Genomic Analyses from Non-invasive Prenatal Testing Reveal Genetic Associations, Patterns of Viral Infections, and Chinese Population History.

We analyze whole-genome sequencing data from 141,431 Chinese women generated for non-invasive prenatal testing (NIPT). We use these data to characterize the population genetic structure and to investigate genetic associations with maternal and infectious traits. We show that the present day distribution of alleles is a function of both ancient migration and very recent population movements. We reveal novel phenotype-genotype associations, including several replicated associations with height and BMI, an association between maternal age and EMB, and between twin pregnancy and NRG1. Finally, we identify a unique pattern of circulating viral DNA in plasma with high prevalence of hepatitis B and other clinically relevant maternal infections. A GWAS for viral infections identifies an exceptionally strong association between integrated herpesvirus 6 and MOV10L1, which affects piwi-interacting RNA (piRNA) processing and PIWI protein function. These findings demonstrate the great value and potential of accumulating NIPT data for worldwide medical and genetic analyses.

Greater strength of selection and higher proportion of beneficial amino acid changing mutations in humans compared with mice and Drosophila melanogaster.

Quantifying and comparing the amount of adaptive evolution among different species is key to understanding how evolution works. Previous studies have shown differences in adaptive evolution across species; however, their specific causes remain elusive. Here, we use improved modeling of weakly deleterious mutations and the demographic history of the outgroup species and ancestral population and estimate that at least 20% of nonsynonymous substitutions between humans and an outgroup species were fixed by positive selection. This estimate is much higher than previous estimates, which did not correct for the sizes of the outgroup species and ancestral population. Next, we jointly estimate the proportion and selection coefficient (p + and s +, respectively) of newly arising beneficial nonsynonymous mutations in humans, mice, and Drosophila melanogaster by examining patterns of polymorphism and divergence. We develop a novel composite likelihood framework to test whether these parameters differ across species. Overall, we reject a model with the same p + and s + of beneficial mutations across species and estimate that humans have a higher p+s + compared with that of D. melanogaster and mice. We show that this result cannot be caused by biased gene conversion or hypermutable CpG sites. We discuss possible biological explanations that could generate the observed differences in the amount of adaptive evolution across species.

A new mRNA structure prediction based approach to identifying improved signal peptides for bone morphogenetic protein 2.

BACKGROUND: Signal peptide (SP) engineering has proven able to improve production of many proteins yet is a laborious process that still relies on trial and error. mRNA structure around the translational start site is important in translation initiation and has rarely been considered in this context, with recent improvements in in silico mRNA structure potentially rendering it a useful predictive tool for SP selection. Here we attempt to create a method to systematically screen candidate signal peptide sequences in silico based on both their nucleotide and amino acid sequences. Several recently released computational tools were used to predict signal peptide activity (SignalP), localization target (DeepLoc) and predicted mRNA structure (MXFold2). The method was tested with Bone Morphogenetic Protein 2 (BMP2), an osteogenic growth factor used clinically for bone regeneration. It was hoped more effective BMP2 SPs could improve BMP2-based gene therapies and reduce the cost of recombinant BMP2 production. RESULTS: Amino acid sequence analysis indicated 2,611 SPs from the TGF-ß superfamily were predicted to function when attached to BMP2. mRNA structure prediction indicated structures at the translational start site were likely highly variable. The five sequences with the most accessible translational start sites, a codon optimized BMP2 SP variant and the well-established hIL2 SP sequence were taken forward to in vitro testing. The top five candidates showed non-significant improvements in BMP2 secretion in HEK293T cells. All showed reductions in secretion versus the native sequence in C2C12 cells, with several showing large and significant decreases. None of the tested sequences were able to increase alkaline phosphatase activity above background in C2C12s. The codon optimized control sequence and hIL2 SP showed reasonable activity in HEK293T but very poor activity in C2C12. CONCLUSIONS: These results support the use of peptide sequence based in silico tools for basic predictions around signal peptide activity in a synthetic biology context. However, mRNA structure prediction requires improvement before it can produce reliable predictions for this application. The poor activity of the codon optimized BMP2 SP variant in C2C12 emphasizes the importance of codon choice, mRNA structure, and cellular context for SP activity.

Haplotype tagging reveals parallel formation of hybrid races in two butterfly species.

Genetic variation segregates as linked sets of variants or haplotypes. Haplotypes and linkage are central to genetics and underpin virtually all genetic and selection analysis. Yet, genomic data often omit haplotype information due to constraints in sequencing technologies. Here, we present "haplotagging," a simple, low-cost linked-read sequencing technique that allows sequencing of hundreds of individuals while retaining linkage information. We apply haplotagging to construct megabase-size haplotypes for over 600 individual butterflies (Heliconius erato and H. melpomene), which form overlapping hybrid zones across an elevational gradient in Ecuador. Haplotagging identifies loci controlling distinctive high- and lowland wing color patterns. Divergent haplotypes are found at the same major loci in both species, while chromosome rearrangements show no parallelism. Remarkably, in both species, the geographic clines for the major wing-pattern loci are displaced by 18 km, leading to the rise of a novel hybrid morph in the center of the hybrid zone. We propose that shared warning signaling (Müllerian mimicry) may couple the cline shifts seen in both species and facilitate the parallel coemergence of a novel hybrid morph in both comimetic species. Our results show the power of efficient haplotyping methods when combined with large-scale sequencing data from natural populations.

ECHO "Bootcamp": An Innovative Training Model to Onboard Providers in the Care of Gender Diverse Patients.

Purpose: Extension for Community Health Outcomes (ECHO) is a model of continuing medical education meant to connect academic medical center-based specialists with community providers to increase capacity in managing complex health conditions. The purpose of this study was to evaluate the effectiveness of a shortened "bootcamp" ECHO model in increasing participant competence with topics related to transgender and gender diverse (TGD) health care and the impact of "bootcamp" participation on enrollment in an ongoing ECHO series. Methods: An ongoing monthly ECHO series was instituted on topics of TGD health. After 2 years, the team implemented a four-session "bootcamp" for four consecutive weeks during March 2022 to introduce foundational topics for new participants who had joined or were considering joining the ongoing series. Qualitative and quantitative results were collected from self-reported pre-/post-surveys as well as from in-session quizzes. Results: There were 71 participants in the "bootcamp" including health care providers and support staff. Attendees reported a 10.3% increase (p = 0.02) in self-reported comfort providing care to transgender patients. Pre-/post-knowledge improved in areas of health inequities (50% vs. 74% correct pre/post), surgical requirements (33% vs. 74%), and effects of masculinizing (55% vs. 70%) and feminizing (64% vs. 89%) hormone therapy. Prescribing providers reported a significant change across four areas of practice competency. Among 71 "bootcamp" participants, 15 registered for the ongoing program. Conclusion: Use of a "bootcamp" highlights ways to increase participant comfort and knowledge in providing TGD health care in a shortened timeframe and recruit new participants to an ongoing ECHO curriculum.

The Role of High-Fidelity Simulation in the Acquisition of Endovascular Surgical Skills: A Systematic Review.

BACKGROUND: The widespread introduction of minimally invasive endovascular techniques in cardiovascular surgery has necessitated a transition in the psychomotor skillset of trainees and surgeons. Simulation has previously been used in surgical training; however, there is limited high-quality evidence regarding the role of simulation-based training on the acquisition of endovascular skills. This systematic review aimed to systematically appraise the currently available evidence regarding endovascular high-fidelity simulation interventions, to describe the overarching strategies used, the learning outcomes addressed, the choice of assessment methodology, and the impact of education on learner performance. METHODS: A comprehensive literature review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement using relevant keywords to identify studies evaluating simulation in the acquisition of endovascular surgical skills. References of review articles were screened for additional studies. RESULTS: A total of 1,081 studies were identified (474 after removal of duplicates). There was marked heterogeneity in methodologies and reporting of outcomes. Quantitative analysis was deemed inappropriate due to the risk of serious confounding and bias. Instead, a descriptive synthesis was performed, summarizing key findings and quality components. Eighteen studies were included in the synthesis (15 observational, 2 case-control and 1 randomized control studies). Most studies measured procedure time, contrast usage, and fluoroscopy time. Other metrics were recorded to a lesser extent. Significant reductions were noted in both procedure and fluoroscopy times with the introduction of simulation-based endovascular training. CONCLUSIONS: The evidence regarding the use of high-fidelity simulation in endovascular training is very heterogeneous. The current literature suggests simulation-based training leads to improvements in performance, mostly in terms of procedure and fluoroscopy time. High-quality randomized control trials are needed to establish the clinical benefits of simulation training, sustainability of improvements, transferability of skills and its cost-effectiveness.

The Impact of the COVID-19 Pandemic on a Dedicated Vascular Emergency Clinic.

BACKGROUND: Vascular Emergency Clinics (VEC) improve patient outcomes in chronic limb-threatening ischemia (CLTI). They provide a "1 stop" open access policy, whereby "suspicion of CLTI" by a healthcare professional or patient leads to a direct review. We assessed the resilience of the outpatient VEC model to the first year of the coronavirus disease (COVID-19) pandemic. METHODS: A retrospective review of a prospectively maintained database of all patients assessed in our VEC for lower limb pathologies between March 2020 and April 2021 was performed. This was cross-referenced to national and loco-regional Governmental COVID-19 data. Individuals with CLTI were further analysed to determine Peripheral Arterial Disease-Quality Improvement Framework compliance. RESULTS: Seven hundred and ninety one patients attended for 1,084 assessments (Male n = 484, 61%; Age 72.5 ± standard deviation 12.2 years; White British n = 645, 81.7%). In total, 322 patients were diagnosed with CLTI (40.7%). A total of 188 individuals (58.6%) underwent a first revascularization strategy (Endovascular n = 128, 39.8%; Hybrid n = 41, 12.7%; Open surgery n = 19, 5.9%; Conservative n = 134, 41.6%). Major lower limb amputation rate was 10.9% (n = 35) and mortality rate was 25.8% (n = 83) at 12 months of follow-up. Median referral to assessment time was 3 days (interquartile range: 1-5). For the nonadmitted patient with CLTI, the median assessment to intervention was 8 days (interquartile range: 6-15) and median referral to intervention time of 11 days (11-18). CONCLUSIONS: The VEC model has demonstrated strong resilience to the COVID-19 pandemic with rapid treatment timelines maintained for patients with CLTI.

The Association Between Sexual Identity, Depression, and Adolescent Substance Use.

Sexual minority youth (SMY) represent a population vulnerable to several adverse health consequences. Specifically, SMY experience depression and substance use at substantially higher rates than heterosexual peers. Better understanding the relationship between depression and substance use among SMY may help reduce morbidity and mortality. We hypothesize that depression will moderate increased substance use rates seen in SMY. Weighted logistical analyses of covariance, adjusted for race/ethnicity, sex, and age, compared the relationship between sexual identity, depression, and substance use (14 outcomes), using data from the 2019 Youth Risk Behavior Survey (n = 13,677) of high school students. SMY reported depression at rates nearly double than heterosexual peers (63.9% vs 33.0%). Except for vaping and alcohol, SMY had significantly higher odds of all SU (aORs 1.41-2.45, p < 0.001-0.0011). After adjusting for depression, odds of all SMY substance use decreased; most relationships remained significant (aORs 0.73-1.89), though the relationship between SMY and lifetime cannabis use became non-significant. The relationship between SMY and current vaping became significant and the relationship between SMY and alcohol and binge-drinking remained non-significant. SMY are at higher risk for use of most substances and depression compared to heterosexual youth. As depression consistently plays a role in the relationship between sexual minority status and adolescent substance use across a wide variety of substances, it may be a modifiable risk factor for substance use among sexual minority youth that should be screened for and treated. This study additionally provides important information for future studies examining nuances of SMY substance use patterns.

Inferring Population Histories for Ancient Genomes Using Genome-Wide Genealogies.

Ancient genomes anchor genealogies in directly observed historical genetic variation and contextualize ancestral lineages with archaeological insights into their geography and cultural associations. However, the majority of ancient genomes are of lower coverage and cannot be directly built into genealogies. Here, we present a fast and scalable method, Colate, the first approach for inferring ancestral relationships through time between low-coverage genomes without requiring phasing or imputation. Our approach leverages sharing patterns of mutations dated using a genealogy to infer coalescence rates. For deeply sequenced ancient genomes, we additionally introduce an extension of the Relate algorithm for joint inference of genealogies incorporating such genomes. Application to 278 present-day and 430 ancient DNA samples of >0.5x mean coverage allows us to identify dynamic population structure and directional gene flow between early farmer and European hunter-gatherer groups. We further show that the previously reported, but still unexplained, increase in the TCC/TTC mutation rate, which is strongest in West Eurasia today, was already present at similar strength and widespread in the Late Glacial Period ~10k-15k years ago, but is not observed in samples >30k years old. It is strongest in Neolithic farmers, and highly correlated with recent coalescence rates between other genomes and a 10,000-year-old Anatolian hunter-gatherer. This suggests gene-flow among ancient peoples postdating the last glacial maximum as widespread and localizes the driver of this mutational signal in both time and geography in that region. Our approach should be widely applicable in future for addressing other evolutionary questions, and in other species.

Crypt4GH: a file format standard enabling native access to encrypted data.

MOTIVATION: The majority of genome analysis tools and pipelines require data to be decrypted for access. This potentially leaves sensitive genetic data exposed, either because the unencrypted data is not removed after analysis, or because the data leaves traces on the permanent storage medium. RESULTS: : We defined a file container specification enabling direct byte-level compatible random access to encrypted genetic data stored in community standards such as SAM/BAM/CRAM/VCF/BCF. By standardizing this format, we show how it can be added as a native file format to genomic libraries, enabling direct analysis of encrypted data without the need to create a decrypted copy. AVAILABILITY AND IMPLEMENTATION: The Crypt4GH specification can be found at: http://samtools.github.io/hts-specs/crypt4gh.pdf. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Refget: standardized access to reference sequences.

MOTIVATION: Reference sequences are essential in creating a baseline of knowledge for many common bioinformatics methods, especially those using genomic sequencing. RESULTS: We have created refget, a Global Alliance for Genomics and Health API specification to access reference sequences and sub-sequences using an identifier derived from the sequence itself. We present four reference implementations across in-house and cloud infrastructure, a compliance suite and a web report used to ensure specification conformity across implementations. AVAILABILITY AND IMPLEMENTATION: The refget specification can be found at: https://w3id.org/ga4gh/refget. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Long-Term Effects of Acute Kidney Injury Following Endovascular Femoropopliteal Intervention: Insights From a Multicenter Trial.

PURPOSE: To examine the association between acute kidney injury (AKI) severity and duration with cardiovascular mortality, following endovascular treatment of femoropopliteal disease, and whether it is AKI in itself that confers an increased risk of cardiovascular mortality. METHODS: A retrospective analysis of prospectively collected data obtained between 2014 and 2019 from 3 vascular centers. Renal function was followed up for a minimum of 90 days. Electronic records were queried to establish a cause of death, where applicable. Patients were excluded if unable to provide written informed consent or if presenting with acute limb ischemia. Primary outcomes were the hazard ratios for cardiovascular death (AKI patients vs no AKI; no AKI vs stage 1 AKI vs stage 3 AKI; and no AKI vs transient AKI vs established AKI). Propensity score-matched analysis was used to establish whether developing AKI, in patients with similar demographics and procedural characteristics, is associated with a higher risk of cardiovascular death. RESULTS: Overall 239 patients developed AKI, and this was associated with an increased risk of cardiovascular mortality (hazard risk [HR]: 4.3, 95% confidence intervals [CIs]: 2.1-6.8, pairwise comparison p value=0.006]. This was dependent on the severity of the AKI stage (HR 5.4, 95% CI: 2.4-7.3, pairwise comparison p value=0.01) and duration (HR 4.2, 95% CI: 2.3-6.2, pairwise comparison p value=0.04). The propensity score-matched analysis showed that even when patients are matched for comorbidity and procedural characteristics, AKI confers an increased risk of mortality (p=0.04). CONCLUSIONS: Acute kidney injury is common after femoropopliteal endovascular therapy. It confers an increased risk of long-term cardiovascular mortality, which is still present when renal decline is transient, and highest for patients with established decline in renal function. CLINICAL IMPACT: This is the first study in the setting of peripheral arterial disease to show that acute kidney injury has an adverse effect on cardiovascular mortality, in the long-term, that is dependent on its severity, and present even when the AKI is transient. We have also shown that this difference in cardiovascular mortality becomes more pronounced from the medium-term, and thus closer follow-up of these patients is required.

Editor's Choice - Covered vs. Bare Metal Stents in the Reconstruction of the Aortic Bifurcation: Early and Midterm Outcomes from the COBRA European Multicentre Registry.

OBJECTIVE: To report outcomes following endovascular revascularisation for severe aorto-iliac occlusive disease (AIOD) using covered (CS) or bare metal (BMS) stent(s). METHODS: This was a retrospective cohort study including patients who underwent treatment with CS or BMS for AIOD between November 2012 and March 2020 in 12 European centres. Outcome measures included death, freedom from target lesion revascularisation (TLR), major amputation, and major adverse cardiac and cerebrovascular events (MACCE). RESULTS: Overall, 252 patients (53% males; mean age 65 ± 10 years) were included (102 with a bare metal and 150 with a covered aortic stent); 122 (48%) presented with chronic limb threatening ischaemia (CLTI). Severe arterial calcification was noted in > 65% of patients, 70% presented with Trans-Atlantic Societies Consensus (TASC) D lesions, 32% and 46% had aortic or iliac chronic total occlusion (CTO), respectively. Median follow up was 17 months (range 6 - 40; none lost to follow up). Median inpatient stay was two days (range two to four). During the first 30 days, two patients died (both with covered aortic stents, because of cardiovascular events), none required TLR, two (1%) patients had a major amputation (all presented with CLTI), and three (1%) had a MACCE. At 17 months, mortality (BMS 14% vs. CS 7%, hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.42 - 2.26, p = .94, log rank test) and TLR (11% vs. 10%, HR 1.98, 95% CI 0.89 - 4.43, p = .095) did not differ statistically significantly between the two groups; only three patients had a major limb amputation during late follow up (all with a covered stent). In a multivariable model, the use of an aortic CS did not influence TLR. In a conditional Cox regression, however, the concomitant use of aortic and iliac CSs was associated with improved freedom from TLR. CONCLUSION: Endovascular reconstruction with aortic CSs or BMSs for severe AIOD showed comparable midterm performance. The use of both aortic and iliac CSs seems to be associated with reduced TLR.

The Relationship Between Obesity and Amputation-free Survival in Patients Undergoing Lower-limb Revascularisation for Chronic Limb-threatening Ischaemia: A Retrospective Cohort Study.

BACKGROUND: The obesity paradox is a well-documented phenomenon in cardiovascular disease, however it remains poorly understood. We aimed to investigate the relationship between body mass (as measured by body mass index [BMI]) and 1-year amputation-free survival (AFS) for patients undergoing lower limb revascularisation for chronic limb-threatening ischaemia (CLTI). METHODS: A retrospective analysis was undertaken of all consecutive patients undergoing lower limb revascularisation for CLTI at the Leicester Vascular Institute between February 2018-19. Baseline demographics and outcomes were collected using electronic records. BMI was stratified using the World Health Organization criteria. One-year AFS (composite of major amputation/death) was the primary outcome. Kaplan-Meier survival analysis and adjusted Cox's proportional hazard models were used to compare groups to patients of normal mass. RESULTS: One-hundred and ninety patients were included. Overall, no difference was identified in 1-year AFS across all groups (pooled P = 0.335). Compared to patients with normal BMI (n = 66), obese patients (n = 43) had a significantly lower adjusted combined risk of amputation/death (aHR 0.39, 95% CI 0.16-0.92, P = 0.032), however no significant differences were observed for overweight (aHR 0.89, 95% CI 0.47-1.70, P = 0.741), morbidly obese (aHR 1.15, 95% CI 0.41-3.20, P = 0.797) and underweight individuals (aHR 1.86, 95% CI 0.56-6.20, P = 0.314). CONCLUSIONS: In the context of CLTI, obesity is potentially associated with favourable amputation-free survival at 1 year, compared to normal body mass. The results of this study support the notion of an obesity paradox existing within CLTI and question whether current guidance on weight management requires a more patient-specific approach.

The Impact of Anemia on One-Year Amputation-Free Survival in Patients Undergoing Revascularization for Chronic Limb-Threatening Ischemia: A Retrospective Cohort Study.

BACKGROUND: Anemia is potentially associated with increased morbidity and mortality following vascular surgery procedures. This study investigated whether peri-procedural anemia is associated with reduced 1-year amputation-free survival (AFS) in patients undergoing revascularization for chronic limb-threatening ischemia (CLTI). METHODOLOGY: A retrospective analysis of patients diagnosed with CLTI between February 2018-February 2019, who subsequently underwent revascularization, was conducted. Hemoglobin concentration measured at index assessment was recorded and stratified by WHO criteria. Subsequent peri-procedural red blood cell transfusions (RBC) were also recorded. The primary outcome was 1-year AFS. Kaplan Meier survival analysis and Cox's proportional hazard modelling were conducted to assess the effect of anemia and peri-procedure transfusion on outcomes. RESULTS: 283 patients were analyzed, of which 148 (52.3%) were anemic. 53 patients (18.7%) underwent RBC transfusion. Patients with anemia had a significantly lower 1-year AFS (64.2% vs. 78.5%, P = 0.009). A significant difference in 1-year AFS was also observed based upon anemia severity (P = 0.008) and for patients who received RBC transfusion (45.3% vs 77.0%, P < 0.001). On multivariable analysis, moderately severe anemia was independently associated with increased risk of major amputation/death (aHR 1.90, 95% CI 1.06-3.38, P = 0.030). After adjusting for severity of baseline anemia, peri-procedural RBC transfusion was associated with a significant increase in the combined risk of major amputation/death (aHR 3.15, 95% CI 1.91-5.20, P < 0.001). CONCLUSION: Moderately severe peri-procedural anemia and subsequent RBC transfusion are independently associated with reduced 1-year AFS in patients undergoing revascularization for CLTI. Future work should focus on investigating alternative measures to managing anemia in this cohort.

Diversity and characterization of temperate bacteriophages induced in Pasteurella multocida from different host species.

BACKGROUND: Bacteriophages play important roles in the evolution of bacteria and in the emergence of new pathogenic strains by mediating the horizontal transfer of virulence genes. Pasteurella multocida is responsible for different disease syndromes in a wide range of domesticated animal species. However, very little is known about the influence of bacteriophages on disease pathogenesis in this species. RESULTS: Temperate bacteriophage diversity was assessed in 47 P. multocida isolates of avian (9), bovine (8), ovine (10) and porcine (20) origin. Induction of phage particles with mitomycin C identified a diverse range of morphological types representing both Siphoviridae and Myoviridae family-types in 29 isolates. Phage of both morphological types were identified in three isolates indicating that a single bacterial host may harbour multiple prophages. DNA was isolated from bacteriophages recovered from 18 P. multocida isolates and its characterization by restriction endonuclease (RE) analysis identified 10 different RE types. Phage of identical RE types were identified in certain closely-related strains but phage having different RE types were present in other closely-related isolates suggesting possible recent acquisition. The host range of the induced phage particles was explored using plaque assay but only 11 (38%) phage lysates produced signs of infection in a panel of indicator strains comprising all 47 isolates. Notably, the majority (9/11) of phage lysates which caused infection originated from two groups of phylogenetically unrelated ovine and porcine strains that uniquely possessed the toxA gene. CONCLUSIONS: Pasteurella multocida possesses a wide range of Siphoviridae- and Myoviridae-type bacteriophages which likely play key roles in the evolution and virulence of this pathogen.

Treatment of Aortoiliac Occlusive Disease With the Covered Endovascular Reconstruction of the Aortic Bifurcation (CERAB) Technique: Results of a UK Multicenter Study.

OBJECTIVE: This UK multicenter study aims to report early- and medium-term results following covered endovascular reconstruction of aortic bifurcation (CERAB) for the treatment of aortoiliac occlusive disease (AIOD) in patients with chronic limb threatening ischemia (CLTI) or intermittent claudication (IC). MATERIALS AND METHODS: Retrospective case analysis was performed of patients who underwent CERAB between November 1, 2012 and March 31, 2020 in 6 centers across the United Kingdom. Anatomical data, including degree of plaque calcification, were assessed using preoperative imaging. Outcome measures included mortality, perioperative complications, target lesion reintervention (TLR), and major limb amputation. Primary, assisted primary, and secondary patencies were calculated at set intervals. RESULTS: A total of 116 patients underwent CERAB over the study period for the following reasons [48% presenting with CLTI (Rutherford 4-6) and 52% with IC (Rutherford 1-3)]; 82% presented had Trans-Atlantic Inter-Society Consensus (TASC) D AIOD disease. Median age was 65 years (range 42-90 years); 76% of the cohort were male. Severely calcified aortic and iliac lesions were noted in 90% and 80% of patients, respectively. Over a median follow-up of 18 months (range 1-91 months), 2 (1.7%) patients were lost to follow up. In total 5, (4.3%) patients died and 2 (1.7%) had a major amputation. Endovascular TLR was required in 14 (12.1%) patients at last follow up. Surgical TLR was performed in 4 (3.4%) patients at last follow-up. Seven (6%) patients developed an aortic/iliac stent occlusion at last follow-up. The Kaplan-Meier (KM) freedom from TLR at 1 year was 94% and KM 1-year primary patency, assisted primary patency, and secondary patency were 88%, 94%, and 98% respectively. Subanalysis found the following features were associated with need for TLR; TASC D disease (OR = 2.45, 95% CI 1.44 to 3.71), severe aortic calcification (OR = 2.01, 95% CI 1.03 to 2.20), and presence of tissue loss at baseline (OR = 1.43, 95% CI 1.01 to 4.63). CONCLUSION: Perioperative (<30 days) and medium-term morbidity, mortality, and patency rates in this pragmatic cohort of patients with severe AIOD lesions show that CERAB is a valid revascularization option. A direct comparison with surgical treatments for AIOD in a randomized controlled trial is justified.

Does the Introduction of a Vascular Limb Salvage Service Improve One Year Amputation Outcomes for Patients with Chronic Limb-Threatening Ischaemia?

OBJECTIVE: Vascular limb salvage services are recommended by the Global Vascular Guidelines to help improve outcomes for patients with chronic limb-threatening ischaemia (CLTI), although their description within the literature is limited. This study reports the 12 month outcomes for an outpatient based vascular limb salvage (VaLS) clinic. METHODS: An analysis of a prospectively maintained database, involving all consecutive patients diagnosed with CLTI within the VaLS clinic from February 2018-February 2019, was undertaken. Data were compared with two comparator cohorts, identified from coding data: 1) patients managed prior to the clinic, between May 2017 and February 2018 (Pre-Clinic [PC]); and 2) patients managed outside of clinic, between February 2018 and February 2019 (Alternative Pathways [AP]). Freedom from major amputation at 12 months was the primary outcome. Kaplan-Meier plots and adjusted Cox's proportional hazard models (aHR) were used to compare outcomes. RESULTS: Five hundred and sixty-six patients (VaLS 158, AP 173, PC 235) were included (median age 74 years). Patients managed within the VaLS cohort were statistically significantly more likely to be free from major amputation (90.5%) compared with both the AP (82.1%, aHR 0.52, 95% confidence interval [CI] 0.28 - 0.98, p = .041) and the PC (80.0%; aHR 0.50, 95% CI 0.28 - 0.91, p = .022) cohorts at 12 months, after adjustment for age, disease severity, and presence of diabetes. CONCLUSION: This study supports the recommendations of the Global Vascular Guidelines that vascular limb salvage clinics may improve the rate of major amputation. Furthermore, the study provides a reproducible service model that delivers timely vascular assessment in an ambulatory setting. Further evaluation is required to assess longer term outcomes.

Exome sequencing identifies rare LDLR and APOA5 alleles conferring risk for myocardial infarction.

Myocardial infarction (MI), a leading cause of death around the world, displays a complex pattern of inheritance. When MI occurs early in life, genetic inheritance is a major component to risk. Previously, rare mutations in low-density lipoprotein (LDL) genes have been shown to contribute to MI risk in individual families, whereas common variants at more than 45 loci have been associated with MI risk in the population. Here we evaluate how rare mutations contribute to early-onset MI risk in the population. We sequenced the protein-coding regions of 9,793 genomes from patients with MI at an early age (≤50 years in males and ≤60 years in females) along with MI-free controls. We identified two genes in which rare coding-sequence mutations were more frequent in MI cases versus controls at exome-wide significance. At low-density lipoprotein receptor (LDLR), carriers of rare non-synonymous mutations were at 4.2-fold increased risk for MI; carriers of null alleles at LDLR were at even higher risk (13-fold difference). Approximately 2% of early MI cases harbour a rare, damaging mutation in LDLR; this estimate is similar to one made more than 40 years ago using an analysis of total cholesterol. Among controls, about 1 in 217 carried an LDLR coding-sequence mutation and had plasma LDL cholesterol > 190 mg dl(-1). At apolipoprotein A-V (APOA5), carriers of rare non-synonymous mutations were at 2.2-fold increased risk for MI. When compared with non-carriers, LDLR mutation carriers had higher plasma LDL cholesterol, whereas APOA5 mutation carriers had higher plasma triglycerides. Recent evidence has connected MI risk with coding-sequence mutations at two genes functionally related to APOA5, namely lipoprotein lipase and apolipoprotein C-III (refs 18, 19). Combined, these observations suggest that, as well as LDL cholesterol, disordered metabolism of triglyceride-rich lipoproteins contributes to MI risk.

Associations of Clinical Frailty with Severity of Limb Threat and Outcomes in Chronic Limb-threatening Ischaemia.

OBJECTIVE: Investigate the relationship of frailty and severity of chronic limb-threatening ischaemia (CLTI), and their comparative associations with one-year outcomes, in patients presenting to a vascular limb salvage (VaLS) clinic. METHODS: This retrospective cohort study utilised data collected from a prospectively maintained VaLS clinic database. Patients aged ≥50 presenting to the VaLS clinic with CLTI between February 2018 and April 2019 were included. Frailty was measured using the Clinical Frailty Scale (CFS) and limb threat severity by the Wound, Ischaemia, and foot Infection (WIfI) score. Excessive polypharmacy was defined as ≥10 medications. Anticholinergic burden (ACB) score and Charlson comorbidity index (CCI) were calculated for all patients. The primary outcome measure was a composite endpoint of death or amputation at one-year. Associations with outcome were assessed using Cox regression and reported as hazards ratios (HR) with 95% confidence intervals (CI). RESULTS: A total of 198 patients were included, with CFS scores available for 190 patients. 98 patients (52%) were frail (CFS ≥5). 127 patients (67%) initially underwent endovascular revascularisation. Excessive polypharmacy was common (55 patients; 28%). Frailty was associated with increased WIfI stage (P = 0.025) as well as age, female sex, CCI score, number of medications, excessive polypharmacy but not ACB score. Frail patients were more frequently managed non-operatively (P = 0.017). Frailty (HR 1.91; 95% CI 1.09, 3.34; P = 0.024) and WIfI stage 4 (HR 3.29; 95%CI 1.23, 8.80; P = 0.018) were associated with death or amputation on univariable analysis. WIfI stage 4 (HR 2.80; 95%CI 1.04, 7.57; P = 0.042) and CCI score (HR 1.21; 95%CI 1.03, 1.41; P = 0.015), but not frailty (HR 1.25; 95%CI 0.67, 2.33; P = 0.474), were independently associated with death or amputation on multivariable analysis. CONCLUSIONS: Frailty is highly prevalent among CLTI patients and related to severity of limb threat. The CFS may be a useful adjunct to patient risk assessment in CLTI.