Percent Thrombus Predicts Popliteal Artery Aneurysm Related Limb Threatening Events

OBJECTIVE

The objective of this study was to identify clinical and anatomic characteristics of Popliteal artery aneurysms (PAAs) associated with acutely limb threatening events.

SUMMARY BACKGROUND DATA

Popliteal artery aneurysms (PAAs) are associated with high morbidity and mortality. Current guidelines recommend operative repair for PAAs with a diameter greater than 20 mm based on very limited evidence.

METHODS

This retrospective cross-sectional cohort was derived from a multi-institutional database queried for all patients with a PAA from 2008 to 2022. Duplex ultrasound (DUS) characteristics of PAAs were abstracted by registered physicians in vascular interpretation. Symptom status at the time of DUS was divided into three categories: asymptomatic PAA, symptomatic PAA with claudication or chronic limb ischemia, and acutely limb threatening PAAs with a thromboembolic event, acute limb ischemia, or rupture.

RESULTS

There were 470 PAAs identified in 331 patients. The mean age was 74 years at diagnosis, 94% of patients were white, and 97% of patients were male. In a univariate analysis, patient comorbidities and medications were not associated with symptom status. In a multivariate analysis including age, higher percent thrombus was significantly associated with symptomatic PAAs (RRR 15.2; CI 2.69-72.3; P<0.01) and PAAs with an acutely limb threatening event (RRR 17.9; CI 3.76-85.0; P<0.01). All other anatomic characteristics were not associated with symptom status.

CONCLUSION

Percent thrombus was significantly associated with symptomatic PAAs and acutely limb threatening events, whereas diameter was not significantly associated with any symptom group. This analysis supports the use of percent thrombus in identifying high risk PAAs that warrant repair.

Local Anesthesia for Endovascular Repair of Abdominal Aortic Aneurysm Allows for Accurate Graft Deployment with Durable Results

BACKGROUND

Local anesthesia (LA) is sparsely used in endovascular aneurysm repair (EVAR) despite short-term benefit, likely secondary to concerns over patient movement preventing accurate endograft deployment. The objective of this study is to examine the association between anesthesia type and endoleak, sac regression, reintervention, and mortality.

METHODS

The Vascular Quality Initiative database was queried for all EVAR cases from 2014 to 2022. Patients were included if they underwent percutaneous elective EVAR with anatomical criteria within instructions for use of commercially approved endografts. Multivariable logistic regression with propensity score weighting was used to determine the association between anesthesia type on the risk of any endoleak noted by intraoperative completion angiogram and sac regression. Multivariable survival analysis with propensity score weighting was used to determine the association between anesthesia type and endoleak at 1 year, long-term reintervention, and mortality.

RESULTS

Thirteen thousand nine hundred thirty two EVARs met inclusion criteria: 1,075 (8%) LA and 12,857 (92%) general anesthesia (GA). On completion angiogram, LA was associated with fewer rates of any endoleaks overall (16% vs. 24%, P < 0.001). On multivariable analysis with propensity score weighting, LA was associated with similar adjusted odds of any endoleak on intraoperative completion angiogram (odds ratio [OR] 0.56, 95% confidence interval [CI] 0.47-0.68) as well as combined type 1a and type 1b endoleaks (OR 0.72, 95% CI 0.47-1.09). Follow-up computed tomography imaging at 1 year was available for 4,892 patients, 377 (8%) LA and 4,515 (92%) GA. At 1 year, LA was associated with similar rate of freedom from any endoleaks compared to GA (0.66 [95% CI 0.63-0.69] vs. 0.71 [95% CI 0.70-0.72], P = 0.663) and increased rates of sac regression (50% vs. 45%, P = 0.040). On multivariable analysis with propensity score weighting, LA and GA were associated with similar adjusted odds of sac regression (OR 1.22, 95% CI 0.97-1.55). LA and GA had similar rates of endoleak at 1 year (hazard ratio [HR] 0.14, 95% CI 0.63-1.07); however, LA was associated with decreased hazards of combined type 1a and 1b endoleaks at 1 year (HR 0.87, 95% CI 0.80-0.96). LA and GA had similar adjusted long-term reintervention rate (HR 0.77, 95% CI 0.44-1.38) and long-term mortality (HR 1.100, 95% CI 079-1.25).

CONCLUSIONS

LA is not associated with increased adjusted rates of any endoleak on completion angiogram or at 1-year follow-up compared to GA. LA is associated with decreased adjusted rates of type 1a and type 1b endoleak at 1 year, but similar rates of sac regression, long-term reintervention, and mortality. Concerns for accurate graft deployment should not preclude use of LA and LA should be increasingly considered when deciding on anesthetic type for standard elective EVAR.

Popliteal artery aneurysm ultrasound criteria for reporting characteristics

INTRODUCTION

Duplex ultrasound (DUS) is the modality of choice for surveillance of popliteal artery aneurysms (PAAs). However, noninvasive vascular laboratories have no standard guidelines for reporting results. This study assessed reports of PAA DUS for inclusion of information pertinent to operative decision-making and timing of surveillance.

METHODS

This study was a retrospective review of a multi-institutional repository that was queried for all patients with a PAA from 2008 to 2022 and confirmed via manual chart review. DUS reports were abstracted and images were individually annotated for features of interest including dimensions, flow abnormalities, and percent thrombus burden.

RESULTS

A total of 166 PAAs in 130 patients had at least one DUS available for viewing. Postoperative surveillance of PAAs was performed at several intervals: the first at 30 months (IQR 3.7-113, n = 44), the second at 64 months (IQR 20-172, n = 31), and the third at 152 months (IQR 46-217, n = 16) after the operation. The largest diameter of operative PAAs (median 27.5 mm, IQR 21.8-38.0) was significantly greater than nonoperative PAAs (median 20.9 mm, IQR 16.7-27.3); p < 0.01. Fewer than 33 (21%) reports commented on patency of distal runoff. We calculated an average percent thrombus of 60% (IQR 19-81) in nonoperative PAAs, which is significantly smaller than 75% (IQR 58-89) in operative PAAs; p < 0.01.

CONCLUSION

In this multi-institutional retrospective study, PAAs are often not followed at intervals recommended by the Society for Vascular Surgery guidelines and do not include all measurements necessary for clinical decision-making in the multi-institutional repository studied. There should be standardization of PAA DUS protocols performed by all noninvasive vascular laboratories to ensure completeness of PAA DUS images and inclusion of characteristics pertinent to clinical decision-making in radiology reports.

Feasibility of Encord Artificial Intelligence Annotation of Arterial Duplex Ultrasound Images

DUS measurements for popliteal artery aneurysms (PAAs) specifically can be time-consuming, error-prone, and operator-dependent. To eliminate this subjectivity and provide efficient segmentation, we applied artificial intelligence (AI) to accurately delineate inner and outer lumen on DUS. DUS images were selected from a cohort of patients with PAAs from a multi-institutional platform. Encord is an easy-to-use, readily available online AI platform that was used to segment both the inner lumen and outer lumen of the PAA on DUS images. A model trained on 20 images and tested on 80 images had a mean Average Precision of 0.85 for the outer polygon and 0.23 for the inner polygon. The outer polygon had a higher recall score than precision score at 0.90 and 0.85, respectively. The inner polygon had a score of 0.25 for both precision and recall. The outer polygon false-negative rate was the lowest in images with the least amount of blur. This study demonstrates the feasibility of using the widely available Encord AI platform to identify standard features of PAAs that are critical for operative decision making.

Outcomes of symptomatic penetrating aortic ulcer and intramural hematoma in the endovascular era

BACKGROUND

Although endovascular technology has resulted in a paradigm shift in treatment, medical management remains the standard of care for penetrating aortic ulcer (PAU) and intramural hematoma (IMH). This study aimed to detail the short- and long-term outcomes of symptomatic PAU/IMH.

METHODS

Institutional data on symptomatic PAU/IMH were gathered (2005-2020). The primary outcome was the composite of recurrent symptoms, radiographic progression, intervention, rupture, and death from related or unknown cause. Factors associated with the primary outcome were determined using a Fine-Gray model with death from an unrelated cause as a competing risk.

RESULTS

A total of 83 symptomatic patients treated with medical management aside from ruptures and type A dissections: 21 isolated PAU, 30 isolated IMH, and 32 IMH and PAU. Adverse outcomes included symptom recurrence in 14 (16.9%), radiographic progression to dissection or saccular aneurysm in 17 (20.5%), surgery in 20 (24.1%) (17 thoracic endovascular aortic repair, 1 endovascular aortic repair, 1 frozen elephant trunk, and 1 open repair), and rupture in 4 (4.8%). Twenty-seven patients (32.5%) died during follow-up: 6 from IMH treatment complications, 8 from an unknown cause, and 13 from other causes. The 30-day, 1-year, and 5-year cumulative incidences of the primary outcome was 26.5% (95% confidence interval [CI], 16.9%-37.0%), 44.9% (95% CI, 32.8%-56.2%), and 57.5% (95% CI, 42.4%-69.9%), respectively. IMH with PAU was associated with a significantly higher risk of the primary outcome compared with isolated IMH (subdistribution hazard ratio, 2.21; 95% CI, 1.09-4.50; P = .027) and isolated PAU (subdistribution hazard ratio, 3.58; 95% CI, 1.44-8.88; P = .006).

CONCLUSIONS

Complications from symptomatic PAU and IMH are frequent, with intervention, recurrent symptoms, radiographic progression, rupture, or death affecting 25% of patients at 30 days after diagnosis and almost one-half of patients 1 year after diagnosis. Given the high rate of adverse events in this population, investigation into a more aggressive interventional strategy may warranted, especially in patients with a combined IMH and PAU.

Increased anti-thrombotic therapy is associated with decreased major adverse limb events in patients with low wound and foot infection scores

INTRODUCTION

The optimal anti-thrombotic management of patients after lower extremity bypass has yet to be fully elucidated, in part due to significant heterogeneity in patient presentation and practice patterns. The Wound, Ischemia, and foot Infection (WIfI) score is a validated scoring system to assist in the management of patients with chronic limb threatening ischemia (CLTI). We hypothesized that performing a restriction analysis based on WIFI scores would assist in the postoperative anti-thrombotic management of patients undergoing infrainguinal bypass.

METHODS

A retrospective cohort of infrainguinal bypass procedures completed at a single hospital system between January 2018 and January 2021 was selected, and preoperative WIfI scores were extracted for each patient. Patients with either Wound scores of 2 and 3, or Ischemia Scores of 0 and 1, or Foot Infection Scores of 3 were excluded. Based on the type of anti-thrombotic regimen on discharge, demographics, comorbidities, type of bypass, 30-day rates of graft occlusion, major amputation, mortality, and major adverse limb events (MALE) were analyzed. Statistical analysis included t-tests, chi square tests, and time-to-event survival analysis.

RESULTS

230 procedures were included in the study. 69 (30.0%) patients were discharged on single antiplatelet therapy (SAPT), compared to 161 (70.0%) who were discharged on either dual antiplatelet therapy or anticoagulation (DAPT/AC). There was a higher prevalence of bypasses using prosthetic conduit in the DAPT/AC group (45.9 vs 31.8%, p = .047); no other demographic or procedural variable analyzed had any significant differences. At 30-days postoperatively, there was no significant difference in postoperative reintervention rates, however, the DAPT/AC group had significantly lower rates of mortality (1.2 vs 7.2%, p = .01), major amputation (1.2% vs 5.8%, p = .04), and MALE (3.7 vs 13.0%, p < .01). There were no significant differences in bleeding complications. Survival analysis demonstrated that MALE-free survival was higher in the DAPT/AC group compared to the SAPT group (p < .01). On Cox regression analysis, DAPT/AC was associated with significantly decreased rates of MALE + mortality (Hazard Ratio (HR) 0.20 [0.06 - 0.66]).

CONCLUSION

Lower extremity bypasses patients with low Wound and low foot Infection scores who are discharged on DAPT/AC postoperatively have a significantly higher 30-day MALE-free survival rate compared to patients discharged on SAPT; consideration could be made to preferentially discharge such post-bypass patients on DAPT/AC.

Analysis of Female Participant Representation in Registered Oncology Clinical Trials in the United States from 2008 to 2020

BACKGROUND

Female underrepresentation in oncology clinical trials can result in outcome disparities. We evaluated female participant representation in US oncology trials by intervention type, cancer site, and funding.

MATERIALS AND METHODS

Data were extracted from the publicly available Aggregate Analysis of ClinicalTrials.gov database. Initially, 270,172 studies were identified. Following the exclusion of trials using Medical Subject Heading terms, manual review, those with incomplete status, non-US location, sex-specific organ cancers, or lacking participant sex data, 1650 trials consisting of 240,776 participants remained. The primary outcome was participation to prevalence ratio (PPR): percent females among trial participants divided by percent females in the disease population per US Surveillance, Epidemiology, and End Results Program data. PPRs of 0.8-1.2 reflect proportional female representation.

RESULTS

Females represented 46.9% of participants (95% CI, 45.4-48.4); mean PPR for all trials was 0.912. Females were underrepresented in surgical (PPR 0.74) and other invasive (PPR 0.69) oncology trials. Among cancer sites, females were underrepresented in bladder (odds ratio [OR] 0.48, 95% CI 0.26-0.91, P = .02), head/neck (OR 0.44, 95% CI 0.29-0.68, P < .01), stomach (OR 0.40, 95% CI 0.23-0.70, P < .01), and esophageal (OR 0.40 95% CI 0.22-0.74, P < .01) trials. Hematologic (OR 1.78, 95% CI 1.09-1.82, P < .01) and pancreatic (OR 2.18, 95% CI 1.46-3.26, P < .01) trials had higher odds of proportional female representation. Industry-funded trials had greater odds of proportional female representation (OR 1.41, 95% CI 1.09-1.82, P = .01) than US government and academic-funded trials.

CONCLUSIONS

Stakeholders should look to hematologic, pancreatic, and industry-funded cancer trials as exemplars of female participant representation and consider female representation when interpreting trial results.

Wall shear rate and energy loss coefficient measures using conventional Doppler ultrasound do not predict carotid plaque progression

Background: The rate of carotid plaque progression is believed to be related to blood flow hemodynamics and shear stress. Our objective was to determine if wall shear rate (WSR) and the energy loss coefficient (ELC) measured by Doppler ultrasound could predict atherosclerotic carotid disease progression. Patients and methods: Patients at a large tertiary center with an initial ultrasound between 2016 and 2018 with a significant carotid plaque were included if they had at least one 6 months follow-up comparative study. Stenosis progression was assessed according to the NASCET (The North American Symptomatic Carotid Endarterectomy Trial) percentage criterion. Results: The average annual progression rate for the 74 plaques included was 5.7% NASCET per year. We identified 18 plaques with ≥10% NASCET progression and 56 plaques without significant progression <10% NASCET. Among the plaques with progression, only four plaques had progression greater than 20% NASCET. Median WSR was 6266 s^-1 [5813-8974] in plaques with progression and 6564 s^-1 [5285-8766] in stable plaques (p=0.643). Median ELC was 3.86 m² [2.78-5.53] in plaque with progression and 4.32 m² [3.42-6.81] in stable plaques (p=0.296). Conclusions: Although it is a widely accepted hypothesis that shear stress and hemodynamics of the carotid bifurcation contribute to plaque progression, we found that WSR and ELC estimated by Doppler ultrasound do not reliably predict atherosclerotic plaque progression in the carotid artery. Other ultrasound modalities, such as 3D imaging, may be used to assess the influence of plaque geometry and hemodynamics in plaque progression.

Routine Completion Angiography For Infrainguinal Bypasses Using Prosthetic Conduit: No Effect On Postoperative Patency

INTRODUCTION

Recent studies have demonstrated increased postoperative patency with the use of routine completion angiography for bypass using venous conduit. Compared to vein conduits however, prosthetic conduits are less plagued by technical issues such as unlysed valves or arteriovenous fistulae. The effect of routine completion angiography on bypass patency in prosthetic bypasses has yet to be compared to the more traditional selective use of completion imaging.

METHODS

A retrospective review of all infrainguinal bypass procedures using prosthetic conduit completed at a single hospital system from 2001 to 2018 was performed. Demographics, comorbidities, intraoperative reintervention rates and 30-day rates of graft thrombosis were analyzed. Statistical analysis included t-tests, chi square tests and cox regression.

RESULTS

Four hundred and ninety-eight bypasses that were performed in 426 patients met inclusion criteria. Fifty-six (11.2%) bypasses were classified into the routine completion angiogram group compared to 442 (88.8%) into the no completion angiogram group. Patients who underwent routine completion angiograms had a rate of intraoperative reintervention of 21.4%. When comparing bypasses that underwent routine completion angiography versus no completion angiography, there were no significant differences in rates of reintervention (3.5% vs. 4.5%, P=0.74) or graft occlusion (3.5% vs. 4.7%, P=0.69) at 30-days postoperatively.

CONCLUSION

Almost one-quarter of lower extremity bypasses using prosthetic conduit that undergo routine completion angiography undergo post-angiogram bypass revision, however this is not associated with an increased graft patency at 30-days postoperatively.

Understanding motivations behind medical student involvement in COVID-19 pandemic relief efforts

BACKGROUND

Although students were removed from patient-facing settings at the beginning of the COVID-19 pandemic due to concerns of burdening teaching physicians and depleting personal protective equipment, some leaders suggest students can be effectively utilized when personnel resources may be scarce. There have been narrative discussions surrounding medical student involvement, but no studies exploring the attitudes of these students. The authors aim to quantify the degree to which factors influenced a medical student's decision to or to not volunteer during the pandemic and to characterize medical students' attitudes towards medical professionals' duty to serve in a pandemic.

METHODS

The authors developed and tested a secure web-based survey before distribution to students at 23 different US allopathic medical schools that did not graduate medical students early to aid in pandemic efforts between April and June 2020. Of the 599 students who completed the survey, 65.5% self-identified as female and were on average 25.94 years old (SD = 2.5). Multiple comparisons were made based on volunteer status. Ordinal scale questions were compared with the Mann Whitney U test, and the Chi-Squared test was used for categorical variables using R version 3.62.

RESULTS

67.6% of students volunteered in pandemic relief activities and a majority of those students volunteered in non-patient-facing roles. Community service, new skills, and time commitment were top 3 influencing factors for students who volunteered, while risk to other, time commitment, and risk to self were top 3 influencing factors for students who chose not to volunteer. Compared to other specialties, students interested in primary care specialties agreed to a greater degree that physicians have a duty to serve in pandemic relief efforts.

CONCLUSIONS

Medical students who volunteered cited self-serving factors and altruistic values as significant motivators. Students who did not volunteer were significantly more concerned with risks of COVID-19 exposure. However, medical students in general agreed that students should be allowed to volunteer in COVID-19 related relief efforts. As large areas of the United States continue to experience increases in COVID-19 cases, institutions should involve medical students in balancing the level of acceptable risk with the educational benefits.

Genome-wide association and multi-trait analyses characterize the common genetic architecture of heart failure

Heart failure is a leading cause of cardiovascular morbidity and mortality. However, the contribution of common genetic variation to heart failure risk has not been fully elucidated, particularly in comparison to other common cardiometabolic traits. We report a multi-ancestry genome-wide association study meta-analysis of all-cause heart failure including up to 115,150 cases and 1,550,331 controls of diverse genetic ancestry, identifying 47 risk loci. We also perform multivariate genome-wide association studies that integrate heart failure with related cardiac magnetic resonance imaging endophenotypes, identifying 61 risk loci. Gene-prioritization analyses including colocalization and transcriptome-wide association studies identify known and previously unreported candidate cardiomyopathy genes and cellular processes, which we validate in gene-expression profiling of failing and healthy human hearts. Colocalization, gene expression profiling, and Mendelian randomization provide convergent evidence for the roles of BCKDHA and circulating branch-chain amino acids in heart failure and cardiac structure. Finally, proteome-wide Mendelian randomization identifies 9 circulating proteins associated with heart failure or quantitative imaging traits. These analyses highlight similarities and differences among heart failure and associated cardiovascular imaging endophenotypes, implicate common genetic variation in the pathogenesis of heart failure, and identify circulating proteins that may represent cardiomyopathy treatment targets.

Metabolite patterns associated with individual response to supervised exercise therapy in patients with intermittent claudication

Objective

Supervised exercise therapy (SET) is the first line treatment for intermittent claudication owing to peripheral arterial disease. Despite multiple randomized controlled trials proving the efficacy of SET, there are large differences in individual patient's responses. We used plasma metabolomics to identify potential metabolic influences on the individual response to SET.

Methods

Primary metabolites, complex lipids, and lipid mediators were measured on plasma samples taken at before and after Gardner graded treadmill walking tests that were administered before and after 12 weeks of SET. We used an ensemble modeling approach to identify metabolites or changes in metabolites at specific time points that associated with interindividual variability in the functional response to SET. Specific time points analyzed included baseline metabolite levels before SET, dynamic metabolomics changes before SET, the difference in pre- and post-SET baseline metabolomics, and the difference (pre- and post-SET) of the dynamic (pre- and post-treadmill).

Results

High levels of baseline anandamide levels pre- and post-SET were associated with a worse response to SET. Increased arachidonic acid (AA) and decreased levels of the AA precursor dihomo-γ-linolenic acid across SET were associated with a worse response to SET. Participants who were able to tolerate large increases in AA during acute exercise had longer, or better, walking times both before and after SET.

Conclusions

We identified two pathways of relevance to individual response to SET that warrant further study: anandamide synthesis may activate endocannabinoid receptors, resulting in worse treadmill test performance. SET may train patients to withstand higher levels of AA, and inflammatory signaling, resulting in longer walking times.

Clinical Relevance

This manuscript describes the use of metabolomic techniques to measure the interindividual effects of SET in patients with peripheral artery disease (PAD). We identified high levels of AEA are linked to CB1 signaling and activation of inflammatory pathways. This alters energy expenditure in myoblasts by decreasing glucose uptake and may induce an acquired skeletal muscle myopathy. SET may also help participants tolerate increased levels of AA and inflammation produced during exercise, resulting in longer walking times. This data will enhance understanding of the pathophysiology of PAD and the mechanism by which SET improves walking intolerance.

Development of a GalNAc-Tyrosine-Specific Monoclonal Antibody and Detection of Tyrosine O-GalNAcylation in Numerous Human Tissues and Cell Lines

Glycosylation is a vital post-translational modification involved in a range of biological processes including protein folding, signaling, and cell-cell interactions. In 2011, a new type of O-linked glycosylation was discovered, wherein the side-chain oxygen of tyrosine is modified with a GalNAc residue (GalNAc-Tyr). At present, very little is known about GalNAc-Tyr prevalence, function, or biosynthesis. Herein, we describe the design and synthesis of a GalNAc-Tyr-derived hapten and its use in generating a GalNAc-Tyr selective monoclonal antibody. The antibody, G10C, has an unusually high affinity (app KD = 100 pM) and excellent selectivity for GalNAc-Tyr. We also obtained a crystal structure of the G10C Fab region in complex with 4-nitrophenyl-N-acetyl-α-d-galactosaminide (a small molecule mimic of GalNAc-Tyr) providing insights into the structural basis for high affinity and selectivity. Using this antibody, we discovered that GalNAc-Tyr is widely expressed in most human tissues, indicating that it is a ubiquitous and underappreciated post-translational modification. Localization to specific cell types and organ substructures within those tissues indicates that GalNAc-Tyr is likely regulated in a cell-specific manner. GalNAc-Tyr was also observed in a variety of cell lines and primary cells but was only present on the external cell surface in certain cancer cell lines, suggesting that GalNAc-Tyr localization may be altered in cancer cells. Collectively, the results shed new light on this under-studied form of glycosylation and provide access to new tools that will enable expanded biochemical and clinical investigations.

Identifying Strategies for Struggling Surgery Residents

BACKGROUND

Struggling residents are not uncommon in general surgery. Early identification of these residents and effective remediation remain imperfect.

MATERIALS AND METHODS

We performed a survey of program directors (PD) across all general surgery residencies. Survey questions included the following: demographic information about the program and PD, 10 vignettes about hypothetical residents struggling in various ACGME milestones to assess how PDs would address these deficiencies, and self-reported PD preparedness and availability of resources to support struggling residents.

RESULTS

In total, we received 82 responses to our survey. All PDs who participated in our study reported having struggling residents in their program. The three most common ways struggling residents are identified were faculty word-of-mouth, formal evaluations such as milestones and ABSITE performance, and resident word-of-mouth. Over 18% of PDs reported having little to no relevant training in addressing the needs of a struggling resident, and 65.9% of PDs did not feel that their program had 'completely adequate' resources to address these needs. In the majority of cases, PDs offer mentorship with themselves or other faculty as a remediation strategy with infrequent use of other resources.

CONCLUSIONS

Strategies to identify struggling residents and remediation strategies varied widely across programs. Diversifying remediation approaches should be considered for more effective remediation.

Multi-Trait Genome-Wide Association Study of Atherosclerosis Detects Novel Pleiotropic Loci

Although affecting different arterial territories, the related atherosclerotic vascular diseases coronary artery disease (CAD) and peripheral artery disease (PAD) share similar risk factors and have shared pathobiology. To identify novel pleiotropic loci associated with atherosclerosis, we performed a joint analysis of their shared genetic architecture, along with that of common risk factors. Using summary statistics from genome-wide association studies of nine known atherosclerotic (CAD, PAD) and atherosclerosis risk factors (body mass index, smoking initiation, type 2 diabetes, low density lipoprotein, high density lipoprotein, total cholesterol, and triglycerides), we perform 15 separate multi-trait genetic association scans which resulted in 25 novel pleiotropic loci not yet reported as genome-wide significant for their respective traits. Colocalization with single-tissue eQTLs identified candidate causal genes at 14 of the detected signals. Notably, the signal between PAD and LDL-C at the PCSK6 locus affects PCSK6 splicing in human liver tissue and induced pluripotent derived hepatocyte-like cells. These results show that joint analysis of related atherosclerotic disease traits and their risk factors allowed identification of unified biology that may offer the opportunity for therapeutic manipulation. The signal at PCSK6 represent possible shared causal biology where existing inhibitors may be able to be leveraged for novel therapies.

A Systematic Review of Thromboelastography Utilization in Vascular and Endovascular Surgery

OBJECTIVE

Thromboelastography (TEG) is diagnostic modality that analyzes real-time blood coagulation parameters. Clinically, TEG primarily allows for directed blood component resuscitation among patients with acute blood loss and coagulopathy. The utilization of TEG has been widely adopted in among other surgical specialties; however, its use in vascular surgery is less prominent. We aimed to provide an up-to-date review of TEG utilization in vascular and endovascular surgery.

METHODS

Using PRISMA guidelines, a literature review with the Medical Subject Headings (MeSH) terms "TEG and arterial events", "TEG and vascular surgery", "TEG and vascular", "TEG and endovascular surgery", "TEG and endovascular", "TEG and peripheral artery disease", "TEG and prediction of arterial events", "TEG and prediction of complications ", "TEG and prediction of thrombosis", "TEG and prediction of amputation", and "TEG and amputation" was performed in Cochrane and PubMed databases to identify all peer-reviewed studies of TEG utilization in vascular surgery, written between 2000-2021 in the English language. The free text and MeSH subheadings search terms included diagnosis, complications, physiopathology, surgery, mortality, and therapy to further restrict the articles. Studies were excluded if they were not in humans or pertaining to vascular or endovascular surgery. Additionally, case reports and studies with limited information regarding TEG utilization were excluded. Each study was independently reviewed by two researchers to assess for eligibility.

RESULTS

Of the 262 studies identified through the MeSH strategy, 15 studies met inclusion criteria and were reviewed and summarized. Literature on TEG utilization in vascular surgery spanned cerebrovascular disease (n=3), peripheral arterial disease (n=3), arteriovenous malformations (n=1), venous thromboembolic events (n=7), and perioperative bleeding and transfusion (n=1). In cerebrovascular disease, TEG may predict the presence and stability of carotid plaques, analyze platelet function before carotid stenting, and compare efficacy of antiplatelet therapy after stent deployment. In peripheral arterial disease, TEG has been used to predict disease severity and analyze the impact of contrast on coagulation parameters. In venous disease, TEG may predict hypercoagulability and thromboembolic events among various patient populations. Finally, TEG can be utilized in the postoperative setting to predict hemorrhage and transfusion requirements.

CONCLUSIONS

This systematic review provides an up-to-date summarization of TEG utilization in multiple facets of vascular and endovascular surgery.

Female participation in U.S. oncology clinical trials registered on ClinicalTrials.gov from 2008 to 2020

85

Background: Females are thought to be underrepresented in clinical trials, which may lead to care disparities. We characterized female enrollment trends in U.S. oncology trials registered on ClinicalTrials.gov and identified features associated with accurate representation. Methods: We employed a cross-sectional study design with descriptive, logistic regression, and cox regression analyses. We downloaded 270,172 studies registered on the Aggregate Analysis of the ClinicalTrials.gov database from October 1, 2008 to March 9, 2020, excluding non-interventional and reproductive organ specific trials. We then applied cancer/oncology specific Medical Subject Heading terms and manually reviewed the remaining 27,521 trials for true oncology content. Prevalence-corrected estimates for female participation were calculated as the percentage of females among trial participants divided by the percentage of females in the disease population per U.S. Surveillance, Epidemiology, and End Results Program (SEER) data (participation to prevalence ratio [PPR]), with a range between 0.8 and 1.2 reflecting accurate female representation in the trial. Results: Of 26,894 trials meeting eligibility criteria, 9,059 trials were completed in the U.S., 2,499 trials reported completed study status, and only 1,256 trials reported sex. Among 1,256 oncology trials and 229,056 participants, overall female representation was 46.9% (95% CI, 45.4-48.4%). 43% of trials were industry funded, 29% academic, and 28% U.S. government. Females were underrepresented compared to their disease burden in anal canal (PPR 0.21), thyroid (PPR 0.57), stomach (PPR 0.68), kidney (PPR 0.77), and bone (PPR 0.79) cancer trials. They were accurately represented in head and neck (PPR 0.80), lung (PPR 0.84), bladder (PPR 0.85), skin (PPR 0.88), pancreas (PPR 0.88), colon (PPR 0.90), hematologic (PPR 0.91), liver (PPR 1.01), CNS (PPR 1.03), soft tissue (PPR 1.05), and esophagus (PPR 1.05) cancer trials. Accurate representation was significantly associated with industry funding and pancreas cancer trial focus, but not associated with trial type (medical, surgical, radiation, other invasive, other) (Table). Conclusions: Females are underrepresented compared to their disease burden in many solid tumor clinical trials. Stakeholders can look to industry funded and pancreas cancer trials as models of improvement, but must increase female representation in clinical trials to improve cancer care. [Table: see text]

The surgical oncology clinical trial landscape: A cross-sectional analysis of ClinicalTrials.gov from 2008-2020

1561

Background: Surgical interventions are studied less often than medical or radiation interventions in oncology clinical trials. We characterized surgical oncology trials registered on ClinicalTrials.gov, analyzed funding sources and identified features associated with early discontinuation and results reporting. Methods: We employed a cross-sectional study design with descriptive, logistic regression, cox regression, time series and survival analyses. We downloaded all 270,172 studies registered on the Aggregate Analysis of the ClinicalTrials.gov database from October 1, 2008 to March 9, 2020. After excluding non-interventional trials, applying cancer/oncology specific Medical Subject Heading terms to the remaining trials and excluding phase 1 trials, 27,915 trials were identified for manual review. Primary exposure variables were trial focus: neoplasia site and treatment modality (surgical interventions included investigations of outcomes from surgical resection or intra-operative/peri-operative changes), and funding: industry, U.S. government, academic. Results: 26,815 trials were found to have true oncology content; 1,661 (6.2%) involved surgical oncology, representing 311,789 patients. Funding sources were: 82.7% by academic institutions, 10.9% by industry, and 6.2% by U.S. government. The most studied neoplasia sites were colorectal (17.4% of trials), breast (10.7%), gastric (10.5%), hepatic (8.6%), lung (7.5%), brain/CNS (6.7%) and cervical (6.6%). U.S. government funded surgical oncology trials had the lowest risk of early discontinuation (adjusted HR 0.50, 95% CI: 0.26-0.99, p<0.047) and the highest odds of results reporting (adjusted OR 1.08, 95% CI: 0.55-2.11, p=0.83) (Table 1). Conclusions: There is a paucity of surgical oncology clinical trials compared to other treatment modalities, especially in context of surgery’s role in overall cancer care. From 2008-2020 only 6.2% of trials focused on surgical oncology, and U.S. government funded trials displayed the lowest hazard of early discontinuation and highest odds of results reporting. Stakeholders should look to government funded trials as models of improvement, but must increase representation and results dissemination of surgical oncology trials to guide treatment recommendations. Surgical oncology trial features and associated early discontinuation/results reporting. [Table: see text]

The Effects of the Combined Argatroban/Nitric Oxide-Releasing Polymer on Platelet Microparticle-Induced Thrombogenicity in Coated Extracorporeal Circuits

Clotting, anticoagulation, platelet consumption, and poor platelet function are major factors in clinical extracorporeal circulation (ECC). We have shown that nitric oxide-releasing (NOReL) coatings prevent thrombosis in a rabbit model of ECC without systemic anticoagulation. Nitric oxide-releasing prevents platelet adhesion and activation, resulting in preserved platelet count and function. Previous work has shown that activated platelets form platelet-derived microparticles (PMPs). These experiments were designed to determine if PMPs can identify platelet function during ECC. The objective of this study is to investigate the effects of NOReL on platelet activation and PMP formation during ECC. Uncoated ECCs, including with and without systemic heparin, and NOReL-coated ECCs, including DBHD/N2O2 and argatroban (AG)/DBHD/N2O2-coated ECCs without systemic heparin, were tested in a 4-hour rabbit thrombogenicity model. Before and after ECC exposure, platelets were stimulated with collagen, and PMPs were measured using flow cytometry. The uncoated ECCs clotted within the first hour, while the NOReL-coated ECCs circulated for 4 hours. During pre-ECC blood exposure, platelets stimulated with collagen produced PMPs. With post-ECC exposure, platelets from uncoated circuits generated less PMPs than baseline (mean ± SDs: 23246 ± 3611 baseline vs. 1300 ± 523 uncoated post circuit, p = 0.018) when stimulated with collagen. However, platelets from the AG/DBHD/N2O2-coated ECCs generated a greater number of PMPs as baseline values (23246 ± 3611 baseline vs. 37040 ± 3263 AG/DBHD/N2O2 post 4 hours circuit, p = 0.023). Blood exposure during ECC results in platelet activation and clotting in uncoated ECCs. The remaining circulating platelets have lost function, as demonstrated by the low PMP formation in response to collagen. AG/DBHD/N2O2-coated ECCs prevented significant platelet activation and clotting, while DBHD/N2O2 trended towards prevention of platelet activation. In addition, function of the circulating platelets was preserved, as demonstrated by PMP formation in response to collagen. These results indicate that PMPs may be an important measure of platelet activation during ECC. Platelet-derived microparticles may provide a simplified way to measure platelet function during clinical ECC.

Industry Compensation to Physician Vascular Specialist Authors of Highly-referenced Aortic Aneurysm Studies

BACKGROUND

Industry payments to physicians may influence their attitudes toward medical devices and products. Disclosure of industry compensation by authors of scientific manuscripts usually occurs at the authors' discretion and is seldom audited as part of the peer review process. The purpose of this analysis was to characterize industry compensation among highly cited research articles related to aortic aneurysm.

METHODS

A Web of Science search for English language articles published from 2013-2017 using the search term "aortic aneurysm" identified publications for this study. The top 99 most-cited publications were abstracted by author. Physician authors with reported industry compensation from 2013-2016 were identified using the ProPublica Dollars for Docs search tool (linked to Centers for Medicare and Medicaid Services Open Payments data), based on provider name, medical specialty, and geographic location. Statistical analysis included descriptive statistics and categorical tests.

RESULTS

The 99 articles had 1,264 unique authors, of whom 105 physicians (8.3%) received industry compensation during the study period. Fourteen of the 105 authors self-reported having received industry compensation. The remaining 91 authors (86.7%) did not disclose their industry-reported compensation. Industry payments during the study period totaled $6,082,574 paid through 13,489 transactions from 169 different manufacturers. In-kind items and services were the most common form of payment (65.3%). The median transaction amount was $58.32. [$138.34]. Food and beverage accounted for the largest number of transactions (N=9653), followed by travel and lodging (N=2365), consulting (N=513), and promotional speaking (N=436). Consulting accounted for the most total dollars over the study period ($1,970,606), followed by travel and lodging ($1,122,276), promotional speaking ($972,894), food and beverage ($568,251), royalty or license ($504,631), honoraria ($452,167), and education ($428,489). Royalty and license payments had the highest median transaction amount ($15,418. [$29,049]), and was the only category with a median transaction amount greater than $5,000. In contrast, several categories had median transaction amounts under $50, including food and beverage ($32. [$77]), gifts ($34. [$86]), and entertainment ($30. [$69]). No significant difference in payment amounts by medical specialty was identified (P=0.071).

CONCLUSIONS

Only 8.3% of physician authors of highly cited aortic aneurysm studies received industry compensation, but 86.7% of those physician authors receiving payments did not disclose industry compensation within the manuscripts. Potential bias associated with industry compensation may be underestimated and conservatively biased based on author self-reporting.

The impact of the COVID-19 pandemic on children with autism spectrum disorders

In the unprecedented disruption and social isolation of the COVID-19 pandemic, families around the world are faced with questions of how their children can thrive in these conditions. On top of the ubiquitous challenges for all children, this public health crisis imparts unique difficulties for children with special health needs. We identify children with Autism Spectrum Disorder (ASD) as being particularly vulnerable to negative impacts of the COVID-19 pandemic. In this paper, we examine why children with ASD are uniquely vulnerable, recommend strategies to mitigate these stressors for children with ASD and their parents, explore the potential challenges of reintegration into society as conditions improve, and examine the obligations of healthcare and community stakeholders to support these families.

Circadian variation in the release of small extracellular vesicles can be normalized by vesicle number or TSG101

Numerous candidate biomarkers in urine extracellular vesicles (EVs) have been described for kidney diseases, but none are yet in clinical use, possibly due to a lack of proper normalization. Proper normalization corrects for normal biological variation in urine flow rate or concentration, which can vary by over one order of magnitude. Here, we observed inter- and intra-animal variation in urine excretion rates of small EVs (<200 nm in diameter) in healthy rats as a series of six 4-h fractions. To visualize intra-animal variation, we normalized a small EV excretion rate to a peak excretion rate, revealing a circadian pattern for each rat. This circadian pattern was distinct from urine volume, urine albumin, urine creatinine, and urine albumin-to-creatinine ratio. Furthermore, urine small EV excretion was not significantly altered by sex, food/water deprivation, or ischemic acute kidney injury. Urine excretion of the exosomal/small EV marker protein tumor susceptibility gene 101 (TSG101) displayed a similar circadian pattern to urine small EV excretion; both measurements were highly correlated (R² = 0.85), with an average stoichiometry of 10.0 molecules of TSG101/vesicle in healthy rats. The observed stoichiometry of TSG101/vesicle in rat urine translated to human spot urine samples (10.2 molecules/vesicle) and cultured kidney-derived cell lines (human embryonic kidney-293 and normal rat kidney 52E cells). Small EV number and its surrogate, TSG101 protein, can normalize for circadian variation when testing candidate biomarkers in small EVs. Just as creatinine has emerged as the customary normalization factor for liquid-phase urine biomarkers, vesicle number and its surrogate, molecules of exosome/small EV-associated TSG101, should be considered as viable, normalizing factors for small EV biomarkers.

The role of adenosine 1a receptor signaling on GFR early after the induction of sepsis

Sepsis and acute kidney injury (AKI) synergistically increase morbidity and mortality in the ICU. How sepsis reduces glomerular filtration rate (GFR) and causes AKI is poorly understood; one proposed mechanism includes tubuloglomerular feedback (TGF). When sodium reabsorption by the proximal tubules is reduced in normal animals, the macula densa senses increased luminal sodium chloride, and then adenosine-1a receptor (A1aR) signaling triggers tubuloglomerular feedback, reducing GFR through afferent arteriole vasoconstriction. We measured GFR and systemic hemodynamics early during cecal ligation and puncture-induced sepsis in wild-type and A1aR-knockout mice. A miniaturized fluorometer was attached to the back of each mouse and recorded the clearance of FITC-sinistrin via transcutaneous fluorescence to monitor GFR. Clinical organ injury markers and cytokines were measured and hemodynamics monitored using implantable transducer telemetry devices. In wild-type mice, GFR was stable within 1 h after surgery, declined by 43% in the next hour, and then fell to less than 10% of baseline after 2 h and 45 min. In contrast, in A1aR-knockout mice GFR was 37% below baseline immediately after surgery and then gradually declined over 4 h. A1aR-knockout mice had similar organ injury and inflammatory responses, albeit with lower heart rate. We conclude that transcutaneous fluorescence can accurately monitor GFR and detect changes rapidly during sepsis. Tubuloglomerular feedback plays a complex role in sepsis; initially, TGF helps maintain GFR in the 1st hour, and over the subsequent 3 h, TGF causes GFR to plummet. By 18 h, TGF has no cumulative effect on renal or extrarenal organ damage.