Diagnostic Accuracy of Clinical Pathways for Suspected Acute Myocardial Infarction in the Out-of-Hospital Environment.

STUDY OBJECTIVE: Chest pain is one of the most common reasons for emergency ambulance calls. Patients are routinely transported to the hospital to prevent acute myocardial infarction (AMI). We evaluated the diagnostic accuracy of clinical pathways in the out-of-hospital environment. The Troponin-only Manchester Acute Coronary Syndromes decision aid and History, ECG, Age, Risk Factors, Troponin score require cardiac troponin (cTn) measurement, whereas the History and ECG-only Manchester Acute Coronary Syndromes decision aid and History, ECG, Age, Risk Factors score do not. METHODS: We conducted a prospective diagnostic accuracy study at 4 ambulance services and 12 emergency departments between February 2019 and March 2020. We included patients who received an emergency ambulance response in whom paramedics suspected AMI. Paramedics recorded the data required to calculate each decision aid and took venous blood samples in the out-of-hospital environment. Samples were tested using a point-of-care cTn assay (Roche cobas h232) within 4 hours. The target condition was a diagnosis of type 1 AMI, adjudicated by 2 investigators. RESULTS: Of 817 included participants, 104 (12.8%) had AMI. Setting the cutoff at the lowest risk group, Troponin-only Manchester Acute Coronary Syndromes had 98.3% sensitivity (95% confidence interval 91.1% to 100%) and 25.5% specificity (21.4% to 29.8%) for type 1 AMI. History, ECG, Age, Risk Factors, Troponin had 86.4% sensitivity (75.0% to 98.4%) and 42.2% specificity (37.5% to 47.0%); History and ECG-only Manchester Acute Coronary Syndromes had 100% sensitivity (96.4% to 100%) and 3.1% specificity (1.9% to 4.7%), whereas History, ECG, Age, Risk Factors had 95.1% sensitivity (88.9% to 98.4%) and 12.1% specificity (9.8% to 14.8%). CONCLUSION: With point-of-care cTn testing, decision aids can identify patients at a low risk of type 1 AMI in the out-of-hospital environment. When used alongside clinical judgment, and with appropriate training, such tools may usefully enhance out-of-hospital risk stratification.

External validation of the Manchester Acute Coronary Syndromes ECG risk model within a pre-hospital setting.

OBJECTIVES: The Manchester Acute Coronary Syndromes ECG (MACS-ECG) prediction model calculates a score based on objective ECG measurements to give the probability of a non-ST elevation myocardial infarction (NSTEMI). The model showed good performance in the emergency department (ED), but its accuracy in the pre-hospital setting is unknown. We aimed to externally validate MACS-ECG in the pre-hospital environment. METHODS: We undertook a secondary analysis from the Pre-hospital Evaluation of Sensitive Troponin (PRESTO) study, a multi-centre prospective study to validate decision aids in the pre-hospital setting (26 February 2019 to 23 March 2020). Patients with chest pain where the treating paramedic suspected acute coronary syndrome were included. Paramedics collected demographic and historical data and interpreted ECGs contemporaneously (as 'normal' or 'abnormal'). After completing recruitment, we analysed ECGs to calculate the MACS-ECG score, using both a pre-defined threshold and a novel threshold that optimises sensitivity to differentiate AMI from non-AMI. This was compared with subjective ECG interpretation by paramedics. The diagnosis of AMI was adjudicated by two investigators based on serial troponin testing in hospital. RESULTS: Of 691 participants, 87 had type 1 AMI and 687 had complete data for paramedic ECG interpretation. The MACS-ECG model had a C-index of 0.68 (95% CI: 0.61 to 0.75). At the pre-determined cut-off, MACS-ECG had 2.3% (95% CI: 0.3% to 8.1%) sensitivity, 99.5% (95% CI: 98.6% to 99.9%) specificity, 40.0% (95% CI: 10.2% to 79.3%) positive predictive value (PPV) and 87.6% (87.3% to 88.0%) negative predictive value (NPV). At the optimal threshold for sensitivity, MACS-ECG had 50.6% sensitivity (39.6% to 61.5%), 83.1% specificity (79.9% to 86.0%), 30.1% PPV (24.7% to 36.2%) and 92.1% NPV (90.4% to 93.5%). In comparison, paramedics had a sensitivity of 71.3% (95% CI: 60.8% to 80.5%) with 53.8% (95% CI: 53.8% to 61.8%) specificity, 19.7% (17.2% to 22.45%) PPV and 93.3% (90.8% to 95.1%) NPV. CONCLUSION: Neither MACS-ECG nor paramedic ECG interpretation had a sufficiently high PPV or NPV to 'rule in' or 'rule out' NSTEMI alone.

Diagnostic performance of GENEDIA W and ActiveXpress+ COVID-19 antigens tests among symptomatic individuals in Peru and The United Kingdom.

OBJECTIVES: In order to generate independent performance data regarding accuracy of COVID-19 antigen-based rapid diagnostic tests (Ag-RDTs), prospective diagnostic evaluation studies across multiple sites are required to evaluate their performance in different clinical settings. This report describes the clinical evaluation the GENEDIA W COVID-19 Ag Device (Green Cross Medical Science Corp., Chungbuk, Korea) and the ActiveXpress+ COVID-19 Complete Testing Kit (Edinburgh Genetics Ltd, UK), in two testing sites Peru and the United Kingdom. METHODS: Nasopharyngeal swabs collected from 456 symptomatic patients at primary points of care in Lima, Peru and 610 symptomatic participants at a COVID-19 Drive-Through testing site in Liverpool, England were analyzed by Ag-RDT and compared to RT-PCR. Analytical evaluation of both Ag-RDTs was assessed using serial dilutions of direct culture supernatant of a clinical SARS-CoV-2 isolate from the B.1.1.7 lineage. RESULTS: For GENEDIA brand, the values of overall sensitivity and specificity were 60.4% [95% CI 52.4-67.9%], and 99.2% [95% CI 97.6-99.7%] respectively; and for Active Xpress+ the overall values of sensitivity and specificity were 66.2% [95% CI 54.0-76.5%], and 99.6% [95% CI 97.9-99.9%] respectively. The analytical limit of detection was determined at 5.0 x 102 pfu/ml what equals to approximately 1.0 x 104 gcn/ml for both Ag-RDTs. The UK cohort had lower median Ct values compared to that of Peru during both evaluations. When split by Ct, both Ag-RDTs had optimum sensitivities at Ct<20 (in Peru; 95% [95% CI 76.4-99.1%] and 100.0% [95% CI 74.1-100.0%] and in the UK; 59.2% [95% CI 44.2-73.0%] and 100.0% [95% CI 15.8-100.0%], for the GENDIA and the ActiveXpress+, respectively). CONCLUSIONS: Whilst the overall clinical sensitivity of the Genedia did not meet WHO minimum performance requirements for rapid immunoassays in either cohort, the ActiveXpress+ did so for the small UK cohort. This study illustrates comparative performance of Ag-RDTs across two global settings and considers the different approaches in evaluation methods.

A prospective diagnostic evaluation of accuracy of self-taken and healthcare worker-taken swabs for rapid COVID-19 testing.

BACKGROUND: Rapid diagnostic tests (RDTs) developed for point of care detection of SARS-CoV-2 antigen are recommended by WHO to use trained health care workers to collect samples. We hypothesised that self-taken samples are non-inferior for use with RDTs to diagnose COVID-19. We designed a prospective diagnostic evaluation comparing self-taken and healthcare worker (HCW)-taken throat/nasal swabs to perform RDTs for SARS-CoV-2, and how these compare to RT-PCR. METHODS: Eligible participants 18 years or older with symptoms of COVID-19. 250 participants recruited at the NHS Test and Trace drive-through community PCR testing site (Liverpool, UK); one withdrew before analysis. Self-administered throat/nasal swab for the Covios® RDT, a trained HCW taken throat/nasal sample for PCR and HCW comparison throat/nasal swab for RDT were collected. RDT results were compared to RT-PCR, as the reference standard, to calculate sensitivity and specificity. FINDINGS: Seventy-five participants (75/249, 30.1%) were positive by RT-PCR. RDTs with self-taken swabs had a sensitivity of 90.5% (67/74, 95% CI: 83.9-97.2), compared to 78.4% (58/74, 95% CI: 69.0-87.8) for HCW-taken swabs (absolute difference 12.2%, 95% CI: 4.7-19.6, p = 0.003). Specificity for self-taken swabs was 99.4% (173/174, 95% CI: 98.3-100.0), versus 98.9% (172/174, 95% CI: 97.3-100.0) for HCW-taken swabs (absolute difference 0.6%, 95% CI: 0.5-1.7, p = 0.317). The PPV of self-taken RDTs (98.5%, 67/68, 95% CI: 95.7-100.0) and HCW-taken RDTs (96.7%, 58/60, 95% CI 92.1-100.0) were not significantly different (p = 0.262). However, the NPV of self-taken swab RDTs was significantly higher (96.1%, 173/180, 95% CI: 93.2-98.9) than HCW-taken RDTs (91.5%, 172/188, 95% CI 87.5-95.5, p = 0.003). INTERPRETATION: In conclusion, self-taken swabs for COVID-19 testing offer an accurate alternative to healthcare worker taken swabs for use with RDTs. Our results demonstrate that, with no training, self-taken throat/nasal samples can be used by lay individuals as part of rapid testing programmes for symptomatic adults. This is especially important where the lack of trained healthcare workers restricts access to testing.

PRe-hospital Evaluation of Sensitive TrOponin (PRESTO) Study: multicentre prospective diagnostic accuracy study protocol.

INTRODUCTION: Within the UK, chest pain is one of the most common reasons for emergency (999) ambulance calls and the most common reason for emergency hospital admission. Diagnosing acute coronary syndromes (ACS) in a patient with chest pain in the prehospital setting by a paramedic is challenging. The Troponin-only Manchester Acute Coronary Syndromes (T-MACS) decision rule is a validated tool used in the emergency department (ED) to stratify patients with suspected ACS following a single blood test.We are seeking to evaluate the diagnostic accuracy of the T-MACS decision aid algorithm to 'rule out' ACS when used in the prehospital environment with point-of-care troponin assays. If successful, this could allow paramedics to immediately rule out ACS for patients in the 'very low risk' group and avoid the need for transport to the ED, while also risk stratifying other patients using a single blood sample taken in the prehospital setting. METHODS AND ANALYSIS: We will recruit patients who call emergency (999) ambulance services where the responding paramedic suspects cardiac chest pain. The data required to apply T-MACS will be prospectively recorded by paramedics who are responding to each patient. Paramedics will be required to draw a venous blood sample at the time of arrival to the patient. Blood samples will later be tested in batches for cardiac troponin, using commercially available troponin assays. The primary outcome will be a diagnosis of acute myocardial infarction, established at the time of initial hospital admission. The secondary outcomes will include any major adverse cardiac events within 30 days of enrolment. ETHICS AND DISSEMINATION: The study obtained approval from the National Research Ethics Service (reference: 18/ES/0101) and the Health Research Authority. We will publish our findings in a high impact general medical journal. TRIAL REGISTRATION NUMBER: Registration number: ClinicalTrials.gov, study ID: NCT03561051.

Gestational Vitamin D Supplementation Leads to Reduced Perinatal RXRA DNA Methylation: Results From the MAVIDOS Trial.

We have previously demonstrated inverse associations between maternal 25(OH)-vitamin D status and perinatal DNA methylation at the retinoid-X-receptor-alpha (RXRA) locus and between RXRA methylation and offspring bone mass. In this study, we used an existing randomized trial to test the hypothesis that maternal gestational vitamin D supplementation would lead to reduced perinatal RXRA locus DNA methylation. The Maternal Vitamin D Osteoporosis Study (MAVIDOS) was a multicenter, double-blind, randomized, placebo-controlled trial of 1000 IU/day cholecalciferol or matched placebo from 14 weeks' gestation until delivery. Umbilical cord (fetal) tissue was collected at birth and frozen at -80°C (n = 453). Pyrosequencing was used to undertake DNA methylation analysis at 10 CpG sites within the RXRA locus (identified previously). T tests were used to assess differences between treatment groups in methylation at the three most representative CpG sites. Overall, methylation levels were significantly lower in the umbilical cord from offspring of cholecalciferol-supplemented mothers, reaching statistical significance at four CpG sites, represented by CpG5: mean difference in % methylation between the supplemented and placebo groups was -1.98% (95% CI, -3.65 to -0.32, p = 0.02). ENCODE (Encyclopedia of DNA Elements) evidence supports the functionality of this locus with strong DNase hypersensitivity and enhancer chromatin within biologically relevant cell types including osteoblasts. Enrichment of the enhancer-related H3K4me1 histone mark is also seen in this region, as are binding sites for a range of transcription factors with roles in cell proliferation, response to stress, and growth factors. Our findings are consistent with previous observational results and provide new evidence that maternal gestational supplementation with cholecalciferol leads to altered perinatal epigenetic marking, informing mechanistic understanding of early life mechanisms related to maternal vitamin D status, epigenetic marks, and bone development. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

ANRIL Promoter DNA Methylation: A Perinatal Marker for Later Adiposity.

Experimental studies show a substantial contribution of early life environment to obesity risk through epigenetic processes. We examined inter-individual DNA methylation differences in human birth tissues associated with child's adiposity. We identified a novel association between the level of CpG methylation at birth within the promoter of the long non-coding RNA ANRIL (encoded at CDKN2A) and childhood adiposity at age 6-years. An association between ANRIL methylation and adiposity was also observed in three additional populations; in birth tissues from ethnically diverse neonates, in peripheral blood from adolescents, and in adipose tissue from adults. Additionally, CpG methylation was associated with ANRIL expression in vivo, and CpG mutagenesis in vitro inhibited ANRIL promoter activity. Furthermore, CpG methylation enhanced binding to an Estrogen Response Element within the ANRIL promoter. Our findings demonstrate that perinatal methylation at loci relevant to gene function may be a robust marker of later adiposity, providing substantial support for epigenetic processes in mediating long-term consequences of early life environment on human health.

Perinatal DNA Methylation at CDKN2A Is Associated With Offspring Bone Mass: Findings From the Southampton Women's Survey.

Poor intrauterine and childhood growth has been linked with the risk of osteoporosis in later life, a relationship that may in part be mediated through altered epigenetic regulation of genes. We previously identified a region within the promoter of the long non-coding RNA ANRIL encoded by the CDKN2A locus, at which differential DNA methylation at birth showed correlations with offspring adiposity. Given the common lineage of adipocytes and osteoblasts, we investigated the relationship between perinatal CDKN2A methylation and bone mass at ages 4 and 6 years. Using sodium bisulfite pyrosequencing, we measured the methylation status of the 9 CpGs within this region in umbilical cord samples from discovery (n = 332) and replication (n = 337) cohorts of children from the Southampton Women's Survey, whose bone mass was assessed by dual-energy X-ray absorptiomietry (DXA; Hologic Discovery). Inverse associations were found between perinatal CDKN2A methylation and whole-body minus head bone area (BA), bone mineral content (BMC), and areal bone mineral density (BMD). This was confirmed in replication and combined data sets (all p < 0.01), with each 10% increase in methylation being associated with a decrease in BMC of 4 to 9 g at age 4 years (p ≤ 0.001). Relationships were similar with 6-year bone mass. Functional investigation of the differentially methylated region in the SaOS-2 osteosarcoma cell line showed that transcription factors bound to the identified CpGs in a methylation-specific manner and that CpG mutagenesis modulated ANRIL expression. In conclusion, perinatal methylation at CDKN2A is associated with childhood bone development and has significance for cell function. © 2017 American Society for Bone and Mineral Research.