hsTnT Assay Research Articles

The relative merits of using a high-sensitivity cardiac Troponin T assay compared to a nonhigh-sensitivity troponin T assay after noncardiac surgery

Troponin elevation after noncardiac surgery is associated with an elevated risk of 30-day mortality. Little is known about relative merit of using a high-sensitivity Troponin T (hsTnT), the fifth-generation assay, vs the nonhigh sensitivity Troponin T (non-hsTnT), the fourth-generation assay, in the noncardiac surgery setting. We aimed to identify whether hsTnT can identify additional patients at risk that would have gone undetected with non-hsTnT measurement. The VISION Study included 40,004 noncardiac surgery patients with postoperative troponin measurements. Among them, 1,806 patients had both fourth-generation non-hsTnT and fifth-generation hsTnT concomitant measurements (4,451 paired results). We compared the absolute concentrations, the timing, and the impact of different thresholds on predicting 30-day major cardiovascular complications (composite of death, nonfatal cardiac arrest, coronary revascularization, and congestive heart failure). Based on the manufacturers' threshold of 14 ng/L, 580 (32.1%) patients had postoperative hsTnT concentrations greater than the threshold, while their non-hsTnT concentrations were below the manufacturer's threshold. These 580 patients had higher risk of major cardiovascular events (OR 2.33; CI 95% 1.04-5.23; P = .049) than patients with hsTnT concentrations below the manufacturer threshold. Among patients with myocardial injury after noncardiac surgery, only 50% would be detected by the fourth-generation non-hsTnT assay at 6 to 12 hours postoperative as compared to 85% with the fifth-generation hsTnT assay (P-value < .001). Within the first 3 postoperative days, fifth-generation hsTnT identified at least 1 in 3 patients with troponin elevation that would have gone undetected by fourth-generation non-hsTnT using published thresholds in this setting. Furthermore, fifth-generation hsTnT identified patients with an elevation earlier than fourth-generation non-hsTnT, indicating potential to improve postoperative risk stratification.

Mortality prediction using high-sensitivity troponin after coronary artery bypass surgery

Abstract Introduction Recommendations regarding the threshold levels of cardiac troponin elevations for the definition of peri-operative myocardial infarction and clinically important peri-procedural myocardial injury in patients undergoing cardiac surgery range widely (&amp;gt;10 to ≥70x the upper limit of normal (ULN)) (1,2). Limited evidence is available to support these recommendations. In a recent multicentre cohort study, Devereaux and colleagues (3) characterised appropriate thresholds of high-sensitivity troponin-I (hs-TnI) for defining myocardial injury within 3 days after cardiac surgery. The threshold associated with an increased risk of 30-day mortality after coronary artery bypass grafting (CABG) was 218 xULN (95% confidence interval (CI), 40-318) of the hs-TnI assay. There have been no large studies assessing this threshold using high-sensitivity troponin-T (hs-TnT). Furthermore, the long-term prognostic value of troponin following CABG is unknown. Purpose The aim of our study was to assess the threshold associated with an increased risk of 30-day and 5-year mortality using hs-TnI assays, and to compare these thresholds to those using hs-TnT assays. Methods A retrospective cohort study was carried out using the National Institute for Health Research Health Informatics Collaborative Cardiovascular dataset (4,5) of all consecutive patients who had a troponin measured at five hospitals between 2010 and 2017. Patients who had a troponin measurement within three days following CABG were identified. Results were analysed using multivariable adjusted restricted cubic spline Cox regression. All hazard ratios were adjusted for the following components of the European System for Cardiac Operative Risk Evaluation II (EuroSCORE II); age, gender, renal impairment, poor mobility, chronic lung disease, diabetes, left ventricular function, and pulmonary hypertension. Analyses on troponin were performed using the peak troponin level, which was the highest troponin level measured within the first three days following CABG. All troponin measurements were high-sensitivity and were standardised by using the ratio of the observed troponin value divided by the ULN for each troponin assay. The reference for hazard ratios was a troponin level of 1 xULN. Results A total of 1055 patients (median age 72 years (interquartile range 63 to 78), 79% male) had a troponin measured within three days post-CABG at the five centres between 2010 and 2017. The threshold for hs-TnI associated with an increased mortality risk was 196xULN (95%CI, 42-494) for predicting 30-day mortality (Figure 1A) and 157xULN (95%CI, 32-409) for 5-year mortality (Figure 1B). The thresholds were similar for hs-TnT assays (Figure 1C and 1D). Conclusion The currently recommended troponin thresholds for diagnosing significant myocardial injury following cardiac surgery (&amp;gt;10 to ≥70xULN) are too low. There was good correlation between hs-TnI and hs-TnT measurements for predicting both short- and long-term mortality.Figure 1

Abstract 14946: Sex Differences in Growth Differentiation Factor-15 and Association With Acute Myocardial Infarction and Death at 90 Days in Emergency Department Patients Presenting With Acute Chest Pain and Normal Troponin Levels

Introduction: Growth differentiation factor (GDF)-15, a novel biomarker of cardiac stress, has been recently studied as a tool in predicting cardiovascular outcomes in patients with acute chest pain, when compared against high-sensitivity troponin T (hs-TnT). However, GDF-15 is not approved for cardiac indications in the United States, with limited nationwide data evaluating subpopulations by key demographic and clinical characteristics. Hypothesis: GDF-15 levels demonstrate sex-specific differences and serve as an independent predictor of 90-day acute myocardial infarction (MI) and all-cause death in patients presenting to the emergency department (ED) with acute chest pain and normal hs-TnT levels. Methods: This study was a secondary analysis of the STOP-CP (High Sensitivity Cardiac Troponin T to Optimize Chest Pain Risk Stratification) trial, which prospectively enrolled adults ≥ 21 years presenting to eight EDs in the US with suspected acute MI over a twenty-month period. Blood sampling was performed at presentation, with hs-TnT and GDF-15 assays performed at a central laboratory. The outcomes of interest were the composite of acute MI and all-cause death at 90 days. Multiple logistic regression models were fitted for timepoint with multiple independent variables including the following: age, sex, ischemic electrocardiogram, hs-TnT, GDF-15, and creatinine. Results: We studied 1,428 patients; median age was 58 years and 54% (765) were male. The composite outcome of acute MI or death occurred in 3% (37) at 90 days. In multivariable regression models in patients with baseline normal hs-TnT levels, GDF-15 was associated with acute MI or all-cause death at 90 days (Odds Ratio 1.03, 95% Confidence Interval 1.01-1.05). Median GDF-15 levels were 1266 pg/mL in males (25th percentile-75th percentile, 914-2038 pg/mL), and 1504 pg/mL in females (25th percentile-75th percentile, 987-2197 pg/mL). Conclusions: Among adult ED patients presenting with acute chest pain with normal troponin levels, the novel biomarker GDF-15 was independently associated with 90-day acute MI or death, with higher median GDF-15 levels in females compared to males. These data suggest a role for GDF-15 in short-term cardiac risk stratification.

A-010 Systemwide Implementation of High Sensitivity Troponin T in a Multi-center Hospital Set Up with Instrument Variability: The Baystate Health Experience

Abstract Background High-sensitivity cardiac troponin (hs-cTn) testing helps in rapid risk stratification in patients with acute coronary syndromes resulting in early identification of low-risk patients eligible for early discharge. A high sensitivity troponin test can measure the 99th percentile upper reference limit with an analytical imprecision ≤10% and it can measure cTn above the limit of detection in ≥50% of healthy subjects. We carried out method validation of the Elecsys Gen 5 hsTnT assay with variable instrument capacities like Roche cobas e801, e601, and e411 in our health system. The analytical variability of these instruments was studied and standardized to implement the Gen 5 hsTnT assay systemwide for clinical use in four hospitals. Methods The cTnT control samples with low, medium, and high concentrations were used for precision studies (N = 20). The calibration materials at five levels ranging from 8 ng/L to 10 000 ng/L were used for evaluating linearity, accuracy, and analytical measurement range. The observed and assigned values were compared using linear regression analysis. Heparinized plasma samples were tested using the Gen 5 hsTnT assay. Method comparisons were carried out on different Roche cobas analyzers in each hospital splitting remnant specimens. Analyzer e801 performance was compared with a reference laboratory. Simultaneously, the e601 and e411 analyzers were compared with the e801. Statistical analysis was carried out using EP Evaluator and GraphPad Prism. Results The Roche e801 demonstrated imprecision of 0.5%–2.2% (N = 20), the e601 had imprecision of 0.4%–1.4% (N = 20) and the e411 had 0.8%–4.8% (N = 20) across the three levels of control samples tested. These were well below the expected imprecision criteria of ≤10% for troponins. Deming regression analysis of the 5th GEN assays showed linear relationship across platforms: y (e801 5th GEN) = 1.007x (Reference Lab 5th GEN) + 50.65, R = 0.9899 with positive bias of 8% (N = 45); y (e601 5th GEN) = 0.929x(e801 5th GEN) + (−1.426), R = 0.9995 with negative bias of 7% (N = 48); y (e411 5th GEN) = 0.942x(e801 5th GEN) + (−7.044), R = 1.000 with negative bias of 7% (N = 49). The accuracy, reportable range, and linearity of Gen 5 hsTnT were tested on e801, e611 and e411 analyzers over a measured range of 8–10 000 ng/L. Allowable systematic error (SEa) was 1.5 ng/L (conc) or 5.0% (e801); 1.5 ng/L (conc) or 7.5% (e611 and e411). The maximum deviation for a mean recovery from 100% was 2.4% (e801), 2.7% (e601) and 6.2% (e411). The 5 of 5 mean recoveries were accurate within the SEa for all the three analyzers. The 15 out of 15 results were accurate within the allowable total error (TEa) of 3 ng/L (conc) or 10.0% (e801), 3 ng/L (conc) or 15.0% (e601 and e411). The three analyzers passed reportable range and accuracy tests, and the results were linear. Conclusion The TEa was determined from instrument specific imprecision, systemwide medical decision limits and parameters of rule out criteria. The standardization of analytical performance characteristics is important in a large health system with instrument variability and provision of transfer of care across health systems.

Predictors of Stress-Delta High-Sensitivity Troponin T in Emergency Department Patients Undergoing Stress Testing.

Background and objective Elevations in high-sensitivity troponin T (hs-TnT) are frequently observed following extreme physical exercise. In light of this, we sought to determine whether specific clinical characteristics are associated with this phenomenon in patients undergoing cardiac exercise tolerance testing (ETT). Methods We conducted a retrospective analysis of a prospectively collected biospecimen repository of 257 patients undergoing a stress echocardiogram forpossible acute coronary syndrome (ACS). Ischemic electrocardiogram (ECG) changes during ETT and the presence or absence of ischemia on imaging were determined by a board-licensed cardiologist. N-terminalpro-brain natriuretic peptide (NT-proBNP) and hs-TnT assays were obtained immediately before and two hours following ETT. We developed linear regression models including several clinical characteristics to predict two-hour stress-delta hs-TnT. Variable selection was performed using theleast absolute shrinkage and selection operator (LASSO). Results The mean age of the patients was 52 years [standard deviation (SD): 11.4]; 125 (48.6%) of them were men, and 88 (34.2%) were African-American. Twenty-two patients (8.6%) had ischemia evident on echocardiography, and 31 (12.1%) had ischemic ECG changes during exercise. The mean baseline hs-TnT was 5.6 ng/L (SD: 6.4) and the mean two-hour hs-TnT was 7.1 ng/L (SD: 10.2). Age and ischemic ECG changes were associated with two-hour stress-delta hs-TnT values. Conclusions Based on our findings, ischemic changes in stress ECG and age were associated with an increase in hs-TnT levels following exercise during a stress echo.

High-sensitivity troponin T in preterm infants with a hemodynamically significant patent ductus arteriosus

Background: The incidence of patent ductus arteriosus (PDA) is inversely related to gestational age. Cardiac troponin T (cTnT) is a specific marker for myocardial ischemic injury. The aim of this work was to investigate if a hemodynamically significant patent ductus arteriosus leads to elevated high- sensitivity troponin T (hsTnT) levels in serum. Methods: This prospective observational research included 60 preterm infants &lt;34 weeks’ gestation, weighing &lt;1500 g with PDA. Patients were classified into two groups according to the ECHO findings: Group A: preterm infants who had hs.PDA (PDA &gt;1.5 mm and LA: Ao &gt;1.2 and group B: preterm infants without hs.PDA. All cases were subjected to clinical examination, echocardiogram and hsTnT assay. Results: Serum hsTnT levels was significantly elevated in patients with hs PDA compared to patients without hs PDA. High sensitive T-troponin can significantly detect hsPDA with AUC of 0.986, P value &lt;0.001. At cut off &gt;100 pg/ml, it’s a significant detector with sensitivity of 93.33%, specificity of 90%, PPV of 90.3, NPV of 93.1 and diagnostic accuracy of 91.5%. PDA had a significant positive correlation with hsTnT (r=0.803, P&lt;0.001). Conclusions: HsTnT can significantly detect hemodynamically significant PDA in preterm infants with high sensitivity and specificity.

Troponin T Is Negatively Associated With 3 Tesla Magnetic Resonance Peripheral Nerve Perfusion in Type 2 Diabetes

ObjectiveThe pathogenesis of diabetic polyneuropathy (DN) is poorly understood and given the increasing prevalence of DN, there is a need for clinical or imaging biomarkers that quantify structural and functional nerve damage. While clinical studies have found evidence of an association between elevated levels of troponin T (hsTNT) and N-terminal pro brain natriuretic peptide (proBNP) with microvascular compromise in type 2 diabetes (T2D), their implication in mirroring DN nerve perfusion changes remains unclear. The objective of this study was, therefore, to investigate whether hsTNT and proBNP assays are associated with MRI nerve perfusion in T2D.MethodsIn this prospective cross-sectional single-center case-control study, 56 participants (44 with T2D, 12 healthy control subjects) consented to undergo magnetic resonance neurography (MRN) including dynamic contrast-enhanced (DCE) perfusion imaging of the right leg. Using the extended Tofts model, primary outcome parameters that were quantified are the sciatic nerve’s microvascular permeability (Ktrans), the extravascular extracellular volume fraction (ve), and the plasma volume fraction (vp), as well as hsTNT and proBNP values from serological workup. Further secondary outcomes were clinical, serological, and electrophysiological findings.ResultsIn T2D patients, hsTNT was negatively correlated with Ktrans (r=-0.38; p=0.012) and ve (r=-0.30; p=0.048) but not with vp (r=-0.16; p=0.294). HsTNT, Ktrans, and ve were correlated with peroneal nerve conduction velocities (NCVs; r=-0.44; p=0.006, r=0.42; p=0.008, r=0.39; p=0.014), and tibial NCVs (r=-0.38;p=0.022, r=0.33; p=0.048, r=0.37; p=0.025). No such correlations were found for proBNP.ConclusionsThis study is the first to find that hsTNT is correlated with a decrease of microvascular permeability and a reduced extravascular extracellular volume fraction of nerves in patients with T2D. The results indicate that hsTNT may serve as a potential marker for the assessment of nerve perfusion in future studies on DN.

Emergency Department Management of Chest Pain With a High-Sensitivity Troponin-Enabled 0/1-Hour Rule-Out Algorithm.

The analytical sensitivity of high-sensitivity cardiac troponin T (hsTnT) assays has enabled rapid myocardial infarction rule-out algorithms for emergency department (ED) presentations. Few studies have analyzed the real-world impact of hsTnT algorithms on outcomes and operations. Comparison of ED length of stay (LOS) and 30-day outcomes (return to ED, inpatient admission, and mortality) for patients presenting with chest pain during 2 separate 208-day periods using a 0/1-hour hsTnT-enabled algorithm or fourth-generation TnT. Discharge, 30-day readmission, and 30-day mortality rates were not significantly different with fourth-generation TnT vs hsTnT. Thirty-day return rates were significantly decreased with hsTnT (17.4% vs 14.9%; P < .01). For encounters with TnT measured at least twice and resulting in discharge, median ED LOS decreased by 61 minutes with the use of hsTnT (488 vs 427 minutes; P < .0001). Median time between first and second TnT results decreased by 82 minutes with hsTnT (202 vs 120 minutes; P < .0001), suggesting that the 0/1-hour algorithm was incompletely adopted. Implementation of the hsTnT algorithm was associated with decreased 30-day return rates and decreased ED LOS for a subset of patients, despite incomplete adoption of the 0/1-hour algorithm.

Abstract 14266: Outcomes of Chest Pain Patients Following Application of a Validated High Sensitivity Troponin Algorithm: Comparison of 30 Day Death/ MI of Algorithm Concordant vs Discordant Discharges

Introduction: High sensitivity troponin (hsTn) assays effectively risk stratify patients with chest pain when a validated serial algorithm is utilized. Most of these algorithms require multiple draws for initial values in an intermediate range below a cutoff considered unequivocally consistent with MI. Little is known regarding outcomes of patients who are discharged following deviation from these algorithms. Hypothesis: Minor deviation from a validated hsTn algorithm may yield unacceptable outcomes in chest pain patients. Methods: Retrospective review of outcomes in patients presenting with chest pain to Geisinger Health System emergency departments and discharged based on application of a validated 0/1/3 hour hsTroponinT (hsTnT) algorithm over a 2-year period. We compared 30-day death/MI in patients who had hsTnT results that were consistent with “ruling out” (algorithm concordant) vs those who were discharged despite either equivocal hsTnT results or incomplete application of the algorithm (algorithm discordant). Patients who were admitted or met criteria for MI based on a peak hsTnT &gt; 52ng/L were excluded. Results: Out of 10,342 patients discharged after hsTnT algorithm, 1,166 (11.3%) were algorithm-discordant. Thirty-day death/MI occurred in 13 (0.14%) of patients managed protocol concordant and 16 (1.37%)of patients managed protocol discordant (p&lt;0.001). The 16 discordant pts with death/MI were algorithm-discordant due to either having only a single hsTnT draw (12) or a 0-1hr delta &gt; 5ng/L (4). Comparing all patients with vs without 30day death/MI, univariate predictors included median age (66 vs 50yr, p&lt;0.0001), prior CAD history (41.4 vs 17.5%, p=0.002), hyperlipidemia (44.8 vs 21.8%, p=0.006) and hsTnT algorithm discordance (55.2 vs 11.1%, p&lt;0.001). A multivariable logistic regression model found that among univariate predictors only algorithm discordance was an independent predictor of 30-day death/MI (OR 6.42, p&lt;0.001). Conclusions: Deviation from an hsTnT algorithm was associated significantly with increased 30 day cardiac events. This study highlights the importance of maintaining concordance with algorithm details when using hsTnT assays to triage chest pain patients.

Predictors of unfavourable outcome in clinically stable, low risk acute pulmonary embolism patients (sPESI 0)

Abstract Introduction Nowadays one of the most challenging tasks is to identify, within the large group of normotensive and clinically stable acute pulmonary embolism (APE) patients, those who are at “sufficiently low” risk to permit early discharge and home treatment. Current ESC guidelines suggest, that troponin measurement is optional in sPESI 0 patients. Aim The aim of this study was to assess whether right ventricular dysfunction (RVD) in transthoracic echocardiographic examination (TTE) and/or elevated plasma troponin level improves in-hospital risk stratification in sPESI 0 patients. Methods Post-hoc analysis of a prospective study of 1191 patients with at least segmental APE confirmed in computed tomography (CT). Among this group 434 patients (208 F, age median = 52 yrs [39; 67]) were classified to low risk group according to sPESI. TTE and TnT concentration were assessed within the first 24-hours from admission. Echocardiographic criteria for RVD were RV/LV ratio≥1 or tricuspid regurgitant pressure gradient ≥31 mmHg. The sPESI score was calculated from patient records. The combined endpoint (CE) included in-hospital death of any cause and/or haemodynamic deterioration requiring catecholamines i.v., rescue thrombolysis, cardio-pulmonary resuscitation, cardiac surgical intervention or percutaneous catheter-directed treatment. Results Among 434 sPESI 0 patients, cardiac troponin plasma level was assessed in 409 individuals, 136 results were above the normal limit. CE occurred in 6 patients with elevated and 0 with non-elevated troponin concentration (p=0,0013). In 253 cases high-sensitive troponin (hsTnT) assays were used. Median hsTnT concentration was significantly higher in patients with CE (0,032 ng/ml [0,024; 0,127] vs 0,09 ng/ml [0; 0,025]) SPESI and hsTnT assessment showed AUC ROC=0.834 (0.727–0,941; p=0.000) for the CE with suggested threshold 0,024 ng/ml (Fig. 1). Interestingly, no statistically significant differences in RV/LV ratio or TRPG between CE and non-CE group were observed. Furthermore, CE did not occur more often in patients with RVD (7 vs 1; p=0,067). Conclusion SPESI combined with normal cardiac troponin plasma concentration may be used for predicting favourable outcome in patients with APE and thus select candidates for home treatment. We suggest to assess plasma troponin levels in all normotensive patients early, before discharge to home treatment. However, due to relatively low number of endpoints, these findings need to be confirmed in further studies enrolling more patients. Funding Acknowledgement Type of funding sources: None. Figure 1. hsTnT ROC

Comparison of Perioperative High-Sensitive Troponin T and Troponin I Assays in Cardiac Surgery

Troponin measurements are among the standard parameters for monitoring perioperative myocardial ischaemia after cardiosurgical procedures. As high-sensitive assays continue to replace older analytic parameters with lower sensitivity, this study aimed to compare perioperative profiles of a high-sensitive troponin T assay (hsTnT, Roche Diagnostics, Mannheim, Germany) with a troponin I assay (sTnI, Siemens Healthcare Diagnostics, Eschborn, Germany). A total of 287 consecutive patients undergoing a typical spectrum of cardiac procedures from August 2017 to March 2018 monitored with the hsTnT assay were compared with a propensity-matched collective analysed with the sTnI assay. For side-by side comparison, the peak troponin (Tmax) values were scaled to a z-score distribution before comparison. Despite absolute postoperative hsTnT and sTnI values differing by an order of magnitude, parameters could be scaled to a common distribution with kernel density curves overlapping 92%. Both parameters showed equal behaviour in subgroup analyses regarding relevant perioperative factors, such as type of procedure, cross-clamping time, and type of cardioplegic solution. However, there were some differences regarding pre-existing renal impairment between both parameters. In both groups, renal failure patients with chronic kidney disease stages IV or V as well as patients on haemodialysis exhibited a marked Tmax increase of >100% compared with normal kidney function (hsTnT,+121%; 2,383.5 vs 1,078.8 ng/L; p=0.0006; and sTnI,+149%; 27.3 ng/mL vs 11.0 ng/mL; p=0.009). However, in patients with moderately impaired renal function, those in the hsTnT group, but not in the sTnI cohort, showed significantly increased Tmax values (CKD stages II or III, 1,233.5 ng/L [+14%] and 1,314.1 ng/L [+22%] vs 1,078.8 ng/L; p=0.01 and p=0.03). In these patients, the postoperative interval until Tmax was reached was also significantly increased (14.4 and 19.0 hrs vs 12.4 hrs for chronic kidney disease stages II and III; p=0.0038 and p<0.001), indicating a higher rate of accumulation in the hsTnT parameter. In the context of cardiac surgery, this study found that both parameters behaved in a similar manner under most relevant circumstances. Despite significant difference in the absolute serum concentration, hsTnT and sTnI can be scaled to virtually identical distributions. However, renal impairment did affect both parameters differently with troponin T but not troponin I, showing evidence of accumulation in moderately impaired renal disease.

The change in high-sensitivity troponin-T as a risk factor for significant coronary stenosis in patients with acute coronary syndrome.

Background/AimsHigh-sensitivity cardiac troponin (hs-TnT) assays detect very low levels of cardiac troponin. This study examined the interval change between initial and subsequent hs-TnT levels and evaluated its ability to predict significant coronary stenosis.MethodsThe study analyzed 163 patients who presented with acute coronary syndrome (ACS) and underwent coronary angiography (CAG) between April 2014 and May 2018. The 0 and 3-hour hs-TnT were checked. The patients were subdivided into positive (n = 32) and negative (n = 131) interval change groups. The presence of significant coronary artery stenosis on CAG in the two groups was compared.ResultsThe positive interval change group was older and had higher 0 and 3-hour hs-TnT and blood glucose levels than the negative interval change group. Significant coronary stenosis was more common in the positive interval change group than in the negative interval change group (68.8% vs. 23.7%, p = 0.001). However, vasospasm was more common in the negative interval change group (6.3% vs. 31.3%, p = 0.003). The positive interval change group had higher rates of bifurcation lesions and received more percutaneous coronary intervention. In multivariate analysis, age, interval change of serial hs-TnT and diabetes mellitus were independent predictors of significant coronary artery stenosis.ConclusionsThis study identified a relationship between the serial change in cardiac biomarkers and the presence of significant coronary stenosis in patients with ACS. Serial hs-TnT change was associated with real angiographic stenosis in patients with ACS.

Diagnostic Performance of Point-of-Care Troponin I and Laboratory Troponin T in Patients Presenting to the ED with Chest Pain: A Comparative Study.

BackgroundChest pain is a common symptom in patients visiting the emergency department (ED). Diagnosing acute coronary syndrome is a challenging task for emergency physicians. Evaluation of chest pain depends on clinical symptoms and signs, ECG, and cardiac enzymes. Here, we aimed to compare the diagnostic performance of the point-of-care troponin I assay with laboratory HsTnT assay in patients presenting to the ED with chest pain.MethodsA prospective study was done at the ED of Alkhor Hospital, Hamad Medical Corporation, between March 2016 and December 2016. Patients more than 18 years old who presented to the ED with chest pain were enrolled. Patients with renal failure, initial ECG showing ST-elevation MI, or arrhythmias, and hemodynamically unstable patients were excluded. A blood sample was collected at 0 and 3 hours post-admission for POC TnI and laboratory HsTnT assay. The sensitivity, specificity, PPV, NPV, and AUC were determined and compared.ResultsOut of 313 patients enrolled, ten were excluded. At 0 hour, the POC TnI assay had a lower sensitivity (72.5% versus 97.5%) and had almost equal specificity (99.24% versus 93.2%) when compared to lab HsTnT assay. At 3 hours post-admission, the sensitivity increased to 95% versus 100%, and specificity was 100% versus 94.3% when compared to lab HsTnT. The POC TnI assay had a higher PPV than HsTnT, whereas both assays showed a high NPV at 0 and 3 hours.ConclusionAlthough the diagnostic performance of POC TnI was lower than that of Lab HsTnT at 0 hour, at 3 hours post-admission, the diagnostic performance was almost equal to that of HsTnT. Hence we conclude that chest pain in patients with a negative POC TnI at 3 hours post-admission is unlikely to be due to NSTEMI.

Abstract 387: Practice Patterns and Use of High Sensitivity Troponin Assays in the Outpatient Setting

Introduction: High sensitivity troponin T (hs-TnT) are more sensitive than prior assays to evaluate patients for acute coronary syndrome. To date, hs-TnT utilization in the outpatient setting is not well described. Methods: We identified outpatient hs-TnT tests ordered at a large medical center in the first 9 months of implementation (April-December 2018). Charts were reviewed by physicians to identify patient characteristics, specialty of ordering provider, reason for ordering hs-TnT, and clinical action taken. Using unadjusted two-sample t-tests, we compared the proportion of patients referred to the ED between patients with hs-TnT levels ≥99 th % sex-specific cutoffs (≥15 ng/dL men, ≥10 ng/dL women) versus those with either undetectable hs-TnT or detectable &lt;99 th % (control group). Results: About 100 hs-TnT outpatient tests were ordered. Patients had mean age of 66 years, 53% were male; 30% had coronary artery disease, and 12% had left ventricular ejection fraction ≤40%. Most orders were placed by cardiologists (n=58) followed by primary care physicians (n=30). The top chief complaints were dyspnea (n=38) and chest pain (n=33). Of all hs-TnT samples, 27% were undetectable, while mean detectable hs-TnT level was 38.8 ng/L, of which 57% were ≥99 th %. About 25% of patients had chronic cardiovascular conditions (like heart failure) but were asymptomatic at the time of the test. Among symptomatic patients (n=75), 31% were sent home, 28% to stress test, and 16% to the ED. Patients with hs-TnT ≥99 th % were 4.6 times more likely (95% CI 1.1-19.5, p=0.04) to be referred to the ED, compared to control. Conclusions: This is the first study describing outpatient utilization of the novel hs-TnT assay in the U.S. Despite the lack of consensus on diagnosing cardiac ischemia in outpatient clinics, providers are ordering hs-TnT in this setting - and hs-TnT values seem to influence their decision to triage patients to the ED. Our results highlight the need to standardize the implementation of hs-TnT for outpatient evaluation of cardiac ischemia. Providers are also collecting hs-TnT among asymptomatic patients with heart disease unrelated to ischemia. This suggests that novel uses of hs-TnT may emerge to monitor and prognosticate chronic cardiovascular conditions. Figure. Patient Triage based on Elevation in Outpatient hs-TnT Level

Biotin interference: evaluation of a new generation of electrochemiluminescent immunoassays for high-sensitive troponin T and thyroid-stimulating hormone testing

Background Biotin is currently a matter of concern for laboratories using biotin-streptavidin-based immunoassays. Biotin interferences have been reported for high-sensitive troponin T (hsTnT) and thyroid-stimulating hormone (TSH) assays. We aimed to evaluate the new generation of hsTnT and TSH electrochemiluminescent immunoassays announced to be less sensitive to biotin. Methods Firstly, we assessed the analytical performances of new generation assays (imprecision, bias, total error, limit of quantification) and compared previous and new generation assays in the absence of biotin. Secondly, we challenged both generations of assays with samples spiked with seven different biotin levels. The efficiency of new generation assays was also compared to the streptavidin beads treatment. Results New generation assays presented suitable analytical performances. Previous and new generations of hsTnT and TSH assays were commutable in the absence of biotin. In the presence of biotin, we confirmed that previous generation assays were affected by biotin concentration as low as 40.5 ng/mL and that new generation assays were not affected up to the announced tolerance threshold of 1200 ng/mL. After the streptavidin beads treatment, we observed a higher imprecision for both parameters and a constant 10% negative bias for TSH compared to new generation assays. Conclusions New generation of electrochemiluminescent immunoassays appears as a reliable systematic solution to prevent biotin interference for hsTnT and TSH testing.

High-Sensitivity Troponin T Testing: Consequences on Daily Clinical Practice and Effects on Diagnosis of Myocardial Infarction.

It remains unclear how introduction of high-sensitivity troponin T testing, as opposed to conventional troponin testing, has affected the diagnosis of acute myocardial infarction (AMI) and resource utilization in unselected hospitalized patients. In this retrospective analysis, we include all consecutive cases from our center during two corresponding time frames (10/2016–04/2017 and 10/2017–04/2018) for which different troponin tests were performed: conventional troponin I (cTnI) and high-sensitivity troponin T (hs-TnT) assays. Testing was performed in 18,025 cases. The incidence of troponin levels above the 99th percentile was significantly higher in cases tested using hs-TnT. This was not associated with increased utilization of echocardiography, coronary angiography, or percutaneous coronary intervention. Although there were no changes in local standard operating procedures, study site personnel, or national coding guidelines, the number of coded AMI significantly decreased after introduction of hs-TnT. In this single-center retrospective study comprising 18,025 mixed medical and surgical cases with troponin testing, the introduction of hs-TnT was not associated with changes in resource utilization among the general cohort, but instead, led to a decrease in the international classification of diseases (ICD)-10 coded diagnosis of AMI.

Emergency Department Clinician Perceptions of Implementing High-Sensitivity Troponin T Assay in an Academic Hospital Emergency Department

PurposeA newly approved, high-sensitivity troponin T (hsTnT) assay may offer opportunities to more rapidly assess for acute coronary syndrome and identify lower thresholds of myocardial injury. As more emergency departments begin to use the hsTnT assay, anticipating barriers to hsTnT implementation success are critical to realizing potential benefits in rapid, accurate patient assessment. MethodsAt a tertiary health system emergency department, hsTnT was implemented along with a diagnostic algorithm and a decision tree to aid in utilization. Qualitative interviews with 18 physicians and advance practice providers were conducted 2 months’ postimplementation and again 4 to 6 months postimplementation to capture clinician perceptions to hsTnT implementation efforts. Deductive coding was performed using implementation science determinants frameworks to identify emerging themes related to this topic. ResultsFour themes emerged from the interviews: 1) the need for additional clinician education, 2) challenges with care handoffs, 3) lack of buy-in from the hospital community, and 4) key successes. ConclusionInterviews demonstrated that implementation of hsTnT was associated with several implementation barriers from the perspective of emergency department clinicians. Future implementation efforts should focus on diverse and sustained staff educational efforts, models that address challenges with care handoffs between emergency department clinicians and inpatient clinicians, and operational teams that include inpatient clinicians to facilitate buy-in.

ASSESSING PROVIDER ATTITUDES OF IMPLEMENTING INPATIENT HIGH SENSITIVITY TROPONIN ASSAY

In May 2019, Michigan Medicine launched a new high-sensitivity troponin T (hsTnT) assay for inpatient utilization. Although widely used and studied internationally, the utilization of inpatient hsTnT in the United States is less ubiquitous and its implications on medical decision-making are less

FIFTH GENERATION TROPONIN ASSAY IS SUBJECT TO ANTIBODY INTERFERENCE: FIRST REPORTED CASE

Both the 5th generation, or high-sensitivity, Troponin T (hs-TnT) and 4th generation Troponin T (4G-TnT) assays are electrochemiluminescent immunoassays. The hs-TnT assay utilizes a chimeric mouse-human antibody whereas the 4G-TnT assay is solely murine. Thus, heterophilic antibody interference to

The Asia-Pacific Society of Cardiology (APSC) Expert Committee Consensus Recommendations for Assessment of Suspected Acute Coronary Syndrome Using High-Sensitivity Cardiac Troponin T in the Emergency Department.

The Asia-Pacific Society of Cardiology (APSC) high-sensitivity troponin T (hs-TnT) consensus recommendations and rapid algorithm were developed to provide guidance for healthcare professionals in the Asia-Pacific region on assessing patients with suspected acute coronary syndrome (ACS) using a hs-TnT assay. Experts from Asia-Pacific convened in 2 meetings to develop evidence-based consensus recommendations and an algorithm for appropriate use of the hs-TnT assay. The Expert Committee defined a cardiac troponin assay as a high-sensitivity assay if the total imprecision is ≤10% at the 99th percentile of the upper reference limit and measurable concentrations below the 99th percentile are attainable with an assay at a concentration value above the assay's limit of detection for at least 50% of healthy individuals. Recommendations for single-measurement rule-out/rule-in cutoff values, as well as for serial measurements, were also developed. The Expert Committee also adopted similar hs-TnT cutoff values for men and women, recommended serial hs-TnT measurements for special populations, and provided guidance on the use of point-of-care troponin T devices in individuals suspected of ACS. These recommendations should be used in conjunction with all available clinical evidence when making the diagnosis of ACS.