronary lithotripsy (IVL) is a novel alternative treatment for heavily calcified lesions. This study sought to determine the strategy success and safety of IVL on calcified lesions in an all-comers cohort of patients.

Methods

Patients with moderate and severely calcified coronary lesions were screened in two centers in Spain and Germany starting April 2018. Until February 2019, 61 patients with 67 lesions were eligible for IVL. Patients were assigned to the following groups: A) Primary IVL therapy for patients with circumferential calcified de-novo coronary lesions (n=32), B) Secondary IVL therapy for patients with moderate or severe calcified coronary lesions in which conventional non-compliant balloon dilatation failed (n=18) and C) Tertiary IVL therapy in patients with in-stent stenosis due to stent underexpansion after previous stenting (n=17). Primary endpoint was strategy success and safety outcome. Strategy success was defined as successful stent delivery and expansion with attainment of <20% in-stent residual stenosis of the target lesion. Safety outcome were procedural complication, defined as coronary dissection, slow or no-reflow phenomenon, new coronary thrombus formation during PCI, abrupt vessel closure and device failure (inability to place the balloon, malfunction, or burst) and in hospital MACE.

Results

61 patients with 67 calcified lesions were treated with IVL. Mean diameter of calcified stenosis on quantitative coronary angiography was 72.02±13.8% at baseline and decreased to 17.7±15.84% (p-value: <0.01) after IVL with an acute gain of 1.9±0.63 mm. Mean minimal lumen diameter was 1.0±0.5 mm at baseline and increased after IVL to 2.9±0.6 mm. The overall average of applied pulses was 63±22. The primary endpoint of strategy success was reached overall in 85.2% of patients. 4 type b dissections (3 in group A, 1 in group B) were observed without further sequelae. There were no in-hospital MACE. In one patient (1.6%) non-ischemia driven target lesion failure was observed in routine follow up coronary angiography and was in need for revascularization. According to the subgroups, strategy success in primary IVL treatment (group A) and secondary IVL treatment (group B) was reached in 81.3% and 83.3% of cases, respectively. In tertiary IVL therapy (group C), the primary study endpoint was reached in 64.7% of cases. Device delivery and IVL treatment of target lesion could be performed in all lesions without vessel complications. 7 IVL balloons ruptured during treatment without any sequelae. Rupture was observed in most cases after repositioning of the balloon within the calcified lesion.

Conclusions

IVL provides a valid strategy for lesion preparation in severely calcified coronary lesions, with high success rate, and low procedural complication and MACE rates. Longitudinal studies will confirm if these favourable initial results of IVL-supported PCI are followed by good long-term results.

P5988Non-classical Ly6C-low monocytes contribute to aortic valve stenosis development in mice

Introduction

Aortic valve stenosis (AS) is one of the most common valvular diseases in the western world. Once patients with AS develop symptoms mortality increases up to 50% over two years. For many years AS was believed to be a passive degenerative process. Recent findings suggest a more complex pathomechanism with a strict molecular and cellular regulation involving local inflammation and invasion of immune cells. Specifically, pro-inflammatory macrophages have been shown to play an important role in disease progression. On the other hand, monocyte counts in the peripheral blood of patients with severe AS are significantly decreased and there is an inverse correlation between valve orifice area and circulating monocyte count. In order to elucidate the exact function of pro-inflammatory classical (Ly6C-high) and non-classical (Ly6C-low) monocytes in disease initiation processes, we conducted a series of experiments in a model of murine AS.

Methods

In this study 10–12 weeks old male C57BL6/J or CX3CR1-deficient mice were investigated. For AS induction, a coronary springwire was introduced into the left ventricle, pushed and rotated over the aortic valve under echocardiographic guidance. In sham operated mice the wire was only inserted into the left carotid artery without manipulation of the aortic valve. Development of AS was confirmed via weekly ultrasound examinations. Immune cells in the aortic valve were quantified using flow cytometry and immunofluorescence microscopy.

Results

Ultrasound analysis after two weeks confirmed the development of AS in the injured wildtype mice. Transaortic peak velocity levels were significantly increased compared to sham operated mice. Flow cytometry of explanted aortic valves showed a strong cellular immunoreaction in the stenotic valves. The amount of anti-inflammatory Ly6C-low monocytes was significantly increased compared to sham-mice, whereas the number of pro-inflammatory Ly6C-high monocytes remained stable. Interestingly CD-4 positive T-cells were augmented in stenotic aortic valves. Immunofluorescence confirmed Ly6C-low monocytes infiltration in the valve, in close proximity to the endothelial cells on the ventricular and the aortic side. The expression of recruitment and adhesion markers CD11b and CX3CR1 were significantly increased on the surface of the Ly6C-low monocytes of AS mice. To investigate the role of Ly6C-low monocytes in AS development, CX3CR1 deficient mice, which are not able to recruit non-classical monocytes via CX3CR1, were subjected to aortic valve wire injury. After two weeks, peak velocity levels in CX3CR1−/− mice remained nearly unchanged and were significantly decreased compared to wildtype mice.

Conclusion

Our data suggest that non-classical Ly6Clow monocytes play a crucial role in AS development in mice. Therefore, they may be targets for future therapeutic interventions.

Acknowledgement/Funding

S.T.N. was funded by Else-Kröner-Fresenius-Foundation of the Medical Faculty of the University of Bonn

Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 ¹/₂ years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

[Is routine histopathologic examination of middle ear cholesteatoma necessary?]

BACKGROUND

In the course of restoration of the middle ear, routine histological examinations are initiated in many cases, although a middle ear cholesteatoma can be clinically diagnosed in a normal case.

AIM OF THE STUDY

To determine the correlation between the surgeons' diagnosis and that of the pathologist and comparison with literature data. To check the rate of unexpected diagnoses. Analysis of the costs and survey of German ENT clinics with regard to handling of the histological examination in suspected cholesteatoma.

MATERIALS AND METHODS

Retrospective evaluation of cholesteatoma cases of the ENT Department of the University Medical Center of Mainz from 2010-2015. Germany-wide postal survey of ENT clinics.

RESULTS

In all, 449 operations for the rehabilitation of a middle ear cholesteatoma, of which there were 312 (69.5%) first diagnoses and 137 (30.5%) recurrences. A histological examination was conducted in 78.6%. For first diagnoses, the sensitivity of the clinical assessment was 97.9%, specificity 10%, positive predictive value 96.3%, and negative predictive value 16.7%. Recurrences showed values of 100%, 40%, 97.1% and 100%. Unexpected malignant findings did not occur. This routine histological examination was performed by 58.6% of German ENT hospitals. A total of 80% of those questioned this to be useful. A histological examination cost an average of 14.06 €.

CONCLUSION

Intraoperatively, there is a high degree of accuracy in diagnosing cholesteatoma. The cost factor of the histological examination is low and should not be the basis for the decision. The ear microscopy and the experience of the ear surgeon should be decisive for the decision for histological examination.

Assessing the Safety and Efficacy of Regional Anesthesia for Lower Extremity Microvascular Reconstruction: Enhancing Recovery

BACKGROUND

 Perioperative pain, increased sympathetic tone, and peripheral vasospasm may be safely managed with regional nerve blockade during microvascular reconstruction in the lower extremity. Limited reports exist in this setting; therefore, we evaluated our use of peripheral nerve catheters (PNCs) during microvascular limb salvage to determine safety and efficacy for both patient and flap.

METHODS

 A single-institution, retrospective review of a prospectively maintained database on all patients with lower extremity free tissue transfers between 2012 and 2017 was completed. Patients were matched into groups based on PNC utilization. The use of intravenous narcotics including patient-controlled analgesia (PCA), oral narcotics, antiemetics, length of stay (LOS), associated pain scores, flap-related performance, and patient morbidity was recorded.

RESULTS

 Of 48 patients who underwent lower extremity free tissue transfer, 35 satisfied criteria for comparison. Of these, PNC was utilized in 83%. The mean pain score in the immediate postoperative period was 3.84 ± 2.47 (10-point Likert scale). PCA and narcotic use were decreased in the PNC group, and no adverse effects of the catheter were identified. Microsurgical outcomes were not adversely affected in comparison.

CONCLUSION

 PNC utilization for lower extremity free flap transfer significantly reduced concurrent narcotic use and attained a shorter LOS. The technique provided for safe analgesia during lower extremity free flap reconstructions satisfying the microsurgeon and the anesthesiologist.

Clinical prediction rule to determine the need for repeat ERCP after endoscopic treatment of postsurgical bile leaks

BACKGROUND AND AIMS

In patients who have undergone ERCP with biliary stenting for postsurgical bile leaks, the optimal method (ERCP or gastroscopy) and timing of stent removal is controversial. We developed a clinical prediction rule to identify cases in which a repeat ERCP is unnecessary.

METHODS

Population-based study of all patients who underwent ERCP for management of surgically induced bile leaks between 2000 and 2012. Multivariate and binary recursive partitioning analyses were performed to generate a rule predicting the absence of biliary pathology on repeat endoscopic evaluation.

RESULTS

A total of 259 patients were included. On multivariate analysis, postsurgical normal alkaline phosphatase (ALP; OR, 2.26; 95% CI, 1.03-4.99), time from surgery to first ERCP < 8 days (OR, 2.47; 95% CI, 1.15-5.31), and minor leak with no other pathology on initial ERCP (OR, 6.74; 95% CI, 1.75-25.89) were independently associated with the absence of persistent bile leak and other pathology on repeat ERCP. The derived rule included laparoscopic cholecystectomy, normal postsurgical ALP, minor leak with no other pathology on initial ERCP, and an interval from initial to repeat ERCP between 4 and 8 weeks. When all 4 criteria were met, the rule had a sensitivity of 94% (95% CI, 83%-99%) and a negative predictive value of 93% (95% CI, 81%-99%). Optimism-adjusted sensitivity and negative predictive value were 88% (95% CI, 76%-96%) and 86% (95% CI, 73%-96%), respectively.

CONCLUSIONS

This clinical decision rule identifies patients who can have their biliary stents removed via gastroscopy, which may improve patient safety and healthcare utilization.

Search for Cosmic-Ray Electron and Positron Anisotropies with Seven Years of Fermi Large Area Telescope Data

The Large Area Telescope on board the Fermi Gamma-ray Space Telescope has collected the largest ever sample of high-energy cosmic-ray electron and positron events since the beginning of its operation. Potential anisotropies in the arrival directions of cosmic-ray electrons or positrons could be a signature of the presence of nearby sources. We use almost seven years of data with energies above 42 GeV processed with the Pass 8 reconstruction. The present data sample can probe dipole anisotropies down to a level of 10^{-3}. We take into account systematic effects that could mimic true anisotropies at this level. We present a detailed study of the event selection optimization of the cosmic-ray electrons and positrons to be used for anisotropy searches. Since no significant anisotropies have been detected on any angular scale, we present upper limits on the dipole anisotropy. The present constraints are among the strongest to date probing the presence of nearby young and middle-aged sources.

Pen-type laser fluorescence device versus bitewing radiographs for caries detection on approximal surfaces

Background

The accurate detection of approximal caries is generally difficult. The aim of this study was to assess the ability of the pen-type laser fluorescence device (LF pen) to detect approximal carious lesions in comparison to bitewing radiographs (BW).

Methods

Three hundred forty-one tooth surfaces were diagnosed in 20 patients with an average age of 26.70 (±2.82) years. Each test tooth was sequentially assessed by a single calibrated examiner using visual inspection, BW, and the LF pen. Radiographs were used as the gold standard to calculate an appropriate cut-off.

Results

Sensitivity, specificity and accuracy values for cut-off limits of 15, measured by the LF pen were compared using the chi² test (McNemar test). For approximal caries at D3 level, the highest values of specificity and sensitivity were observed for the LF pen at a cut-off value of 15 (96.8 and 83.0 %) and for visual inspection (99.3 and 4.3 %).

Conclusion

Within the limitations of this study, dentin caries on approximal surfaces could be detected equally well by the LF pen as by the bitewing radiographs. Therefore, the LF pen can be recommended as an alternative to radiographs for the detection of approximal caries in a regular dental practice setting.

Trial registration

DRKS00004817 on DRKS on 12^th March 2013.

Search for Spectral Irregularities due to Photon-Axionlike-Particle Oscillations with the Fermi Large Area Telescope

We report on the search for spectral irregularities induced by oscillations between photons and axionlike-particles (ALPs) in the γ-ray spectrum of NGC 1275, the central galaxy of the Perseus cluster. Using 6 years of Fermi Large Area Telescope data, we find no evidence for ALPs and exclude couplings above 5×10^{-12}  GeV^{-1} for ALP masses 0.5≲m_{a}≲5  neV at 95% confidence. The limits are competitive with the sensitivity of planned laboratory experiments, and, together with other bounds, strongly constrain the possibility that ALPs can reduce the γ-ray opacity of the Universe.