deFilippi, Christopher R.

Most patients with chest pain do not have acute myocardial infarction (AMI), yet post-AMI rule-out disposition remains variable. Detectable but sub-99th percentile high-sensitivity cardiac troponin I (hs-cTnI) provides additional prognostic information. We evaluated the economic value of hs-cTnI-guided hospitalizations among non-AMI patients. We analyzed 1481 non-AMI chest pain visits with detectable baseline hs-cTnI across 29 U.S. emergency departments (2014–2016) in the prospective HIGH-US trial using the Atellica IM TnIH assay(Siemens Healthcare Diagnostics, Tarrytown, NY, US). We compared observed standard-of-care admissions with modeled pathways incorporating hs-cTnI thresholds and risk scores, assessing admission rates, costs, and diagnostic accuracy for 30-day death/MI. Overall, 1.0% (n = 15/1481) experienced 30-day death/MI. Standard-of-care admitted 59% of patients with 93% sensitivity and 41% specificity. The modeled pathway using hs-cTnI ≥ 5 ng/L plus non-low risk scores was associated with reduced projected admission of 41%, higher specificity of 60%, and the same 93% sensitivity. Estimated per-patient diagnostic costs were lower under Scenario 1 (noninvasive diagnostic testing only; $1025 vs. $1139) and under Scenario 2 (including inpatient/invasive procedures; $2672 vs. $3536). In subgroups, higher hs-cTnI thresholds conferred further economic benefit without compromising sensitivity. Incorporating sub-99th percentile hs-cTnI thresholds alongside risk scores may support more efficient resource use while maintaining safety, although findings require prospective validation.

Abstract Background High-sensitivity cardiac troponin (hs-cTn) assays are recommended for the diagnosis of acute myocardial infarction. Here, we characterize the analytical performance of a next-generation hs-cTn assay, Elecsys® Troponin T hs Gen 6 (Roche Diagnostics International). Methods Surplus lithium-heparin plasma or serum samples from patients or healthy volunteers were run on Cobas® e 801, e 402, and Pro analyzers. Limits of blank (LoB), limits of detection (LoD), and limits of quantitation (LoQ) were determined according to CLSI EP17-A2, with target values of 1.0 and 1.5 ng/L for LoB/LoD and 3.0 ng/L (10% CV) and 1.5 ng/L (20% CV) for LoQ, respectively. Precision was measured, per CLSI EP17-A2, using 3 QC samples (approximately 4, 30, and 220 ng/L), 12 native samples, and 3 reagent lots. Linearity, per CLSI EP06-Ed2, was determined by diluting samples with cardiac troponin T (cTnT) concentration above the measuring range with a low/blank sample. Interference (per Glick) with endogenous and assay components at 5 cTnT concentrations was assessed. Results Measured values for LoB, LoD, and LoQ at 10% and 20% CV were 0.1 to 0.7 ng/L, 0.3 to 1.4 ng/L, 1.0 to 2.9 ng/L, and 0.4 to 1.2 ng/L, respectively. Repeatability CVs were 1.0 to 5.8% for mean cTnT concentrations of 2.6 to 9230 ng/L in lithium-heparin plasma. High precision was shown across lots, and linearity was observed across the measuring range (1.5 to 9500 ng/L, all Pearson's r = 1.00). No interferences were observed, specified up to ≤1000 mg/dL hemoglobin, ≤50 mg/dL [≤855 µmol/L] icterus/bilirubin, and ≤1200 ng/mL biotin. Conclusions The analytical performance characterization of the assay demonstrated high sensitivity, high precision at the low end and across the measuring range, and resistance to interference.

Abstract Background Measurement of cardiac troponin (cTn) using high-sensitivity assays is recommended for the diagnosis of myocardial infarction. We determined sex-specific and uniform 99th percentile upper reference limits (URLs) using the new Elecsys® Troponin T high-sensitivity Gen 6 assay in a global, healthy reference range cohort. Methods Lithium-heparin plasma and serum samples were prospectively collected from apparently healthy individuals aged ≥20 years across 34 global sites in the United States, Europe, China, and Japan. cTnT was measured using the Troponin T high-sensitivity Gen 6 assay on the Cobas® e 801 analyzer. Exclusion criteria were defined according to the 2022 IFCC guidance. Uniform and sex-specific 99th percentile URLs and nonparametric 95% CIs were determined in plasma and serum separately and combined. Results The final study population comprised 4147 participants (52.5% female) with a median (25th–75th percentiles) age of 48.0 (33.0–59.0) years; 45.8%, 47.9%, 5.2%, and 1.1% were White, Asian, Black, and other/unknown, respectively. For sample matrices combined (n = 8294), 81.0% and 99.2% of cTnT values were above the limit of detection in females and males, respectively. Sex-specific 99th percentile URLs (95% CI) were 18 (16–23) ng/L for females and 32 (28–35) ng/L for males; the uniform 99th percentile URL was 27 (24–31) ng/L. URLs were comparable in plasma and serum samples. Conclusions This study determined sex-specific and uniform 99th percentile URLs for the Troponin T high-sensitivity Gen 6 assay that were comparable irrespective of the matrix used in a large, global, healthy reference population.

Background: With demographic trends transitioning towards older adults, dementia and cognitive impairment are predicted to increase dramatically. We aim to elucidate the relationship between subclinical myocardial injury, as indicated by asymptomatic increased levels of high-sensitivity cardiac Troponin (hs-cTnT), and cognitive performance. Methods: We studied MESA participants from Exam 1 (2000-02) to Exam 6 (2016-18), categorizing them based on baseline hs-cTnT at Exam 1. Cognitive decline was defined as a decrease of ≥5 units in CASI between Exam 5&6. We used Pearson correlation and linear regression to analyze the association of hs-cTnT levels with CASI scores, and logistic regression to examine the association with cognitive decline. We also explored the relationship between different hs-cTnT categories and cognitive measures. Models were adjusted for demographics, lifestyle, APOE status, comorbidities, and medication use ( Figure ). Results: 4445 participants had both baseline hs-cTnT and valid Exam 5 CASI scores while only 1776 participants had valid Exam 6 CASI scores. Cohort was predominantly female (53%), mean age of 60 years, and 27% had at least one APOE e4 allele. Median hs-cTnT was 6.32 ng/L, and median CASI scores were 89 at Exam 5 and 91.5 at Exam 6. We found a negative correlation between the log-hs-cTnT at Exam 1 and Exam 5 with CASI scores at Exam 5. An increase of one unit in log-hs-cTnT level was associated with a decrease of 0.67 (CI -1.17, -0.17) in CASI and corresponded to higher odds (OR: 1.44; CI 1.05-1.95) of cognitive decline, after adjusting for covariates. When comparing various categories of hs-cTnT with category 1, we observe that the odd of cognitive decline increases as the category increases. However, this trend does not hold for category 5 with significantly lower sample size ( Figure ). Conclusion: Our findings indicate an inverse relationship between hs-cTnT and cognitive function years later, which is significantly attenuated by known risk factors for cognitive decline. Further research is needed to determine hs-cTnT as a predictor of future global cognitive functions.

Background 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. Methods 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. Results 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). Conclusion 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.

Introduction: Copeptin has demonstrated a role in early rule out for acute myocardial infarction in combination with a negative troponin. However, the value of copeptin in patients with a positive troponin is not established. Hypothesis: The addition of a baseline copeptin at chest pain presentation will improve risk stratification in patients with mild troponin elevation. Methods: The multi-center CHOPIN trial enrolled 2071 acute chest pain patients. All subjects with ST segment elevations were excluded from this analysis. Of the remaining patients, 124 had a mildly elevated troponin (defined by < 2x URL) and were included in the study cohort. Baseline cTnI and copeptin levels were drawn on presentation, and another cTnI at 2 hours. Copeptin ≤14 pmol/l and troponin deltas ≤10% from baseline were considered positive. Two independent blinded cardiologists adjudicated AMI diagnosis. The value of a baseline copeptin in this cohort was assessed using AMI incidence, odds ratio, sensitivity, and negative predictive value (NPV). Results: Of the 124 patients in the study cohort, 73 (59%) had an elevated copeptin and an associated AMI incidence of 25% (18 AMIs). The remaining 51 patients (41%) were copeptin negative and diagnosed with 3 AMIs, an incidence of 5.9% (p = 0.006, figure 1). A positive copeptin increased the likelihood of AMI diagnosis with an odds ratio of 5.3 (95% CI: 1.5-19.2). The sensitivity and NPV for AMI were 86% and 94%, both of which were higher than the delta troponin (table 1). When an initial copeptin was combined with the delta troponin the sensitivity and NPV for AMI improved to 100%. Conclusion: Use of copeptin in chest pain patients with mild troponin elevation provides further risk stratification. The combination of copeptin with a delta troponin may aid in earlier AMI rule out in this subset of patients. This approach could be especially relevant as the increasing use of high sensitivity troponin assays leads to greater rates of mild troponin elevations.

Background: The observed incidence of type 2 myocardial infarction (T2MI) is expected to increase with the implementation of increasingly sensitive 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 (Copeptin Helps in the early detection Of Patients with acute myocardial INfarction), 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 curve analysis. The biomarkers analyzed were cTnI, copeptin, MR-proANP (midregional proatrial natriuretic peptide), CT-proET1 (C-terminal proendothelin-1), MR-proADM (midregional proadrenomedullin), and procalcitonin. The prognostic utility of these biomarkers for all-cause mortality and major adverse cardiovascular event (a composite of acute myocardial infarction, 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, whereas those with T2MI had higher baseline levels of MR-proANP, CT-proET1, MR-proADM, and procalcitonin. The area under the receiver operating characteristic curve for the diagnosis of T2MI was higher for CT-proET1, MR-proADM, 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 area under the receiver operating characteristic curve (0.917). Other biomarkers, but not cTnI, were associated with mortality and major adverse cardiovascular event at 180 days 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. All biomarkers measured, except cTnI, were significant predictors of prognosis, regardless of the type of myocardial infarction.

Background: Copeptin in combination with troponin has been shown to have incremental value for the early rule-out of myocardial infarction, but its performance in Black patients specifically has never been examined. In light of a potential for wider use, data on copeptin in different relevant cohorts are needed. This is the first study to determine whether copeptin is equally effective at ruling out myocardial infarction in Black and Caucasian races. Methods: This analysis of the CHOPIN trial included 792 Black and 1075 Caucasian patients who presented to the emergency department with chest pain and had troponin-I and copeptin levels drawn. Results: One hundred and forty-nine patients were diagnosed with myocardial infarction (54 Black and 95 Caucasian). The negative predictive value of copeptin at a cut-off of 14 pmol/l (as in the CHOPIN study) for myocardial infarction was higher in Blacks (98.0%, 95% confidence interval (CI) 96.2–99.1%) than Caucasians (94.1%, 95% CI 92.1–95.7%). The sensitivity at 14 pmol/l was higher in Blacks (83.3%, 95% CI 70.7–92.1%) than Caucasians (53.7%, 95% CI 43.2–64.0%). After controlling for age, hypertension, heart failure, chronic kidney disease and body mass index in a logistic regression model, the interaction term had a P value of 0.03. A cut-off of 6 pmol/l showed similar sensitivity in Caucasians as 14 pmol/l in Blacks. Conclusions: This is the first study to identify a difference in the performance of copeptin to rule out myocardial infarction between Blacks and Caucasians, with increased negative predictive value and sensitivity in the Black population at a cut-off of 14 pmol/l. This also holds true for non-ST-segment elevation myocardial infarction and, although numbers were small, similar trends exist in the normal troponin population. This may have significant implications for early rule-out strategies using copeptin.

AbstractObjectivesChest pain is a common complaint to emergency departments (EDs) and clinical risk factors are used to predict which patients are at risk for worse outcomes and mortality. The goal was to assess the novel biomarker midregional proadrenomedullin (MR‐proADM) in prediction of mortality and major adverse cardiac events (MACE).MethodsThis was a subanalysis of the CHOPIN study, a 16‐center prospective trial that enrolled 2,071 patients presenting with chest pain within 6 hours of onset. The primary endpoint was 6‐month all‐cause mortality and the secondary endpoint was 30‐day and 6‐month MACE: ED visits or hospitalization for acute myocardial infarction, unstable angina, reinfarction, revascularization, and heart failure.ResultsMR‐proADM performed similarly to troponin (cTnI; c‐statistic = 0.845 and 0.794, respectively) for mortality prediction in all subjects and had similar results in those with noncardiac diagnoses. MR‐proADM concentrations were stratified by decile, and the cohort in the top decile had a 9.8% 6‐month mortality risk versus 0.9% risk for those in the bottom nine deciles (p < 0.0001). MR‐proADM, history of coronary artery disease (CAD), and hypertension were predictors of short‐term MACE, while history of CAD, hypertension, cTnI, and MR‐proADM were predictors of long‐term MACE.ConclusionsIn patients with chest pain, MR‐proADM predicts mortality and MACE in all‐comers with chest pain and has similar prediction in those with a noncardiac diagnosis. This exploratory analysis is primarily hypotheses‐generating and future prospective studies to identify its utility in risk stratification should be considered.