Impact of a sustained, collaborative antimicrobial stewardship programme in spinal cord injury patients

Background

In patients with spinal cord injuries (SCIs), infections continue to be a leading cause of morbidity, mortality and hospital admission.

Objectives

This study evaluated the long-term impact of a weekly, multidisciplinary Spinal/Antimicrobial Stewardship (AMS) meeting for acute-care SCI inpatients, on antimicrobial prescribing over 3 years.

Methods

A retrospective, longitudinal, pre-post comparison of antimicrobial prescribing was conducted at our tertiary hospital in Melbourne. Antimicrobial prescribing was audited in 6 month blocks pre- (25 April 2017 to 24 October 2017), immediately post- (27 March 2018 to 25 September 2018) and 3 years post-implementation (2 March 2021 to 31 August 2021). Antimicrobial orders for patients admitted under the spinal unit at the meeting time were included.

Results

The number of SCI patients prescribed an antimicrobial at the time of the weekly meeting decreased by 40% at 3 years post-implementation [incidence rate ratio (IRR) 0.63; 95% CI 0.51-0.79; P ≤ 0.001]. The overall number of antimicrobial orders decreased by over 22% at 3 years post-implementation (IRR 0.78; 95% CI 0.61-1.00; P = 0.052). A shorter antimicrobial order duration in the 3 year post-implementation period was observed (-28%; 95% CI -39% to -15%; P ≤ 0.001). This was most noticeable in IV orders at 3 years (-36%; 95% CI -51% to -16%; P = 0.001), and was also observed for oral orders at 3 years (-25%; 95% CI -38% to -10%; P = 0.003). Antimicrobial course duration (days) decreased for multiple indications: skin and soft tissue infections (-43%; 95% CI -67% to -1%; P = 0.045), pulmonary infections (-45%; 95% CI -67% to -9%; P = 0.022) and urinary infections (-31%; 95% CI -47% to -9%; P = 0.009). Ninety-day mortality rates were not impacted.

Conclusions

This study showed that consistent, collaborative meetings between the Spinal and AMS teams can reduce antimicrobial exposure for acute-care SCI patients without adversely impacting 90 day mortality.

Duplication errors due to brand name confusion; It is not always the name-Short case series

Confusion of drug names has been identified as a leading cause of medication errors and potential iatrogenic harm. Most of these errors occur because of look-alike or sound-alike drugs. This case series gives examples of duplication errors due to brand confusion, where there are no similarities in the names.

Multimodal Precision Prevention - A New Direction in Alzheimer's Disease

At least 40% of all dementia has been linked to modifiable risk factors suggesting a clear potential for preventative approaches targeting these factors. Despite the recent promising findings from anti-amyloid monoclonal antibodies, a limited proportion of patients are expected to be eligible for these novel AD treatments. Given the heterogeneous nature of AD and the complex multi-level pathological processes leading to dementia (involving, e.g., shared risk factors, interaction of different pathology mechanisms, and their putative synergistic effects on cognition), targeting a single pathology may not be sufficient to halt or significantly impact disease progression. With exponentially increasing numbers of patients world-wide, in parallel to the unprecedented population ageing, new multimodal therapy approaches targeting several modifiable risk factors and disease mechanisms simultaneously are urgently required. Developing the next generation of combination therapies with lifestyle intervention and pharmacological treatments, implementing the right interventions for the right people at the right time, and defining accessible and sustainable strategies worldwide are crucial. Here, we summarize the state-of-the-art multimodal lifestyle-based approaches, especially findings and lessons learned from the FINGER trial, for prevention and risk reduction of cognitive impairment and dementia. We also discuss some emerging underlying biological mechanisms and the current development of precision prevention approaches. We present an example of a novel trial design combining healthy lifestyle changes with a repurposed putative disease-modifying drug and place this study in the context of the World-Wide FINGERS, the first interdisciplinary network of multimodal trials dedicated to the prevention and risk reduction of cognitive impairment and dementia.

Retrospective study of outcomes of short versus long duration of antibiotic therapy for residual osteomyelitis in surgically resected diabetic foot infection

INTRODUCTION

Optimal treatment duration for residual osteomyelitis (OM) post-amputation in diabetic foot infection (DFI) remains unclear, with resultant heterogeneity in prescribing noted in clinical practice. We aimed to identify a difference in outcomes of long duration of antibiotics (LD) with short duration (SD) in patients with culture-positive proximal bone specimen post-amputation.

METHODS

In this single-centre retrospective cohort study (Melbourne, Australia), we analysed antibiotic duration of DFI patients requiring amputation with culture-positive proximal bone specimen over a 31 month period (January 2019-September 2021). Primary outcome was reamputation or debridement at the same and/or contiguous site of amputation at 6 months. Secondary outcomes were readmission to hospital and/or recommencement of antibiotics for DFI at the same and/or contiguous site at 6 months.

RESULTS

Among 92 patients (83% male, median age 67 years), 26 received <4 weeks (SD) and 66 received ≥4 weeks (LD) antibiotic therapy. In the SD group, primary outcome occurred in 9 patients (35%) compared with 15 patients (23%) in the LD group (P = 0.246). Both secondary outcomes occurred in 12 patients (46%) in the SD group compared with 18 patients (27%) in the LD group (P = 0.086). Adjusted logistic regression analysis showed SD was not significantly associated with primary outcome [OR 1.12 (95% CI 0.38-3.31)] or secondary outcomes [OR 1.67 (95% CI 0.60-4.66)].

CONCLUSIONS

This single-centre experience did not demonstrate significant difference in outcomes between antibiotic duration of <4 weeks and ≥4 weeks in DFI patients with culture-positive proximal bone specimen post-amputation. These data provide background for larger international randomized control trials to establish optimal treatment duration.

The association between troponin level and mortality in patients admitted to hospital with acute stroke (NIHR Health Informatics Collaborative TROP-STROKE study)

Introduction

Acute stroke accounts for significant morbidity and mortality globally. The role of troponin for risk stratification in stroke is unclear.

Purpose

The aims of this study were to assess the relationship between peak troponin and mortality in patients with ischaemic stroke, haemorrhagic stroke, or subarachnoid haemorrhage and to compare this with the predictive value of first troponin or dynamic troponin change.

Methods

A retrospective cohort study was carried out using the National Institute for Health Research Health Informatics Collaborative Cardiovascular dataset of all consecutive patients who had a troponin measured at five hospitals between 2010 and 2017. Patients with at least one troponin measurement and a primary diagnosis of ischaemic stroke, haemorrhagic stroke or subarachnoid haemorrhage during a hospital admission were included. The main exposure variables were first and peak troponin, and dynamic troponin change, and the main outcome was all-cause mortality. Results were analysed using multivariable adjusted restricted cubic spline Cox regression. Survival analyses were adjusted for troponin assay, assay sensitivity (standard or highly sensitive), number of troponin measurements, age, sex, C-reactive protein level, white blood cell count, platelet count, haemoglobin, estimated glomerular filtration rate, angiography during admission, acute coronary syndrome during admission, and cardiovascular history (history of diabetes mellitus, myocardial infarction, heart failure, hypertension, stroke or atrial fibrillation). Receiver Operator Characteristic (ROC) curves were used to assess the predictive value of each exposure variable.

Results

4,712 patients were included in the analysis (ischaemic stroke: 3,346; haemorrhagic stroke: 718; subarachnoid haemorrhage: 648). Peak troponin was above the upper limit of normal in 47.4% of ischaemic stroke patients, 52.8% of haemorrhagic stroke patients, and 57.1% of subarachnoid haemorrhage patients. Patients with elevated peak troponin were older and had more cardiovascular risk factors.

A direct positive relationship was seen between peak troponin level and mortality hazard ratio in all three stroke subtypes (Figure 1). This relationship was consistent when considering dynamic troponin fold change for ischaemic or haemorrhagic stroke. For all three stroke subtypes, there was no added predictive value of peak troponin or dynamic troponin change over first troponin in predicting mortality (Figure 2).

Conclusions

A positive peak troponin was associated with increased mortality in patients presenting with ischaemic stroke, haemorrhagic stroke, or subarachnoid haemorrhage. Overall, serial troponin measurements may not improve mortality prediction beyond a single measurement. These findings may have implications for risk stratification of patients with acute stroke syndromes.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NIHR Imperial Biomedical Research Centre, as part of the NIHR Health Informatics Collaborative, and 2) British Heart Foundation

The prognostic significance of troponin level in patients with malignancy (NIHR Health Informatics Collaborative TROP-MALIGNANCY study)

Background

Cardiac troponin is commonly raised in patients with malignancy and may aid clinicians in risk prediction. The prognostic significance of raised troponin in these patients with known malignancies remains unclear.

Purpose

We sought to investigate the relation between troponin and mortality in a large, well characterised cohort of patients undergoing cardiac troponin testing with a concomitant malignancy.

Methods

A retrospective cohort study was carried out using the National Institute for Health Research Health Informatics Collaborative Cardiovascular dataset of all consecutive patients who had a troponin measured at five hospitals between 2010 and 2017. Patients with a primary inpatient diagnosis of malignancy who had at least one cTn measurement during their hospital stay were identified. Patients were classified into solid tumour or haematological malignancy subgroups. Survival analyses were performed using multivariate Cox regression analyses and Kaplan-Meier plots. Cox regression analyses were adjusted for age, gender, C-reactive protein, haemoglobin, platelet count, white cell count, acute coronary syndrome, diabetes mellitus, heart failure, chronic kidney disease, chronic obstructive pulmonary disease, atrial fibrillation and angiography. The peak cTn level (highest level measured), standardised to the upper limit of normal (ULN), was used for all analyses.

Results

5571 patients undergoing troponin testing had a primary diagnosis of malignancy and comprised of twenty-one different cancer types. 4649 patients were diagnosed with solid tumours and 922 patients were diagnosed with haematological malignancies. Patients with raised troponin had a higher burden of cardiovascular comorbidities compared to patients with a troponin level below the ULN. The median follow-up in the cohort was 14 months (interquartile range 2–39 months). At 1-year follow-up, 2495 (42%) of patients died.

Figure 1 shows Kaplan-Meier plots for patients stratified by troponin level. Patients with a troponin level ≥1xULN had a higher risk of death compared to patients with a troponin level &lt;1xULN (Figure 1A). A similar trend was shown in cancer subtypes (Figure 1B, C). Raised troponin was an independent predictor of mortality in all patients with malignancy (adjusted hazard ratio 1.66, 95% confidence interval [CI] 1.52–1.81), in solid tumours (adjusted hazard ratio 1.63, 95% CI 1.48–1.81) and in haematological malignancy (adjusted hazard ratio 1.75, 95% CI 1.44 to 2.13) when compared to patients with a troponin level &lt;1xULN.

Conclusion

A raised troponin was associated with an increased mortality risk in patients with malignancy regardless of cancer subtype. Stratification of mortality risk using troponin may help guide clinicians in making management decisions for patients with malignancy.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NIHR Imperial Biomedical Research Centre, as part of the NIHR Health Informatics Collaborative, and 2) British Heart Foundation

Developing informatics infrastructure to curate datasets using electronic health record data from five hospitals for translational cardiovascular research

Introduction

It has been challenging for researchers to access granular electronic health record (EHR) data at scale. One emerging prospect is to use big data to traverse the translational spectrum from an early discovery phase to a later implementation phase.

Purpose

To create a research-ready dataset to support translational research in cardiovascular medicine, using routinely-collected EHR data from multiple hospitals. As an early discovery phase study, we estimated the effect of invasive versus non-invasive management on the survival of patients with non-ST elevation myocardial infarction (NSTEMI) aged 80 years or older (SENIOR-NSTEMI Study). As a later implementation phase study, we determined the relationship between the full spectrum of troponin level and mortality in patients in whom troponin testing was performed for clinical purposes (TROP-RISK Study).

Methods

Using Microsoft SQL we developed a dataset of 257948 consecutive patients who had a troponin measured between 2010 and 2017 at five hospitals. We extracted phenotypically detailed data, including demographics, blood tests, procedural data, and survival status.

For the SENIOR-NSTEMI Study, eligible patients were 80 years or older who were diagnosed with NSTEMI. We estimated mortality hazard ratios comparing invasive with non-invasive management. For the TROP-RISK Study, we modelled the relation between peak troponin level and all-cause mortality using multivariable adjusted restricted cubic spline Cox regression analyses.

Results

For the SENIOR-NSTEMI Study, 1500 patients with NSTEMI were included who had a median age of 86 (interquartile range (IQR) 82–89) years of whom (845 [56%]) received non-invasive management. During a median follow-up of 3 (IQR 1.2–4.8) years, the adjusted cumulative five-year mortality was 36% in the invasive and 55% in the non-invasive group (hazard ratio 0.68, 95% confidence interval 0.55–0.84).

For the TROP-RISK Study, during a median follow-up of 1198 days (IQR 514–1866 days), 55850 (21.7%) deaths occurred. There was an unexpected inverted U-shaped relation between troponin level and mortality in acute coronary syndrome (ACS) patients (n=120049) (Figure 1A). The paradoxical decline in mortality at very high troponin levels may be driven in part by the changing case mix as troponin levels increase; a higher proportion of patients with very high troponin levels received invasive management (Figure 1B).

Conclusion

Routine EHR data can be aggregated across multiple sites to create highly granular datasets for research. The SENIOR-NSTEMI Study showed a survival advantage of invasive compared with non-invasive management of elderly patients with NSTEMI, who were underrepresented in previous trials. The inverted U-shaped relationship between troponin and mortality in ACS patients in the TROP-RISK Study demonstrates that assembling sufficiently large datasets can cast light on patterns of disease that are impossible to adequately define in single centre studies.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): 1) NIHR Imperial Biomedical Research Centre, as part of the NIHR Health Informatics Collaborative, and 2) British Heart Foundation

The association between age, troponin level, and mortality in patients hospitalised with acute pulmonary embolism (NIHR Health Informatics Collaborative TROP-PE study)

Background

A positive cardiac troponin (cTn) is an independent predictor of short-term mortality in individuals presenting with acute pulmonary embolism (PE). However, there is limited evidence regarding the impact age has on the association between cTn levels and mortality in patients with PE.

Purpose

The aim of our study was to investigate the relationship between cTn level, age, and all-cause mortality, in hospitalised patients diagnosed with an acute PE.

Methods

A retrospective cohort study using the National Institute for Health Research Health Informatics Collaborative Cardiovascular dataset of all consecutive patients who had a troponin measured at five hospitals between 2010 and 2017. Patients admitted to hospital with a primary diagnosis of PE with at least one cTn measurement were included. We modelled the relation between peak troponin level and all-cause mortality using multivariable adjusted restricted cubic spline Cox regression analyses. Effect estimates were adjusted for age, gender, high-sensitivity troponin assay, C-reactive protein, haemoglobin, platelet count, white cell count, creatinine, sodium, potassium, diabetes, hypertension, hypercholesterolaemia, acute coronary syndrome, atrial fibrillation, heart failure, acute kidney injury, chronic kidney disease, obstructive lung disease, inflammatory disorders, pneumonia and malignancy. The peak cTn level (highest level measured), standardised to the upper limit of normal (ULN), was used for all analyses.

Results

1,477 patients with at least one cTn measurement and a diagnosis of acute PE were included. During a median follow-up of 34.8 months, there were 290 (19.6%) deaths. Elevated cTn (&gt;1xULN) was associated with a hazard ratio (HR) of 3.29 (95% confidence interval [CI] 1.95–5.53) for 30-day mortality and 2.12 (95% CI 1.63–2.75) for 3-year mortality. Higher cTn levels were progressively associated with a higher mortality risk, reaching a maximum HR of 2.59 (95% CI 1.64–4.09) at 141xULN (Figure 1). Younger patients (&lt;55 years), compared with those aged over 55, had the highest 3-year HR associated with a positive cTn of 2.94 (95% CI 1.48–5.82) despite having the lowest troponin levels (mean 7.01xULN) on admission (Figure 2).

Conclusion

Elevated cTn, at all ages, is associated with an increased mortality risk in patients presenting with PE, with increasing cTn levels conferring a progressively worse long-term prognosis. Elevated cTn, no matter how small, needs to be taken seriously, particularly in young patients with an acute PE.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): 1) NIHR Imperial Biomedical Research Centre, as part of the NIHR Health Informatics Collaborative, and 2) British Heart Foundation

Coronary wave energy to predict functional recovery in patients with ischemic left ventricular dysfunction

Background

Invasive coronary angiography and non-invasive viability testing are the cornerstones of diagnosing and managing ischemic left ventricular dysfunction. At present there is no single test which serves both needs but, if developed, could revolutionise investigation of this condition. Coronary wave intensity analysis (cWIA) interrogates both contractility and microvascular physiology of the subtended myocardium [1,2] and therefore has the potential to fulfil this goal.

Objectives

We hypothesized that cWIA measured during coronary angiography would predict functional recovery with a similar accuracy to late gadolinium enhanced cardiac magnetic resonance imaging (LGE-CMR).

Methods

Patients with a left ventricular ejection fraction ≤40% and extensive coronary disease were enrolled. cWIA, fractional flow reserve and microvascular resistance were assessed with a simultaneous coronary Doppler and pressure-sensing guidewire during cardiac catheterization at rest, during hyperaemia and during low-dose dobutamine stress. Viability was assessed using LGE-CMR. Regional left ventricular function was assessed at baseline and 6-month follow up after optimization of medical therapy +/− revascularization, using transthoracic echocardiography. The primary outcome was regional functional recovery.

Results

Forty participants underwent baseline physiology, LGE-CMR and thirty had echocardiography at baseline and 6 months; 21/42 territories demonstrated functional recovery. Resting backward compression wave energy was significantly greater in recovering than non-recovering territories (−5240±3772 vs. −1873±1605 W m–2 s–1, p=0.099, Figure 1), and had comparable diagnostic accuracy to CMR (area under the curve 0.812 vs. 0.757, p=0.649, Figure 2); a threshold of −2500 W mm–2 s–1 had 86% sensitivity and 76% specificity at predicting recovery. Backward expansion wave energy did not predict recovery. FFR was numerically higher in recovering territories (0.81±0.17 vs. 0.71±0.16, p=0.058), whilst hyperaemic microvascular resistance did not differentiate recovering from non-recovering territories (1.97±0.73 vs. 2.29±1.00, p=0.287). The likelihood of functional recovery was similar in revascularised and non-revascularised territories (15/29 vs. 6/13 respectively, p=0.739). Low-dose dobutamine stress increased the energy of all waves, but did not improve the accuracy of cWIA in predicting recovery. In a regression model, resting backward compression wave energy and optimization of medical therapy predicted functional recovery; fractional flow reserve and hyperemic microvascular resistance did not.

Conclusions

Backward compression wave energy has similar accuracy to LGE-CMR in the prediction of functional recovery. cWIA has the potential to revolutionise the management of ischaemic left ventricular dysfunction, in a manner analogous to the effect of fractional flow reserve on the management of stable angina.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The British Heart Foundation Clinical Research Training Fellowship

Direct oral anticoagulants compared to vitamin K antagonists for the treatment of left ventricular thrombi

Background

Left ventricular thrombus (LVT) complicates around one in six cases of acute and chronic left ventricular systolic dysfunction and is associated with an increased risk of stroke, major systemic embolism and death, believed to be ameliorated by anticoagulation. Off-label use of direct oral anticoagulants (DOACs) for LVT has steadily increased, largely based on favourable outcomes in atrial fibrillation and venous thromboembolism, but the safety and efficacy of DOACs versus vitamin K antagonists (VKA) for LVT remains uncertain.

Purpose

The main aim of our study was to compare treatment of LVT with VKA to DOAC, focusing on all-cause mortality, stroke, major systemic emboli and major bleeding.

Methods

We conducted a retrospective observational longitudinal study of patients presenting to two large quaternary centres between 2011 and 2021 with a diagnosis of LVT. Patients were eligible if they had a documented LVT and received anticoagulation with either VKA or DOAC. Baseline data, thrombus characteristics, treatment type and duration, follow up imaging and clinical events were recorded using electronic health care records. Outcome measures included thrombus resolution, stroke and systemic embolism (SSE), major bleeding and mortality.

Results

A total of 955 patients were identified, of whom 901 received treatment with either a VKA (567 pts, 62.9%) or a DOAC (334 pts, 37.1%) and were included in the analysis. Underlying aetiologies included acute myocardial infarction (AMI) (38.3%), chronic ischaemic cardiomyopathy (38.0%) and non-ischaemic cardiomyopathy (23.7%). Rivaroxaban (43.4%) was the most frequently prescribed DOAC followed by apixaban (35.9%), and the remaining on edoxaban (20.7%). AMI related LVT was more commonly treated with DOAC (53.0%) and chronic ischaemic cardiomyopathy with VKA (72.9%).

There was a lower baseline LVEF in the VKA cohort (29.5±13.2 vs 33.1±14.2, p&lt;0.0001). Other demographic features were comparable. Median follow up was 2.5 years (IQR: 1–3.5). There were no differences in follow up duration between the two treatments (p=0.17). Greater rates of thrombus resolution were seen in the DOAC group compared to VKA (1 year: 78.4% vs 51.4%, p&lt;0.0001), with higher rates of persistent thrombus over the follow-up period seen in the VKA group (25.1% vs 12.9%, p&lt;0.0001). Rates of stroke and systemic embolization were similar between the groups (VKA 9.3% vs 9.6% DOAC, p=0.93). Higher rates of bleeding (BARC &gt;3, 8.1% VKA, 3.6% DOAC, p=0.031) (Figure 1A) and mortality (VKA 18.5%, DOAC 10.2%, p=0.001) (Figure 1B) were seen in the VKA group over the follow-up period.

Conclusions

In a large multi-centre registry of LVT of mixed aetiology, anticoagulation with DOAC was associated with earlier and greater rates of thrombus resolution and consequential reduced adverse events (major bleeding and mortality) during follow up. A funding application to support a multi-centre randomised control trial is underway.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): This work was supported by the British Heart Foundation (Fellowship FS/CRTF/21/24190 to HM) and the National Institute for Health Research (Biomedical Research Centre Award to Guy's and St Thomas' NHS FT and King's College London).

Occurrence of fumonisin-producing black aspergilli in Australian wine grapes: effects of temperature and water activity on fumonisin production by A. niger and A. welwitschiae

Black aspergilli are some of the most common mycotoxigenic fungi in vineyards worldwide. The aims of this research were to assess the occurrence of fumonisin-producing black aspergilli in Australian wine grapes and the effects of environmental factors on fumonisin production by A. niger and A. welwitschiae (syn. A. awamori). Thirty-eight Aspergillus isolates (black aspergilli) were collected from six wine grape varieties grown in Australian vineyards. LC-MS/MS analysis of culture extracts revealed that six isolates produced fumonisins FB₂ and FB₄. Molecular data revealed that all fumonisin-producing isolates were A. niger and A. welwitschiae. None of the reference isolates, A. carbonarius, A. tubingensis, A. japonicus, and A. foetidus, were positive for fumonisin production. The effects of temperature and water activity on the growth and production of fumonisins were studied using two A. niger and an isolate of A. welwitschiae on synthetic grape juice medium (SGJM) at 20 °C, 25 °C, 30 °C, and 35 °C, and 0.92 a_w, 0.95 a_w, and 0.98 a_w levels. All isolates produced FB₂ and FB₄ at 0.95 a_w and 0.98 a_w and 20 °C, 25 °C, and 30 °C. The highest growth rate observed was 14.89 mm/day for A. welwitschiae at 0.98 a_w and 35 °C, whereas the highest fumonisin production observed was 25.3 mg/kg at 0.98 a_w and 20 °C for A. welwitschiae. None of the isolates produced fumonisins at 35 °C at any water activity levels. To our knowledge, this is the first report on the occurrence of fumonisin-positive isolates of Aspergillus from Australian wine grapes and the impact of the environmental factors on fumonisin production by A. welwitschiae.

In vitro antiviral activity of medicinal mushroom Ganoderma neo-japonicum Imazeki against enteroviruses that caused hand, foot and mouth disease

Hand, foot and mouth disease (HFMD) is a highly contagious viral disease that predominantly affects children younger than 5 years old. HFMD is primarily caused by enterovirus A71 (EVA71) and coxsackievirus A16 (CV-A16). However, coxsackievirus A10 (CV-A10) and coxsackievirus A6 (CV-A6) are being increasingly reported as the predominant causative of HFMD outbreaks worldwide since the past decade. To date, there are still no licensed multivalent vaccines or antiviral drugs targeting enteroviruses that cause HFMD, despite HFMD outbreaks are still being frequently reported, especially in Asia-Pacific countries. The high rate of transmission, morbidity and potential neurological complications of HFMD is indeed making the development of broad-spectrum antiviral drugs/agents against these enteroviruses a compelling need. In this study, we have investigated the in vitro antiviral effect of 4 Ganoderma neo-japonicum Imazeki (GNJI) crude extracts (S1-S4) against EV-A71, CV-A16, CV-A10 and CV-A6. GNJI is a medicinal mushroom that can be found growing saprophytically on decaying bamboo clumps in Malaysian forests. The antiviral effects of this medicinal mushroom were determined using cytopathic inhibition and virus titration assays. The S2 (1.25 mg/ml) hot aqueous extract demonstrated the highest broad-spectrum antiviral activity against all tested enteroviruses in human primary oral fibroblast cells. Replication of EV-A71, CV-A16 and CVA10 were effectively inhibited at 2 hours post-infection (hpi) to 72 hpi, except for CV-A6 which was only at 2 hpi. S2 also has virucidal activity against EV-A71. Polysaccharides isolated and purified from crude hot aqueous extract demonstrated similar antiviral activity as S2, suggesting that polysaccharides could be one of the active compounds responsible for the antiviral activity shown by S2. To our knowledge, this study demonstrates for the first time the ability of GNJI to inhibit enterovirus infection and replication. Thus, GNJI is potential to be further developed as an antiviral agent against enteroviruses that caused HFMD.

Myocardial perfusion quantification by CMR for detection of obstructive coronary artery disease in patients with previous coronary artery bypass surgery

Funding Acknowledgements

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

Background

Coronary artery bypass grafting (CABG) is an established treatment for patients with advanced coronary artery disease (CAD). A subsequent recurrence of symptoms can cause the need for re-assessment of the coronary circulation. The accuracy of visually assessed stress perfusion cardiovascular magnetic resonance (CMR) for the detection of obstructive CAD is reduced in patients with prior CABG. In patients with complex multi-vessel CAD, myocardial perfusion quantification by CMR is superior to visual assessment (VA) for detection of obstructive disease however patients with CABG have been absent from previous studies.

Purpose

This study sought to assess the performance of myocardial perfusion quantification by CMR against invasive coronary angiography (ICA) for detecting obstructive CAD in patients with previous CABG.

Methods

Twenty-nine patients with a history of previous CABG and subsequent clinically indicated perfusion CMR study and invasive coronary angiography were recruited. Patients underwent a dual bolus stress perfusion CMR with late gadolinium enhancement (LGE) imaging at 3 Tesla. Stress myocardial blood flow (MBF) was estimated at the coronary territory level according to the AHA 16 segment model using Fermi function-constrained deconvolution. Segments with transmural LGE were excluded from MBF analysis. Stress perfusion images were analysed visually alongside LGE images and matched perfusion-LGE defects were considered negative. On ICA, coronary territories with lumen stenosis &gt;70% without an unobstructed bypass graft (&lt;70% stenosis) were considered positive.

Results

86/87 coronary territories were suitable for analysis. Sixty-five territories had at least one bypass graft including 32 territories with arterial grafts. 28/86 territories (33%) had obstructive disease on angiography. Territories with obstructive CAD had significantly lower stress MBF than unobstructed territories (1.21 [IQR: 0.96–1.45] vs 1.58 [1.40–1.84] ml/g/min, p &lt; 0.001, Figure 1). Stress MBF had good accuracy to detect coronary territories with obstructive CAD (sensitivity 71%, specificity 84%, area under the curve (AUC) 0.83, p &lt; 0.001, Figure 2A). For visual assessment, sensitivity was 79%, specificity 78% and diagnostic accuracy 78%. When analysis was confined to only territories with bypass grafts, stress MBF had 78% sensitivity, 81% specificity and AUC of 0.85, p &lt; 0.001 (Figure 2B).. In this subgroup, VA had a sensitivity of 78%, specificity of 76% and a 77% diagnostic accuracy.

Conclusions

In patients with previous surgical revascularisation, quantification of stress myocardial blood flow by CMR offers good diagnostic accuracy for the detection and localisation of anatomically significant stenoses. Accuracy is reduced compared with published data in patients without coronary grafts but remains comparable to expert visual assessment.

Prospective Evaluation of Cognitive Health and Related Factors in Elderly at Risk for Developing Alzheimer's Dementia: A Longitudinal Cohort Study

BACKGROUND

The CHARIOT PRO Main study is a prospective, non-interventional study evaluating cognitive trajectories in participants at the preclinical stage of Alzheimer's disease (AD) classified by risk levels for developing mild cognitive impairment due to AD (MCI-AD).

OBJECTIVES

The study aimed to characterize factors and markers influencing cognitive and functional progression among individuals at-risk for developing MCI-AD, and examine data for more precise predictors of cognitive change, particularly in relation to APOE ε4 subgroup.

DESIGN

This single-site study was conducted at the Imperial College London (ICL) in the United Kingdom. Participants 60 to 85 years of age were classified as high, medium (amnestic or non-amnestic) or low risk for developing MCI-AD based on RBANS z-scores. A series of clinical outcome assessments (COAs) on factors influencing baseline cognitive changes were collected in each of the instrument categories of cognition, lifestyle exposure, mood, and sleep. Data collection was planned to occur every 6 months for 48 months, however the median follow-up time was 18.1 months due to early termination of study by the sponsor.

RESULTS

987 participants were screened, among them 690 participants were actively followed-up post baseline, of whom 165 (23.9%) were APOE ε4 carriers; with at least one copy of the allele. The mean age was 68.73 years, 94.6% were white, 57.4% were female, and 34.8% had a Family History of Dementia with a somewhat larger percentage in the APOE ε4 carrier group (42.4%) compared to the non-carrier group (32.4%). Over half of the participants were married and 53% had a Bachelor's or higher degree. Most frequently, safety events typical for this population consisted of upper respiratory tract infection (10.4%), falls (5.2%), hypertension (3.5%) and back pain (3.0%). Conclusion (clinical relevance): AD-related measures collected during the CHARIOT PRO Main study will allow identification and evaluation of AD risk factors and markers associated with cognitive performance from the pre-clinical stage. Evaluating the psycho-biological characteristics of these pre-symptomatic individuals in relation to their natural neurocognitive trajectories will enhance current understanding on determinants of the initial signs of cognitive changes linked to AD.

Evaluation of a pharmacist-led penicillin allergy de-labelling ward round: a novel antimicrobial stewardship intervention

BACKGROUND

Antibiotic allergy labels (AALs), reported by up to 25% of hospitalized patients, are a significant barrier to appropriate prescribing and a focus of antimicrobial stewardship (AMS) programmes.

METHODS

A prospective audit of a pharmacist-led AMS penicillin allergy de-labelling ward round at Austin Health (Melbourne, Australia) was evaluated. Eligible inpatients with a documented penicillin allergy receiving an antibiotic were identified via an electronic medical report and then reviewed by a pharmacist-led AMS team. The audit outcomes evaluated were: (i) AMS post-prescription review recommendations; (ii) direct de-labelling; (iii) inpatient oral rechallenge referral; (iv) skin prick testing/intradermal testing referral; and (v) outpatient antibiotic allergy clinic assessment.

RESULTS

Across a 5 month period, 106 patients were identified from a real-time electronic prescribing antibiotic allergy report. The highest rate of penicillin allergy de-labelling was demonstrated in patients who were referred for an inpatient oral rechallenge with 95.2% (n = 21) successfully having their penicillin AAL removed. From the 22 patients with Type A reactions, 63.6% had their penicillin AAL removed. We demonstrated a significant decrease in the prescribing of restricted antibiotics (defined as third- or fourth-generation cephalosporins, fluoroquinolones, glycopeptides, carbapenems, piperacillin/tazobactam, lincosamides, linezolid or daptomycin) in patients reviewed (pre 42.5% versus post 17.9%, P = 0.0002).

CONCLUSIONS

A pharmacist-led AMS penicillin allergy de-labelling ward round reduced penicillin AALs and the prescribing of restricted antibiotics. This model could be implemented at other hospitals with existing AMS programmes.

Coxsackievirus A16 in a 1-Day-Old Mouse Model of Central Nervous System Infection Shows Lower Neurovirulence than Enterovirus A71

Coxsackievirus A16 (CV-A16) and enterovirus A71 (EV-A71) are the major causes of hand, foot and mouth disease in young children. Although less so with CV-A16, both viruses are associated with serious neurological syndromes, but the differences between their central nervous system infections remain unclear. We conducted a comparative infection study using clinically-isolated CV-A16 and EV-A71 strains in a 1-day-old mouse model to better understand the neuropathology and neurovirulence of the viruses. New serotype-specific probes for in situ hybridization were developed and validated to detect CV-A16 and EV-A71 RNA in infected tissues. Demonstration of CV-A16 virus antigens/RNA, mainly in the brainstem and spinal cord neurons, confirmed neurovirulence, but showed lower densities than in EV-A71 infected animals. A higher lethal dose₅₀ for CV-A16 suggested that CV-A16 is less neurovirulent. Focal virus antigens/RNA in the anterior horn white matter and adjacent efferent motor nerves suggested that neuroinvasion is possibly via retrograde axonal transport in peripheral motor nerves.

31 Understanding of Comprehensive Geriatric Assessment Among Fifth Year Medical Students

Introduction

There are 191 foundation programme jobs in geriatrics in the North East.1 Students often don’t receive teaching sessions on the comprehensive geriatric assessment (CGA). It is an assessment foundation trainees use on a daily basis on the geriatric ward and the acute take.

Methods

We designed a series of teaching sessions for fifth year medical students, delivered by different members of the multidisciplinary team. A pre- and post-session questionnaire assessed their understanding.

Results

Nine students completed the pre-session questionnaire:22% were able to define CGA11% identified the different components22% identified the target population, the benefits of CGA and the members involved44% offered solutions to obtaining a history from patients with confusion100% identified the barriers to carrying out CGA

Seven students carried out the post session questionnaire; the table below represents the number that answered correctly.

Conclusions

The majority of foundation trainees will have at least one job in geriatric medicine and participate in the acute take. The average age of hospital admissions has been rising for years,2 highlighting the importance of being able to accurately and thoroughly assess the older population. The initial questionnaire demonstrated the limited understanding that fifth year students had on the comprehensive geriatric assessment. Following sessions by different members of the MDT there was clear improvement.

The sessions covered: general overview of CGA; session by the frailty pharmacist; functional assessment by physiotherapy team; cognitive assessment by the dementia and delirium team; and life as an F1 on geriatric medicine. Positive feedback was received, emphasising the improvement in confidence in preparation for foundation training.

References

1. Oriel website: https://www.oriel.nhs.uk/Web/FND.

2. NHS digital Hospital Admitted Patient Care Activity 2015–16.

54 A Quality Improvement Project on the Recording of Stool Charts

Introduction

Change in bowel movement is a common complaint in frail patients, which can be indicative of conditions such as constipation, infection or malnutrition. Without prompt action, this can result in increased length of stay. The recording of stools can be variable. This quality improvement project was to improve stool chart completion rate and staff confidence.

Methods

We conducted two Plan-Do-Study-Act cycles over three months. We surveyed multidisciplinary staff confidence using Likert scales covering each element on the Bristol stool chart. We then reviewed patient stool charts. The first intervention was a poster. The second intervention was the addition of a sticker to the charts to help staff more easily identify them in the patient’s bedside notes. Staff-wide emails were sent to inform every one of the interventions and key stakeholders including ward managers were asked to hand this over.

Results

44 multidisciplinary staff were interviewed and 217 individual stool charts assessed over a 3 month period. 43% of stool charts were not filled in as directed after the first cycle. Posters improved staff confidence in filling out the charts from 72.3% to 92.3% after the second cycle, while 61% of stool charts came to be filled in correctly - over the initial 57%. Healthcare assistants consistently scored the highest in terms of believing charts to be up to date being whereas doctors remained the most cynical. There was little sustained change in stool chart completion rates after three PDSA cycles. Eventually, after both interventions, completion rates returned to baseline.

Conclusions

Stool chart completion rates can be improved in the short term, but sustainability is a challenge. Factors contributing to this include the variable number of agency nurses. Further improvements include teaching at the nursing induction.

Predictors of ICU admission and long-term outcomes in overdose presentations to Emergency Department

OBJECTIVE

To describe the characteristics of patients presenting to an Emergency Department (ED) following overdoses; to identify risk factors for intensive care unit (ICU) admission among these patients; and to identify the rate of mortality and repeat overdose presentations over four years.

METHODS

Adult patients presenting to ED following drug overdose during 2014 were included. Data were collected from medical notes and hospital databases.

RESULTS

During the study period, 654 patients presented to ED 800 times following overdose. Seventy-eight (9.8%) resulted in ICU admission, and 59 (7.4%) required intubation; 57.2% had no history of overdose presentations, and 72.9% involved patients with known psychiatric illness. Overdose of atypical antipsychotics (AAP), age and history of prior overdose independently predicted ICU admission. A third of patients (n = 196, 30%) had subsequent presentations to ED following overdose, in the four years from their index presentation, with an all-cause four-year mortality of 3.4% (n = 22).

CONCLUSION

A history of overdose, use of AAP and older age were risk factors for ICU admission following ED presentations. Over a third of patients had repeat overdose presentation in the four-year follow-up with a mortality of 3.4%.

Outcome of ACHD patients with non-inducible versus inducible IART undergoing cavo-tricuspid isthmus ablation: the role of empiric ablation

PURPOSE

Catheter ablation for supraventricular tachycardia (SVT) in adults with congenital heart disease (ACHD) is an important therapeutic option. Cavo-tricuspid isthmus (CTI)-dependent intraatrial re-entrant tachycardia (IART) is common. However, induction of sustained tachycardia at the time of ablation is not always possible. We hypothesised that performing an empiric CTI line in case of non-inducibility leads to good outcomes. Long-term outcomes of empiric versus entrained CTI ablation in ACHD patients were examined.

METHODS

Retrospective, single-centre, case-control study over 7 years. Arrhythmia-free survival after empiric versus entrained CTI ablation was compared.

RESULTS

Eighty-seven CTI ablations were performed in 85 ACHD patients between 2010 and 2017. The mean age of the cohort was 43 years and 48% were male. Underlying aetiology included ASD (31%), VSD (11.4%), AVSD (9.1%), AVR (4.8%), Fallot's (18.4%), Ebstein's (2.3%), Fontan's palliation (9.2%) and atrial switch (13.8%). CTI-dependent IART was entrained in 59 patients whereas it was non-inducible in 28. The latter had an empiric CTI ablation. Forty-three percent of procedures were performed under general anaesthesia. There were no reported procedural complications. There was no significant difference in the mean procedure or fluoroscopy times between the groups (empiric vs entrained CTI; 169.1 vs 183.3 and 28.1 vs 19.9 min). Arrhythmia-free survival was 64.3% versus 72.8% (p value 0.44) in the empiric and entrained groups at 21 months follow-up.

CONCLUSIONS

Long-term outcomes after empiric and entrained CTI ablation for IART in ACHD patients are comparable. This is a safe and effective therapeutic option. In the case of non-inducibility of IART, an empiric CTI line should be considered in this cohort.

2380Mechanisms of myocardial ischemia during exercise in microvascular angina

Background

Coronary microvascular dysfunction (MVD) is defined by impaired flow augmentation in response to a vasodilator, the pathophysiological basis of which is unclear. This study sought to address two major gaps in our understanding of MVD: firstly, whether diminished flow reserve is due to structural changes within the microvasculature or potentially reversible dysfunction and secondly to unravel the mechanism of exercise-induced ischemia in the absence of obstructive disease.

Methods

Simultaneous intracoronary pressure and flow velocity recordings were made in the left anterior descending artery of patients with angina and no obstructive epicardial disease (Fractional Flow Reserve >0.80). Measurements were made at rest, during adenosine-mediated hyperaemia and supine bicycle exercise. Wave intensity analysis was used to quantify waves that accelerate and decelerate coronary blood flow, coronary perfusion efficiency being defined as the proportion of total wave energy that accelerates blood flow. Patients were prospectively classified into MVD (coronary flow reserve <2.5) and controls with researchers blinded to the classification throughout the protocol. Myocardial perfusion and vascular function were assessed by 3T cardiac MRI and venous occlusion plethysmography with forearm blood flow (FBF) assessment during serial infusions of acetylcholine, adenosine and the nitric oxide synthase inhibitor NG-monomethyl-L-arginine (L-NMMA).

Results

78 patients were enrolled (42 patients had MVD and 36 were controls), with no differences in cardiovascular risk factors between groups. The MVD group had elevated coronary blood flow (21.3±6.4 vs. 15.1±4.5cm s–1; p<0.001) and global myocardial perfusion (1.36±0.37 vs. 1.13±0.22ml/min/g; p=0.01) at rest. Maximum coronary and myocardial blood flow during hyperaemia was similar in both groups. During exercise, MVD patients achieved similar peak flow (30.5±10.0 vs. 26.3±7.7cm s–1; p=0.07) despite a higher rate-pressure product (20777±5205 vs. 17450±4710bpm.mmHg; p=0.01). Coronary perfusion efficiency, decreased with exercise in the MVD group (61±11% vs. 44±10% p<0.001) but was unchanged in controls. On MRI, MVD had lower hyperaemic endo-epicardial perfusion ratio than controls (0.94±0.08 vs. 1.04±0.13; p=0.001). Augmentation of FBF with acetylcholine was attenuated in MVD patients compared to controls (p=0.02) but the response to adenosine was similar (p=0.13). Infusion of L-NMMA caused a significantly greater reduction in FBF in MVD patients compared to controls (p<0.001).

Exercise Physiology in MVD

Conclusion

Impaired flow reserve in MVD represents a dysfunctional state, characterised by inappropriately elevated resting flow due to increased nitric-oxide synthase mediated vasodilatation. There is abnormal flow distribution in the myocardium predisposing to subendocardial ischaemia, associated with and exacerbated by impaired cardiac-coronary coupling during exercise. These novel findings may represent distinct therapeutic targets.

Acknowledgement/Funding

British Heart Foundation

6029Invasive versus medical management for non-ST elevation myocardial infarction in the elderly (SENIOR-NSTEMI study)

Background

Trials and registry studies suggest lower long-term mortality after invasive than medical management among patients with non-ST elevated myocardial infarction (NSTEMI), but elderly patients were underrepresented.

Purpose

To estimate the effect of invasive compared with medical management on survival in patients with NSTEMI aged ≥80 years, using routine clinical data.

Methods

We used National Institute for Health Research Health Informatics Collaborative data to identify eligible patients admitted during 2010–2017 at five tertiary centres. We compared patients who did and did not have invasive management within 3 days of their peak troponin level. To limit the effect of immortal time bias, follow-up started 3 days after peak troponin: deaths within three days were excluded. We conducted intention-to-treat analyses.

Propensity scores were derived from a logistic regression model based on pre-treatment variables: patient demographics, blood test results, cardiovascular risk factors, history of cardiovascular disease and other comorbidities. We modelled non-linear relationships using splines. Patients with high probability (based on propensity score) of medical or invasive intervention were excluded. We used Cox models to estimate hazard ratios (HR) comparing invasive with medical management. Three methods were used to control confounding; multivariable-adjusted, multivariable-adjusted additionally for continuous propensity score (primary analysis), and inverse-probability-of-treatment (IPT) weighting. Kaplan-Meier survival curves were plotted. The robustness of the results to unmeasured confounding was assessed in sensitivity analyses.

Results

The 2,239 patients (61.3% medical management) included in analyses had a median age of 85 (IQR 82–89) years. During a median follow-up of 32.1 (IQR 11.1–54.3) months, there were 1,015 (45.3%) deaths. At 3-years, cumulative survival was 78.9% and 50.3% in the invasive and medical management groups, respectively (Figure 1).

The crude HR comparing invasive with medical management was 0.34 (95% CI 0.29–0.40). The multivariable-adjusted HR was 0.44 (95% CI 0.36–0.53), was unchanged with additional adjustment for propensity score, and was 0.46 (95% CI 0.39–0.56) in the IPT-weighted model (all p<0.0001). The E-value for the point estimate was 2.91: this implies that residual confounding could explain the association if there is an unmeasured covariate with a relative risk of at least 2.91 for both mortality and undergoing invasive management. The highest mortality HR for comorbidities included in our model were aortic stenosis 1.66 (95% CI 1.28–2.14) and obstructive lung disease 1.50 (95% CI 1.16–1.94).

Figure 1. Kaplan-Meier survival curves

Conclusion

This study provides evidence that the survival advantage from invasive management may extend to elderly patients with NSTEMI. Future research should address the possibility of unmeasured confounding, including by post-admission prognostic factors that affect choice of invasive or medical management.

Acknowledgement/Funding

Funded by NIHR Imperial Biomedical Research Centre (BRC) using NIHR Health Informatics Collaborative data service, supported by OUH, GSTT & UCLH BRCs

P4345Supporting big data research in cardiovascular medicine using routinely-collected data

Background

Many of the data points required to support translational research are collected as a matter of routine, and should be available within electronic patient records. Variations in clinical and data recording practice can mean that the extraction and standardisation of this data, with the aim of producing a large-scale, research-ready dataset, presents a number of challenges.

Purpose

We set out to create a large-scale, research-ready dataset to support translational research in cardiovascular medicine, using routinely-collected data from five large university-hospital partnerships. As an initial focus, we selected those data points that would support an investigation of the relationship between test results and outcomes in acute coronary syndrome (ACS).

Methods

The National Institute of Health Research (NIHR) Health Informatics Collaborative (HIC) is a programme of infrastructure development aimed at increasing the quality and availability of routinely-collected data for collaborative, translational research. Eighteen university-hospital partnerships signed the data sharing agreement, and are working to facilitate the sharing and re-use of data across centres, for approved research purposes.

With support from the Directors of the NIHR Biomedical Research Centres (BRCs) within five of the largest partnerships, we established a clinical data collaboration, specifying a dataset and selecting an initial research question (Figure 1). The NIHR HIC team worked to extract data against this specification. With approval from an ethics committee, and from the information governance teams at each contributing centre, data was processed by one of the centres for standardisation and analysis.

Results

The specified dataset represented a longitudinal record for patients presenting with a suspected ACS, characterised by a request for a troponin test (Figure 1). The dataset included 156 data points, grouped into demographics, cardiovascular risk factor profile, emergency department attendance and inpatient episodes, blood tests, echocardiography and mortality. Data was extracted from the records of patients for whom a troponin test was requested between 2010 and 2017. A total of 257,948 records were standardised and analysed.

The collaboration has been successful, and an initial version of the combined dataset has been created. The size of the dataset has yielded new insights into the relationship between test results and outcomes, and publications are in preparation. An expanded dataset of over 800 data points has been agreed for the next phase of the collaboration, and three other centres have joined.

Figure 1. NIHR HIC dataset generation

Conclusion

It is perfectly feasible – in terms of governance and technology – to re-use routinely-collected data for collaborative, translational research in cardiovascular medicine. The resulting dataset will be large and complex enough to require big data tools and techniques, and will yield the kind of insights afforded only by big data in medicine.

Acknowledgement/Funding

Funded by NIHR Imperial Biomedical Research Centre (BRC) using NIHR Health Informatics Collaborative data service, supported by OUH, GSTT & UCLH BRCs

2231HsCRP predicts mortality beyond troponin in 102,337 patients with suspected acute coronary syndrome (CRP-RISK study)

Background

The incremental long-term prognostic value of high-sensitivity C-reactive protein (hsCRP) above troponin in a large real-world cohort of unselected patients presenting with suspected acute coronary syndromes (ACS) is unknown.

Purpose

We hypothesised that a mildly elevated hsCRP is associated with mortality risk in patients with suspected ACS, independent of troponin level.

Methods

We used the National Institute for Health Research Health Informatics Collaborative data of 257,948 patients who had a troponin measured at 5 cardiac centres. We excluded patients with clinically abnormal white cell counts and hsCRP >15 mg/L to try limiting the population to those without overt infections, malignancies or systemic inflammatory conditions that may confound our analyses. Patients were divided into four hsCRP groups (<2, 2–4.9, 5–9.9 and 10–15 mg/L) and the association between hsCRP levels and all-cause mortality assessed.

Results

There were 102,337 patients included in the analysis (hsCRP <2 mg/L (n=38,390), 2–4.9 mg/L (n=27,397), 5–9.9 mg/L (n=26,957) and 10–15 mg/L (n=9,593)). Figure 1A displays cumulative mortality per hsCRP group, revealing increasing mortality with each consecutive group. Figure 1B further stratifies the groups according to dichotomised peak troponin level as positive or negative. This shows the greatest mortality for patients in the highest hsCRP group who also had a positive troponin assay (36.0% at 3 years).

In Cox regression analysis with time-dependent covariates, even mildly raised hsCRP was an independent predictor of mortality over time, after adjusting for age, gender, haemoglobin, white cell count, platelet count, creatinine and troponin positivity. There was a positive and graded relationship between hsCRP level and mortality at baseline, which remained at 3-years (hazard ratio (95% CI) of 1.32 (1.18–1.48) for those with hsCRP 2.0–4.9mg/L, and 1.40 (1.26–1.57), and 2.00 (1.75–2.28) for those with hsCRP 5–9.9 mg/L and 10–15 mg/L, respectively.

We explored whether inclusion of hsCRP could better reclassify the population into at-risk mortality groups. The association with 30-day, 1-year and 3-year mortality was assessed using three different risk models (model 1: age, gender, haemoglobin, creatinine; model 2: model 1 plus troponin (positivity versus negativity); model 3: model 2 plus hsCRP groups. For cumulative mortality at each time point, each successive model was better able to discriminate risk than its precursor (p<0.0001); such that inclusion of troponin and hsCRP gave the most robust risk discrimination. Model 3 achieved an AUROC >0.8 at 30 days, 1-year and 3-year mortality, surpassing the use of troponin on its own.

Figure 1. Kaplan-Meier mortality curves

Conclusions

These multi-centre, real-world data from a large cohort of patients with suspected ACS identify hsCRP as a clinically meaningful prognostic marker in addition to troponin levels and point to its potential utility in selecting patients for novel treatments targeting inflammation.

Acknowledgement/Funding

Funded by NIHR Imperial Biomedical Research Centre (BRC) using NIHR Health Informatics Collaborative data service, supported by OUH, GSTT & UCLH BRCs

P3592Troponin level and mortality risk in an unselected population of over 250,000 patients (TROP-RISK study)

Background

Current evidence suggests a direct relationship between the magnitude of troponin elevation and mortality, albeit over a limited range of troponin levels, and clinicians generally work under the impression that higher troponins signify higher mortality in all age groups.

Purpose

The objective was to use big data to determine the relationship between the full spectrum of troponin level and mortality in patients in whom troponin testing has been performed for clinical purposes.

Methods

As part of the National Institute for Health Research Health Informatics Collaborative project, all troponin values measured during the study period (2010 to 2017) were assembled from five cardiovascular centres. Troponin concentrations were standardised as a multiple of each laboratory's 99th-percentile of the upper limit of normal (ULN). All patients were followed up until death or censoring on 1st April 2017. To model the relation between peak troponin level and all-cause mortality we used restricted cubic spline Cox regression analysis. Splines were adjusted for patient age, gender, haemoglobin, creatinine, white cell count and C-reactive protein.

Results

257,948 patients underwent troponin assessment. During a median follow-up of 1,198 (IQR, 514–1,866) days, there were 55,850 (21.7%) deaths. Using multivariable-adjusted restricted cubic spline Cox regression analysis, an inverted-U shaped relationship was observed between peak troponin level and mortality in all patients (Figure 1A). Among patients who were admitted to hospital, the recorded diagnostic code was acute coronary syndrome (ACS) in 14,468 patients and non-ACS in 120,049 patients.

The revascularisation rate within 3 months was 61.0% (n=8,820) in ACS versus 4.0% (n=4,793) in non-ACS patients. There was a very different rate of revascularisation across the spectrum of troponin. The rate was only 1.4% for troponins below 1 xULN, and 6.1% between 1 and 10 xULN. Beyond 10 xULN, rate of revascularisation rose rapidly to over 85% for greater than 10,000 xULN (Figure 1B). Stratifying patients by revascularisation, the restricted cubic spline Cox regression curve showed a progressive increase in mortality within both the revascularised and non-revascularised strata, even to very high peak troponin levels (Figure 1C). Overall, revascularisation was associated with lower hazard ratios across all troponin levels. A similar pattern was seen when patients were stratified by the presence or absence of ACS diagnosis.

Figure 1. Troponin level and mortality

Conclusions

An elevated troponin, even slightly above the ULN should be taken seriously. The inverted-U shaped mortality relationship with troponin occurred because patients with the highest troponin formed a different clinical subgroup who underwent different clinical management with a high revascularisation rate. These data on troponin level and mortality may help to inform clinical practice decisions and guide future risk stratification algorithms for patients with elevated troponin.

Acknowledgement/Funding

Funded by NIHR Imperial Biomedical Research Centre (BRC) using NIHR Health Informatics Collaborative data service, supported by OUH, GSTT & UCLH BRCs

Polymeric Materials for Cell Microencapsulation

Mammalian cells have been microencapsulated within both natural and synthetic polymers for over half a century. Specifically, in the last 36 years microencapsulated cells have been used therapeutically to deliver a wide range of drugs, cytokines, growth factors, and hormones while enjoying the immunoisolation provided by the encapsulating material. In addition to preventing immune attack, microencapsulation prevents migration of entrapped cells. Cells can be microencapsulated in a variety of geometries, the most common being solid microspheres and hollow microcapsules. The micrometer scale permits delivery by injection and is within diffusion limits that allow the cells to provide the necessary factors that are missing at a target site, while also permitting the exchange of nutrients and waste products. The majority of cell microencapsulation is performed with alginate/poly-L-lysine microspheres. Since alginate itself can be immunogenic, for cell-based therapy applications various groups are investigating synthetic polymers to microencapsulate cells. We describe a protocol for the formation of microspheres and microcapsules using the synthetic polymer poly(ethylene glycol) diacrylate (PEGDA).