Sensors for Biomass Monitoring in Vegetated Green Infrastructure: A Review

Bioretention cells, or rain gardens, can effectively reduce many contaminants in polluted stormwater through phytoremediation and bioremediation. The vegetated soil structure develops bacterial communities both within the soil and around the vegetation roots that play a significant role in the bioremediative process. Prediction of a bioretention cell's performance and efficacy is essential to the design process, operation, and maintenance throughout the design life of the cell. One of the key hurdles to these important issues and, therefore, to appropriate designs, is the lack of effective and inexpensive devices for monitoring and quantitatively assessing this bioremediative process in the field. This research reviews the available technologies for biomass monitoring and assesses their potential for quantifying bioremediative processes in rain gardens. The methods are discussed based on accuracy and calibration requirements, potential for use in situ, in real-time, and for characterizing biofilm formation in media that undergoes large fluctuations in nutrient supply. The methods discussed are microscopical, piezoelectric, fiber-optic, thermometric, and electrochemical. Microscopical methods are precluded from field use but would be essential to the calibration and verification of any field-based sensor. Piezoelectric, fiber-optic, thermometric, and some of the electrochemical-based methods reviewed come with limitations by way of support mechanisms or insufficient detection limits. The impedance-based electrochemical method shows the most promise for applications in rain gardens, and it is supported by microscopical methods for calibration and validation.

Impact of Landfill Gas Exposure on Vegetation in Engineered Landfill Biocover Systems Implemented to Minimize Fugitive Methane Emissions from Landfills

Engineered landfill biocovers (LBCs) minimize the escape of methane into the atmosphere through biological oxidation. Vegetation plays a crucial role in LBCs and can suffer from hypoxia caused by the displacement of root-zone oxygen due to landfill gas and competition for oxygen with methanotrophic bacteria. To investigate the impact of methane gas on vegetation growth, we conducted an outdoor experiment using eight vegetated flow-through columns filled with a 45 cm mixture of 70% topsoil and 30% compost, planted with three types of vegetation: native grass blend, Japanese millet, and alfalfa. The experiment included three control columns and five columns exposed to methane, as loading rates gradually increased from 75 to 845 gCH₄/m²/d over a period of 65 days. At the highest flux, we observed a reduction of 51%, 31%, and 19% in plant height, and 35%, 25%, and 17% in root length in native grass, Japanese millet, and alfalfa, respectively. The column gas profiles indicated that oxygen concentrations were below the levels required for healthy plant growth, which explains the stunted growth observed in the plants used in this experiment. Overall, the experimental results demonstrate that methane gas has a significant impact on the growth of vegetation used in LBCs.

POS1406 EVALUATING THE QUALITY OF CARE FOR HEART FAILURE HOSPITALIZATIONS IN INFLAMMATORY ARTHRITIS- A POPULATION-BASED COHORT STUDY

Background

Individuals with inflammatory arthritis (IA) have an increased risk of heart failure (HF). Little is known if the quality of HF care differs among patients with IA compared to other chronic diseases such as diabetes mellitus (DM).

Objectives

We examined adherence to quality-of-care indicators for HF hospitalizations among patients with IA compared to those with DM but no IA and the general population (without IA or DM).

Methods

We linked multiple population-based health datasets to construct a cohort of adults living in Ontario, Canada on January 1, 2011 and followed to December 2020. The IA cohort was identified using validated case definitions and included patients with rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis. Comparison cohorts included adults with DM but no IA and general comparators without DM or IA. We included all subjects with a first HF hospitalization and who were alive at the time of discharge. We summarized the percentage of subjects in each of the 3 exposure groups who achieved recommended quality process measures [1]: (1) % receiving echocardiogram, (2) % receiving electrocardiogram, (3) % receiving a chest x-ray; and (4) % seen by a physician within 7 days of discharge. For those over the age of 65 years in whom medication information was universally available, we examined how many were dispensed evidence-based therapies: (5) % prescribed β-blocker, (6) % prescribed angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, (7) % prescribed mineralocorticoid receptor antagonist. We categorized adherence as perfect, moderate, or poor based on the number of measures achieved and compared proportions using pair-wise chi-squared tests.

Results

A first HF hospitalization occurred in 5,836 IA patients, 33,553 DM patients and 62,256 general comparators. The crude incidence rate for HF in IA was 2.70 per 1000/PY and was significantly higher compared to the general population (0.84 per 1000/PY), but lower compared to the DM cohort (5.01 per 1000/PY, p< 0.001). Mean age at time of HF hospitalization was significantly higher in the IA group (78 years) with more females affected (58%) compared to either the DM or general population group (p<0.001). All groups had high achievement of testing process measures and there were no differences in perfect adherence between the IA vs. DM and IA vs. general population comparators (Table 1). For those >65 years of age, patients with IA were less likely to achieve perfect adherence for medication quality indicators compared to either the DM or general population.

Table 1.

Percentage in each of three exposure groups achieving the recommended HF quality measures.

Process MeasureIA GroupDM GroupGeneral Population1.Echocardiogram90.6%91.1%89.5%2.Electrocardiogram97.4%97.4%97.3%3.Chest x-ray99.7%99.6%99.6%4.Health care provider visit within 7 days of discharge39.0%38.9%38.7%Perfect Adherence (achieving 1, 2,3 and 4 above)33.0%33.0% (p=0.43, IA vs. DM)32.2% (p=0.15, IA vs general population)5.Beta-blocker prescribed64.8%70.5%66.6%6.Angiotensin-converting enzyme inhibitor or angiotensin receptor blocker prescribed54.8%61.3%56.2%7.Mineralocorticoid receptor antagonist prescribed20.3%19.9%21.2%Perfect Adherence (achieving 5, 6 and 7 above)10.6%12.0% (p=<0.001, IA vs. DM)12.0% (p=0.02, IA vs general population)

Conclusion

HF quality indicators are adhered to in a high proportion of patients with IA following HF hospitalization. However, reasons for lower HF medication prescribing in IA compared to other high-risk conditions, such as DM, requires further evaluation. It will also be important to determine if adherence to HF quality of care translates to reduced long-term outcomes such as repeat HF hospitalizations and cardiovascular mortality, which we are currently exploring.

References

[1]Ontario HQ. Recommendations for Adoption: Heart Failure Care in the Community 2019 [Available from: http://www.hqontario.ca/Evidence-to-Improve-Care/Quality-Standards

Disclosure of Interests

Bindee Kuriya Speakers bureau: Abbvie, Gilead, Pfizer, Lihi Eder Speakers bureau: Abbvie, UCB, Pfizer, Eli Lily, Novartis and Sandoz, Jessica Widdifield: None declared, Laura Ferreira-Legere: None declared, Irene JH Jeong: None declared, Jiming Fang: None declared, Anna Chu: None declared, Jacob Udell: None declared

POS0905 ACHIEVEMENT OF PARTIAL REMISSION AND INACTIVE DISEASE IN UPADACITINIB-TREATED PATIENTS WITH ANKYLOSING SPONDYLITIS

Background:

Assessment of SpondyloArthritis international Society (ASAS) response criteria and AS Disease Activity Score (ASDAS) are both commonly used, rigorous composite indices consisting of components with relevance to patients. Clinically meaningful thresholds for these measures have been defined to reflect partial remission (PR), inactive disease (ID), and low disease activity (LDA).

Objectives:

To study the association of ASAS PR and ordinal ASDAS disease categories (including ASDAS ID, which is the most stringent category of this composite score) in upadacitinib (UPA)-treated patients with AS.

Methods:

In the SELECT-AXIS 1 (NCT03178487) study, biologic DMARD naïve-patients (pts; ≥18 y) with active AS and intolerance/contraindication or inadequate response to ≥2 NSAIDs were randomized 1:1 to UPA 15 mg once daily (QD) or placebo (PBO).1 At wk 14, pts entered an open-label extension (OLE) of UPA 15 mg QD; pts randomized to PBO were switched to UPA. This post hoc analysis assessed the responsiveness of individual ASAS and ASDAS core components among pts who achieved ASAS PR. The association of ASAS PR with achievement of ASDAS ID (ASDAS <1.3), ASDAS LDA (ASDAS <2.1 but ≥1.3) or ASDAS high disease activity (HDA)/very HDA (VHDA) (ASDAS ≥2.1 for HDA/VHDA) was also assessed by measures including Youden index, distance to perfect point, and sensitivity/specificity equality. These evaluations were performed in pts randomized to UPA from baseline (BL; continuous UPA, assessed at wk 14) and those who were randomized to PBO and switched to UPA upon entry in the OLE (PBO to UPA; re-baselined at wk 14 and assessed at wk 32, representing 18 wks of UPA exposure).

Results:

At wk 14, for the continuous UPA group, 16 pts (19%) achieved ASAS PR. At wk 32, following 18 wks of UPA exposure for the PBO-to-UPA group, 28 pts (33%) achieved ASAS PR. Among both groups (continuous UPA and PBO-to-UPA), improvements were seen across all core components (Figure 1). Of the 44 total pts who achieved ASAS PR, 91% achieved either ASDAS ID or LDA. The majority of patients who achieved ASAS PR achieved ASDAS ID in the continuous UPA and PBO-to-UPA groups: 11/16 (69%) and 16/28 (57%), respectively. For the continuous UPA group, the remaining 5 pts who achieved ASAS PR also achieved ASDAS LDA (Table 1). ASAS PR was associated with ASDAS categories in the following manner: the highest rate of ASAS PR was achieved for ASDAS ID followed by ASDAS LDA followed by ASDAS HDA/VHDA. The cutoff of 1.3 (the upper threshold for ASDAS ID) was a better discrimination threshold for ASAS PR than the cutoff of 2.1 (the upper threshold for ASDAS LDA).

Conclusion:

Nineteen percent of pts receiving UPA from BL achieved ASAS PR after 14 wks of treatment, with similar results seen in pts who were originally randomized to PBO and switched to UPA at wk 14. A consistent improvement was seen across all core components of ASAS among those who achieved ASAS PR with UPA treatment. The achievement of ASAS PR was most closely associated with the achievement of ASDAS ID, providing further clarity on the reduction of disease activity in AS pts treated with UPA.

References:

[1]van der Heijde, et al. Lancet. 2019;394(10214):2108-2117.

Table 1.

Association Between ASAS PR and ASDAS Clinical Thresholds (ID/LDA/HDA or VHDA)

ASDAS ID(<1.3)ASDAS LDA(1.3 to <2.1)ASDAS HDA or VHDA(≥2.1)Continuous UPA Groupn=15n=31n=39 ASAS PR Responders (n=16)1150 ASAS PR Non-responders (n=69)42639PBO to UPA Groupn=25n=35n=25 ASAS PR Responders (n=28)1684 ASAS PR Non-responders (n=57)92721

P<0.001 for association of ASAS PR with the ordered ASDAS categories of ID-LDA-HDA, for both Continuous UPA Group and PBO to UPA Group. P-value calculated from Cochran-Armitage trend test for association of ordinal categories.

ASAS, Assessment of SpondyloArthritis international Society response criteria; ASDAS, AS Disease Activity Score; HDA, high disease activity; ID, inactive disease; LDA, low disease activity; PBO, placebo; PR, partial remission; UPA, upadacitinib; VHDA, very high disease activity.

Acknowledgements:

AbbVie funded this study and participated in the study design, research, analysis, data collection, interpretation of data, reviewing, and approval of the publication. All authors had access to relevant data and participated in the drafting, review, and approval of this publication. No honoraria or payments were made for authorship. Medical writing support was provided by J Urbanik of AbbVie and M Hovenden and J Matsuura of Complete Publication Solutions, LLC (funded by AbbVie).

Disclosure of Interests:

Atul Deodhar Speakers bureau: Novartis and Pfizer, Consultant of: Novartis, Pfizer, AbbVie, Eli Lilly, UCB Pharma, GlaxoSmithKline, Galapagos, Janssen, Boehringer Ingelheim and Celgene, Amgen., Grant/research support from: AbbVie, Eli Lilly, UCB Pharma, GlaxoSmithKline, Andrew Ostor Consultant of: AbbVie, BMS, Roche, Janssen, Lilly, Novartis, Pfizer, UCB, Gilead, and Paradigm, anna maniccia Shareholder of: AbbVie, Employee of: AbbVie, Fabiana Ganz Shareholder of: AbbVie, Employee of: AbbVie, Tianming Gao Shareholder of: AbbVie, Employee of: AbbVie, Alvina Chu Shareholder of: AbbVie, Employee of: AbbVie, Denis Poddubnyy Speakers bureau: AbbVie, BMS, Lilly, MSD, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Biocad, Gilead, GSK, Lilly, MSD, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, Lilly, MSD, Novartis, and Pfizer

OP0144 EFFICACY AND SAFETY OF UPADACITINIB IN PATIENTS WITH ACTIVE ANKYLOSING SPONDYLITIS: 1-YEAR RESULTS FROM A RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED STUDY WITH OPEN-LABEL EXTENSION

Background:

Upadacitinib (UPA) was efficacious and well tolerated vs placebo (PBO) during the first 14 weeks (wks) of the phase 2/3 SELECT-AXIS 1 study in patients (pts) with active ankylosing spondylitis (AS) who had an inadequate response to NSAIDs.1

Objectives:

To report efficacy and safety of UPA through 1 year in the SELECT-AXIS 1 study.

Methods:

In SELECT-AXIS 1 (NCT03178487) pts were randomized 1:1 to UPA 15 mg once daily (QD) or PBO; at wk 14, pts continued in the 90-wk open-label extension and received UPA 15 mg QD; reported here are data up to wk 64. The study enrolled pts (≥18 y) with active AS (defined as BASDAI ≥4 and pt assessment of back pain ≥4 [numeric rating scale, 0–10] at screening and baseline [BL]) who had inadequate response to ≥2 NSAIDs or intolerance to or contraindication for NSAIDs and were biologic DMARD naive. Efficacy assessments included percentage of pts with Assessment of SpondyloArthritis international Society (ASAS) 20/40 response, ASAS partial remission, BASDAI50, AS Disease Activity Score (ASDAS) and change from BL in ASDAS and BASFI. Data are reported as observed and by using non-responder imputation (NRI). Treatment-emergent adverse events (TEAEs) were reported as events per 100 patient-years (PY) up to January 31, 2020.

Results:

Of 187 pts, 178 pts (each n=89 for UPA and PBO arms) completed wk 14 on study drug and entered the open-label extension; 160 pts completed wk 64. Efficacy was maintained or continued to improve throughout the study in the continuous UPA group: 85% (95% CI, 77%–93%) of pts achieved ASAS40 at wk 64 in the as-observed analysis and 72% (63%–81%) in the NRI analysis (Figure). Pts who switched from PBO to UPA at wk 14 showed similar speed of onset and magnitude of response vs pts initially randomized to UPA: 81% (95% CI, 72%–89%) in the as-observed analysis and 70% (61%–80%) in the NRI analysis achieved ASAS40 at wk 64 (Figure). Similar results were observed for other efficacy endpoints (Figure). Among all 182 pts receiving UPA, 618 AEs were reported. AEs leading to discontinuation and serious AEs were low (Table). No serious infections, active tuberculosis, venous thromboembolic events, gastrointestinal perforation, major adverse cardiovascular events, renal dysfunction, or deaths were reported.

Table 1.

TEAEs per 100 PYs

Events/(E/100 PY)UPA 15 mg QDN=182 (237.6 PY)Any AE618 (260.1)Serious AE14 (5.9)AE leading to discontinuation15 (6.3)Infections205 (86.3) Opportunistic infection*2 (0.8) Herpes zoster†5 (2.1)Creatine phosphokinase elevation‡28 (11.8)Hepatic disorder§24 (10.1)Neutropenia||7 (2.9)Anemia||3 (1.3)Lymphopenia||2 (0.8)Malignancy¶1 (0.4)Death0

AE, adverse event; PY, patient-year; QD, once daily; TEAE, treatment-emergent AE; UPA, upadacitinib.

*Two non-serious events of esophageal candidiasis in the same patient.

†Five events in 4 patients; all non-serious and limited to 1 dermatome.

‡All events were non-serious and none led to study drug discontinuation; majority were asymptomatic.

§Majority based on asymptomatic alanine aminotransferase/aspartate aminotransferase elevations; all were non-serious and none led to study drug discontinuation.

||All events were non-serious and none led to study drug discontinuation.

¶Squamous cell carcinoma of tongue in 61-year-old male former smoker; no reasonable possibility to be study drug related per investigator.

Conclusion:

UPA 15 mg QD showed sustained and consistent efficacy over 1 year. Pts who switched from placebo to UPA at wk 14 showed a similar efficacy response compared with pts who received continuous UPA. No new safety findings were observed compared with safety data from the UPA clinical development program in other indications.2

References:

[1]van der Heijde D, et al. Lancet. 2019;394(10214):2108-2117.

[2]Cohen, et al. Arthritis Rheumatol. 2019;71(suppl 10).

Acknowledgements:

AbbVie funded this study and participated in the study design, research, analysis, data collection, interpretation of data, reviewing, and approval of the publication. All authors had access to relevant data and participated in the drafting, review, and approval of this publication. No honoraria or payments were made for authorship. Medical writing support was provided by M Hovenden and J Matsuura of ICON plc (North Wales, PA) and was funded by AbbVie.

Disclosure of Interests:

Atul Deodhar Speakers bureau: Novartis, Pfizer, Consultant of: AbbVie, Boehringer Ingelheim, Celgene, Eli Lilly, Galapagos, GlaxoSmithKline, Janssen, Novartis, Pfizer, UCB, Grant/research support from: AbbVie, Eli Lilly, GlaxoSmithKline, Novartis, Pfizer, UCB, Désirée van der Heijde Consultant of: AbbVie, BMS, Cyxone, Eisai, Galapagos, Gilead, GlaxoSmithKline, Lilly, Novartis, Pfizer, and UCB Pharma, Joachim Sieper Speakers bureau: AbbVie, Janssen, Lilly, Merck, and Novartis, Consultant of: AbbVie, Janssen, Lilly, Merck, and Novartis, Filip van den Bosch Speakers bureau: AbbVie, Celgene, Eli Lilly, Galapagos, Gilead, Janssen, Novartis, Pfizer, and UCB Pharma, Consultant of: AbbVie, Celgene, Eli Lilly, Galapagos, Gilead, Janssen, Novartis, Pfizer, and UCB Pharma, Walter P Maksymowych Consultant of: AbbVie, Boehringer Ingelheim, Celgene, Galapagos, Gilead, Janssen, Lilly, Novartis, Pfizer, UCB Pharma, Grant/research support from: AbbVie, Novartis and Pfizer, Tae-Hwan Kim Speakers bureau: AbbVie, Celltrion, Kirin, Lilly, and Novartis, Mitsumasa Kishimoto Consultant of: AbbVie, Amgen-Astellas BioPharma, Asahi-Kasei Pharma, Astellas, Ayumi Pharma, BMS, Chugai, Daiichi-Sankyo, Eisai, Eli Lilly, Gilead, Janssen, Kyowa Kirin, Novartis, Pfizer, Tanabe-Mitsubishi, Teijin Pharma, and UCB Pharma, Andrew Ostor Consultant of: AbbVie, BMS, Roche, Janssen, Lilly, Novartis, Pfizer, UCB, Gilead, and Paradigm, Bernard Combe Speakers bureau: AbbVie, Lilly, Merck, Consultant of: AbbVie, Lilly, Gilead, Janssen, Novartis, Roche-Chugai, and Sanofi, Grant/research support from: AbbVie and Lilly, Yunxia Sui Shareholder of: AbbVie, Employee of: AbbVie, xin wang Shareholder of: AbbVie, Employee of: AbbVie, Alvina Chu Shareholder of: AbbVie, Employee of: AbbVie, In-Ho Song Shareholder of: AbbVie, Employee of: AbbVie

Designing a continuous data-driven feedback and learning initiative to improve electronic prescribing: an interdisciplinary quality improvement study

Introduction

The WHO Global Patient Safety Challenge aims to reduce severe avoidable medication-related harm by 50% by 2023[1]. Research suggests that providing timely, trusted feedback that incorporates relevant action can improve practice. However, a key barrier is lack of prescribing error data. Hospital electronic prescribing (EP) data may help address this gap.

Aims

To explore approaches for continuously monitoring medication safety signals using existing or new EP data, and to deliver personalised prescribing feedback and learning to improve patient safety.

Methods

We conducted a feasibility study (November 2019 - February 2020) on a 28-bed adult gastroenterology. This ward was chosen because of a high prescribing error rate. All foundation year 1 and 2 doctors, and pharmacists on the ward, participated in the study. The study team comprised pharmacists, doctors, quality improvement experts and clinical analysts, and used a quality improvement approach to design and test (i) methods for extracting electronic data to calculate prescribing accuracy rates, (ii) ways to refine a paper-prototype of an electronic pharmacists’ interventions form, (iii) potential digital medication safety indicators, and (iv) approaches for feedback for doctors to augment existing verbal feedback from pharmacists. Data were documented in accordance with local information governance and analysed using Excel. Acceptability and usability was assessed through verbal feedback from participants during weekly huddles. Outcome measures: feasibility of using EP to determine prescribing accuracy, user acceptability and usability of data collection, feedback and learning by pharmacists and doctors. We also measured changes in prescribing accuracy rate, pharmacists’ interventions, and quality of prescribing for targeted problematic medications.

Results

Extracting EP data required multiple data linkages to be configured and validated, and not all required data were available. Potential digital medication safety indicators: utility of the reason code ‘prescribed in error’ and actions by pharmacists to modify medications were limited by underuse and lack of data granularity. After testing different ways to extract relevant EP data, we eventually used a combination of EP and manual retrospective review of electronic patient records to determine prescribing accuracy rates. An intervention form was redesigned to tally interventions and capture details for contextual learning for email feedback to doctors and weekly prescribing improvement huddles. Doctors reported emails as timely and helpful for gaining new prescribing- and system-related knowledge. Pharmacists reported intervention data as providing invaluable evidence to drive improvement.

Statistical process control charts showed no special cause variation around a mean prescription accuracy rate of 98% for inpatient orders, and 87% for discharge orders. By contrast, pharmacists recorded a mean of 10 interventions/day with 7 special cause variation (above upper control limit of 19) in the first two months. Omission of venous thromboembolism prophylaxis was identified as a priority medication issue. Specific prescriber- and system-based improvements were suggested (Jan 2020), some implemented (Feb 2020) and others fed back to the thrombosis committee (Feb 2020).

Conclusion

Harnessing the potential of EP data to improve medication safety requires the workforce to have a deeper understanding of the EP data structure and processes. Using a quality improvement approach, we developed a feedback and learning model that is acceptable and useful to pharmacists and doctors. Further research should explore adapting the approach to other clinical areas.

Reference

1. Sheikh, A., Dhingra-Kumar, N., Kelley, E., Kieny, M. and Donaldson, L. The Third Global Patient Safety Challenge: Tackling Medication-Related Harm. Bulletin of the World Health Organization. World Health Organisation. 2017;95:546-546A.

Characterization of domestic wastewater released from 'green' households and field study of the performance of onsite septic tanks retrofitted into aerobic bioreactors in cold climate

This study aimed to investigate the efficacy of private septic systems retrofitted into aerobic bioreactors with 'SludgeHammer' technology. In addition, the study attempted to characterize the strength of domestic wastewater released from 'green' households practicing water conservation strategies. Ten retrofitted onsite septic systems were studied in the Edmonton area, Alberta (AB) Canada during winter. These systems could remove BOD₅ and TSS by 92 ± 5 and 92 ± 6% respectively which, according to Albertan regulatory standards, were characteristic removal efficiencies of the secondary treatment in the subsequent drain field. These removal efficiencies were remarkable given the strength of the influent wastewater. The raw wastewater carried significantly high pollutant concentrations (1160 ± 350 mg BOD₅/L, 1653 ± 1174 mg TSS/L, 99 ± 19 mg NH₄⁺-N/L, 100 ± 56 mg TN/L, and 39 ± 28 mg PO₄^3--P/L), characterizing it as high-strength domestic wastewater. Mixing provided by the aerator could only suspend 1/34^th (3% m/m) of the solids in the bioreactor and consequently released significantly low solid concentrations (195 ± 206 mg TSS/L) into the final treatment component. As such, this technology did not impair the natural function of septic tanks or did not create any unintended excessive solid loading on drain field as a consequence of the added mixing energies provided by the active aeration. Nitrogen balance suggested the possibility of simultaneous nitrification and denitrification (SND) in the aerobic bioreactors. In some cases, PO₄^3--P removal efficiency was as high as that in enhanced biological phosphate removal (EBPR) process (81-97%). Phosphorus balance estimated that non-assimilative pathways (i.e., EBPR + biologically induced phosphate precipitation (BIPP)) contributed 50-99% to overall phosphorus removal in the system. Long HRTs, high influent BOD₅ and anaerobic/aerobic zoning in the bioreactor most likely provided favorable conditions for SND and high phosphorus removal efficiencies in the retrofitted onsite wastewater treatment systems (OWTS).

Nutrient leaching behavior of green roofs: Laboratory and field investigations

Despite the benefits of green roofs in managing stormwater quality, green roofs especially at their early age might leach nutrients. Research in this regard is still very limited. Therefore, this paper conducted both the laboratory and field observations to characterize and model the leaching of nutrients including nitrogen (N) and phosphorus (P) and to examine the discrepancy in knowledge produced from these two settings. The experiment revealed that the higher the initial nutrient contents of media were, the higher the degree of nutrient leaching was. The nutrient leaching from both the laboratory cells and the field green roof declined temporally, which was largely explained by the cumulative inflow. The semi-physically based nutrient leaching model generally captured the nutrient leaching from both the laboratory cells (R² in the range of 0.87-0.98) and the field green roof (R² in the range of 0.28-0.86). The mass balance analysis for the laboratory cells demonstrated that the masses of nutrients leached in outflow were 85-112% of the nutrients reduced in media in general (except P of two laboratory cells). The analysis and modeling results supported that media was the primary source for nutrients leached and the pattern of nutrient leaching was consistent with wash-off being the dominant process. The results also revealed the difference in the P leaching between the laboratory cells and the field green roof. Apart from the wash-off, other chemical and biological processes and/or nutrient sources might play non-negligible roles on the P leaching of the field green roof, implied by the relatively low performance of the models (R² of approximately 0.30 in both the regression analysis and the nutrient leaching model). The difference observed between the laboratory experiment and the field observation also calls into attention when translating knowledge derived from laboratory experiments into real practice.

Hospital readmissions after catheter ablation for atrial fibrillation among patients with heart failure in the United States

Background

Catheter ablation for atrial fibrillation may improve quality of life and long-term mortality among patients with heart failure.

Purpose

The rates of hospital readmission after catheter ablation for atrial fibrillation among patients with an established diagnosis of heart failure are largely unknown. We aimed to assess the rates and causes of 30-day readmission among patients with heart failure undergoing catheter ablation vs. medical therapy for atrial fibrillation in the United States.

Methods

The 2016 Nationwide Readmissions Database was screened for patients with diagnosis of heart failure and atrial fibrillation using the 10th Revision of International Classification of Diseases codes. Patients undergoing catheter ablation for atrial fibrillation were grouped separately from those treated medically for atrial fibrillation. Thirty-day readmissions were assessed for both groups.

Results

The analytical cohort included 749,776 (national estimate of 1,421,673) patients with heart failure and atrial fibrillation. This included 2,204 patients that underwent catheter ablation. Patients treated with catheter ablation had lower 30-day readmissions compared to the medical therapy group (16.8% vs 20.1%, p&lt;0.001). Fifty-five percent of all readmissions among the catheter ablation cohort were related to cardiac events. Heart failure exacerbation (40%) and arrhythmia (36%) were the most common cardiac causes for readmission after catheter ablation (Figure).

Conclusions

In a contemporary nationwide analysis of patients with heart failure and atrial fibrillation, compared to medical therapy those treated with catheter ablation for atrial fibrillation had fewer 30-day readmissions after index hospital discharge. The most common cause for readmission among patients treated with catheter ablation was heart failure exacerbation and arrhythmia.

Causes of readmission

Funding Acknowledgement

Type of funding source: None

Implications of pacemaker implantation after TAVR: insights from the Nationwide Readmissions Database

Introduction

Conduction disturbances after transcatheter aortic valve replacement (TAVR) requiring permanent pacemaker (PPM) implantation are a well-known procedural complication. Data on the effect of post-TAVR PPM implantation on 30-day readmissions is scarce.

Methods

The Nationwide Readmissions Database (NRD) is a nationally representative sample of all US hospitalizations, representing over 35 million discharges. The 2016 NRD was used to identify patients who underwent TAVR and PPM implantation from January to November 2016. Propensity matching was used to balance baseline clinical characteristics.

Results

Of the 44,607 patients who underwent TAVR, 4,878 (10.9%) required permanent pacemaker implantation during their index hospitalization. Patients requiring PPM during their index admission for TAVR had a higher crude median length of stay (LOS) (5d vs. 3d, p&lt;0.001), median cost of index admission ($61,604 vs. $45,513, p&lt;0.001) and rate of 30-day readmission (14.5% vs 11.2%, p&lt;0.001). After 2:1 propensity matching, PPM patients still had a higher median LOS (5d vs. 3d, p&lt;0.001), median cost of index admission ($61,902 vs. $41,162, p&lt;0.001), and rate of 30-day readmission (13.8% vs 11.1%, p=0.003). Patients who received PPM were more likely to be older (81.1 vs 80.3, OR 1.01, CI 1.01–1.02), diabetic (OR 1.27, 1.13–1.44), obese (OR 1.22, 1.05–1.43), and have right (OR 4.35, 3.72–5.09) or left (OR 1.80, 1.51–2.15) bundle branch blocks on multivariate analysis. Causes of readmission in patients with and without PPM were predominantly non-cardiac (62.9% vs 68.0%). Heart failure was the most common cause of readmission for both groups (18.4% vs 14.6%). Median cost of readmissions ($8716 vs $8250, p=0.34) and LOS (4d vs 4d, p=1) were not significantly different during readmissions.

Conclusions

Based on a nationally representative sample, 10.9% of patients undergoing TAVR required PPM implantation during the index hospitalization. Age, diabetes, obesity, and right or left bundle branch blocks were significant predictors of PPM implantation. PPM implantation resulted in significantly higher LOS, costs, and 30-day readmissions on propensity-matched analysis.

Funding Acknowledgement

Type of funding source: None

Efficient Ground-State Cooling of Large Trapped-Ion Chains with an Electromagnetically-Induced-Transparency Tripod Scheme

We report the electromagnetically-induced-transparency (EIT) cooling of a large trapped ^{171}Yb^{+} ion chain to the quantum ground state. Unlike conventional EIT cooling, we engage a four-level tripod structure and achieve fast sub-Doppler cooling over all motional modes. We observe simultaneous ground-state cooling across the complete transverse mode spectrum of up to 40 ions, occupying a bandwidth of over 3 MHz. The cooling time is observed to be less than 300  μs, independent of the number of ions. Such efficient cooling across the entire spectrum is essential for high-fidelity quantum operations using trapped ion crystals for quantum simulators or quantum computers.

The impact of media, plants and their interactions on bioretention performance: A review

Bioretention systems have gained considerable popularity as a more natural approach to stormwater management in urban environments. The choice of bioretention media is frequently cited as one of the critical design parameters with the ultimate impact on the performance of the system. The goal of this review is to highlight data that challenge the importance of media as being the dominant design parameter and argue that the long-term performance is shaped by the interactions between media and the living components of a bioretention system, especially vegetation. Some of the key interactions are related to the impact of plant roots on media pore structure, which has implications on infiltration, storage capacity, and treatment. Another relevant interaction pertains to evapotranspiration and the associated impacts on the water balance and the water quality performance of bioretention systems. The impacts of vegetation on the media are highlighted and actual, as well as potential, impacts of plant-media interactions on bioretention performance are presented.

Augmentation of Biogranules for Enhanced Performance of Full-Scale Lagoon-Based Municipal Wastewater Treatment Plants

This study investigated the treatment performance of lagoon-based municipal wastewater treatment plants (LWWTPs) inoculated by proprietary biogranules. Augmentation process included enhancing the microbial community of lagoon basins by weekly addition of biogranules over the treatment seasons (summer and fall). Effluent qualities before and after the augmentation process were compared, and the results were reported as "enhanced treatment efficiencies, E_E". Very low concentrations of 5-day biochemical oxygen demand (BOD₅), total nitrogen (TN), total Kjeldahl nitrogen (TKN), ammonium nitrogen (N-NH₄), and total phosphorus (TP) were detected at discharge points after the augmentation process, which corresponded to enhanced treatment efficiencies of 86, 74, 72, 92.7, and 71%, respectively. Significant reduction in total coliform and E. coli concentrations in the effluents (91 and 98%, respectively) demonstrated the capability of granule-based lagoons in destroying pathogens. Adding biogranules to lagoons was an efficient remedy for excess sludge buildup in short and long runs. Hence, inoculating lagoon plants using biogranules was suggested as an effective technique to augment rural wastewater treatment facilities.

Pilot-scale investigation on nutrient removal characteristics of mineral-rich aerobic granular sludge: Identification of uncommon mechanisms

This study investigated nutrient removal characteristics and the related pathways in aerobic granular reactors using three pilot-scale granular sequencing batch reactors (GSBRs) treating wastewaters of diverse carbon and nutrient strength. The GSBRs were operated with alternating (AN/O/AX/O_SBR and AN/O_SBR) and purely-aerobic (O_SBR) operation modes. Mineral-rich aerobic granules with hydroxyapatite (HAp) core were cultivated in all the three GSBRs. The highest nitrogen removal efficiency (75%) was achieved in AN/O/AX/O_SBR and O_SBR and the lowest (22%) in AN/O_SBR, establishing a quasi-linear relationship with organic loading rate (OLR). Phosphorus removal efficiencies of 55-63% were achieved in the GSBRs despite different influent PO₄-P concentrations. Heterotrophic nitrification and biologically-induced phosphate precipitation (BIPP) became the dominant nutrient depletion pathways, contributing 61-84% and 39-96% to overall ammonium nitrogen and phosphorus removal, respectively. A direct relation was noted between heterotrophic nitrification efficiency (η_{Heterotrophic nitrification}) and nutrient availability, as nitrification efficiencies of 18 and 64% were observed for COD:N_inf of 5 and 20, respectively. Whereas, BIPP efficiency (η_BIPP) established inverse relation with (COD:P)_inf and (Ca:P)_inf and direct relation with phosphorus concentration beyond microbial growth requirement. Core heterotrophic nitrifiers and bio-calcifying species were identified as {Thauera and Flavobacterium} and {Flavobacterium, Acinetobacter, Pseudomonas, and Corynebacterium}, respectively. Ca-P crystallization was proposed to be via phosphate precipitation on calcite surfaces. Granulation mechanism was proposed as crystallization on bio-aggregates' periphery and then crystal growth toward the core.

P6572Sinus arrest post-cardioversion

Introduction

Sinus arrest remains a recognized but likely underreported complication of cardioversion, with incidence ranging widely in the literature, from virtually 0% to 1.5%. After a case of elective cardioversion resulting in the need for ECMO support, we investigated possible risk factors that could help predict adverse outcomes after cardioversion.

Hypothesis

Cardioversion, while generally benign, is not without risks, and further study may help elucidate predictors of morbidity and mortality.

Methods

We retrospectively reviewed data of all patients who underwent cardioversion at three hospitals within the Lifespan health system, Rhode Island Hospital, Newport Hospital, and the Miriam Hospital, between 2000 and 2015. 23 patients who experienced sinus arrest after cardioversion, and characteristics of these patients were compared with those of 3:1 age-and-gender matched controls using binomial logistic regression analysis on Stata.

Results

Of 12,156 patients who underwent cardioversion, 23 patients (57% male, mean age 78±14), or 0.18%, experienced immediate post-cardioversion sinus arrest, defined as absence of sinus activity for greater than five seconds. Compared with 3:1 age-and-gender-matched controls who underwent cardioversion without incident, binomial logistic regression revealed that paroxysmal atrial fibrillation (OR 11.8; 95% CI 1.85–75.72; p=0.009), beta-blocker use (OR 58.0; 95% CI 2.4–1404.48; p=0.013), Amiodarone use (OR 19.9; 95% CI 2.0–198.32; p=0.011), and elevated ventricular rate (CV 0.028; 95% CI 0.0031–0.053; p=0.027) were statistically significant predictors of sinus arrest after cardioversion. Calcium-channel blocker use, Digoxin use, age, gender, PR interval, QRS duration, and corrected QT interval were not significant associations.

Conclusions

Sparse data exists regarding characteristics predisposing patients to adverse outcomes following cardioversion, and further risk stratification is warranted, given the potential for significant morbidity and mortality. Our findings raise questions that demand elucidation, such as whether beta-blockers or Amiodarone should be held prior to cardioversion.

Response of green roof performance to multiple hydrologic and design variables: a laboratory investigation

Multiple factors affect green roof performance and their effects might vary at different stages of operation. This paper aimed to link green roof performance to hydrologic variables (antecedent moisture condition (AMC) and rainfall intensity) and design variables (growing medium (GM) type and depth) under multiple dimensions at the early stage of operation using laboratory experiment data. The results showed that the AMC is the most influential factor of hydrologic performance, whereas the GM type appeared to primarily affect the nutrient levels of the outflow. The significant main effects of other variables and interaction effects between two variables point to challenges in green roof design.

Characterization of proximal femoral anatomy in the skeletally-immature patient

PURPOSE

The morphology of the proximal femur has been extensively studied in the adult population. However, no literature providing a comprehensive evaluation of the anatomy in paediatric patients exists. The current study aims to characterize such anatomy in skeletally-immature patients, examine potential differences between genders, and analyze how these anatomical parameters change with age.

METHODS

Cadaveric femurs from the Hamann-Todd Osteological Collection were examined. Specimens with open physes and no skeletal disease or deformity were included for analysis. Age and gender were recorded for each specimen. Each femur was photographed in standardized modified axial and anteroposterior views. In all, 14 proximal femoral anatomical parameters were measured from these photographs. Comparisons between genders and age were calculated.

RESULTS

A total of 43 femurs from ages four to 17 years met inclusion criteria. The majority were female (56%); no difference existed in age between genders (p = 0.62). The specimens had a neutral mean neck-shaft angle (130.7º) and anteversion (12.8º), and the sphericity of the ossified femoral heads was symmetrical. Male specimens had significantly higher alpha angles (p = 0.01), posterior offset (p = 0.02), neck width (p = 0.04) and head-neck length ratio (p = 0.02) values than female specimens. Strong positive correlations exist between length/size parameters and age, while negligible correlations were noted for angular measurements.

CONCLUSIONS

This study establishes reference values for a comprehensive list of anatomical parameters for the skeletally-immature ossified proximal femur. It highlights gender differences in morphology and demonstrates that angular characteristics remain relatively stable while length parameters generally increase with age.

LEVEL OF EVIDENCE

Level III Diagnostic.

A Simple Automated Method for Detecting Recurrence in High-Grade Glioma

Our aim was to develop an automated multiparametric MR imaging analysis of routinely acquired imaging sequences to identify areas of focally recurrent high-grade glioma. Data from 141 patients treated with radiation therapy with a diagnosis of high-grade glioma were reviewed. Strict inclusion/exclusion criteria identified a homogeneous cohort of 12 patients with a nodular recurrence of high-grade glioma that was amenable to focal re-irradiation (cohort 1). T1WI, FLAIR, and DWI data were used to create subtraction maps across time points. Linear regression was performed to identify the pattern of change in these 3 imaging sequences that best correlated with recurrence. The ability of these parameters to guide treatment decisions in individual patients was assessed in a separate cohort of 4 patients who were treated with radiosurgery for recurrent high-grade glioma (cohort 2). A leave-one-out analysis of cohort 1 revealed that automated subtraction maps consistently predicted the radiologist-identified area of recurrence (median area under the receiver operating characteristic curve = 0.91). The regression model was tested in preradiosurgery MRI in cohort 2 and identified 8 recurrent lesions. Six lesions were treated with radiosurgery and were controlled on follow-up imaging, but the remaining 2 lesions were not treated and progressed, consistent with the predictions of the model. Multiparametric subtraction maps can predict areas of nodular progression in patients with previously treated high-grade gliomas. This automated method based on routine imaging sequences is a valuable tool to be prospectively validated in subsequent studies of treatment planning and posttreatment surveillance.