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 <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 <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 (>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 (<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

Clinical presentation, disease course, and outcome of COVID-19 in hospitalized patients with and without pre-existing cardiac disease: a cohort study across 18 countries

AIMS

Patients with cardiac disease are considered high risk for poor outcomes following hospitalization with COVID-19. The primary aim of this study was to evaluate heterogeneity in associations between various heart disease subtypes and in-hospital mortality.

METHODS AND RESULTS

We used data from the CAPACITY-COVID registry and LEOSS study. Multivariable Poisson regression models were fitted to assess the association between different types of pre-existing heart disease and in-hospital mortality. A total of 16 511 patients with COVID-19 were included (21.1% aged 66-75 years; 40.2% female) and 31.5% had a history of heart disease. Patients with heart disease were older, predominantly male, and often had other comorbid conditions when compared with those without. Mortality was higher in patients with cardiac disease (29.7%; n = 1545 vs. 15.9%; n = 1797). However, following multivariable adjustment, this difference was not significant [adjusted risk ratio (aRR) 1.08, 95% confidence interval (CI) 1.02-1.15; P = 0.12 (corrected for multiple testing)]. Associations with in-hospital mortality by heart disease subtypes differed considerably, with the strongest association for heart failure (aRR 1.19, 95% CI 1.10-1.30; P < 0.018) particularly for severe (New York Heart Association class III/IV) heart failure (aRR 1.41, 95% CI 1.20-1.64; P < 0.018). None of the other heart disease subtypes, including ischaemic heart disease, remained significant after multivariable adjustment. Serious cardiac complications were diagnosed in <1% of patients.

CONCLUSION

Considerable heterogeneity exists in the strength of association between heart disease subtypes and in-hospital mortality. Of all patients with heart disease, those with heart failure are at greatest risk of death when hospitalized with COVID-19. Serious cardiac complications are rare during hospitalization.

Safety of percutaneous versus transjugular liver biopsy: A propensity score matched analysis

PURPOSE

This study sought to identify the complication, mortality, and readmission rates of patients undergoing either percutaneous (PCLB) or transjugular liver biopsy (TJLB) when propensity matched for demographics and hepatic comorbidities.

METHODS

A retrospective review of New York's Statewide Planning and Research Cooperative System ICD9 coded database from the years 2009-2013 was conducted. Patients over the age of 18 undergoing either PCLB or TJLB were included. Patients with hepatic neoplasm or metastasis were excluded. 2:1 PCLB:TJLB propensity match for age, race, payment, coagulopathy, thrombocytopenia/purpura, hypercoagulability, ascites, acute liver failure, chronic hepatitis, cirrhosis, and bone marrow disease was conducted. Univariate analysis compared demographics, complications, readmissions, and mortality.

RESULTS

1467 patients met inclusion criteria (PCLB = 978, TJLB = 489). Propensity match was successful in that there were no significant differences in demographics or hepatic comorbidities. TJLB had significantly lower rates of hematoma (0.20 % vs 1.20 %, p = 0.049) and higher rates of cardiac complications (0.40 % vs 0.00 %, p = 0.045). Other complication, readmission, and mortality rates did not differ significantly. Logistic regression found no significant predictors of readmission within 7 days or any complication within 5 days.

CONCLUSION

This retrospective, multi-center database review of adult patients undergoing PCLB or TJLB propensity matched for demographics and hepatic comorbidities found that TJLB patients had a significantly higher rate of cardiac complications while PCLB patients had a significantly higher rate of hematoma. These findings support prior literature suggesting a trend towards safety of TJLB compared to PCLB in patients with hemostatic disorders and/or advanced liver disease.

CSF1R inhibitor PLX5622 and environmental enrichment additively improve metabolic outcomes in middle-aged female mice

As the elderly population grows, chronic metabolic dysfunction including obesity and diabetes are becoming increasingly common comorbidities. Hypothalamic inflammation through CNS resident microglia serves as a common pathway between developing obesity and developing systemic aging pathologies. Despite understanding aging as a life-long process involving interactions between individuals and their environment, limited studies address the dynamics of environment interactions with aging or aging therapeutics. We previously demonstrated environmental enrichment (EE) is an effective model for studying improved metabolic health and overall healthspan in mice, which acts through a brain-fat axis. Here we investigated the CSF1R inhibitor PLX5622 (PLX), which depletes microglia, and its effects on metabolic decline in aging in interaction with EE. PLX in combination with EE substantially improved metabolic outcomes in middle-aged female mice over PLX or EE alone. Chronic PLX treatment depleted 75% of microglia from the hypothalamus and reduced markers of inflammation without affecting brain-derived neurotrophic factor levels induced by EE. Adipose tissue remodeling and adipose tissue macrophage modulation were observed in response to CSF1R inhibition, which may contribute to the combined benefits seen in EE with PLX. Our study suggests benefits exist from combined drug and lifestyle interventions in aged animals.

Environmental enrichment improves metabolic and behavioral health in the BTBR mouse model of autism

BTBR T + Itpr3tf/J (BTBR) mice are an Autism Spectrum Disorder (ASD)-like model that exhibit behavioral and physiological deficits similar to those observed in patients with ASD. While behavioral therapy is a first line of treatment in ASD patients, comparable non-pharmacological treatments are less explored in murine models. Here, we administer a bio-behavioral intervention for BTBR mice by way of environmental enrichment (EE) - an experimental housing paradigm previously shown to improve systemic metabolism, learning/memory, anxious behavior, neurogenesis, locomotion, and immunocompetence in C57BL/6 mice. Juvenile BTBR mice were randomized to standard or EE housing and were subjected to metabolic and behavioral assessments up to 17 weeks. Following EE exposure, we report an EE-induced metabolic and behavioral phenotype. Male BTBR mice responded metabolically to EE, displaying reduced adiposity, increased lean mass, improved glycemic control, and decreased circulating leptin. The gene expressions of brain-derived neurotrophic factor (Bdnf) and its receptor (Ntrk2/TrkB) were upregulated in several brain areas in EE-BTBR males. EE-BTBR females showed modest reduction of adiposity and no changes in glycemic control, circulating leptin, or Bdnf/Ntrk2 gene expression. With regard to behavior, EE resulted in decreased anxiety, and increased social affiliation. Together, these results suggest that EE improves metabolic and behavioral health in BTBR mice.

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

Long-term environmental enrichment affects microglial morphology in middle age mice

Aging is associated with increased central nervous system inflammation, in large part due to dysfunctional microglia. Environmental enrichment (EE) provides a model for studying the dynamics of lifestyle factors in the development of age-related neuroinflammation and microglial dysfunction. EE results in improvements in learning and memory, metabolism, and mental health in a variety of animal models. We recently reported that implementing EE in middle age promotes healthy aging. In the present study, we investigated whether EE influences microglial morphology, and whether EE is associated with changes in expression of microglial and neuroinflammatory markers. Inflammatory cytokines and MHC-II were reduced following 12-month EE in 10-month-old mice. Long-term EE for 7.5 months resulted in broad increases in Iba1 expression in hippocampus, hypothalamus, and amygdala detected by immunohistochemistry. Quantification of microglial morphology reveal both hypertrophy and ramification in these three brain regions, without increases in microglial cell density. These data indicate that long-term EE implemented in middle age results in a microglial state distinct from that of normal aging in standard laboratory housing, in specific brain regions, associated with reduced neuroinflammatory markers and improvement of systemic metabolism.

A study of electron and thermal transport in layered titanium disulphide single crystals

We present a detailed study of thermal and electrical transport behavior of single crystal titanium disulphide flakes, which belong to the two dimensional, transition metal dichalcogenide class of materials. In-plane Seebeck effect measurements revealed a typical metal-like linear temperature dependence in the range of 85-285 K. Electrical transport measurements with in-plane current geometry exhibited a nearly T ² dependence of resistivity in the range of 42-300 K. However, transport measurements along the out-of-plane current geometry showed a transition in temperature dependence of resistivity from T ² to T ⁵ beyond 200 K. Interestingly, Au ion-irradiated TiS₂ samples showed a similar T ⁵ dependence of resistivity beyond 200 K, even in the current-in-plane geometry. Micro-Raman measurements were performed to study the phonon modes in both pristine and ion-irradiated TiS₂ crystals.

Medical students' personal experience of high-stakes failure: case studies using interpretative phenomenological analysis

BACKGROUND

Failing a high-stakes assessment at medical school is a major event for those who go through the experience. Students who fail at medical school may be more likely to struggle in professional practice, therefore helping individuals overcome problems and respond appropriately is important. There is little understanding about what factors influence how individuals experience failure or make sense of the failing experience in remediation. The aim of this study was to investigate the complexity surrounding the failure experience from the student's perspective using interpretative phenomenological analysis (IPA).

METHODS

The accounts of three medical students who had failed final re-sit exams, were subjected to in-depth analysis using IPA methodology. IPA was used to analyse each transcript case-by-case allowing the researcher to make sense of the participant's subjective world. The analysis process allowed the complexity surrounding the failure to be highlighted, alongside a narrative describing how students made sense of the experience.

RESULTS

The circumstances surrounding students as they approached assessment and experienced failure at finals were a complex interaction between academic problems, personal problems (specifically finance and relationships), strained relationships with friends, family or faculty, and various mental health problems. Each student experienced multi-dimensional issues, each with their own individual combination of problems, but experienced remediation as a one-dimensional intervention with focus only on improving performance in written exams. What these students needed to be included was help with clinical skills, plus social and emotional support. Fear of termination of the their course was a barrier to open communication with staff.

CONCLUSIONS

These students' experience of failure was complex. The experience of remediation is influenced by the way in which students make sense of failing. Generic remediation programmes may fail to meet the needs of students for whom personal, social and mental health issues are a part of the picture.

Tailoring the endovascular management of transplant renal artery stenosis

In this study we analyze the different types of endovascular interventions (EVIs) in de novo transplant renal artery stenosis (TRAS) and its anatomical subtypes to examine any variation in recovery of allograft function, blood pressure control, EVI patency and allograft survival with respect to EVI type (DES: drug-eluting stent, BMS: bare-metal stent, PTA: percutaneous transluminal angioplasty). Forty-five patients underwent a total of 50 primary EVIs (DES: 18, BMS: 26, PTA: 6). Patients were stratified according to medical co-morbidities, graft characteristics, biopsy results, clinical presentation and TRAS anatomic subtypes (anastomotic: 26, postanastomotic: 17, bend-kink: 2). There was significant improvement in allograft function and mean arterial blood pressure (MAP) control across all interventions (pre-EVI-creatinine [CR]: 2.8 ± 1.4, post-EVI-Cr: 2.1 ± 0.7, p < 0.001; pre-EVI-MAP: 117 ± 16, post-EVI-MAP: 112 ± 17, p = 0.03) with no significant difference among EVI types. There was no significant difference in allograft survival with respect to EVI type. Patency was significantly higher in EVIs performed with DES and BMS compared to PTA (p = 0.001). In the postanastomotic TRAS subtype, patency rates were significantly higher in DES compared to BMS (p = 0.012) in vessels of comparable reference diameter (≤5 mm).

Stakeholder involvement in designing an oral care training package for care home staff

This paper describes the principles applied and the challenges met while seeking user and other stakeholder perspectives before designing an oral care training package for carers in nursing and residential care facilities. The public health competencies it illustrates include the application of appropriate leadership styles, strategic management, collaborative working and knowledge of research methodology.

The use of dental therapists as examiners in dental epidemiological surveys

Practitioners in Dental Public Health often need to find more cost-efficient ways of providing services, whilst assisting with the personal and professional development of colleagues. This paper gives an example of how these competencies were deployed in relation to an epidemiology programme.

Evolution of segmental anesthesia for Laparo-Endoscopic Single Site (LESS) cholecystectomy

AIM

Transumbilical Laparo-Endoscopic Single Site (LESS) surgery promises improved cosmesis, quick recovery, reduced postoperative pain and shorter length of hospital stay. Since only a simple umbilical incision is used, LESS surgery can be completed with segmental epidural anesthesia. This study describes the evolution of our technique of LESS cholecystectomy from a combination of spinal and epidural anesthesia to thoracic epidural alone and presents our experience with its safety, the observed morbidity, and the reported patient satisfaction.

METHODS

In August 2009, a prospective evaluation of LESS cholecystectomy with regional anesthesia was undertaken. We recruited patients with chronic cholecystitis or symptomatic cholelithasis. Blood loss, operative time, complications, and length of hospital stay were measured. Preoperatively and 14 days postoperatively, outcome and symptom resolution were scored.

RESULTS

Fifteen consecutive patients underwent LESS cholecystectomy; first with combined spinal-epidural (CSE), and then with thoracic epidural anesthesia alone. Immediate postoperative pain and discomfort were well tolerated. VAS scores upon admission to PACU were 0.4 (1.7±2.2). At postoperative day 14, the patients scored high values for "Satisfaction", 10 (10±1.0) and "Cosmesis", 10 (9.3±1.5).

CONCLUSION

LESS cholecystectomy with epidural anesthesia can be undertaken safely. Patient satisfaction and cosmesis are particularly prominent amongst our patients. Our experience supports further utilization of epidural anesthesia for selected patients undergoing LESS cholecystectomy.

Cyclin D1 and p16 expression in pleomorphic adenoma and carcinoma ex pleomorphic adenoma of the parotid gland

AIMS

To compare cyclin D1 and p16(ink4) (p16) expression in normal tissue, pleomorphic adenoma (PA) and carcinoma ex pleomorphic adenoma (CXPA) of the parotid gland.

METHODS AND RESULTS

Immunohistochemistry was used to examine cyclin D1 and p16 expression in 43 parotid tumours (29 PAs and 14 CXPAs). Cyclin D1 and p16 were both significantly more likely to be expressed in the neoplastic than in the normal epithelial and stromal components of PA and CXPA (P < 0.001 and P < 0.005, respectively). Cyclin D1 was more likely to be expressed in the malignant components of CXPA than in the benign components of PA (50% versus 31% and 31%, respectively), but the trend was not statistically significant. There was no evidence of this association for p16 (corresponding positivity rates 69% versus 81% and 52%).

CONCLUSIONS

Our findings provide preliminary evidence of roles for cyclin D1 and p16 in the development of PA and for cyclin D1 in the progression of PA to CXPA.

Cyclin A expression and its diagnostic value in pleomorphic adenoma and carcinoma expleomorphic adenoma of the parotid gland

AIMS

To investigate cyclin A expression in pleomorphic adenoma (PA) and carcinoma expleomorphic adenoma (CXPA) of the parotid gland with a view to assessing its potential value as a diagnostic marker for CXPA.

METHODS AND RESULTS

Cyclin A expression in PA and CXPA was studied using semiquantitative immunohistochemistry. The epithelial component of the tumours expressed cyclin A in a statistically significantly (P < 0.005) higher number of CXPA cases (86%) compared with the PA cases (39%). Cyclin A was not expressed in normal salivary tissues of PA and CXPA.

CONCLUSIONS

High cyclin A expression is a useful marker for the pathological diagnosis of CXPA.

Acquired haemophilia heralded by bleeding into the oral mucosa in a patient with bullous pemphigoid, rheumatoid arthritis, and vitiligo

Acquired haemophilia is rare and potentially fatal, with a mortality of 20% if left untreated. There is a strong association with other autoimmune diseases. This report describes a patient with rheumatoid arthritis, vitiligo, and bullous pemphigoid where the diagnosis of acquired haemophilia was made after an extensive bleed into a bullous lesion in the buccal mucosa. This case highlights some of the potential complications of acquired haemophilia and its treatment.

Patient burden of centralization of head and neck cancer surgery

This study was undertaken to assess the impact on patients of proposals to centralize head and neck oncology services in the UK. A retrospective audit of the 2001–2002 head and neck cancer database at South Devon district general hospital identified 85 patients (50 males: 35 females; median age 66 years; range 29–93) diagnosed with head and neck cancer. The total number of hospital visits for diagnostic, therapeutic and other management services were recorded (median number of visits 28; range 1–78). Using this data, the extra distance required to travel to a potential regional cancer centre located in Bristol during the first six months of management was extrapolated. It was calculated that each patient would have to travel on average an extra 5333 miles (median 5658; range 185–13 759). Published documents advocating centralization of oncology services make no reference to the patient burden of geographic relocation of medical services. Agencies involved with restructuring oncology services must recognize the non-clinical impact of centralization and make some provision to overcome the burden facing patients and their carers.

Yield of colonoscopy in patients with nonacute rectal bleeding: a multicenter database study of 1766 patients

OBJECTIVE

There are few data to guide the choice between colonoscopy and flexible sigmoidoscopy in patients with nonacute rectal bleeding, especially in younger age groups. Our aim was to determine the yield of colonoscopy for significant proximal large bowel disease in the absence of significant distal disease, with special reference to young patients.

METHODS

This was a retrospective study of data collected prospectively in 1766 patients (median age 57 yr, 711 women). The endoscopic database (GI-Trac) contained 152 discrete fields for data input. Multiple logistic regression analysis was performed to identify variables independently associated with the presence of isolated significant proximal disease.

RESULTS

Young patients had a higher percentage of normal examinations than did older patients. The incidence of diverticular disease, small polyps, large polyps, and cancer rose with increasing age. No patient aged <40 yr had an isolated proximal cancer, but 7% had other significant isolated proximal disease. There was no overall association between age and significant proximal disease in the absence of significant distal disease (p = 0.66). The only variable associated with isolated proximal disease was anemia (odds ratio = 1.81; 95% CI = 1.11-2.93; p = 0.02).

CONCLUSION

The yield of colonoscopy (beyond the range of sigmoidoscopy) for neoplasia is low in patients aged <40 yr, but other significant disease may be missed if age is the only criterion determining colonoscopy use.

The utility of EUS and EUS-guided fine needle aspiration in detecting celiac lymph node metastasis in patients with esophageal cancer: a single-center experience

BACKGROUND

The aims of this study were to determine the utility of EUS and EUS-guided fine needle aspiration (EUS-FNA) in the detection and confirmation of celiac lymph node metastasis in patients with esophageal cancer and to define EUS features predictive of celiac lymph node metastasis in these patients.

METHODS

The records of 211 patients with esophageal cancer who underwent EUS staging were reviewed. The operating characteristics of EUS were determined in patients where either surgery, EUS-FNA of a celiac lymph node, or both were performed (n = 102). The association between selected variables and the presence of celiac lymph node metastasis was evaluated by univariate and multivariable analyses.

RESULTS

EUS in 48 patients provided a true-positive diagnosis of celiac lymph node involvement, a false-positive and false-negative result, respectively, in 6 and 14 patients, and a true-negative diagnosis in 34 patients. The sensitivity of EUS in detecting celiac lymph node was 77% (95% CI [67, 88]), specificity 85% (95% CI [74, 96]), negative predictive value 71% (95% CI [58, 84]), and the positive predictive value 89% (95% CI [81, 97]). EUS-FNA was performed in 94% (51/54) of patients with celiac lymph nodes. The accuracy of EUS-FNA in detecting malignant celiac lymph nodes was 98% (95% CI [90, 100]). Advanced T-stage, the need for dilation, detection of peritumoral lymph nodes, and black race were associated with celiac lymph node involvement. In multivariable analysis, advanced T-stage was the strongest predictor of celiac lymph node involvement.

CONCLUSION

EUS and EUS-FNA are highly accurate in detecting and confirming celiac lymph nodes metastasis. Depth of tumor invasion as assessed by EUS is a strong predictor of celiac lymph node metastasis in patients with esophageal cancer.

Most patients overdose on topical nasal corticosteroid drops: an accurate delivery device is required

Otolaryngologists and general practitioners commonly prescribed intranasal corticosteroid drops for rhinitis. Compliance in real patients has not previously been studied, but is generally believed to be poor. Recent concerns over systemic adverse effects of topical corticosteroids have highlighted the risks of overdosing. Fifty patients, who were prescribed betamethasone, were prospectively studied for accuracy of compliance using a weighed dose study. Patients consistently administered inaccurate quantities of nasal corticosteroid drops, with a marked tendency to overdose up to four times the recommended daily dose (RDD) in some cases. The mean dose administered was 200 per cent of the RDD. Of the 50 patients, only seven (14 per cent) administered the correct dose. The introduction of metered-dose delivery systems should be considered to reduce the risk of inadvertent overdosing.

Preliminary results of a pilot study investigating the potential of salivary cortisol measurements to detect occult adrenal suppression secondary to steroid nose drops

Adrenocortical suppression is a well-known risk of systemic steroids, but is thought less likely to occur with topical intranasal corticosteroids. However, the UK Committee on the Safety of Medicines (UKCSM) has expressed concern about the possibility of this complication. We assessed the prevalence of adrenal suppression in patients with rhinitis using intranasal beclomethasone and betamethasone; and the potential value of salivary cortisol as a tool for detecting this complication. Sixty-six patients (38 men: 28 women; mean age 49.6[SD 16.0] years) were prospectively screened for adrenal insufficiency using clinical assessment and salivary cortisol measurements. Abnormalities at this initial screening were confirmed with a Short Synacthen Test (SST). No patient was clinically Cushingoid. All 22 beclomethasone users had normal salivary cortisols. Eleven (25%) of 44 patients using betamethasone had subnormal salivary cortisol levels (mean morning cortisol 2.8[SD 0.9]nmol/l) suggesting adrenal suppression, which was confirmed by an impaired SST in each case. The positive predictive value of salivary cortisol measurements was 100%. Only patients with abnormal salivary cortisols had a SST, so no comment can be made about sensitivity/specificity. Topical betamethasone may produce occult adrenal insufficiency and assessment of adrenal function is recommended in these patients. Measurement of salivary cortisol is a useful, non-invasive and economical test for monitoring patients using intranasal corticosteroids.

MR imaging of the Achilles tendon: overlap of findings in symptomatic and asymptomatic individuals

OBJECTIVE

To differentiate MR imaging characteristics of symptomatic as compared with asymptomatic Achilles tendons.

DESIGN

1.5 T MR images of 94 feet (88 patients) with "abnormal" MR examinations were retrospectively evaluated and clinically correlated. Two masked, independent observers systematically evaluated for intratendon T2 signal, tendon thickness, presence of peritendonitis, retrocalcaneal bursal fluid volume, pre-Achilles edema, bone marrow edema at the Achilles insertion, and tears (interstitial, partial, complete). These findings were correlated with symptoms (onset and duration) and physical examination results (tenderness, palpable defects, increased angle of resting dorsiflexion).

RESULTS

Of the 94 ankles, 64 ankles (32 females, 29 males) were clinically symptomatic. No relationship between Achilles tendon disorders and age or gender was identified. Asymptomatic Achilles tendons frequently demonstrated mild increased intratendon signal (21/30), 0.747 cm average tendon thickness, peritendonitis (11/30), pre-Achilles edema (12/30), and 0.104 ml average retrocalcaneal bursal fluid volume. Symptomatic patients had thicker tendons (0.877 cm), greater retrocalcaneal fluid volume (0.278 ml), more frequent tears (23/64), a similar frequency of peritendonitis (22/64) but less frequent pre-Achilles edema (18/64). Sixty-four percent of the Achilles tendon tears were interstitial. Except for two interstitial tears in control patients, the majority of Achilles tears were in symptomatic patients (14/16). Only symptomatic tendons demonstrated partial or complete tendon tears. In addition, calcaneal edema was found almost exclusively in actively symptomatic patients. Thicker tendons were associated more often with chronic symptoms and with tears. When present in symptomatic patients, peritendonitis was usually associated with acute symptoms. The presence of pre-Achilles edema, however, did not distinguish acute from chronic disorders.

CONCLUSION

There is significant overlap of MR findings in symptomatic and asymptomatic Achilles tendons. Furthermore, there is apparently a spectrum of disease in symptomatic tendons ranging from subtle intratendinous and peritendinous signal to partial and complete tendon tear.

Powered laryngeal shavers and laryngeal papillomatosis: a preliminary report

Carbon dioxide (CO2) laser ablation is widely accepted as the most effective first line surgical treatment of recurrent laryngeal papilloma. However, vaporization of papilloma with the CO2 laser exposes the patient and staff to a potentially infective plume. Furthermore, unsuitable pathological tissue specimens and scarring of the surrounding laryngeal architecture are inevitable consequences of the thermal energy generated by this instrument. Following their innovative use in endonasal surgery, powered laryngeal microresecting instruments (Xomed Shavers) have been developed for laryngeal surgery. We assessed the value of these new instruments in five patients who had previously undergone laser ablation. All of the patients reported that their postoperative recovery was the 'same as' or 'better than' that following laser surgery. The surgeon reported that though there was more bleeding, shaver excision of papilloma provided good clearance of disease; easy collection of pathological samples; and a potentially safer and faster alternative to laser excision.

Incidence and clinical significance of frontal sinus or orbital entry during pterional (frontotemporal) craniotomy

BACKGROUND AND PURPOSE

Frontal sinus entry, orbital entry, or both may occur during pterional craniotomy for microsurgical clipping of aneurysms. We sought to determine the incidence and clinical significance of these findings on postoperative CT scans.

METHODS

Eighty-two postoperative CT scans of the head obtained from 81 patients (64 women, 17 men; age range, 25-80 years) were retrospectively reviewed over a 1-year period. These scans were reviewed independently by two blinded neuroradiologists for the presence and degree of orbit and frontal sinus entry that may have occurred during craniotomy. Clinical charts, operative notes, and discussions with the patients' neurosurgeons were reviewed to determine the clinical management and significance of these findings.

RESULTS

Of the total 82 craniotomies reviewed, 77 (94%) had been performed via the pterional approach (43 right, 34 left). Twenty-three (30%) of these 77 studies revealed some evidence of penetration into the orbit or frontal sinus (orbit=65.2% [15/23]; frontal sinus=30.4% [7/23]; both=4.4% [1/23]). Only five of 16 patients with radiographic orbital penetration had evidence of involvement of intraorbital contents (ie, thickened lateral rectus, fat herniation, intraorbital air). Chart review revealed no complication or change in management. Of the seven patients with frontal sinus entry, three had mucosal exenteration and packing with antibiotic-coated gelfoam. No delayed complications (ie, persistent fever, mucocele, cerebrospinal fluid leak, air leak, or meningitis) were identified (follow-up period, 18-29 months).

CONCLUSION

Frontal sinus or orbital entry is not uncommon after pterional craniotomy, but the incidence of immediate complications is rare.

One stop breast clinics--victims of their own success? A prospective audit of referrals to a specialist breast clinic

AIMS

We aimed to assess the number of unnecessary referrals to a specialist breast clinic, with special reference to urgent referrals, and to compare referrals with published guidelines for referral to these clinics.

METHODS

We carried out a prospective audit of new patient referrals from primary care to a specialist breast clinic. We assessed the total number of referrals, proportion of urgent and non-urgent referrals, proportion of unnecessary referrals according to published guidelines, waiting times for outpatient appointments and outcomes for these patients.

RESULTS

Of the total of 321 referrals, 35% were urgent. Twenty-eight per cent of urgent referrals and 37% of non-urgent were inappropriate according to published guidelines. Ten per cent of referrals had breast cancer while 90% had benign disease or no pathology.

CONCLUSIONS

There is a proliferation of guidelines (NHS, SIGN, BASO, Patients' Charter) for the organization of specialist breast clinics with the aim of providing rapid diagnosis for patients with malignant disease, or reassurance for symptomatic patients that they do not have breast cancer. However increasing numbers of patients are being referred to these clinics with minimal or no pathology, and this is not acknowledged by these guidelines. In this prospective study of referrals from primary care to a specialist breast clinic, one-third of referrals were inappropriate and this inevitably reduced the efficiency of the service provided for patients with significant symptoms.

Irreversible spinal cord injury as a complication of subarachnoid ethanol neurolysis

Subarachnoid neurolysis using ethanol to destroy selectively the posterior roots of the spinal cord is a method for providing pain relief in patients with advanced cancer. Weakness of the extremities is a complication of the procedure that has been attributed to spread of the neurolytic agent to the anterior roots. The authors provide evidence of spinal cord injury as a cause of lower extremity weakness in a patient after subarachnoid ethanol neurolysis.

Technical issues for MRI examination of the posterior fossa

Examination of the posterior fossa by magnetic resonance imaging is discussed with respect to modern techniques and equipment, and including recent results of non-conventional studies in multiple sclerosis. Optimal protocol design will maximize resolution and signal strength while providing diagnostic contrast. Motion artifact from the sigmoid and transverse sinuses may appear as ghosting and can be mitigated with proper imaging parameter choices.

Celiac disease and recurrent pancreatitis

BACKGROUND

Celiac disease is associated with pancreatico-biliary disease. Postulated mechanisms include reduced gallbladder emptying due to impaired cholecystokinin release and pancreatitis due to malnutrition. We hypothesize that celiac disease may also be associated with pancreatico-biliary abnormalities due to duodenal inflammation and papillary stenosis.

METHODS

Over a 48-month period, 169 patients referred for possible sphincter of Oddi dysfunction who underwent pancreatico-biliary manometry were tested for gliadin and endomysial antibodies. Duodenal and papillary biopsies were preformed in those patients who were positive.

RESULTS

Celiac disease was diagnosed in 12 (7.1%; 3 men, 9 women). The mean age was 61 years as compared with 37 years for those patients without celiac disease. All of the celiac patients had been referred for recurrent abdominal pain and/or idiopathic pancreatitis. Ten had idiopathic recurrent pancreatitis with elevated amylase and lipase levels. Two of these patients also had mildly elevated liver function tests associated with the abdominal pain. Only 3 of 12 patients had a prior diagnosis of celiac disease. These 12 patients had manometric evidence of stenosis and histologic evidence of periampullary inflammation as well as histologic changes consistent with celiac disease. In 10 of 12 patients sphincterotomy or extension of a prior papillotomy was performed. Two patients were treated with a gluten-free diet alone.

CONCLUSIONS

We describe 12 patients with papillary stenosis and celiac disease. In 9 cases the celiac disease was a new diagnosis. Celiac disease should be considered in the etiology of papillary stenosis or idiopathic recurrent pancreatitis.

The sensory somatotopic map of the human hand demonstrated at 4 Tesla

Recent attempts at high-resolution sensory-stimulated fMRI performed at 1.5 T have had very limited success at demonstrating a somatotopic organization for individual digits. Our purpose was to determine if functional MRI at 4 T can demonstrate the sensory somatotopic map of the human hand. Sensory functional MRI was performed at 4 T in five normal volunteers using a low-frequency vibratory stimulus on the pad of each finger of the left hand. A simple motor control task was also performed. The data were normalized to a standard atlas, and individual and group statistical parametric maps (SPMs) were computed for each task. Volume of activation and distribution of cluster maxima were compared for each task. For three of the subjects, the SPMs demonstrated a somatotopic organization of the sensory cortex. The group SPMs demonstrated a clear somatotopic organization of the sensory cortex. The thumb to fifth finger were organized, in general, with a lateral to medial, inferior to superior, and anterior to posterior relationship. There was overlap in the individual SPMs between fingers. The sensory activation spanned a space of 12-18 mm (thumb to fifth finger) on the primary sensory cortex. The motor activation occurred consistently at the superior-most extent of the sensory activation within and across subjects. The sensory somatotopic map of the human hand can be identified at 4 T. High-resolution imaging at 4 T can be useful for detailed functional imaging studies.

Mapping of secondary somatosensory cortex activation induced by vibrational stimulation: an fMRI study

Sensory functional MRI was performed in seven normal volunteers at 1. 5 T using a vibratory stimulus applied to the pad of the first finger of the left hand. The data was normalized to a standard atlas, and individual and group statistical parametric maps were computed. Robust bilateral activation was demonstrated in the secondary somatosensory cortex (SII), indicating a bilateral representation of SII in humans. Greater maxima and activation volumes were achieved in contralateral SII as compared to SI. Sensory fMRI can provide a sensitive assay for probing the nature and function of SII in vivo.

Cerebral neoplasms in adults

MRI plays a critical role in the diagnosis, management, and follow-up of adult supratentorial neoplasms. However, there is considerable overlap in the imaging findings of these lesions. New imaging methods, such as functional MRI, diffusion imaging, and spectroscopy may further improve diagnostic specificity and surgical management. Knowledge of the pathogenesis of these tumors, imaging characteristics, and available novel imaging tools will aid the radiologist in making meaningful contributions in the evaluation and treatment of these lesions.

Blood ordering practices in elective and emergency surgical procedures

A retrospective study of preoperative blood ordering practices for 20 commonly performed elective and emergency general surgical procedures was carried out in a Glasgow teaching hospital. It was found that 50.6% of cross-matched blood was returned unused. This practice contributes to the wasteful outdating of blood held in cross match status but never used. As a result, the Minimum Blood Ordering Schedule has been developed to guide blood ordering in those operations where there is a realistic probability of transfusion (<30 %), and a group and screen is advocated for the remainder of procedures. In this way significant savings can be made in blood, laboratory technician's time and resources.

Biomechanical and sensory parameters of the human esophagus at four levels

The biomechanical and sensory characteristics of the lower esophageal sphincter (LES) and those of the striated and smooth muscle portions of the esophagus have not been compared in humans. Our aim was to determine sensory perception, cross-sectional area (CSA), and biomechanical parameters at different levels of the esophagus. We studied 11 healthy volunteers, using impedance planimetry. Intermittent balloon distensions (5-60 cmH2O) were performed at four sites: 1) the LES, 2) 5 cm above LES (distal), 3) 10 cm above LES (mid), and 4) 5 cm below the upper esophageal sphincter (proximal). During these distensions, CSAs, biomechanical parameters, and sensory responses were measured. The mid-esophagus had a higher (P < 0.05) CSA than the distal esophagus. The LES had the smallest CSA (P < 0.05). The LES and the proximal esophagus had greater (P < 0.05) wall tension and were less (P < 0.05) deformable than the mid- or distal esophagus. Sensory thresholds were lower (P < 0.05) in the proximal compared with the mid- or distal esophagus. Biomechanical and sensory parameters are not uniform along the length of the esophagus. The striated muscle portion is more sensitive and less compliant than the smooth muscle portion. These differences could affect the results of balloon distension tests of the esophagus.

How useful are manometric tests of anorectal function in the management of defecation disorders?

OBJECTIVES

The clinical usefulness of assessing anorectal physiology has not been systematically examined. Our aims were to evaluate whether manometric tests of anorectal function influence the management and outcome of patients with defecation disorders, and to identify the patients who may most benefit from this assessment.

METHODS

Using a standard protocol of anorectal manometry rectal sensation, saline continence, simulated defecation, and pudendal nerve terminal latency tests, we studied 143 consecutive patients (m/f = 27/116) and followed their progress over 18 months.

RESULTS

Tests of anorectal function in 126 (88%) patients revealed new information that led to a change in the management of 108 (76%) patients. Among 69 patients referred with constipation, 33 (48%) had obstructive defecation, and 40 (58%) had impaired rectal sensation; 30 (43%) improved after biofeedback therapy. Among 56 patients referred with fecal incontinence, 55 (98%) had manometric abnormalities: 30 (53%) had a low squeeze sphincter pressure, 20 (36%) had impaired rectal sensation, and 28 (50%) had pudendal neuropathy. Thiry-four (60%) patients were referred for biofeedback therapy and 11 (20%) for surgery. Of these 15 completed biofeedback therapy with improvement, and six had successful surgery. Seven of 10 (70%) patients referred for preoperative evaluation had abnormalities that contraindicated surgery.

CONCLUSIONS

Manometric tests of anorectal function provide not only an objective diagnosis but, also, a better understanding of the underlying pathophysiology. In addition, it provides new information that could influence the management and outcome of patients with disorders of defecation.

Organization of the fibronectin gene provides evidence for exon shuffling during evolution

We report the organization of the two ends of the rat fibronectin gene which encode the type I and II repeating units of the protein. We show that each of these modular structural units is encoded by a separate exon. Homologous type I and II repeats are known to occur in tissue plasminogen activator, factor XII and a bovine seminal plasma protein. Comparison of these sequences and the exon structures of the fibronectin and tissue plasminogen activator genes indicates that exons encoding type I and type II repeats have reassorted during evolution. We also report analyses of the extreme 5' and 3' ends of the fibronectin gene including the promoter region and the exon encoding the prepro sequence of fibronectin and we show that the gene is transcribed from a single initiation site to a single polyadenylation site. These data provide information pertinent to the transcriptional regulation of the gene, the alternative splicing of the primary transcript and the structure of the primary translation product.

Multiple sites of alternative splicing of the rat fibronectin gene transcript

We describe analyses of the structure and expression of the rat fibronectin gene with particular attention to the 40-kb stretch from the center of the gene which encodes 17 type-III repeating units. Each repeat is precisely separated from its neighbors by introns and most are encoded by pairs of exons. Three repeats are encoded precisely by single exons and two of these (EIIIA and EIIIB) are alternatively spliced in a cell type-specific fashion. A third site of alternative splicing (EIIIB) reported here is similar in expression to the previously described EIIIA segment. Both are excluded from mRNA in liver cells and are, therefore, absent from plasma fibronectin. These two alternative splices, plus a third one (V) reported previously, can occur in all possible combinations giving 12 fibronectin mRNAs from a single gene. These splicing variations account for most but not all of the known fibronectin subunit variants. We report investigations designed to detect other regions of alternative splicing. We also show that the pattern of alternative splicing is somewhat altered on oncogenic transformation.

Structure of integrin, a glycoprotein involved in the transmembrane linkage between fibronectin and actin

We describe the isolation, characterization, and sequence of cDNA clones encoding one subunit of the complex of membrane glycoproteins that forms part of the transmembrane connection between the extracellular matrix and the cytoskeleton. The cDNA sequence encodes a polypeptide of 89 kd that has features strongly suggesting the presence of a large N-terminal extracellular domain, a single transmembrane segment, and a small C-terminal cytoplasmic domain. The extracellular domain contains a threefold repeat of a novel 40 residue cysteine-rich segment, and the cytoplasmic domain contains a tyrosine residue that is a potential site for phosphorylation by tyrosine kinases. We propose the name integrin for this protein complex to denote its role as an integral membrane complex involved in the transmembrane association between the extracellular matrix and the cytoskeleton.