Persistent Impairment in Immune Reconstitution and Worse Survival Outcomes in Allogeneic Stem Cell Transplantation Patients with Early Coronavirus Disease 2019 Infection

Patients undergoing allogenic hematopoietic stem cell transplantation (HSCT) are at an increased risk of mortality due to transplantation-related complications in the first year post-transplantation, owing in part to the profound immune dysregulation with T cell and B cell lymphopenia and functional impairment. Although several large studies have reported higher mortality rates from Coronavirus disease 2019 (COVID-19) in HSCT recipients, to date no study has focused on the impact of early COVID-19 infection on immune reconstitution post-transplantation and the correlation with transplantation outcomes. We retrospectively analyzed 61 consecutive adult patients who underwent their first allogeneic HSCT at our institution. Thirteen patients (21.3%) experienced early COVID-19 infection, with a median time to diagnosis of 100 days post-transplantation. In multivariable analysis, patients with early COVID-19 infection had significantly worse overall survival (adjusted hazard ratio [aHR], 4.06; 95% confidence interval [CI], 1.26 to 13.05; P = .019) and progression-free survival (aHR, 6.68; 95% CI, 2.11 to 21.11; P = .001). This was attributed mainly to higher nonrelapse mortality (NRM) among early COVID-19 patients (P = .042). Allogeneic HSCT recipients with early COVID-19 infection had significant delays in absolute lymphocyte count (95% CI, -703.69 to -56.79; P = .021), CD3+CD4+ cell (95% CI, -105.35 to -11.59; P = .042), CD3+CD8+ cell (95% CI, -324.55 to -57.13; P = .038), and CD3-CD56+ cell (95% CI, -193.51 to -47.31; P = .014) recovery compared to those without early COVID-19 infection. Our findings suggest that patients with early COVID-19 infection after allogeneic HSCT have higher NRM and worse survival, at least in part due to impaired immune reconstitution post-transplantation.

Deviations in RSV epidemiological patterns and population structures in the United States following the COVID-19 pandemic

Respiratory Syncytial Virus (RSV) is a leading cause of acute respiratory tract infection, with the greatest impact on infants, immunocompromised individuals, and older adults. RSV prevalence decreased substantially in the United States (US) following the implementation of COVID-19-related non-pharmaceutical interventions but later rebounded with abnormal seasonality. The biological and epidemiological factors underlying this altered behavior remain poorly defined. In this retrospective cohort study from 2009 to 2023 in Chicago, Illinois, US, we examined RSV epidemiology, clinical severity, and genetic diversity. We found that changes in RSV diagnostic platforms drove increased detections in outpatient settings post-2020 and that hospitalized adults infected with RSV-A were at higher risk of intensive care admission than those with RSV-B. While population structures of RSV-A remained unchanged, RSV-B exhibited a genetic shift into geographically distinct clusters. Mutations in the antigenic regions of the fusion protein suggest convergent evolution with potential implications for vaccine and therapeutic development.

The burden of RSV, hMPV, and PIV amongst hospitalized adults in the United States from 2016 to 2019

BACKGROUND

Respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and parainfluenza virus (PIV) hospitalize many people yearly. Though severe lower respiratory tract disease has been described in children, the elderly, and the immunocompromised, there is a gap in our understanding of RSV, hMPV, and PIV in hospitalized adults. We sought to evaluate the association of RSV, hMPV, and PIV with severe respiratory disease requiring noninvasive or mechanical ventilation and death in hospitalized adults in the United States.

METHODS

We conducted a retrospective, pooled, cross-sectional study of general medicine hospitalizations in the United States from 2016 to 2019 using the National Inpatient Sample published by the Agency for Healthcare Quality and Research. We used multivariable Poisson regression to estimate the likelihood of severe respiratory disease or death. We used linear regression to estimate the mean difference in length of stay for those hospitalized with and without a respiratory virus.

RESULTS

We found that RSV (incidence rate ratio [IRR]: 1.68, 95% confidence interval [CI]: 1.61-1.74, p < .001), hMPV (IRR: 1.82, 95% CI: 1.71-1.93, p < .001), and PIV (IRR: 1.81, 95% CI: 1.68-1.94, p < .001) were independently associated with severe respiratory disease, even after adjustment. Additionally, we found the presence of a respiratory virus prolonged hospitalizations by (0.79 ± 0.27 days, p < .003) for RSV, (0.88 ± 0.28 days, p < .002) for hMPV, and (1.43 ± 0.30 days, p < .001) for PIV.

CONCLUSIONS

RSV, hMPV, and PIV have a significant burden on hospitalized adults, even without classic risk factors.

ChatGPT Provides Unsatisfactory Responses to Frequently Asked Questions Regarding Anterior Cruciate Ligament Reconstruction

PURPOSE

To determine whether the free online artificial intelligence platform ChatGPT could accurately, adequately, and appropriately answer questions regarding anterior cruciate ligament (ACL) reconstruction surgery.

METHODS

A list of 10 questions about ACL surgery was created based on a review of frequently asked questions that appeared on websites of various orthopaedic institutions. Each question was separately entered into ChatGPT (version 3.5), and responses were recorded, scored, and graded independently by 3 authors. The reading level of the ChatGPT response was calculated using the WordCalc software package, and readability was assessed using the Flesch-Kincaid grade level, Simple Measure of Gobbledygook index, Coleman-Liau index, Gunning fog index, and automated readability index.

RESULTS

Of the 10 frequently asked questions entered into ChatGPT, 6 were deemed as unsatisfactory and requiring substantial clarification; 1, as adequate and requiring moderate clarification; 1, as adequate and requiring minor clarification; and 2, as satisfactory and requiring minimal clarification. The mean DISCERN score was 41 (inter-rater reliability, 0.721), indicating the responses to the questions were average. According to the readability assessments, a full understanding of the ChatGPT responses required 13.4 years of education, which corresponds to the reading level of a college sophomore.

CONCLUSIONS

Most of the ChatGPT-generated responses were outdated and failed to provide an adequate foundation for patients' understanding regarding their injury and treatment options. The reading level required to understand the responses was too advanced for some patients, leading to potential misunderstanding and misinterpretation of information. ChatGPT lacks the ability to differentiate and prioritize information that is presented to patients.

CLINICAL RELEVANCE

Recognizing the shortcomings in artificial intelligence platforms may equip surgeons to better set expectations and provide support for patients considering and preparing for ACL reconstruction.

Into the unknown: The end of the coronavirus disease 2019 public health emergency in the United States and potential impacts on organ transplant recipients

The public health emergency for coronavirus disease 2019 ended on April 11, 2023, 1 month earlier than its planned termination. The hasty cessation of emergency measures may negatively impact the care of solid organ transplant recipients and other immunosuppressed hosts. Accelerated pathways for drug and vaccine approvals, research funding, and insurance coverage for medical therapies and diagnostic testing are likely to be affected. Health care disparities that characterized the early pandemic may again be intensified. It is imperative that the transplant community promptly anticipate the impact of these changes and prepare accordingly to avoid disruptions in care for the most vulnerable patients.

Association of Systemic Hormonal Contraceptives With Reconstruction Procedures for Patellar Instability

Background

Previous research suggests that estrogen plays a role in increased ligamentous laxity observed within the female population. Whereas many studies have sought to evaluate the impact of exogenous estrogen on anterior cruciate ligament injuries, research has not yet explored its impact on the medial patellofemoral ligament. Furthermore, less is known about the role of exogenous progesterone on ligamentous structures.

Purpose

To determine whether women prescribed systemic estrogen (ethinyl estradiol) or progesterone (norgestimate or etonogestrel) hormonal contraceptives had an increased risk of undergoing reconstruction surgery for patellar instability compared with women without a prescription for systemic hormonal contraceptives.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

The TriNetX Research Network database was queried using International Classification of Disease and Common Procedural Terminology codes for women aged 15 to 26 years who underwent reconstruction procedures for patellar instability between 2012 and 2022. Women were grouped according to whether they had a coded prescription for a systemic hormonal contraceptive containing either ethinyl estradiol or etonogestrel; controls were matched by age, sex, race, and ethnicity. The relative risk (RR) of undergoing reconstruction for patellar instability was determined for each contraceptive.

Results

After 1-to-1 propensity score matching, 0.054% (525/980,878) of women prescribed a systemic contraceptive containing ethinyl estradiol underwent reconstruction procedures for patellar instability compared with 0.043% (417/980,878) of controls (RR, 1.3; 95% CI, 1.1-1.4; P = .0004). Likewise, 0.058% (67/116,260) of women prescribed a form of systemic contraceptive containing only etonogestrel underwent reconstruction procedures for patellar instability compared with 0.026% (30/116,260) of controls (RR, 2.2; 95% CI, 1.5-3.4; P = .0002).

Conclusion

Female patients prescribed systemic contraceptives containing estrogen or progesterone had an increased rate of reconstruction procedures for patellar instability.

Diagnosis, Prognosticators, and Management of Acute Invasive Fungal Rhinosinusitis: Multidisciplinary Consensus Statement and Evidence-Based Review with Recommendations

BACKGROUND

Acute invasive fungal sinusitis (AIFS) is an aggressive disease that requires prompt diagnosis and multidisciplinary treatment given its rapid progression. However, there is currently no consensus on diagnosis, prognosis, and management strategies for AIFS, with multiple modalities routinely employed. The purpose of this multi-institutional and multidisciplinary evidence-based review with recommendations (EBRR) is to thoroughly review the literature on AIFS, summarize the existing evidence, and provide recommendations on the management of AIFS.

METHODS

The PubMed, EMBASE, and Cochrane databases were systematically reviewed from inception through January 2022. Studies evaluating management for orbital, non-sinonasal head and neck, and intracranial manifestations of AIFS were included. An iterative review process was utilized in accordance with EBRR guidelines. Levels of evidence and recommendations on management principles for AIFS were generated.

RESULTS

A review and evaluation of published literature was performed on 12 topics surrounding AIFS (signs and symptoms, laboratory and microbiology diagnostics, endoscopy, imaging, pathology, surgery, medical therapy, management of extrasinus extension, reversing immunosuppression, and outcomes and survival). The aggregate quality of evidence was varied across reviewed domains.

CONCLUSION

Based on the currently available evidence, judicious utilization of a combination of history and physical examination, laboratory and histopathologic techniques, and endoscopy provide the cornerstone for accurate diagnosis of AIFS. In addition, AIFS is optimally managed by a multidisciplinary team via a combination of surgery (including resection whenever possible), antifungal therapy, and correcting sources of immunosuppression. Higher quality (i.e., prospective) studies are needed to better define the roles of each modality and determine diagnosis and treatment algorithms.

Vancomycin Powder Is Highly Cost-Effective in Total Ankle Arthroplasty

Prosthetic joint infection (PJI) is a costly and potentially fatal complication in total ankle arthroplasty (TAA). Some surgeons apply topical vancomycin powder to minimize the risk of infection during TAA procedures. The purpose of our study was to determine the cost-effectiveness of using vancomycin powder to prevent PJI following TAA and to propose an economic model that can be applied by foot and ankle surgeons in their decision to incorporate vancomycin powder in practice. Using our institution's records of the cost of 1 g of topical vancomycin powder, we performed a break-even analysis and calculated the absolute risk reduction and number needed to treat for varying costs of vancomycin powder, PJI infection rates, and costs of TAA revision. Costing $3.06 per gram at our institution, vancomycin powder was determined to be cost-effective in TAA if the PJI rate of 3% decreased by an absolute risk reduction of 0.02% (Number Needed to Treat = 5304). Furthermore, our results indicate that vancomycin powder can be highly cost-effective across a wide range of costs, PJI infection rates, and varying costs of TAA revision. The use of vancomycin powder remained cost-effective even when (1) the price of vancomycin powder was as low as $2.50 to as high as $100.00, (2) infection rates ranged from .05 to 3%, and (3) the cost of the TAA revision procedure ranged from $1000 to $10 000.Levels of Evidence: IV.

Improving Randomized-Controlled Trials in Foot and Ankle Orthopaedics: The Need to Include Sociodemographic Patient Data

BACKGROUND

The representation of sociodemographic data within randomized-controlled trials (RCT) regarding foot and ankle surgery is undefined. The purpose of this study was to determine the incidence of sociodemographic data being reported in contemporary foot and ankle RCTs.

METHODS

Randomized-controlled trials within the PubMed database from 2016 to 2021 were searched and the full text of 40 articles was reviewed to identify sociodemographic variables reported in the manuscript. Data regarding race, ethnicity, insurance status, income, work status, and education were collected.

RESULTS

Race was reported in the results in 4 studies (10.0%), ethnicity in 1 (2.5%), insurance status in 0 (0%), income in 1 (2.5%), work status in 3 (7.5%) and education in 2 (5.0%). In any section other than the results, race was reported in 6 studies (15.0%), ethnicity in 1 (2.5%), insurance status in 3 (7.5%), income in 6 (15.0%), work status in 6 (15.0%), and education in 3 (7.5%). There was no difference in sociodemographic data by journal (P = .212), year of publication (P = .216), or outcome study (P = .604).

CONCLUSION

The overall rate of sociodemographic data reported in foot and ankle RCTs is low. There was no difference in the reporting of sociodemographic data between journal, year of publication, or outcome study.

LEVEL OF EVIDENCE

Level II.

Modeling of the Tricuspid Valve and Right Ventricle in Hypoplastic Left Heart Syndrome With a Fontan Circulation

BACKGROUND

In hypoplastic left heart syndrome, tricuspid regurgitation (TR) is associated with circulatory failure and death. We hypothesized that the tricuspid valve (TV) structure of patients with hypoplastic left heart syndrome with a Fontan circulation and moderate or greater TR differs from those with mild or less TR, and that right ventricle volume is associated with TV structure and dysfunction.

METHODS

TV of 100 patients with hypoplastic left heart syndrome and a Fontan circulation were modeled using transthoracic 3-dimensional echocardiograms and custom software in SlicerHeart. Associations of TV structure to TR grade and right ventricle function and volume were investigated. Shape parameterization and analysis was used to calculate the mean shape of the TV leaflets, their principal modes of variation, and to characterize associations of TV leaflet shape to TR.

RESULTS

In univariate modeling, patients with moderate or greater TR had larger TV annular diameters and area, greater annular distance between the anteroseptal commissure and anteroposterior commissure, greater leaflet billow volume, and more laterally directed anterior papillary muscle angles compared to valves with mild or less TR (all P<0.001). In multivariate modeling greater total billow volume, lower anterior papillary muscle angle, and greater distance between the anteroposterior commissure and anteroseptal commissure were associated with moderate or greater TR (P<0.001, C statistic=0.85). Larger right ventricle volumes were associated with moderate or greater TR (P<0.001). TV shape analysis revealed structural features associated with TR, but also highly heterogeneous TV leaflet structure.

CONCLUSIONS

Moderate or greater TR in patients with hypoplastic left heart syndrome with a Fontan circulation is associated with greater leaflet billow volume, a more laterally directed anterior papillary muscle angle, and greater annular distance between the anteroseptal commissure and anteroposterior commissure. However, there is significant heterogeneity of structure in the TV leaflets in regurgitant valves. Given this variability, an image-informed patient-specific approach to surgical planning may be needed to achieve optimal outcomes in this vulnerable and challenging population.

1454. Describing the Epidemiology of Nosocomial Respiratory Viral Infections (RVIs) at an Academic Medical Center

Background

Nosocomial respiratory viral infections (NRVI), transmitted from infected visitors or healthcare providers to patients, lead to significant morbidity and mortality. This study describes the epidemiology of nosocomial Influenza (flu) and Respiratory Syncytial Virus (RSV) at an academic medical center from 2009 to 2018.

Methods

After institutional review board (IRB) approval, data on NRVI was collected from our Enterprise Data Warehouse and primary chart review. A nosocomial infection was defined as a positive result of flu or RSV collected ≥ 72 hours after admission between April 2009 and March 2018.

Results

There were 93/1,317 (7.1%) nosocomial flu cases and 76/617 (12.3%) nosocomial RSV cases detected during the study period (see Table 1). Flu and RSV were first detected at a median of 6.8 and 8.4 days, respectively, after admission. Patients with nosocomial flu and RSV were more likely to have a cancer diagnosis, be a stem cell transplant recipient within one year, and have undergone chemotherapy in the past 30 days (see Table 2).

Few nosocomial transmissions (15%) occurred outside the usual winter respiratory viral season (December through March, see Figure 1). Table 1Distribution of Nosocomial RVIsTable 2Underlying Medical Conditions Among Patients with Nosocomial and Community-Acquired RVIFigure 1Distribution of nosocomial RVIs over time assessing for transmission seasonality

Conclusion

Nosocomial infections account for 7% of hospitalized flu cases and 12% of hospitalized RSV cases. Infection is more common among patients at high risk of complications. Effort needs to be directed at approaches to reduce the risk of nosocomial transmission of RVI. Future studies are needed to assess the impact of interventions, such as universal masking, on the rate of nosocomial infections.

Disclosures

Michael G. Ison, MD MS, GlaxoSmithKlein: Grant/Research Support|Pulmocide: Grant/Research Support|Viracor Eurfins: Advisor/Consultant.

Statistical shape analysis of the tricuspid valve in hypoplastic left heart sydrome

Hypoplastic left heart syndrome (HLHS) is a congenital heart disease characterized by incomplete development of the left heart. Children with HLHS undergo a series of operations which result in the tricuspid valve (TV) becoming the only functional atrioventricular valve. Some of those patients develop tricuspid regurgitation which is associated with heart failure and death and necessitates further surgical intervention. Repair of the regurgitant TV, and understanding the connections between structure and function of this valve remains extremely challenging. Adult cardiac populations have used 3D echocardiography (3DE) combined with computational modeling to better understand cardiac conditions affecting the TV. However, these structure-function analyses rely on simplistic point-based techniques that do not capture the leaflet surface in detail, nor do they allow robust comparison of shapes across groups. We propose using statistical shape modeling and analysis of the TV using Spherical Harmonic Representation Point Distribution Models (SPHARM-PDM) in order to generate a reproducible representation, which in turn enables high dimensional low sample size statistical analysis techniques such as principal component analysis and distance weighted discrimination. Our initial results suggest that visualization of the differences in regurgitant vs. non-regurgitant valves can precisely locate populational structural differences as well as how an individual regurgitant valve differs from the mean shape of functional valves. We believe that these results will support the creation of modern image-based modeling tools, and ultimately increase the understanding of the relationship between valve structure and function needed to inform and improve surgical planning in HLHS.

Visualization and Quantification of the Unrepaired Complete Atrioventricular Canal Valve Using Open-Source Software

BACKGROUND

Repair of complete atrioventricular canal (CAVC) is often complicated by residual left atrioventricular valve regurgitation. The structure of the mitral and tricuspid valves in biventricular hearts has previously been shown to be associated with valve dysfunction. However, the three-dimensional (3D) structure of the entire unrepaired CAVC valve has not been quantified. Understanding the 3D structure of the CAVC may inform optimized repair.

METHODS

Novel open-source work flows were created in SlicerHeart for the modeling and quantification of CAVC valves on the basis of 3D echocardiographic images. These methods were applied to model the annulus, leaflets, and papillary muscle (PM) structure of 35 patients (29 with trisomy 21) with CAVC using transthoracic 3D echocardiography. The mean leaflet and annular shapes were calculated and visualized using shape analysis. Metrics of the complete native CAVC valve structure were compared with those of normal mitral valves using the Mann-Whitney U test. Associations between CAVC structure and atrioventricular valve regurgitation were analyzed.

RESULTS

CAVC leaflet metrics varied throughout systole. Compared with normal mitral valves, the left CAVC PMs were more acutely angled in relation to the annular plane (P < .001). In addition, the anterolateral PM was laterally and inferiorly rotated in CAVC, while the posteromedial PM was more superiorly and laterally rotated, relative to normal mitral valves (P < .001). Lower native CAVC atrioventricular valve annular height and annular height-to-valve width ratio before repair were both associated with moderate or greater left atrioventricular valve regurgitation after repair (P < .01).

CONCLUSIONS

It is feasible to model and quantify 3D CAVC structure using 3D echocardiographic images. The results demonstrate significant variation in CAVC structure across the cohort and differences in annular, leaflet, and PM structure compared with the mitral valve. These tools may be used in future studies to catalyze future research intended to identify structural associations of valve dysfunction and to optimize repair in this vulnerable and complex population.

Dynamic Annular Modeling of the Unrepaired Complete Atrioventricular Canal Annulus

BACKGROUND

Repair of complete atrioventricular canal (CAVC) is often complicated by atrioventricular valve regurgitation, particularly of the left-sided valve. Understanding the 3-dimensional (3D) structure of the atrioventricular canal annulus before repair may help to inform optimized repair. However, the 3D shape and movement of the CAVC annulus has been neither quantified nor rigorously compared with a normal mitral valve annulus.

METHODS

The complete annuli of 43 patients with CAVC were modeled in 4 cardiac phases using transthoracic 3D echocardiograms and custom code. The annular structure was compared with the annuli of 20 normal pediatric mitral valves using 3D metrics and statistical shape analysis (Procrustes analysis).

RESULTS

The unrepaired CAVC annulus varied in shape significantly throughout the cardiac cycle. Procrustes analysis visually demonstrated that the average normalized CAVC annular shape is more planar than the normal mitral annulus. Quantitatively, the annular height-to-valve width ratio of the native left CAVC atrioventricular valve was significantly lower than that of a normal mitral valve in all systolic phases (P < .001).

CONCLUSIONS

The left half of the CAVC annulus is more planar than that of a normal mitral valve with an annular height-to-valve width ratio similar to dysfunctional mitral valves. Given the known importance of annular shape to mitral valve function, further exploration of the association of 3D structure to valve function in CAVC is warranted.

Skeletal model-based analysis of the tricuspid valve in hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) is a congenital heart disease characterized by incomplete development of the left heart. Children with HLHS undergo a series of operations which result in the tricuspid valve (TV) becoming the only functional atrioventricular valve. Many HLHS patients develop tricuspid regurgitation and right ventricle enlargement which is associated with heart failure and death without surgical intervention on the valve. Understanding the connections between the geometry of the TV and its function remains extremely challenging and hinders TV repair planning. Traditional analysis methods rely on simple anatomical measures which do not capture information about valve geometry in detail. Recently, surface-based shape representations such as SPHARM-PDM have been shown to be useful for tasks such as discriminating between valves with normal or poor function. In this work we propose to use skeletal representations (s-reps), a more feature-rich geometric representation, for modeling the leaflets of the tricuspid valve. We propose an extension to previous s-rep fitting approaches to incorporate application-specific anatomical landmarks and population information to improve correspondence. We use several traditional statistical shape analysis techniques to evaluate the efficiency of this representation: using principal component analysis (PCA) we observe that it takes fewer modes of variation compared to boundary-based approaches to represent 90% of the population variation, while distance-weighted discrimination (DWD) shows that s-reps provide for more significant classification between valves with less regurgitation and those with more. These results show the power of using s-reps for modeling the relationship between structure and function of the tricuspid valve.

Respiratory Syncytial Virus

Human respiratory syncytial virus (RSV) is a negative sense single-stranded RNA virus that can result in epidemics of seasonal respiratory infections. Generally, one of the two genotypes (A and B) predominates in a single season and alternate annually with regional variation. RSV is a known cause of disease and death at both extremes of ages in the pediatric and elderly, as well as immunocompromised populations. The clinical impact of RSV on the hospitalized adults has been recently clarified with the expanded use of multiplex molecular assays. Among adults, RSV can produce a wide range of clinical symptoms due to upper respiratory tract infections potentially leading to severe lower respiratory tract infections, as well as exacerbations of underlying cardiac and lung diseases. While supportive care is the mainstay of therapy, there are currently multiple therapeutic and preventative options under development.

Segmentation of Tricuspid Valve Leaflets From Transthoracic 3D Echocardiograms of Children With Hypoplastic Left Heart Syndrome Using Deep Learning

Hypoplastic left heart syndrome (HLHS) is a severe congenital heart defect in which the right ventricle and associated tricuspid valve (TV) alone support the circulation. TV failure is thus associated with heart failure, and the outcome of TV valve repair are currently poor. 3D echocardiography (3DE) can generate high-quality images of the valve, but segmentation is necessary for precise modeling and quantification. There is currently no robust methodology for rapid TV segmentation, limiting the clinical application of these technologies to this challenging population. We utilized a Fully Convolutional Network (FCN) to segment tricuspid valves from transthoracic 3DE. We trained on 133 3DE image-segmentation pairs and validated on 28 images. We then assessed the effect of varying inputs to the FCN using Mean Boundary Distance (MBD) and Dice Similarity Coefficient (DSC). The FCN with the input of an annular curve achieved a median DSC of 0.86 [IQR: 0.81-0.88] and MBD of 0.35 [0.23-0.4] mm for the merged segmentation and an average DSC of 0.77 [0.73-0.81] and MBD of 0.6 [0.44-0.74] mm for individual TV leaflet segmentation. The addition of commissural landmarks improved individual leaflet segmentation accuracy to an MBD of 0.38 [0.3-0.46] mm. FCN-based segmentation of the tricuspid valve from transthoracic 3DE is feasible and accurate. The addition of an annular curve and commissural landmarks improved the quality of the segmentations with MBD and DSC within the range of human inter-user variability. Fast and accurate FCN-based segmentation of the tricuspid valve in HLHS may enable rapid modeling and quantification, which in the future may inform surgical planning. We are now working to deploy this network for public use.

Invasive aspergillosis in critically ill patients: Review of definitions and diagnostic approaches

Invasive aspergillosis (IA) is an increasingly recognised phenomenon in critically ill patients in the intensive care unit, including in patients with severe influenza and severe coronavirus disease 2019 (COVID-19) infection. To date, there are no consensus criteria on how to define IA in the ICU population, although several criteria are used, including the AspICU criteria and new consensus criteria to categorise COVID-19-associated pulmonary aspergillosis (CAPA). In this review, we describe the epidemiology of IA in critically ill patients, most common definitions used to define IA in this population, and most common clinical specimens obtained for establishing a mycological diagnosis of IA in the critically ill. We also review the most common diagnostic tests used to diagnose IA in this population, and lastly discuss the most common clinical presentation and imaging findings of IA in the critically ill and discuss areas of further needed investigation.

Modeling Tool for Rapid Virtual Planning of the Intracardiac Baffle in Double-Outlet Right Ventricle

PURPOSE

Biventricular repair of double-outlet right ventricle (DORV) necessitates the creation of a complex intracardiac baffle. Creation of the optimal baffle design and placement thereof can be challenging to conceptualize, even with 2-dimensional and 3-dimensional images. This report describes a recently developed methodology for creating virtual baffles to inform intraoperative repair.

DESCRIPTION

A total of 3 heart models of DORV were created from cardiac magnetic resonance images. Baffles were created and visualized using custom software.

EVALUATION

This report demonstrates application of the tool to virtual planning of the baffle for repair of DORV in 3 cases. Models were examined by a multidisciplinary team, on screen and in virtual reality. Baffles could be rapidly created and revised to facilitate planning of the surgical procedure.

CONCLUSIONS

Virtual modeling of the baffle pathway by using cardiac magnetic resonance, creation of physical templates for the baffle, and visualization in virtual reality are feasible and may be beneficial for preoperative planning of complex biventricular repairs in DORV. Further work is needed to demonstrate clinical benefit or improvement in outcomes.

584. Ventricular assist device infections with Pseudomonas aeruginosa

Background

Infection is a leading cause of morbidity and mortality in ventricular assist device (VAD) recipients. Pseudomonas aeruginosa (PA) is the second most common organism implicated in VAD infections, occurring in 10–50% of infections. The epidemiology of VAD recipients with PA infection are poorly described.

Methods

We identified patients (pts) at Northwestern Memorial Hospital with a VAD-specific PA infection from January 1, 2012 to Dec 31, 2019. VADs included the Heartmate II, Heartmate 3, and Heartware HVAD devices. VAD-specific infections were defined according to the 2013 ISHLT Guidelines.

Results

Seventeen out of 91 (18.7%) VAD infections were due to PA. Infections of the driveline exit site (DLES) occurred most commonly (n=15, 88.2%), followed by pocket (n=2, 11.8%) and pump (n=2, 11.8%) infections. Median time to infection after VAD implantation was 295 days (IQR 154 – 440 days). Eight (47.1%) pt isolates were not fluoroquinolone (FQ) susceptible. Resistance to multiple antibiotic classes was observed in pts in whom serial cultures were obtained. Median antibiotic treatment was 107 days (IQR 55 – 183 days, maximum 775 days). Five (29.4%) pts received FQ monotherapy on initial diagnosis, 3 (60%) of whom required change to a different class for resistance. Surgical debridement and VAD exchange were performed in 5 (29.4%) and 3 (17.6%) pts respectively. Co-pathogens were identified in 9 (52.9%) pts, the most common being Staphylococcus aureus (n=2) and Enterococcus spp (n=2). A total of 5 (29.4%) pts went on to successful heart transplantation; one had recurrent PA infection at the prior DLES requiring prolonged antibiotics and removal of retained DL material. All cause 1-year mortality rate was 11.7% (n = 2), both of whom died from cerebrovascular accidents.

Conclusion

VAD-specific infections with PA occurred late after device implantation and required prolonged antibiotic courses. Antimicrobial resistance was high at diagnosis and worsened in pts on prolonged therapy. Morbidity and mortality in pts with PA VAD infections were high. The preponderance of DLES infections warrants further study and highlights the need for improvements in DLES care and infection prevention strategies.

Disclosures

All Authors: No reported disclosures

A clade of SARS-CoV-2 viruses associated with lower viral loads in patient upper airways

BACKGROUND

The rapid spread of SARS-CoV-2, the causative agent of Coronavirus disease 2019 (COVID-19), has been accompanied by the emergence of distinct viral clades, though their clinical significance remains unclear. Here, we aimed to investigate the phylogenetic characteristics of SARS-CoV-2 infections in Chicago, Illinois, and assess their relationship to clinical parameters.

METHODS

We performed whole-genome sequencing of SARS-CoV-2 isolates collected from COVID-19 patients in Chicago in mid-March, 2020. Using these and other publicly available sequences, we performed phylogenetic, phylogeographic, and phylodynamic analyses. Patient data was assessed for correlations between demographic or clinical characteristics and virologic features.

FINDINGS

The 88 SARS-CoV-2 genome sequences in our study separated into three distinct phylogenetic clades. Clades 1 and 3 were most closely related to viral sequences from New York and Washington state, respectively, with relatively broad distributions across the US. Clade 2 was primarily found in the Chicago area with limited distribution elsewhere. At the time of diagnosis, patients infected with Clade 1 viruses had significantly higher average viral loads in their upper airways relative to patients infected with Clade 2 viruses, independent of disease severity.

INTERPRETATION

These results show that multiple variants of SARS-CoV-2 were circulating in the Chicago area in mid-March 2020 that differed in their relative viral loads in patient upper airways. These data suggest that differences in virus genotype can impact viral load and may influence viral spread.

FUNDING

Dixon Family Translational Research Award, Northwestern University Clinical and Translational Sciences Institute (NUCATS), National Institute of Allergy and Infectious Diseases (NIAID), Lurie Comprehensive Cancer Center, Northwestern University Emerging and Re-emerging Pathogens Program.

Successful integration of a three-dimensional transthoracic echocardiography-derived model with an electroanatomic mapping system to guide catheter ablation of WPW

Three-dimensional transthoracic echocardiography (3DE)-derived heart models have not previously been utilized to guide catheter ablation. In this case report, we describe the creation of a 3DE model from transthoracic echocardiography, import of the model into CARTO3, and successful use of the model as a guide during mapping and ablation of a right lateral accessory pathway. We believe this technique represents a valuable alternative to the integration of computed tomography or magnetic resonance imaging-derived anatomic data, and that it has the potential to improve the definition of the atrioventricular valve annuli during catheter ablation of accessory pathways.

A Unique Clade of SARS-CoV-2 Viruses is Associated with Lower Viral Loads in Patient Upper Airways

BACKGROUND

The rapid spread of SARS-CoV-2, the causative agent of Coronavirus disease 2019 (COVID-19), has been accompanied by the emergence of distinct viral clades, though their clinical significance remains unclear. Here, we aimed to investigate the phylogenetic characteristics of SARS-CoV-2 infections in Chicago, Illinois and assess their relationship to clinical parameters.

METHODS

We performed whole-genome sequencing of SARS-CoV-2 isolates collected from COVID-19 patients in a Chicago healthcare system in mid-March, 2020. Using these and other publicly available sequences, we performed phylogenetic, phylogeographic, and phylodynamic analyses. Patient data was assessed for correlations between demographic or clinical characteristics and virologic features.

FINDINGS

The 88 SARS-CoV-2 genome sequences in our study separated into three distinct phylogenetic clades. Clade 1 was most closely related to viral sequences from New York, and showed evidence of rapid expansion across the US, while Clade 3 was most closely related to those in Washington state. Clade 2 was localized primarily to the Chicago area with limited evidence of expansion elsewhere. At the time of diagnosis, patients infected with Clade 1 viruses had significantly higher average viral loads in their upper airways relative to patients infected with Clade 2 viruses, independent of time to symptom onset and disease severity.

INTERPRETATION

These results show that multiple variants of SARS-CoV-2 are circulating in the Chicago area that differ in their relative viral loads in patient upper airways. These data suggest that differences in virus genotype impact viral load and may in turn influence viral transmission and spread.

FUNDING

Dixon Family Translational Research Award, Northwestern University Clinical and Translational Sciences Institute (NUCATS), National Institute of Allergy and Infectious Diseases (NIAID).

Three-Dimensional Modeling of Surgically Implanted Stent-Based Valves in the Mitral Position in Children

PURPOSE

In children with a mitral annulus too small to accommodate traditional prostheses, surgical implantation of stent-based valves is a promising option. However no reliable preoperative methods exist to guide patient selection, device sizing, and positioning. We describe a novel methodology to visualize and quantify device fit in 3-dimensional echocardiogram (3DE)-derived heart models.

DESCRIPTION

Heart models were created from existing preoperative 3DEs using custom software. Valve models were virtually implanted into the models, and both device fit and left ventricular outflow tract (LVOT) area were quantified.

EVALUATION

The 3DEs of 3 patients who underwent Melody valve placement in the mitral position were retrospectively modeled: 1 with LVOT obstruction, 1 with perivalvar leak, and 1 without complications. In all cases 2-dimensional measurements underestimated 3D annular dimensions, and the patient with clinical LVOT obstruction had the lowest predicted LVOT area-to-aortic area ratio (0.5).

CONCLUSIONS

3DE-based preoperative modeling of surgical implantation of stent-based valves in the mitral position may improve quantification of mitral valve dimensions and inform risk stratification for potential LVOT obstruction.

Respiratory syncytial virus infection in adults

Human respiratory syncytial virus (RSV) belongs to the recently defined Pneumoviridae family, Orthopneumovirus genus. It is a negative sense, single stranded RNA virus that results in epidemics of respiratory infections that typically peak in the winter in temperate climates and during the rainy season in tropical climates. Generally, one of the two genotypes (A and B) predominates in a single season, alternating annually, although regional variation occurs. RSV is a cause of disease and death in children, older people, and immunocompromised patients, and its clinical effect on adults admitted to hospital is clarified with expanded use of multiplex molecular assays. Among adults, RSV produces a wide range of clinical symptoms including upper respiratory tract infections, severe lower respiratory tract infections, and exacerbations of underlying disease. Here we discuss the latest evidence on the burden of RSV related disease in adults, especially in those with immunocompromise or other comorbidities. We review current therapeutic and prevention options, as well as those in development.

Community-acquired respiratory viruses in solid organ transplant

PURPOSE OF REVIEW

Respiratory viruses are common in solid organ transplant (SOT) recipients and recognized as a significant cause of mortality and morbidity. This review examines the literature on influenza and noninfluenza viruses in the SOT recipient.

RECENT FINDINGS

Advances in immunosuppression and antimicrobial prophylaxis have led to improved patient and graft survival, yet respiratory viruses continue to be a common cause of disease in this population. Influenza viruses have received top priority regarding prevention and treatment, whereas advances in molecular diagnostic tests detecting an array of other respiratory viruses have expanded our knowledge about the epidemiology and impact of these viruses in both the general population and SOT patients. Effective treatment and prevention for noninfluenza respiratory viruses are only emerging.

SUMMARY

Respiratory viruses can contribute to a wide array of symptoms in SOT, particularly in lung transplant recipients. The clinical manifestations, diagnosis, and treatment options for influenza and noninfluenza viruses in SOT patients are reviewed. PCR and related molecular techniques represent the most sensitive diagnostic modalities for detection of respiratory viruses. Early therapy is associated with improved outcomes. Newer classes of antivirals and antibodies are under continuous development for many of these community acquired respiratory viruses.

Advances in respiratory virus therapeutics - A meeting report from the 6th isirv Antiviral Group conference

The International Society for Influenza and other Respiratory Virus Diseases held its 6th Antiviral Group (isirv-AVG) conference in Rockville, Maryland, November 13-15, 2018. The three-day program was focused on therapeutics towards seasonal and pandemic influenza, respiratory syncytial virus, coronaviruses including MERS-CoV and SARS-CoV, human rhinovirus, and other respiratory viruses. Updates were presented on several influenza antivirals including baloxavir, CC-42344, VIS410, immunoglobulin, immune plasma, MHAA4549A, pimodivir (JNJ-63623872), umifenovir, and HA minibinders; RSV antivirals including presatovir (GS-5806), ziresovir (AK0529), lumicitabine (ALS-008176), JNJ-53718678, JNJ-64417184, and EDP-938; broad spectrum antivirals such as favipiravir, VH244, remdesivir, and EIDD-1931/EIDD-2801; and host directed strategies including nitazoxanide, eritoran, and diltiazem. Other topics included considerations of novel endpoints such as ordinal scales and patient reported outcomes (PRO), and study design issues, and other regulatory considerations for antiviral drug development. The aim of this report is to provide a summary of the presentations given at this meeting.

Toward predictive modeling of catheter-based pulmonary valve replacement into native right ventricular outflow tracts

BACKGROUND

Pulmonary insufficiency is a consequence of transannular patch repair in Tetralogy of Fallot (ToF) leading to late morbidity and mortality. Transcatheter native outflow tract pulmonary valve replacement has become a reality. However, predicting a secure, atraumatic implantation of a catheter-based device remains a significant challenge due to the complex and dynamic nature of the right ventricular outflow tract (RVOT). We sought to quantify the differences in compression and volume for actual implants, and those predicted by pre-implant modeling.

METHODS

We used custom software to interactively place virtual transcatheter pulmonary valves (TPVs) into RVOT models created from pre-implant and post Harmony valve implant CT scans of 5 ovine surgical models of TOF to quantify and visualize device volume and compression.

RESULTS

Virtual device placement visually mimicked actual device placement and allowed for quantification of device volume and radius. On average, simulated proximal and distal device volumes and compression did not vary statistically throughout the cardiac cycle (P = 0.11) but assessment was limited by small sample size. In comparison to actual implants, there was no significant pairwise difference in the proximal third of the device (P > 0.80), but the simulated distal device volume was significantly underestimated relative to actual device implant volume (P = 0.06).

CONCLUSIONS

This study demonstrates that pre-implant modeling which assumes a rigid vessel wall may not accurately predict the degree of distal RVOT expansion following actual device placement. We suggest the potential for virtual modeling of TPVR to be a useful adjunct to procedural planning, but further development is needed.

Multiple genes elucidate the evolution of venomous snail-hunting Conus species

The species-rich Cone snails (Conus sp.) are predatory, marine gastropods known for small venom peptides that are valuable for pharmacological research applications. Phylogenetic analyses with mitochondrial rRNA sequences have facilitated peptide discovery. However, these relatively conserved genes leave unresolved the closer relationships among many species. We sequenced 26 internal transcribed spacer 2 (ITS2) sequences from genomic ribosomal DNA to elucidate the evolutionary relationships among molluscivorous species and to piscivorous and vermivorous species. We show that ITS2 sequences are well conserved within species but are sufficiently variable among species to resolve recent divergences. Using Bayesian, maximum likelihood and log-determinant methods, we use the ITS sequences to resolve portions of the tree that could not be resolved using the more conventional mt rRNA sequences. When the ITS2 sequences are added to existing COI and to the more conserved rRNA sequences and then properly modeled, support throughout the tree is increased. This enables us to show finer relationships among the molluscivorous species that reveal three well-supported clades (Conus, Cylinder, and Darioconus) and renders the ITS2 sequences an essential component in advancing the discovery and pharmacological characterization of novel peptides from the venoms of these molluscs.