Dylan Flaws

2-Hour accelerated diagnostic protocol to assess patients with chest pain symptoms using contemporary troponins as the only biomarker: the ADAPT trial.

OBJECTIVES The purpose of this study was to determine whether a new accelerated diagnostic protocol (ADP) for possible cardiac chest pain could identify low-risk patients suitable for early discharge (with follow-up shortly after discharge). BACKGROUND Patients presenting with possible acute coronary syndrome (ACS), who have a low short-term risk of adverse cardiac events may be suitable for early discharge and shorter hospital stays. METHODS This prospective observational study tested an ADP that included pre-test probability scoring by the Thrombolysis In Myocardial Infarction (TIMI) score, electrocardiography, and 0 + 2 h values of laboratory troponin I as the sole biomarker. Patients presenting with chest pain due to suspected ACS were included. The primary endpoint was major adverse cardiac event (MACE) within 30 days. RESULTS Of 1,975 patients, 302 (15.3%) had a MACE. The ADP classified 392 patients (20%) as low risk. One (0.25%) of these patients had a MACE, giving the ADP a sensitivity of 99.7% (95% confidence interval [CI]: 98.1% to 99.9%), negative predictive value of 99.7% (95% CI: 98.6% to 100.0%), specificity of 23.4% (95% CI: 21.4% to 25.4%), and positive predictive value of 19.0% (95% CI: 17.2% to 21.0%). Many ADP negative patients had further investigations (74.1%), and therapeutic (18.3%) or procedural (2.0%) interventions during the initial hospital attendance and/or 30-day follow-up. CONCLUSIONS Using the ADP, a large group of patients was successfully identified as at low short-term risk of a MACE and therefore suitable for rapid discharge from the emergency department with early follow-up. This approach could decrease the observation period required for some patients with chest pain. (An observational study of the diagnostic utility of an accelerated diagnostic protocol using contemporary central laboratory cardiac troponin in the assessment of patients presenting to two Australasian hospitals with chest pain of possible cardiac origin; ACTRN12611001069943).

Development and validation of the Emergency Department Assessment of Chest pain Score and 2 h accelerated diagnostic protocol

Risk scores and accelerated diagnostic protocols can identify chest pain patients with low risk of major adverse cardiac event who could be discharged early from the ED, saving time and costs. We aimed to derive and validate a chest pain score and accelerated diagnostic protocol (ADP) that could safely increase the proportion of patients suitable for early discharge.

A cross-sectional analysis of patterns of obesity in a cohort of working nurses and midwives in Australia, New Zealand, and the United Kingdom

OBJECTIVE The aim of this study was to examine the prevalence of overweight and obesity and the association with demographic, reproductive work variables in a representative cohort of working nurses and midwives. DESIGN A cross sectional study of self reported survey data. SETTINGS Australia, New Zealand and the United Kingdom. METHODS Measurement outcomes included BMI categories, demographic (age, gender, marital status, ethnicity), reproductive (parity, number of births, mothers age at first birth, birth type and menopausal status) and workforce (registration council, employment type and principal specialty) variables. PARTICIPANTS 4996 respondents to the Nurses and Midwives e-Cohort study who were currently registered and working in nursing or midwifery in Australia (n=3144), New Zealand (n=778) or the United Kingdom (n=1074). RESULTS Amongst the sample 61.87% were outside the healthy weight range and across all three jurisdictions the prevalence of obesity in nurses and midwives exceeded rates in the source populations by 1.73% up to 3.74%. Being overweight or obese was significantly associated with increasing age (35-44 yrs aOR 1.71, 95% CI 1.41-2.08; 45-55 yrs aOR 1.90, 95%CI 1.56-2.31; 55-64 aOR 2.22, 95% CI 1.71-2.88), and male gender (aOR 1.46, 95% CI 1.15-1.87). Primiparous nurses and midwives were more likely to be overweight or obese (aOR 1.37, 95% CI 1.06-1.76) as were those who had reached menopause (aOR 1.37, 95% CI 1.11-1.69). Nurses and midwives in part-time or casual employment had significantly reduced risk of being overweight or obese, (aOR 0.81, 95% CI 0.70-0.94 and aOR 0.75, 95% CI 0.59-0.96 respectively), whilst working in aged carried increased risk (aOR 1.37, 95% CI 1.04-1.80). CONCLUSION Nurses and midwives in this study have higher prevalence of obesity and overweight than the general population and those who are older, male, or female primiparous and menopausal have significantly higher risk of overweight or obesity as do those working fulltime, or in aged care. The consequences of overweight and obesity in this occupational group may impact on their workforce participation, their management of overweight and obese patients in their care as well as influencing their individual health behaviours and risks of occupational injury and chronic disease.

Assessment of the European society of cardiology 0-hour/1-hour algorithm to rule-out and rule-in acute myocardial infarction

Background: The new European Society of Cardiology guidelines to rule-in and rule-out acute myocardial infarction (AMI) in the emergency department include a rapid assessment algorithm based on high-sensitivity cardiac troponin and sampling at 0 and 1 hour. Emergency department physicians require high sensitivity to confidently rule-out AMI, whereas cardiologists aim to minimize false-positive results. Methods: High-sensitivity troponin I and T assays were used to measure troponin concentrations in patients presenting with chest-pain symptoms and being investigated for possible acute coronary syndrome at hospitals in New Zealand, Australia, and Canada. AMI outcomes were independently adjudicated by at least 2 physicians. The European Society of Cardiology algorithm performance with each assay was assessed by the sensitivity and proportion with AMI ruled out and the positive predictive value and proportion ruled-in. Results: There were 2222 patients with serial high-sensitivity troponin T and high-sensitivity troponin I measurements. The high-sensitivity troponin T algorithm ruled out 1425 (64.1%) with a sensitivity of 97.1% (95% confidence interval [CI], 94.0%–98.8%) and ruled-in 292 (13.1%) with a positive predictive value of 63.4% (95% CI, 57.5%–68.9%). The high-sensitivity troponin I algorithm ruled out 1205 (54.2%) with a sensitivity of 98.8% (95% CI, 96.4%–99.7%)) and ruled-in 310 (14.0%) with a positive predictive value of 68.1% (95% CI, 62.6%–73.2%). Conclusions: The sensitivity of the European Society of Cardiology rapid assessment 0-/1-hour algorithm to rule-out AMI with high-sensitivity troponin may be insufficient for some emergency department physicians to confidently send patients home. These algorithms may prove useful to identify patients requiring expedited management. However, the positive predictive value was modest for both algorithms.

Validation of presentation and 3 h high-sensitivity troponin to rule-in and rule-out acute myocardial infarction

Objective International guidelines to rule-in acute myocardial infarction (AMI) in patients presenting with chest pain to the emergency department (ED) recommend an algorithm using high-sensitivity cardiac troponin (hs-cTn) sampling on presentation and 3 h following presentation. We tested the diagnostic accuracy of this algorithm by pooling data from five distinct cohorts from three countries of prospectively recruited patients with independently adjudicated outcomes. Method We measured high-sensitivity cardiac troponin I (hs-cTnI) and high-sensitivity cardiac troponin T (hs-cTnT) on presentation (0 h) and 3 h post-presentation samples in adult patients attending an ED with possible AMI to validate the European Society of Cardiology (ESC) Working Group on Acute Cardiac Care rule-in algorithm (ESC-rule-in). Specifically, (i) in patients with a 0 h hs-cTn concentration ≤99th percentile and a 3 h hs-cTn >99th percentile, positive patients are those with an absolute change in troponin ≥50% of the 99th percentile, and (ii) in patients with a 0 and 3 h hs-cTn >99th percentile, positive patients are those with a relative change in troponin of ≥20%. We concurrently assessed the efficacy of the 0 and 3 h hs-cTn <99th percentile to rule-out AMI. Results 1061 patients with hs-cTnI and 985 with hs-cTnT were included. The ESC-rule-in positive predictive value (PPV) was 83.5% (95% CI 74.9% to 90.1%) for hs-cTnI and 72.0% (95% CI 62.1% to 80.5%) for hs-cTnT. Forty-six AMIs (34.9%) were not ruled in using hs-cTnI and 62 (46.2%) using hs-cTnT. The sensitivity of the 99th percentile to rule-out AMI was 93.2% (95% CI 87.5% to 96.8%) for hs-cTnI and 94.8% (95% CI 89.5% to 97.9%) for hs-cTnT. Conclusions The ESC-rule-in algorithm has good PPV with hs-cTnI and reasonable with hs-cTnT and can rule-in over 50% of AMIs. However, the sensitivity of the 99th percentile to rule-out AMI is too low for clinical use.

The new Vancouver Chest Pain Rule using troponin as the only biomarker: an external validation study

OBJECTIVES To externally evaluate the accuracy of the new Vancouver Chest Pain Rule and to assess the diagnostic accuracy using either sensitive or highly sensitive troponin assays. METHODS Prospectively collected data from 2 emergency departments (EDs) in Australia and New Zealand were analysed. Based on the new Vancouver Chest Pain Rule, low-risk patients were identified using electrocardiogram results, cardiac history, nitrate use, age, pain characteristics and troponin results at 2 hours after presentation. The primary outcome was 30-day diagnosis of acute coronary syndrome (ACS), including acute myocardial infarction, and unstable angina. Sensitivity, specificity, positive predictive values and negative predictive values were calculated to assess the accuracy of the new Vancouver Chest Pain Rule using either sensitive or highly sensitive troponin assay results. RESULTS Of the 1635 patients, 20.4% had an ACS diagnosis at 30 days. Using the highly sensitive troponin assay, 212 (13.0%) patients were eligible for early discharge with 3 patients (1.4%) diagnosed with ACS. Sensitivity was 99.1% (95% CI 97.4-99.7), specificity was 16.1 (95% CI 14.2-18.2), positive predictive values was 23.3 (95% CI 21.1-25.5) and negative predictive values was 98.6 (95% CI 95.9-99.5). The diagnostic accuracy of the rule was similar using the sensitive troponin assay. CONCLUSIONS The new Vancouver Chest Pain Rule should be used for the identification of low risk patients presenting to EDs with symptoms of possible ACS, and will reduce the proportion of patients requiring lengthy assessment; however we recommend further outpatient investigation for coronary artery disease in patients identified as low risk.

Comparison of new point-of-care troponin assay with high sensitivity troponin in diagnosing myocardial infarction

OBJECTIVES The aim of this study is to compare a new improved point of care cardiac troponin assay (new POC-cTnI) with 1. its predecessor (old POC-cTnI) and 2. a high sensitivity assay (hs-cTnI) for the diagnosis of acute myocardial infarction (AMI) and for major adverse cardiac events (MACE) by 30 days. METHODS This is a single centre observational study, set in Christchurch Hospital, New Zealand. Patients presenting to the emergency department with non-traumatic chest pain underwent blood sampling at 0 h and 2h post presentation for analysis with the 3 cTnI assays for the outcome of AMI and for analysis using an accelerated diagnostic protocol (ADP-normal 2h troponins, normal electrocardiograms and Thrombolysis In Myocardial Infarction (TIMI) score of 0 or ≤ 1) for 30 day MACE. RESULTS Of 962 patients, 220 (22.9%) had AMI. Old POC-cTnI was least sensitive at 70.0% (65.4-73.9%) by 2h (p<0.001). New POC-cTnI, sensitivity 93.6% (89.9-96.2%) had similar sensitivity to hs-cTnI, sensitivity 95.0% (91.5-97.3%) (p = 0.508). There were 231 (24.0%) patients with 30 day MACE. When used as part of the ADP, all assays had 100% (98.0-100%) sensitivity using TIMI = 0. Sensitivities of new POC-cTnI ADP, 98.3% (95.4-99.4%), old POC-cTnI, 96.5% (93.2-98.4%) and hs-cTnI, 98.7% (96.0-99.7%) were similar (p = 0.063-0.375) using TIMI ≤ 1. CONCLUSIONS A new POC-cTnI has improved sensitivity for AMI and MACE compared with its predecessor and comparable sensitivity to a high sensitivity assay. Now that sensitivities of the POC assay are improved, the new assay may be a useful alternative to central laboratory assays when rapid turn-around times are not possible.

External validation of the emergency department assessment of chest pain score accelerated diagnostic pathway (EDACS-ADP)

Objective The emergency department assessment of chest pain score accelerated diagnostic pathway (EDACS-ADP) facilitates low-risk ED chest pain patients early to outpatient investigation. We aimed to validate this rule in a North American population. Methods We performed a retrospective validation of the EDACS-ADP using 763 chest pain patients who presented to St Pauls Hospital, Vancouver, Canada, between June 2000 and January 2003. Patients were classified as low risk if they had an EDACS <16, no new ischaemia on ECG and non-elevated serial 0-hour and 2-hour cardiac troponin concentrations. The primary outcome was the number of patients who had a predetermined major adverse cardiac event (MACE) at 30 days after presentation. Results Of the 763 patients, 317 (41.6%) were classified as low risk by the EDACS-ADP. The sensitivity, specificity, negative predictive value and positive predictive value of the EDACS-ADP for 30-day MACE were 100% (95% CI 94.2% to 100%), 46.4% (95% CI 42.6% to 50.2%), 100% (95% CI 98.5% to 100.0%) and 17.5% (95% CI 14.1% to 21.3%), respectively. Conclusions This study validated the EDACS-ADP in a novel context and supports its safe use in a North American population. It confirms that EDACS-ADP can facilitate progression to early outpatient investigation in up to 40% of ED chest pain patients within 2 hours.

Simplification of a scoring system maintained overall accuracy but decreased the proportion classified as low risk

OBJECTIVES Scoring systems are developed to assist clinicians in making a diagnosis. However, their uptake is often limited because they are cumbersome to use, requiring information on many predictors, or complicated calculations. We examined whether, and how, simplifications affected the performance of a validated score for identifying adults with chest pain in an emergency department who have low risk of major adverse cardiac events. STUDY DESIGN AND SETTING We simplified the Emergency Department Assessment of Chest pain Score (EDACS) by three methods: (1) giving equal weight to each predictor included in the score, (2) reducing the number of predictors, and (3) using both methods--giving equal weight to a reduced number of predictors. The diagnostic accuracy of the simplified scores was compared with the original score in the derivation (n = 1,974) and validation (n = 909) data sets. RESULTS There was no difference in the overall accuracy of the simplified versions of the score compared with the original EDACS as measured by the area under the receiver operating characteristic curve (0.74 to 0.75 for simplified versions vs. 0.75 for the original score in the validation cohort). With score cut-offs set to maintain the sensitivity of the combination of score and tests (electrocardiogram and cardiac troponin) at a level acceptable to clinicians (99%), simplification reduced the proportion of patients classified as low risk from 50% with the original score to between 22% and 42%. CONCLUSION Simplification of a clinical score resulted in similar overall accuracy but reduced the proportion classified as low risk and therefore eligible for early discharge compared with the original score. Whether the trade-off is acceptable, will depend on the context in which the score is to be used. Developers of clinical scores should consider simplification as a method to increase uptake, but further studies are needed to determine the best methods of deriving and evaluating simplified scores.

Communicating diagnostic uncertainties to patients: The problems of explaining unclear diagnosis and risk

> Mr Kastagir attended his local emergency department with chest pain. Local data on prevalence suggests that the pretest probability of a patient with suspected cardiac chest pain having an acute coronary syndrome is approximately 25%.1 His physician is also aware that after serious disease has been excluded, the precise cause of the symptoms can often remain unclear. When a clinician sees a patient with an unclear presentation, 2 of the most important questions are (1) What is the exact diagnosis? (“What is the cause of my chest pain, doctor?”), and (2) What is the risk to the patient from the most potentially harmful differential diagnoses? (“Am I going to die from a heart attack?”) Both questions are important. However, clinicians and patients emphasise these questions differently. For example, patients may want to know the cause for their chest pain, while clinicians focus on the inclusion or exclusion of serious cardiac disease. If the clinician feels serious disease has been ruled out and tells the patient, the latter may still feel dissatisfied and worried because the cause of the pain has not been discovered. Explaining our uncertainty about diagnosis can be difficult, especially if having a causal “label” is important to the patient. Chest pain is a common acute presenting complaint in the emergency department. In our hospital, most patients presenting to the emergency department with acute chest pain are admitted,1 and, whether admitted or discharged, approximately 75% of patients are given the final diagnosis of “non-specific chest pain.” For attending clinicians, …