John W Pickering

University of Otago · Department of Medicine (Christchurch)

Background: High-sensitivity assays for cardiac troponin T (hs-cTnT) are sometimes used to rapidly rule out acute myocardial infarction (AMI). Purpose: To estimate the ability of a single hs-cTnT concentration below the limit of detection (<0.005 µg/L) and a nonischemic electrocardiogram (ECG) to rule out AMI in adults presenting to the emergenc...

Background: Efforts to safely reduce length of stay for emergency department patients with symptoms suggestive of acute coronary syndrome (ACS) have had mixed success. Few system-wide efforts affecting multiple hospital emergency departments have ever been evaluated. We evaluated the effectiveness of a nationwide implementation of clinical pathway...

Importance Emergency department (ED) investigations of patients with suspected acute myocardial infarction (AMI) are time consuming, partly because of the turnaround time of laboratory tests. Current point-of-care troponin assays shorten test turnaround times but lack precision at lower concentrations. Development of point-of-care troponin assays w...

Background: Variations in cardiac troponin concentrations by age, sex and time between samples in patients with suspected myocardial infarction are not currently accounted for in diagnostic approaches. We aimed to combine these variables through machine learning to improve the assessment of risk for individual patients. Methods: A machine learni...

Background In 2012 in a hospital, New Zealand, a chest pain pathway was instituted for the use in patients presenting to the Emergency Department (ED) with undifferentiated chest pain. This reduced hospital admissions and ED length of stay (LOS) without adversely affecting outcomes. The pathway consists of risk stratification combined with ECG and...

Background After rule-out of MI in ED chest pain patients, uncertainty exists with respect to which remaining patients would benefit from objective functional/anatomical testing to detect potential underlying CAD. Using proteomics, we experimentally identified IGFBP-3 as a biomarker to assist this risk stratification and applied its measurement to...

Background Point-of-care (POC) high-sensitivity troponin (hs-cTn) assays within a clinical pathway may safely reduce length of stay (LoS) for patients presenting to the emergency department (ED) with possible acute myocardial infarction (AMI). In this early-report we present the first evaluation of a POC hs-cTn in real-life care. Methods In adult...

Objectives The Siemens Point-of-Care Testing (POC) Atellica® VTLi high-sensitivity troponin I (hsTnI) device has been previously validated. Verification independently provides evidence that an analytical procedure fulfils concordance with laboratory assays, imprecision, and hemolysis interference requirements. Methods Five whole blood samples span...

Introduction Clinical assessment in emergency departments (EDs) for possible acute myocardial infarction (AMI) requires at least one cardiac troponin (cTn) blood test. The turn-around time from blood draw to posting results in the clinical portal for central laboratory analysers is ~1–2 hours. New generation, high-sensitivity, point-of-care cardiac...

Background Clinical decision-making for risk stratification for possible myocardial infarction (MI) uses high-sensitivity cardiac troponin (hs-cTn) thresholds that range from the limit of detection to several-fold higher than the upper reference limit (URL). To establish a minimum analytical variation standard, we can quantify the effect of variati...

Background Growth differentiation factor-15 (GDF-15) has been shown to be associated with adverse clinical outcomes in patients after an acute coronary syndrome when measured soon after an event. Although dynamic in the acute phase after myocardial injury, GDF-15 has been shown to remain stable during convalescence. In this study, we aimed to asses...

An infographic about our recent paper in EMJ

Background: Single-sample (screening) rule-out of acute myocardial infarction (AMI) with troponin requires derivation of a single-test screening threshold. In data sets with small event numbers, the lowest one or two concentrations of myocardial infarction (MI) patients dictate the threshold. This is not optimal. We aimed to demonstrate a process...

Background Novel creatinine-based equations have recently been proposed but their predictive performance for cardiovascular outcomes in participants at high cardiovascular risk in comparison to the established CKD-EPI 2009 equation is unknown. Methods In 9,361 participants from the United States included in the randomized controlled SPRINT trial,...

Background Markers of adverse left ventricular remodelling following myocardial infarction are associated with an increased risk of adverse events. Remodelling patterns can be classified using left ventricular mass index (LVMI) and relative wall thickness (RWT) into normal geometry, eccentric hypertrophy, concentric remodelling and concentric hyper...

Background Cardiac troponin-immunoglobulin (Ig) complexes (macrotroponin) can interfere with cardiac troponin (cTn) test performance. However, the role of this interference has not been fully explored. We developed a specific, novel, 2-hour prototype immunoassay of monomer IgG-bound TnI (bTnI-IgG). Using this assay, our purpose was to examine the p...

Rapid Response to Meir et al. Comparing the U<lity of Clinical Risk Scores and Integrated Clinical Judgment in Pa<ents with Suspected Acute Coronary Syndrome Dear Dr Vranckx, We congratulate Meier et al 1 on asking the valid quesEon of whether risk scores are now of value in ED with the advent of high-sensiEvity troponin assays. However, it is not...

Objectives: Anticholinergic burden is detrimental to cognitive health. Multiple studies found that a high anticholinergic burden is associated with an increased risk for dementia, changes to the brain structure, function, and cognitive decline. We performed a post hoc analysis of a randomized controlled deprescribing trial. We compared the effect...

Background Older people have more comorbidities than younger groups and multimorbidity will increase. Often chronic conditions affect quality of life, functional ability and social participation. Our study aim was to quantify the prevalence of chronic conditions over a three-year period and their association with mortality after accounting for demo...

Although guidelines recommend fixed cardiac troponin thresholds for the diagnosis of myocardial infarction, troponin concentrations are influenced by age, sex, comorbidities and time from symptom onset. To improve diagnosis, we developed machine learning models that integrate cardiac troponin concentrations at presentation or on serial testing with...

Objective: Atrial fibrillation/flutter (AF/AFL) accounts for high rates of ED presentations and hospital admissions. There is increasing evidence to suggest that delaying cardioversion for acute uncomplicated AF is safe, and that many patients will spontaneously revert to sinus rhythm (SR). We conducted a before-and-after evaluation of AF/AFL mana...

Background: In suspected myocardial infarction (MI), guidelines recommend using high-sensitivity cardiac troponin (hs-cTn)-based approaches. These require fixed assay-specific thresholds and timepoints, without directly integrating clinical information. Using machine-learning techniques including hs-cTn and clinical routine variables, we aimed to...

Background Patients suffering from acute myocardial infarction (AMI) are at risk of secondary outcomes including major adverse cardiovascular events (MACE) and heart failure (HF). Comprehensive molecular phenotyping and cardiac imaging during the post-discharge time window may provide cues for risk stratification for the outcomes. Materials and me...

Mass spectrometry is a powerful technique for investigating renal pathologies and identifying biomarkers, and efficient protein extraction from kidney tissue is essential for bottom-up proteomic analyses. Detergent-based strategies aid cell lysis and protein solubilization but are poorly compatible with downstream protein digestion and liquid chrom...

On 26 September 2022 the Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, a satellite of the asteroid 65803 Didymos. Because it is a binary system, it is possible to determine how much the orbit of the satellite changed, as part of a test of what is necessary to deflect an asteroid that might threaten Earth with an impact. In...

On 26 September 2022 the Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, a satellite of the asteroid 65803 Didymos1. Because it is a binary system, it is possible to determine how much the orbit of the satellite changed, as part of a test of what is necessary to deflect an asteroid that might threaten Earth with an impact. In...

Machine learning in cardiology is becoming more commonplace in the medical literature; however, machine learning models have yet to result in a widespread change in practice. This is partly due to the language used to describe machine, which is derived from computer science and may be unfamiliar to readers of clinical journals. In this narrative re...

Introduction The rural accelerated chest pain pathway (RACPP) has been shown to safely reduce the number of transfers to hospital for patients who present with chest pain to rural general practice. Aim This study aimed to estimate the costs associated with assessing patients with low-risk chest pain using the RACPP in rural general practice compare...

Background: Polypharmacy is associated with poor outcomes in older adults. Targeted deprescribing of anticholinergic and sedative medications may improve health outcomes for frail older adults. Our pharmacist-led deprescribing intervention was a pragmatic two-arm randomized controlled trial stratified by frailty. We compared usual care (control) w...

Introduction The rural accelerated chest pain pathway (RACPP) has been shown to safely reduce the number of transfers to hospital for patients who present with chest pain to rural general practice. Aim This study aimed to estimate the costs associated with assessing patients with low-risk chest pain using the RACPP in rural general practice compar...

The ability to accurately predict the one-year survival of older adults is challenging for clinicians as they endeavour to provide the most appropriate care. Standardised clinical needs assessments are routine in many countries and some enable application of mortality prediction models. The added value of blood biomarkers to these models is largely...

Introduction: Blood-based diagnostics and prognostics in sporadic Alzheimer's disease (AD) are important for identifying at-risk individuals for therapeutic interventions. Methods: In three stages, a total of 34 leukocyte antigens were examined by flow cytometry immunophenotyping. Data were analyzed by logistic regression and receiver operating...

Background Elevations of high-sensitivity cardiac troponin (hs-cTn) concentrations not related to type 1 myocardial infarction are common in chest pain patients presenting to emergency departments. The discrimination of these patients from those with type 1 myocardial infarction (MI) is challenging and resource-consuming. We aimed to investigate wh...

Background Guidelines recommend fixed cardiac troponin thresholds for the assessment of patients with suspected acute coronary syndrome, however, performance varies in important patient groups as concentrations are influenced by age, sex and comorbidities. This limitation can be addressed using machine learning algorithms. Methods Machine learning...

https://tinyurl.com/4z55vvnk - In Receiver Operating Characteristic (ROC) plots, the main diagonal is often referred to as “chance” or the “random line”. In general, however, this does not correspond to the layperson’s concept of chance or randomness for binary outcomes. Rather, this represents a special case of layperson’s chance, or the ROC curve...

Background a Frailty Index (FI) calculated by the accumulation of deficits is often used to quantify the extent of frailty in individuals in specific settings. This study aimed to derive a FI that can be applied across three standardised international Residential Assessment Instrument assessments (interRAI), used at different stages of ageing and t...

The Unistellar network, composed of 10,000 digital, smart and easy-to-use telescopes 1,2 distributed worldwide was used to follow the James Webb Space Telescope (JWST) on its way to the Lagrange point from December 2021 to March 2022. The motivation of this campaign, led and organized by researchers at the SETI Institute, is twofold: 1. Provide acc...

We present a coordinated campaign of observations to monitor the brightness of the James Webb Space Telescope (JWST) as it travels toward the second Earth-Sun Lagrange point and unfolds using the network ofUnistellar digital telescopes. Those observations collected by citizen astronomers across the world allowed us to detect specific phases such as...

Background Diagnostic pathways for myocardial infarction rely on fixed troponin thresholds, which do not recognise that troponin varies by age, sex, and time within individuals. To overcome this limitation, we recently introduced a machine learning algorithm that predicts the likelihood of myocardial infarction. Our aim was to evaluate whether this...

Background Prognostic biomarkers for patients admitted for a myocardial infarction (MI) episode are of great interest for risk stratification and follow-up care after discharge. Multi-omics analysis is a standard approach for the discovery of diagnostic and prognostic biomarkers, but few studies have evaluated the prognostic potential of molecular...

Aims Most rural hospitals and general practices in New Zealand (NZ) are reliant on point-of-care troponin. A rural accelerated chest pain pathway (RACPP), combining an electrocardiogram (ECG), a structured risk score (Emergency Department Assessment of Chest Pain Score), and serial point-of-care troponin, was designed for use in rural hospital and...

Objectives To assess the feasibility and acceptability, and additionally to preliminarily evaluate, the effectiveness and safety of an accelerated diagnostic chest pain pathway in rural general practice using point-of-care troponin to identify patients at low risk of acute myocardial infarction, avoiding unnecessary patient transfer to hospital and...

One-quarter of patients with acute decompensated heart failure (ADHF) experience acute kidney injury (AKI)—an abrupt reduction or loss of kidney function associated with increased long-term mortality. There is a critical need to identify early and real-time markers of AKI in ADHF; however, to date, no protein biomarkers have exhibited sufficient di...

Background CT performed within 6 hours of headache onset is highly sensitive for the detection of subarachnoid haemorrhage (SAH). Beyond this time frame, if the CT is negative for blood, a lumbar puncture is often performed. Technology improvements in image noise reduction, resolution and motion artefact have enhanced the performance of multislice...

Background: The 2020 European Society of Cardiology (ESC) guidelines recommend using the 0/1-hour and 0/2-hour algorithms over the 0/3-hour algorithm as the first and second choices of high-sensitivity cardiac troponin (hs-cTn)-based strategies for triage of patients with suspected acute myocardial infarction (AMI). Purpose: To evaluate the diag...

Background Targeted deprescribing of anticholinergic and sedative medications in older people may improve their health outcomes. This trial will determine if pharmacist-led reviews lead to general practitioners deprescribing anticholinergic and sedative medications in older people living in the community. Methods and analysis The standard protocol...

Aim To develop a machine learning model to predict the diagnosis of pulmonary embolism (PE). Methods and results We undertook a derivation and internal validation study to develop a risk prediction model for use in patients being investigated for possible PE. The machine learning technique, generalized logistic regression using elastic net, was ch...

Acute decompensated heart failure (ADHF) is associated with a high incidence of acute kidney injury (AKI), an abrupt loss of kidney function associated with a near doubling of mortality at 1 year. In addition to the direct threat acute HF itself poses to kidney function, the beneficial effects of commonly prescribed HF treatments must be weighed ag...

Takes the output of an exoplanet transit from the EXOTIC (EXOplanet Transit Interpretation Code) and makes an animate gif of the transit. See E.G.: https://twitter.com/kiwiskiNZ/status/1433228065572753408

Background: Targeted deprescribing of anticholinergic and sedative medications in older people can improve their health outcomes. This trial will determine if pharmacist-led reviews lead to general practitioners deprescribing anticholinergic and sedative medications in older people living in the community. Methods and analysis: The Standard Protoc...

A method to understand the difference between two P values.

Background: Chest pain indicating acute coronary syndrome (ACS) accounts for approximately 5-10% of presents in the emergency departments (EDs). Rapid decision making is very important because longer hospital stay is associated with higher financial burden. The aim of this study was to compare current practice with a 2-hour accelerated diagnostic...

The COVID-19 pandemic raised major concerns relating to hospital capacity and cross-infection patients and staff in the Emergency Department (ED) of a metropolitan hospital servicing a population of ~500,000. We determined to reduce length of stay and admissions in patients presenting with symptoms of possible myocardial infarction; the most common...

Background Currently, one-year survival of older people with complex co-morbidities is unpredictable. Identifying older adults with a reduced life expectancy will lead to more targeted care and better healthcare resource allocation. Methods Development and validation of one-year and three-month mortality risks in people aged ≥65 years who had comp...

Introduction The myocardial-ischemic-injury-index (MI3) is a promising machine learned algorithm that predicts the likelihood of myocardial infarction in patients with suspected acute coronary syndrome. Whether this algorithm performs well in unselected patients or predicts recurrent events is unknown. Methods In an observational analysis from a m...

Background Little is known about the prevalence of frailty in indigenous populations. We developed a frailty index for older New Zealand Māori and Pasifika who require publicly funded support services. Methods A frailty index (FI) was developed for New Zealand adults aged ≥65 years who had an interRAI-Home Care assessment between 1 June 2012 and 3...

Background: Heart failure (HF) is the most common long-term complication of acute myocardial infarction (MI). Understanding plasma proteins associated with post-MI HF and their gene expression may identify new candidates for biomarker and drug target discovery. Methods: We employed aptamer-based affinity-capture plasma proteomics to measure 1305 pl...

Background: Heart failure is a common condition in older people with complex medical needs. A key factor in resilience after heart failure is the capacity to perform the instrumental activities of daily living (IADLs). Knowing the association between capacity to perform IADLs and entry into aged residential care will help health professionals plan...

Objectives The objectives of this study were to identify variables associated with dementia and entry into aged residential care (ARC) and derive and validate a risk prediction model for dementia and entry into ARC. Design This was an observational study of prospectively collected Home Care International Residential Assessment Instrument (interRAI...