Clot composition and recanalization outcomes in mechanical thrombectomy

BACKGROUND

Mechanical thrombectomy (MT) has become standard for large vessel occlusions, but rates of complete recanalization are suboptimal. Previous reports correlated radiographic signs with clot composition and a better response to specific techniques. Therefore, understanding clot composition may allow improved outcomes.

METHODS

Clinical, imaging, and clot data from patients enrolled in the STRIP Registry from September 2016 to September 2020 were analyzed. Samples were fixed in 10% phosphate-buffered formalin and stained with hematoxylin-eosin and Martius Scarlett Blue. Percent composition, richness, and gross appearance were evaluated. Outcome measures included the rate of first-pass effect (FPE, modified Thrombolysis in Cerebral Infarction 2c/3) and the number of passes.

RESULTS

A total of 1430 patients of mean±SD age 68.4±13.5 years (median (IQR) baseline National Institutes of Health Stroke Scale score 17.2 (10.5-23), IV-tPA use 36%, stent-retrievers (SR) 27%, contact aspiration (CA) 27%, combined SR+CA 43%) were included. The median (IQR) number of passes was 1 (1-2). FPE was achieved in 39.3% of the cases. There was no association between percent histological composition or clot richness and FPE in the overall population. However, the combined technique resulted in lower FPE rates for red blood cell (RBC)-rich (P<0.0001), platelet-rich (P=0.003), and mixed (P<0.0001) clots. Fibrin-rich and platelet-rich clots required a higher number of passes than RBC-rich and mixed clots (median 2 and 1.5 vs 1, respectively; P=0.02). CA showed a trend towards a higher number of passes with fibrin-rich clots (2 vs 1; P=0.12). By gross appearance, mixed/heterogeneous clots had lower FPE rates than red and white clots.

CONCLUSIONS

Despite the lack of correlation between clot histology and FPE, our study adds to the growing evidence supporting the notion that clot composition influences recanalization treatment strategy outcomes.

Assessment of spatially offset Raman spectroscopy to detect differences in bone matrix quality

Since spatially offset Raman spectroscopy (SORS) can acquire biochemical measurements of tissue quality through light scattering materials, we investigated the feasibility of this technique to acquire Raman bands related to the fracture resistance of bone. Designed to maximize signals at different offsets, a SORS probe was used to acquire spectra from cadaveric bone with and without skin-like tissue phantoms attenuating the light. Autoclaving the lateral side of femur mid-shafts from 5 female and 5 male donors at 100 °C and again at 120 °C reduced the yield stress of cortical beams subjected to three-point bending. It did not affect the volumetric bone mineral density or porosity. Without tissue phantoms, autoclaving affected more Raman characteristics of the organic matrix when determined by peak intensity ratios, but fewer matrix properties depended on the three offsets (5 mm, 6 mm, and 7 mm) when determined by band area ratios. The cut-off in the thickness of the tissue phantom layers was ∼4 mm for most properties, irrespective of offset. Matching trends when spectra were acquired without phantom layers between bone and the probe, ν1PO43-/Amide III and ν1PO43-/(proline + OH-proline) were higher and lower in the non-treated bone than in the autoclaved bone, respectively, when the thickness of tissue phantom layers was 4 mm. The layers, however, caused a loss of sensitivity to autoclaving-related changes in ν3CO3/ν1PO43- and crystallinity. Without advanced post-processing of Raman spectra, SORS acquisition through turbid layers can detect changes in Raman properties of bone that accompany a loss in bone strength.

Design and rationale of a prospective, randomized, non-inferiority trial to determine the safety and efficacy of the Biolimus A9™ drug coated balloon for the treatment of in-stent restenosis: First-in-man trial (REFORM)

BACKGROUND

Drug-coated balloon (DCB) angioplasty with paclitaxel-eluting devices is an established treatment for coronary in-stent restenosis (ISR). Biolimus A9™ (BA9), a sirolimus analogue with enhanced lipophilicity, may facilitate enhanced local drug delivery into vascular tissue. A novel DCB coated with Biolimus A9™ represents an alternative to traditional paclitaxel- and sirolimus-coated devices. Hence, we sought to investigate the safety and efficacy of this novel DCB in the treatment of coronary ISR.

METHODS AND DESIGN

REFORM (NCT04079192) is a prospective, multicenter, single blind, randomized controlled trial comparing the BA9-DCB (Biosensors Europe SA, Morges, Switzerland) to the paclitaxel-coated SeQuent® Please DCB (Braun Melsungen AG, Germany) in the treatment of coronary ISR. A total of 201 patients with coronary artery disease and an indication for interventional treatment of ISR in a bare-metal stent (BMS) or drug-eluting stent (DES) have been randomized 2:1 to receive treatment with the BA9- or the paclitaxel-DCB comparator. Patients were enrolled across 24 investigational centers in Europe and Asia. The primary endpoint is percent diameter stenosis (%DS) of the target segment as assessed by quantitative coronary angiography (QCA) at 6 months. Key secondary endpoints are in-stent late lumen loss, binary restenosis, target lesion failure, target vessel failure, myocardial infarction and death at 6 months. Subjects will be followed for 24 months from enrolment.

IMPLICATIONS

The REFORM trial will seek to prove that the BA9-DCB is non-inferior to the standard paclitaxel-DCB comparator in the treatment of coronary ISR with respect to %DS at 6 months and has similar safety characteristics.

Glu298Asp variant of the endothelial nitric oxide synthase gene and acute coronary syndrome or premature coronary artery disease: A systematic review and meta-analysis

INTRODUCTION

Several published studies have reported an association between the Glu298Asp polymorphism (rs1799983), residing in the endothelial nitric oxide synthase (NOS3) gene, and lower levels of circulating nitric oxide, as well as an increased risk of coronary artery disease (CAD). However, association status of this genetic variant with acute coronary syndrome (ACS) or premature CAD (PCAD) is still unclear. Against this background, we conducted a systematic review and study level meta-analysis to assess the association of the NOS3 Glu298Asp polymorphism with ACS or PCAD.

MATERIALS AND METHODS

A comprehensive online search to identify relevant studies was performed on several databases including PubMed, EMBASE, MEDLINE, Scopus, Cochrane library and Web of Science. The identified studies were stratified into two ancestral subgroups: 'European ancestry' and 'All other ancestries combined'. Study level odds ratios (ORs) and their 95% confidence intervals (CI) were pooled using random/fixed effects employing a Z test.

RESULTS

Out of a total of 195 distinct records identified through online search, 37 articles with 39 different studies, with a total sample size of 27,441 (11,516 cases/15,925 controls) were included for quantitative synthesis. Pooled results suggested significant associations of the NOS3 Glu298Asp polymorphism with ACS or PCAD through dominant as well as allelic genetic models (p ≤ 0.002), primarily driven by the 'All other ancestries combined' subgroup. The 'All other ancestries combined' subgroup demonstrated an additional risk of 36% for ACS or PCAD, through both dominant and allelic genetic models (OR = 1.36, 95%CI = 1.13, 1.63, p = 0.001 and OR = 1.36, 95%CI = 1.14, 1.61, p = 0.0005 respectively). On the other hand, the 'European ancestry' subgroup did not show any significant associations. Sensitivity analysis and a sub-analysis for the myocardial infarction endpoint further supported these observed associations.

CONCLUSIONS

This meta-analysis indicates towards an association between the NOS3 Glu298Asp polymorphism and ACS or PCAD, predominantly driven by 'All other ancestries combined' subgroup. In contrast, the 'European ancestry' subgroup did not demonstrate any significant association. Further large-scale investigations are required to confirm our derived results.

Performance assessment of probe-based Raman spectroscopy systems for biomedical analysis

We present a methodology for evaluating the performance of probe-based Raman spectroscopy systems for biomedical analysis. This procedure uses a biological standard sample and data analysis approach to circumvent many of the issues related to accurately measuring and comparing the signal quality of Raman spectra between systems. Dairy milk is selected as the biological standard due to its similarity to tissue spectral properties and because its homogeneity eliminates the dependence of probe orientation on the measured spectrum. A spectral dataset is first collected from milk for each system configuration, followed by a model-based correction step to remove photobleaching artifacts and accurately calculate SNR. Results demonstrate that the proposed strategy, unlike current methods, produces an experimental SNR that agrees with the theoretical value. Four preconfigured imaging spectrographs that share similar manufacturer specifications were compared, showing that their capabilities to detect biological Raman spectra widely differ in terms of throughput and stray light rejection. While the methodology is used to compare spectrographs in this case, it can be adapted for other purposes, such as optimizing the design of a custom-built Raman spectrometer, evaluating inter-probe variability, or examining how altering system subcomponents affects signal quality.

Multimodal Raman spectroscopy and optical coherence tomography for biomedical analysis

Optical techniques hold great potential to detect and monitor disease states as they are a fast, non-invasive toolkit. Raman spectroscopy (RS) in particular is a powerful label-free method capable of quantifying the biomolecular content of tissues. Still, spontaneous Raman scattering lacks information about tissue morphology due to its inability to rapidly assess a large field of view. Optical Coherence Tomography (OCT) is an interferometric optical method capable of fast, depth-resolved imaging of tissue morphology, but lacks detailed molecular contrast. In many cases, pairing label-free techniques into multimodal systems allows for a more diverse field of applications. Integrating RS and OCT into a single instrument allows for both structural imaging and biochemical interrogation of tissues and therefore offers a more comprehensive means for clinical diagnosis. This review summarizes the efforts made to date toward combining spontaneous RS-OCT instrumentation for biomedical analysis, including insights into primary design considerations and data interpretation.

Abstract 99: Clot Composition And Reperfusion Outcomes In 1430 Mechanical Thrombectomy Patients: Analysis Of The Stroke Thromboembolism Registry Of Imaging And Pathology

Background: Understanding clot composition may allow for better technical planning and improved outcomes in mechanical thrombectomy (MT). We sought to correlate clot composition with reperfusion outcomes in MT.

Methods: Clinical, imaging, and clot data from patients enrolled in the STRIP Registry from September 2016 to September 2020 were analyzed. Samples were fixed in 10% phosphate-buffered formalin and stained with hematoxylin and eosin and Martius Scarlett Blue. Percent composition, richness, and gross appearance were evaluated. Outcome measures included the rate of First-Pass Effect (mTICI2c/3, FPE) and the number of device passes.

Results: A total of 1430 patients (mean age, 68.4±13.5years; median [IQR] baseline NIHSS,17.2 [10.5-23]; IV-tPA use, 36%; Stent-Retrievers [SR], 27%; Contact Aspiration [CA], 27%; Combined SR + CA, 43%) were included. The median [IQR] number of passes was 1 [1-2]. FPE was achieved in 39.3% of the cases. There was no association between percent histological composition or clot richness and FPE in the overall population. However, the combined technique resulted in lower FPE rates for RBC-rich (P<0.0001), platelet-rich (P=0.003), and mixed (P<0.0001) clots. Fibrin-rich and platelet-rich clots required a higher number of passes compared to RBC-rich and mixed clots (median, 2 and 1.5 vs.1, respectively, P=0.02). CA displayed a trend towards a higher number of passes with fibrin-rich clots (2 vs.1, P=0.12). By gross appearance, mixed/heterogeneous clots had lower FPE rates than red and white clots.

Conclusion: Despite the lack of correlation between clot histology and FPE in the overall population, our study adds to the growing body of evidence supporting the notion that clot composition influences reperfusion treatment strategy outcomes. Additional studies are needed.

Sex-specific Inequalities in the Treatment of Severely Calcified Coronary Lesions: A Sub-analysis of the PREPARE-CALC Trial

Background: Coronary vessels in women may have anatomical and histological particularities. The aim of this study was to investigate sex-specific characteristics and outcomes of patients with calcified coronary arteries in the Prepare-CALC (Comparison of Strategies to Prepare Severely Calcified Coronary Lesions) trial. Methods: The Prepare-CALC trial randomised patients with severe coronary calcification to coronary lesion preparation either using modified balloons (MB; cutting or scoring) or rotational atherectomy (RA). Results: Of 200 randomised patients, 24% were women. Strategy success in general was similar between women (93.8%) and men (88.2%; p=0.27). For men, strategy success was significantly more common with an RA-based strategy than an MB-based strategy (98.7% in the RA group versus 77.3% in the MB group, p<0.001), whereas for women there was no evidence of a significant difference in strategy success between RA and MB (95.7% in the RA group versus 92% in the MB group, p>0.99, p for interaction between sex and treatment strategy=0.03). Overall, significant complications such as death, MI, stent thrombosis, bypass operation and perforations were rare and did not differ significantly by gender or treatment strategy. Plaque rupture and disrupted calcified nodules were more common in women. Conclusion: In a well-defined patient population with severely calcified coronary arteries, lesion preparation with an RA-strategy was superior to an MB-strategy in men. For women, both RA and MB strategies appear to have a similar success rate, although definitive conclusions are limited due to the small number of women in the trial.

Toward biophysical markers of depression vulnerability

A major difficulty with treating psychiatric disorders is their heterogeneity: different neural causes can lead to the same phenotype. To address this, we propose describing the underlying pathophysiology in terms of interpretable, biophysical parameters of a neural model derived from the electroencephalogram. We analyzed data from a small patient cohort of patients with depression and controls. Using DCM, we constructed biophysical models that describe neural dynamics in a cortical network activated during a task that is used to assess depression state. We show that biophysical model parameters are biomarkers, that is, variables that allow subtyping of depression at a biological level. They yield a low dimensional, interpretable feature space that allowed description of differences between individual patients with depressive symptoms. They could capture internal heterogeneity/variance of depression state and achieve significantly better classification than commonly used EEG features. Our work is a proof of concept that a combination of biophysical models and machine learning may outperform earlier approaches based on classical statistics and raw brain data.

Rotational Atherectomy or Balloon-Based Techniques to Prepare Severely Calcified Coronary Lesions

BACKGROUND

The comparative efficacy of percutaneous techniques for the preparation of calcified lesions before stenting remains poorly studied.

OBJECTIVES

This study sought to compare the performance of up-front rotational atherectomy (RA) or balloon-based techniques before drug-eluting stent implantation in severely calcified coronary lesions as assessed by angiography and optical coherence tomography (OCT).

METHODS

Patient-level data from the PREPARE-CALC (Comparison of Strategies to Prepare Severely Calcified Coronary Lesions) and ISAR-CALC (Comparison of Strategies to Prepare Severely Calcified Coronary Lesions) randomized trials were pooled. The primary endpoint was stent expansion as assessed by OCT imaging. The secondary endpoints included stent eccentricity, stent asymmetry, angiographic acute lumen gain, strategy success and in-hospital occurrence of cardiac death, target vessel myocardial infarction, and repeat revascularization.

RESULTS

Among 274 patients originally randomized, 200 participants with available OCT data after lesion preparation with RA (n = 63), a modified balloon (MB, n = 103), or a super high-pressure balloon (n = 34) before stenting were analyzed. The use of RA versus MB or a super high-pressure balloon led to comparable stent expansion (73.2% ± 11.6% vs 70.8% ± 13.6% vs 71.8% ± 12.2%, P = 0.49) and stent asymmetry (P = 0.83). Compared with RA or MB, a super high-pressure balloon was associated with less stent eccentricity (P = 0.03) with a numerically higher acute lumen gain, albeit not significantly different (P = 0.08). Strategy success was more frequent with RA versus MB (P = 0.002) and numerically more frequent with RA versus a super high-pressure balloon (P = 0.06). Clinical outcomes did not differ between groups.

CONCLUSIONS

In patients with severely calcified lesions undergoing drug-eluting stent implantation, lesion preparation with RA, MB, or a super high-pressure balloon was associated with comparable stent expansion. A super high-pressure balloon is associated with less stent eccentricity, whereas strategy success is more frequent with RA.

A review of the selection process and decontamination methods with the use of face shields in UV phototherapy during the SARS‐CoV‐2 pandemic

Targeted ultraviolet (UV) phototherapy has been used in the management of a wide variety of dermatological clinical conditions including moderate to severe psoriasis unresponsive to topical therapies, vitiligo, severe atopic dermatitis and lymphoproliferative disorders. To date there are no uniform, standardised guidelines for the selection and decontamination process for UV personal protective equipment (PPE) and facial shields used in phototherapy. In the current climate, Coronavirus 2019 (COVID‐19) pandemic, standards regarding all decontamination and disinfection processes are under significant scrutiny. In terms of the UV‐PPE and facial shields used in phototherapy, careful disinfection procedures need to be implemented to ensure that the decontamination practice is effective enough to neutralise the virulent virus whilst maintaining maximal protection to the user from UV‐rays and safeguard the equipment from damage during the cleaning process. The aim of this report is to provide an evidence based review of the current and international practice standards guiding the selection, use and decontamination processes of UV facial shields in phototherapy. The complications and concerns that the COVID‐19 pandemic has had on this practice is highlighted. As such, we performed a comprehensive evaluation of the literature to provide recommendations as to the most effective, time efficient and safest practices for disinfection and decontamination of UV facial shields used in phototherapy during these unprecedented times.

Focused multivector ultraviolet (FMUV) technology rapidly eradicates SARS-CoV-2 in-vitro: Implications for hospital disinfection of COVID-19 environments

Focused Multivector Ultraviolet technology rapidly killed the SARS-CoV-2 coronavirus in-vitro. Plates were inoculated with a mean of greater than 10⁶ plaque forming units of USA-WA1 Washington index patient strain of SARS-CoV-2 and exposed to ultraviolet, resulting in mean reductions of 99.99% within 30 seconds, 99.999% within 60 seconds, and 99.9999% within 90 seconds. These results support the effectiveness of Focused Multivector Ultraviolet technology for SARS-CoV-2 disinfection.

Angiographic predictors of unplanned rotational atherectomy in complex calcified coronary artery disease: a pooled analysis from the randomised ROTAXUS and PREPARE-CALC trials

BACKGROUND

Calcified coronary lesions present therapeutic challenges for the interventional cardiologist, often requiring rotational atherectomy (RA).

AIMS

This study aimed to develop an angiographic scoring tool to predict the need for a priori RA.

METHODS

A pooled analysis of the randomised ROTAXUS and PREPARE-CALC studies was carried out, (N=220 patients, N=313 lesions), by virtue of the fact that both studies made provision for crossover to RA (from balloon dilatation or modified balloon dilatation, respectively). Logistical regression techniques were employed to assess for the presence of patient- or lesion-specific factors leading to a necessity for RA. External validation was performed though retrospective calculation of the score for 192 patients who underwent bail-out RA in a single centre.

RESULTS

Lesion length (odds ratio [OR] 1.02, 95% confidence interval [CI]: 1.00-1.04 per mm, p=0.04), bifurcation lesion (OR 2.60, 95% CI: 1.27-5.30, p=0.009), vessel tortuosity >45° (OR 3.49, 95% CI: 1.73-7.03, p<0.001) and severe vessel calcification (OR 11.60, 95% CI: 3.40-39.64, p<0.001) were predictive of the need for RA in multivariate analysis. Based on the regression coefficients, a scoring system was devised. The greater the score, the more likely a lesion required RA. The scoring system performed well in the external validation cohort, with 78% of patients crossing over having a score of greater than the proposed cut-off of 3.

CONCLUSIONS

We provide an angiographic scoring tool to support the expeditious use of time and resources, allowing assessment of the likelihood of success of a balloon-based strategy, or the necessity for RA.

Mechanical Chest Compressions and Intra-Aortic Balloon Pump Combination for Refractory Ventricular Fibrillation During Primary PCI

This case highlights the successful resuscitation of a 43-year-old man with ST-segment elevation myocardial infarction and refractory ventricular fibrillation by using a combination of mechanical chest compressions and intra-aortic balloon pump insertion. This bailout strategy facilitated primary multivessel percutaneous coronary intervention in a center without on-site extracorporeal membrane oxygenation. (Level of Difficulty: Advanced.)

259 IDENTIFYING THE TOP 10 RESEARCH PRIORITIES FOR FAMILY CARERS: THE INTERFACE PROJECT

Background

In assessing the global impact of the COVID-19 pandemic on society, it is important to understand the communities most affected and develop methods of support. Family carers provide a vital, yet often invisible role in our society and healthcare system. Identifying research priorities for carers helps establish overall gaps in the research agenda and increases awareness of the role of carers in the community.

Methods

A priority setting partnership methodology was engaged and through collaboration with carers, healthcare professionals and researchers, a participatory process was conducted to identify gaps in the current literature and prioritise research questions and uncertainties. Focus group discussions followed, the first consisted of family carers (n = 5). The second (n = 3) interviewed stakeholders namely healthcare professionals, researchers and policy makers. After collating the data, researchable questions were developed through an iterative process with a Multi Stakeholder Advisory Committee to identify the top 10 research priorities for Family Carers Ireland.

Results

The top 10 researchable questions were distilled from a list of 16 and fit into 7 broad categories. 1) economic impact and financial strain 2) Systemic issues, education, resources and policy 3) technology 4) support services and infrastructure 5) mental health and wellbeing of the carer 6) carers in society 7) Recognition and acknowledgment of the family carer.

Conclusion

The partnership focus of this project allowed the ‘ground-up’ development of research priorities for carers by carers. The COVID-19 pandemic served to magnify systemic issues already present in society, as well as highlight new burdens. As a result, the subsequent development of 10 researchable questions will guide further investigation to improve the support and wellbeing of family carers.

1080 An Audit on Compliance with Recommended Duration of Surgical Antimicrobial Prophylaxis in St. Vincent’s University Hospital, Dublin, Ireland

Aim

Surgical site infection (SSI) is a common healthcare-associated infection, and a frequent cause of post-operative morbidity. SSI comprises any infection of the operative incision, cavity or involved organ, that occurs within the 30-day post-operative period. Antimicrobial prophylaxis is critical in reducing SSIs. Our aim was to assess adherence to the recommended surgical antimicrobial prophylaxis guidelines in St. Vincent’s University Hospital (SVUH), as part of the hospital antimicrobial stewardship programme. Compliance of surgical services was measured against the recommended regimens described in the SVUH Antimicrobial Guidelines.

Method

Data on duration and choice of prophylaxis were prospectively gathered on inpatients undergoing elective surgery during a three-week period between August-September 2020. Patients undergoing transplant procedures, inpatients in the intensive care unit, and patients who moved off-site postoperatively were excluded.

Results

Eighty-one patients were included. Sixty-four (79%) were compliant with prophylaxis duration, while seventeen (21%) were not. Reasons for extended prophylaxis included three (18%) cases where there were intra-operative complications and five (29%) cases of routine prescribing of an additional 24-hour coverage. Nine (53%) did not document the reason for extended cover.

Conclusions

Compliance with recommended duration of prophylaxis improved in comparison to prior audits. Among patients receiving extended prophylaxis, documentation of the indication was poor. Patients with evidence of post-operative infection may be better served with targeted antimicrobial therapy rather than extended prophylaxis. One reason for extended prophylaxis may be due to difficulty accessing guidelines on recommended prophylaxis duration, hence a targeted smartphone application was introduced to improve accessibility.

Are medical procedures that induce coughing or involve respiratory suctioning associated with increased generation of aerosols and risk of SARS-CoV-2 infection? A rapid systematic review

BACKGROUND

The risk of transmission of SARS-CoV-2 from aerosols generated by medical procedures is a cause for concern.

AIM

To evaluate the evidence for aerosol production and transmission of respiratory infection associated with procedures that involve airway suctioning or induce coughing/sneezing.

METHODS

The review was informed by PRISMA guidelines. Searches were conducted in PubMed for studies published between January 1st, 2003 and October 6th, 2020. Included studies examined whether nasogastric tube insertion, lung function tests, nasendoscopy, dysphagia assessment, or suctioning for airway clearance result in aerosol generation or transmission of SARS-CoV-2, SARS-CoV, MERS, or influenza. Risk of bias assessment focused on robustness of measurement, control for confounding, and applicability to clinical practice.

FINDINGS

Eighteen primary studies and two systematic reviews were included. Three epidemiological studies found no association between nasogastric tube insertion and acquisition of respiratory infections. One simulation study found low/very low production of aerosols associated with pulmonary lung function tests. Seven simulation studies of endoscopic sinus surgery suggested significant increases in aerosols but findings were inconsistent; two clinical studies found airborne particles associated with the use of microdebriders/drills. Some simulation studies did not use robust measures to detect particles and are difficult to equate to clinical conditions.

CONCLUSION

There was an absence of evidence to suggest that the procedures included in the review were associated with an increased risk of transmission of respiratory infection. In order to better target precautions to mitigate risk, more research is required to determine the characteristics of medical procedures and patients that increase the risk of transmission of SARS-CoV-2.

Management of cardiogenic shock

Despite the rapidly evolving evidence base in modern cardiology, progress in the area of cardiogenic shock remains slow, with short-term mortality still reaching 40-50%, relatively unchanged in recent years. Despite advances with an increase in the number of clinical trials taking place in this admittedly difficult-to-study area, the evidence base on which we make day-to-day decisions in clinical practice remains relatively sparse. With only definitive evidence for early revascularisation and the relative ineffectiveness of intra-aortic balloon pumping, most aspects of patient management are based on expert consensus, rather than randomised controlled trials. This updated 2020 review will outline the management of CS mainly after acute myocardial infarction with major focus on state-of-the-art treatment based on randomised clinical trials or matched comparisons if available.

Iatrogenic Foreign Materials Associated with Retrieved Clot Tissue via Mechanical Thrombectomy

BACKGROUND AND PURPOSE

Hydrophilic polymers and polytetrafluoroethylene liners, commonly used in the construction of endovascular devices, occasionally separate from devices with subsequent embolization. We determined the frequency of such materials in thrombus specimens retrieved by mechanical thrombectomy in patients with stroke.

MATERIALS AND METHODS

We retrospectively reviewed H&E-stained thrombus sections for presence and types of foreign materials. We identified 4 types of foreign materials-Type I: material was light green with refraction and had a homogeneous texture; type II: material was light gray and/or dark gray, thin, and loose or attenuated in texture; type III: material was light green with refraction, solitary in texture, irregular in shape, and was often associated with round or oval bubblelike particles and/or diffuse black particles; and type IV: material had homogeneous texture and was light pink or red. In addition, polymer materials from different layers of used mechanical thrombectomy catheters were compared with the foreign materials found in thrombus specimens.

RESULTS

A total of 101 thrombi were evaluated. Foreign materials were found in 53 (52.5%) thrombus samples. The most common type was type I (92%), followed by type II (30%). The histopathologic features of the polymer materials from mechanical thrombectomy catheters were similar to the foreign materials found in thrombus specimens. The inner polytetrafluoroethylene liner and coating layer of catheters resembled type I and type II of the foreign materials, respectively.

CONCLUSIONS

Foreign polymer materials are present in approximately half of retrieved thrombi, most commonly polytetrafluoroethylene from catheter liners and less from hydrophilic coatings.

Extracellular Vesicle Capture by AnTibody of CHoice and Enzymatic Release (EV-CATCHER): A customizable purification assay designed for small-RNA biomarker identification and evaluation of circulating small-EVs

Circulating nucleic acids, encapsulated within small extracellular vesicles (EVs), provide a remote cellular snapshot of biomarkers derived from diseased tissues, however selective isolation is critical. Current laboratory-based purification techniques rely on the physical properties of small-EVs rather than their inherited cellular fingerprints. We established a highly-selective purification assay, termed EV-CATCHER, initially designed for high-throughput analysis of low-abundance small-RNA cargos by next-generation sequencing. We demonstrated its selectivity by specifically isolating and sequencing small-RNAs from mouse small-EVs spiked into human plasma. Western blotting, nanoparticle tracking, and transmission electron microscopy were used to validate and quantify the capture and release of intact small-EVs. As proof-of-principle for sensitive detection of circulating miRNAs, we compared small-RNA sequencing data from a subset of small-EVs serum-purified with EV-CATCHER to data from whole serum, using samples from a small cohort of recently hospitalized Covid-19 patients. We identified and validated, only in small-EVs, hsa-miR-146a and hsa-miR-126-3p to be significantly downregulated with disease severity. Separately, using convalescent sera from recovered Covid-19 patients with high anti-spike IgG titers, we confirmed the neutralizing properties, against SARS-CoV-2 in vitro, of a subset of small-EVs serum-purified by EV-CATCHER, as initially observed with ultracentrifuged small-EVs. Altogether our data highlight the sensitivity and versatility of EV-CATCHER.

Impact on percutaneous coronary intervention for acute coronary syndromes during the COVID-19 outbreak in a non-overwhelmed European healthcare system: COVID-19 ACS-PCI experience in Ireland

AIMS

To evaluate temporal trends of acute coronary syndromes (ACS) treated via percutaneous coronary intervention (PCI) throughout the COVID-19 outbreak in a European healthcare system affected but not overwhelmed by COVID-19-related pathology.

METHODS AND RESULTS

We performed a retrospective multicentre analysis of the rates of PCI for the treatment of ACS within the period 2 months pre and post the first confirmed COVID-19 case in Ireland, as well as comparing PCI for ST-elevation myocardial infarction (STEMI) with the corresponding period in 2019. During the 2020 COVID-19 period (29 February-30 April 2020), there was a 24% decline in PCI for overall ACS (incidence rate ratio (IRR) 0.76; 95% CI 0.65 to 0.88; p<0.001), including a 29% reduction in PCI for non-ST-elevation ACS (IRR 0.71; 95% CI 0.57 to 0.88; p=0.002) and an 18% reduction in PCI for STEMI (IRR 0.82; 95% CI 0.67 to 1.01; p=0.061), as compared with the 2020 pre-COVID-19 period (1 January-28 February 2020). A 22% (IRR 0.78; 95% CI 0.65 to 0.93; p=0.005) reduction of PCI for STEMI was seen as compared with the 2019 reference period.

CONCLUSION

This study demonstrates a significant reduction in PCI procedures for the treatment of ACS since the COVID-19 outbreak in Ireland. The reasons for this decline are still unclear but patients need to be encouraged to seek medical attention when cardiac symptoms appear, in order to avoid incremental cardiac morbidity and mortality due to a reduction in coronary revascularisation for the treatment of ACS.

Diagnosis, clinical characteristics, and outcomes of COVID-19 patients from a large healthcare system in northern New Jersey

New Jersey was an early epicenter for the COVID-19 pandemic in the United States, yet information on hospitalized COVID-19 patients from this area is scarce. This study aimed to provide data on demographics and clinical features of a hospitalized patient population who were confirmed with infection by our in-house (CDI) real-time reverse-transcription polymerase chain reaction (RT-PCR) test. We included consecutive patients who were admitted to Hackensack Meridian Health system hospitals with laboratory-confirmed diagnoses of COVID-19 at Hackensack University Medical Center by the CDI virus test between March 12, 2020, and April 8, 2020. Clinical data and viral testing results were collected and analyzed for characteristics associated with outcomes, as well as the correlation with viral load. A total of 722 patients were included in the study, with a median age of 63 (interquartile range (IQR), 51–75) and 272 (37.7%) females. Mortality of this case series was 25.8%, with a statistically significant linear increase observed from age 40 to ≥ 80 by 10-year intervals. Viral load, as indicated by the cycle of threshold (Ct) values from the RT-PCR test, was significantly higher in the oldest patient group (≥ 80), and inversely correlated with survival. This is the first report to describe the clinical characteristics and outcomes in a large hospitalized COVID-19 patient series from New Jersey. Findings from this study are valuable to the ongoing response of both nationwide healthcare networks and the medical research community.

Proteomic Analysis of Cardioembolic and Large Artery Atherosclerotic Clots Using Reverse Phase Protein Array Technology Reveals Key Cellular Interactions Within Clot Microenvironments

Thrombus characteristics are dependent on clot composition, but identification of the etiology based on histological analysis has proved inconclusive. Identification of proteomic signatures may help to differentiate between clots of different etiologies such as cardioembolic, large artery atherosclerotic, and other known etiologies, information that could enhance an individualized medicine approach to secondary stroke prevention. In this study, total protein extracts from cardioembolic (n=25) and large artery atherosclerotic (n=23) thrombus specimens were arrayed in quadruplicate on nitrocellulose slides and immunostained for 31 proteins using a Dako Autostainer (Agilent Technologies, Inc., Santa Clara, USA). We quantified 31 proteins involved in platelet and/or endothelial function, inflammation, oxidative stress, and metabolism. Pathway analysis showed more heterogeneity and protein network interactions in the cardioembolic clots but no specific correlations with clot etiology. Reverse-phase protein arrays are a powerful tool for assessing cellular interactions within the clot microenvironment and may enhance understanding of clot formation and origination. This tool could be further explored to help in identifying stroke etiology in large vessel occlusion patients with embolic stroke of an undetermined source.

Asbestos Contamination in Talc-Based Cosmetics: An Invisible Cancer Risk

The lack of regulation and adequate testing of talc-containing personal care products in the U.S. has resulted in the contamination of cosmetics with asbestos. As such, the true exposure of consumers to asbestos is poorly characterized and likely underestimated. In this study, transmission electron microscopy analysis revealed that 3 of 21 powder-based cosmetic products tested were contaminated with amphibole asbestos. One of these contaminated products is expressly marketed for use by children. The presence of asbestos found in products demonstrates the urgency to revise cosmetics policy. Further, talc-based cosmetics may be an overlooked and difficult to characterize source of exposure to asbestos, a known carcinogen.

Advances in Optical Detection of Human-Associated Pathogenic Bacteria

Bacterial infection is a global burden that results in numerous hospital visits and deaths annually. The rise of multi-drug resistant bacteria has dramatically increased this burden. Therefore, there is a clinical need to detect and identify bacteria rapidly and accurately in their native state or a culture-free environment. Current diagnostic techniques lack speed and effectiveness in detecting bacteria that are culture-negative, as well as options for in vivo detection. The optical detection of bacteria offers the potential to overcome these obstacles by providing various platforms that can detect bacteria rapidly, with minimum sample preparation, and, in some cases, culture-free directly from patient fluids or even in vivo. These modalities include infrared, Raman, and fluorescence spectroscopy, along with optical coherence tomography, interference, polarization, and laser speckle. However, these techniques are not without their own set of limitations. This review summarizes the strengths and weaknesses of utilizing each of these optical tools for rapid bacteria detection and identification.

Dielectric profile of blood clots to inform ischemic stroke treatments

Platelet and fibrin-rich blood clots can respond differently to red blood cell rich clots during ischemic stroke treatment, which includes thrombolysis and mechanical thrombectomy. Currently, there is no accurate way to identify the type of clot in advance of treatment. If the type of blood clot can be identified, the optimum clot removal process can be chosen and patient outcomes can be improved. In this paper we fabricate physiologically relevant blood clot analogues from human blood, that cover a range of red blood cell, fibrin, and platelet concentrations. We characterize the dielectric profile of these formed clots using an open-ended coaxial probe method across a wide frequency range. After the dielectric measurements are completed, histology on each blood clot is performed to determine the concentration of red blood cells present. In total, 32 unique blood clots were measured.With this completed analysis, we investigate the correlation between the dielectric properties across this frequency range and the red blood cell count of the formed blood clots. Furthermore, we develop a model to predict whether an unknown blood clot can be categorized as red blood cell rich or platelet and fibrin-rich based solely on the measured dielectric properties.Clinical Relevance-Using the dielectric profile of a clot we can predict whether a clot is platelet and fibrin-rich or red blood cell rich allowing clinicians to more easily determine treatment methods during an intervention for ischemic stroke.

Abstract 147: Outcomes of the Stroke Thromboembolism Registry of Imaging and Pathology: A Multicenter International Study

Background: We performed a multicenter prospective clinical registry across 11 centers to study the association between histopathological characteristics of retrieved clots and imaging, stroke etiology and clinical outcomes.

Materials and Methods: Following IRB approval at the 11 centers, patients were enrolled in the STRIP registry. All retrieved emboli were sent for histopathological analysis with H&E and MSB staining. Demographic variables, comorbidities, stroke etiology, imaging findings and procedural details were collected for each case. We studied the association between clot histopathology and imaging findings, stroke etiology and and revascularization outcomes. Student’s t-test was used for continuous variables and chi-squared testing for categorical variables.

Results: To date, 1022 patients have been included. There was a significant correlation between platelet rich clots and the absence of hyperdensity on non-contrast CT [p=0.321, p=0.003) and a significant inverse correlation between the percentage of platelets and mean HU on NCCT (p=-0.243, p=0.025). The proportion of platelet-rich clots (55.0% versus 21.2%, p=0.005) and the percentage of platelet content (22.1% versus 13.9%, p=0.03) was significantly higher in patient with large artery atherosclerosis compared to those with a cardioembolic etiology. There was no correlation between RBC density, WBC density, fibrin density or platelet density and revascularization outcomes with stent-retrievers. However, we have found that with aspiration alone, patients with platelet rich clots are less likely to be fully revascularized (i.e. TICI 2c/3) than non-platelet rich clots (OR=0.36, 95%CI=0.12-0.81, P<.0001). Meanwhile, patients with RBC rich clots are more likely to be completely revascularized with aspiration alone than those with RBC poor clots (OR=2.71, 95%CI=1.25-3.24, P=0.02).

Conclusions: Interim analysis of the STRIP registry suggests that the platelet content of a clot may be the most revealing factor in determining a clot’s etiology, imaging features and revascularization outcome. Platelet rich clots are less dense on NCCT, are associated with a large artery atherosclerosis source and are less likely to be completely revascularized with aspiration alone.

Abstract WP268: Von Willebrand Factor Expression in Various Subtypes of Acute Ischemic Stroke

Introduction: Von Willebrand factor (VWF) is a key component of acute ischemic stroke (AIS) thrombi. The aim of our prospective study was to investigate the immunohistochemical expression of VWF in clots and to evaluate whether VWF is associated with certain subtypes of AIS.

Methods: VWF immunostaining was performed on 79 thrombi collected as part of the multi-center Stroke Thromboembolism Registry of Imaging and Pathology (STRIP) registry. The cases were classified according to TOAST criteria. The VWF expression was quantified using Orbit Image Analysis (www.Orbit.bio) machine learning software. IBM SPSS statistics 25 was used to assess the relationship between the VWF levels and different etiology subtypes.

Results: A cardioembolic stroke was defined in 39 cases (49.4%) whereas an atherosclerotic origin was identified in 13 patients (16.5%). Other causes accounted for 12 cases (15.1%). Unknown etiology was reported in 15 cases (19%). The mean VWF content in the clots was 12.8%. According to the Mann-Whitney U-test, the level of VWF was significantly higher in the cases with unknown etiology compared to cardioembolic origin (p=0.044). We found also that patients with unknown etiology of stroke had higher VWF expression as compared to the other two subtypes, although this difference was not statistically significant.

Conclusions: Among the patients with ischemic stroke included in this study, the VWF expression was significantly increased in those with unknown etiology compared to the group with cardioembolic stroke. Our finding provides new insights into clot composition in cryptogenic stroke and may influence the treatment and secondary prevention in these cases.

Incidence and prevalence of multiple sclerosis in persian gulf area: A systematic review and meta-analysis

BACKGROUND

There is an unapprehended diversity in the epidemiology of multiple sclerosis (MS) in different geographical regions. In this study, for the first time, we systematically review the studies estimating the incidence and/or prevalence of MS in the Persian Gulf area. The goal is to obtain the overall incidence and prevalence of MS and elucidate the reasons for the geographical variation.

METHODS

A comprehensive literature search was carried out using MEDLINE and EMBASE through articles published between January 1985 and December 2018 on MS epidemiology in Persian Gulf countries including Bahrain, Iran, Iraq, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates. Search terms included 'Multiple sclerosis', 'Incidence', 'Prevalence', 'Epidemiology', 'Persian Gulf', 'Arabian Gulf' and name of each country. Only full-text articles published in English were included. All abstracts were considered and two trained reviewers evaluated the study quality using an assessment tool specifically designed for this study.

RESULTS

39 studies met the inclusion criteria. The mean age at disease onset varied in each country and the pooled mean age of onset was 23.11. The overall pooled MS incidence was 5.03/100,000 person-years (95% CI: 0.04 - 10.02). Prevalence was 39.31/100,000 (95% CI: 29.12 - 49.50) and the result of the meta-regression method showed that prevalence increased by 2.3% per year between 1985-2018 (p = 0.04). Quality scores ranged from 4/7 to 8/8.

CONCLUSION

The prevalence and incidence of MS in the Persian Gulf region has gone through significant changes during the past decades. This study highlights the need for future studies of MS prevalence and incidence, which will further elucidate the possible etiologies leading to periodical and geographical variations in MS incidence.

Visual Immunoprecipitate Assay (VIP) for Listeria monocytogenes and Related Listeria Species Detection in Selected Foods: Collaborative Study

Six foods representing a variety of food products were analyzed by the Assurance Listeria polyclonal enzyme immunoassay (EIA) and by either the Bacteriological Analytical Manual or the U.S. Department of Agriculture culture method for detecting Listeria monocytogenes and related Listeria species. Samples of each food type, at each inoculation level, were analyzed simultaneously by both methods. A total of 19 laboratories representing federal government agencies and private industry in the United States and Canada participated. Food types were inoculated with Listeria species including L. monocytogenes, with the exception of 3 lots of green beans, which were naturally contaminated. During this study, 1764 samples and controls were analyzed and confirmed, of which 492 were positive and 947 were negative by both methods. There were 159 samples that were positive by culture method but negative by the EIA and 188 that were negative by culture method but positive by EIA. Twenty-two samples were negative by EIA and by culture method but confirmed positive when Assurance selective enrichment broths were subcultured to selective agar. The Assurance polyclonal EIA for detecting L. monocytogenes and related Listeria species in foods has been adopted first action by AOAC INTERNATIONAL.

Evaluation of the Assurance GDS® for Salmonella Method in Foods and Environmental Surfaces: Multilaboratory Collaborative Study

A multilaboratory collaborative study was conducted to compare the detection of Salmonella by the Assurance GDS® for Salmonella method and the Reference culture methods. Six foods, representing a variety of low microbial and high microbial load foods were analyzed. Seventeen laboratories in the United States and Canada participated in this study. No statistical differences (P &lt; 0.05) were observed between the Assurance GDS for Salmonella and the Reference culture methods for any inoculation level of any food type or naturally contaminated food, except for pasta, for which the Assurance GDS method had a higher number of confirmed test portions for Salmonella compared to the Reference method.

Method Extension Study to Validate Applicability of AOAC Official Method 996.14 Assurance® Polyclonal Enzyme Immunoassay for Detection of Listeria monocytogenes and Related Listeria spp. from Environmental Surfaces: Collaborative Study

Test portions from 3 environmental surface types, representative of typical surfaces found in a food production facility, were analyzed by the Assurance®Listeria Polyclonal Enzyme Immunoassay (EIA) and the U.S. Department of Agriculture/Food Safety and Inspection Service (USDA/FSIS) culture method for Listeria monocytogenes and related Listeria species. In all cases, naturally contaminated environmental test samples were collected from an actual food production facility by sponge or swab. Test samples from concrete surfaces were collected by both swab and sponge; sponge test samples were collected from rubber surfaces, and swabs were used to sample steel surfaces. Test portions from each surface type were simultaneously analyzed by both methods. A total of 23 collaborators, representing government agencies, as well as private industry in both the United States and Canada, participated in the study. During this study, a total of 550 test portions and controls was analyzed and confirmed, of which 207 were positive and 336 were negative by both methods. Six test portions were positive by culture, but negative by the EIA. Three test portions were negative by culture, but positive by the EIA. Two test portions were negative by EIA and by culture, but confirmed positive when EIA enrichment broths were subcultured to selective agars. The data reported here indicate that the Assurance®Listeria EIA method and the USDA/FSIS culture method are statistically equivalent for detection of L. monocytogenes and related Listeria species from environmental surfaces taken by sponges or swabs.

Method Extension Study to Validate Applicability of AOAC Official Method 997.03 Visual Immunoprecipitate Assay (VIP®) for Listeria monocytogenes and Related Listeria spp. from Environmental Surfaces: Collaborative Study

Test portions from 3 environmental surface types, representative of typical surfaces found in a food production facility, were analyzed by the Visual Immunoprecipitate assay (VIP®) and the U.S. Department of Agriculture/Food Safety and Inspection Service (USDA/FSIS) culture method for Listeria monocytogenes and related Listeria species. In all cases, naturally contaminated environmental test samples were collected from an actual food production facility by sponge or swab. Test samples from concrete surfaces were collected by both swab and sponge; sponge test samples were collected from rubber surfaces, and swabs were used to sample steel surfaces. Test portions from each surface type were simultaneously analyzed by both methods. A total of 27 laboratories, representing government agencies as well as private industry in both the United States and Canada, participated in the study. During this study, a total of 615 test portions and controls was analyzed and confirmed, of which 227 were positive and 378 were negative by both methods. Nine test portions were positive by culture, but negative by the VIP. Five test portions were negative by culture, but positive by the VIP. Four test portions were negative by VIP and by culture, but confirmed positive when VIP enrichment broths were subcultured to selective agars. The data reported here indicate that the VIP method and the USDA/FSIS culture method are statistically equivalent for detection of L. monocytogenes and related Listeria species from environmental surfaces taken by sponges or swabs.

Equivalence of Assurance® Gold Enzyme Immunoassay for Visual or Instrumental Detection of Motile and Nonmotile Salmonella in All Foods to AOAC Culture Method: Collaborative Study

Six foods representative of a wide variety of processed, dried powder processed, and raw food types were analyzed by the Assurance® Gold Salmonella Enzyme Immunoassay (EIA) and AOAC INTERNATIONAL culture method. Paired samples of each food type were simultaneously analyzed; one sample by the Assurance method and one by the AOAC culture method. The results for Assurance method were read visually and instrumentally with a microplate reader. A total of 24 laboratories representing federal government agencies and private industry, in the United States and Canada, participated in this collaborative study. Food types were inoculated with species of Salmonella with the exception of raw ground chicken, which was naturally contaminated. No statistical differences (p &lt; 0.05) were observed between Assurance Gold Salmonella EIA with either visual or instrumental interpretation and the AOAC culture method for any inoculation level of any food type or naturally contaminated food. The Assurance visual and instrumental options of reading sample reactions produced the same results for 1277 of the 1296 sample and controls analyzed.

Histological stroke clot analysis after thrombectomy: Technical aspects and recommendations

The recent advent of endovascular procedures has created the unique opportunity to collect and analyze thrombi removed from cerebral arteries, instigating a novel subfield in stroke research. Insights into thrombus characteristics and composition could play an important role in ongoing efforts to improve acute ischemic stroke therapy. An increasing number of centers are collecting stroke thrombi. This paper aims at providing guiding information on thrombus handling, procedures, and analysis in order to facilitate and standardize this emerging research field.

Asbestos in commercial indian talc

Background

Easily available commercial Indian talc products widely used in Southeast Asia were examined for the presence of asbestos. Asbestos in talc products carry all risks of asbestos‐related disease.

Methods

Using polarizing light microscopy, transmission electron microscopy (TEM), electron diffraction, and X‐ray analysis, multiple over‐the‐counter Indian talc products were examined for the presence of asbestos.

Results

Results In an initial group of five Indian talc products, one was found to contain tremolite asbestos. The second group of eight products was tested and six of eight contained tremolite asbestos as well. No other regulated amphibole was found.

Conclusion

Large quantities of body talc products containing asbestos are used throughout Southeast Asia and are likely to pose a public health risk for asbestos‐related diseases, especially for the cancers related to asbestos exposure. The country of origin in which the talc examined was sourced for production is unknown to the authors, and further investigation to measure associated public health risk is needed.

Spatial variation in allometric growth of invasive lionfish has management implications

Lionfish (Pterois volitans/miles) are an invasive species in the Western Atlantic and the Caribbean. Improving management of invasive lionfish populations requires accurate total biomass estimates, which depend on accurate estimates of allometric growth; sedentary species like lionfish often exhibit high levels of spatial variation in life history characteristics. We reviewed 17 published length-weight relationships for lionfish taken throughout their invasive range and found regional differences that led to significant misestimates when calculating weight from length observations. The spatial pattern we observed is consistent with findings from other studies focused on genetics or length-at-age. Here, the use of ex situ parameter values resulted in total biomass estimates between 76.2% and 140% of true observed biomass, and up to a threefold under- or overestimation of total weight for an individual organism. These findings can have implications for management in terms of predicting effects on local ecosystems, evaluating the effectiveness of removal programs, or estimating biomass available for harvest.

Abstract WP95: Microct Data Can Distinguish Between in vitro Clot Types of Different Composition

Introduction: Several clinical studies have demonstrated that thrombectomy leads to improved clinical outcome and extends the treatment window for patients with acute ischemic stroke. This has motivated an expansion of the arsenal of available thrombectomy devices and an increased interest in image-guided patient selection and treatment. In vitro and in vivo studies have shown that the choice of thrombectomy device may be optimized according to the composition of the occluding clot. Baseline imaging may, therefore, guide the thrombectomy device choice, provided that the composition of the clot can be determined by imaging. Due to the low soft tissue contrast of CT images, the extraction of image parameters may, however, be confounded by pooling of blood around the occlusion.

Hypothesis: MicroCT images can be used to verify the x-ray density of the extracted clots in an unambiguous manner. These images may eventually be correlated to clinical baseline imaging to determine whether the x-ray density extracted from clinical images is representative of the clot or confounded by the pooling of blood around the occlusion.

Methods: In this pilot study, we investigated whether the x-ray density, as measured with a microCT (Qunatum GX; Perkin Elmer), could be used to distinguish between clot analogs made from whole blood (n=1) and clots of blood constituents mixed to produce ratios of 95% : 5% (n=1) and 5% : 95% red blood cells : fibrin (n=1). After imaging, the compositions of the clots were histologically verified by H&E staining.

Results: MicroCT data could be used to distinguish between red blood cell rich, whole blood and fibrinous clots with area-under-curve of receiver operating curves ranging between 0.64 and 0.82. The compositions of the red blood cell rich, the whole blood and the fibrinous clot were verified to contain 94% red blood cells and 6% fibrin, 70% red blood cells and 30 % fibrin, and 97% fibrin and 3% white blood cells respectively.

Conclusions: X-ray density—as measured on a microCT— can be used to infer the composition of blood clots. Further studies will be performed to determine whether the x-ray density of patient-derived clots, as measured with the microCT, is representative of the appearance of the clots on clinical baseline imaging.

A user-friendly tool to evaluate the effectiveness of no-take marine reserves

Marine reserves are implemented to achieve a variety of objectives, but are seldom rigorously evaluated to determine whether those objectives are met. In the rare cases when evaluations do take place, they typically focus on ecological indicators and ignore other relevant objectives such as socioeconomics and governance. And regardless of the objectives, the diversity of locations, monitoring protocols, and analysis approaches hinder the ability to compare results across case studies. Moreover, analysis and evaluation of reserves is generally conducted by outside researchers, not the reserve managers or users, plausibly thereby hindering effective local management and rapid response to change. We present a framework and tool, called "MAREA", to overcome these challenges. Its purpose is to evaluate the extent to which any given reserve has achieved its stated objectives. MAREA provides specific guidance on data collection and formatting, and then conducts rigorous causal inference analysis based on data input by the user, providing real-time outputs about the effectiveness of the reserve. MAREA's ease of use, standardization of state-of-the-art inference methods, and ability to analyze marine reserve effectiveness across ecological, socioeconomic, and governance objectives could dramatically further our understanding and support of effective marine reserve management.