Tracey Hawkins

Two-Hour Algorithm for Triage toward Rule-Out and Rule-In of Acute Myocardial Infarction by Use of High-Sensitivity Cardiac Troponin I

BACKGROUND The early triage of patients toward rule-out and rule-in of acute myocardial infarction (AMI) is challenging. Therefore, we aimed to develop a 2-h algorithm that uses high-sensitivity cardiac troponin I (hs-cTnI). METHODS We prospectively enrolled 1435 (derivation cohort) and 1194 (external validation cohort) patients presenting with suspected AMI to the emergency department. The final diagnosis was adjudicated by 2 independent cardiologists. hs-cTnI was measured at presentation and after 2 h in a blinded fashion. We derived and validated a diagnostic algorithm incorporating hs-cTnI values at presentation and absolute changes within the first 2 h. RESULTS AMI was the final diagnosis in 17% of patients in the derivation and 13% in the validation cohort. The 2-h algorithm developed in the derivation cohort classified 56% of patients as rule-out, 17% as rule-in, and 27% as observation. Resulting diagnostic sensitivity and negative predictive value (NPV) were 99.2% and 99.8% for rule-out; specificity and positive predictive value (PPV) were 95.2% and 75.8% for rule-in. Applying the 2-h algorithm in the external validation cohort, 60% of patients were classified as rule-out, 13% as rule-in, and 27% as observation. Diagnostic sensitivity and NPV were 98.7% and 99.7% for rule-out; specificity and PPV were 97.4% and 82.2% for rule-in. Thirty-day survival was 100% for rule-out patients in both cohorts. CONCLUSIONS A simple algorithm incorporating hs-cTnI baseline values and absolute 2-h changes allowed a triage toward safe rule-out or accurate rule-in of AMI in the majority of patients.

Cost and outcomes of assessing patients with chest pain in an Australian emergency department.

Objectives: We sought to characterise the demographics, length of admission, final diagnoses, long‐term outcome and costs associated with the population who presented to an Australian emergency department (ED) with symptoms of possible acute coronary syndrome (ACS).

Examining the signs and symptoms experienced by individuals with suspected acute coronary syndrome in the Asia-pacific region: A prospective observational study

STUDY OBJECTIVE This study examines whether symptoms reported by patients presenting with possible acute coronary syndrome vary across different ethnic backgrounds. We also assess the predictive value of individual symptoms according to ethnic background. METHODS The study used prospectively collected data on adult patients presenting with suspected acute coronary syndrome to 12 emergency departments in the Asia-Pacific region. Trained research nurses collected data on ethnicity, type of pain, and associated symptoms, using a customized case report form. The primary endpoint was acute coronary syndrome within 30 days of presentation, as adjudicated by cardiologists using standardized guidelines. Logistic regression analyses assessed the relationship between ethnicity and symptom type and the predictive value of symptom type for acute coronary syndrome. RESULTS Acute coronary syndrome was diagnosed in 358 (19.2%) of the 1,868 patients recruited. In comparison with white patients, Chinese patients were less likely to report atypical pain (odds ratio [OR]=0.26; 95% confidence interval [CI] 0.2 to 0.34), exertional pain (OR=0.41; 95% CI 0.32 to 0.53), pleuritic pain (OR=0.26; 95% CI 0.19 to 0.35), pain on palpation (OR=0.31; 95% CI 0.2 to 0.49), nausea (OR=0.52; 95% CI 0.42 to 0.67), diaphoresis (OR=0.41; 95% CI 0.33 to 0.51), and shortness of breath (OR=0.59; 95% CI 0.48 to 0.73). The comparison of white with other ethnic groups yielded similar results. The predictive value of symptoms was similarly poor across different ethnic groups, with the notable exception of India, where typical pain was predictive of acute coronary syndrome (OR 8.82; 95% CI 2.19 to 35.48). CONCLUSION There are cross-cultural differences in symptoms reported by patients with suspected acute coronary syndrome. Such differences are not likely to be clinically relevant because the majority of symptoms display limited diagnostic value for acute coronary syndrome.

Validation of NICE diagnostic guidance for rule out of myocardial infarction using high-sensitivity troponin tests

Objective To validate the National Institute for Health and Care Excellence (NICE) recommended algorithms for high-sensitivity troponin (hsTn) assays in adults presenting with chest pain. Methods International post hoc analysis of three prospective, observational studies from tertiary hospital emergency departments. The primary endpoint was cardiac death or acute myocardial infarction (AMI) within 24 hours of presentation, and the secondary endpoint was major adverse cardiac events (MACE) at 30 days. Results 15% of patients were diagnosed with non-ST elevation myocardial infarction (MI) on admission. The hsTnI algorithm classified 2506/3128 (80.1%) of patients as ‘ruled out’ with 50 (2.0%) missed MI. 943/3128 (30.1%) of patients had a troponin I level below the limit of detection on admission with 2 (0.2%) missed MI. For the hsTnT algorithm, 1794/3374 (53.1%) of patients were ‘ruled out’ with 7 (0.4%) missed MI. 490/3374 (14.5%) of patients had a troponin T below the limit of blank on admission with no MI. MACE at 30 days occurred in 10.7% and 8.5% of patients ‘ruled out’ defined by the hsTnI and hsTnT algorithms, respectively. Conclusions The NICE algorithms could identify patients with low probability of AMI within 2 hours; however, neither strategy performed as predicted by the NICE diagnostic guidance model. Additionally, the rate of MACE at 30 days was sufficiently high that the algorithms should only be used as one component of a more extensive model of risk stratification. Trial registration number ACTRN12611001069943, NCT00470587; post-results.

Improved Assessment of Chest pain Trial (IMPACT): assessing patients with possible acute coronary syndromes

Objective: To examine the safety and efficacy of the Improved Assessment of Chest pain Trial (IMPACT) protocol, a strategy for accelerated assessment of patients presenting to emergency departments (EDs) with chest pain.

Evaluating Rapid Rule-out of Acute Myocardial Infarction by Use of a High-Sensitivity Cardiac Troponin I Assay at Presentation

BACKGROUND Low concentrations of cardiac troponin (cTn) have been recommended for rapid rule-out of acute myocardial infarction (AMI). We examined the Beckman Coulter Access high-sensitivity cardiac troponin I (hs-cTnI) assay to identify a single test threshold that can safely rule out AMI. METHODS This analysis used stored samples collected in 2 prospective observational studies. In all, 1871 patients presenting to a tertiary emergency department with symptoms of acute coronary syndrome had blood taken for measurement of cTnI on presentation. The endpoint was type 1 myocardial infarction (T1MI). Sensitivity and negative predictive value (NPV) were calculated for hs-cTnI values below the 99th percentile. RESULTS Ninety-eight patients had T1MI (5.2%), and 638 (34.1%) patients had an hs-cTnI <2 ng/L (limit of detection), with sensitivity of 99.0% (95% CI, 94.4%-100%) and NPV of 99.8% (95% CI, 99.1%-100%). No hs-cTnI value above a concentration of 2 ng/L achieved sensitivity of 99%. However, an NPV of 99.5% was achieved at values <6 ng/L. A cutoff <6 ng/L enabled 1475 (78.8%) patients to be ruled out on presentation with sensitivity of 93.9% (95% CI, 87.1%-97.7%). CONCLUSIONS A single baseline cTn <2 ng/L measured with the Access hs-cTnI assay performed well for rule-out of AMI. This cutoff concentration identified 99% of patients with AMI and could reduce the number of patients requiring lengthy assessment. A cutoff of <6 ng/L yielded a high NPV but missed more cases of AMI than would be acceptable to clinicians.

Differences in presentation, management and outcomes in women and men presenting to an emergency department with possible cardiac chest pain

BACKGROUND Research suggests that female patients with acute coronary syndrome (ACS) experience delays in emergency department (ED) management and are less likely to receive guideline-based treatments and referrals for follow-up testing. Women are often found to have poorer clinical outcomes in comparison to men. This study aimed to assess current sex differences in the presentation, management and outcomes of patients with undifferentiated chest pain presenting to a tertiary ED. METHODS Data were analysed from two prospective studies conducted at a single Australian site between 2007 and 2014. Eligible patients were those of 18 years of age or older presenting with at least 5 minutes of chest pain or other symptoms for which the treating physician planned to investigate for possible ACS. Presenting symptoms, ED time measures, follow-up testing and outcomes, including 30-day ACS and mortality, were measured and compared between male and female patients. RESULTS Of 2349 (60% men) patients presenting with chest pain, 153 men and 51 women were diagnosed with ACS within 30days . Presenting symptoms were similar in men and women with confirmed ACS. Time from symptom onset to ED presentation, time spent in the ED and total time in hospital were similar between the sexes. Male and female patients had similar rates of follow-up provocative testing. After adjustment for clinical factors, the odds of undergoing angiography were 1.8 (95% CI: 1.36-2.40) times higher for men than women. Of those undergoing coronary angiography within 30 days, a smaller proportion of women, compared to men, received revascularisation. Within 30 days, three (0.2%) male and one (0.1%) female patient died. CONCLUSION Minimal sex differences were observed in the contemporary emergency management of patients presenting with suspected ACS. Thirty-day outcomes were similarly low in men and women despite lower rates of coronary angiography and revascularisation in women. Further research is required to replicate these results in different hospital systems and cultural settings.

Factors influencing choice of pre-hospital transportation of patients with potential acute coronary syndrome: an observational study

To determine factors associated with ambulance use in patients with confirmed and potential acute coronary syndrome presenting to the ED.

Diagnostic Accuracy of a New High-Sensitivity Troponin I Assay and Five Accelerated Diagnostic Pathways for Ruling Out Acute Myocardial Infarction and Acute Coronary Syndrome

Study objective: This diagnostic accuracy study describes the performance of 5 accelerated chest pain pathways, calculated with the new Beckmans Access high‐sensitivity troponin I assay. Methods: High‐sensitivity troponin I was measured with presentation and 2‐hour blood samples in 1,811 patients who presented to an emergency department (ED) in Australia. Patients were classified as being at low risk according to 5 rules: modified accelerated diagnostic protocol to assess patients with chest pain symptoms using troponin as the only biomarker (m‐ADAPT), the Emergency Department Assessment of Chest Pain Score (EDACS) pathway, the History, ECG, Age, Risk Factors, and Troponin (HEART) pathway, the No Objective Testing Rule, and the new Vancouver Chest Pain Rule. Endpoints were 30‐day acute myocardial infarction and acute coronary syndrome. Measures of diagnostic accuracy for each rule were calculated. Results: Data included 96 patients (5.3%) with acute myocardial infarction and 139 (7.7%) with acute coronary syndrome. The new Vancouver Chest Pain Rule and No Objective Testing Rule had high sensitivity for acute myocardial infarction (100%; 95% confidence interval [CI] 96.2% to 100% for both) and acute coronary syndrome (98.6% [95% CI 94.9% to 99.8%] and 99.3% [95% CI 96.1% to 100%]). The m‐ADAPT, EDACS, and HEART pathways also yielded high sensitivity for acute myocardial infarction (96.9% [95% CI 91.1% to 99.4%] for m‐ADAPT and 97.9% [95% CI 92.7% to 99.7%] for EDACS and HEART), but lower sensitivity for acute coronary syndrome (≤95.0% for all). The m‐ADAPT, EDACS, and HEART rules classified more patients as being at low risk (64.3%, 62.5%, and 49.8%, respectively) than the new Vancouver Chest Pain Rule and No Objective Testing Rule (28.2% and 34.5%, respectively). Conclusion: In this cohort with a low prevalence of acute myocardial infarction and acute coronary syndrome, using the Beckmans Access high‐sensitivity troponin I assay with the new Vancouver Chest Pain Rule or No Objective Testing Rule enabled approximately one third of patients to be safely discharged after 2‐hour risk stratification with no further testing. The EDACS, m‐ADAPT, or HEART pathway enabled half of ED patients to be rapidly referred for objective testing.

Prospective validation of prognostic and diagnostic syncope scores in the emergency department

BACKGROUND Various scores have been derived for the assessment of syncope patients in the emergency department (ED) but stay inconsistently validated. We aim to compare their performance to the one of a common, easy-to-use CHADS2 score. METHODS We prospectively enrolled patients ≥ 40 years old presenting with syncope to the ED in a multicenter study. Early clinical judgment (ECJ) of the treating ED-physician regarding the probability of cardiac syncope was quantified. Two independent physicians adjudicated the final diagnosis after 1-year follow-up. Major cardiovascular events (MACE) and death were recorded during 2 years of follow-up. Nine scores were compared by their area under the receiver-operator characteristics curve (AUC) for death, MACE or the diagnosis of cardiac syncope. RESULTS 1490 patients were available for score validation. The CHADS2-score presented a higher or equally high accuracy for death in the long- and short-term follow-up than other syncope-specific risk scores. This score also performed well for the prediction of MACE in the long- and short-term evaluation and stratified patients with accuracy comparative to OESIL, one of the best performing syncope-specific risk score. All scores performed poorly for diagnosing cardiac syncope when compared to the ECJ. CONCLUSIONS The CHADS2-score performed comparably to more complicated syncope-specific risk scores in the prediction of death and MACE in ED syncope patients. While better tools incorporating biochemical and electrocardiographic markers are needed, this study suggests that the CHADS2-score is currently a good option to stratify risk in syncope patients in the ED. TRIAL REGISTRATION NCT01548352.