Interpretation of positive troponin results among patients with and without myocardial infarction.

Measuring cardiac troponins is integral to diagnosing acute myocardial infarction (AMI); however, troponins may be elevated without AMI, and the use of multiple different assays confounds comparisons. We considered characteristics and serial troponin values in emergency department chest pain patients with and without AMI to interpret troponin excursions. We compared serial troponin in 124 AMI and non-AMI patients from the observational Performance of Triage Cardiac Markers in the Clinical Setting (PEARL) study who presented with chest pain and had at least one troponin value exceeding the 99th percentile of normal. Because 8 assays were used during data collection, we employed a method of scaling the troponin value to the corresponding assay\u27s 99th percentile upper reference limit to standardize the results. In 81 AMI patients, 96% had elevated troponin at the first test following initial elevation, compared to 73% of the 43 non-AMI patients

Biomarkers Enhance Discrimination and Prognosis of Type 2 Myocardial Infarction

Background: The observed incidence of type 2 myocardial infarction (T2MI) is expected to increase with the implementation of increasingly sensitive cardiac troponin (cTn) assays. However, it remains to be determined how to diagnose, risk stratify and treat patients with T2MI. We aimed to discriminate and risk-stratify T2MI using biomarkers. Methods: Patients presenting to the Emergency Department with chest pain, enrolled in the CHOPIN study, were retrospectively analyzed. Two cardiologists adjudicated type 1 MI (T1MI) and T2MI. The prognostic ability of several biomarkers alone or in combination to discriminate T2MI from T1MI was investigated using receiver operating characteristic (ROC) curve analysis. The biomarkers analyzed were cTnI, copeptin, mid-regional pro-atrial natriuretic peptide (MRproANP), C-terminal pro-endothelin-1 (CT-proET1), mid-regional pro-adrenomedullin (MRproADM) and procalcitonin. Prognostic utility of these biomarkers for all-cause mortality and major adverse cardiovascular event (MACE: a composite of acute MI, unstable angina pectoris, reinfarction, heart failure, and stroke) at 180-day follow-up was also investigated. Results: Among the 2071 patients, T1MI and T2MI were adjudicated in 94 and 176 patients, respectively. Patients with T1MI had higher levels of baseline cTnI, while those with T2MI had higher baseline levels of MR-proANP, CT-proET1, MR-proADM, and procalcitonin. The area under the ROC curve (AUC) for the diagnosis of T2MI was higher for CT-proET1, MRproADM and MR-proANP (0.765, 0.750, and 0.733, respectively) than for cTnI (0.631). Combining all biomarkers resulted in a similar accuracy to a model using clinical variables and cTnI (0.854 versus 0.884, p = 0.294). Addition of biomarkers to the clinical model yielded the highest AUC (0.917). Other biomarkers, but not cTnI, were associated with mortality and MACE at 180-day among all patients, with no interaction between the diagnosis of T1MI or T2MI. Conclusions: Assessment of biomarkers reflecting pathophysiologic processes occurring with T2MI might help differentiate it from T1MI. Additionally, all biomarkers measured, except cTnI, were significant predictors of prognosis, regardless of type of MI

Utility of COVID-19 antigen testing in the emergency department

Background: The BinaxNOW coronavirus disease 2019 (COVID-19) Ag Card test (Abbott Diagnostics Scarborough, Inc.) is a lateral flow immunochromatographic point-of-care test for the qualitative detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein antigen. It provides results from nasal swabs in 15 minutes. Our purpose was to determine its sensitivity and specificity for a COVID-19 diagnosis. Methods: Eligible patients had symptoms of COVID-19 or suspected exposure. After consent, 2 nasal swabs were collected; 1 was tested using the Abbott RealTime SARS-CoV-2 (ie, the gold standard polymerase chain reaction test) and the second run on the BinaxNOW point of care platform by emergency department staff. Results: From July 20 to October 28, 2020, 767 patients were enrolled, of which 735 had evaluable samples. Their mean (SD) age was 46.8 (16.6) years, and 422 (57.4%) were women. A total of 623 (84.8%) patients had COVID-19 symptoms, most commonly shortness of breath (n = 404; 55.0%), cough (n = 314; 42.7%), and fever (n = 253; 34.4%). Although 460 (62.6%) had symptoms ≤7 days, the mean (SD) time since symptom onset was 8.1 (14.0) days. Positive tests occurred in 173 (23.5%) and 141 (19.2%) with the gold standard versus BinaxNOW test, respectively. Those with symptoms \u3e2 weeks had a positive test rate roughly half of those with earlier presentations. In patients with symptoms ≤7 days, the sensitivity, specificity, and negative and positive predictive values for the BinaxNOW test were 84.6%, 98.5%, 94.9%, and 95.2%, respectively. Conclusions: The BinaxNOW point-of-care test has good sensitivity and excellent specificity for the detection of COVID-19. We recommend using the BinasNOW for patients with symptoms up to 2 weeks

Finding acute coronary syndrome with serial troponin testing for rapid assessment of cardiac ischemic symptoms (FAST-TRAC): a study protocol.

ObjectiveTo determine the utility of a highly sensitive troponin assay when utilized in the emergency department.MethodsThe FAST-TRAC study prospectively enrolled >1,500 emergency department patients with suspected acute coronary syndrome within 6 hours of symptom onset and 2 hours of emergency department presentation. It has several unique features that are not found in the majority of studies evaluating troponin. These include a very early presenting population in whom prospective data collection of risk score parameters and the physician's clinical impression of the probability of acute coronary syndrome before any troponin data were available. Furthermore, two gold standard diagnostic definitions were determined by a pair of cardiologists reviewing two separate data sets; one that included all local troponin testing results and a second that excluded troponin testing so that diagnosis was based solely on clinical grounds. By this method, a statistically valid head-to-head comparison of contemporary and high sensitivity troponin testing is obtainable. Finally, because of a significant delay in sample processing, a unique ability to define the molecular stability of various troponin assays is possible.Trial registrationClinicalTrials.gov Identifier NCT00880802

Atherosclerotic plaque burden in cocaine users with acute chest pain:Analysis by coronary computed tomography angiography

<p>Chest pain associated with cocaine use represents an increasing problem in the emergency department (ED). Cocaine use has been linked to the acute coronary syndrome (ACS) and acute myocardial infarction (AMI). We used coronary computed tomography angiography (cCTA) to evaluate the prevalence, severity and composition of atherosclerotic lesions in cocaine users. We studied 78 patients with non-occasional cocaine use (52 men, 44 +/- 7 years, 23 under the acute influence) and acute chest pain but without ACS, who had undergone cCTA in the ED. Patients were matched one-to-one by gender, race, symptoms, and risk-factors with a control cohort (n = 78; 52 men, 45 +/- 6 years) not using cocaine. Each coronary segment was evaluated for the presence and composition (calcified, non-calcified, partially calcified) of atherosclerotic plaque and for stenosis. The prevalence of coronary stenosis was not significantly different between patients with and without cocaine use (13% versus 5%, P > 0.05). However, cocaine users on average had significantly more atherosclerotic plaques (0.44 +/- 0.88 versus 0.29 +/- 0.83, P <0.05) and a tendency towards more calcified (0.64 +/- 1.23 versus 0.55 +/- 1.22, P > 0.05) and non-calcified plaques (0.26 +/- 0.63 versus 0.17 +/- 0.57, P > 0.05), yet not reaching statistical significance. Furthermore, cocaine users had significantly more partially calcified plaques (0.41 +/- 0.61 versus 0.17 +/- 0.41, P <0.05) and higher partially calcified plaque volume (59.7 +/- 33.3 mm(3) versus 25.6 +/- 12.6 mm(3), P <0.05). Thus, cocaine users tend to have more pronounced coronary atherosclerosis compared to patients without cocaine use at the time of presentation with acute chest pain. (C) 2013 Elsevier Ireland Ltd. All rights reserved.</p>

Myocardial Infarction Can Be Safely Excluded by High-sensitivity Troponin I Testing 3 Hours After Emergency Department Presentation.

BackgroundThe accuracy and speed by which acute myocardial infarction (AMI) is excluded are an important determinant of emergency department (ED) length of stay and resource utilization. While high-sensitivity troponin I (hsTnI) &gt;99th percentile (upper reference level [URL]) represents a "rule-in" cutpoint, our purpose was to evaluate the ability of the Beckman Coulter hsTnI assay, using various level-of-quantification (LoQ) cutpoints, to rule out AMI within 3&nbsp;hours of ED presentation in suspected acute coronary syndrome (ACS) patients.MethodsThis multicenter evaluation enrolled adults with &gt;5&nbsp;minutes of ACS symptoms and an electrocardiogram obtained per standard care. Exclusions were ST-segment elevation or chronic hemodialysis. After informed consent was obtained, blood samples were collected in heparin at ED admission (baseline), ≥1 to 3, ≥3 to 6, and ≥6 to 9&nbsp;hours postadmission. Samples were processed and stored at -20°C within 1&nbsp;hour and were tested at three independent clinical laboratories on an immunoassay system (DxI 800, Beckman Coulter). Analytic cutpoints were the URL of 17.9&nbsp;ng/L and two LoQ cutpoints, defined as the 10 and 20% coefficient of variation (5.6 and 2.3&nbsp;ng/L, respectively). A criterion standard MI diagnosis was adjudicated by an independent endpoint committee, blinded to hsTnI, and using the universal definition of MI.ResultsOf 1,049 patients meeting the entry criteria, and with baseline and 1- to 3-hour hsTnI results, 117 (11.2%) had an adjudicated final diagnosis of AMI. AMI patients were typically older, with more cardiovascular risk factors. Median (IQR) presentation time was 4 (1.6-16.0)&nbsp;hours after symptom onset, although AMI patients presented ~0.5&nbsp;hour earlier than non-AMI. Enrollment and first blood draw occurred at a mean of ~1&nbsp;hour after arrival. To evaluate the assay's rule-out performance, patients with any hsTnI&nbsp;&gt;&nbsp;URL were considered high risk and were excluded. The remaining population (n&nbsp;=&nbsp;829) was divided into four LoQ relative categories: both hsTnI&nbsp;&lt;&nbsp;LoQ (Lo-Lo cohort); first hsTnI&nbsp;&lt;&nbsp;LoQ and 2nd&nbsp;&gt;&nbsp;LoQ (Lo-Hi cohort); first&nbsp;&gt;&nbsp;LoQ and second&nbsp;&lt;&nbsp;LoQ (Hi-Lo cohort); or both&nbsp;&gt;&nbsp;LoQ (Hi-Hi cohort). In patients with any hsTnI result &lt;20% CV LoQ (Groups 1-3), n&nbsp;=&nbsp;231 (23.9% ruled out), AMI negative predictive value (NPV)&nbsp;was&nbsp;100% (95% confidence interval [CI]&nbsp;= 98.9% to 100%). In patients with any hsTnI below the 10% LoQ, n&nbsp;=&nbsp;611 (58% rule out), AMI NPV&nbsp;was&nbsp;100% (95% CI&nbsp;= 99.5% to 100%). Of the Hi-Hi cohort (i.e., no hsTnI below the 10% LoQ, but both&nbsp;&lt;&nbsp;URL), there were four AMI patients, NPV&nbsp;was&nbsp;98.2% (95% CI&nbsp;= 95.4% to 99.3%), and sensitivity&nbsp;was&nbsp;96.6.ConclusionsPatients presenting &gt;3&nbsp;hours after the onset of suspected ACS symptoms, with at least two Beckman Coulter Access hsTnI&nbsp;&lt;&nbsp;URL and at least one of which is below either the 10 or the 20% LoQ, had a 100% NPV for AMI. Two hsTnI values 1 to 3&nbsp;hours apart with both&nbsp;&lt;&nbsp;URL, but also &gt;LoQ had inadequate sensitivity and NPV

Myocardial Infarction Can Be Safely Excluded by High-sensitivity Troponin I Testing 3 Hours After Emergency Department Presentation.

BACKGROUND: The accuracy and speed by which acute myocardial infarction (AMI) is excluded are an important determinant of emergency department (ED) length of stay and resource utilization. While high-sensitivity troponin I (hsTnI) \u3e99th percentile (upper reference level [URL]) represents a rule-in cutpoint, our purpose was to evaluate the ability of the Beckman Coulter hsTnI assay, using various level-of-quantification (LoQ) cutpoints, to rule out AMI within 3 hours of ED presentation in suspected acute coronary syndrome (ACS) patients. METHODS: This multicenter evaluation enrolled adults with \u3e5 minutes of ACS symptoms and an electrocardiogram obtained per standard care. Exclusions were ST-segment elevation or chronic hemodialysis. After informed consent was obtained, blood samples were collected in heparin at ED admission (baseline), ≥1 to 3, ≥3 to 6, and ≥6 to 9 hours postadmission. Samples were processed and stored at -20°C within 1 hour and were tested at three independent clinical laboratories on an immunoassay system (DxI 800, Beckman Coulter). Analytic cutpoints were the URL of 17.9 ng/L and two LoQ cutpoints, defined as the 10 and 20% coefficient of variation (5.6 and 2.3 ng/L, respectively). A criterion standard MI diagnosis was adjudicated by an independent endpoint committee, blinded to hsTnI, and using the universal definition of MI. RESULTS: Of 1,049 patients meeting the entry criteria, and with baseline and 1- to 3-hour hsTnI results, 117 (11.2%) had an adjudicated final diagnosis of AMI. AMI patients were typically older, with more cardiovascular risk factors. Median (IQR) presentation time was 4 (1.6-16.0) hours after symptom onset, although AMI patients presented ~0.5 hour earlier than non-AMI. Enrollment and first blood draw occurred at a mean of ~1 hour after arrival. To evaluate the assay\u27s rule-out performance, patients with any hsTnI \u3e URL were considered high risk and were excluded. The remaining population (n = 829) was divided into four LoQ relative categories: both hsTnI \u3c LoQ (Lo-Lo cohort); first hsTnI \u3c LoQ and 2nd \u3e LoQ (Lo-Hi cohort); first \u3e LoQ and second \u3c LoQ (Hi-Lo cohort); or both \u3e LoQ (Hi-Hi cohort). In patients with any hsTnI result CONCLUSIONS: Patients presenting \u3e3 hours after the onset of suspected ACS symptoms, with at least two Beckman Coulter Access hsTnI \u3c URL and at least one of which is below either the 10 or the 20% LoQ, had a 100% NPV for AMI. Two hsTnI values 1 to 3 hours apart with both \u3c URL, but also \u3eLoQ had inadequate sensitivity and NPV

Finding Acute Coronary Syndrome with Serial Troponin Testing for Rapid Assessment of Cardiac Ischemic Symptoms (FAST-TRAC): A Study Protocol

Objective: To determine the utility of a highly sensitive troponin assay when utilized in the emergency department. Methods: The FAST-TRAC study prospectively enrolled \u3e1,500 emergency department patients with suspected acute coronary syndrome within 6 hours of symptom onset and 2 hours of emergency department presentation. It has several unique features that are not found in the majority of studies evaluating troponin. These include a very early presenting population in whom prospective data collection of risk score parameters and the physician\u27s clinical impression of the probability of acute coronary syndrome before any troponin data were available. Furthermore, two gold standard diagnostic definitions were determined by a pair of cardiologists reviewing two separate data sets; one that included all local troponin testing results and a second that excluded troponin testing so that diagnosis was based solely on clinical grounds. By this method, a statistically valid head-to-head comparison of contemporary and high sensitivity troponin testing is obtainable. Finally, because of a significant delay in sample processing, a unique ability to define the molecular stability of various troponin assays is possible. Trial registration: ClinicalTrials.gov Identifier NCT00880802

Prognosis is worse with elevated cardiac troponin in nonacute coronary syndrome compared with acute coronary syndrome

Cardiac troponin (cTn) can be elevated in many patients presenting to the emergency department (ED) with chest pain but without a diagnosis of acute coronary syndrome (ACS). We compared the prognostic significance of cTn in these different populations.; We retrospectively analyzed the CHOPIN study, which enrolled patients who presented to the ED with chest pain. Patients were grouped as ACS, non-ACS cardiovascular disease, noncardiac chest pain and chest pain not otherwise specified (NOS). We examined the prognostic ability of cTnI for the clinical endpoints of mortality and major adverse cardiovascular event (MACE; a composite of acute myocardial infarction, unstable angina, revascularization, reinfarction, and congestive heart failure and stroke) at 180-day follow-up.; Among 1982 patients analyzed, 14% had ACS, 21% had non-ACS cardiovascular disease, 31% had a noncardiac diagnosis and 34% had chest pain NOS. cTnI elevation above the 99th percentile was observed in 52, 18, 6 and 7% in these groups, respectively. cTnI elevation was associated with mortality and MACE, and their relationships were more prominent in noncardiac diagnosis and chest pain NOS than in ACS and non-ACS cardiovascular diagnoses for mortality, and in non-ACS patients than in ACS patients for MACE (hazard ratio for doubling of cTnI 1.85, 2.05, 8.26 and 4.14, respectively; P for interaction 0.011 for mortality; 1.04, 1.23, 1.54 and 1.42, respectively; P for interaction <0.001 for MACE).; In patients presenting to the ED with chest pain, cTnI elevation was associated with a worse prognosis in non-ACS patients than in ACS patients