How does the antimicrobial stewardship provider role affect prospective audit and feedback acceptance for restricted antibiotics in a Canadian tertiary-care center?

Of 731 restricted antimicrobial prescriptions subject to antimicrobial stewardship program (ASP) prospective audit and feedback (PAF) over a 3-year period, 598 PAF recommendations (82%) were fully accepted. Physician auditors had an increased odds of PAF recommendation acceptance, reinforcing the complementary role of the ASP physician in the multidisciplinary ASP team.

A novel Doppler backscattering (DBS) system to simultaneously measure radio frequency plasma fluctuations and low frequency turbulence

A novel quadrature Doppler Backscattering (DBS) system has been developed and optimized for the E-band (60-90 GHz) frequency range using either O-mode or X-mode polarization in DIII-D plasmas. In general, DBS measures the amplitude of density fluctuations and their velocity in the lab frame. The system can simultaneously monitor both low-frequency turbulence (f < 10 MHz) and radiofrequency plasma density fluctuations over a selectable frequency range (20-500 MHz). Detection of high-frequency fluctuations has been demonstrated for low harmonics of the ion cyclotron frequency (e.g., 2fci ∼ 23 MHz) and externally driven high-frequency helicon waves (f = 476 MHz) using an adjustable frequency down conversion system. Importantly, this extends the application of DBS to a high-frequency spectral domain while maintaining important turbulence and flow measurement capabilities. This unique system has low phase noise, good temporal resolution (sub-millisecond), and excellent wavenumber coverage (kθ ∼ 1-20 cm-1 and kr ≲ 30 cm-1). As a demonstration, localized internal DIII-D plasma measurements are presented from turbulence (f ≤ 5 MHz), Alfvenic waves (f ∼ 6.5 MHz), ion cyclotron waves (f ≥ 20 MHz), as well as fluctuations around 476 MHz driven by an external high-power 476 MHz helicon wave antenna. In the future, helicon measurements will be used to validate GENRAY and AORSA modeling tools for prediction of helicon wave propagation, absorption, and current drive location for the newly installed helicon current drive system on DIII-D.

Evaluation of the Abel inversion integral in O-mode plasma reflectometry using Chebyshev-Gauss quadrature

The Abel transform is often used to reconstruct plasma density profiles from O-Mode polarized reflectometry diagnostics. However, standard numerical trapezoidal evaluation of the Abel inversion integral can be computationally expensive for a large number of evaluation points, and an endpoint singularity exists on the upper-bound of the integral, which can result in an increased error. In this work, Chebyshev-Gauss quadrature is introduced as a new method to evaluate the Abel inversion integral for the problem of O-Mode plasma reflectometry. The method does not require numerical evaluation of an integral singularity and is shown to have similar accuracy compared to existing methods while being computationally efficient.

Efficacy and safety of antimicrobial stewardship prospective audit and feedback in patients hospitalised with COVID-19 (COVASP): a pragmatic, cluster-randomised, non-inferiority trial

BACKGROUND

The COVID-19 pandemic has been associated with increased antimicrobial use despite low rates of bacterial co-infection. Prospective audit and feedback is recommended to optimise antibiotic prescribing, but high-quality evidence supporting its use for COVID-19 is absent. We aimed to study the efficacy and safety of prospective audit and feedback in patients admitted to hospital for the treatment of COVID-19.

METHODS

COVASP was a prospective, pragmatic, non-inferiority, small-unit, cluster-randomised trial comparing prospective audit and feedback plus standard of care with standard of care alone in adults admitted to three hospitals in Edmonton, AB, Canada, with COVID-19 pneumonia. All patients aged at least 18 years who were admitted from the community to a designated study bed with microbiologically confirmed SARS-CoV-2 infection in the preceding 14 days were included if they had an oxygen saturation of 94% or lower on room air, required supplemental oxygen, or had chest-imaging findings compatible with COVID-19 pneumonia. Patients were excluded if they were transferred in from another acute care centre, enrolled in another clinical trial that involved antibiotic therapy, expected to progress to palliative care or death within 48 h of hospital admission, or managed by any member of the research team within 30 days of enrolment. COVID-19 unit and critical care unit beds were stratified and randomly assigned (1:1) to the prospective audit and feedback plus standard of care group or the standard of care group. Patients were masked to their bed assignment but the attending physician and study team were not. The primary outcome was clinical status on postadmission day 15, measured using a seven-point ordinal scale. We used a non-inferiority margin of 0·5. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, NCT04896866, and is now closed.

FINDINGS

Between March 1 and Oct 29, 2021, 1411 patients were screened and 886 were enrolled: 457 into the prospective audit and feedback plus standard of care group, of whom 429 completed the study, and 429 into the standard of care group, of whom 404 completed the study. Baseline characteristics were similar for both groups, with an overall mean age of 56·7 years (SD 17·3) and a median baseline ordinal scale of 4·0 (IQR 4·0-5·0). 301 audit and feedback events were recorded in the intervention group and 215 recommendations were made, of which 181 (84%) were accepted. Despite lower antibiotic use in the intervention group than in the control group (length of therapy 364·9 vs 384·2 days per 1000 patient days), clinical status at postadmission day 15 was non-inferior (median ordinal score 2·0 [IQR 2·0-3·0] vs 2·0 [IQR 2·0-4·0]; p=0·37, Mann-Whitney U test). Neutropenia was uncommon in both the intervention group (13 [3%] of 420 patients) and the control group (20 [5%] of 396 patients), and acute kidney injury occurred at a similar rate in both groups (74 [18%] of 421 patients in the intervention group and 76 [19%] of 399 patients in the control group). No intervention-related deaths were recorded.

INTERPRETATION

This cluster-randomised clinical trial shows that prospective audit and feedback is safe and effective in optimising and reducing antibiotic use in adults admitted to hospital with COVID-19. Despite many competing priorities during the COVID-19 pandemic, antimicrobial stewardship should remain a priority to mitigate the overuse of antibiotics in this population.

FUNDING

None.

1784. Appropriateness of Intravenous Vancomycin in a Canadian Acute Care Hospital

Background

Intravenous (IV) vancomycin is a commonly prescribed antimicrobial. However, there is limited literature assessing IV vancomycin appropriateness. The objective of the study was to assess the appropriateness of IV vancomycin prescriptions in a Canadian acute care hospital.

Methods

Prospective audit and feedback (PAF) was conducted on all new IV vancomycin prescriptions in hospitalized adults (age ≥ 18 years) at the University of Alberta Hospital from January 17 to February 11, 2022. Appropriateness was assessed against institutional prescribing guidelines (Bugs & Drugs® and Alberta Health Services Formulary Prescribing Guidelines). Verbal and written feedback were provided to the attending teams.

Results

A total of 109 prescriptions were audited. Median age was 57 (IQR 43-72) years and 42% were female. 65 (60%) were admitted to Medicine, 18 (17%) to Surgery, and 26 (24%) to Intensive Care units. MRSA colonization was present in 32 (29%) patients, β-lactam allergy recorded in 21 (19%), and acute kidney injury (AKI) in 21 (19%). Infectious Diseases consultation (IDC) occurred in 29 (27%). The top indications were skin and soft tissue, pulmonary, and bloodstream infections (Table 1); 70% of prescriptions were empiric in nature.

Overall, 43 (39%) prescriptions were assessed to be suboptimal. Antimicrobial Stewardship program (ASP) recommendations were made in 56 prescriptions, totaling 63 unique recommendations. Vancomycin was recommended to be discontinued in 24 (43%) cases or changed to a different agent in 15 (27%). Regimen optimization (duration or frequency change) was recommended in 4 (7%). ASP recommended investigations in 8 cases and IDC in 12. Full or partial acceptance was achieved in 49 cases (88%).

IDC was associated with greater appropriateness (83% vs 53%, p=0.004) as was MRSA colonization (75% vs 55%, p=0.047), but AKI was not (62% vs 60%, p=0.888). Adjusting for age, AKI, and MRSA colonization, IDC remained a significant predictor of vancomycin appropriateness (OR=4.27, [95%CI 1.44-12.70]; p=0.009).

Conclusion

IV vancomycin prescriptions were suboptimal in 39% of cases. IDC was associated with increased appropriateness. This pilot informs the need for antimicrobial stewardship intervention and the importance of IDC at our center.

Disclosures

Dima Kabbani, MD, MSc, AVIR Pharma: Grant/Research Support|AVIR Pharma: Honoraria|GSK: Honoraria|Merck: Grant/Research Support.

872. Voriconazole Therapeutic Drug Monitoring (TDM): How Common is Autoinduction?

Background

Therapeutic drug monitor (TDM) guided optimized dosing of Voriconazole allows optimal drug exposure in the management of mold infection (MI). In addition to already known nuances in pharmacokinetics such as CYP2C19 genetic polymorphism and the role of drug interactions both necessitating TDM, case reports have suggested that auto-induction may occur after initially achieving a therapeutic level. We assessed whether the levels of Voriconazole can change over time and become subtherapeutic due to auto-induction.

Methods

We prospectively enrolled, adults ≥ 18 y.o of age, on Voriconazole for the treatment of MI at the University Of Alberta Hospital. After achieving an initial therapeutic margin, (1–5.5mg/l), we monitored Voriconazole levels twice a month, using high-performance liquid chromatography, until discontinuation or at 12 weeks of therapy. We calculated the incidence of Voriconazole sub-therapeutic concentrations (auto-induction) defined as drop of Voriconazole level below one, with previous concentrations between the therapeutic margins of 1–5.5 mg/L. Adjustment of Voriconazole dosing in case of auto-induction was at the discretion of the treating physician. The excess Voriconazole dose adjustment was calculated in patients where dosing was increased.

Results

Between January 2021 and April 2022, we enrolled 12 patients. Median age (IQR) was 62 (52–73), and 25 % were female. Patient characteristics are in table 1. Auto-induction was observed in 6/10 (60%) who completed 12 weeks follow up blood work. Median time to auto-induction was of 46 days (39–55). Voriconazole dosing was increased in 4/6 patients with auto-induction. Of the four patients with dose adjustment, the cumulative Voriconazole dose was 13% higher than expected, which correspond to 5,300 mg excess Voriconazole per patient to maintain therapeutic levels.

Conclusion

Auto-induction is common in patients treated with Voriconazole. Future studies are needed to assess if undetected auto-induction affects outcomes.

Funding: AVIR Pharma.

Disclosures

Carlos Cervera, Associate Professor, Astra-Zeneca: Advisor/Consultant|AVIR Pharma: Grant/Research Support|AVIR Pharma: Honoraria|Lilly: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Merck: Honoraria|Sunovion: Advisor/Consultant|Takeda: Advisor/Consultant|Takeda: Honoraria|VerityPharma: Advisor/Consultant Dima Kabbani, MD, MSc, AVIR Pharma: Grant/Research Support|AVIR Pharma: Honoraria|GSK: Honoraria|Merck: Grant/Research Support.

Efficacy and safety of antimicrobial stewardship prospective audit and feedback in patients hospitalized with COVID-19: A protocol for a pragmatic clinical trial

Background

The use of broad-spectrum antibiotics is widespread in patients with COVID-19 despite a low prevalence of bacterial co-infection, raising concerns for the accelerated development of antimicrobial resistance. Antimicrobial stewardship (AMS) is vital but there are limited randomized clinical trial data supporting AMS interventions such as prospective audit and feedback (PAF). High quality data to demonstrate safety and efficacy of AMS PAF in hospitalized COVID-19 patients are needed.

Methods and design

This is a prospective, multi-center, non-inferiority, pragmatic randomized clinical trial evaluating AMS PAF intervention plus standard of care (SOC) versus SOC alone. We include patients with microbiologically confirmed SARS-CoV-2 infection requiring hospital admission for severe COVID-19 pneumonia. Eligible ward beds and critical care unit beds will be randomized prior to study commencement at each participating site by computer-generated allocation sequence stratified by intensive care unit versus conventional ward in a 1:1 fashion. PAF intervention consists of real time review of antibacterial prescriptions and immediate written and verbal feedback to attending teams, performed by site-based AMS teams comprised of an AMS pharmacist and physician. The primary outcome is clinical status at post-admission day 15 measured using a 7-point ordinal scale. Patients will be followed for secondary outcomes out to 30 days. A total of 530 patients are needed to show a statistically significant non-inferiority, with 80% power and 2.5% one-sided alpha assuming standard deviation of 2 and the non-inferiority margin of 0.5.

Discussion

This study protocol presents a pragmatic clinical trial design with small unit cluster randomization for AMS intervention in hospitalized COVID-19 that will provide high-level evidence and may be adopted in other clinical situations.

Trial registration

This study is being performed at the University of Alberta and is registered at ClinicalTrials.gov (NCT04896866) on May 17, 2021.

117. How Does Antimicrobial Stewardship Provider Role Affect Prospective Audit and Feedback Acceptance by the Attending Physician?

Background

Antimicrobial stewardship (AMS) teams are commonly multidisciplinary. The effect of AMS provider role on prospective audit and feedback (PAF) acceptance has previously been investigated with mixed results. PAF of restricted antimicrobials (carbapenems, linezolid, daptomycin, and tigecycline) in adult inpatients at our large Canadian academic centre has been performed since 2018. Actionable feedback is communicated via chart note plus one of a phone call, direct message, or in-person discussion with the most responsible physician of the attending team in order to optimize the prescription if deemed necessary. The objective of this study was to assess the effect of AMS provider role on PAF acceptance.

Methods

A 3 year retrospective review of all PAF events was undertaken. All audited prescriptions were included. Logistic regression was used to determine odds ratios for acceptance for individual AMS provider roles of pharmacist, physician, and supervised post-graduate physician trainee.

Results

Out of 1896 prescriptions audited, actionable feedback was provided to the most responsible physician in 731 (39%) cases. 677/731 (93%) of audited antibiotics were carbapenems. The overall acceptance rate was 82% (598/731). Acceptance rate and odds of acceptance based on AMS provider role were as follows: pharmacist alone 171/208 (82%), OR 1.04, 95% CI 0.70-1.59, physician alone 141/160 (88%), OR 1.85, 95% CI 1.12-3.20, pharmacist-physician duo 211/268 (79%), OR 0.73, 95% CI 0.50-1.07, and supervised post-graduate physician trainee 75/95 (79%), OR 0.81, 95% CI 0.48-1.41.

Conclusion

The overall acceptance rate was high. There was a higher odds of acceptance if an AMS physician was providing PAF alone, highlighting the importance of physician involvement.

Disclosures

Dima Kabbani, MD, AVIR Pharma (Grant/Research Support, Other Financial or Material Support, Speaker)Edesa Biotech (Scientific Research Study Investigator)Merck (Scientific Research Study Investigator)

Inorganic nitrate attenuates endothelial dysfunction consequent to systemic inflammation

Introduction

Chronic cardiovascular diseases are characterised by low-grade systemic inflammation and attenuated nitric oxide (NO) bioavailability resulting in endothelial dysfunction. Inorganic nitrate augments NO bioavailability and improves markers of vascular dysfunction in patients with cardiovascular risk factors. However, the exact mechanism of this effect is uncertain.

Purpose

To determine whether inorganic nitrate supplementation alters systemic inflammation-induced endothelial dysfunction.

Methods

62 healthy male volunteers were randomised 1:1 to receive ∼8–10 mmol of dietary inorganic nitrate in beetroot juice or nitrate-free beetroot juice (placebo) once daily for 6 days. Measures of brachial artery flow-mediated dilatation (FMD), brachial blood pressure (BP), pulse wave analysis and carotid-femoral pulse wave velocity (PWV) by Vicorder were taken prior to and at 8 hours after a typhoid vaccine (to induce mild systemic inflammation). Plasma, urine and saliva samples were also collected. Clinicaltrials.gov: NCT02715635.

Results

Baseline characteristics were similar between the two groups. Inorganic nitrate significantly elevated plasma nitrite (placebo = Δ0.02±0.5 μM, inorganic nitrate = Δ0.63±1.2 μM; p=0.01) and nitrate levels (p&lt;0.0001) compared to placebo. There were significant increases in urine nitrite (p&lt;0.0001) and nitrate (p&lt;0.0001) in addition to salivary nitrite (p&lt;0.0001) and nitrate (p&lt;0.0001) compared to placebo. After 8 hours, typhoid vaccine induced an increase in circulating white cells (placebo = Δ3.34±3.37x109/L, inorganic nitrate = Δ2.9±2.78x109/L; p=0.58) that was similar in in both arms. However, there was a significant reduction in the FMD response in the placebo group at 8-hours post vaccine; an effect that was absent in volunteers treated with inorganic nitrate (placebo = Δ−1.33±1.53%, inorganic nitrate = Δ−0.07±1.84%, p=0.005). Importantly, there were no statistically significant differences in baseline vessel diameter (p=0.78), time to peak diameter in response to flow (p=0.87) and peak shear rate (p=0.57) between the groups. When comparing change from baseline to 8 hours after the vaccine, there were no significant differences in brachial systolic BP (p=0.12), central systolic BP (p=0.12) and PWV (p=0.60) between groups, but a significant reduction in brachial diastolic BP in the inorganic nitrate group (p=0.048).

Conclusions

Inflammation-induced endothelial dysfunction was prevented in those receiving dietary inorganic nitrate suggesting that elevating circulating nitrite and delivering NO to the blood vessel wall, through dietary approaches may offer potential therapeutic benefit in those cardiovascular diseases which typically exhibit low grade inflammation and deficiencies in bioavailable NO.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): British Heart Foundation

Inorganic nitrate attenuates the systemic inflammatory response in typhoid vaccine-induced endothelial dysfunction in healthy volunteers

Background

Inflammatory responses underlie the development of endothelial dysfunction in CVD, however, therapeutics that might target this pathway have not been forthcoming. A key pathogenic mechanism mediating endothelial dysfunction is a reduction in bioavailable (eNOS-derived) nitric oxide (NO). Activation of the non-canonical pathway for in-vivo NO generation might offer an approach to improve NO levels and recover vascular function in pre-clinical models of CVD. Whether this might occur in humans is unknown.

Purpose

We hypothesize that consumption of inorganic nitrate will lead to increases in bioavailable NO and thus attenuate the inflammatory pathways leading to typhoid vaccine-induced endothelial dysfunction in healthy volunteers.

Methods

Healthy male volunteers were recruited (n=78) and randomized to receive either beetroot juice containing 8–10mmol nitrate or placebo (nitrate-deplete) juice once daily for 6 days. Participants underwent serial measurements of BP, FMD and GTN-induced brachial artery dilatation, and haematology and biochemistry, before and after typhoid vaccination. Blood, urine and saliva nitrite and nitrate were quantified using ozone chemiluminescence, and leukocyte flow cytometry analysis was conducted.

Results

8-hours post-vaccine endothelial function was depressed in placebo-treated volunteers, however this was prevented in nitrate-treated volunteers. This dysfunction was due to impaired endothelial function since responses to GTN were unaffected either by vaccination or dietary intervention (p=0.981). Dietary nitrate resulted in an increase in plasma (p&lt;0.0001), urine (p=0.0006) and saliva (p&lt;0.0001) nitrate, and urine (p=0.0354) and saliva (p&lt;0.0001) nitrite levels. There was a reduction in the proportions of CD14++/CD16+intermediate monocytes in nitrate-treated participants after vaccine (p=0.016, change from baseline between groups). In the nitrate-treated group, less CD14++/CD16+ intermediate monocyte CD62L expression was identified post-vaccine (p=0.0122), compared to placebo, with no difference in soluble plasma CD62L between groups (p=0.875). CD11b median fluorescence intensity was increased in CD3+/CD4+ T-lymphocytes in nitrate-treated volunteers (p=0.0095).

Conclusions

Dietary nitrate reduced BP, as previously shown, indicating efficacy of the intervention. Importantly, we also now show for the first time that inorganic nitrate suppresses the systemic inflammatory response, specifically by reducing the numbers and activation state of CD14++/CD16+ intermediate monocytes. Furthermore, an increased expression of CD3+/CD4+ T-cell CD11b and preserved FMD in healthy volunteers treated with nitrate, suggests an anti-inflammatory phenotype, induced by the intervention, leading to improved endothelial function. Inorganic dietary nitrate modulates endothelial function through the attenuation of inflammatory responses and may be of potential therapeutic benefit in patients with established CAD.

Funding Acknowledgement

Type of funding sources: None.

Prospective case-control study of cardiovascular abnormalities six months following mild COVID-19 in healthcare workers

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Barts Charity UCLH Charity

OnBehalf

COVIDsortium

Background

Recent CMR studies have reported cardiac abnormalities after COVID-19 are common, even after mild, non-hospitalised illness with evidence of ongoing myocardial inflammation.  Such a prevalence of chronic myocarditis after mild disease has prompted societal concerns in diverse domains, and suggests that screening should be considered post COVID-19, even in asymptomatic individuals.  Cardiovascular magnetic resonance (CMR) has proven utility for diagnosis in patients with COVID-19 infection and elevated troponin from unclear causes by measuring cardiac structure, function, myocardial scar (late gadolinium enhancement) and oedema (T1 and T2 mapping).

Objectives

We aimed to determine the prevalence and extent of late cardiac and cardiovascular sequelae after mild non-hospitalised SARS-CoV-2 infection.

Methods

Participants were recruited from COVIDsortium, a three-hospital prospective study of 731 healthcare workers who underwent first wave weekly symptom, PCR and serology assessment over 4 months, with seroconversion in 21.5% (n = 157). At 6 months post infection, 74 seropositive and 75 age-, sex-, ethnicity-matched seronegative controls were recruited for cardiovascular phenotyping (comprehensive phantom-calibrated Cardiovascular Magnetic Resonance and blood biomarkers). Analysis was blinded, using objective AI analytics where available.

Results

149 subjects (mean age 37 years, range 18-63, 58% female) were recruited. Seropositive infections had been mild with case definition/non-case definition/asymptomatic disease in 45(61%), 18(24%) and 11(15%) with one person hospitalised (for 2 days). Between seropositive and seronegative groups, there were no differences in cardiac structure (left ventricular volumes, mass; atrial area), function (ejection fraction, global longitudinal shortening, aortic distensibility), tissue characterisation (T1, T2, ECV mapping, late gadolinium enhancement) or biomarkers (troponin, NT-proBNP).  With abnormal defined by the 75 seronegatives (2 standard deviations from mean, e.g. EF &lt; 54%, septal T1 &gt; 1072ms, septal T2 &gt; 52.4ms), individuals had abnormalities including reduced EF (n = 2, minimum 50%), T1 elevation (n = 6), T2 elevation (n = 9), LGE (n = 13, median 1%, max 5% of myocardium), biomarker elevation (borderline troponin elevation in 4; all NT-proBNP normal). These were distributed equally between seropositive and seronegative individuals.

Conclusions

Cardiovascular abnormalities are no more common in seropositive vs seronegative otherwise healthy, workforce representative individuals 6 months post mild SARS-CoV-2 infection.  Our study provides societal reassurance for the cardiovascular health of working-aged individuals with convalescence from mild SARS-CoV-2. Screening asymptomatic individuals following mild diseases is not indicated.

The Voronoi theory of the normal liver lobular architecture and its applicability in hepatic zonation

The precise characterization of the lobular architecture of the liver has been subject of investigation since the earliest historical publications, but an accurate model to describe the hepatic lobular microanatomy is yet to be proposed. Our aim was to evaluate whether Voronoi diagrams can be used to describe the classic liver lobular architecture. We examined the histology of normal porcine and human livers and analyzed the geometric relationships of various microanatomic structures utilizing digital tools. The Voronoi diagram model described the organization of the hepatic classic lobules with overall accuracy nearly 90% based on known histologic landmarks. We have also designed a Voronoi-based algorithm of hepatic zonation, which also showed an overall zonal accuracy of nearly 90%. Therefore, we have presented evidence that Voronoi diagrams represent the basis of the two-dimensional organization of the normal liver and that this concept may have wide applicability in liver pathology and research.

Pneumocystis jirovecii: a review with a focus on prevention and treatment

Introduction: Pneumocystis jirovecii (PJ) is an opportunistic fungal pathogen that can cause severe pneumonia in immunocompromised hosts. Risk factors for Pneumocystis jirovecii pneumonia (PJP) include HIV, organ transplant, malignancy, certain inflammatory or rheumatologic conditions, and associated therapies and conditions that result in cell-mediated immune deficiency. Clinical signs of PJP are nonspecific and definitive diagnosis requires direct detection of the organism in lower respiratory secretions or tissue. First-line therapy for prophylaxis and treatment remains trimethoprim-sulfamethoxazole (TMP-SMX), though intolerance or allergy, and rarely treatment failure, may necessitate alternate therapeutics, such as dapsone, pentamidine, atovaquone, clindamycin, primaquine and most recently, echinocandins as adjunctive therapy. In people living with HIV (PLWH), adjunctive corticosteroid use in treatment has shown a mortality benefit.Areas covered: This review article covers the epidemiology, pathophysiology, diagnosis, microbiology, prophylaxis indications, prophylactic therapies, and treatments.Expert opinion: TMP-SMX has been first-line therapy for treating and preventing pneumocystis for decades. However, its adverse effects are not uncommon, particularly during treatment. Second-line therapies may be better tolerated, but often sacrifice efficacy. Echinocandins show some promise for new combination therapies; however, further studies are needed to define optimal antimicrobial therapy for PJP as well as the role of corticosteroids in those without HIV.

Impact of obesity on myocardial microvasculature assessed using fully-automated inline myocardial perfusion mapping CMR

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Guy"s and St Thomas" Charity University College London Hospitals Biomedical Research Centre

Background

Obesity and cardiovascular disease are associated, but the relationship is poorly understood. Myocardial perfusion, metabolic derangement and lipotoxicity appear adversely associated in many scenarios (myocardial injury, diastolic dysfunction, diabetes). Altered perfusion (by PET) predicts outcome, and it is hypothesised that perfusion derangement is part of causality for cardiac disease and adverse outcomes.

Purpose

To assess the presence and pattern of myocardial microvascular dysfunction in patients with obesity (scheduled for bariatric surgery) using stress quantitative perfusion mapping.

Methods

38 subjects with obesity planned to undergo bariatric surgery and 38 age and sex matched healthy volunteers (no diabetes, no hypertension) underwent anthropometry, biochemistry and CMR at 1.5T (Siemens) with cine imaging, stress (adenosine 140-210 mcg/kg/min) and rest fully-automated quantitative perfusion mapping. 

Results

Bariatric patients had a higher BMI (44 ± 6.4 vs 26.5 ± 4kg/m2 p = 0.001); 58%(22) were diabetic and 58%(22) had hypertension. Bariatric patients had higher absolute but lower indexed end-diastolic volumes, and overall higher ejection fractions (+5%) (see Table). Rest myocardial blood flow (MBF) in bariatric patients was the same (1.00 ± 0.3 vs 0.88 ± 0.24 p = 0.052), but stress perfusion results were significantly lower both for stress MBF (2.35 ± 0.69 vs 2.93 ± 0.76ml/g/min p = 0.001) and myocardial perfusion reserve (MPR 2.48 ± 0.82 vs 3.4 ± 0.81ml/g/min p = 0.0001).  Although this was transmural, the endocardial stress MBF was particularly negatively affected in the bariatric cohort compared to controls (endocardial MBF 2.16 ± 0.65 vs 2.82 ± 0.73ml/g/min, p = 0.0001 vs epicardial MBF: 2.52 ± 0.76 vs 3.06 ± 0.79 p = 0.003), meaning there was an increased endo-epicardial stress MBF gradient in bariatric patients (0.87 ± 0.12 vs 0.92 ± 0.07 p = 0.03).

Conclusion

Compared to healthy controls, patients with obesity have abnormal myocardial stress perfusion with reduced global perfusion, perfusion reserve and an increased transmyocardial perfusion gradient.

Table - myocardial perfusion parameters Category Bariatric patients n = 38 Controls n = 38 p value Age (years) 48 ± 11 45 ± 13 0.25 n male (%) 12 (32%) 10 (36%) 0.32 LVEDV (ml) 168 ± 37 149 ± 31 0.017 LVEDVi (ml/m2) 70.4 ± 12.3 78.8 ± 12.1 0.004 LV Mass (g) 116 ± 31 99 ± 28 0.019 EF (%) 70 ± 8 65 ± 5 0.002 LVEDV - left ventricular end-diastolic volume, EF - ejection fraction

The myocardial phenotype of Fabry disease pre-hypertrophy and pre-detectable storage

Background

Cardiac involvement in Fabry Disease (FD) occurs prior to left ventricular hypertrophy (LVH) and is characterized by low myocardial native T1 with storage reflected by cardiovascular magnetic resonance (CMR) and ECG changes.

Objectives

We hypothesize that a pre-storage myocardial phenotype might occur even earlier, prior to T1 lowering.

Methods

FD patients and age, sex and heart rate matched healthy controls underwent same-day ECG with advanced analysis and multiparametric CMR (cines, global longitudinal strain [GLS], T1 and T2 mapping, stress perfusion [myocardial blood flow, MBF] and late gadolinium enhancement [LGE]).

Results

114 Fabry patients (46±13 years, 61% female) and 76 controls (49±15 years, 50% female) were included. In pre-LVH FD (n=72, 63%), a low T1 (n=32/72, 44%) was associated with a constellation of ECG and functional abnormalities compared to normal T1 FD patients and controls. However, pre-LVH FD with normal T1 (n=40/72, 56%) also had abnormalities compared to controls: reduced GLS (−18±2 vs −20±2%, P&lt;0.001), microvascular changes (lower MBF 2.5±0.7 vs 3.0±0.8mL/g/min, P=0.028), subtle T2 elevation (50±4 vs 48±2ms, p=0.027) and limited LGE (%LGE 0.3±1.1 vs 0%, P=0.004). ECG abnormalities included shorter P wave duration (88±12 vs 94±15ms, P=0.010) and T wave peak time (Tonset–Tpeak; 104±28 vs 115±20ms, P=0.015), resulting in a more symmetric T wave with lower T wave time ratio (Tonset–Tpeak)/(Tpeak–Tend) (1.5±0.4 vs 1.8±0.4, P&lt;0.001) compared to controls.

Conclusions

FD has a measurable myocardial phenotype pre-LVH and pre-detectable myocyte storage with microvascular dysfunction, subtly impaired GLS and altered atrial depolarization and ventricular repolarization intervals.

Proposed stages of cardiac involvement

Funding Acknowledgement

Type of funding source: None

Abstract 4241: Regorafenib and nivolumab or pembrolizumab combination and ctDNA response assessment in refractory colorectal cancer

Introduction: Patients with microsatellite stable (MSS) metastatic colorectal cancer (MCRC) are considered resistant to immunotherapy with PD-1 and PD-L1 inhibitors. However, a recent study of regorafenib and nivolumab (REGONIVO) reported high response rates and a median progression free survival (PFS) of more than 6 months (mo) in a cohort of 24 Japanese patients (pts) with MSS chemo-resistant MCRC.

Methods: We evaluated the outcome of advanced MSS MCRC pts who were treated on a compassionate basis with PD-1 inhibitors in combination with regorafenib 80 mg PO QD x 21 days every 28 days in a single US center. We report their response rate (RR), PFS, and overall survival (OS).

Results: 16 pts (15 males) were treated with a combination of regorafenib + PD-1 inhibitors and were evaluable for response. 14 pts received regorafenib + nivolumab (5 with prior anti-PD-1 treatment) and 2 pts received regorafenib + pembrolizumab (both following pembrolizumab treatment). No treatment-related G3 or above toxicities were attributed to the combination therapy. No objective responses were noted on treatment. 11 pts had progressive disease (PD) and 5 pts experienced stable disease (SD) as best response at 2 mo. The duration of SD was 4 mo in 2 pts (1 pt with prior anti-PD1 exposure), 6 mo in 1 pt (prior anti-PD1 exposure), 5 mo+ in 2 pt (1 with prior anti-PD1 exposure). When limiting the analysis to the 9 regorafenib and checkpoint-inhibitor naïve patients, 2 pts were noted to have SD (4 months and 5 mo+). ctDNA assays were evaluated at baseline and at 4 weeks of treatment in 11 patients. All 9 patients with a rise in ctDNA at 4 weeks had PD at the 2-mo imaging point. 2 patients with declining ctDNA at 4 weeks experienced SD for 4 mo 5 mo+, each. OS analysis remains immature as the median follow-up is only 5 mo.

Conclusions: Regorafenib and nivolumab combination was associated with modest clinical activity in patients with MSS chemotherapy-resistant MCRC. This US-based small retrospective trial is at odds with the Japanese REGONIVO trial. ctDNA may represent a powerful tool for predicting progression prior to radiographic staging.

Citation Format: Marwan Fakih, Dawnyel Chevalier, Janelle Saluja, Cecilia Lau, Chongkai Wang. Regorafenib and nivolumab or pembrolizumab combination and ctDNA response assessment in refractory colorectal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4241.

Regorafenib and Nivolumab or Pembrolizumab Combination and Circulating Tumor DNA Response Assessment in Refractory Microsatellite Stable Colorectal Cancer

BACKGROUND

Metastatic colorectal cancers (MCRCs) with microsatellite stability (MSS) are resistant to immunotherapy with programmed cell death protein 1 (PD-1) and programmed death-ligand 1 inhibitors. However, the addition of regorafenib to nivolumab was recently associated with a high response rate and a protracted progression-free survival in a small cohort of MSS Japanese patients with metastatic colorectal cancer.

MATERIALS AND METHODS

We evaluated the outcome of patients with MSS metastatic colorectal cancer who were treated on a compassionate basis with PD-1 inhibitors in combination with regorafenib in a single U.S. center.

RESULTS

A total of 18 patients were treated with a combination of regorafenib and PD-1 inhibitors. No treatment-related grade 3 or above toxicities were noted. Thirteen patients (69%) had progressive disease, and five patients (31%) experienced stable disease as best response. Four out of five stable diseases occurred in patients without liver metastases, whereas only 1 of 14 patients with history of liver metastases had a short disease stabilization. A rise in circulating tumor DNA (ctDNA) at the 4-week time pointuniversally predicted tumor progression at 2 months, whereas a decline was associated with radiographic disease stabilization.

CONCLUSIONS

Regorafenib and nivolumab combination was associated with modest clinical activity in patients with MSS chemotherapy-resistant metastatic colorectal cancer. Selection for patients without history of liver metastases may identify a cohort of patients with MSS colorectal cancer with a higher likelihood of benefit from this combination. ctDNA may represent a powerful tool for predicting early therapeutic efficacy of immunotherapy in the MSS colorectal cancer population.

IMPLICATIONS FOR PRACTICE

This study showed that the combination of regorafenib and nivolumab was associated with a modest clinical activity in patients with advanced microsatellite stability (MSS) metastatic colorectal cancer. This combination should be avoided in clinical practice, especially in patients with MSS colorectal cancer with liver metastases. Further investigation of regorafenib plus PD-1 inhibitors should be considered in MSS colorectal cancer without liver metastases.

Early detection of parenting stress in mothers of preterm infants during their first-year home

Background

Maternal stress following the birth of an infant is well acknowledged. It is particularly so when infants are born prematurely as their mothers cannot fully take on their parenting role until their infant(s) is discharged from neonatal intensive care units (NICUs). In this exploratory study, we examined whether these mothers’ parenting stress would lessen during their first-year reunification with their infant(s) as they settle into motherhood at home.

Methods

Two groups of mothers with infants born between 24- and 33-week gestational age were recruited. A group of 25 mothers were monitored at their infants’ 1-month corrected age (CA) and a second group of 24 mothers were monitored at their infants’ 12-month CA. Subjects completed the long form Parental Stress Index (PSI) ranking how stressful they perceive the individual subscales in the Child and Parent Domains of the self-reported questionnaire (PSI-3; Abidin; PAR Inc). The PSI theorizes that the stress mothers perceive is a resultant of their respective characteristics, interactions with their infant(s), family, and environment. Statistical analyses include descriptive statistics, χ² square analysis, and independent t-test.

Results

There was no significant difference in the levels of perceived stress in the PSI subscales between the two groups of mothers at 1- and 12-month CA. Scores for the majority of respondents fell within the 15th to 80th percentile (% ile) distribution of Abidin’s normative population, with some mothers falling below the 15th % ile.

Discussion/conclusion

The data collected suggest that: 1. the perceived stress experienced by mothers during their first-year reunited with their preterm infants is within the normal range observed in Abidin’s normative population. 2. As the PSI is a self-reported survey, care providers need to be aware that some mothers may downplay their stress responses. 3. With the ability to monitor individual participants, the PSI can be readily offered to mothers at their infants’ first year routine clinical visits to assist in the early identification of parenting issues that may threaten the development of a healthy mother-infant dyad. Early appropriate guidance and social support would help “at-risk” mothers develop more constructive parenting routines.

Seatbelt Sign as an Indication for Four-vessel Computed Tomography Angiogram of the Neck to Diagnose Blunt Carotid Artery and Other Cervical Vascular Injuries

Computed tomography angiography (CTA) of the neck has become the most common modality for diagnosing blunt carotid artery injury (BCAI). The protocol at our institution includes CTA on trauma patients with a seatbelt sign. The purpose of this study is to evaluate whether a solitary seatbelt sign is an indication for CTA of the neck to diagnose BCAI. We conducted a retrospective review of patients from 2000 to 2010 who received CTAs as a result of a seatbelt sign performed at our Level I trauma center. Four hundred eighteen patients received CTAs based on the presence of a seatbelt sign. Two hundred twenty-six had skeletal injuries, obvious soft tissue injuries, and/or positive findings on imaging, including 11 positive vascular findings with two BCAIs found. Patients with noncarotid vascular injuries on CTA had a higher Injury Severity Score than patients with solitary seatbelt signs (11.4 ± 7.6 vs 3.4 ± 4.2, P < 0.01). The correlation between seatbelt sign and positive finding on CTA was weak ( r = 0.007). Patients with vascular findings on CTA also had obvious hard/soft tissue injuries and/or positive findings on standard trauma imaging. This suggests that a protocol for CTA of the neck for patients with a seatbelt sign can be reserved for those with associated injuries on physical examination and/or findings on standard trauma imaging.

Symptom-based patient stratification in mental illness using clinical notes

Mental illnesses are highly heterogeneous with diagnoses based on symptoms that are generally qualitative, subjective, and documented in free text clinical notes rather than as structured data. Moreover, there exists significant variation in symptoms within diagnostic categories as well as substantial overlap in symptoms between diagnostic categories. These factors pose extra challenges for phenotyping patients with mental illness, a task that has proven challenging even for seemingly well characterized diseases. The ability to identify more homogeneous patient groups could both increase our ability to apply a precision medicine approach to psychiatric disorders and enable elucidation of underlying biological mechanism of pathology. We describe a novel approach to deep phenotyping in mental illness in which contextual term extraction is used to identify constellations of symptoms in a cohort of patients diagnosed with schizophrenia and related disorders. We applied topic modeling and dimensionality reduction to identify similar groups of patients and evaluate the resulting clusters through visualization and interrogation of clinically interpretable weighted features. Our findings show that patients diagnosed with schizophrenia may be meaningfully stratified using symptom-based clustering.

Complement component 5 does not interfere with physiological hemostasis but is essential for Escherichia coli-induced coagulation accompanied by Toll-like receptor 4

There is a close cross-talk between complement, Toll-like receptors (TLRs) and coagulation. The role of the central complement component 5 (C5) in physiological and pathophysiological hemostasis has not, however, been fully elucidated. This study examined the effects of C5 in normal hemostasis and in Escherichia coli-induced coagulation and tissue factor (TF) up-regulation. Fresh whole blood obtained from six healthy donors and one C5-deficient individual (C5D) was anti-coagulated with the thrombin inhibitor lepirudin. Blood was incubated with or without E. coli in the presence of the C5 inhibitor eculizumab, a blocking anti-CD14 monoclonal antibody (anti-CD14) or the TLR-4 inhibitor eritoran. C5D blood was reconstituted with purified human C5. TF mRNA was measured by quantitative polymerase chain reaction (qPCR) and monocyte TF and CD11b surface expression by flow cytometry. Prothrombin fragment 1+2 (PTF1·2) in plasma and microparticles exposing TF (TF-MP) was measured by enzyme-linked immunosorbent assay (ELISA). Coagulation kinetics were analyzed by rotational thromboelastometry and platelet function by PFA-200. Normal blood with eculizumab as well as C5D blood with or without reconstitution with C5 displayed completely normal biochemical hemostatic patterns. In contrast, E. coli-induced TF mRNA and TF-MP were significantly reduced by C5 inhibition. C5 inhibition combined with anti-CD14 or eritoran completely inhibited the E. coli-induced monocyte TF, TF-MP and plasma PTF1·2. Addition of C5a alone did not induce TF expression on monocytes. In conclusion, C5 showed no impact on physiological hemostasis, but substantially contributed to E. coli-induced procoagulant events, which were abolished by the combined inhibition of C5 and CD14 or TLR-4.

A spectroscopic electric field vector imaging diagnostic for electron cyclotron heating systems

An experimental measurement of the wave electric field vector provides important data that can be used to directly compare against 3D full-wave simulations. This direct comparison yields the fastest approach toward identifying missing physics in computational models and providing a high fidelity validation platform. In this paper, we present a diagnostic that is capable of imaging the Electron Cyclotron (EC) wave electric field vector by acquiring filtered images of polarized D _β spectral satellites. The diagnostic is designed to have a spatial and temporal resolution on the order of 100 μm and 100 μs, respectively. The diagnostic purpose is to provide experimental data for the direct validation of full-wave codes used to predict EC beam propagation and absorption and to provide real-time monitoring of EC waves.

Combination Doppler backscattering/cross-polarization scattering diagnostic for the C-2W field-reversed configuration

A versatile combination Doppler backscattering and Cross-Polarization Scattering (CPS) diagnostic for the C-2W beam-driven field-reversed configuration is described. This system is capable of measuring density fluctuations and perpendicular magnetic field fluctuations across a wide wavenumber range (2.5 ≤ k _θ ρ _s ≤ 50), with typical resolution Δk _θ/k _θ ≤ 0.4-0.8. Four tunable frequencies (26 GHz ≤ f ≤ 60 GHz corresponding to plasma cut-off densities 0.8 × 10¹⁹ ≤ n _e ≤ 4.4 × 10¹⁹ m^-3) are launched via quasi-optical beam combiners/polarizers and an adjustable parabolic focusing mirror selecting the beam incidence angle. GENRAY ray tracing shows that the incident O-mode and backscattered CPS X-mode beam trajectories for C-2W plasma parameters nearly overlap, allowing simultaneous detection of ñ and B̃ _r or B̃ _θ from essentially the same scattering volume.

First Direct Observation of Runaway-Electron-Driven Whistler Waves in Tokamaks

DIII-D experiments at low density (n_{e}∼10^{19}  m^{-3}) have directly measured whistler waves in the 100-200 MHz range excited by multi-MeV runaway electrons. Whistler activity is correlated with runaway intensity (hard x-ray emission level), occurs in novel discrete frequency bands, and exhibits nonlinear limit-cycle-like behavior. The measured frequencies scale with the magnetic field strength and electron density as expected from the whistler dispersion relation. The modes are stabilized with increasing magnetic field, which is consistent with wave-particle resonance mechanisms. The mode amplitudes show intermittent time variations correlated with changes in the electron cyclotron emission that follow predator-prey cycles. These can be interpreted as wave-induced pitch angle scattering of moderate energy runaways. The tokamak runaway-whistler mechanisms have parallels to whistler phenomena in ionospheric plasmas. The observations also open new directions for the modeling and active control of runaway electrons in tokamaks.

Are there increased periprocedural complications with the MRI-conditional Medtronic Revo SureScan Pacing System? : A meta-analysis

BACKGROUND

The use of magnetic resonance imaging (MRI)-conditional permanent pacemakers has increased significantly. In this meta-analysis, we examine the safety of MRI-conditional pacing systems in comparison with conventional systems.

METHODS

An electronic search was performed using major databases, including studies that compared the outcomes of interest between patients receiving MRI-conditional pacemakers (MRI group) versus conventional pacemakers (control group).

RESULTS

Six studies (5 retrospective and 1 prospective non-randomised) involving 2,118 adult patients were identified. The MRI-conditional pacemakers, deployed in 969 patients, were all from a single manufacturer (Medtronic Pacing System with 5086 leads). The rate of pacemaker lead dislodgement (atrial and ventricular) was significantly higher in the MRI group (3% vs. 1%, OR 2.47 (95% CI 1.26; 4.83), p = 0.008). The MRI group had a significantly higher rate of pericardial complications (2% vs. 1%, OR 4.23 (95% CI 1.18; 15.10), p = 0.03) and a numerically higher overall complication rate in comparison with the conventional group (6% vs. 3%, OR 2.02 (95% CI 0.88; 4.66), p = 0.10) but this was not statistically significant.

CONCLUSIONS

In this meta-analysis, the rates of pacemaker lead dislodgement and pericardial complications were significantly higher with the Medtronic MRI-conditional pacing system.

Evaluation of low-frequency operational limit of proposed ITER low-field-side reflectometer waveguide run including miter bends

The present design concept for the ITER low-field-side reflectometer transmission line (TL) consists of an ∼40 m long, 6.35 cm diameter helically corrugated waveguide (WG) together with ten 90° miter bends. This paper presents an evaluation of the TL performance at low frequencies (33-50 GHz) where the predicted HE₁₁ mode ohmic and mode conversion losses start to increase significantly. Quasi-optical techniques were used to form a near Gaussian beam to efficiently couple radiation in this frequency range into the WG. It was observed that the output beams from the guide remained linearly polarized with cross-polarization power levels of ∼1.5%-3%. The polarization rotation due to the helical corrugations was in the range ∼1°-3°. The radiated beam power profiles typically show excellent Gaussian propagation characteristics at distances >20 cm from the final exit aperture. The round trip propagation loss was found to be ∼2.5 dB at 50 GHz and ∼6.5 dB at 35 GHz, showing an inverse increase with frequency. This was consistent with updated calculations of miter bend and ohmic losses. At low frequencies (33-50 GHz), the mode purity remained very good at the exit of the waveguide, and the losses are perfectly acceptable for operation in ITER. The primary challenge may come from the future addition of a Gaussian telescope and other filter components within the corrugated guide, which will likely introduce additional perturbations to the beam profile and an increase in mode-conversion loss.

Curcumin: An age-old anti-inflammatory and anti-neoplastic agent

Curcumin is a natural anti-inflammatory agent that has been used for treating medical conditions for many years. Several experimental and pharmacologic trials have demonstrated its efficacy in the role as an anti-inflammatory agent. Curcumin has been shown to be effective in treating chronic conditions like rheumatoid arthritis, inflammatory bowel disease, Alzheimer's and common malignancies like colon, stomach, lung, breast, and skin cancers. As treatments in medicine become more and more complex, the answer may be something simpler. This is a review article written with the objective to systematically analyze the wealth of information regarding the medical use of curcumin, the "curry spice", and to understand the existent gaps which have prevented its widespread application in the medical community.