Diagnostic Accuracy of a Novel 0/1-H Algorithm Using Point-of-Care High-Sensitivity Troponin in the Emergency Department.

Patients presenting to the emergency department with chest pain are routinely risk stratified for major adverse cardiac events using the HEART (History, Electrocardiogram, Age, Risk factors, and Troponin) score pathway, which incorporates clinical features, risk factors, electrocardiography findings, and initial serum troponin testing. A new HEART pathway incorporating high-sensitivity troponin level may improve risk stratification among patients with possible acute myocardial infarction (AMI). To compare health outcomes and resource use among emergency department patients undergoing cardiac risk stratification with a HEART pathway using conventional vs high-sensitivity serum troponin. This multicenter pre-post cohort study was conducted between January 1 and September 6, 2021, at 16 Kaiser Permanente Southern California hospitals during uptake of a high-sensitivity serum troponin assay and included 17 384 adult patients who presented to an emergency department with chest pain and were risk stratified with a HEART pathway based on conventional troponin or high-sensitivity troponin. A HEART pathway incorporating either conventional or high-sensitivity serum troponin was used to stratify study groups for risk of major adverse cardiac events within 30 days. The primary outcome was detection of AMI in the emergency department and within 30 days. Of the 17 384 patients (median age, 58 years [IQR, 45-69 years]; 9767 women [56.2%]), 12 440 (71.6%) were risk stratified with a HEART pathway based on conventional troponin, and 4944 (28.4%) were risk stratified with a HEART pathway based on high-sensitivity troponin. Detection of AMI within 30 days was higher for the high-sensitivity troponin group than the conventional troponin group (288 [5.8%] vs 545 [4.4%]; P < .001), while the 30-day all-cause mortality rate was unchanged (16 [0.3%] vs 50 [0.4%]; P = .50). In the emergency department, 228 of 4944 patients (4.6%) in the high-sensitivity troponin group received a diagnosis of AMI compared with 251 of 12 440 patients (2.0%) in the conventional troponin group (P < .001). Among those who did not receive a diagnosis of AMI in the emergency department, an additional 60 patients (1.2%) in the high-sensitivity troponin group and 294 (2.4%) in the conventional troponin group (P < .001) received a diagnosis within 30 days. Patients in the high-sensitivity troponin group had lower rates of health care use compared with the conventional troponin group, including admission (605 [12.2%] vs 1862 [15.0%]; P < .001), stress testing within 7 days (506 [10.2%] vs 1591 [12.8%]; P < .001), and coronary revascularization within 30 days (51 [1.0%] vs 244 [2.0%]; P < .001). This multicenter pre-post cohort study suggests that a new HEART pathway incorporating high-sensitivity troponin may improve detection of AMI and decrease resource use among emergency department patients with chest pain.

How Low Can We Go? The High-Sensitivity Cardiac Troponin Debate

Biomarkers in the triage of chest pain: are we making progress?

The European Cardiac Society have recommended high-sensitivity cardiac troponin testing can be used as part of a “rule-out” strategy for patients with suspected acute coronary syndrome. NICE have recommended the...

AimsThe aim of this study was determine the incidence of major adverse cardiac events within 30 and 365-days among patients discharged from emergency departments (EDs), following a single high-sensitivity cardiac troponin I test result below or close to the limits of detection (LoD).Methods and resultsPatients ≥20 years old who presented to four EDs from mid-2014 to end-2015, underwent a single high-sensitivity troponin test and were discharged were included. Data from ED presentations, hospital admissions, mortality records, and pathology laboratories were linked and harmonized. High-sensitivity troponin levels were categorized as below (<2 ng/L) or close to (<5 ng/L) the LoD. The primary outcome was cardiovascular death and myocardial infarction (MI), identified using ICD-10-AM codes. In a cohort of 6633 patients, 49% had high-sensitivity troponin levels below the LoD (<2 ng/L), and 79% had levels <5 ng/L. There were no primary outcome events at 30-day follow-up among patients with high-sensitivity troponin results below 2 or 5 ng/L. At 365-days, there were 5 (0.15%) and 11 (0.21%) primary outcome events for patients with high-sensitivity troponin results below 2 and 5 ng/L, indicating negative predictive values of 99.85% and 99.79%.ConclusionThese findings confirm that patients with a single very low level of high-sensitivity troponin on presentation to EDs are at low risk of MI and cardiovascular death at 30 and 365 days, supporting the safety of a triage strategy incorporating a single high-sensitivity troponin result below the LoD to identify patients at low-risk, who may be suitable for expedited discharge.

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. 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. 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%). 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.

Low concentrations of high-sensitivity cardiac troponin I determined on presentation to the emergency department (ED) have been shown to have an excellent negative predictive value (NPV) for the identification of acute myocardial infarction. The sensitivity, and therefore clinical applicability, of such testing strategies is unknown. To determine the diagnostic performance of low concentrations of high-sensitivity cardiac troponin I in patients with suspected cardiac chest pain and an electrocardiogram showing no ischemia as an indicator of acute myocardial infarction. A pooled analysis of 5 international (Australia, New Zealand, and England) prospective, observational cohort studies with blinded outcome assessment and 30-day follow-up was conducted. A total of 3155 patients presenting with symptoms suggestive of cardiac ischemia were included in the analysis. Eligible patients had a nonischemic electrocardiogram determined and high-sensitivity troponin I measured at presentation. The lower limit of detection (1.2 ng/L) as well as cutoff concentrations rounded to the nearest integer for a high-sensitivity troponin I assay were used in the analysis. Recruitment was undertaken from November 1, 2007, to August 10, 2013. The primary outcome was fatal or nonfatal acute myocardial infarction occurring within 30 days of ED presentation, adjudicated with serial troponin testing. The secondary outcome was the proportion of patients potentially suitable for early discharge at each cutoff concentration. Of the 3155 eligible patients, 1771 were male (56.1%), and mean (SD) age was 57.4 (13.3) years. Acute myocardial infarction developed in 291 individuals (9.2%). The 1.2-ng/L limit of detection gave a sensitivity of 99.0% (95% CI, 96.8%-99.7%) and an NPV of 99.5% (95% CI, 98.4%-99.9%). This cutoff level would allow for early discharge of 594 patients (18.8%). All higher rounded cutoff values had sensitivities less than 98.0%. Diagnostic performance of the limit of detection was maintained when patients were stratified by age, sex, risk factors, presence of coronary artery disease, and early presentation. High-sensitivity troponin I concentrations determined at presentation to the ED that were below the limit of detection identified 18.8% of patients potentially suitable for discharge, with a high sensitivity for acute myocardial infarction. Rounded cutoff values above the limit of detection may not have the required sensitivity for clinical implementation.

High-sensitivity troponin (Hs-trop) protocols have been developed for the cardiac evaluation of chest pain patients presenting to emergency departments (ED), but uptake has been suboptimal. This retrospective study sought to evaluate the effects of an Hs-trop protocol (Roche Gen-5 troponin assay) implementation on patient outcomes, healthcare utilization, and costs. Patients presenting to EDs with chest pain following implementation of an Hs-trop protocol (POST) were compared to control patients presenting in the year prior (PRE). Study endpoints included troponin elevations, cardiac diagnostic testing, and ED disposition. Among patients discharged directly from the ED, 30- and 90-day death, new myocardial infarction (MI), ED returns, and hospital admissions were compared. In a subset with insurance data, post-discharge healthcare costs and utilization were compared. Among 15 015 patients meeting study criteria, there were no differences in MI diagnoses POST versus PRE, but myocardial injury without MI was more frequent POST (aOR = 9.03; 95% CI: 7.44, 10.96). Noninvasive cardiac testing at the index ED encounter was less frequent POST (aOR = 0.72; 0.67, 0.78), with no difference for invasive angiography. Among patients directly discharged from the ED, no differences were observed for death, but POST patients had fewer ED returns (aOR = 0.70; 0.59, 0.83) and hospital admissions (aOR = 0.62; 0.45, 0.85) within 30 days. Overall healthcare utilization was 8.4% lower in the POST group (p < 0.001) but costs were not different. Following implementation of an Hs-trop protocol, decreases were observed in noninvasive cardiac testing, and ED returns and hospital admissions within 90 days of discharge, without compromising outcomes. Overall healthcare utilization declined.

Objective: This comparative study aims to evaluate the diagnostic performance of the high-sensitive cardiac Troponin T (hs-cTnT) assay in comparison with the previous generation cardiac Troponin I (cTnI). Material and Methods: The study was conducted at Indus Hospital and Health Network's campuses between March and May 2023. Data sourced from electronic medical record system included individuals presenting to the Emergency Department (ED) with suspected Acute Myocardial Infarction (AMI). Both 4th and 5th-generation troponin assays were performed simultaneously for all participants. Statistical analyses were employed to assess the performance of each troponin assay. Results: Out of 354 patients, 205 were diagnosed with AMI. The use of the 5th-generation troponin assay resulted in a 37.9% increase in AMI diagnoses compared to the 4th-generation assay. Performance characteristics indicated that hs-Trop T exhibited significantly higher sensitivity at 99.02% than Trop I at 33.33%. Whereas, the specificity was similar for both the assays. Conclusion: This study highlights that the 5th generation assay, not only revealed a notable increase in AMI diagnoses compared to its predecessor but also underscored the extent of difference in sensitivity between both assays. This discovery carries broader implications for refining diagnostic strategies in the realm of AMI, emphasizing the need for continued exploration and validation in clinical contexts. Keywords: Myocardial infarction, Troponin assay, High sensitive troponin, Diagnostic performance study, Acute coronary syndrome

36 Concomitant Measurement of Copeptin and High Sensitivity Troponin for Fast and Reliable Rule Out of Acute Myocardial Infarction

Diagnosing myocardial infarction: a highly sensitive issue

Single test rule-out of acute myocardial infarction using the limit of detection of a new high-sensitivity troponin I assay

Timely detection of myocardial injury is essential for appropriate management of patients in emergency department (ED) evaluated for acute myocardial infarction. A novel electrocardiogram (ECG) metric, the Cardiac Electrical Biomarker (CEB), uses eigenvalue modeling of the 12-lead ECG and quantifies dipolar vs. multipolar forces. The goal of this project was to study association between the CEB and high-sensitivity troponin I (HsTnI). We conducted a retrospective study of patients, evaluated in the ED for acute myocardial infarction [n = 411; 57.6 ± 13.2 years; 186 (45%) men; 266 (64%) African-Americans]. Resting 12-lead ECG and HsTnI were measured at presentation and at 3, 6, and 9 hours after the initial measurement. The CEB was measured by the VectraplexECG System (VectraCor, Totowa, NJ). Patient-specific longitudinal analysis was performed to study association between the CEB with HsTnI changes over time. The CEB indicated myocardial injury in 116 (28.2%) study participants. HsTnI was significantly elevated during ED observation period in patients with myocardial injury, diagnosed by the CEB [median (interquartile range), 10.3 (5.2-31.4) vs. 6.3 (3.5-16.5) ng/L; P = 0.002]. In a mixed-effects linear regression adjusted for age, race, and sex, increasing HsTnI was associated with the CEB elevation [β-coefficient, 0.071 (95% confidence interval, 0.008-0.134); P = 0.027]. In conclusion, in patients in ED evaluated for acute myocardial injury, increasing values of HsTnI were associated with increasing values of the CEB, suggesting that myocardial injury is the mechanism that underlines acute changes in the CEB.

Combining presentation high-sensitivity cardiac troponin I and glucose measurements to rule-out an acute myocardial infarction in patients presenting to emergency department with chest pain

Background High-sensitivity cardiac troponins (hs-cTn) are key clinical biomarkers in patients presenting with suspected acute coronary syndromes (ACS) to Emergency Departments (EDs). They have facilitated rapid 0h/1h troponin testing protocols, leading to safe, effective, and efficient triage of patients. However, early distinction of myocardial infarction (MI), which has a reported frequency of less than 10% in most cohorts, from the apparently stable hs-cTn elevations of chronic myocardial injury (CMI) remains a challenge. Often CMI patients require confirmation by further testing and observation, prolonging patient length of stay. Further, reliably obtaining serial hs-cTn samples at 60-minutes in a busy ED setting may be difficult. A potential explanation for only 5-6% of Australian sites adopting 0h/1h hs-cTn testing. Methods and Results We undertook a case-control study between March and August 2023 among patients with suspected ACS presenting to Liverpool Hospital ED (Sydney, Australia). 185 patients (cases) underwent hs-cTnT sampling at 30- and 60-minutes (± 5 minutes) after baseline. Diagnosis of MI was made in 8.6%, 35.7% were placed into a further observation group and MI ruled-out in 55.7%. The latter two groups were matched to 169 patients (controls) who received ‘usual’ care, which was a 0h/1h hs-cTnT testing protocol. The case and control arms were matched by age, gender, time from symptom onset and main presenting symptom. Control patients had a median sampling interval of 118 [85 to 174] minutes, rather 60 minutes as the protocol directs. When comparing the paired differences between the case and control arms, there was a mean reduction in length of stay of 104 (95% CI: 41 to 186, P = 0.01) and 47 (95% CI: 11 to 84, P = 0.01) minutes, for the observation and rule-out MI groups respectively. The figure shows the distribution of lengths of stay by group. Among the rule-out group, Wilcoxon signed rank test indicated the control arm had a longer median length of stay of 6.3 [5.1 to 8.4] hours, compared to 5.0 [4.5 to 7.1] hours in the case arm (P=0.005). Similarly, in the further observation group, control patients also had a longer median length of stay of 9.2 [6.9 to 10.4] hours compared to case patients of 8.1 [5.1 to 10.3] hours (P = 0.009). At 30-days, ED representation rates were 10.7% in controls and 8.3% in cases, rehospitalisation 3.6% in controls and 5.3% in cases, cardiac death 0% in both arms and non-cardiac death 1% in both arms. There were no differences in event rates between each arm (P &amp;gt; 0.05). Conclusion Accurate 0h/1h hs-cTnT testing reduces patient length of stay in ED and offers more personalised prediction of MI risk. The importance of adherence to protocol-directed sampling times is clear, where further studies are required regarding routine implementation in a busy ED setting.Exact 60 min TnT and LOSOutcomes at 30 days