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

Combining glucose and high-sensitivity cardiac troponin in the early diagnosis of acute myocardial infarction

Glucose is a universally available inexpensive biomarker, which is increased as part of the physiological stress response to acute myocardial infarction (AMI) and may therefore help in its early diagnosis. To test this hypothesis, glucose, high-sensitivity cardiac troponin (hs-cTn) T, and hs-cTnI were measured in consecutive patients presenting with acute chest discomfort to the emergency department (ED) and enrolled in a large international diagnostic study (NCT00470587). Two independent cardiologists centrally adjudicated the final diagnosis using all clinical data, including serial hs-cTnT measurements, cardiac imaging and clinical follow-up. The primary diagnostic endpoint was index non-ST-segment elevation MI (NSTEMI). Prognostic endpoints were all-cause death, and cardiovascular (CV) death or future AMI, all within 730-days. Among 5639 eligible patients, NSTEMI was the adjudicated final diagnosis in 1051 (18.6%) patients. Diagnostic accuracy quantified using the area under the receiver-operating characteristics curve (AUC) for the combination of glucose with hs-cTnT and glucose with hs-cTnI was very high, but not higher versus that of hs-cTn alone (glucose/hs-cTnT 0.930 [95% CI 0.922-0.937] versus hs-cTnT 0.929 [95% CI 0.922-0.937]; glucose/hs-cTnI 0.944 [95% CI 0.937-0.951] versus hs-cTnI 0.944 [95% CI 0.937-0.951]). In early-presenters, a dual-marker strategy (glucose < 7 mmol/L and hs-cTnT < 5/hs-cTnI < 4 ng/L) provided very high and comparable sensitivity to slightly lower hs-cTn concentrations (cTnT/I < 4/3 ng/L) alone, and possibly even higher efficacy. Glucose was an independent predictor of 730-days endpoints. Our results showed that a dual marker strategy of glucose and hs-cTn did not increase the diagnostic accuracy when used continuously. However, a cutoff approach combining glucose and hs-cTn may provide diagnostic utility for patients presenting ≤ 3 h after onset of symptoms, also providing important prognostic information.

Machine learning for early prediction of acute myocardial infarction or death in acute chest pain patients using electrocardiogram and blood tests at presentation

AIMS

In the present study, we aimed to evaluate the performance of machine learning (ML) models for identification of acute myocardial infarction (AMI) or death within 30 days among emergency department (ED) chest pain patients.

METHODS AND RESULTS

Using data from 9519 consecutive ED chest pain patients, we created ML models based on logistic regression or artificial neural networks. Model inputs included sex, age, ECG and the first blood tests at patient presentation: High sensitivity TnT (hs-cTnT), glucose, creatinine, and hemoglobin. For a safe rule-out, the models were adapted to achieve a sensitivity > 99% and a negative predictive value (NPV) > 99.5% for 30-day AMI/death. For rule-in, we set the models to achieve a specificity > 90% and a positive predictive value (PPV) of > 70%. The models were also compared with the 0 h arm of the European Society of Cardiology algorithm (ESC 0 h); An initial hs-cTnT < 5 ng/L for rule-out and ≥ 52 ng/L for rule-in. A convolutional neural network was the best model and identified 55% of the patients for rule-out and 5.3% for rule-in, while maintaining the required sensitivity, specificity, NPV and PPV levels. ESC 0 h failed to reach these performance levels.

DISCUSSION

An ML model based on age, sex, ECG and blood tests at ED arrival can identify six out of ten chest pain patients for safe early rule-out or rule-in with no need for serial blood tests. Future studies should attempt to improve these ML models further, e.g. by including additional input data.

Adding stress biomarkers to high-sensitivity cardiac troponin for rapid non-ST-elevation myocardial infarction rule-out protocols

AIMS

This study tested the hypothesis that combining stress-induced biomarkers (copeptin or glucose) with high-sensitivity cardiac troponin (hs-cTn) increases diagnostic accuracy for non-ST-elevation myocardial infarction (NSTEMI) in patients presenting to the emergency department.

METHODS AND RESULTS

The ability to rule-out NSTEMI for combinations of baseline hs-cTnT or hs-cTnI with copeptin or glucose was compared with the European Society of Cardiology (ESC) hs-cTnT/I-only rule-out algorithms in two independent (one Norwegian and one international multicentre) diagnostic studies. Among 959 patients (median age 64 years, 60.5% male) with suspected NSTEMI in the Norwegian cohort, 13% had NSTEMI. Adding copeptin or glucose to hs-cTnT/I as a continuous variable did not improve discrimination as quantified by the area under the curve {e.g. hs-cTnT/copeptin 0.91 [95% confidence interval (CI) 0.89-0.93] vs. hs-cTnT alone 0.91 (95% CI 0.89-0.93); hs-cTnI/copeptin 0.85 (95% CI 0.82-0.87) vs. hs-cTnI alone 0.93 (95% CI 0.91-0.95)}, nor did adding copeptin <9 mmol/L or glucose <5.6 mmol/L increase the sensitivity of the rule-out provided by hs-cTnT <5 ng/L or hs-cTnI <4 ng/L in patients presenting more than 3 h after chest pain onset (target population in the ESC-0 h-algorithm). The combination decreased rule-out efficacy significantly (both P < 0.01). These findings were confirmed among 1272 patients (median age 62 years, 69.3% male) with suspected NSTEMI in the international validation cohort, of which 20.7% had NSTEMI. A trend towards increased sensitivity for the hs-cTnT/I/copeptin combinations (97-100% vs. 91-97% for the ESC-0 h-rule-out cut-offs) was observed in the Norwegian cohort.

CONCLUSION

Adding copeptin or glucose to hs-cTnT/I did not increase diagnostic performance when compared with current ESC guideline hs-cTnT/I-only 0 h-algorithms.

Glucose and high-sensitivity troponin T predict a low risk of major adverse cardiac events in emergency department chest pain patients

Background. Glucose is emerging as a biomarker for early and safe rule-out of acute myocardial infarction in emergency department (ED) chest pain patients. We evaluated the diagnostic accuracy of dual testing with high sensitivity TnT (hs-cTnT) and glucose for prediction of major adverse cardiac events (MACE) within 30 days. Methods. This was a secondary analysis of a single-center prospective observational study of 1167 ED chest-pain patients with hs-cTnT and glucose testing at presentation (0 h), and hs-cTnT 1 h later. We tested the addition of glucose <5.6 mmol/L to three MACE rule-out strategies: hs-cTnT <5 ng/L, ≤14 ng/L or a 0 h/1h algorithm, i.e. initial hs-cTnT <12 ng/L with a 1 h change of <3 ng/L. We also tested the addition of glucose ≥11mmol/L to three rule-in strategies: hs-cTnT ≥52 ng/L, a 1 h change ≥5 ng/L or hs-cTnT >14 ng/L. The outcomes were 30-day MACE and 30-day MACE without UA. Results. Two dual-testing approaches reached our target NPV for rule-out: A 0 h hs-cTnT ≤14 ng/L and glucose <5.6 mmol/L identified 252 patients (24.4%) with a 98.8% NPV for 30-day MACE and 99.6% for MACE without UA. The 0 h/1h hs-cTnT algorithm combined with glucose identified 240 patients (23.2%) with a 99.2% NPV for 30-day MACE and 100.0% for MACE without UA. No dual rule-in strategy performed better than using hs-cTnT alone. Conclusions. A combination of hs-cTnT and blood glucose at presentation can be used to identify almost ¼ of ED chest pain patients with a very low risk of 30-day MACE where further testing is not needed. Adding glucose did not improve the rule-in of 30-day MACE.

High-sensitivity troponin assays for early rule-out of acute myocardial infarction in people with acute chest pain: a systematic review and economic evaluation

BACKGROUND

Early diagnosis of acute myocardial infarction is important, but only 20% of emergency admissions for chest pain will actually have an acute myocardial infarction. High-sensitivity cardiac troponin assays may allow rapid rule out of myocardial infarction and avoid unnecessary hospital admissions.

OBJECTIVES

To assess the clinical effectiveness and cost-effectiveness of high-sensitivity cardiac troponin assays for the management of adults presenting with acute chest pain, in particular for the early rule-out of acute myocardial infarction.

METHODS

Sixteen databases were searched up to September 2019. Review methods followed published guidelines. Studies were assessed for quality using appropriate risk-of-bias tools. The bivariate model was used to estimate summary sensitivity and specificity for meta-analyses involving four or more studies; otherwise, random-effects logistic regression was used. The health economic analysis considered the long-term costs and quality-adjusted life-years associated with different troponin testing methods. The de novo model consisted of a decision tree and a state-transition cohort model. A lifetime time horizon (of 60 years) was used.

RESULTS

Thirty-seven studies (123 publications) were included in the review. The high-sensitivity cardiac troponin test strategies evaluated are defined by the combination of four factors (i.e. assay, number and timing of tests, and threshold concentration), resulting in a large number of possible combinations. Clinical opinion indicated a minimum clinically acceptable sensitivity of 97%. When considering single test strategies, only those using a threshold at or near to the limit of detection for the assay, in a sample taken at presentation, met the minimum clinically acceptable sensitivity criterion. The majority of the multiple test strategies that met this criterion comprised an initial rule-out step, based on high-sensitivity cardiac troponin levels in a sample taken on presentation and a minimum symptom duration, and a second stage for patients not meeting the initial rule-out criteria, based on presentation levels of high-sensitivity cardiac troponin and absolute change after 1, 2 or 3 hours. Two large cluster randomised controlled trials found that implementation of an early rule-out pathway for myocardial infarction reduced length of stay and rate of hospital admission without increasing cardiac events. In the base-case analysis, standard troponin testing was both the most effective and the most costly. Other testing strategies with a sensitivity of 100% (subject to uncertainty) were almost equally effective, resulting in the same life-year and quality-adjusted life-year gain at up to four decimal places. Comparisons based on the next best alternative showed that for willingness-to-pay values below £8455 per quality-adjusted life-year, the Access High Sensitivity Troponin I (Beckman Coulter, Brea, CA, USA) [(symptoms > 3 hours AND < 4 ng/l at 0 hours) OR (< 5 ng/l AND Δ < 5 ng/l at 0 to 2 hours)] would be cost-effective. For thresholds between £8455 and £20,190 per quality-adjusted life-year, the Elecsys® Troponin-T high sensitive (Roche, Basel, Switzerland) (< 12 ng/l at 0 hours AND Δ < 3 ng/l at 0 to 1 hours) would be cost-effective. For a threshold > £20,190 per quality-adjusted life-year, the Dimension Vista® High-Sensitivity Troponin I (Siemens Healthcare, Erlangen, Germany) (< 5 ng/l at 0 hours AND Δ < 2 ng/l at 0 to 1 hours) would be cost-effective.

CONCLUSIONS

High-sensitivity cardiac troponin testing may be cost-effective compared with standard troponin testing.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42019154716.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Evidence Synthesis programme and will be published in full in Health Technology Assessment; Vol. 25, No. 33. See the NIHR Journals Library website for further project information.

Clinical chemistry score versus high-sensitivity cardiac troponin I and T tests alone to identify patients at low or high risk for myocardial infarction or death at presentation to the emergency department

BACKGROUND

Testing for high-sensitivity cardiac troponin (hs-cTn) may assist triage and clinical decision-making in patients presenting to the emergency department with symptoms of acute coronary syndrome; however, this could result in the misclassification of risk because of analytical variation or laboratory error. We sought to evaluate a new laboratory-based risk-stratification tool that incorporates tests for hs-cTn, glucose level and estimated glomerular filtration rate to identify patients at risk of myocardial infarction or death when presenting to the emergency department.

METHODS

We constructed the clinical chemistry score (CCS) (range 0-5 points) and validated it as a predictor of 30-day myocardial infarction (MI) or death using data from 4 cohort studies involving patients who presented to the emergency department with symptoms suggestive of acute coronary syndrome. We calculated diagnostic parameters for the CCS score separately using high-sensitivity cardiac troponin I (hs-cTnI) and high-sensitivity cardiac troponin T (hs-cTnT).

RESULTS

For the combined cohorts (n = 4245), 17.1% of participants had an MI or died within 30 days. A CCS score of 0 points best identified low-risk participants: the hs-cTnI CCS had a sensitivity of 100% (95% confidence interval [CI] 99.5%-100%), with 8.9% (95% CI 8.1%-9.8%) of the population classified as being at low risk of MI or death within 30 days; the hs-cTnT CCS had a sensitivity of 99.9% (95% CI 99.2%-100%), with 10.5% (95% CI 9.6%-11.4%) of the population classified as being at low risk. The CCS had better sensitivity than hs-cTn alone (hs-cTnI < 5 ng/L: 96.6%, 95% CI 95.0%-97.8%; hs-cTnT < 6 ng/L: 98.2%, 95% CI 97.0%-99.0%). A CCS score of 5 points best identified patients at high risk (hs-cTnI CCS: specificity 96.6%, 95% CI 96.0%-97.2%; 11.2% [95% CI 10.3%-12.2%] of the population classified as being at high risk; hs-cTnT CCS: specificity 94.0%, 95% CI 93.1%-94.7%; 13.1% [95% CI 12.1%-14.1%] of the population classified as being at high risk) compared with using the overall 99th percentiles for the hs-cTn assays (specificity of hs-cTnI 93.2%, 95% CI 92.3-94.0; specificity of hs-cTnT 73.8%, 95% CI 72.3-75.2).

INTERPRETATION

The CCS score at the chosen cut-offs was more sensitive and specific than hs-cTn alone for risk stratification of patients presenting to the emergency department with suspected acute coronary syndrome. Study registration: ClinicalTrials.gov, nos. NCT01994577; NCT02355457.

Age-sex distribution of patients with high-sensitivity troponin T levels below the 99th percentile

Background

Recently, very low concentrations of high-sensitivity cardiac troponin T (hs-cTnT), below the 99th percentile, have been used to immediately exclude acute myocardial infarction in certain patients without taking their age and sex into consideration.

Results

The hs-cTnT values below the 99th percentile (≤ 14 ng/L) were higher in men (p = 0.000) and significantly increased with age (p = 0.000) among both men and women. In addition, hs-cTnT was positively associated with age (r = 0.459, p = 0.000), myoglobin (r = 0.392, p = 0.000), and creatine kinase-MB (r = 0.133, p = 0.000). Moreover, males were younger (p = 0.001) and had higher myoglobin (p = 0.000) and creatine kinase-MB (p = 0.000) concentrations than females.

Materials and Methods

A total of 5585 consecutive subjects who presented with non-traumatic chest pain/discomfort to the inpatient, outpatient, or emergency department and who underwent high-sensitivity troponin T, myoglobin and creatine kinase-MB testing at presentation, with hs-cTnT below the 99thpercentile (≤ 14 ng/L), were eligible for enrollment.

Conclusions

We suggest that patients’ age, sex and levels of myocardial injury biomarkers should be taken into consideration when ruling out acute myocardial infarction and/or adverse prognostic implications in patients who have very low hs-cTnT concentrations.

Rule-In and Rule-Out of Myocardial Infarction Using Cardiac Troponin and Glycemic Biomarkers in Patients with Symptoms Suggestive of Acute Coronary Syndrome

BACKGROUND

Early rule-in/rule-out of myocardial infarction (MI) in patients presenting to the emergency department (ED) is important for patient care and resource allocation. Given that dysglycemia is a strong risk factor for MI, we sought to explore and compare different combinations of cardiac troponin (cTn) cutoffs with glycemic markers for the early rule-in/rule-out of MI.

METHODS

We included ED patients (n = 1137) with symptoms suggestive of acute coronary syndrome (ACS) who had cTnI, high-sensitivity cTnI (hs-cTnI), hs-cTnT, glucose, and hemoglobin A_1c (Hb A_1c) measurements. We derived rule-in/rule-out algorithms using different combinations of ROC-derived and literature cutoffs for rule-in and rule-out of MI within 7 days after presentation. These algorithms were then tested for MI/cardiovascular death and ACS/cardiovascular death at 7 days. ROC curves, sensitivity, specificity, likelihood ratios, positive and negative predictive values (PPV and NPV), and CIs were determined for various biomarker combinations.

RESULTS

MI was diagnosed in 133 patients (11.7%; 95% CI, 9.8-13.8). The algorithms that included cTn and glucose produced the greatest number of patients ruled out/ruled in for MI and yielded sensitivity ≥99%, NPV ≥99.5%, specificity ≥99%, and PPV ≥80%. This diagnostic performance was maintained for MI/cardiovascular death but not for ACS/cardiovascular death. The addition of hemoglobin A_1c (Hb A_1c) (≥6.5%) to these algorithms did not change these estimates; however, 50 patients with previously unknown diabetes may have been identified if Hb A_1c was measured.

CONCLUSIONS

Algorithms incorporating glucose with cTn may lead to an earlier MI diagnosis and rule-out for MI/cardiovascular death. Addition of Hb A_1c into these algorithms allows for identification of diabetes. Future studies extending these findings are needed for ACS/cardiovascular death. ClinicalTrials.gov identifier: NCT01994577.

Heart Fatty Acid Binding Protein and cardiac troponin: development of an optimal rule-out strategy for acute myocardial infarction

BACKGROUND

Improved ability to rapidly rule-out Acute Myocardial Infarction (AMI) in patients presenting with chest pain will promote decongestion of the Emergency Department (ED) and reduce unnecessary hospital admissions. We assessed a new commercial Heart Fatty Acid Binding Protein (H-FABP) assay for additional diagnostic value when combined with cardiac troponin (using a high sensitivity assay).

METHODS

H-FABP and high-sensitivity troponins I (hs-cTnI) and T (hs-cTnT) were measured in samples taken on-presentation from patients, attending the ED, with symptoms triggering investigation for possible acute coronary syndrome. The optimal combination of H-FABP with each hs-cTn was defined as that which maximized the proportion of patients with a negative test (low-risk) whilst maintaining at least 99 % sensitivity for AMI. A negative test comprised both H-FABP and hs-cTn below the chosen threshold in the absence of ischemic changes on the ECG.

RESULTS

One thousand seventy-nine patients were recruited including 248 with AMI. H-FABP < 4.3 ng/mL plus hs-cTnI < 10.0 ng/L together with a negative ECG maintained >99 % sensitivity for AMI whilst classifying 40.9 % of patients as low-risk. The combination of H-FABP < 3.9 ng/mL and hs-cTnT < 7.6 ng/L with a negative ECG maintained the same sensitivity whilst classifying 32.1 % of patients as low risk.

CONCLUSIONS

In patients requiring rule-out of AMI, the addition of H-FABP to hs-cTn at presentation (in the absence of new ischaemic ECG findings) may accelerate clinical diagnostic decision making by identifying up to 40 % of such patients as low-risk for AMI on the basis of blood tests performed on presentation. If implemented this has the potential to significantly accelerate triaging of patients for early discharge from the ED.

High-Sensitivity Cardiac Troponin T Concentrations below the Limit of Detection to Exclude Acute Myocardial Infarction: A Prospective Evaluation

BACKGROUND

Initial reports suggest that concentrations of high-sensitivity cardiac troponin T (hs-cTnT) (Roche Diagnostics Elecsys®) below the limit of blank (LoB) (3 ng/L) or limit of detection (LoD) (5 ng/L) of the assay have almost 100% negative predictive value (NPV) for acute myocardial infarction (AMI), particularly among patients without electrocardiograph (ECG) evidence of ischemia. We aimed to prospectively validate those findings.

METHODS

We included adults presenting to the emergency department with suspected cardiac chest pain. Standard troponin T (cTnT) and hs-cTnT (both Roche Elecsys) were tested in samples drawn on arrival. The primary outcome was AMI, adjudicated by 2 investigators on the basis of clinical data and ≥12-h cTnT testing. We also evaluated diagnostic performance when AMI was readjudicated on the basis of hs-cTnT (≥12-h) concentrations.

RESULTS

Of 463 patients included, 79 (17.1%) had AMI. Twenty-four patients (5.2%) had hs-cTnT concentrations below the LoB, although none had AMI. Ninety-six patients (20.7%) had hs-cTnT concentrations below the LoD, 1 of whom had AMI. Thus, diagnostic sensitivity was 98.7% (95% CI 87.5%–98.6%) and NPV was 99.0% (95% CI 94.3%–100.0%). Of the 17.3% (n = 80) patients with hs-cTnT below the LoD and no ECG ischemia, none had AMI. Thus, diagnostic sensitivity was 100.0% (95% CI 95.4%–100.0%) and NPV was 100.0% (95% CI 95.5%–100.0%). Sensitivity and NPV were maintained when AMI was readjudicated on the basis of hs-cTnT.

CONCLUSIONS

Our findings confirm that patients with nonischemic ECG and undetectable hs-cTnT at presentation have a very low probability of AMI, although the proportion of patients affected was smaller than in previous research.