Chromosomal, epigenetic and microRNA-mediated inactivation of LRP1B, a modulator of the extracellular environment of thyroid cancer cells

The low-density lipoprotein receptor-related protein (LRP1B), encoding an endocytic LDL-family receptor, is among the 10 most significantly deleted genes across 3312 human cancer specimens. However, currently the apparently crucial role of this lipoprotein receptor in carcinogenesis is not clear. Here we show that LRP1B inactivation (by chromosomal, epigenetic and microRNA (miR)-mediated mechanisms) results in changes to the tumor environment that confer cancer cells an increased growth and invasive capacity. LRP1B displays frequent DNA copy number loss and CpG island methylation, resulting in mRNA underexpression. By using CpG island reporters methylated in vitro, we found that DNA methylation disrupts a functional binding site for the histone-acetyltransferase p300 located at intron 1. We identified and validated an miR targeting LRP1B (miR-548a-5p), which is overexpressed in cancer cell lines as a result of 8q22 DNA gains. Restoration of LRP1B impaired in vitro and in vivo tumor growth, inhibited cell invasion and led to a reduction of matrix metalloproteinase 2 in the extracellular medium. We emphasized the role of an endocytic receptor acting as a tumor suppressor by modulating the extracellular environment composition in a way that constrains the invasive behavior of the cancer cells.

Immunohistochemical demonstration of an organized cytoarchitecture of the radial glia in the CNS of the embryonic mouse

Immunocytochemical staining using antivimentin and anti-glial fibrillary acidic protein sera on nervous tissue sections shows a well-organized pattern of radial glial fibers as early as 15 days in the embryonic mouse. The glial fibers, isolated or in fascicles, form parallel palisades in rectilinear and longitudinal alignment in the spinal cord, medulla and pons. Certain areas show a double system of palisades, perpendicular to each other. The architecture is more complex at the cerebral level. There is a close relationship between the tracks followed by the axon bundles and the pattern of the glial palisades. The fibers have a helical structure, often with a very regular periodicity. The functional implications of the location and structure of the radial fibers during ontogenesis are discussed.

Peroxiredoxin 2, glutathione peroxidase, and catalase in the cytosol and membrane of erythrocytes under H2O2-induced oxidative stress

Erythrocytes are continuously exposed to risk of oxidative injury due to oxidant oxygen species. To prevent damage, they have antioxidant agents namely, catalase (Cat), glutathione peroxidase (GPx), and peroxiredoxin 2 (Prx2). Our aim was to contribute to a better understanding of the interplay between Prx2, Cat, and GPx under H2O2-induced oxidative stress, by studying their changes in the red blood cell cytosol and membrane, in different conditions. These three enzymes were quantified by immunoblotting. Malondialdehyde, that is, lipoperoxidation (LPO) in the erythrocyte membrane, and membrane-bound hemoglobin (MBH) were evaluated, as markers of oxidative stress. We also studied the erythrocyte membrane protein profile, to estimate how oxidative stress affects the membrane protein structure. We showed that under increasing H2O2 concentrations, inhibition of the three enzymes with or without metHb formation lead to the binding of Prx2 and GPx (but not Cat) to the erythrocyte membrane. Prx2 was detected mainly in its oxidized form and the linkage of metHb to the membrane seems to compete with the binding of Prx2. Catalase played a major role in protecting erythrocytes from high exogenous flux of H2O2, since whenever Cat was active there were no significant changes in any of the studied parameters. When only Cat was inhibited, Prx2 and GPx were unable to prevent H2O2-induced oxidative stress resulting in increasing MBH and membrane LPO. Additionally, the inhibition of one or more of these enzymes induced changes in the anchor/linker proteins of the junctional complexes of the membrane cytoskeleton-lipid bilayer, which might lead to membrane destabilization.

Immunohistochemical localization of the myelin basic protein and of the glial fibrillary acidic protein: comparative study in normal, quaking and jimpy mice

The topographical distribution of myelin basic protein (MBP) and of glial fibrillary acidic protein (GFA) have been compared in the CNS of 18-day-old normal, quaking, and jimpy mice using indirect immunofluorescence. Comparison was made in brain and spinal cord sections. MBP was strongly decreased in quaking and jimpy mice in all parts of the CNS. A pronounced gliosis was observed in jimpy mice with occurrence of numerous hypertrophied astrocytes. To a lesser extent, an astrocytic reaction was also observed in quaking CNS.

Trends, seasonality and forecasts of pulmonary tuberculosis in Portugal

SETTING

Tuberculosis (TB) is a global public health concern. Surveillance programmes present invaluable epidemiological information regarding its temporal evolution, particularly for pulmonary tuberculosis (PTB), the most common form of TB and the one that presents the greatest challenge in public health.

OBJECTIVES

To characterise, model and predict monthly incidence rates for PTB in Portugal disaggregated by high/low-incidence areas, sex and age groups.

DESIGN

PTB monthly incidence rates were estimated based on PTB cases diagnosed in 2000-2010, disaggregated by population and geographic characteristics. Seasonal-trend LOESS (STL) decomposition was employed to model trend and seasonality. Seasonal autoregressive integrated moving average (SARIMA) models were fit to characterise series behaviour and forecast PTB monthly incidence rates.

RESULTS

Overall, the time series showed a downward trend in and seasonality of PTB diagnosis, with a peak in March and a trough in December. The mean seasonal amplitude was consistently higher in high-incidence areas, in males and in adults aged 25-54 years. SARIMA models were found to adequately fit and forecast the time series, thus predicting trend and seasonal persistence.

CONCLUSIONS

STL and SARIMA findings concurred and were accurate. Endemic PTB seems to be slowly declining and case diagnosis is likely seasonal, which can be expected to persist if past conditions continue.

Endoluminal smooth muscle cell seeding limits intimal hyperplasia

PURPOSE

Intimal hyperplasia is one of the main responses of the vascular wall to injury. In the current study, we tested the hypothesis that endoluminal seeding of host syngeneic vascular cells could limit intimal hyperplasia induced by either mechanical deendothelialization or chronic allograft rejection in rat aorta.

METHODS

An experimental model of in situ seeding of syngeneic endothelial cells, smooth muscle cells (SMCs), and fibroblasts (FIBs) was used in mechanically deendothelialized and allografted aortas. In a preliminary study, the ability of the three cell types (n = 5 per group) to seed on the deendothelialized luminal surface of the aortic wall was evaluated after 2 days, with the use of fluorescent PKH as marker. In the first model, the abdominal aorta of Lewis rats was deendothelialized (n = 6) or deendothelialized and seeded with either SMCs (n = 6) or FIBs (n = 6) before flow was restored. In the allograft model, aortas were harvested from dark agouti rats and orthotopically grafted in Lewis receivers, directly (n = 6) or after deendothelialization. Deendothelialization was performed alone (n = 6) or associated with the seeding of similar host (Lewis) syngeneic SMCs (n = 6) or FIBs (n = 6). Results were evaluated at 2 months with histologic and morphometric methods.

RESULTS

SMCs and FIBs were able to adhere in situ to the deendothelialized aortic wall, whereas endothelial cells were not. In mechanically deendothelialized aortas, the seeding of syngeneic SMCs led to a significant reduction in intimal thickness compared with deendothelialized aortas or FIB-seeded aortas (26.9 +/- 1.7 microm vs 55.5 +/- 1.7 and 56.7 +/- 1.7 microm, respectively), and a lower nuclear content (382.2 +/- 35.7 microm(2) vs 779.6 +/- 65.9 and 529.6 +/- 24.3 microm(2), respectively) of neointima. After SMC seeding, intimal hyperplasia was richer in elastin, whereas after FIB seeding it was richer in collagen. In allografts, the seeding of syngeneic SMC led to a significant reduction in intimal thickness compared with control aortas, deendothelialized aortas, or FIB-seeded aortas (31.6 +/- 1.1 microm vs 88.55 +/- 2.8, 74.6 +/- 2.9, and 85.7 +/- 2.6 microm, respectively), and a reduced nuclear content of the neointima (444.9 +/- 23.4 microm(2) vs 1529.1 +/- 116, 972.3 +/- 50, and 645.2 +/- 32.4 microm(2), respectively). Differences observed in the extracellular matrix composition were equivalent to those observed in the mechanically deendothelialized model.

CONCLUSIONS

Our results suggest that endoluminal seeding of syngeneic SMCs can be effective in reducing intimal hyperplasia both in a deendothelialization model and in arterial allografts. SMC and FIB endoluminal seeding led to a significatively different accumulation of extracellular matrix in the intima.

Discovering the infectome of human endothelial cells challenged with Aspergillus fumigatus applying a mass spectrometry label-free approach

Blood vessel invasion is a key feature of invasive aspergillosis. This angioinvasion process contributes to tissue thrombosis, which can impair the access of leukocytes and antifungal drugs to the site of infection. It has been demonstrated that human umbilical vein endothelial cells (HUVECs) are activated and assume a prothrombotic phenotype following contact with Aspergillus fumigatus hyphae or germlings, a process that is independent of fungus viability. However, the molecular mechanisms by which this pathogen can activate endothelial cells, together with the endothelial pathways that are involved in this process, remain unknown. Using a label-free approach by High Definition Mass Spectrometry (HDMS(E)), differentially expressed proteins were identified during HUVEC-A. fumigatus interaction. Among these, 89 proteins were determined to be up- or down-regulated, and another 409 proteins were exclusive to one experimental condition: the HUVEC control or HUVEC:AF interaction. The in silico predictions provided a general view of which biological processes and/or pathways were regulated during HUVEC:AF interaction, and they mainly included cell signaling, immune response and hemostasis pathways. This work describes the first global proteomic analysis of HUVECs following interaction with A. fumigatus germlings, the fungus morphotype that represents the first step of invasion and dissemination within the host.

BIOLOGICAL SIGNIFICANCE

A. fumigatus causes the main opportunistic invasive fungal infection related to neutropenic hematologic patients. One of the key steps during the establishment of invasive aspergillosis is angioinvasion but the mechanism associated with the interaction of A. fumigatus with the vascular endothelium remains unknown. The identification of up- and down-regulated proteins expressed by human endothelial cells in response to the fungus infection can contribute to reveal the mechanism of endothelial response and, to understand the physiopathology of this high mortality disease. This article is part of a Special Issue entitled: Trends in Microbial Proteomics.

Early expression of carbonic anhydrase II (CAII) in transitory glial cells of the developing murine nervous system

Using immunocytochemical methods carbonic anhydrase II (CAII) has been detected in the embryonic mouse central nervous system as early as in stage E16. In the spinal cord and the brain stem, the enzyme first appeared in transitory cells probably derived from the radial glia. In the cerebrum such transitory cells were never stained with anti-CAII sera. The bodies of CAII-positive cells were never visualized in the ventricular layer. The controversial cellular specificity of CAII made it impossible to specify the glial lineage to which these transitory CAII-positive cells are committed.

Expression of carbonic anhydrase II gene in early brain cells as revealed by in situ hybridization and immunohistochemistry

A mouse carbonic anhydrase (CA II) complementary(c) DNA probe was used for in situ hybridization on mouse brain cultured cells in order to follow CA II gene expression during brain development. An improved method was established using biotinated probes that resulted in a high sensitivity and an absence of background; this method could be combined with immunohistochemistry. Hypothalamic cells of embryonic day (ED) 12-14 mice were cultured for various periods. Chronologic appearance of CA II messenger(m)RNA and protein was studied. The CA II gene transcripts are detectable as early as ED 12-13, although the protein they encode is not detectable until ED 17-18. Gene expression is restricted to 0.1% of the total population. Northern blot analysis confirmed the presence of CA II transcripts in embryonic hypothalamus. At postnatal stage, the majority of glial cells express both the CA II mRNA and the protein. Our results favour the early appearance of a glial lineage in a precise area of the developing CNS. The precocity of CA II gene transcription makes in situ hybridization an invaluable approach in defining the onset of nerve cell lineages during embryonic development.

Comparative morphology of the reproductive system of seven species of ostariophysan fishes from the upper Das Velhas River, Brazil

The success of fishes in different environments is related with the variation of reproductive strategies developed by the systematic group, which is reflected in the morphology of the reproductive system and can have ecological and evolutionary implications. This study comparatively analyzed the morphological characteristics of the male and female reproductive systems of ostariophysan fish species from the upper Das Velhas River in the São Francisco River basin, Brazil. In order to accomplish this, 393 specimens belonging to seven fish species were sampled between April 2010 and June 2015 for histological, ultrastructural, histochemical, and morphometric analyses. All the species examined have anastomosing tubular testes with unrestricted distribution of spermatogonia. Astyanax bimaculatus, A. fasciatus, A. scabripinnis, and Harttia torrenticola had their spermatozoa embedded in a glycoprotein secretion within the tubule lumen. Most species had type I spermiogenesis, whereas Rhamdia quelen had type III spermiogenesis. While all females examined had asynchronous oocyte development, there were remarkable morphological, histochemical, and morphometric differences in the ovarian follicles and enveloping layers. Hoplias malabaricus and H. torrenticola, which exhibit parental care behaviour, had a significantly larger diameter of vitellogenic oocytes and larger spermatozoa nuclei. Apareiodon ibitiensis, H. torrenticola, and A. scabripinnis, species that have rheophilic preferences, exhibited a thicker zona radiata than the other species examined. The follicular cells of R. quelen and H. torrenticola were columnar and produced a jelly coat and mucosubstances, respectively. The females of the seven fish species studied show a correlation of the reproductive strategies with the reproductive system morphology, while males retained more similar morphological characteristics between species. J. Morphol. 278:170-181, 2017. © 2016 Wiley Periodicals,Inc.

Importância do eletrorretinograma de campo total (Full field ERG) em cães da raça Cocker Spaniel Inglês portadores de catarata

Com o aumento do número de intervenções cirúrgicas para a remoção da catarata em cães, observa-se a necessidade de exames específicos que devem ser realizados antes da indicação cirúrgica. A catarata é uma das principais causas de cegueira em cães. Nos estágios mais avançados, impossibilita o exame fundoscópico e inviabiliza a observação de alterações retinianas como a atrofia progressiva da retina (APR), degeneração retiniana hereditária de acometimento bilateral que, quando diagnosticada, contra-indica a cirurgia. Com o intuito de reestabelecer a visão, o eletrorretinograma de campo total (Full field ERG) torna-se indispensável na avaliação pré-cirúrgica da remoção da catarata. Como os cães da raça Cocker Spaniel Inglês são predispostos à catarata e a degenerações retinianas, objetivamos neste estudo avaliar as respostas dos ERGs realizados nestes animais. Foram avaliados 136 eletrorretinogramas de cães da raça Cocker Spaniel Inglês (62 machos e 74 fêmeas, com idades entre 3 e 15 anos) no período de Setembro de 2004 a Maio de 2009. Todos os animais apresentavam baixa de visão e catarata durante o exame. O diagnóstico de degeneração retiniana foi baseado nos valores de amplitude pico a pico e tempo de culminação da onda-b nas 3 respostas (resposta escotópica de bastonetes, máxima resposta e resposta fotópica de cones), idade do paciente e estágio de maturação da catarata. Nos cães sem degeneração retiniana, a média da amplitude e do tempo de culminação nas três respostas obtidas foram, respectivamente: 71,55mV/65,15ms; 149,17mV/33,03ms; 31,06mV/27,90ms. Nos cães com degeneração retiniana, 38 animais apresentaram ERG extinto. Dentre os restantes que apresentavam baixas respostas, a média da amplitude e do tempo de culminação nas três respostas obtidas foram, respectivamente: 12,88mV/65,04ms; 24,16mV/36,25ms; 8,36mV/31,38ms. Foi observado que em 122 animais (89,7%) os exames eram compatíveis com diagnóstico de atrofia progressiva da retina. Frente aos resultados obtidos, conclui-se que os cães da raça Cocker Spaniel Inglês portadores de catarata devem ser submetidos ao eletrorretinograma de campo total antes da remoção cirúrgica devido à alta incidência de degeneração retiniana nesta raça.

Coronary artery calcium score to predict coronary CT angiography interpretability: an old problem revisited

Funding Acknowledgements

Type of funding sources: None.

Introduction

Clinical guidelines recommend against the use of coronary computed tomography angiography (CCTA) in patients with heavy calcification due to interpretability concerns, but no specific approach or threshold is provided. Recently, alternative methods have been proposed as more reliable predictors of CCTA interpretability than the classic coronary artery calcium score (CACS).  The purpose this study was to compare the performance of different measures of coronary calcification as predictors of CCTA interpretability.

Methods

We conducted a retrospective analysis of consecutive patients undergoing CACS and CCTA between 2018 and 2020. The key exclusion criteria were known coronary artery disease, CACS of zero, and presence of non-assessable coronary lesions for reasons other than calcification (movement/gating artifacts or vessel diameter < 2mm). CCTA studies were considered non-interpretable if the main reader considered one or more coronary lesions non-assessable due to calcification. Three different measures of coronary calcification were compared using ROC curve analysis: 1) total CACS; 2) CACS-to-lesion ratio (total CACS divided by the number of calcified plaques); and 3) calcium score of the most calcified plaque. Decision-tree analysis was performed to identify the algorithm that best predicts CCTA interpretability.

Results

A total of 432 patients (191 women, mean age 64 ± 11 years) were included. Overall, 31 patients (7.2%) had a non-interpretable CCTA due to calcification. Patients with non-interpretable CCTA had higher CACS (median 589 vs. 50 AU, p < 0.001), higher CACS-to-lesion ratio (median 43 vs. 14 AU/lesion, p < 0.001), and higher score of the most calcified plaque (median 445 vs. 43 AU, p < 0.001). Among the 3 methods, CACS showed the highest discriminative power to predict a non-interpretable CCTA (C-statistic 0.93, 95%CI 0.89-0.95, p < 0.001) - Figure.

Decision-tree analysis identified a single-variable algorithm (CACS value ≤ 515 AU) as the best discriminator of CCTA interpretability: 396 of the 409 patients (97%) with CACS ≤ 515 AU had an interpretable CCTA, whereas only 5 of the 23 patients (22%) with CACS > 515 AU had an interpretable test, yielding a total of 96% correct predictions.

Conclusions

The recently proposed and more complex measures of coronary calcification seem unable to outperform total CACS as a predictor of CCTA interpretability. A simple CACS cutoff-value around 500 AU remains the best discriminator for this purpose.

Whey protein supplementation in muscle hypertrophy

Introduction The nutritional intake in the context of a hypertrophy training can affect body composition, the increase of muscle mass and strength. Whey protein seems to promote a reduction in body fat, improve hypertrophy, and other potential health benefits. This protein is one of the highest quality proteins due to its amino acid content (especially leucine) and to the rapid digestibility. Whey protein consumption has a robust ability to stimulate muscle protein synthesis. There are 3 types of whey protein: controlled, insulated and hydrolysed.

Objectives The goal of this research is verifying the efficacy of the use of whey protein supplementation in athletes seeking muscle strength and mass gain.

Methodology *

We analysed scientific articles from 2014 to 2019, based on Pubmed and Google scholar. Keywords such as whey protein, supplement, hypertrophy, muscle mass and nutrition were used.

Results From scientific research, six articles were analysed. Thus, it is estimated the analysis of 13 men under the age of 18 years and under 30 years of age. Only men with a percentage of fat mass less than or equal to 23% were selected. Two groups were created: the control group that consumed carbohydrate supplements and the experimental group that consumed 36g/day whey protein. Both groups performed 3 sessions/week of resistance training, and the used dose of protein derived from the diet was 1.4g/Kg/day. Both groups experienced gains in strength, 1 maxi (RM) and fat-free mass (FFM). However, the experimental group had an extra 9% and 27% in 1RM and FFM respectively compared to the control group.

Conclusion In short, supplementation with whey protein contributes to the increase of muscle mass and strength in athletes whose training (frequency, volume and duration) and diet are suitable for this purpose.

A-17 Effects Of Parental Mental Health On Patient and Parent-Reported Anxiety Symptoms Following Concussion In Adolescents

Purpose: Examine the impact of parental mental health history on patient and patent-reported post-concussion symptoms of anxiety. Methods: Participants included 105 adolescents (42.9% male), 12–18 years old, including concussion patients (n = 72, 3.42 ± 1.7 days post-injury) and age-and-sex matched controls (n = 33). Patients and parents completed the Screen for Child Anxiety Disorders, Parent and Child versions (SCARED-P, SCARED-C) and medical histories. T-tests were used to compare control/concussed responses on the SCARED. Logistic regression (LR) was used to evaluate group predictors, as well as high/low (i.e., >21 PCSS total score) concussion symptom groups at 30 days post-injury. Results: Results indicated that concussed SCARED-C (controls: M = 7.88 SD = 7.55, concussed: M = 13.4 SD = 11.42), (t[103] = −2.53, p = 0.01) and SCARED-P (controls: M = 3.55 SD = 3.62, concussed: M = 6.72 SD = 7.12), (t[103] = −2.42, p < 0.01) scores were higher than controls. SCARED-C/SCARED-P scores were not predictive of high/low symptom report at 30 days post-injury, X2(2, n = 59) = 3.46, p = 0.18. The stepwise LR model was significant, X2(1, n = 105) = 7.34, p = 0.007; SCARED-C scores were predictive of concussion group inclusion, SCARED-P scores were not. In analyses of only patients whose parent reported a mental health history (22/105, 21%), there was no significant difference between control and patients on the SCARED-C, t(20) = −1.82, p = 0.08, or SCARED-P, t(20) = −0.34, p = 0.74. SCARED-C/SCARED-P scores did not predict control/concussion group inclusion, X2(2, n = 22) = 5.04, p = 0.08. Conclusions: SCARED-P/SCARED-C scores effectively differentiated between groups: patients and parents reported higher anxiety symptoms. The inclusion of parents with mental health diagnoses precluded the SCARED from differentiating controls from patients.

Peri-procedural, 30-day and 1 year-outcomes in chronic dialysis patients undergoing transcatheter aortic valve implantation

Background

Patients on chronic dialysis (CD) due to end-stage renal disease (ESRD) with symptomatic severe aortic stenosis eligible for transcatheter aortic valve implantation (TAVI) were excluded from randomized clinical trials. Our study aimed to investigate the outcomes of patients with chronic dialysis who underwent TAVI.

Methods

Single center analysis on prospectively collected data of all consecutive patients who underwent TAVI between January 2011 and December 2020 according to baseline renal function: chronic dialysis group (CD) and control group (CTRL). Procedural, 30-day and 1-year outcomes were assessed. Outcomes were defined in accordance with the VARC-3 criteria.

Results

A total of 875 patients underwent TAVI during the study period, of whom 22 (2.5%) were on chronic dialysis. Patients on CD were younger (median age 80 years, [IQR 73–84] vs 84 years, [IQR 80–87]; p<0.001), more likely to be men [365/863 (42.8%) vs 18/22 (81.8%); p<0.001] and more likely to have peripheral vascular disease [41/853 (4.8%) vs 7/22 (31.8%); p=0.031] and lower body mass index (median 24.1 kg/m2, [IQR 21.5–26.5] vs 26.3 kg/m2, [IQR 23.7–29.3]). Short-term major or life-threatening bleeding were significantly higher in CD patients (odds ratio [95% confidential interval]: 3.67 [1.50–8.96], p 0.005). In contrast, no differences were found regarding rates of vascular complications requiring intervention (OR [95% CI]: 1.35 [0.31–5.90], p=0.662), permanent pacemaker implantation (OR [95% CI]: 0.87 [0.25–2.98], p=1.000) or stroke (OR [95% CI]: 1.51 [0.20–11.64], p=0.504). Importantly, dialysis patients had significantly higher rates of in-hospital, 30-day and 1-year mortality rates (13.6 vs 2.1%, p<0.001; 18.9% vs 2.9, p<0.001 and 26.4% vs 10.7%, p<0.001, respectively). On multivariate analysis, after adjusting for age, gender, relevant co-morbidities, and procedure-related complications, CD remained independently associated with mortality at 1-year. Survival curves during follow up are presented in Figure 1.

Conclusions

Chronic dialysis patients submitted to TAVI had significantly higher rates of short-term life threatening and/or major bleeding, short-term and long-term mortality. Careful selection of patients who would benefit from TAVI among patients with ERDS requiring dialysis is necessary to prevent high rates of postprocedural complications and improve outcomes of this high-risk population.

Funding Acknowledgement

Type of funding sources: None.

Indexing calcium score of the aortic valve to the annulus area improves the grading of aortic stenosis severity in patients within the grey zone of aortic valve calcification

Introduction

Calcium score of the aortic valve (CaScAoV) is recommended as a supporting tool to assist in the grading of aortic stenosis (AS) severity when echocardiographic assessment is inconclusive. However, a significant proportion of patients have CaScAoV values within a “grey zone” between the “unlikely” and “likely” thresholds. The purpose of this study was to assess the potential usefulness of indexing CaScAoV to the area of the aortic annulus, in order to improve the discriminative power of CaScAoV in this subset of patients.

Methods

Consecutive patients evaluated at a single center TAVI program were retrospectively identified and included in the analysis if cardiac CT and echocardiography were performed within a 6-month timeframe. Those with LVEF <50%, indexed stroke volume <35 ml/m2, rheumatic heart disease, or bicuspid aortic valves were excluded. Severe AS was defined as mean transvalvular gradient ≥40 mmHg. The likelihood of severe AS assessed by CT was categorized according to the guideline-recommended sex-specific CaScAoV thresholds. Patients were considered to be in the “grey zone” if their CaScAoV values were between 800–1200 for women, and between 1600–2000 for men.

Results

A total of 655 patients were included (282 men (43.1%), median age 83 years [IQR 79–86]). AS was considered severe by echocardiographic criteria in 587 patients (89.6%), and moderate in the remainder. Median transvalvular gradient was 49 mmHg (IQR 43–59), and median CaScAoV values were 3329 (IQR 2356–4500) for men, and 1995 (IQR 1462–2781) for women.

Overall, 77 patients (11.7%) had CaScAoV values in the “grey zone”, of which 24 (31.2%) had moderate AS (Figure 1). Patients within this region of uncertainty were no different form the others in terms of age, sex, annulus size and body surface area.

In this subset of patients, indexing CaScAoV to aortic annulus area showed good discriminative power to identify severe AS (AUC 0.69, 95% CI 0.56–0.81, p=0.008). Using previously established thresholds (>300 AU/cm2 for women and >500 AU/cm2 for men), 48 patients (62.3%) were correctly reclassified (net reclassification index of 0.45, p=0.03). These findings were similar for both sexes.

Conclusion

In patients undergoing cardiac CT for known or suspected severe AS with CaScAoV values within the “grey zone”, indexing CaScAoV to the area of the aortic annulus improves the classification of AS severity and may decrease diagnostic uncertainty.

Funding Acknowledgement

Type of funding sources: None.

Incremental prognostic value of worsening renal function parameters in addition to the GRACE score in patients with acute coronary syndrome

Background

Baseline renal function, one of the parameters included in the GRACE score, has prognostic relevance in patients admitted for acute coronary syndrome (ACS).

Purpose

The aim of this study was to compare different worsening renal function (WRF) parameters during hospitalization for ACS and their impact on all-cause mortality. Furthermore, we aimed to assess if these parameters had any incremental prognostic value in addition to the GRACE score.

Methods

We conducted a single-center retrospective study enrolling consecutive patients admitted for ACS from January 2016 to December 2018. Estimation of glomerular filtration rate (eGFR) for each patient was calculated based on the CKD-EPI formula. WRF during hospitalization was assessed by means of: serum creatinine (sCr) elevation ≥0,3mg/dL, duplication of the sCr value or maximum sCr value ≥2,0mg/dL.

Results

A total of 555 patients were included (65±13 years old, 72% male). Overall, 402 (72%) had hypertension, 167 (30%) were diabetic, 88 (16%) had left ventricular ejection fraction <40%. Mean GRACE score was 102.7±29.1 and median sCr at baseline was 0.83 mg/dL [0.70; 0.97]. Median length of hospitalization was 4 days [2; 10] and the mean follow-up of 963 days.

Baseline eGFR showed significant correlation with mortality during follow-up (HR 0.742 [95% CI 0.691–0.797] per 10 mL/min/1.73m2 increase in eGRF). Moreover, all WRF parameters showed significant association with all-cause mortality during follow-up on a univariate analysis - p<0,001 (Table 1). Elevation of sCr ≥0,3 mg/dL during hospitalization was the most frequent WRF parameter (210 patients - 38%) and the most sensitive parameter to predict our endpoint, occurring in 56 patients who died during follow-up (sensitivity 66.7%). Both duplication of sCr and absolute sCr ≥2,0mg/dL during hospitalization showed a lower prevalence; however, the majority of patients with one of these findings died during follow-up (51,4% and 68,5%, respectively).

On a multivariate Cox regression analysis, adjusted for the GRACE score, all individual WRF parameters remained independently associated with all-cause mortality during follow up (Table 2).

Conclusion

Worsening renal function has significant prognostic impact in patients admitted for ACS. Identification of these parameters during hospitalization adds significant value to the prognostic stratification of the GRACE score.

Funding Acknowledgement

Type of funding sources: None.

Value of cardiopulmonary exercise test submaximal parameters in the assessment of aortic stenosis patients

Background

Exercise test is recommended for risk stratification of asymptomatic patients with severe aortic stenosis (AS), although a significant number of patients can't perform a maximal exercise test, increasing the potential value of sub-maximal parameters for the assessment of these patients.

Aim

To assess which parameters could be useful for risk stratification in case of a submaximal Cardiopulmonary Exercise Testing (CPET) in asymptomatic patients with severe AS.

Methods

Retrospective evaluation of adult patients with asymptomatic severe AS, in a single center, who underwent CPET between December 2016 and November 2021. All patients underwent a treadmill CPET using an exercise protocol with progressive increase in workload. Patients were divided in group A (maximal CPET) or group B, respectively, if respiratory exchange ratio (RER) was >1.10 at peak exercise or below this value. Known parameters accessed in a submaximal CPET were evaluated: mean minute ventilation/carbon dioxide production slope (VE/VCO2), VO2 value in first ventilatory threshold (VT1), peak circulatory power, and oxygen uptake efficiency slope (OUES).

Results

CPET was performed in 25 patients with severe asymptomatic AS (80 years ± 7 years, 56% male), median AVA was 0.86 cm2 [IQR 0.65–0.95 cm2] and transaortic pressure gradient was 46 mmHg [IQR 41–55 mmHg]. The most used protocol was a ramp slope. Nineteen patients (76%) didn't reach a RER>1.10 (group B) due to respiratory (26%) or peripheral limitation (53%). Comparing both groups, group B patients showed a shorter duration of exercise of (8±3 min vs. 9±4 min, p=0.422), and a lowest mean peak VO2 (16.3±3.6 vs. 20.5±6.9 ml/kg/min, p=0.207). In our population, bivariate analyses demonstrated that OUES was the only submaximal parameter that could discriminate both groups: Group B patients had the lowest values (1.53 [IQR 1.47–1.70] vs. 1.94 [IQR 1.56–2.11], p=0.042). ROC curve analysis of OUES values revealed an AUC of 0.78 (p=0.042) for maximal CPET prediction. The cut-off point with most sensitivity (S) and specificity (E) obtained using the Youden index (0.62) was 1.9 (S≈67%; E≈95%) (Figure 1).

Conclusions

In our cohort of asymptomatic AS patients, even with submaximal CPET, OUES accurately identify patients with higher degrees of functional limitation. Whether OUES is useful as prognostic marker to the workflow treatment of AS it's worth to be assessed prospectively.

Funding Acknowledgement

Type of funding sources: None.

Cardiopulmonary exercise testing in Fontan patients: unmasking the secret of Super-Fontans

Background

Exercise capacity is usually reduced in Fontan patients, however there is a subset of patients who have normal exercise capacity and better outcomes, the “Super-Fontans”. The aim of this study was to characterize a cohort of Fontan patients undergoing cardiopulmonary exercise testing (CPET) and identify predictors of better functional capacity.

Methods

Single center retrospective analysis of consecutive Fontan patients aged >10 years old who underwent CPET, between March 2018 and May 2021.

Peak respiratory exchange ratio1.05 defined maximal CPET. Peak VO2 (pVO2) as a percentage of its predicted value was used as reference value to stratify patients in tertiles.

Patients in 3rd tertile, with a percentage predicted pVO2 superior to 75%, were considered good-performers.

Blood tests and transthoracic echocardiogram (TTE) were performed on the same day. Additional data were collected from electronic charts.

Results

In total, 49 patients were included (mean age 19±7 years old, 67% male) with intra or extracardiac conduit implanted in mean 12±7 years prior to the CPET.

The most common primary diagnoses were tricuspid/pulmonary atresia (43%), followed by unbalanced complete AV septal defect (14%) and double inlet left ventricle (14%). 12 patients had a systemic right ventricle. All, except 5 patients, had preserved systolic ventricular function and 37% had moderate to severe AV regurgitation.

The majority had normal hemoglobin levels (median 15.6 g/dL), hepatic enzymes (median total bilirubin 0.8 mg/dL), renal function (median creatinine 0.8 mg/dL) and low NT-proBNP (median 122 pg/mL).

All patients had maximal CPET, median %VO2 at VT1 was 57% of peak and mean pVO2 was 66±14% of the predicted. Most patients (69%) showed exercise limitation due to cardiovascular cause, followed by O2 desaturation, present in 22% of CPETs. The age of Fontan completion was not associated with functional capacity (p=0.6).

The good-performer group comprised 13 patients (27%), all in sinus rhythm, of which 10 were physically active. Compared with the remainder, this group had higher VO2 at VT1 (18.7 vs. 14.6, p=0.01) and VO2 at VT2 (25.9 vs. 22.1, p=0.02), both in mL/kg/min. Also, peak heart rate (% predicted) (90 vs. 81, p=0.03) was higher in this subgroup – fig.1. Conversely, differences on TTE parameters (GLS and AV valve regurgitation) and blood biomarkers were not statistically significant. On multivariable analysis, no single variable predicted better functional capacity.

Conclusion

In our Fontan cohort, most patients had reduced exercise capacity, largely due to cardiovascular dysfunction. However, “Super-Fontans” stood out as they had a higher anaerobic threshold illustrating their better physical condition. These findings highlight the role of regular physical activity in Fontan patients as a cornerstone for better functional capacity.

Funding Acknowledgement

Type of funding sources: None.

Molecular and functional diversity of neural connexins in the retina

Electrical synapses (gap junctions) in neuronal circuits have become a major focus in the study of network properties such as synchronization and oscillation (Galarreta and Hestrin, 1999; Gibson et al., 1999). Despite the recent progress made in unraveling the contribution of gap junctions to network behavior, little is known about the molecular composition of the junctional constituents. By cloning gap junction proteins [connexins (Cxs)] from zebrafish retina and through functional expression, we demonstrate that the retina possesses a high degree of connexin diversity, which may account for differential functional properties of electrical synapses. Three new Cxs, designated as zebrafish Cx27.5 (zfCx27.5), zfCx44.1, and zfCx55.5, and the carp ortholog of mammalian Cx43 were cloned. By in situ hybridization and in situ RT-PCR, we demonstrate that the four fish connexin mRNAs show differential localization in the retina. Transient functional expression in paired Xenopus oocytes and in the neuroblastoma N2A cell line indicate an extreme range of electrophysiological properties of these connexins in terms of voltage dependence and unitary conductance. For instance, the new zfCx44.1 exhibited high sensitivity to voltage-induced closure with currents decaying rapidly for transjunctional potentials >10 mV, whereas zfCx55.5 channels showed an opposite voltage dependence in response to voltage steps of either polarity. Moreover, although zfCx44.1 channels showed unitary conductance as high as any previously reported for junctional channels (nearly 300 pS), zfCx55. 5 and zfCx27.5 exhibited much lower unitary conductances (<60 pS).

A cardiac magnetic resonance myocardial strain patterns analysis in left bundle branch block

Funding Acknowledgements

Type of funding sources: None.

Introduction

Recently, a classification with four types of septal longitudinal strain patterns was described using a speckle tracking based strain analysis in echocardiography suggesting pathophysiological continuum of LBBB-induced LV remodeling. Little data exist on feature tracking cardiac magnetic resonance (FT-CMR) in LBBB patients, and whether such patterns could be reproduced in CMR is not established yet.

Purpose

In this study, we aimed to: 1) Assess and reproduce the new strain patterns classification by CMR and 2) Evaluate its association with LV remodeling and myocardial scar in a LBBB cohort.

Methods

Single center registry which included LBBB patients with septal flash (SF) referred to CMR to assess the structural cause of LV dysfunction. LBBB was defined according to Strauss criteria as strict LBBB, non-strict LBBB or nonspecific LV conduction delay.

A semi-automated FT-CMR was used to quantify myocardial strain and detect the four septal longitudinal and radial strain patterns, according to the recent classification (LBBB-1 through LBBB-4) – Figure. Extent of SF was visually scored as mild, moderate, or prominent.

Results

A total of 115 patients were included (mean age 66±11 years; 57% men; 38% with ischemic heart disease). Median duration of QRS was 150± 26ms and majority of the patients (n=90, 78%) were classified as strict LBBB.

In longitudinal strain analyses LBBB-1 was observed in 23 (20%), LBBB-2 in 37 (32.1%), LBBB-3 in 25 (21.7%), and LBBB-4 in 30 (26%) patients. Patients at higher LBBB stages (longitudinal or radial pattern) had more prominent septal flash, greater LV volumes, lower LV ejection fraction and lower absolute global longitudinal, circumferential and radial strain values compared with patients in less advanced stages (p &lt; 0.05 for all) - table.

There was no difference between patterns in clinical characteristics, ischemic etiology, QRS duration and time delay between septal and lateral LV wall.

Late gadolinium enhancement (LGE) was found in 63 patients (54.8%), with a septal location in 34 (29.6%) patients, lateral in 4 (3.5%) patients, septal and lateral in 11 (9.6%) patients. Furthermore, no difference was found for LGE presence, distribution or location between the four strain patterns.

Conclusions

Among patients with LBBB, our study found a good association between longitudinal and radial strain patterns with the degree of LV remodeling and LV dysfunction by FT-CMR analysis. Additionally, myocardial fibrosis didn’t seem to interfere with the staged LBBB classification.

Potential impact of replacing SCORE with SCORE-2 on risk classification and statin eligibility – a coronary calcium score correlation study

Background

Recently, the European Society of Cardiology issued new algorithms to estimate the 10-year risk of atherosclerotic cardiovascular disease (ASCVD), along with new age-specific thresholds to classify individuals as low-to-moderate, high, or very-high risk.

The aim of this study was to compare the latest SCORE-2 model with the older SCORE (Systematic COronary Risk Evaluation) in their ability to identify individuals with high coronary artery calcium score (CACS), and assess the relationship between potential eligibility for statin therapy and CACS.

Methods

Individuals 40–69 years old without diabetes or known ASCVD were identified in a single center registry of patients undergoing CACS and coronary CT angiography for suspected coronary artery disease. SCORE and SCORE-2 were calculated and used with each patient's untreated LDL-C values to assess eligibility for statin therapy. High CACS was defined as an Agatston score ≥100.

Results

A total of 389 pts (46% men, mean age 58±8 years) were included, of which 15% (n=60) were active smokers. The mean systolic blood pressure and untreated LDL-C values were 136±17 mmHg and 155±65 mg/dL, respectively.

The proportion of patients classified as low-to-moderate risk, high risk, and very high risk was 93%, 6% and 1% using the SCORE algorithm, and 42%, 44%, and 14% using SCORE-2, respectively. Overall, 218 patients (56%) would have their risk category revised upwards, while no patients would be downgraded.

The median CACS was 5 (IQR 0–71 AU), with 166 patients (43%) having CACS = 0, and 81 (21%) presenting CACS values ≥100.

SCORE and SCORE-2 showed similar discriminative power to identify patients with CACS ≥100 (C-statistic 0.77, 95% CI 0.71–0.82, vs. 0.75, 95% CI 0.69–0.80, P=0.109 for comparison]. The up-reclassification of risk conveyed by SCORE-2 affected patients across all categories of CACS (Fig. 1).

The proportion of patients in whom statin therapy would generally be indicated was higher with the SCORE-2 criteria vs. the SCORE algorithm (61% vs. 29%, respectively, p&lt;0.001). The broadening of potential indication for statin therapy spanned all categories of CACS, including patients with CACS = 0 (Fig. 2).

Conclusion

Even though the discriminative power of SCORE-2 is similar to the older SCORE, the introduction of age-specific thresholds results in the up-reclassification of risk in roughly half of the patients. The application of SCORE-2 will broaden statin eligibility overall, not only in patients with high atherosclerotic burden, but also in those with CACS = 0. These findings support the use of risk modifiers in selected patients to improve the effectiveness of statin therapy.

Funding Acknowledgement

Type of funding sources: None.