End-stage heart failure in congenitally corrected transposition of the great arteries: a multicentre study.

BACKGROUND AND AIMS: For patients with congenitally corrected transposition of the great arteries (ccTGA), factors associated with progression to end-stage congestive heart failure (CHF) remain largely unclear. METHODS: This multicentre, retrospective cohort study included adults with ccTGA seen at a congenital heart disease centre. Clinical data from initial and most recent visits were obtained. The composite primary outcome was mechanical circulatory support, heart transplantation, or death. RESULTS: From 558 patients (48% female, age at first visit 36 ± 14.2 years, median follow-up 8.7 years), the event rate of the primary outcome was 15.4 per 1000 person-years (11 mechanical circulatory support implantations, 12 transplantations, and 52 deaths). Patients experiencing the primary outcome were older and more likely to have a history of atrial arrhythmia. The primary outcome was highest in those with both moderate/severe right ventricular (RV) dysfunction and tricuspid regurgitation (n = 110, 31 events) and uncommon in those with mild/less RV dysfunction and tricuspid regurgitation (n = 181, 13 events, P < .001). Outcomes were not different based on anatomic complexity and history of tricuspid valve surgery or of subpulmonic obstruction. New CHF admission or ventricular arrhythmia was associated with the primary outcome. Individuals who underwent childhood surgery had more adverse outcomes than age- and sex-matched controls. Multivariable Cox regression analysis identified older age, prior CHF admission, and severe RV dysfunction as independent predictors for the primary outcome. CONCLUSIONS: Patients with ccTGA have variable deterioration to end-stage heart failure or death over time, commonly between their fifth and sixth decades. Predictors include arrhythmic and CHF events and severe RV dysfunction but not anatomy or need for tricuspid valve surgery.

Combating DC-SIGN-mediated SARS-CoV-2 dissemination by glycan-mimicking polymers.

Many viruses exploit the human C-type lectin receptor dendritic cell-specific ICAM-3 grabbing nonintegrin (DC-SIGN) for cell entry and virus dissemination. An inhibition of DC-SIGN-mediated virus attachment by glycan-derived ligands has, thus, emerged as a promising strategy toward broad-spectrum antiviral therapeutics. In this contribution, several cognate fragments of oligomannose- and complex-type glycans grafted onto a poly-l-lysine scaffold are evaluated as polyvalent DC-SIGN ligands. The range of selected carbohydrate epitopes encompasses linear (α- d-Man-(1→2)-α- d-Man, α- d-Man-(1→2)-α- d-Man-(1→2)-α- d-Man-(1→3)-α- d-Man) and branched (α- d-Man-(1→6)-[α- d-Man-(1→3)]-α- d-Man) oligomannosides, as well as α- l-Fuc. The thermodynamics of binding are investigated on a mono- and multivalent level to shed light on the molecular details of the interactions with the tetravalent receptor. Cellular models of virus attachment and DC-SIGN-mediated virus dissemination reveal a high potency of the presented glycopolymers in the low pico- and nanomolar ranges, respectively. The high activity of oligomannose epitopes in combination with the biocompatible properties of the poly- l-lysine scaffold highlights the potential for further preclinical development of polyvalent DC-SIGN ligands.

Assessment of Hypertension, Guideline-Directed Counseling, and Outcomes in the ACHD Population.

Guidelines for the diagnosis and treatment of hypertension were published by the American Heart Association (AHA) in 2017. The prevalence of hypertension in adults with congenital heart disease (ACHD) under these guidelines has yet to be characterized. We sought to assess the prevalence, impact, and provider response to hypertension under current guidelines. Data were obtained retrospectively from records of routine clinic visits over a 10 year period. Potential hypertension-related adverse outcomes including stroke, myocardial infarction, surgical intervention for aortic aneurysm, aortic dissection, atrial fibrillation or flutter, cardiac transplantation and death were recorded. The 1070 patients who met inclusion criteria had a mean age of 30.8 ± 10.0 years. The prevalence of hypertension under the 2017 guidelines was 46.6%. Multivariate modeling identified cyanosis, male gender, older age, and overweight/obesity as independent risk factors for hypertension. Guideline-directed management of hypertension in ACHD patients occurred more frequently in ACHD and adult cardiology clinics than in pediatric cardiology clinics (44.1% and 45.1% vs. 24.0%, p < 0.01, respectively). Adverse outcomes were reported in 217 (20%) patients, the most prevalent of which was atrial fibrillation or flutter (11%). Multivariable modelling for any adverse outcome identified older age, hypertension, cyanosis, greater complexity ACHD, and obesity as risk factors. Modifiable risk factors for atherosclerotic cardiovascular disease are common and often under addressed in the ACHD population.

Sweet Drugs for Bad Bugs: A Glycomimetic Strategy against the DC-SIGN-Mediated Dissemination of SARS-CoV-2.

The C-type lectin receptor DC-SIGN is a pattern recognition receptor expressed on macrophages and dendritic cells. It has been identified as a promiscuous entry receptor for many pathogens, including epidemic and pandemic viruses such as SARS-CoV-2, Ebola virus, and HIV-1. In the context of the recent SARS-CoV-2 pandemic, DC-SIGN-mediated virus dissemination and stimulation of innate immune responses has been implicated as a potential factor in the development of severe COVID-19. Inhibition of virus binding to DC-SIGN, thus, represents an attractive host-directed strategy to attenuate overshooting innate immune responses and prevent the progression of the disease. In this study, we report on the discovery of a new class of potent glycomimetic DC-SIGN antagonists from a focused library of triazole-based mannose analogues. Structure-based optimization of an initial screening hit yielded a glycomimetic ligand with a more than 100-fold improved binding affinity compared to methyl α-d-mannopyranoside. Analysis of binding thermodynamics revealed an enthalpy-driven improvement of binding affinity that was enabled by hydrophobic interactions with a loop region adjacent to the binding site and displacement of a conserved water molecule. The identified ligand was employed for the synthesis of multivalent glycopolymers that were able to inhibit SARS-CoV-2 spike glycoprotein binding to DC-SIGN-expressing cells, as well as DC-SIGN-mediated trans-infection of ACE2+ cells by SARS-CoV-2 spike protein-expressing viruses, in nanomolar concentrations. The identified glycomimetic ligands reported here open promising perspectives for the development of highly potent and fully selective DC-SIGN-targeted therapeutics for a broad spectrum of viral infections.

Prediction and Validation of a Druggable Site on Virulence Factor of Drug Resistant Burkholderia cenocepacia*.

Burkholderia cenocepacia is an opportunistic Gram-negative bacterium that causes infections in patients suffering from chronic granulomatous diseases and cystic fibrosis. It displays significant morbidity and mortality due to extreme resistance to almost all clinically useful antibiotics. The bacterial lectin BC2L-C expressed in B. cenocepacia is an interesting drug target involved in bacterial adhesion and subsequent deadly infection to the host. We solved the first high resolution crystal structure of the apo form of the lectin N-terminal domain (BC2L-C-nt) and compared it with the ones complexed with carbohydrate ligands. Virtual screening of a small fragment library identified potential hits predicted to bind in the vicinity of the fucose binding site. A series of biophysical techniques and X-ray crystallographic screening were employed to validate the interaction of the hits with the protein domain. The X-ray structure of BC2L-C-nt complexed with one of the identified active fragments confirmed the ability of the site computationally identified to host drug-like fragments. The fragment affinity could be determined by titration microcalorimetry. These structure-based strategies further provide an opportunity to elaborate the fragments into high affinity anti-adhesive glycomimetics, as therapeutic agents against B. cenocepacia.

Differences in perceptions of transition readiness between parents and teens with congenital heart disease: do parents and teens agree?

BACKGROUND: Amongst patients with CHD, the time of transition to adulthood is associated with lapses in care leading to significant morbidity. The purpose of this study was to identify differences in perceptions between parents and teens in regard to transition readiness. METHODS: Responses were collected from 175 teen-parent pairs via the validated CHD Transition Readiness survey and an information request checklist. The survey was distributed via an electronic tablet at a routine clinic visit. RESULTS: Parents reported a perceived knowledge gap of 29.2% (the percentage of survey items in which a parent believes their teen does not know), compared to teens self-reporting an average of 25.9% of survey items in which they feel deficient (p = 0.01). Agreement was lowest for long-term medical needs, physical activities allowed, insurance, and education. In regard to self-management behaviours, agreement between parent and teen was slight to moderate (weighted κ statistic = 0.18 to 0.51). For self-efficacy, agreement ranged from slight to fair (weighted κ = 0.16 to 0.28). Teens were more likely to request information than their parents (79% versus 65% requesting at least one item) particularly in regard to pregnancy/contraception and insurance. CONCLUSION: Parents and teens differ in several key perceptions regarding knowledge, behaviours, and feelings related to the management of heart disease. Specifically, parents perceive a higher knowledge deficit, teens perceive higher self-efficacy, and parents and teens agree that self-management is low.

Transition Readiness in Teens and Young Adults with Congenital Heart Disease: Can We Make a Difference?

OBJECTIVES: To examine changes in transition readiness (knowledge, self-efficacy, self-management) over time and explore factors associated with transition readiness, including psychosocial quality of life (QOL) and health service utilization in teens/young adults with congenital heart disease. STUDY DESIGN: In a multicenter prospective cohort study, 356 patients, age 14-27 years, completed transition readiness and QOL assessments at routine cardiology visits at baseline and 1-year follow-up. RESULTS: Median patient age was 19.8 years at 1.03 years (IQR 0.98-1.24) following baseline transition readiness assessment. Average knowledge deficit scores decreased at follow-up (P < .0001) and self-efficacy scores increased (P < .0001). Self-management scores increased (P < .0001), but remained low (mean 57.7, 100-point scale). Information was requested by 73% of patients at baseline and was associated with greater increase in knowledge at follow-up (P = .005). Increased knowledge (P = .003) and perceived self-efficacy (P = .01) were associated with improved psychosocial QOL, but not health service utilization at follow-up. Patients who preferred face-to-face information from healthcare providers (47%) vs other information sources were more likely to request information (P < .0001). In patients <18 years old, greater agreement between teen and parental perception of teen's knowledge was associated with greater increase in patient knowledge (P = .02) and self-efficacy (P = .003). CONCLUSION: Transition readiness assessment demonstrated improved knowledge, self-efficacy, and self-management at 1-year follow-up in teens/young adults with congenital heart disease. Improved knowledge and self-efficacy were associated with improved psychosocial QOL. Self-management remained low. Supplemental media for conveying information and greater involvement of parents may be needed to optimize transition readiness.

How Nothing Boosts Affinity: Hydrophobic Ligand Binding to the Virtually Vacated S1' Pocket of Thermolysin.

We investigated the hydration state of the deep, well-accessible hydrophobic S1' specificity pocket of the metalloprotease thermolysin with purposefully designed ligands using high-resolution crystallography and isothermal titration calorimetry. The S1' pocket is known to recognize selectively a very stringent set of aliphatic side chains such as valine, leucine, and isoleucine of putative substrates. We engineered a weak-binding ligand covering the active site of the protease without addressing the S1' pocket, thus transforming it into an enclosed cavity. Its sustained accessibility could be proved by accommodating noble gas atoms into the pocket in the crystalline state. The topology and electron content of the enclosed pocket with a volume of 141 Å3 were analyzed using an experimental MAD-phased electron density map that was calibrated to an absolute electron number scale, enabling access to the total electron content within the cavity. Our analysis indicates that the S1' pocket is virtually vacated, thus free of any water molecules. The thermodynamic signature of the reduction of the void within the pocket by growing aliphatic P1' substituents (H, Me, iPr, iBu) reveals a dramatic, enthalpy-dominated gain in free energy of binding resulting in a factor of 41 000 in Kd for the H-to-iBu transformation. Substituents placing polar decoy groups into the pocket to capture putatively present water molecules could not collect any evidence for a bound solvent molecule.

A False-Positive Screening Hit in Fragment-Based Lead Discovery: Watch out for the Red Herring.

With the rising popularity of fragment-based approaches in drug development, more and more attention has to be devoted to the detection of false-positive screening results. In particular, the small size and low affinity of fragments drives screening techniques to their limit. The pursuit of a false-positive hit can cause significant loss of time and resources. Here, we present an instructive and intriguing investigation into the origin of misleading assay results for a fragment that emerged as the most potent binder for the aspartic protease endothiapepsin (EP) across multiple screening assays. This molecule shows its biological effect mainly after conversion into another entity through a reaction cascade that involves major rearrangements of its heterocyclic scaffold. The formed ligand binds EP through an induced-fit mechanism involving remarkable electrostatic interactions. Structural information in the initial screening proved to be crucial for the identification of this false-positive hit.

The spectrum of congenital heart disease and outcomes after surgical repair among children with Turner syndrome: a single-center review.

Turner syndrome (TS), a genetic abnormality affecting 1 in 2,500 people, is commonly associated with congenital heart disease (CHD). However, the surgical outcomes for TS patients have not been well described. This study reviewed the spectrum of CHD in TS at the authors' center. The authors report outcomes after coarctation of the aorta (CoA) repair or staged palliation of hypoplastic left heart syndrome (HLHS) and then compare the surgical outcomes with those of non-TS patients undergoing like repair. This retrospective chart review was conducted at the Children's Hospital of Wisconsin from 1999 to 2011. Of the 173 patients with TS, 77 (44.5 %) were found to have CHD. Left-sided obstructive lesions were the most common. However, the spectrum of CHD was wide and included systemic and pulmonary venous abnormalities as well as abnormalities of the coronary arteries. In the comparative analysis of CoA repair, the TS patients younger than 60 days had longer aortic cross-clamp times (24 vs. 16 min; p = 0.001) and longer hospital stays (12 vs. 6 days; p ≤ 0.0001) than the non-TS patients. At the follow-up assessment after 8.8 ± 9.1 years, 17 % of the TS patients had hypertension, but no patient had required reintervention, and no deaths had occurred. Finally, three of the four TS patients with HLHS died within the first year. The spectrum of CHD within TS is wide and not limited to bicuspid aortic valve or CoA. Additionally, patients with TS undergoing CoA repair may have a more challenging early postoperative course but experience outcomes similar to those of non-TS patients. Finally, patients who have TS combined with HLHS remain a challenging population with generally poor survival.

Does size matter? - Comparing pyranoses with septanoses as ligands of the bacterial lectin FimH.

The pharmacological modulation of disease-relevant carbohydrate-protein interactions represents an underexplored area of medicinal chemistry. One particular challenge in the design of glycomimetic compounds is the inherent instability of the glycosidic bond toward enzymatic cleavage. This problem has traditionally been approached by employing S-, N-, or C-glycosides with reduced susceptibility toward glycosidases. The application of ring-extended glycomimetics is an innovative approach to circumvent this issue. On the example of the bacterial adhesin FimH, it was explored how design principles from pyranose glycomimetics transfer to analogous septanose structures. A series of ring-extended FimH antagonists exhibiting the well-proven pharmacophore necessary for targeting the tyrosine-gate of FimH was synthesized. The resulting septanoses were evaluated for their affinity to the conformationally rigid isolated lectin domain of FimH (FimHLD), as well as a structurally flexible full-length FimH (FimHFL) construct. Some elements of potent mannoside-based FimH antagonists could be successfully transferred to septanose-based ligands, ultimately resulting in a 32-fold increase in binding affinity. Interestingly, the canonical ca. 100-fold loss of binding affinity between FimHLD and FimHFL is partly mitigated by the more flexible septanose antagonists, hinting at potentially differing interaction features of the flexible glycomimetics with intermediately populated states during the conformational transition of FimHFL.

Analogues of the pan-selectin antagonist rivipansel (GMI-1070).

The selectin family consisting of E-, P- and L-selectin plays dominant roles in atherosclerosis, ischemia-reperfusion injury, inflammatory diseases, and metastatic spreading of some cancers. An early goal in selectin-targeted drug discovery campaigns was to identify ligands binding to all three selectins, so-called pan-selectin antagonists. The physiological epitope, tetrasaccharide sialyl Lewisx (sLex, 1) binds to all selectins, albeit with very different affinities. Whereas P- and L-selectin require additional interactions contributed by sulfate groups for high binding affinity, E-selectin can functionally bind sLex-modified glycolipids and glycoproteins. Rivipansel (3) marked the first pan-selectin antagonist, which simultaneously interacted with both the sLex and the sulfate binding site. The aim of this contribution was to improve the pan-selectin affinity of rivipansel (3) by leveraging a new class of sLex mimetics in combination with an optimized linker length to the sulfate bearing group. As a result, the pan-selectin antagonist 11b exhibits an approximatively 5-fold improved affinity for E-, as well as P-selectin.

Thermodynamics-Guided Design Reveals a Cooperative Hydrogen Bond in DC-SIGN-targeted Glycomimetics.

Due to the shallow and hydrophilic binding sites of carbohydrate-binding proteins, the design of glycomimetics is often complicated by high desolvation costs as well as competition with solvent. Therefore, a careful optimization of interaction vectors and ligand properties is required in the design and optimization of glycomimetics. Here, we employ thermodynamics-guided design to optimize mannose-based glycomimetics targeting the human C-type lectin receptor dendritic cell-specific intercellular adhesion molecule 3 grabbing nonintegrin (DC-SIGN), a pathogenic host factor in viral infections. By exploring ligand rigidification and hydrogen bond engineering, a monovalent glycomimetic with an unprecedented affinity for DC-SIGN in the low µM range was discovered. A matched molecular pair analysis based on microcalorimetric data revealed a stereospecific hydrogen bond interaction with Glu358/Ser360 as the origin of this cooperative and enthalpically dominated interaction. This detailed insight into the binding mechanism paves the way for an improvement of monovalent glycomimetics targeting DC-SIGN.

Aortic aneurysms remain a significant source of morbidity and mortality after use of Dacron(®) patch aortoplasty to repair coarctation of the aorta: results from a single center.

Aortic aneurysm formation after coarctation repair is a serious and life-threatening complication. Repairs using synthetic materials such as Dacron(®) may carry the highest risk of aneurysm formation and rupture. The authors sought to determine the prevalence of aneurysm formation in patients who previously underwent coarctation repair using Dacron(®) patch aortoplasty at their institution. Between 1977 and 1994, 63 patients underwent isolated coarctation repair using Dacron(®) patch aortoplasty. Aneurysms were defined as an aortic dimension 1.5 times that of the aorta at the level of the diaphragm as shown by angiography, computed tomography (CT) scan, or magnetic resonance imaging (MRI). Of 61 early survivors, 29 (47 %) experienced an aneurysm in the area of previous repair. Nine patients (31 %) had spontaneous rupture of the aneurysm, which caused death in seven cases. Elective or emergent aneurysm repair was performed for 20 patients without complication, and 2 patients are being monitored at this writing. The mean interval from patch placement to aneurysm repair was 15 years (range, 4-27 years). Overall freedom from the development of an aortic aneurysm was 97 % at 5 years, 90 % at 10 years, 69 % at 20 years, and 42 % at 25 years. After repair of coarctation using Dacron(®) patch aortoplasty, the risk for aneurysm formation in the area of repair and death from rupture is extremely high. Therefore, in accordance with the 2008 American Heart Association/American College of Cardiology (AHA/ACC) guidelines, all patients with repaired aortic coarctation should undergo either CT or MRI imaging at least every 5 years to assess for aortic aneurysm formation. More frequent imaging should be obtained for patients previously repaired with Dacron(®) patch aortoplasty.

The role of glycosylation patterns of viral glycoproteins and cell entry receptors in arenavirus infection.

Mammarenaviruses are enveloped RNA viruses that can be associated with rodent-transmitted diseases in humans. Their virions are composed of a nucleocapsid surrounded by a lipid bilayer with glycoprotein (GP) spikes interacting with receptors on target cells. Both the GP and receptors are highly glycosylated, with glycosylation patterns being crucial for virus binding and cell entry, viral tropism, immune responses, or therapy strategies. These effects have been previously described for several different viruses. In case of arenaviruses, they remain insufficiently understood. Thus, it is important to determine the mechanisms of glycosylation of viral proteins and receptors responsible for infection, in order to fully understand the biology of arenaviruses. In this article, we have summarized and critically evaluated the available literature data on the glycosylation of mammarenavirus-associated proteins to facilitate further research in this field.

Synthesis and Binding Mode Predictions of Novel Siglec-7 Ligands.

Siglec-7 regulates immune cell activity and is a promising target for immunomodulation. Here, we report the discovery of novel sialic acid derivatives binding to Siglec-7. Synthesis and affinity measurements are complemented by high-quality models of sialoside-Siglec-7 complexes based on molecular dynamics (MD) simulations on the microsecond time scale. We provide details for the predicted binding modes for the new ligands, e.g., that an extension of the carbon backbone leads to a different molecular interaction pattern with the receptor and the nearby water structure than found for known Siglec-7 ligands. Further on, we uncover some shortcomings of the GLYCAM06 and GAFF2 force fields when used for the simulation of sialoside-based glycomimetics. Our results open new opportunities for the rational design of Siglec-7 inhibitors. In addition, we provide strategies on how to use and visualize MD simulations to describe and investigate sialoside-Siglec complexes in general.

Clinical Outcomes of Adult Fontan-Associated Liver Disease and Combined Heart-Liver Transplantation.

BACKGROUND: The impact of Fontan-associated liver disease (FALD) on post-transplant mortality and indications for combined heart-liver transplant (CHLT) in adult Fontan patients remains unknown. OBJECTIVES: The purpose of this study was to assess the impact of FALD on post-transplant outcomes and compare HT vs CHLT in adult Fontan patients. METHODS: We performed a retrospective-cohort study of adult Fontan patients who underwent HT or CHLT across 15 centers. Inclusion criteria were as follows: 1) Fontan; 2) HT/CHLT referral; and 3) age ≥16 years at referral. Pretransplant FALD score was calculated using the following: 1) cirrhosis; 2) varices; 3) splenomegaly; or 4) ≥2 paracenteses. RESULTS: A total of 131 patients (91 HT and 40 CHLT) were included. CHLT recipients were more likely to be older (P = 0.016), have a lower hemoglobin (P = 0.025), require ≥2 diuretic agents pretransplant (P = 0.051), or be transplanted in more recent decades (P = 0.001). Postmatching, CHLT demonstrated a trend toward improved survival at 1 year (93% vs 74%; P = 0.097) and improved survival at 5 years (86% vs 52%; P = 0.041) compared with HT alone. In patients with a FALD score ≥2, CHLT was associated with improved survival (1 year: 85% vs 62%; P = 0.044; 5 years: 77% vs 42%; P = 0.019). In a model with transplant decade and FALD score, CHLT was associated with improved survival (HR: 0.33; P = 0.044) and increasing FALD score was associated with worse survival (FALD score: 2 [HR: 14.6; P = 0.015], 3 [HR: 22.2; P = 0.007], and 4 [HR: 27.8; P = 0.011]). CONCLUSIONS: Higher FALD scores were associated with post-transplant mortality. Although prospective confirmation of our findings is necessary, compared with HT alone, CHLT recipients were older with higher FALD scores, but had similar survival overall and superior survival in patients with a FALD score ≥2.

Morbidity and Mortality in Adult Fontan Patients After Heart or Combined Heart-Liver Transplantation.

BACKGROUND: An increasing number of adult Fontan patients require heart transplantation (HT) or combined heart-liver transplant (CHLT); however, data regarding outcomes and optimal referral time remain limited. OBJECTIVES: The purpose of this study was to define survivorship post-HT/CHLT and predictors of post-transplant mortality, including timing of referral, in the adult Fontan population. METHODS: A retrospective cohort study of adult Fontan patients who underwent HT or CHLT across 15 centers in the United States and Canada was performed. Inclusion criteria included the following: 1) Fontan; 2) HT/CHLT referral; and 3) age ≥16 years at the time of referral. Date of "failing" Fontan was defined as the earliest of the following: worsening fluid retention, new ascites, refractory arrhythmia, "failing Fontan" diagnosis by treating cardiologist, or admission for heart failure. RESULTS: A total of 131 patients underwent transplant, including 40 CHLT, from 1995 to 2021 with a median post-transplant follow-up time of 1.6 years (Q1 0.35 years, Q3 4.3 years). Survival was 79% at 1 year and 66% at 5 years. Survival differed by decade of transplantation and was 87% at 1 year and 76% at 5 years after 2010. Time from Fontan failure to evaluation (HR/year: 1.23 [95% CI: 1.11-1.36]; P < 0.001) and markers of failure, including NYHA functional class IV (HR: 2.29 [95% CI: 1.10-5.28]; P = 0.050), lower extremity varicosities (HR: 3.92 [95% CI: 1.68-9.14]; P = 0.002), and venovenous collaterals (HR: 2.70 [95% CI: 1.17-6.20]; P = 0.019), were associated with decreased post-transplant survival at 1 year in a bivariate model that included transplant decade. CONCLUSIONS: In our multicenter cohort, post-transplant survival improved over time. Late referral after Fontan failure and markers of failing Fontan physiology, including worse functional status, lower extremity varicosities, and venovenous collaterals, were associated with post-transplant mortality.

COVID-19-Related Thrombotic and Bleeding Events in Adults With Congenital Heart Disease.

Background: Altered coagulation is a striking feature of COVID-19. Adult patients with congenital heart disease (ACHD) are prone to thromboembolic (TE) and bleeding complications. Objectives: The purpose of this study was to investigate the prevalence and risk factors for COVID-19 TE/bleeding complications in ACHD patients. Methods: COVID-19-positive ACHD patients were included between May 2020 and November 2021. TE events included ischemic cerebrovascular accident, systemic and pulmonary embolism, deep venous thrombosis, myocardial infarction, and intracardiac thrombosis. Major bleeding included cases with hemoglobin drop >2 g/dl, involvement of critical sites, or fatal bleeding. Severe infection was defined as need for intensive care unit, endotracheal intubation, renal replacement therapy, extracorporeal membrane oxygenation, or death. Patients with TE/bleeding were compared to those without events. Factors associated with TE/bleeding were determined using logistic regression. Results: Of 1,988 patients (age 32 [IQR: 25-42] years, 47% male, 59 ACHD centers), 30 (1.5%) had significant TE/bleeding: 12 TE events, 12 major bleeds, and 6 with both TE and bleeding. Patients with TE/bleeding had higher in-hospital mortality compared to the remainder cohort (33% vs 1.7%; P < 0.0001) and were in more advanced physiological stage (P = 0.032) and NYHA functional class (P = 0.01), had lower baseline oxygen saturation (P = 0.0001), and more frequently had a history of atrial arrhythmia (P < 0.0001), previous hospitalization for heart failure (P < 0.0007), and were more likely hospitalized for COVID-19 (P < 0.0001). By multivariable logistic regression, prior anticoagulation (OR: 4.92; 95% CI: 2-11.76; P = 0.0003), cardiac injury (OR: 5.34; 95% CI: 1.98-14.76; P = 0.0009), and severe COVID-19 (OR: 17.39; 95% CI: 6.67-45.32; P < 0.0001) were independently associated with increased risk of TE/bleeding complications. Conclusions: ACHD patients with TE/bleeding during COVID-19 infection have a higher in-hospital mortality from the illness. Risk of coagulation disorders is related to severe COVID-19, cardiac injury during infection, and use of anticoagulants.

Sialic Acid Derivatives Inhibit SiaT Transporters and Delay Bacterial Growth.

Antibiotic resistance is a major worldwide concern, and new drugs with mechanistically novel modes of action are urgently needed. Here, we report the structure-based drug design, synthesis, and evaluation in vitro and in cellular systems of sialic acid derivatives able to inhibit the bacterial sialic acid symporter SiaT. We designed and synthesized 21 sialic acid derivatives and screened their affinity for SiaT by a thermal shift assay and elucidated the inhibitory mechanism through binding thermodynamics, computational methods, and inhibitory kinetic studies. The most potent compounds, which have a 180-fold higher affinity compared to the natural substrate, were tested in bacterial growth assays and indicate bacterial growth delay in methicillin-resistant Staphylococcus aureus. This study represents the first example and a promising lead in developing sialic acid uptake inhibitors as novel antibacterial agents.