Implementation of high-sensitivity cardiac troponin and risk of myocardial infarction or death at 5 years: a stepped-wedge cluster-randomised controlled trial

Background

Implementation of a high-sensitivity cardiac troponin I assay with the sex-specific 99th centile as the diagnostic threshold identifies more patients with myocardial injury and infarction, but whether this impacts on long-term clinical outcomes is unknown.

Purpose

In a prespecified analysis of a stepped-wedge cluster-randomised controlled trial performed across ten hospitals in Scotland, we evaluated the impact of implementing a high-sensitivity cardiac troponin I assay on outcomes at 5 years in consecutive patients with suspected acute coronary syndrome.

Methods

Throughout the trial, all 48,282 patients had cardiac troponin I concentrations measured using both a contemporary (standard care) and high-sensitivity (implementation) assay. During standard care, results from the high-sensitivity assay were concealed and the contemporary assay was used to guide care. Hospitals were randomly allocated to early (n=5) or late (n=5) implementation of the high-sensitivity assay using the sex-specific 99th centile to guide care and results from the contemporary assay were concealed. Patients reclassified by the high-sensitivity assay were defined as those with cardiac troponin concentrations above the sex-specific 99th centile but below the contemporary assay diagnostic threshold. Subsequent myocardial infarction or all-cause death at 5 years was compared before and after implementation using an adjusted Cox proportional hazards model in those reclassified by the high-sensitivity assay and stratified by index diagnosis.

Results

Overall, 10,360 patients had cardiac troponin concentrations greater than the sex-specific 99th centile of whom 1,771 (17%) were reclassified by the high-sensitivity assay. Compared to those identified as having elevated cardiac troponin by the contemporary assay, patients reclassified by the high-sensitivity assay were more likely to have non-ischemic myocardial injury (54% versus 28%) and less likely to have type 1 myocardial infarction (33% versus 59%; P<0.001 for both). In those reclassified, the 5-year incidence of subsequent myocardial infarction or all-cause death was 63% (456/720) before and 54% (567/1051) after implementation of the high-sensitivity assay (adjusted hazard ratio [aHR] 0.75 [95% CI 0.57–0.98]) (Figure 1). Following implementation, subsequent myocardial infarction or all-cause death at 5 years was reduced in patients with non-ischemic myocardial injury (aHR 0.66 [0.51–0.86]) but not type 1 or type 2 myocardial infarction (aHR 0.90 [0.78–1.03] and 0.81 [0.55–1.20], respectively).

Conclusions

In patients with suspected acute coronary syndrome, implementation of a high-sensitivity cardiac troponin assay was associated with a lower risk of subsequent myocardial infarction or death at 5 years. Improvements in outcome were greater in those with a diagnosis of non-ischemic myocardial injury rather than infarction.

Funding Acknowledgement

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

Impact of patient selection on performance of an early rule-out pathway for myocardial infarction: from research to the real world

Background

Early rule-out pathways for myocardial infarction using high-sensitivity cardiac troponin are widely recommended in the assessment of patients with suspected acute coronary syndrome. Although developed in selected patients participating in research studies, these pathways are applied more widely in clinical practice where the diagnostic performance and effectiveness of these pathways may differ.

Purpose

To evaluate the performance of an early rule-out pathway for myocardial infarction using high-sensitivity cardiac troponin in selected and consecutive unselected patients with suspected acute coronary syndrome.

Methods

Presentation and serial high-sensitivity cardiac troponin I concentrations were measured in two cohorts of patients with suspected acute coronary syndrome presenting to the Emergency Departments across three acute care hospitals in Scotland. In the unselected cohort, electronic health record data were collected on consecutive patients in whom the usual care clinician measured cardiac troponin for suspected acute coronary syndrome. In the selected cohort, patients with suspected acute coronary syndrome were approached between 8am and 8pm by research staff and written informed consent obtained. In both cohorts, the performance of the High-STEACS early rule-out pathway was evaluated for an adjudicated diagnosis of myocardial infarction (type 1, type 4b or type 4c) during the index hospital admission.

Results

The unselected and selected patient cohorts comprised of 1,242 (median age 60 [interquartile range 47–75] years, 46% women) and 1,695 (median age 61 [52–73] years, 40% women) patients respectively. Myocardial infarction was diagnosed in 6% (74/1,242) and 14% (232/1,695) of patients in the unselected and selected patient cohorts respectively. More patients had myocardial infarction ruled-out in the unselected (74% [828/1,112] versus 66% [1,102/1,678]; P<0.001), with similar negative predictive value (99.9% [95% CI 99.7%-100%] versus 99.7% [95% CI 99.4%-99.0%) and sensitivity (99.3% [95% CI 97.4%-100%] versus 98.9% [95% CI 97.6%-99.9%]; Figure 1). In the selected cohort, more patients had intermediate troponin concentrations requiring serial testing (36% versus 29%) or had myocardial infarction diagnosed (34% versus 26%; P<0.001 for both). In contrast, the positive predictive value for myocardial infarction was lower in unselected patients (26.1% [95% CI 21.2%-31.4%] versus 39.9% [95% CI 35.9%-44.0%]).

Conclusion

The prevalence of myocardial infarction is lower in patients with suspected acute coronary syndrome evaluated in routine practice compared to those selected to participate in a research study. Whilst more patients have myocardial infarction accurately ruled out, the positive-predictive value in those ruled in is lower resulting in more hospital admissions with elevated cardiac troponin due to other conditions.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): British Heart FoundationMedical Research Council

P10.12.A CDK12/CDK13 inhibition disrupts a transcriptional program critical for glioblastoma survival

Background

Glioblastoma multiforme (GBM) is the most prevalent and aggressive malignant tumor of the central nervous system. With a median survival of only one year, GBM patients have a particularly poor prognosis, highlighting a clear need for novel therapeutic strategies to target this disease. Transcriptional cyclin-dependent kinases (CDK), which phosphorylate key residues of RNA polymerase II (RNAPII) C-terminal domain (CTD), play a major role in sustaining aberrant transcriptional programs that are key to development and maintenance of cancer cells.

Material and Methods

We used pharmacological inhibition and genetic ablation to study effects of CDK12/CDK13 depletion on the proliferatory and migratory capacity of GBM cells and mouse xenografts. SLAM-seq, CUT&RUN and cell cycle assays were used to study the mechanistic effects of CDK12/CDK13 depletion in GBM cells.

Results

CDK12/CDK13 depletion markedly reduced the proliferatory and migratory capacity of GBM cells, as well as in vivo growth. CDK12/CDK13 inhibition potentiated existing chemotherapeutic treatments. Mechanistically, inhibition of CDK12/CDK13 leads to a genome-wide abrogation of RNAPII CTD phosphorylation, which in turn disrupts transcription and cell cycle progression in GBM cells.

Conclusion

These results provide proof-of-concept for the potential of CDK12 and CDK13 as therapeutic targets for GBM.

P12.08.A Uncovering the glioblastoma tumor-microenvironment by high-end multiplexing with imaging mass cytometry

Background

Glioblastoma is one of the most aggressive cancers, and hypoxia plays an essential role in its tumor- microenvironment. Tumor-associated microglia and macrophages (TAMs) have been reported to constitute up to 30 % of the cells, a fraction that is even higher in hypoxic areas. Single-cell mRNA sequencing of glioblastoma tumors has revealed vast heterogeneity, but the spatial aspects are not entirely defined yet. The aim of this study was to uncover differences between the hypoxic and normoxic tumor-microenvironment of human glioblastoma by high-end multiplexing with imaging mass cytometry.

Material and Methods

A tissue microarray (TMA) with normoxic and hypoxic areas from 4 IDH-wildtype glioblastomas was prepared based on the hypoxia marker hypoxia-inducing factor 1 alpha (HIF1 alpha). The TMA was stained with 18 metal-tagged antibodies covering TAMs, lymphocytes, immune checkpoints, vessels, tumor cells and proliferation. The Hyperion-CYTOF technology was used to ablate the samples and the images were analyzed by MCD viewer, Visiopharm software, and customized R scripts.

Results

Single-cell analysis of 160 fields covering around 45,000 cells in the glioblastoma microenvironment revealed multiple cellular phenotypes. It was revealed that proliferating TAMs (IBA1+, Ki67+) were more frequent in hypoxia, whereas proliferating vessels (CD34+, Ki67+) were more frequent in normoxia. Additionally, proliferating stem-like tumor cells (OLIG-2+, Ki67+) were more frequent in normoxia regions.

Conclusion

Our study revealed multiple cellular phenotypes in the glioblastoma microenvironment. The TAMs, endothelial and tumor cell phenotypes revealed may play a critical role in glioblastoma biology however this needs to be elucidated in future studies.

Scalable radiotherapy data curation infrastructure for deep-learning based autosegmentation of organs-at-risk: A case study in head and neck cancer

In this era of patient-centered, outcomes-driven and adaptive radiotherapy, deep learning is now being successfully applied to tackle imaging-related workflow bottlenecks such as autosegmentation and dose planning. These applications typically require supervised learning approaches enabled by relatively large, curated radiotherapy datasets which are highly reflective of the contemporary standard of care. However, little has been previously published describing technical infrastructure, recommendations, methods or standards for radiotherapy dataset curation in a holistic fashion. Our radiation oncology department has recently embarked on a large-scale project in partnership with an external partner to develop deep-learning-based tools to assist with our radiotherapy workflow, beginning with autosegmentation of organs-at-risk. This project will require thousands of carefully curated radiotherapy datasets comprising all body sites we routinely treat with radiotherapy. Given such a large project scope, we have approached the need for dataset curation rigorously, with an aim towards building infrastructure that is compatible with efficiency, automation and scalability. Focusing on our first use-case pertaining to head and neck cancer, we describe our developed infrastructure and novel methods applied to radiotherapy dataset curation, inclusive of personnel and workflow organization, dataset selection, expert organ-at-risk segmentation, quality assurance, patient de-identification, data archival and transfer. Over the course of approximately 13 months, our expert multidisciplinary team generated 490 curated head and neck radiotherapy datasets. This task required approximately 6000 human-expert hours in total (not including planning and infrastructure development time). This infrastructure continues to evolve and will support ongoing and future project efforts.

Characterization of crtRB1- and vte4-based biofortified sweet corn inbreds for seed vigour and physico-biochemical traits

Sweet corn possessing recessive shrunken2 (sh2) gene is popular worldwide. Traditional sweet corn is poor in vitamin A and vitamin E. Plant breeders during the selection of sweet corn genotypes mainly emphasize on plant architecture and yield. Seed germination and seedling vigour play important role for early establishment in field, thereby increasing yield and income. Here, we analysed a set of 15 sh2-based biofortified sweet corn inbreds with crtRB1 (β-carotene hydroxylase1) and vte4 (γ-tocopherol methyltransferase) genes and three traditional sh2-based sweet corn inbreds for nutritional quality, seed vigour and various physico-biochemical traits. The newly developed inbreds possessed significantly higher provitamin A (proA: 15.60 µg/g) and vitamin E [α-tocopherol (α-T): 20.42 µg/g] than the traditional sweet corn inbreds (proA: 2.51 µg/g, α-T: 11.16 µg/g). The biofortified sweet corn inbreds showed wide variation for germination (80.67-87.33%), vigour index-I (2097.17-2925.28 cm), vigour index-II (134.27-216.19 mg) and electrical conductivity (10.19-13.21 μS cm^-1 g^-1). Wide variation was also observed for dehydrogenase (1.29-1.59 OD g^-1 ml^-1), super oxide dismutase (4.01-9.82 g^-1), peroxidase (11.66-16.47 μM min^-1 g^-1), esterase (22.98-34.76 nM min^-1 g^-1) and α-amylase (5.91-8.15 OD g^-1 ml^-1). Enrichment of proA and vitamin E in sweet corn did not affect seed vigour and physico-biochemical traits. Correlation analysis revealed that electrical conductivity and α-amylase activity was the reliable indicator for assessing seed germination and vigour. The study identified superior biofortified sweet corn genotypes that would contribute to better vigour and establishment in field. This is the first report of analysis of biofortified sweet corn genotypes for seed vigour and physico-biochemical traits.

709 IMPACT ON HEALTHCARE UTILISATION OF A GENERAL PRACTITIONER-LED MODEL OF CARE FOR PATIENTS WITH FRAILTY

Introduction

Primary care has a significant role to play in the identification and management of frailty. MidMed is a new dedicated GP-led service developed by a large practice in Midlothian for patients living at home with moderate or severe frailty. MidMed comprises a full-time GP performing a comprehensive geriatric assessment (CGA) adapted for primary care. Patients receive direct access to all appointments with the named GP. The aim of this study was to assess the impact of MidMed on healthcare utilisation in this patient group.

Methods

Patients with moderate or severe frailty at the MidMed practice were identified by the electronic Frailty Index (>0.24). After 16 months, patients who had been accepted into MidMed (MidMed group) were compared with those yet to be enrolled and who continued to receive usual care (non-MidMed group). Routinely collected data were used to identify outcomes including unscheduled hospital admissions, primary care consultations, continuity of care, outpatient attendances and mortality. Adjusted rate ratios were estimated using regression models.

Results

510 patients with moderate or severe frailty were identified (290 in MidMed, 220 in non-MidMed). Patients in each group were just as likely to have at least one hospital admission per year but those in MidMed had a reduced risk of further hospital admission compared to the non-MidMed group (adjusted RR 0.46 [95%CI 0.30–0.71]). MidMed was also associated with statistically significant higher usage of primary care (adjusted RR 1.52, [95%CI, 1.30–1.75]) and better continuity of care. There was no difference in mortality or the number of outpatient appointments when adjusted for co-variates.

Conclusion

A GP-led service for frailty is associated with lower risk of hospital readmission and improved continuity of care. Further studies are now required to better understand why use of such primary care services increase and whether this changes over time.

795 A POSITIVE 4AT DELIRIUM ASSESSMENT TOOL SCORE ON HOSPITAL ADMISSION IS LINKED TO MORTALITY, LENGTH OF STAY AND ‘HOME TIME’: A STUDY OF 82,770 HOSPITAL ADMISSIONS IN EDINBURGH AND SALFORD

Introduction

Delirium is linked with poor outcomes but studies using large-scale routine data are scarce. The 4AT (www.the4AT.com) is a brief (~2 minutes), well-validated tool for detection of delirium and cognitive impairment. We performed a two-centre study (Edinburgh and Salford) of Electronic Health Record (EHR) 4AT scores and outcomes in 82,770 non-elective hospital admissions in patients aged ≥65. We determined relationships between 4AT scores 0 (no impairment), 1–3 (cognitive impairment but no delirium) and ≥ 4 (delirium), in relation to 30-day inpatient mortality, length of stay, and time at home (‘home time’) in the year following index admission.

Methods

We analysed EHR 4AT scores recorded within 24 hours of admission, and outcomes data were also derived from the EHR. The study period was between April 2016 (Edinburgh)/September 2017 (Salford) and April 2020 (both centres).

Results

4AT scores suggestive of delirium (≥4) were present in 25% in Salford, and 18% in Edinburgh. After adjustment for age and sex, 30-day inpatient mortality with 4AT ≥4 was 5.5-fold greater than the 4AT 0 group in Edinburgh (aOR 5.53, 95% confidence interval [CI] 4.99–6.13) and 3.4-fold greater in Salford (aOR 3.39, 95% CI 2.98–3.87). Length of stay was more than double in patients with any abnormal 4AT score compared to a 4AT score of 0. The median ‘home time’ at 1 year was reduced by 112 days (Edinburgh) and 61 days (Salford) in the 4AT ≥4 compared to 4AT 0 days.

Conclusions

This large study using routine clinical data confirms the relationships between delirium and poor outcomes previously reported in smaller research studies. Further, the results demonstrate the feasibility and value of using a brief clinical tool to identify delirium as a strong marker of adverse outcomes, and will be helpful in guiding policy development around patient safety including better treatment of delirium.

Sugar metabolism during pre- and post-fertilization events in plants under high temperature stress

High temperature challenges global crop production by limiting the growth and development of the reproductive structures and seed. It impairs the developmental stages of male and female gametogenesis, pollination, fertilization, endosperm formation and embryo development. Among these, the male reproductive processes are highly prone to abnormalities under high temperature at various stages of development. The disruption of source-sink balance is the main constraint for satisfactory growth of the reproductive structures which is disturbed at the level of sucrose import and utilization within the tissue. Seed development after fertilization is affected by modulation in the activity of enzymes involved in starch metabolism. In addition, the alteration in the seed-filling rate and its duration affects the seed weight and quality. The present review critically discusses the role of sugar metabolism in influencing the various stages of gamete and seed development under high temperature stress. It also highlights the interaction of the sugars with hormones that mediate the transport of sugars to sink tissues. The role of transcription factors for the regulation of sugar availability under high temperature has also been discussed. Further, the omics-based systematic investigation has been suggested to understand the synergistic or antagonistic interactions between sugars, hormones and reactive oxygen species at various points of sucrose flow from source to sink under high temperature stress.

Metal tolerance in plants: Molecular and physicochemical interface determines the "not so heavy effect" of heavy metals

An increase in technological interventions and ruthless urbanization in the name of development has deteriorated our environment over time and caused the buildup of heavy metals (HMs) in the soil and water resources. These heavy metals are gaining increased access into our food chain through the plant and/or animal-based products, to adversely impact human health. The issue of how to restrict the entry of HMs or modulate their response in event of their ingress into the plant system is worrisome. The current knowledge on the interactive-regulatory role and contribution of different physical, biophysical, biochemical, physiological, and molecular factors that determine the heavy metal availability-uptake-partitioning dynamics in the soil-plant-environment needs to be updated. The present review critically analyses the interactive overlaps between different adaptation and tolerance strategies that may be causally related to their cellular localization, conjugation and homeostasis, a relative affinity for the transporters, rhizosphere modifications, activation of efflux pumps and vacuolar sequestration that singly or collectively determine a plant's response to HM stress. Recently postulated role of gaseous pollutants such as SO₂ and other secondary metabolites in heavy metal tolerance, which may be regulated at the whole plant and/or tissue/cell is discussed to delineate and work towards a "not so heavy" response of plants to heavy metals present in the contaminated soils.

Antimicrobial effectiveness of Nano Silver Fluoride Varnish in reducing Streptococcus mutans in saliva and plaque biofilm when compared with Chlorhexidine and Sodium Fluoride Varnishes

Background

This in vivo study was done to investigate the antimicrobial effectiveness of Nano Silver fluoride, Sodium fluoride and Chlorhexidine when used as a varnish on Streptococcus mutans (S.mutans) in saliva and plaque biofilm.

Material and Methods

120 caries free subjects, aged 8-10 years were randomly assigned to four different groups (n=30) - group I: Control, group II: Chlorhexidine varnish (CHX), group III: Sodium fluoride varnish (NaF), group IV: Nano Silver fluoride varnish (NSF). Varnish application was done once at baseline. Saliva and plaque samples were collected at baseline (T0), at the end of 1 month (T1) and 3 months (T3) to evaluate S.mutans levels by culture method, optical density and PCR. OHI-S Index was also recorded for clinical evaluation.

Results

NSF, CHX and NaF were effective against S.mutans activity. The intragroup comparision of CFU/ml and OD/ml count showed a highly significant reduction from baseline to 3 months for all the 3 varnish groups (p=0.001). PCR result revealed that maximum reduction was seen in NSF and CHX followed by NaF group.

Conclusions

NSF reduces S.mutans level in both saliva and plaque biofilm and it is more advantageous than CHX and NaF as it has dual properties of acting as an antibacterial as well as a remineralizing agent.

Key words:Chlorhexidine, Nano Silver fluoride, Sodium fluoride, S. mutans, varnish.

Development of DNA Aptamers to Visualize Release of Mycobacterial Membrane-Derived Extracellular Vesicles in Infected Macrophages

Extracellular vesicles (EVs) have emerged into a novel vaccine platform, a biomarker and a nano-carrier for approved drugs. Their accurate detection and visualization are central to their utility in varied biomedical fields. Owing to the limitations of fluorescent dyes and antibodies, here, we describe DNA aptamer as a promising tool for visualizing mycobacterial EVs in vitro. Employing SELEX from a large DNA aptamer library, we identified a best-performing aptamer that is highly specific and binds at nanomolar affinity to EVs derived from three diverse mycobacterial strains (pathogenic, attenuated and avirulent). Confocal microscopy revealed that this aptamer was not only bound to in vitro-enriched mycobacterial EVs but also detected EVs that were internalized by THP-1 macrophages and released by infecting mycobacteria. To the best of our knowledge, this is the first study that detects EVs released by mycobacteria during infection in host macrophages. Within 4 h, most released mycobacterial EVs spread to other parts of the host cell. We predict that this tool will soon hold huge potential in not only delineating mycobacterial EVs-driven pathogenic functions but also in harboring immense propensity to act as a non-invasive diagnostic tool against tuberculosis in general, and extra-pulmonary tuberculosis in particular.

A novel G-quadruplex aptamer-based spike trimeric antigen test for the detection of SARS-CoV-2

The recent SARS-CoV-2 outbreak has been declared a global health emergency. It will take years to vaccinate the whole population to protect them from this deadly virus, hence the management of SARS-CoV-2 largely depends on the widespread availability of an accurate diagnostic test. Toward addressing the unmet need of a reliable diagnostic test in the current work by utilizing the power of Systematic Evolution of Ligands by EXponential enrichment, a 44-mer G-quadruplex-forming DNA aptamer against spike trimer antigen of SARS-CoV-2 was identified. The lead aptamer candidate (S14) was characterized thoroughly for its binding, selectivity, affinity, structure, and batch-to-batch variability by utilizing various biochemical, biophysical, and in silico techniques. S14 has demonstrated a low nanomolar KD, confirming its tight binding to a spike antigen of SARS-CoV-2. S14 can detect as low as 2 nM of antigen. The clinical evaluation of S14 aptamer on nasopharyngeal swab specimens (n = 232) has displayed a highly discriminatory response between SARS-CoV-2 infected individuals from the non-infected one with a sensitivity and specificity of ∼91% and 98%, respectively. Importantly, S14 aptamer-based test has evinced a comparable performance with that of RT-PCR-based assay. Altogether, this study established the utility of aptamer technology for the detection of SARS-CoV-2.

Raffinose accumulation and preferential allocation of carbon (14 C) to developing leaves impart salinity tolerance in sugar beet

Sugar beet is a salt-tolerant crop that can be explored for crop production in degraded saline soils. Seeds of multigerm genotypes LKC-2006 (susceptible) and LKC-HB (tolerant) were grown in 150 mM NaCl, from germination to 60 days after sowing, to decipher the mechanism of salinity tolerance at the vegetative stage. The biomass of the root and leaf were maintained in the tolerant genotype, LKC-HB, under saline conditions. Na⁺ /K⁺ ratios were similar in roots and leaves of LKC-HB, with lower values under salinity compared to LKC 2006. Infrared temperatures were 0.96°C lower in LKC-HB than in LKC-2006, which helped regulate the leaf water status under stressed conditions. Pulse-chase experiment showed that ¹⁴ C photosynthate was preferentially allocated towards the development of new leaves in the tolerant genotype. The sugar profile of leaves and roots showed accumulation of raffinose in leaves of LKC-HB, indicating a plausible role in imparting salinity tolerance by serving as an osmolyte or scavenger. The molecular analysis of the genes responsible for raffinose synthesis revealed an 18-fold increase in the expression of BvRS2 in the tolerant genotype, suggesting its involvement in raffinose synthesis. Our study accentuated that raffinose accumulation in leaves is vital for inducing salinity tolerance and maintenance of shoot dry weight in sugar beet.

The impact of age on the diagnosis of type 1 myocardial infarction using high-sensitivity cardiac troponin

Background

Cardiac troponin concentrations are influenced by age and comorbidities with values above the 99th centile diagnostic threshold more common in older patients without myocardial infarction. Despite this, rule-in thresholds for myocardial infarction are applied universally regardless of age or comorbidities.

Purpose

We sought to evaluate how age and cardiovascular comorbidities influence the diagnostic performance of high-sensitivity cardiac troponin I for myocardial infarction.

Methods

In a secondary analysis of a multi-centre randomised controlled trial, we identified 45,991 consecutive patients with suspected acute coronary syndrome without ST-segment elevation myocardial infarction. The diagnostic performance of high-sensitivity cardiac troponin I measured at presentation for type 1 myocardial infarction was evaluated for the sex-specific 99th centile and thresholds three and five times this value in patients stratified by age (under 50 years, between 50 and 75 years, and over 75 years). The effect of comorbidities on diagnostic accuracy was evaluated using regression modelling.

Results

Of the 45,991 patients, 8,187 (18%) had myocardial injury of which 7,677 (94%) had a presentation troponin above the sex-specific 99th centile. Mean age of those with myocardial injury was 74 years (range 18–108). The positive predictive value (PPV) of the 99th centile was 54.6% (95% confidence interval [CI] 50.6–58.8%), 58.8% (56.9–60.6%) and 36.6% (35.1–38.2%) in patients under 50 years, between 50 and 75 years, and over 75 years, respectively. Rule-in thresholds three and five-times the 99th centile gave a higher PPV in all age groups with a PPV of 45.5% (43.1–47.8%) and 50.4% (47.6–53.2%), respectively in those aged over 75 years (Table 1). Regardless of threshold, specificity and PPV was lowest in patients over 75 years and decreased with advancing age (Figure 1). Across all age groups, the presence of heart failure resulted in the greatest decrease in PPV (36.9% [34.6–39.2%] versus 50.6% [49.3–51.8%]). Adjusting for cardiovascular comorbidities resulted in modest change in the discrimination of cardiac troponin for myocardial infarction (area under curve 0.89 vs 0.90) and did not prevent a decline in diagnostic accuracy in older patients.

Conclusion

The specificity and PPV of high-sensitivity cardiac troponin I for myocardial infarction decreases with advancing age. Cardiovascular comorbidities impact the PPV of troponin, but do not explain the decline in diagnostic accuracy with age. Clinicians should be aware of these important differences in performance by age of the diagnostic and rule-in thresholds for myocardial infarction when interpreting troponin results in older patients.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): University of Edinburgh Figure 1

Trajectories of high-sensitivity cardiac troponin I in the two decades before cardiovascular death in Whitehall II

Background

High-sensitivity cardiac troponin may be a promising biomarker that could be used for personalised cardiovascular risk prediction and monitoring in the general population. Temporal changes in high-sensitivity cardiac troponin before cardiovascular death are largely unexplored.

Purpose

Using the longitudinal Whitehall II cohort, we evaluated whether three serial high-sensitivity cardiac troponin I measurements over 15 years improved prediction of cardiovascular death when compared to a single time point at baseline.

Methods

Whitehall II is an ongoing longitudinal observation cohort study of 10,308 civil servants, and we included participants who had at least one cardiac troponin measurement and outcome data available. We constructed time trajectories to evaluate the temporal pattern of cardiac troponin I in those who died from cardiovascular disease as compared to those who did not. Cox regression and joint models were used to investigate the association of cardiac troponin I in relation to cardiovascular death using single time point (at baseline) and repeated measurements (at baseline, 10 and 15 years), respectively. The discriminative ability was assessed by the concordance index.

Results

In total, we included 7,293 individuals (mean age of 58 years [SD 7] at baseline, 29.4% women). Of these, 5,818 (79.8%) and 4,045 (55.5%) individuals had a second and third cardiac troponin I concentration measured, respectively. Cardiovascular death occurred in 281 (3.9%) individuals during a median follow-up of 21.4 [IQR, 15.8 to 21.8] years. In the 21-year trajectories of cardiac troponin I, we observed higher baseline concentrations in those who died due to cardiovascular disease as compared to those who did not (median 5 [IQR, 2 to 9] ng/L versus 3 [IQR, 2 to 5] ng/L respectively, Figure). Cardiac troponin I was an independent predictor of cardiovascular death, and the hazard ratio (HR) derived from the joint model that included serial cardiac troponin measurements was higher than the HR derived from the single time point model (single time point model: adjusted HR 1.53, 95% Confidence Interval [CI] 1.37 to 1.70 per naturally log transformed unit of cardiac troponin I, versus repeated measurements model: adjusted HR 1.79, 95% CI 1.58 to 2.02). The discriminative ability of the cardiac troponin model improved when using repeated measurements (concordance index of unadjusted cardiac troponin models, single time point: 0.668 versus repeated measurements: 0.724).

Conclusions

Our study shows that cardiac troponin I trajectories were persistently higher among individuals who died from cardiovascular disease. Cardiac troponin I is a strong independent predictor of cardiovascular death, and incorporating repeated measurements of cardiac troponin improves cardiovascular risk prediction in the general population.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Cardiac troponin I measurements and analysis were supported by were supported by Siemens Healthineers. The study was supported by Health Data Research UK which receives its funding from HDR UK Ltd (HDR-5012) funded by the UK Medical Research Council, Engineering and Physical Sciences Research Council, Economic and Social Research Council, Department of Health and Social Care (England), Chief Scientist Office of the Scottish Government Health and Social Care Directorates, Health and Social Care Research and Development Division (Welsh Government), Public Health Agency (Northern Ireland), British Heart Foundation and the Wellcome Trust. NLM is supported by the British Heart Foundation through a Senior Clinical Research Fellowship (FS/16/14/32023), Programme Grant (RG/20/10/34966) and a Research Excellence Award (RE/18/5/34216). The funders had no role in the study and the decision to submit this work to be considered for publication.

Mechanisms of myocardial injury and clinical outcomes in patients hospitalised with suspected COVID-19

Background

Myocardial injury is associated with adverse outcomes in patients with COVID-19. However, the prognostic role of myocardial injury in COVID-19 compared to other acute illnesses and the underlying mechanisms of injury are poorly understood.

Methods

In a prospective, multi-centre, cohort study conducted in secondary and tertiary care hospitals in Scotland, all consecutive patients with suspected COVID-19 underwent cardiac troponin (ARCHITECTSTAT high-sensitive troponin I (hs-cTnI) assay; Abbott Laboratories) testing in plasma that was surplus to clinical requirements. The results were not reported unless required by the attending clinician. We evaluated the prevalence of myocardial injury, mechanisms and outcomes in all patients. In those with any hs-cTnI concentration above the sex-specific 99th centile the diagnosis was adjudicated according to the 4th Universal Definition of Myocardial Infarction. The primary outcome of all-cause mortality was compared in those with and without myocardial injury and COVID-19 by cox regression adjusted for age, sex, renal function and co-morbidities.

Results

A total of 2,916 (median age 69 [interquartile range, IQR 54–79] years, 53% women) consecutive patients with suspected COVID-19 were followed up for 228 [IQR 203–249] days. Myocardial injury occurred in 26% (750/2,916) with a median troponin concentration of 66 [35–178] ng/L; the prevalence was 41% (46/112) and 25% (704/2,804) in those with and without COVID-19, respectively. The most common mechanism was acute non-ischaemic myocardial injury occurring in 80% (37/46) and 71% (502/704) of patients with and without COVID-19, respectively. Type 1 myocardial infarction (2% and 4%), type 2 myocardial infarction (7% and 14%) and chronic myocardial injury (11% and 11%) were less common and only one patient had confirmed myocarditis. In patients with myocardial injury mortality was increased compared to those without (P<0.001 log rank), whether they had COVID-19 (54% [25/46] versus 26% [17/66]) or not (35% [248/704] versus 14% [294/2100]). Myocardial injury was an independent predictor of death in all patients (adjusted hazard ratio [aHR] 2.04, 95% confidence interval [CI] 1.71 to 2.43), but this excess risk was not higher in patients with COVID-19 (aHR 1.58, 95% CI 0.75 to 3.15) compared to those without the condition (aHR 2.01, 95% CI 1.81 to 2.49).

Conclusion

Myocardial injury is common in hospitalised patients with suspected COVID-19 whether or not COVID-19 was the cause of their presentation. The majority of patients had acute non-ischaemic myocardial injury rather than a defined cardiac condition. Despite this the presence of myocardial injury was an independent predictor of death in all hospitalised patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): British Heart Foundation Kaplan-Meier curve for all-cause death

Snapshots quiz

A 25-year old gentleman, treated one year previously for a signet ring mid rectal adenocarcinoma, presented with facial swelling and multiple nodular swellings on the neck and back. What is the diagnosis?

Neutrophil to lymphocyte ratio as a prognostic marker for non-metastatic renal cell carcinoma - does it add to what we already know?

AIM

To study the correlation of pre-operative neutrophil to lymphocyte ratio (NLR) with pathological stage, Fuhrman grade, sarcomatoid differentiation, tumor necrosis and lymph node positivity and its prognostic role in non-metastatic renal cell carcinoma (non-mRCC).

MATERIALS AND METHODS

This retro-prospective, observational study was done at a tertiary care center in Mumbai, India. All patients with non-mRCC from July 2015 to April 2018 were included. Patients with co-existing systemic infection, prior immunotherapy, and long-term steroids were excluded. NLR closest to surgery, but within one month prior to surgery was used. Patients were stratified as NLR ≥ 3.0 or < 3. NLR was correlated with known prognostic factors by Pearson's correlation.

RESULTS

113 patients, aged 18-81 years (83 males and 30 females) were included. 75% had clear cell RCC. 62% had stage 1 disease. 58% patients had Fuhrman Grade 2. 10 patients had lymph node metastasis, 6 had sarcomatoid differentiation, 40 had tumor necrosis. The NLR was < 3 in 72 patients. Statistically significant correlation between NLR and tumor stage (p = 0.0054) as well as NLR and tumor necrosis (p = 0.0128) was shown.

CONCLUSIONS

NLR correlates significantly with higher T stage and tumor necrosis. NLR may be integrated with well-established prognostic markers to improve the accuracy of prognostic scores.