Cellular stress is triggered by tick-borne encephalitis virus and limits the virus replication in PMJ2-R mouse macrophage cell line

Viral infection may represent a stress condition to the host cell. Cells react to it by triggering the defence programme to restore homeostasis and these events may in turn impact the viral replication. The knowledge about tick-borne encephalitis virus (TBEV) infection-associated stress is limited. Here we investigated the interplay between TBEV infection and stress pathways in PMJ2-R mouse macrophage cell line, as macrophages are the target cells in early phases of TBEV infection. First, to determine how stress influences TBEV replication, the effect of stress inducers H2O2 and tunicamycin (TM) was tested. Viral multiplication was decreased in the presence of both stress inducers suggesting that the stress and cellular stress responses restrict the virus replication. Second, we investigated the induction of oxidative stress and endoplasmic reticulum (ER) stress upon TBEV infection. The level of oxidative stress was interrogated by measuring the reactive oxygen species (ROS). ROS were intermittently increased in infected cells at 12 hpi and at 72 hpi. As mitochondrial dysfunction may result in increased ROS level, we evaluated the mitochondrial homeostasis by measuring the mitochondrial membrane potential (MMP) and found that TBEV infection induced the hyperpolarization of MMP. Moreover, a transient increase of gene expression of stress-induced antioxidative enzymes, like p62, Gclm and Hmox1, was detected. Next, we evaluated the ER stress upon TBEV infection by analysing unfolded protein responses (UPR). We found that infection induced gene expression of two general sensors BiP and CHOP and activated the IRE1 pathway of UPR. Finally, since the natural transmission route of TBEV from its tick vector to the host is mediated via tick saliva, the impact of tick saliva from Ixodes ricinus on stress pathways in TBEV-infected cells was tested. We observed only marginal potentiation of UPR pathway. In conclusion, we found that TBEV infection of PMJ2-R cells elicits the changes in redox balance and triggers cellular stress defences, including antioxidant responses and the IRE1 pathway of UPR. Importantly, our results revealed the negative effect of stress-evoked events on TBEV replication and only marginal impact of tick saliva on stress cellular pathways.

Harnessing a real-time location system for contact tracing in a busy emergency department

BACKGROUND

With the persistent threat of emerging infectious diseases (EIDs), digital contact tracing (CT) tools can augment conventional CT for the prevention of healthcare-associated infectious disease transmission. However, their performance has yet to be evaluated comprehensively in the fast-paced emergency department (ED) setting.

OBJECTIVE

This study compared the CT performance of a radiofrequency identification (RFID)-based real-time location system (RTLS) with conventional electronic medical record (EMR) review against continuous direct observation of close contacts ('gold standard') in a busy ED during the coronavirus disease 2019 pandemic period.

METHODS

This cross-sectional study was conducted at the ED of a large tertiary care hospital in Singapore from December 2020 to April 2021. CT performance [sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and kappa] of the RTLS, EMR review and a combination of the two approaches (hybrid CT) was compared with direct observation. Finally, the mean absolute error (MAE) in the duration of each contact episode found via the RTLS and direct observation was calculated.

RESULTS

In comparison with EMR review, both the RTLS and the hybrid CT approach had higher sensitivity (0.955 vs 0.455 for EMR review) and a higher NPV (0.997 vs 0.968 for EMR review). The RTLS had the highest PPV (0.777 vs 0.714 for EMR review vs 0.712 for hybrid CT). The RTLS had the strongest agreement with direct observation (kappa=0.848). The MAE between contact durations of 80 direct observations and their respective RTLS contact times was 1.81 min.

CONCLUSION

The RTLS was validated to be a high-performing CT tool, with significantly higher sensitivity than conventional CT via EMR review. The RTLS can be used with confidence in time-strapped EDs for time-sensitive CT for the prevention of healthcare-associated transmission of EIDs.

A221 EFFECT OF PROXIMITY TO A SPECIALTY TERTIARY CENTRE ON OUTCOMES IN INFLAMMATORY BOWEL DISEASE: A POPULATION-BASED RETROSPECTIVE COHORT STUDY

Background

The etiology of inflammatory bowel disease (IBD) is unknown; however, developed nations such as Canada ranking amongst the highest worldwide. With many diseases patients in urban and rural areas have different access to care and resources.

Purpose

To describe the differences in outpatient healthcare utilization, use of biologic agents and complication of IBD based on proximity to a tertiary health care centre.

Method

A retrospective cohort study was conducted comparing IBD patients seen in IBD clinics at affiliated with Western University in London, Canada between August 2019 – December 2019. IBD patients were compared on their use of outpatient healthcare utilization, biologic agents and IBD complications based on their proximity to a tertiary care centre (>100 km and <100 km). Patients residing >100 km from a tertiary centre were termed “rural” while <100 km from a tertiary centre were termed “urban.” Retrospective chart review occurred over a six-month period between January to June 2021.

Result(s)

A total of 481 were reviewed. Of those, 97 (UC, n=29; CD, n=68) and 95 (UC, n=30; CD, n=65) met inclusion for the urban and rural groups respectively. Patient demographics were similar between the two groups except IBD disease location with pancolitis seen more commonly in urban patients compared to ileocolonic in rural patients (urban, n=39; rural, n=34). IBD patients in both groups had similar number of appointments (urban, n=20.1 ± 13.8; rural, n=17.5 ± 12.1) and endoscopic procedures (urban, n= 4.9 ± 3.1; rural, n= 4.7 ± 3.2) with their gastroenterologists. More urban patients were managed with no therapy for their IBD (urban, n=16; rural, n=5). A higher rate of rural patients were managed with biologics (urban, n=56; rural, n=66) and combination therapy (urban, n=16; rural, n=27). The most common related IBD-related complications were IBD flares (urban, n=55; rural, n=60), intestinal strictures (urban, n=25; rural, n=34), intestinal obstructions (urban, n=10; rural, n=23) and rectal/genitourinary fistulas (urban, n=6; rural, n=21). Similar numbers of intra-abdominal surgery were seen between both groups with partial bowel resection (urban, n=13; rural, n=12) and right hemicolectomy (urban, n=10; rural, n=18) as the predominant surgery in urban and rural patients, respectively.

Conclusion(s)

This study demonstrated outpatient healthcare utilization when attending specialty gastroenterology appointments and outpatient endoscopies were numerically similar in rural and urban patients. IBD patient residing further from a tertiary care centre were numerically more likely to be managed with biologics and combination therapy. However the dataset is small and generalizations cannot be made.

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None

Disclosure of Interest

None Declared

A86 CANNABIS USE IN PATIENTS WITH INFLAMMATORY BOWEL DISEASE IS HIGHER FOLLOWING LEGALIZATION OF CANNABIS IN CANADA AND IS ASSOCIATED WITH LOWER QUALITY OF LIFE

Background

Patients with inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), often experience fluctuating and unpredictable symptoms. Most individuals require chronic therapy with immunomodulators or novel biologics to maintain disease remission. In addition to conventional medical therapy, many patients also seek out alternative therapies such as cannabis. Reports in the USA suggest that cannabis is used by ~12% of UC and ~16% of CD patients, despite it being legally prohibited.

Purpose

The aim of our study is to evaluate the use of cannabis in a cohort of patients with IBD following its legalization in Canada, and to assess its effects on IBD disease severity.

Method

We conducted a prospective cohort study of adult IBD patients seen in clinic at a tertiary care center in London, ON. Patients completed an online 40-question survey that collected data on demographics, IBD disease history, cannabis use, and included the Short Inflammatory Bowel Disease Questionnaire (SIBDQ). The survey was distributed and collected by the REDCap platform maintained by Western University. The study was approved by the Western University Ethics Committee.

Result(s)

Completed surveys were obtained from 254 individuals (148 individuals with CD, 90 with UC and 16 with indeterminate colitis). Over half of participants were between 35-64 years of age and female. Fifty-three percent of participants reported life-time cannabis use and 51% of users started using cannabis only in the preceding 3 years. Individuals with CD had higher rates of recent use, defined as use within the past 6 months, when compared with UC (41% vs 31%). Cannabis was taken multiple times per week by 57% of users. Cannabis was used to treat GI symptoms by 30% of users, as well as to help with sleep (26%) and for recreation (27%). Despite side effects such as dry mouth, anxiety and concentration issues, 79% of users felt the benefits of cannabis outweighed its harms. Interestingly, only 46% of cannabis users discussed their use with their family physician or gastroenterologist. Recent cannabis users did not differ in the use of IBD medication or self-reported rates of GI symptoms. Furthermore, recent users did not differ in the rates of surgical procedures for IBD (recent 35% vs non-recent 32%). Recent cannabis users did have a significantly lower quality of life as indicated by SIBDQ scores when compared to non-recent users (recent use 37 vs non-recent use 40).

Conclusion(s)

Cannabis use among patients with IBD after its legalization is more than double the rate previously reported in the literature. Importantly, physicians are likely to be unaware of its prevalence in their practice. Cannabis was used by patients to treat GI and non-GI symptoms, and it was associated with lower SIBDQ scores. Our results suggest that physicians should inquire about Cannabis use amongst their patients with IBD, and that further studies are required to determine its effects on disease severity.

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CIHR

Disclosure of Interest

None Declared

A222 EFFECT OF CLINICAL FACTORS ON IBD TREATMENT RESPONSE: FINDINGS FROM A NOVEL SINGLE CENTER PATIENT REGISTRY

Background

Inflammatory bowel disease (IBD), comprising both Crohn’s disease as well as ulcerative colitis, has shown heterogenous response to therapy. Over the past decades, targeted biologic therapies have become the mainstay of treatment. Even with the rapid pace of progress in this field, roughly a third of patients do not show an initial response to these treatments. The ability to accurately predict treatment response to therapy would both improve patient safety and satisfaction as well as decrease costs from ineffective therapies.

Purpose

The primary aim of this project is to identify clinical factors predictive of disease response to induction biologic therapy in inflammatory bowel disease through the creation of a novel single center patient registry.

Method

Initially, a single center tissue biopsy registry of IBD patients receiving colonoscopy was created. Retrospective clinical data was subsequently collected on patients identified to have initiated or changed biologic therapy after entry into the registry. Clinical data regarding age, sex, comorbidities, lifestyle factors, time since initial diagnosis, extra intestinal manifestations, serum markers, prior IBD treatments, planned treatment, clinical response, as well as endoscopic response were collected. A Pilot study of the first 30 patients identified was undertaken. Individual clinical factors were compared between patients with a documented clinical response to biologic therapy and non-responders at the group level as well as by biologic therapy initiated.

Result(s)

No statistically significant differences in collected clinical data parameters were observed between treatment responders and non responders in aggregate as well as when sub selected by individual biologic therapy initiated, bio-naive status, and steroid dependence.

Conclusion(s)

This project has demonstrated that clinical factors alone do not adequately predict disease response in inflammatory bowel disease. Future work will expand this data registry to further clinical factors and continue patient enrolment. Next steps also include the addition of tissue level data, in particular tissue level RNA data. It is hoped that these parameters, either individually or in combination, will provide a robust and accessible predictor of response to biologic therapy in inflammatory bowel disease.

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Other

Please indicate your source of funding below:

Western University Department of Medicine

Disclosure of Interest

None Declared

A104 INVISIBLE COLONIC MALIGNANCY AND POSSIBLE IDIOSYNCRATIC DRUG-INDUCED LIVER INJURY FROM VEDOLIZUMAB IN A PATIENT WITH ULCERATIVE COLITIS, PRIMARY SCLEROSING CHOLANGITIS AND AUTOIMMUNE HEPATITIS OVERLAP SYNDROME

Background

Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract. Due to an increased risk of developing colorectal cancer, regular surveillance for dysplastic lesions via colonoscopy is recommended. Invisible dysplasia is the abnormal development of cells noted on pathology with no visible lesion seen during colonoscopy. Primary sclerosing cholangitis (PSC) is an immune-mediated liver disease leading to progressive stricturing and fibrosis of the bile ducts. There is significant association between PSC and IBD, as up to 80% of patients with PSC having underlying IBD. Drug induced liver injury (DILI) is a common cause of acute liver failure in most Western countries. Most cases of DILI are self-limited, with resolution of laboratory and clinical findings after cessation of the offending agent.

Purpose

To describe a case of invisible colonic malignancy and possible idiosyncratic drug-induced liver injury from vedolizumab (VDZ) in a patient with ulcerative colitis (UC), PSC and autoimmune hepatitis (AIH) overlap syndrome.

Method

Patient consent was obtained. Information from electronic records was extracted, including admission notes and procedural reports. A literature review was performed using Pubmed.

Result(s)

A 32-year-old Caucasian female with UC on VDZ with PSC and AIH had multiple colonoscopies performed demonstrating multifocal low-grade dysplasia. However, she remained resistant to surgery. She presented to clinic with tea-coloured urine, fatigue, and scleral icterus. Investigations revealed conjugated hyperbilirubinemia with elevation in hepatocellular liver enzymes. Imaging was consistent with large duct PSC, and liver biopsy showed grade 2 chronic hepatitis raising the possibility of large bile duct obstruction. She underwent liver transplant assessment and VDZ was held. Her bilirubin and liver enzymes recovered. Given multiple colonoscopies showing multifocal dysplastic changes and the patient declining other biologics, she would ultimately undergo total proctocolectomy with end ileostomy. Pathology demonstrated mucinous adenocarcinoma with a signet ring component.

Conclusion(s)

Both mucinous adenocarcinoma and signet ring carcinoma are more aggressive malignancies associated with poor prognosis. Found more often in younger patients, they are often diagnosed in later stages with lymphovascular invasion. Here, there was no evidence of metastases in any of the 40 lymph nodes examined, which indicated more favourable prognosis.

The mechanism by which VDZ potentially causes liver injury is unknown. Multiple therapies for PSC-AIH overlap and IBD were entertained as causative agents. However, significant improvement in clinical symptoms and serologic parameters following cessation of VDZ was temporally suggestive.

This case simultaneously highlights the importance of both timely colectomy in IBD patients with high-risk features during surveillance and early recognition and cessation of potential causative medications which induce liver injury.

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None

Disclosure of Interest

None Declared

DIFFERENCES IN OUTCOMES AMONG PATIENTS WITH ATRIAL FIBRILLATION UNDERGOING CATHETER ABLATION WITH VERSUS WITHOUT INTRACARDIAC ECHOCARDIOGRAPHY

Background

Intracardiac echocardiography (ICE) use can lead to early detection of periprocedural complications and may improve patient outcomes by providing real‐time visualization of catheter location and the treatment area during cardiac ablation (CA) for atrial fibrillation (AF).

Objective

Examine complications and 12‐month healthcare use among patients with AF undergoing CA with versus without ICE use during the procedure in a real‐world setting.

Methods

The 2015–2020 IBM MarketScan® Database was used to identify non‐elderly adults (age 18–64 years) undergoing CA for AF. Patients were classified into ICE/non‐ICE groups based on the presence or absence of ICE procedure codes. Patients in each group were matched on study covariates using propensity scores. Peri‐procedural complications, 12‐month cardiovascular (CV) or AF‐related inpatient admission, repeat CA, and cardioversion were compared using a Cox proportional hazard model.

Results

1371 patients were identified in each study cohort (ICE and non‐ICE) after propensity matching. Patients who had CA with ICE had a significantly lower rate of complications than those without (2.9% vs. 5.8%; p < .001). The risk of complications was 50% lower with ICE use (hazard ratio [HR] 0.50; 95% confidence interval [CI] 0.34–0.72). For assessment of 12‐month healthcare utilization, 1250 patients were identified in each cohort after propensity matching. ICE use was associated with a 36% lower risk of 12‐month repeat ablation (HR 0.64; 95% CI 0.49–0.83). No differences in CV‐ or AF‐related inpatient admission and cardioversion were observed.

Conclusion

Among patients with AF, the use of ICE during an ablation procedure was associated with lower incidence of complications and repeat ablation.

Mitigating emotional responses to stressors: coping strategies, modifiers and support

OBJECTIVE

The stressful nature of the intensive care unit (ICU) environment is increasingly well characterised. The aim of this paper was to explore modifiers, coping strategies and support pathways identified by experienced Intensivists, in response to these stressors.

METHOD

Prospective qualitative study employing interviews with Intensivists in two countries. Participants were asked how they mitigated their emotional responses to the stressors of the ICU. Audio-recordings were transcribed and analysed by all researchers who agreed upon emerging themes and subthemes.

RESULTS

A wide range of strategies were reported. Although several participants had sought professional help and all supported its utility, few disclosed accessing such help to others indicating stigma. Many felt a sense of responsibility for the well-being of other staff but identified barriers that suggest alternate support pathways are required. Further implications of these findings to training considerations are described.

CONCLUSIONS

Several approaches were described as regularly employed by Intensivists to mitigate ICU environmental stressors. Intensivists perceive themselves to have limited training to provide support to others; they also perceive stigma in seeking professional help.

A103 META-ANALYSIS: NEOPLASIA OF THE POUCH IN PATIENTS WITH ULCERATIVE COLITIS POST ILEAL POUCH-ANAL ANASTOMOSIS

Background

Ileal anal pouch anastomosis (IPAA) is often used for patients with severe ulcerative colitis that is refractory to medical treatment or for patients with neoplasia/dysplasia to maintain intestinal continuity. Patients with ulcerative colitis have an increased risk of developing dysplasia or colorectal cancer compared to the general population, however the need for pouch surveillance is debated. A meta-analysis was performed to identify the risk and prevalence of pouch related malignancy in patient with ulcerative colitis following IPAA.

Aims

Our aim is to assess of the rate of dysplasia and malignancy post IPAA in patients with ulcerative colitis and also assess what the factors associated with developing malignancy post IPAA

Methods

A search of Embase and Ovid MEDLINE was conducted to identify studies from 2014 to June 2021 that reported the incidence of dysplasia or malignancy following IPAA in patients with ulcerative colitis. Abstracts and conferences were not included in the search. The studies were assessed for relevance and data were extracted independently by two reviewers.

Results

This analysis included 11, 268 patients with variable follow-up. The evidence was graded as low-certainty due to significant heterogeneity and low-quality studies. The pooled prevalence of carcinoma or dysplasia (low or high grade) in pouch or the rectal cuff was 0.4% [95% CI 0.2- 0.7]. However, in patients with prior colectomy for colorectal cancer the odds ratio was 32.20 [95% CI 15.58 - 66.53] for pouch malignancy. Significant heterogeneity and variability of the pooled studies was identified (I2 = 77.5%).

Conclusions

Although the rate of dysplasia or malignancy was 0.4% for all IPAA, the odds ratio for these outcomes in patients with IPAA for prior malignancy was 32.20 [95% CI 15.58 - 66.53]. Further studies are required to validate these findings.

Funding Agencies

None

A142 IMPACT OF HLADQA1*05G>A GENETIC-SCREENING FOR OPTIMAL ANTI-TNF THERAPY IN INFLAMMATORY BOWEL DISEASE: A PRELIMINARY REPORT

Background

Genetic variation in the human leukocyte antigen ( HLA) gene is strongly associated with the formation of anti-drug antibodies to tumor necrosis factor-alpha antagonists (anti-TNF) in inflammatory bowel disease (IBD). It is also associated anti-TNF loss of response and treatment discontinuation.

Aims

We aimed to evaluate the utility of preemptive HLADQA1*05G&gt;A screening to reduce the incidence of treatment-related adverse events in an IBD population by lessening the need for combination therapy in those who do not carry the risk allele. We also assessed for the occurrence of anti-TNF anti-drug antibody (ADA) formation, anti-TNF loss of response, treatment discontinuation compared to an unscreened population.

Methods

A non-randomized open label study is ongoing in IBD patients being considered for anti-TNF therapy. Participants received either pre-treatment HLADQA1*05G&gt;A screening (prospective-screening group, n=25/110 recruited), with the addition of one of azathioprine or methotrexate to anti-TNF therapy (combination therapy) if identified as a high risk variant carrier (G/A or A/A) or received combination therapy without undergoing prospective HLADQA1*05A&gt;G screening (control group, n=25/110 recruited). All participants will be followed for up to 1 year and observed for the occurrence of any adverse drug events, formation of anti-TNF drug antibodies (ADA), anti-TNF loss of response and anti-TNF discontinuation.

Results

To date, the prevalence of HLADQA1*05 G/A and A/A was 20% in the prospective-screening group and thus 20% (n=5/25) received combination therapy and 80% (n=20) received anti-TNF monotherapy. All participants in the control group (n=25/25) received combination therapy. Considering all groups, 78% (n=39/50) received infliximab, while 22% (n=11/50) received adalimumab. To date, the median follow-up period is 5 (IQR=4) months. Fewer adverse drug events have been reported in the prospective-screening group versus the control group (16.7% vs 33.3%, odds ratio 0.40, 95%CI=0.12–1.56, p=0.18). Anti-TNF ADA formation and treatment discontinuation were similar between groups (prospective-screening, 0% versus control, 4.2%). A higher proportion of controls experienced anti-TNF loss of response (16.7% vs 8.3%, p=0.38).

Conclusions

Preemptive HLADQA1*05G&gt;A screening appears to reduce the need for combination therapy when using anti-TNF agents in an IBD population. Fewer drug-related adverse events are reported to date in the screened cohort without a concomitant increase in deleterious outcomes such as ADA formation or anti-TNF discontinuation. Completion of this study will help define whether or not HLADQA1*05G&gt;A-screening is a clinically-actionable and relevant tool for guiding the application of combination therapy in IBD.

Funding Agencies

Lawson Health Research Institute

A225 VACCINE-PREVENTABLE DISEASES IN HOSPITALIZED PATIENTS WITH END-STAGE LIVER DISEASE/CIRRHOSIS: A NATIONWIDE COHORT ANALYSIS

Background

Cirrhosis is associated with immune dysfunction, which increases susceptibility to infection and subsequent hospitalization. Vaccination of this high-risk patient population can mitigate the risk of infection.

Aims

Data from the National Inpatient Sample (NIS) was analyzed to compare the prevalence of vaccine-preventable diseases (VPD) among hospitalized patients both with and without cirrhosis.

Methods

The 2013 NIS database was interrogated using ICD-9-CM codes to identify patients with cirrhosis and VPD. Baseline characteristics were compared (see: Table 1). Univariate and multivariate regression models identified risks associated with VPD adjusting for survey procedures.

Results

313,710 patients were hospitalized for VPD, including 13,080 patients (4.1%) with cirrhosis (see: Table 1) Patients with cirrhosis were more likely to be hospitalized with pneumococcal pneumonia (odds ratio [OR] = 1.45 [95% CI 1.29 – 1.63], P <0.001), hepatitis A (OR = 7.04 [95% CI 5.96 – 8.31], P <0.001) and hepatitis B (OR = 14.41 [95% CI 12.53 – 14.36], P <0.001) infections compared to patients without liver cirrhosis. Patients with cirrhosis were less likely to have an infection with influenza (OR = 0.55 [95% CI 0.49 – 0.62], P <0.001), human papillomavirus (HPV) (OR = 0.57 [95% CI 0.43 – 0.75, P < 0.001) and varicella zoster (OR = 0.78 [95% CI 0.69 – 0.89], P <0.001). Minimal differences in hospitalizations for haemophilus influenzae or meningococcal infections were noted between groups.

Odds ratios for VPD adjusting for age, sex, race, patient location, patient income, hospital type and bed-size, mortality risk, type 2 diabetes mellitus, malignancy, human immunodeficiency virus (HIV), organ transplantation and immunodeficiency:

pneumococcal pneumonia (OR = 1.27 [95% CI 1.13 – 1.44], P < 0.001), hepatitis A (OR = 5.99 [95% CI 5.02 – 7.15], P < 0.001); and hepatitis B (OR = 11.07 [95% CI 10.24 – 11.97], P < 0.001).

Conclusions

These results emphasize the importance of vaccinating patients with cirrhosis against pneumococcal pneumonia, hepatitis A and hepatitis B infections to reduce hospitalization

Table 1: Baseline characteristics of patients with cirrhosis and without cirrhosis presenting with a vaccine preventable disease.

Funding Agencies

None

A166 CANNABIS USE IN CANADIAN INDIVIDUALS WITH INFLAMMATORY BOWEL DISEASE FOLLOWING LEGALIZATION OF CANNABIS

Background

Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are characterized by remitting and relapsing symptoms of abdominal pain, diarrhea, nausea, fatigue, and poor sleep. Most patients with IBD require chronic immunosuppressive therapy to maintain their disease in remission. Due to their disease chronicity, individuals often seek additional complementary or alternative medicines such as cannabis to treat their symptoms. Reports from the US show cannabis use in 12% of UC and 16% of CD patients. However, these numbers are likely underestimates given that cannabis remains illegal in many states.

Aims

The aim of our study is to evaluate the use of cannabis in a cohort of patients with IBD and to assess its association with IBD disease severity.

Methods

We conducted a prospective cohort survey of adult patients with IBD seen in tertiary care in London Health Sciences Centre. A 40-question online survey was completed by consenting patients and collected data on demographics, IBD disease history, cannabis use, and included the Short Inflammatory Bowel Disease Questionnaire (SIBDQ) as a measure of disease severity. The study was approved by the Western University Ethics Committee. Statistical analyses was performed using a Chi squared test for categorical data, and a two-tailed t-test for continuous data.

Results

Completed surveys were obtained from 210 individuals (135 individuals with CD and 75 with UC) and demographics were similar between the CD and UC cohort. Fifty-six percent of participants reported cannabis use at least once in their lifetime, with 38% of participants reporting cannabis use in the preceding 6 months. Interestingly, 46 percent of life-time cannabis users did not divulge their cannabis use to their physicians. In patients with UC, those who actively used cannabis were less likely to be on 5-ASA therapy (9 active users vs 22 non-users, p&lt;0.05). Medical therapy was otherwise similar between cannabis users and non-users. Surgical rates were similar between cannabis users and non-users amongst both IBD subtypes. With respect to the burden of disease, patients with CD reported higher rates of abdominal pain if they were active users, however, overall SIBDQ scores were not altered by cannabis use (21 user vs 20 non-user). Similarly, SIBDQ scores were similar amongst patients with UC who were cannabis users and non-users (20 user vs 16 non-user).

Conclusions

Cannabis use in patients with IBD is very common and much higher than previously reported prior to the legalization in Canada, but its use is not associated with lower disease severity based on patient reported outcomes. Our study also reveals that patients often do not report this use to their doctors so physicians must be aware of its prevalence amongst their IBD patient population.

Funding Agencies

None

Randomized comparison of proximal and distal radial access for coronary angiography and interventions

Funding Acknowledgements

Type of funding sources: None.

Introduction

Vascular access for coronary procedures is of paramount important not only for successful procedure but also to prevent complications. In comparison to femoral access, proximal radial artery (PRA) access at wrist is associated with decreased bleeding complications and mortality.  The most important complication of PRA access is radial artery occlusion Use of the proximal radial artery (PRA) approach at wrist has several limitations:  the need to supinate the hand, which can exacerbate chronic joint pain, the depth of the radial artery in large arms, which could make arterial puncture challenging even under ultrasound guidance, the risk of sporadic bleeding in the forearm, and the risk of radial artery occlusion. All above limitations can be overcome by distal radial artery (DRA) access in anatomical snuff box.  Randomized Studies are lacking for the comparison between DRA and PRA approach in coronary procedures.

Aims and objective

To compare safety, efficacy and feasibility between PRA and DRA approach in randomized fashion.

Material and methods

This was single center randomized controlled trial. 320 patients were randomized in PRA and DRA groups. PRA approach was in wrist and DRA approach was in anatomical snuff box. Primary endpoint was cannulation failure (failure to achieve radial access) and transradial failure (failure to complete procedure after successful access). Secondary safety outcome includes major (compartment syndrome, need for vascular surgery, hand dysfunction, nerve palsy ,arteriovenous fistula, hematoma requiring blood transfusion, proximal radial artery occlusion) and minor (radial artery spasm, hematoma not requiring transfusion or causing compartment syndrome, ecchymosis, local edema, paresthesia, pseudoaneurysm) complications; secondary efficacy outcome were puncture attempts, cannulation time, procedure time, radiation dose, hemostasis time  and quality of life endpoint  was pain score .

Results

 Each group was having 160 patients. In DRA group 73.9 % were CAG and 26.1 % were PCI; in PRA group and 75.7 were CAG and 24.3 were PCI. Cannulation failure was more in DRA group (7.5 % vs 2.5 %, P &lt; 0.001) without difference in transradial failure (n = 3 vs 4, p =0.764). There were no major complications in both groups except PRAO which was significantly less in DRA group (0 % vs 5.2 %, p= 0.007). Puncture attempts, cannulation time, pain score were more in DRA (1.65 vs 1.29, P &lt; 0.001;3.23 vs 2.62 minutes, p &lt; 0.001;25.5 vs 21.6 minutes, p = 0.039 respectively). There was no significant difference for minor complications in both groups.

Conclusion

DRA approach is as safe and feasible as PRA approach and causes significantly less PRAO. DRA approach may be advocated as default approach where radial access is chosen for coronary procedures. Abstract Figure. primary outcome  Abstract Figure. Procedural characteristic

Clinical significance of epicardial fat in suspected angina pectoris: an observational study

Funding Acknowledgements

Type of funding sources: None.

Background

Epicardial adipose tissue (EAT) is the visceral fat between pericardium and visceral epicardium and is the source of several endocrine and inflammatory mediators. It also has paracrine affects in the neighboring coronary arteries.

Objective

 To evaluate the association of EAT with subclinical atherosclerosis (carotid intima media thickness & flow mediated vasodilation), ultrasonic and anthropometric measures of abdominal fat, metabolic syndrome and coronary artery disease (CAD) concurrently.

Material and methods

Patients who underwent computed tomography (CT) coronary angiography for suspected CAD were prospectively included. All underwent anthropometric measurements, laboratory investigations, ultrasonic measurement of liver fat grade & B-mode hepatorenal ratio, carotid intima media thickness (CIMT), flow mediated vasodilation (FMD), CT measurement of epicardial fat thickness (EFT) & epicardial fat volume (EFV) along with CT coronary angiography. Study population was divided into 2 groups on the basis of presence or absence of CAD and were compared. The relationship between risk factors and presence of CAD was assessed by logistic regression analysis. To define EFT and EFV value predictive of the presence of significant CAD, the area under (AUC) the receiver operating characteristic (ROC) curve was calculated. Correlation between EFT as well as EFV with anthropometric and laboratory parameters, CIMT and FMD were assessed by Pearson correlation coefficient.

Results

Total 54 patients were included in study. Mean age was 54 years, 66% were diabetic and 33% were hypertensive. Mean CIMT, FMD, EFT and EFV were 0.70 + 0.27 cm; 5.64 + 2.64%; 5.51 + 2.50 mm and 60.6 + 28.6 cc, respectively. Total 34 (62.96%) patients were detected to have CAD. EFT as well as EFV were significantly higher in CAD group (3.31 + 2.34 vs 6.24 + 1.91mm; p= &lt;0.001, 72.5 + 22.3 vs 40.4 + 27.1cc; p= &lt;0.001); in patients with metabolic syndrome (83.3 + 18.4 vs 49.2 + 26.1cc; p &lt; 0.001, 7.13 + 1.49 vs 4.16 + 2.32mm; p &lt; 0.001). Both, EFV & EFT were significantly correlated with the abdominal fat, CIMT and FMD. Smoking, age and EFV were the independent predictors for CAD.  EFV &gt;31.65cc predicted the presence of CAD (sensitivity 91.25%, specificity 60%, AUC = 0.798, 95% CI = 0.665-0.930) and EFT &gt;2.85mm predicted the presence of CAD (sensitivity 94.1%, specificity 65%, AUC= 0.820, 95% CI= 0.687-0.953).

Conclusions

Epicardial fat is significantly associated with presence of CAD, metabolic syndrome, visceral fat, CIMT and FMD. CT measured epicardial fat may be included with CT based CAD lesion assessment and CT coronary calcium score to screen the patients of suspected angina pectoris. Abstract Figure. Epicardial adipose tissue  Abstract Figure. EFV and CAD

Behavioural responses of Intensivists to stressors in Intensive Care

BACKGROUND

The hospital intensive care unit (ICU) environment encompasses sick patients who present for care in health crisis. Healthcare in this setting is complex, often involving the co-ordination of multiple professional teams, all under significant time pressures. The sequelae for staff interacting in this dynamic and often volatile setting are variable, depending upon their coping skillset and their familiarity with the stressors.

AIMS

The primary aim of this study was to describe and in doing so, normalize the behavioural responses expressed by ICU doctors (Intensivists) in response to stressful workplace events. The secondary aim was to identify those responses that contributed to resilience.

METHODS

A prospective qualitative study of senior Intensivists using a semi-scripted iterative interview. Data were transcribed and thematically analysed with verbatim quotations selected to support coding choices.

RESULTS

Nineteen experienced Intensivists from three sites in Australia and Israel participated. Clinicians described conscious, physiological and professional responses to stressors, including sense-making and taking time to process information with appropriate support. Two of the most important mitigation processes revealed were the use of reflective learning and preventative practice changes to prevent future errors. These were overlaid with the importance of disclosure and transparency in clinical work.

CONCLUSIONS

Repeated exposure to stressful events potentiates burnout, wherein staff no longer experience satisfaction and enjoyment in what they do. This paper presents the behavioural responses that experienced Intensivists described in relation to stressful events in the ICU, including steps taken to mitigate the effects of these events on their personal well-being.

Distal radial access in the right anatomical snuffbox for coronary angiography and interventions: a prospective observational study

Background

Distal radial access in the anatomical snuffbox is a novel technique for vascular access. However, limited clinical data is available, mainly limited to the left distal radial access. In view of the paucity of data on right distal radial access; this study was conducted to assess the feasibility, efficacy and safety of the right distal radial approach as a default access route for transradial catheterization.

Methods

We enrolled 159 consecutive patients with a palpable right distal radial pulse prospectively at a single center. A detailed clinical evaluation, laboratory tests and echocardiographic examination was done. Doppler examination of distal radial artery for its patency and size was done before puncture attempt. The right distal radial artery was punctured using the back wall technique. Primary outcome was successful puncture of distal right radial artery. Secondary outcomes were number of puncture attempts, pain score, radial artery spasm, forearm and distal radial hematoma, proximal and distal radial artery occlusion, bleeding and other vascular complications, access site crossover due to distal radial access failure, contrast volume used, and radiation dose.

Results

Distal radial puncture was successful in 144/159 (90.1%) patients. The mean distal radial artery diameter was 2.2±0.25 mm. Mean pain score by visual analogue scale was 2.36±1.9. There were no bleeding events. Snuffbox hematoma was seen in 11 (7.6%) patients and forearm hematoma occurred in 5 (3.5%) patients. There were 9 (6.3%) cases of radial spasm, 4 (2.8%) cases of radial occlusion at distal access site and 1 (0.7%) forearm radial artery occlusion.

Conclusions

The right distal radial access is a feasible, safe and efficacious alternative approach for coronary angiogram and interventions.

Funding Acknowledgement

Type of funding sources: None.

An innovative route for valorising iron and aluminium oxide rich industrial wastes: Recovery of multiple metals

Several industrial wastes including biomass, fly ashes, red mud, mill scales, water treatment residues, have significant concentrations of metal oxides: Fe₂O₃, Al₂O₃, TiO₂, SiO₂ etc. Several efforts have been made towards recovering metals within these wastes. Rather than recovering one metal at a time, we report a novel approach for simultaneously extracting multiple metals from mixed oxides in a single process step. Using three distinct furnaces/heating regimes, the carbothermic reduction of Fe₂O₃/Al₂O₃/SiO₂ system was investigated at 1450-1700 °C for up to 2 h over a wide composition range. Complete reduction was achieved for both Fe₂O₃ and SiO₂ in all cases leading to the formation of Fe and Fe-Si alloys. The reduction of alumina at moderate temperatures was the key challenge. No alumina reduction was observed during reductions at 1450 °C. A partial reduction of alumina and the formation of Fe-Al alloys was detected in the Al₂O₃/Fe₂O₃/C system at 1550 °C. The formation of Fe-Si-Al alloys was also observed in the Fe₂O₃/SiO₂/Al₂O₃/C system at 1550 °C. Complete reduction of alumina was observed at 1600-1700 °C, even for up to 50 wt% alumina in the system. Optimal operating conditions and reference standards were established for the simultaneous recovery of multiple metals from waste oxides. While conserving natural resources, this novel route will lower the burden on waste storage facilities with significant contributions to the economic and environmental sustainability of industrial waste management.

A103 PIVOTING IN A PANDEMIC: THE IMPACT OF COVID-19 ON THE PROVISION OF CARE FOR PATIENTS WITH INFLAMMATORY BOWEL DISEASE: A PRELIMINARY ANALYSIS

Background

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak, also known as COVID-19, was declared a worldwide pandemic in March of 2020. Since the onset of the pandemic, the focus of many healthcare systems has shifted toward limiting non-essential visits to hospitals in order to prioritize and allocate resources toward treating those affected by COVID-19, and preventing further exposures. While the effect of COVID-19 has been felt amongst many patient populations, those with inflammatory bowel disease (IBD) have been particularly impacted through delayed appointments and endoscopy, which is critical in disease monitoring.

Aims

We aimed to determine how changes to the provision of IBD care due to the COVID-19 pandemic have affected IBD patients.

Methods

A retrospective cohort study was conducted using administrative data comparing IBD patients admitted to the gastroenterology ward from March 17 to August 31 2019, with IBD patients admitted from March 17 to August 31 2020 at a tertiary care centre in London, Ontario. Patients were reviewed to assess differences in care utilization and IBD-related outcomes such as hospitalization, surgery and length of stay and in-patient drug therapy.

Results

A total of 538 patients (259 in 2019 cohort and 279 in 2020 cohort) were reviewed with 48 and 60 IBD patients meeting the inclusion criteria for 2019 and 2020 respectively. Patient demographics were similar between 2019 and 2020 cohort for age, sex, rurality, disease type, and biologic exposure. A greater proportion of patients were admitted with IBD flares in 2020 (86.7% vs 75%, p=0.03). Furthermore, the 2020 cohort also had a 45% increase in in-patient surgical consultations (p=0.07), a 50% increase in in-patient IBD-related surgeries (p=0.39), a 69% increase in inpatient Remicade prescription (p=0.13) and a 70% increase in infectious complications at presentation to hospital (p=0.21). A shorter median length of stay was reported for patients in the 2020 cohort (4 days IQR 3.95 vs 5.85 IQR 4.65, p=0.09).

Conclusions

Preliminary data suggest that during the COVID-19 pandemic, we have seen more deleterious outcomes in our IBD patients such as increased flares necessitating hospital admission. There was also a non-significant trend toward increased infectious complications as well as in-patient surgeries and need for in-patient Remicade. Though these results cannot be fully interpreted due to the need for further sampling, they suggest that IBD patients may be at-risk for poor outcomes in the current climate of medical care. Completion of this study will help define the full impact of care shifts related to reducing the spread of the novel coronavirus on IBD patients and highlight areas of care that need careful assessment and consideration to protect IBD patient health.

Funding Agencies

None

A224 LIVER CIRRHOSIS AND VENOUS THROMBOEMBOLISM: A NATIONAL INPATIENT SAMPLE STUDY

Background

The sequelae of decompensated cirrhosis include a reduction in both hepatic coagulation factors and platelets. While historically it was felt that patients with cirrhosis were naturally anticoagulated, recent studies have refuted this. As a result, cirrhotic patients may be a risk for development of venous thromboembolism (VTE). Conflicting data regarding VTE risks limits guidance for clinicians.

Aims

National Inpatient Sample (NIS) data were analyzed to compare the prevalence of VTE among hospitalized patients with and without cirrhosis.

Methods

NIS is a database of US inpatient admissions. The 2014 NIS database was interrogated using ICD-9-CM codes to identify adult patients with cirrhosis and VTE. Baseline characteristics for patients with and without cirrhosis were compared. Multivariate regression models identified risks of VTE adjusting for survey procedures. Data were presented with odds ratio (OR) with 95% confidence intervals (95% CI). A p-value &lt;0.05 was statistically significant.

Results

605,825 patients with cirrhosis were included. VTE occurred in 8,940 patients with cirrhosis and 627,490 controls (1.5% and 2.2% respectively). The corresponding values for PE were 0.5% and 1.1%; and for DVT were 1.1% and 1.4%. The OR for VTE in patients with cirrhosis was 0.547 [95% CI (0.520–0.576), p &lt;0.001] when adjusting for risk factors for VTE (table 1).

Conclusions

Prevalence of VTE was lower among inpatients with cirrhosis compared to controls. Use of anticoagulation was not controlled as these data were not available, which could limit some associations. Further prospective studies are needed to overcome the limitations of retrospective analysis.

Funding Agencies

None

Factors influencing the release of potentially toxic elements (PTEs) during thermal processing of electronic waste

The release of potentially toxic elements as airborne fine particulates is a significant environmental risk associated with recycling e-waste. Some of these may redeposit near emission sites or be transported over long distances causing wide-spread pollution. With an aim to identify key factors affecting particulate emissions, we report novel investigations on the adsorptive capture of particulate matter (PM) released during low temperature pyrolysis (600 °C; 15 min) of waste printed circuit boards (PCBs). A significant proportion of the released particulates (5.3 to 37%) were captured by adsorbents located downstream and in close proximity to the emitting source. Data was collected for four different PCBs and three adsorbents: alumina, silica-gel and activated carbon. With sizes ranging from nanoparticles to over 10 µm, adsorbed particulates were present as fines, spheres, oblongs, clusters and larger particles with no specific shape. Of the 24 elements identified initially in waste PCBs, only 14 were detected in released particulates: major PTEs- Zn, Sn, Pb and Cu (up to 400 ppm); minor PTEs- Ni, Mn, Cd, Cr and Ba (up to 10 ppm); trace PTEs- Co, In, Bi, Be and Sb (up to 1 ppm). Key factors influencing the release of PTEs during thermal processing were identified as basic elemental characteristics, densities, melting points, vapor pressures, initial concentrations, local bonding and mechanical strength. These results show that the presence of low melting point/high vapour pressure elements (Zn, Pb, Sn) should be minimised for a significant reduction in PTE emissions during e-waste processing.

A231 UNDERSTANDING THE IMPACT OF TNF-ALPHA ANTAGONISTS ON THE SEVERITY OF NON-MELANOMA SKIN CANCER IN INFLAMMATORY BOWEL DISEASE AND THE CONSEQUENCES FOR THERAPY

Background

Non-melanoma skin cancer (NMSC) accounts for at least 40% of all new cancer diagnoses in Canada annually and presents a significant cost to the health care system due to the volume of cases. The incidence of NMSC in patients with Inflammatory Bowel Disease (IBD) is higher when compared to the general population. Generally, in a non-IBD population, the risk of further NMSC progression is low, however, little data exists that highlights differences in clinical course of patients diagnosed with NMSC who have IBD and are TNF-α antagonist exposed. It is unclear if TNF-α antagonist therapy should be discontinued in this patient population.

Aims

Our goal is to determine whether TNF-α antagonist exposure in IBD is associated with a high risk NMSC presentation at diagnosis, as defined by the National Comprehensive Cancer Network (NCCN) stratification. Our secondary objectives include presence of positive margins following resection, presence of metastatic disease on initial presentation, requirement of additional therapy to treat NMSC, number of patients who had TNF-α antagonist therapy discontinued following diagnosis of NMSC and number of individuals with recurrent NMSC.

Methods

Four hundred and twenty-four IBD patients seen at London Health Sciences Centre were reviewed. We have identified 22 patients who were diagnosed with NMSC. Twelve patients had a pre-NMSC TNF-α antagonist exposure while 10 patients who developed an NMSC and had no TNF-α antagonist exposure prior to NMSC diagnosis.

Results

Preliminary results of the primary outcome demonstrate that fifty-percent (6/12) of patients who have been exposed to TNF antagonist therapy presented with a high risk NMSC lesion at diagnosis compared to 40% (4/10) who were not exposed (OR 5.16, 95%CI 0.47–57.00; p = 0.181). Preliminary results of the secondary outcomes suggest that 25% (3/12) of patients exposed to TNF-α antagonist had positive margins compared with 0% (0/10) of patients who were not exposed. No patients in either group presented with metastatic disease. Twenty-five percent (3/12) of patients in the exposed group received more advanced treatment compared with 0% (0/10) in the non-exposed group. Eight percent (1/12) of patients in the TNF-α antagonist group had their IBD therapy changed from a TNF-α antagonist to an alternative biologic class, and 17% of patients (2/12) in the TNF-α antagonist group had recurrent NMSC lesions.

Conclusions

In conclusion, preliminary results suggest that TNF-α antagonist exposure may be associated with higher risk NMSC lesion at presentation. Further expansion of the sample size is required to explore these hypotheses further.

Funding Agencies

None

A254 IGA-MEDIATED WARM AUTOIMMUNE HEMOLYTIC ANEMIA IN A PATIENT WITH CROHN’S DISEASE ON VEDOLIZUMAB

Background

Iron deficiency anemia and anemia of chronic disease are relatively common manifestations of Crohn’s disease. Autoimmune hemolytic anemia, however, is quite rare with few reported cases.

Aims

To present a rare case of IgA-mediated warm autoimmune hemolytic anemia in Crohn’s Disease.

Methods

A chart review and literature search were performed in preparation of this case report.

Results

A 21-year-old male with a recent diagnosis of Crohn’s disease on Vedolizumab presents to infusion clinic with generalized weakness, coke-colored urine and weight loss. Physical examination was remarkable for tachycardia and jaundice. Laboratory investigations revealed profound anemia with IgA-mediated DAT positivity. The patient remained admitted in hospital for a prolonged period. Bone marrow biopsy, CT imaging and infectious workup were negative. Vedolizumab was held and treatment with both high-dose corticosteroids and rituximab was required. Eventually, the anemia would stabilize and Vedolizumab was safely resumed as an outpatient.

Conclusions

Here we report a both rare and challenging case of IgA-mediated DAT positive autoimmune hemolytic anemia in a patient with Crohn’s disease who was successfully treated with corticosteroids and rituxumab.

Funding Agencies

None

Pentoxifylline Does Not Influence Maximum Ultrafiltration Rates and Peritoneal Transport in Rats

Previous publications have suggested that peritoneal capillary blood flow and filtration pressure equilibrium may limit ultrafiltration rates with very hypertonic exchanges. Rats were treated with pentoxifylline, which decreases blood viscosity by increasing red blood cell deformability. Decreases in blood viscosity should reduce microcirculatory resistance and increase effective capillary flow. Transport studies were performed after 2, 4, and 8 weeks of therapy with peritoneal dialysis solutions containing 15 grams % dextrose and using 30-min cycles. Even though rats ingested near the maximum recommended dose of pentoxifylline (20 mg/kg) significant changes in blood viscosity and shear stress were not detected compared to controls. Also, there were no significant differences in clearances of urea and phosphorus, glucose absorption, protein losses, and net ultrafiltration compared to controls.

P41 Correlation of doppler ultrasound assessment of carotid femoral pulse wave velocity with coronary artery disease

Funding Acknowledgements

self

Background

Arterial stiffness is an important cardiovascular risk factor. Carotid femoral pulse wave velocity (cfPWV) is simple noninvasive  method to determine aortic stiffness. Arterial stiffness measures, cfPWV in particular,  have been found to be correlate with stroke and peripheral artery disease. Usually SphygmoCor or Complior are used to calculate cfPWV. Doppler ultrasound can serve as an alternative to these methods. 

Purpose

To assess cfPWV using doppler ultrasound and study its correlation with coronary artery disease and its severity. 

Methods

cfPWV was assessed by ultrasound Doppler in patient aged 20-70 years undergoing coronary angiography.  cfPWV was measured by sequential recordings of arterial pressure waveform at the carotid and femoral arteries with a Doppler ultrasound with ECG gating and calculated as the distance between the carotid and the femoral sampling site divided by the time interval. 

Result

Of the 358 subjects studied, 243 had coronary artery disease(CAD) (&gt;50% diameter stenosis) and were further divided into single, double or triple vessel disease groups. 115 patients  had mild CAD (&lt; 50% stenosis) or no CAD and served as controls. Baseline characteristics were similar except diabetes (more common in CAD group)(39.09% v/s 27.82%). cfPWV was found to increase with age in all groups. cfPWV was not significantly affected  by sex, diabetes, dyslipidemia, BMI, smoking or hypothyroidism. Mean cfPWV was significantly higher in patients with CAD (8.99 v/s 6.51 m/s, p &lt; 0.001) and hypertensives (8.71 v/s 7.83 m/s, p &lt; 0.001). Patients with triple vessel disease(TVD) had significantly higher cfPWV (10.12 m/s) than those with double(DVD)(8.84 m/s) or single vessel disease(SVD)(8.28m/s)(p &lt; 0.001). Multinomial logistic regression revealed an odds ratio of 2.00, 2.375 and 3.368 respectively for SVD, DVD and TVD groups in comparison to controls (p &lt; 0.001). cfPWV value &gt; 7.25 m/s predicted CAD with sensitivity 78.6 % and specificity 74.8% (AUC =0.848, P &lt; 0.001). 

Conclusion

Carotid femoral pulse wave velocity can be measured noninvasively by ultrasound Doppler. cfPWV increases with age and hypertension and has strong correlation with coronary artery disease and its severity. The cfPWV can be an independent risk factor and may be utilized for cardiovascular risk prediction.

Abstract P41 Figure. cfPWV in various subgroups.

P1496Use of strain, strain rate, tissue velocity imaging and endothelial function for early detection of cardiovascular involvement in young diabetics

Background

Subtle structural and functional changes may precede the onset of overt global left ventricular dysfunction and obvious reduction of ejection fraction (EF), especially in young diabetics. Data pertaining to tissue velocity indices (TVI) and strain imaging to assess regional myocardial function and flow mediated vasodilatation is limited in young patients with diabetes.

Purpose

To evaluate conventional echocardiography parameters, tissue doppler indices, global and regional strain, carotid intimal medial thickness (CIMT), endothelial dependent (FMD) and independent function (NMD) of brachial artery in young patients (age <18 years) with type 1 diabetes and compare them with matched controls.

Methods

Conventional echocardiography parameters, tissue velocity indices (TVI) parameters along with strain (S), and strain rate (SR) in basal and mid left ventricular (LV) lateral wall, right ventricular (RV) lateral wall and septum were measured in 50 young diabetics (age 15.16±2.95 years, mean HBA1c 8.15±1.37 gm %) and 25 controls (age 15.60±2.51 years). Flow-mediated dilatation (FMD), nitrate mediated dilatation and carotid intimal media thickness (CIMT) were also estimated.

Results

Conventional echocardiography parameters were similar in patients and controls however deceleration time of the mitral inflow velocity (EDT) was significantly shorter in patients when compared with controls (149.06±31.66 vs. 184.56±19.27 ms, p<0.05). Lateral early diastolic myocardial velocity (LV-Em) was significantly lower (10.30±0.99 vs. 11.67±3.21, p<0.05) whereas lateral late diastolic myocardial velocity (LV-Am) was significantly higher than controls (11.73±1.44 vs. 8.82±1.69, p<0.05), thus a significantly lower ratio of early/late diastolic velocity at the basal segment of lateral LV (LV-Em/Am). Lower strain values at the basal lateral LV (21.39±4.12 vs. 23.78±2.02; p<0.05), mid lateral LV (21.43±4.27 vs. 23.17±1.92; p<0.05), basal septum (20.59±5.28 vs. 22.91±2.00; p<0.05), and mid septum (22.06±4.75 vs. 24.10±1.99; p<0.05) as compared to controls. SR at the basal and mid segments of the lateral LV wall and at the basal septum were also significantly lower in diabetic subjects. Strain rate (SR) in mid septal, basal and mid RV were lower than controls although not statistically significant. Patients also had significantly lower flow mediated dilatation (FMD) (8.36±4.27 vs. 10.57±4.12, p<0.05) implying endothelial dysfunction.

Strain rate in diabetic patient

Conclusion

Left ventricular strain indices are impaired in asymptomatic children and adolescents with type 1 DM despite absence of overt heart failure and normal ejection fraction. Early detection of subclinical regional myocardial dysfunction by deformation analysis including strain and strain rate may be useful in the asymptomatic diabetic population. In addition, evidence of endothelial dysfunction in the form of impaired flow mediated vasodilatation was observed in the diabetic children.

Acknowledgement/Funding

None

Systematic Review and Meta-Analysis to Establish the Association of Common Genetic Variations in Vitamin D Binding Protein With Chronic Obstructive Pulmonary Disease

Background: Vitamin-D binding protein (DBP) also known as GC protein, is a major determinant for vitamin- D metabolism and transport. GC1F, GC1S, and GC2 are the three allelic variants (denoted as rs4588 and rs7041) of GC, and known to be associated with chronic obstructive pulmonary disease (COPD). However, contradictory reports and population specific risk attributed by these alleles warranted detailed genetic epidemiology study to establish the association between GC variants and COPD. In this study we performed a meta-analysis and investigated the genetic architecture of GC locus to establish the association and uncover the plausible reason for allelic heterogeneity. Methods: Published cross-sectional case control studies were screened and meta-analysis was performed between GC variants and COPD outcome. RevMan-v5.3 software was used to perform random and/or fixed models to calculate pooled odds ratio (Meta-OR). Linkage disequilibrium (LD) and haplotypes at GC locus were evaluated using 1000 Genomes genotype data. In silico functional implications of rs4588 and rs7041 was tested using publicly available tools. Results: GC1F allele and GC1F/1F genotype were found to confer COPD risk in overall meta-analysis. GC1S/1S was found to confer risk only among Europeans. In silico investigation of rs4588 and rs7041 identified strong eQTL effects and potential role in regulation of GC expression. Large differences in allele frequencies, linkage disequilibrium (LD) and haplotypes were identified at GC locus across different populations (Japanese, African, Europeans, and Indians), which may explain the variable association of different GC alleles in different populations. Conclusion: GC1F and GC1F/1F impose significant genetic risk for COPD, among Asians. Considerable differences in allele frequencies and LD structure in GC locus may impose population specific risk.