A 3-Hour Diagnostic Algorithm for Non-ST-Elevation Myocardial Infarction Using High-Sensitivity Cardiac Troponin T in Unselected Older Patients Presenting to the Emergency Department

doi:10.1016/j.jamda.2012.12.005

Journal of the American Medical Directors Association

Volume 14, Issue 6, June 2013, Pages 409-416

https://doi.org/10.1016/j.jamda.2012.12.005 Get rights and content

Abstract

Objectives

To determine if an algorithm implementing a serial high-sensitive cardiac troponin T (hs-cTnT) measurement at presentation (0h) and at 3 hours after presentation (3h) is helpful for early diagnosis of non-ST-elevation myocardial infarction (NSTEMI) in older patients.

Design

Prospective observational cohort study.

Setting

An emergency department (ED) of a city hospital covering a population of approximately 1 million in Germany.

Participants

A total of 332 consecutive unselected patients were recruited, of whom 25 had one or more of the prespecified exclusion criteria and 1 had a missing hs-cTnT at 3h, resulting in a final population of 306 patients.

Measurements

In addition to clinical examination, hs-cTnT was measured at 0h and 3h. The final diagnosis of NSTEMI was adjudicated by two independent consultants and an algorithm for rule-in and rule-out of NSTEMI was developed using classification and regression tree analysis. All patients were followed-up for cardiovascular outcome within 12 months.

Results

Among 306 patients (mean age 81 ± 6 years), 38 (12%) patients had NSTEMI. Accuracy to diagnose NSTEMI was significantly higher for hs-cTnT measurements at 3h versus 0h (area under the receiver operating characteristic curve [AUC] 0.88 vs. 0.82, P = .0038) and for absolute versus relative hs-cTnT delta changes (AUC 0.89 versus 0.69, P < .001). A diagnostic algorithm using hs-cTnT values at presentation and absolute delta changes values ruled-in NSTEMI in 23% and ruled-out NSTEMI in 35% of patients. For patients neither fulfilling the rule-in nor the rule-out criteria, an observational zone was established. Cumulative 1-year survival was 79.4%, 88.5%, and 99.1% in patients classified as rule-in, observational zone, and rule-out, respectively.

Conclusion

In older patients, serial hs-cTnT measurements and absolute delta-changes at 3h were valuable for early diagnosis of NSTEMI. An algorithm ruled-in NSTEMI in one quarter of patients with high risk and ruled-out NSTEMI in one-third with low risk.

Section snippets

Study Design and Population

From January 18, 2011, to September 5, 2011, we measured hs-cTnT as part of the routine blood sampling protocol at presentation and at 3h in all consecutive nontrauma patients aged 70 years or older who were admitted to the ED of the Nuremberg city hospital. Inclusion criteria for study participation was age 70 years or older. Exclusion criteria were STEMI, planned elective coronary revascularization, hospitalization for unstable angina within the preceding 2 months, coronary-artery bypass

Clinical Characteristics

We recruited 332 patients who met the inclusion criteria, of whom 25 had one or more of the prespecified exclusion criteria, resulting in a final population of 307 patients.²⁰ In one patient, the index test hs-cTnT at 3h was missing, so that finally 306 patients, in whom both hs-cTnT at presentation and at 3h were available, were analyzed (Figure 1).

Within our study population, median hs-cTnT concentrations were 20 ng/L (IQR 9–46) and values of 14 ng/L or higher were present in 200 (65%)

Discussion

This prospective observational study examined whether consecutive older patients benefit from a new fast-track protocol and a simple algorithm for rapid rule-in and rule-out of NSTEMI. The main results of the study are as follows: (1) A fast-track protocol implementing a serial measurement at presentation and at 3h after presentation increased the specificity of hs-cTnT from 69% to 93% but reduced the sensitivity from 82% to 58% for older patients with a final diagnosis of NSTEMI. (2) Using

Conclusion

In summary, a new fast-track protocol implementing serial measurements and absolute delta changes of hs-cTnT was beneficial for early diagnosis of NSTEMI in older patients at the ED. An algorithm integrating both hs-cTnT values of less than 23 ng/L at presentation and absolute delta changes of hs-cTnT of less than 3 ng/L within the first 3h, ruled-out NSTEMI in one-third of older patients with very low risk for cardiovascular death during follow-up. Hs-cTnT values of 108 ng/L or higher at

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Cited by (14)

Contemporary Emergency Department Management of Patients with Chest Pain: A Concise Review and Guide for the High-Sensitivity Troponin Era
2018, Canadian Journal of Cardiology
Citation Excerpt :
Given that the differences between Δ thresholds to rule in or rule out AMI are larger for 2-hour algorithms than for 1-hour algorithms, 2-hour algorithms may be less prone to misclassification owing simply to analytical variability.43,45 Three-hour algorithms have also been proposed, using absolute hs-cTn levels less than the 99th percentile at 0 and 3 hours or a combination of a low initial concentration and minimal Δs over the 3-hour interval.21,50-53 The sensitivities for AMI generated by algorithms relying simply on troponin levels less than the 99th percentile at both 0 and 3 hours seem lower than those generated by other algorithms that incorporate serial changes in hs-cTn but typically still maintain high negative predictive values.
This article synthesizes current best evidence for the evaluation of patients with suspected acute coronary syndrome (ACS) using high-sensitivity troponin assays, enabling physicians to effectively incorporate them into practice. Unlike conventional assays, high-sensitivity assays can precisely measure blood cardiac troponin concentrations in the vast majority of healthy individuals, facilitating the creation of rapid diagnostic algorithms. Very low troponin concentrations on presentation accurately rule out acute myocardial infarction (AMI) and enable the discharge of approximately 20% of patients after a single test, whereas an additional 30%-40% of patients can be safely discharged after short-interval serial sampling in as little as 1 or 2 hours. In contrast, highly abnormal troponin concentrations on presentation (more than 5 times the upper reference limit) or rapidly rising levels on serial testing can rapidly rule in AMI with high specificity. However, approximately one-third of patients remain in a biomarker-indeterminate “observation zone” even after serial sampling. These patients pose a disposition challenge to clinicians because although the differential diagnosis of elevated troponin concentrations is broad, these patients have an increased risk for short-term major adverse cardiac events. Use of repeated serial troponin sampling and structured clinical prediction tools may assist disposition for these patients, because no validated pathways currently exist to guide clinicians. Ongoing research to tailor diagnostic thresholds to individual patient characteristics may enable improved diagnostic accuracy and usher in a new era of personalized medicine in the evaluation of suspected ACS.
Le présent article fait la synthèse des meilleures données probantes actuelles sur l’évaluation des patients montrant une suspicion du syndrome coronarien aigu (SCA) au moyen des dosages de la troponine de haute sensibilité, permettant ainsi aux médecins de les incorporer concrètement à la pratique. Contrairement aux dosages traditionnels, les dosages de haute sensibilité peuvent donner des mesures précises des concentrations de troponine cardiaque dans le sang chez la plupart des individus en santé, ce qui facilite la création d’algorithmes de diagnostic rapide. De très faibles concentrations de troponine à l’admission écartent rigoureusement l’infarctus aigu du myocarde (IAM) et permettent à environ 20 % des patients d’obtenir leur congé de l’hôpital après une seule analyse, et en plus à 30 % à 40 % des patients d’obtenir leur congé en toute sécurité après le prélèvement d’échantillons en série dans un intervalle aussi court que 1 ou 2 heures. En revanche, des concentrations anormalement élevées de la troponine à l’admission (plus que 5 fois le seuil de référence supérieur) ou des concentrations qui augmentent rapidement au cours des analyses en série dont la spécificité est élevée peuvent confirmer en peu de temps le diagnostic d’IAM. Toutefois, environ un tiers des patients demeurent dans une « zone d’observation » des biomarqueurs pour une période indéterminée même après les échantillons en série. Ces patients posent un problème aux cliniciens quant à leur destination à la sortie de l’hôpital, car bien que le diagnostic différentiel des concentrations élevées de troponine soit large, ces patients sont exposés à un risque accru d’événements cardiaques indésirables majeurs à court terme. La répétition des échantillons en série de la troponine et l’utilisation d’outils de prédiction clinique structurés peuvent être utiles aux cliniciens pour se prononcer sur la destination de ces patients à leur sortie de l’hôpital, puisqu’aucun cheminement validé n’existe actuellement pour les conseiller. La recherche en cours sur l’adaptation des seuils diagnostiques aux caractéristiques de chaque patient peut favoriser l’amélioration de l’exactitude diagnostique et marquer le début d’une nouvelle ère de la médecine personnalisée dans l’évaluation d’une suspicion de SCA.
Diagnostic and prognostic value of high-sensitivity cardiac troponin T in patients with syncope
2015, American Journal of Medicine
Citation Excerpt :
Of note, the precise mechanisms of increased cTnThs levels in patients with syncope are not well characterized: Approximately 50% of patients with syncope in our cohort are aged more than 70 years, and approximately 25% are aged more than 80 years. It is well known that cTnThs levels are elevated in elderly patients presenting to the emergency department possibly because of heart failure, a high atherosclerotic load, or loss of renal function.42,43 Thus, it is tempting to speculate that the increased rate of comorbid conditions in the patients in our cohort is associated with increased cTnThs levels.
We examined the diagnostic and predictive value of high-sensitivity cardiac troponin T (cTnThs) in patients with syncope.
We performed an analysis of consecutive patients with syncope presenting to the emergency department. The primary end point was the accuracy to diagnose a cardiac syncope. In addition, the study explored the prognostic relevance of cTnThs in patients with cardiac and noncardiac syncope.
A total of 360 patients were enrolled (median age, 70.5 years; male, 55.8%; 23.9% aged >80 years). Cardiac syncope was present in 22% of patients, reflex syncope was present in 40% of patients, syncope due to orthostatic hypotension was present in 20% of patients, and unexplained syncope was present in 17.5% of patients. A total of 148 patients (41%) had cTnThs levels above the 99% confidence interval (CI) (cutoff point). The diagnostic accuracy for cTnThs levels to determine the diagnosis of cardiac syncope was quantified by the area under the curve (0.77; CI, 0.72-0.83; P < .001). A comparable area under the curve (0.78; CI, 0.73-0.83; P < .001) was obtained for the predictive value of cTnThs levels within 30 days: Patients with increased cTnThs levels had a 52% likelihood for adverse events, patients with cTnThs levels below the cutoff point had a low risk (negative predictive value, 83.5%). Increased cTnThs levels indicate adverse prognosis in patients with noncardiac causes of syncope, but not in patients with cardiac syncope being a risk factor for adverse outcome by itself.
Patients with syncope presenting to the emergency department have a high proportion of life-threatening conditions. cTnThs levels show a limited diagnostic and predictive accuracy for the identification of patients with syncope at high risk.
The global prevalence of myocardial infarction: a systematic review and meta-analysis
2023, BMC Cardiovascular Disorders
Exploring biomarkers in routine diagnostics for the risk stratification of older patients in the Chest Pain Unit: A prospective cohort study
2022, BMJ Open
Performance of the European Society of Cardiology 0/1-Hour, 0/2-Hour, and 0/3-Hour Algorithms for Rapid Triage of Acute Myocardial Infarction An International Collaborative Meta-analysis
2022, Annals of Internal Medicine
Working group on myocardial markers (Gds MM) of the Italian society of clinical pathology and laboratory medicine (SIPMeL). Recommendations for the use of myocardial markers in NSTEMI. Second Part: Evidence for diagnosis
2020, Rivista Italiana della Medicina di Laboratorio

View all citing articles on Scopus

: This study was funded by Robert-Bosch-Foundation, Stuttgart, Germany.

: ClinicalTrials.gov Identifier: NCT01370395.

View full text

Original StudyA 3-Hour Diagnostic Algorithm for Non-ST-Elevation Myocardial Infarction Using High-Sensitivity Cardiac Troponin T in Unselected Older Patients Presenting to the Emergency Department

Abstract

Objectives

Design

Setting

Participants

Measurements

Results

Conclusion

Section snippets

Study Design and Population

Clinical Characteristics

Discussion

Conclusion

J Am Coll Cardiol

Am Heart J

J Chronic Dis

Am J Med

Clin Chim Acta

Symptoms of myocardial infarction in old age: Clinical case, retrospective and prospective studies

Age Ageing

Incidence and distribution of occluded culprit arteries and impact of coronary collaterals on outcome in patients with non-ST-segment elevation myocardial infarction and early invasive treatment strategy

Clin Res Cardiol

Age-related differences in the use of guideline-recommended medical and interventional therapies for acute coronary syndromes: A cohort study

J Am Geriatr Soc

Early detection of non-st-elevation myocardial infarction in geriatric patients by a new high-sensitive cardiac troponin T assay

Aging Clin Exp Res

Third universal definition of myocardial infarction

Eur Heart J

Troponin T percentiles from a random population sample, emergency room patients and patients with myocardial infarction

Clin Chem

High-sensitivity troponin assays in the evaluation of patients with acute chest pain in the emergency department

Clin Chem Lab Med

Utility of absolute and relative changes in cardiac troponin concentrations in the early diagnosis of acute myocardial infarction/clinical perspective

Circulation

Absolute and relative kinetic changes of high-sensitivity cardiac troponin T in acute coronary syndrome and in patients with increased troponin in the absence of acute coronary syndrome

Clin Chem

Functional evaluation: The Barthel index

Md State Med J

Original Study
A 3-Hour Diagnostic Algorithm for Non-ST-Elevation Myocardial Infarction Using High-Sensitivity Cardiac Troponin T in Unselected Older Patients Presenting to the Emergency Department