Safety and efficacy of the European Society of Cardiology 0/1-hour algorithm for diagnosis of myocardial infarction: systematic review and meta-analysis

Clinical decision aids and computed tomography coronary angiography in patients with suspected acute coronary syndrome

BACKGROUND

The HEART score, the T-MACS model and the GRACE score support early decision-making for acute chest pain, which could be complemented by CT coronary angiography (CTCA). However, their performance has not been directly compared.

METHODS

In this secondary analysis of a multicentre randomised controlled trial of early CTCA in intermediate-risk patients with suspected acute coronary syndrome, C-statistics and performance metrics (using the predefined cut-offs) of clinical decision aids and CTCA, alone and then in combination, for the index hospital diagnosis of acute coronary syndrome and for 30-day coronary revascularisation were assessed in those who underwent CTCA and had complete data.

RESULTS

Among 699 patients, 358 (51%) had an index hospital diagnosis of acute coronary syndrome, for which the C-statistic was higher for CTCA (0.80), followed by the T-MACS model (0.78), the HEART score (0.74) and the GRACE score (0.60). The negative predictive value was higher for the absence of coronary artery disease on CTCA (0.90) or a T-MACS estimate of <0.05 (0.83) than a HEART score of <4 (0.81) and a GRACE score of <109 (0.55). For 30-day coronary revascularisation, CTCA had the greatest C-statistic (0.80) with a negative predictive value of 0.96 and 0.92 in the absence of coronary artery disease and obstructive coronary artery disease, respectively. The combination of the T-MACS estimates and the CTCA findings was most discriminative for the index hospital diagnosis of acute coronary syndrome (C-statistic, 0.88) and predictive of 30-day coronary revascularisation (C-statistic, 0.85). No patients with a T-MACS estimate of <0.05 and normal coronary arteries had acute coronary syndrome during index hospitalisation or underwent coronary revascularisation within 30 days.

CONCLUSIONS

In intermediate-risk patients with suspected acute coronary syndrome, the T-MACS model combined with CTCA improved discrimination of the index hospital diagnosis of acute coronary syndrome and prediction of 30-day coronary revascularisation.

TRIAL REGISTRATION NUMBER

NCT02284191.

Diagnostic performance of a point of care high-sensitivity cardiac troponin I assay and single measurement evaluation to rule out and rule in acute coronary syndrome

OBJECTIVES

About 10 million individuals in USA presented annually in the emergency department (ED) with chest pain or with signs and symptoms of acute coronary syndrome (ACS). The advent of point of care (POC) devices, able to measure high sensitivity troponin, are a very interesting tool in the ED setting for its rapid turnaround time (<10 min).

METHODS

The present study evaluates the diagnostic performance of the Atellica VTLi (Siemens) in real life setting using the clinical data derived from integrated diagnoses of emergency room staff and cardiologist and in comparison with standard laboratory hs-cTnT assay (Cobas 8000, Elecsys, Roche). 966 patients admitted to the emergency department of "G. Mazzini Hospital" in Teramo, Italy, from July 27, 2022, through June 09, 2023, were enrolled.

RESULTS

The diagnostic performance of POC hs-cTnI was evaluated. An appropriate POC hs-cTnI threshold values <4 ng/L supplied a sensitivity and an NPV of 100 % (95 % CI: 99.5-100) in order to achieve rapid rule out for MI through a single measurement at patient presentation in the ED. Furthermore, a derivation POC hs-cTnI concentration >54 ng/L provided a specificity of 97.2 % (95 % CI: 95.9-98.1) and a PPV of 43.5 % (95 % CI: 40.3-46.7) for ruling in MI.

CONCLUSIONS

This platform showed comparable diagnostic performance for myocardial infarction to the central laboratory. Our data suggest the possible use of the Atellica VTLi hs-cTnI POC assay either in emergency department of urban medical centre, either in rural hospital for triage and patient management.

Management and outcomes with 5-year mortality of patients with mildly elevated high-sensitivity troponin T levels not meeting criteria for myocardial infarction

OBJECTIVES

To examine management and outcomes of patients presenting to EDs with symptoms suggestive of acute coronary syndrome, who have mild non-dynamically elevated high-sensitivity troponin T (HsTnT) levels, not meeting the fourth universal definition of myocardial infarction (MI) criteria (observation group).

METHODS

Consecutive patients presenting to the ED with symptoms suggestive of acute coronary syndrome at Liverpool Hospital, Sydney, Australia, those having ≥2 HsTnT levels after initial assessment were adjudicated according to the fourth universal definition of MI, as MI ruled-in, MI ruled-out, or myocardial injury in whom MI is neither ruled-in nor ruled-out (>1 level ≥15 ng/L, called observation group); follow-up was 5 years.

RESULTS

Of 2738 patients, 547 were in the observation group, of whom 62% were admitted to hospital, 52% to cardiac services, whereas 97% of MI ruled-in patients and 21% of MI ruled-out patients were admitted; P < 0.001. Non-invasive testing occurred in 42% of observation group patients (36% had echo-cardiography), and 16% had coronary angiography. Of observation group patients, MI rates were 1.5% during hospitalisation and 4% during the following year, similar to that in those with MI ruled-in, among those with MI ruled-out, the MI rate was 0.2%. The 1-year death rate was 13% among observation group patients and 11% MI ruled-in patients (P = 0.624), whereas at 5 years among observation group patients, type 1 MI and type 2 MI were 48%, 26% and 58%, respectively (P = 0.001).

CONCLUSION

Very few unselected consecutive patients attending ED, with minor stable HsTnT elevation, had MI, although most had chronic myocardial injury. Late mortality rates among observation group patients were higher than those with confirmed type 1 MI but lower than those with type 2 MI.

Outcomes of European Society of Cardiology 0/1-h algorithm with high-sensitivity cardiac troponin T among patients with coronary artery disease

OBJECTIVE

The European Society of Cardiology (ESC) 0/1-h Algorithm with high-sensitivity cardiac troponin T (hs-cTnT) has shown promising results in risk stratification and management of patients with coronary artery disease (CAD). However, its outcomes and clinical implications in the context of developing countries remain understudied.

METHODS

This cohort study aimed to evaluate the outcomes and clinical significance of the ESC 0/1-h Algorithm in a developing country setting. A total of 3534 patients with CAD were enrolled, with 1125 in the Rule-Out group and 2409 in the Rule-In group. Baseline characteristics, performance metrics, primary and secondary outcomes, and predictors of Rule-In and Rule-Out groups were assessed.

RESULTS

The study enrolled 3534 patients with CAD, with 1125 in the Rule-Out group and 2409 in the Rule-In group. The 0/1-h Algorithm with hs-cTnT demonstrated improved performance compared to Troponin T at Presentation. It exhibited higher sensitivity, specificity, negative predictive value, positive predictive value, and area under the curve (AUC) for risk stratification in patients with CAD. Significant differences were observed in baseline characteristics between the Rule-Out and Rule-In groups, including age, gender, and comorbidities. The Rule-In group had a higher incidence of adverse cardiac events and underwent more invasive procedures compared to the Rule-Out group. Age, gender, hypertension, diabetes, and smoking were identified as significant predictors of Rule-In and Rule-Out. These findings highlight the clinical significance of implementing the 0/1-h Algorithm in the management of patients with CAD in a developing country setting.

CONCLUSION

The algorithm's performance, along with its ability to identify high-risk patients and predict outcomes, highlights its potential to enhance patient care and outcomes in resource-limited settings.

Safety and effectiveness of the short (0-1h) high sensitive troponin protocol in real-life practice

AIM

Recent guidelines recommend the use of a short 0-1h high sensitive cardiac troponin (hs-cTn) algorithm in patients presenting with chest pain at the emergency department (ED). This retrospective observational study evaluates the safety and effectiveness of the new 0-1h hs-cTn I protocol in comparison with the standard 0-3h cTn I protocol for the diagnosis of acute myocardial infarction (AMI).

METHODS

A total of two times 100 consecutive chest pain patients presenting at the ED in November/December 2018 (standard 0-3h cTn I group) and in November/December 2020 (short 0-1h hs-cTn I group) were enrolled. Decision making was based upon validated assay-specific cut-off values.

RESULTS

The new 0-1h hs-cTn I protocol had a sensitivity of 100% (95% CI 83.2-100) and a negative predictive value of 100% to rule out AMI. The accuracy of rule-in was slightly lower with a specificity of 92.5% (95% CI 84.4-97.2). The overall protocol accuracy was 94% (95% CI 87.4-97.8) in the short 0-1h hs-cTn I group compared to 88% (95% CI 80.0-93.6) in the standard 0-3h cTn I group (p-value 0.14). The 0-1h hs-cTn I protocol was associated with a numerically higher rate of early hospital discharge compared to the conventional 0-3h cTn I protocol (47% versus 59%; p-value 0.09) and with a shorter median length of stay for those patients (mean 316 min versus 289 min; p-value 0.09).

CONCLUSION

The abbreviated protocol based on the 0-1h hs-cTn I assays is effective and safe for the exclusion of AMI at the ED.

Use of high-sensitivity cardiac troponin in the emergency department: A policy resource and education paper (PREP) from the American College of Emergency Physicians

This Policy Resource and Education Paper (PREP) from the American College of Emergency Physicians (ACEP) discusses the use of high-sensitivity cardiac troponin (hs-cTn) in the emergency department setting. This brief review discusses types of hs-cTn assays as well as the interpretation of hs-cTn in the setting of various clinical factors such as renal dysfunction, sex, and the important distinction between myocardial injury versus myocardial infarction. In addition, the PREP provides one possible example of an algorithm for the use of a hs-cTn assay in patients in whom the treating clinician is concerned about potential acute coronary syndrome.

Implementation of High-Sensitivity Troponin with a Rapid Diagnostic Algorithm Reduces Emergency Department Length of Stay for Discharged Patients

INTRODUCTION

High sensitivity troponin (hs-cTn) and diagnostic algorithms are used to rapidly triage patients with symptoms of acute myocardial infarction in emergency departments (ED). However, few studies have evaluated the impact of simultaneously implementing hs-cTn and a rapid rule-out algorithm on length of stay (LOS).

METHODS

We assessed the impact of transitioning from contemporary cTnI to hs-cTnI in 59,232 ED encounters over three years. hs-cTnI was implemented with an orderable series that included baseline, two-, four-, and six-hour specimens collected at provider discretion and operationalized with an algorithm to calculate the change in hs-cTnI from baseline and provide interpretations of "insignificant", "significant," or "equivocal." Patient demographics, results, chief complaint, disposition, and ED LOS were captured from the electronic medical record.

RESULTS

cTnI was ordered for 31,875 encounters prior to hs-cTnI implementation and 27,357 after. The proportion of cTnI results above the 99th percentile upper reference limit decreased from 35.0% to 27.0% for men and increased from 27.8% to 34.8% for women. Among discharged patients, the median LOS decreased by 0.6 h (0.5-0.7). LOS among discharged patients with a chief complaint of chest pain decreased by 1.0 h (0.8-1.1) and further decreased by 1.2 h (1.0-1.3) if the initial hs-cTnI was below the limit of quantitation. The rate of acute coronary syndrome upon re-presentation within 30 days did not change post-implementation (0.10% versus 0.07%).

CONCLUSION

Implementation of an hs-cTnI assay with a rapid rule-out algorithm decreased ED LOS among discharged patients, particularly among those with a chief complaint of chest pain.

Serial high-sensitivity cardiac troponin testing for the diagnosis of myocardial infarction: a scoping review

OBJECTIVES

We aimed to assess the diversity and practices of existing studies on several assays and algorithms for serial measurements of high-sensitivity cardiac troponin (hs-cTn) for risk stratification and the diagnosis of myocardial infarction (MI) and 30-day outcomes in patients suspected of having non-ST-segment elevation MI (NSTEMI).

METHODS

We searched multiple databases including MEDLINE, EMBASE, Science Citation Index, the Cochrane Database of Systematic Reviews and the CENTRAL databases for studies published between January 2006 and November 2021. Studies that assessed the diagnostic accuracy of serial hs-cTn testing in patients suspected of having NSTEMI in the emergency department (ED) were eligible. Data were analysed using the scoping review method.

RESULTS

We included 86 publications, mainly from research centres in Europe, North America and Australasia. Two hs-cTn assays, manufactured by Abbott (43/86) and Roche (53/86), dominated the evaluations. The studies most commonly measured the concentrations of hs-cTn at two time points, at presentation and a few hours thereafter, to assess the two-strata or three-strata algorithm for diagnosing or ruling out MI. Although data from 83 studies (97%) were prospectively collected, 0%-90% of the eligible patients were excluded from the analysis due to missing blood samples or the lack of a final diagnosis in 53 studies (62%) that reported relevant data. Only 19 studies (22%) reported on head-to-head comparisons of alternative assays.

CONCLUSION

Evidence on the accuracy of serial hs-cTn testing was largely derived from selected research institutions and relied on two specific assays. The proportions of the eligible patients excluded from the study raise concerns about directly applying the study findings to clinical practice in frontline EDs.

PROSPERO REGISTRATION NUMBER

CRD42018106379.

High-sensitivity troponin I with or without ultra-sensitive copeptin for the instant rule-out of acute myocardial infarction

Background

The instant, single-sampling rule-out of acute myocardial infarction (AMI) is still an unmet clinical need. We aimed at testing and comparing diagnostic performance and prognostic value of two different single-sampling biomarker strategies for the instant rule-out of AMI.

Methods

From the Biomarkers in Acute Cardiac Care (BACC) cohort, we recruited consecutive patients with acute chest pain and suspected AMI presenting to the Emergency Department of the University Medical Center Hamburg-Eppendorf, Hamburg, Germany. We compared safety, effectiveness and 12-month incidence of the composite endpoint of all-cause death and myocardial infarction between (i) a single-sampling, dual-marker pathway combining high-sensitivity cardiac troponin I (hs-cTnI) and ultra-sensitive copeptin (us-Cop) at presentation (hs-cTnI ≤ 27 ng/L, us-Cop < 10 pmol/L and low-risk ECG) and (ii) a single-sampling pathway based on one-off hs-cTnI determination at presentation (hs-cTnI < 5 ng/L and low-risk ECG). As a comparator, we used the European Society of Cardiology (ESC) 0/1-h dual-sampling algorithm.

Results

We enrolled 1,136 patients (male gender 65%) with median age of 64 years (interquartile range, 51–75). Overall, 228 (20%) patients received a final diagnosis of AMI. The two single-sampling instant rule-out pathways yielded similar negative predictive value (NPV): 97.4% (95%CI: 95.4–98.7) and 98.7% (95%CI: 96.9–99.6) for dual-marker and single hs-cTnI algorithms, respectively (P = 0.11). Both strategies were comparably safe as the ESC 0/1-h dual-sampling algorithm and this was consistent across subgroups of early-comers, low-intermediate risk (GRACE-score < 140) and renal dysfunction. Despite a numerically higher rate of false-negative results, the dual-marker strategy ruled-out a slightly but significantly higher percentage of patients compared with single hs-cTnI determination (37.4% versus 32.9%; P < 0.001). There were no significant between-group differences in 12-month composite outcome.

Conclusions

Instant rule-out pathways based on one-off determination of hs-cTnI alone or in combination with us-Cop are comparably safe as the ESC 0/1 h algorithm for the instant rule-out of AMI, yielding similar prognostic information. Instant rule-out strategies are safe alternatives to the ESC 0/1 h algorithm and allow the rapid and effective triage of suspected AMI in patients with low-risk ECG. However, adding copeptin to hs-cTn does not improve the safety of instant rule-out compared with the single rule-out hs-cTn at very low cut-off concentrations.

Point-of-Care: Roadmap for Analytical Characterization and Validation of a High-Sensitivity Cardiac Troponin I Assay in Plasma and Whole Blood Matrices

BACKGROUND

High-sensitivity cardiac troponin (hs-cTn) assays enable more precise use of traditional diagnostic strategies and earlier rule-out/rule-in at 0/1 h or 0/2 h after presentation of acute myocardial infarction (AMI). Availability of hs-cTn measurements at point-of-care (POC) can improve timely management of AMI patients. A roadmap for regulatory and analytical validation is exemplified with studies with the Atellica VTLi hs-cTnI at POC.

METHODS

High-sensitivity performance was assessed with AACC/IFCC expert recommendations. Clinical Laboratory Standards Institute protocols were used for characterizing limit of blank, limit of detection (LoD), limit of quantitation (LoQ), 10% CV, precision, linearity, and analytic specificity with several reagent lots. Bland-Altman, Passing-Bablok, and hematocrit bias plots compared hs-cTnI measurement in lithium-heparin plasma (PL) and whole blood (WB) matrices.

RESULTS

LoB was 0.55 ng/L; LoD and LoQ were 1.24 ng/L and 2.1 ng/Lm for PL and 1.60 ng/L and 3.7 ng/L for WB, respectively. The male 99th percentile is 27 ng/L, and female 99th percentile upper reference limit is 18 ng/L; 10% CVs were 6.7 ng/L for PL and 8.9 ng/L for WB. Also ≥50% of hs-cTnI values for healthy cohorts exceeded the LoD, confirming high-sensitivity performance. Linearity spanned from LoQ to 1250 ng/L. Specificity was >90% for 40 potential interferences; no hook effect was detected. WB and PL correlation was WB = 1.02*plasma + 0.3 ng/L (r = 0.996, n = 152). No hs-cTnI association with hematocrit was detected (R2 = 0.003).

CONCLUSION

This analytical roadmap showed high-sensitivity performance, good analytic characteristics, and excellent PL and WB agreement for the Atellica VTLi hs-cTnI POC system. Essential clinical performance studies in patients by intended POC users may now commence.

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

OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Performance of the 0-Hour/1-Hour Algorithm for Diagnosing Myocardial Infarction in Patients With Chest Pain in the Emergency Department ― A Systematic Review and Meta-Analysis ―

Background: This study assessed the diagnostic performance of the 0-hour/1-hour (0/1-h) algorithm to rule in and rule out acute myocardial infarction (MI) in patients presenting to the emergency department (ED) for suspected acute coronary syndrome without ST-segment elevation, as recommended in the 2015 European Society of Cardiology (ESC) guideline.

Methods and Results: Following the Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy (PRISMA-DTA) guidelines, a systematic review was conducted using the PubMed database from inception to March 31, 2020. We included any article published in English investigating the diagnostic performance of the ESC 0/1-h algorithm for diagnosing MI in patients with chest pain visiting the ED. Of 651 studies identified as potentially available for the study, 7 studies including 16 databases were analyzed. A meta-analysis of the diagnostic accuracy of the 0/1-h algorithm using high-sensitivity cardiac troponin I (hs-cTn) with 6 observational databases showed a pooled sensitivity of 99.3% (95% confidence interval [CI] 98.5–99.7%) and a pooled specificity of 90.1% (95% CI 80.7–95.2%). A meta-analysis of the diagnostic accuracy of 10 observational databases of the ESC 0/1-h algorithm using hs-cTn revealed a pooled sensitivity of 99.3% (95% CI 96.9–99.9%) and a pooled specificity of 91.7% (95% CI 83.5–96.1%).

Conclusions: Our results demonstrate that the ESC 0/1-h algorithm can effectively rule in and rule out patients with non-ST-segment elevation MI.

Implementation of the ESC 0 h/1h algorithm and the HEART score in the emergency department: A prospective cohort study

Background

The European Society of Cardiology (ESC) 0 h/1h algorithm is the preferred diagnostic strategy for chest pain patients in the emergency department (ED). It is suggested that adding clinical information to the algorithm improves its diagnostic performance. This study evaluates implementation of the ESC 0 h/1h algorithm in the ED and investigates the potential advantages of combining it with a clinical decision rule, which might be especially relevant in the heterogenous observation category.

Methods

In this prospective cohort study, chest pain patients in whom the ESC 0 h/1h algorithm was applied were enrolled. HEART score components were collected. Diagnostic characteristics were determined for the algorithm with and without addition of the HEART score. Primary endpoint was a composite endpoint at 30-day follow-up, consisting of myocardial infarction and death.

Results

A total of 668 patients were enrolled. The rule-in and rule-out categories consisted of 8.2% and 54.9% of the patients, respectively. Positive predictive value and specificity of the rule-in category were 67.3% and 97.1%, respectively. Negative predictive value (NPV) and sensitivity of the rule-out category were both 100%. In the observation category, a HEART score ≤ 3 yielded a NPV and sensitivity of 97.1% and 93.8%, respectively.

Conclusion

The ESC 0 h/1h algorithm yielded a NPV and sensitivity of 100% for myocardial infarction and death at 30-day follow-up. Addition of the HEART score did not provide clinically relevant advantages. Although the HEART score can be used to guide diagnostic testing in the observation category, a low HEART score did not yield an NPV of > 99%.

How do we identify acute medical admissions that are suitable for same day emergency care?

Medical emergencies causing unplanned hospital admission place considerable demands on acute healthcare services. Some patients can be assessed and treated through ambulatory pathways without inpatient admission, via same day emergency care (SDEC), potentially benefiting patients and reducing demands on inpatient services. There is currently considerable variation within acute medicine in aspects of SDEC delivery ranging from overall service design to patient selection methods. Scoring systems identifying patients likely to be successfully managed through SDEC services have been suggested, but evidence of utility in diverse populations is lacking. Specific scoring systems exist for some common medical problems, including cardiac chest pain and pulmonary embolism, but further research is needed to demonstrate how these are most effectively incorporated into SDEC services. This review defines SDEC and describes the variation in services nationally. It reviews the evidence for their clinical impact, tools to screen patients for SDEC and current gaps in our knowledge regarding service deployment.

Cost effectiveness of a 1-hour high-sensitivity troponin-T protocol: An analysis of the RAPID-TnT trial

•

This is the first randomised evaluation of the cost-effectiveness of a 0/1-hour high-sensitivity troponin protocol and has implications on clinical practice on a health system level.

•

The results demonstrate that the 0/1-hour hs-cTnT protocol is safe and does not incur excess resource compared to the conventional 0/3-hour protocol.

•

Whilst this cost-effectiveness analysis demonstrates superior ED efficiency and equivalent safety and resource associated with the 0/1-hour hs-cTnT protocol, further refinements in subsequent management is necessary to facilitate large-scale adaptation.

Background

To understand the economic impact of an accelerated 0/1-hour high-sensitivity troponin-T (hs-cTnT) protocol.

Objective

To conduct a patient-level economic analysis of the RAPID-TnT randomised trial in patients presenting with suspected acute coronary syndrome (ACS).

Methods

An economic evaluation was conducted with 3265 patients randomised to either the 0/1-hour hs-cTnT protocol (n = 1634) or the conventional 0/3-hour standard-of-care protocol (n = 1631) with costs reported in Australian dollars. The primary clinical outcome was all-cause mortality or new/recurrent myocardial infarction.

Results

Over 12-months, mean per patient costs were numerically higher in the 0/1-hour arm compared to the conventional 0/3-hour arm (by $472.49/patient, 95% confidence interval [95 %CI]: $-1,380.15 to $2,325.13, P = 0.617) with no statistically significant difference in primary outcome (0/1-hour: 62/1634 [3.8%], 0/3-hour: 82/1631 [5.0%], HR: 1.32 [95 %CI: 0.95–1.83], P = 0.100). The mean emergency department (ED) length of stay (LOS) was significantly lower in the 0/1-hour arm (by 0.62 h/patient, 95 %CI: 0.85 to 0.39, P < 0.001), but the subsequent 12-month unplanned inpatient costs was numerically higher (by $891.22/patient, 95 %CI: $-96.07 to 1,878.50, P = 0.077). Restricting the analysis to patients with hs-cTnT concentrations ≤ 29 ng/L, mean per patient cost remained numerically higher in the 0/1-hour arm (by $152.44/patient, 95 %CI:$-1,793.11 to $2,097.99, P = 0.988), whilst the reduction in ED LOS was more pronounced (by 0.70 h/patient, 95 %CI: 0.45–0.95, P < 0.001).

Conclusions

There were no differences in resource utilization between the 0/1-hour hs-cTnT protocol versus the conventional 0/3-hour protocol for the assessment of suspected ACS, despite improved initial ED efficiency. Further refinements in strategies to improve clinical outcomes and subsequent management efficiency are needed.

Point-of-care testing with high-sensitivity cardiac troponin assays: the challenges and opportunities

Methods to improve the safety, accuracy and efficiency of assessment of patients with suspected acute coronary symptoms have occupied decades of study and have supported significant changes in clinical practice. Much of the progress is reliant on results of laboratory-based high-sensitivity cardiac troponin assays that can detect low concentrations with high precision. Until recently, point-of-care (POC) platforms were unable to perform with similar analytical precision as laboratory-based assays, and recommendations for their use in accelerated assessment strategies for patients with suspected acute coronary syndrome has been limited. As POC assays can provide troponin results within 20 min, and can be used proximate to patient care, improvements in the efficiency of assessment of patients with suspected acute coronary syndrome is possible, particularly with new high-sensitivity assays.

Biomarkers-in-Cardiology 8 RE-VISITED-Consistent Safety of Early Discharge with a Dual Marker Strategy Combining a Normal hs-cTnT with a Normal Copeptin in Low-to-Intermediate Risk Patients with Suspected Acute Coronary Syndrome-A Secondary Analysis of the Randomized Biomarkers-in-Cardiology 8 Trial

Regarding the management of suspected Non-ST-segment-elevation acute coronary syndrome (ACS), the main Biomarker-in-Cardiology (BIC)-8 randomized controlled trial study had reported non-inferiority for the incidence of major adverse cardiac events at 30 days in the Copeptin group (dual marker strategy of copeptin and hs-cTnT at presentation) compared to the standard process (serial hs-cTnT testing). However, in 349 (38.7%) of the 902 patients, high-sensitivity cardiac troponin was not available for the treating physicians. High sensitivity cardiac troponin T was re-measured from thawed blood samples collected at baseline. This cohort qualified for a re-analysis of the 30-day incidence rate of MACE (death, survived cardiac death, acute myocardial infarction, re-hospitalization for acute coronary syndrome, acute unplanned percutaneous coronary intervention, coronary bypass grafting, or documented life-threatening arrhythmias), or components of the primary endpoint including death or death/MI. After re-measurement of troponin and exclusion of 9 patients with insufficient blood sample volume, 893 patients qualified for re-analysis. A total of 57 cases were detected with high sensitivity cardiac troponin T ≥ 14 ng/L who had been classified as “troponin negative” based on a conventional cardiac troponin T or I < 99th percentile upper limit of normal. Major adverse cardiac events rates after exclusion were non-inferior in the Copeptin group compared to the standard group (4.34% (95% confidence intervals 2.60–6.78%) vs. 4.27% (2.55–6.66%)). Rates were 53% lower in the per-protocol analysis (HR 0.47, 95% CI: 0.18–1.15, p = 0.09). No deaths occurred within 30 days in the discharged low risk patients of the Copeptin group. Copeptin combined with high sensitivity cardiac troponin is useful for risk stratification and allows early discharge of low-to-intermediate risk patients with suspected acute coronary syndrome is as safe as a re-testing strategy at 3 h or later.

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

BACKGROUND

The 2020 European Society of Cardiology (ESC) guidelines recommend using the 0/1-hour and 0/2-hour algorithms over the 0/3-hour algorithm as the first and second choices of high-sensitivity cardiac troponin (hs-cTn)-based strategies for triage of patients with suspected acute myocardial infarction (AMI).

PURPOSE

To evaluate the diagnostic accuracies of the ESC 0/1-hour, 0/2-hour, and 0/3-hour algorithms.

DATA SOURCES

PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus from 1 January 2011 to 31 December 2020. (PROSPERO: CRD42020216479).

STUDY SELECTION

Prospective studies that evaluated the ESC 0/1-hour, 0/2-hour, or 0/3-hour algorithms in adult patients presenting with suspected AMI.

DATA EXTRACTION

The primary outcome was index AMI. Twenty unique cohorts were identified. Primary data were obtained from investigators of 16 cohorts and aggregate data were extracted from 4 cohorts. Two independent authors assessed each study for methodological quality.

DATA SYNTHESIS

A total of 32 studies (20 cohorts) with 30 066 patients were analyzed. The 0/1-hour algorithm had a pooled sensitivity of 99.1% (95% CI, 98.5% to 99.5%) and negative predictive value (NPV) of 99.8% (CI, 99.6% to 99.9%) for ruling out AMI. The 0/2-hour algorithm had a pooled sensitivity of 98.6% (CI, 97.2% to 99.3%) and NPV of 99.6% (CI, 99.4% to 99.8%). The 0/3-hour algorithm had a pooled sensitivity of 93.7% (CI, 87.4% to 97.0%) and NPV of 98.7% (CI, 97.7% to 99.3%). Sensitivity of the 0/3-hour algorithm was attenuated in studies that did not use clinical criteria (GRACE score <140 and pain-free) compared with studies that used clinical criteria (90.2% [CI, 82.9 to 94.6] vs. 98.4% [CI, 88.6 to 99.8]). All 3 algorithms had similar specificities and positive predictive values for ruling in AMI, but heterogeneity across studies was substantial. Diagnostic performance was similar across the hs-cTnT (Elecsys; Roche), hs-cTnI (Architect; Abbott), and hs-cTnI (Centaur/Atellica; Siemens) assays.

LIMITATION

Diagnostic accuracy, inclusion and exclusion criteria, and cardiac troponin sampling time varied among studies.

CONCLUSION

The ESC 0/1-hour and 0/2-hour algorithms have higher sensitivities and NPVs than the 0/3-hour algorithm for index AMI.

PRIMARY FUNDING SOURCE

National Taiwan University Hospital.

Rapid Rule-Out of Myocardial Infarction After 30 Minutes as an Alternative to 1 Hour: The RACING-MI Cohort Study

STUDY OBJECTIVE

The aim of this study was to investigate whether myocardial infarction can be safely ruled in or out after 30 minutes as an alternative to 1 hour.

METHODS

This was a prospective, single-center clinical study enrolling patients admitted to the emergency department. Patients with chest pain suggestive of myocardial infarction were eligible for inclusion. There was no walk-in to the emergency department, and patients with highly elevated out-of-hospital troponin were transferred directly to an invasive heart center. High-sensitivity troponin I was measured at admission (0 hour), 30 minutes, 1 hour, and 3 hours. Diagnostic performance was assessed using the sensitivity and negative predictive value (primary endpoints) as measures of ability to rule out myocardial infarction. Specificity and positive predictive value of myocardial infarction were used as measures for the ability to rule in myocardial infarction (secondary endpoints).

RESULTS

In total, 1,003 patients qualified for analysis. Median age was 64 (interquartile range 52 to 74) years, and 42% were women. Myocardial infarction was confirmed in 9% of patients. In the validation cohort (n=503), the 0-h/30-min algorithm assigned 242 (48%) patients to rule out, 54 (11%) to rule in, and 207 (41%) to the observational zone. This resulted in a sensitivity of 100% (92.0% to 100%), negative predictive value of 100% (95% confidence interval 98.5% to 100%), specificity of 96.7% (94.7% to 98.2%), and positive predictive value of 72.2% (58.4% to 83.5%). In comparison, the 0-h/1-h algorithm performed with a sensitivity of 100% (92.0% to 100%), negative predictive value of 100% (98.5% to 100%), specificity of 97.2% (95.2% to 98.5%), and positive predictive value of 75.5% (61.7% to 86.2%).

CONCLUSION

The accelerated 0-h/30-min algorithm allowed for safe rule-out of myocardial infarction 30 minutes after admission. The rule-in ability of the 0-h/30-min algorithm was comparable to that of the 0-h/1h algorithm.

External validation of a high-sensitive troponin I algorithm for rapid evaluation of acute myocardial infarction in a Danish cohort

AIMS

An accelerated diagnostic algorithm for ruling-in or ruling-out myocardial infarction (MI) after 1 hour (1 h) has recently been derived and internally validated for the Siemens ADVIA Centaur TNIH assay. We aimed to validate the diagnostic performance of the TNIH 0 h/1 h algorithm ad modum Boeddinghaus in a Danish cohort.

METHODS AND RESULTS

Patients with chest pain suggestive of MI were prospectively enrolled. High-sensitive troponin I (TNIH) was measured at admission (0 h) and after 30 minutes (30 m), 1 h, and 3 hours (3 h). We externally validated the TNIH 0 h/1 h algorithm ad modum Boeddinghaus in Danish patients. Moreover, we applied the algorithm using the second TNIH measurement at 30 m instead of 1 h. We enrolled 1003 patients: median (Q1-Q3) age 64 (52-74) years, 42% female, and 23% with previous MI. Myocardial infarction was the final diagnosis in 9% of patients. Median (Q1-Q3) times from admission to 30 m and 1 h blood draw were 35 min (30-37 min) and 67 min (62-75 min), respectively. Using the 0 h and 1 h results, 468 (47%) patients were assigned to rule-out, 104 (10%) to rule-in, and 431 (43%) to the observational zone. This resulted in a negative predictive value of 100% (95% confidence interval: 99.2-100%), sensitivity of 100% (95.9-100%), positive predictive value of 79.8 (70.8-87.0%), and specificity of 97.7% (96.5-98.6%). The diagnostic performance after 30 m was similar.

CONCLUSIONS

The TNIH 0 h/1 h algorithm ad modum Boeddinghaus performed excellently for rule-out of MI in a Danish cohort. The Boeddinghaus algorithm also performed excellently after only 30 m.

TRIAL REGISTRATION NUMBER

NCT03634384.

TRIAL REGISTRY NAME AND URL

Rapid Use of High-Sensitive Cardiac Troponin I for Ruling-in and Ruling-out Acute Myocardial Infarction (RACING-MI), https://clinicaltrials.gov/ct2/show/NCT03634384.

Cardiac Troponin Thresholds and Kinetics to Differentiate Myocardial Injury and Myocardial Infarction

BACKGROUND

Although the 99th percentile is the recommended diagnostic threshold for myocardial infarction, some guidelines also advocate the use of higher troponin thresholds to rule in myocardial infarction at presentation. It is unclear whether the magnitude or change in troponin concentration can differentiate causes of myocardial injury and infarction in practice.

METHODS

In a secondary analysis of a multicenter randomized controlled trial, we identified 46 092 consecutive patients presenting with suspected acute coronary syndrome without ST-segment-elevation myocardial infarction. High-sensitivity cardiac troponin I concentrations at presentation and on serial testing were compared between patients with myocardial injury and infarction. The positive predictive value and specificity were determined at the sex-specific 99th percentile upper reference limit and rule-in thresholds of 64 ng/L and 5-fold of the upper reference limit for a diagnosis of type 1 myocardial infarction.

RESULTS

Troponin was above the 99th percentile in 8188 patients (18%). The diagnosis was type 1 or type 2 myocardial infarction in 50% and 14% and acute or chronic myocardial injury in 20% and 16%, respectively. Troponin concentrations were similar at presentation in type 1 (median [25th-75th percentile] 91 [30-493] ng/L) and type 2 (50 [22-147] ng/L) myocardial infarction and in acute (50 [26-134] ng/L) and chronic (51 [31-130] ng/L) myocardial injury. The 99th percentile and rule-in thresholds of 64 ng/L and 5-fold upper reference limit gave a positive predictive value of 57% (95% CI, 56%-58%), 59% (58%-61%), and 62% (60%-64%) and a specificity of 96% (96%-96%), 96% (96%-96%), and 98% (97%-98%), respectively. The absolute, relative, and rate of change in troponin concentration were highest in patients with type 1 myocardial infarction (P<0.001 for all). Discrimination improved when troponin concentration and change in troponin were combined compared with troponin concentration at presentation alone (area under the curve, 0.661 [0.642-0.680] versus 0.613 [0.594-0.633]).

CONCLUSIONS

Although we observed important differences in the kinetics, cardiac troponin concentrations at presentation are insufficient to distinguish type 1 myocardial infarction from other causes of myocardial injury or infarction in practice and should not guide management decisions in isolation. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01852123.

Critical appraisal of the 2020 ESC guideline recommendations on diagnosis and risk assessment in patients with suspected non-ST-segment elevation acute coronary syndrome

Multiple new recommendations have been introduced in the 2020 ESC guidelines for the management of acute coronary syndromes with a focus on diagnosis, prognosis, and management of patients presenting without persistent ST-segment elevation. Most recommendations are supported by high-quality scientific evidence. The guidelines provide solutions to overcome obstacles presumed to complicate a convenient interpretation of troponin results such as age-, or sex-specific cutoffs, and to give practical advice to overcome delays of laboratory reporting. However, in some areas, scientific support is less well documented or even missing, and other areas are covered rather by expert opinion or subjective recommendations. We aim to provide a critical appraisal on several recommendations, mainly related to the diagnostic and prognostic assessment, highlighting the discrepancies between Guideline recommendations and the existing scientific evidence.

A Practical Approach for the Use of High-Sensitivity Cardiac Troponin Assays in the Evaluation of Patients With Chest Pain

Chest pain is a common clinical presentation, especially in the emergency department. Both rapid identification of patients with myocardial infarction as well as those with noncardiac chest pain is important in order to start therapy in the former and avoid unnecessary investigations and delay in discharge in the latter. Beside electrocardiogram, cardiac biomarkers are a key element in decision making. Conventional creatinine kinase and troponin assays are not sensitive enough and have to be repeated at least 6 to 12 hours after initial evaluation. New high-sensitivity cardiac troponin (hs-cTn) tests are currently available and if used appropriately can substantially improve management. Because of their high sensitivity and accuracy, these tests allow measurement of very low serum troponin levels, such as those present in healthy individuals and can detect small changes in troponin concentration within a short time frame. These tests are thus, very useful for the early diagnosis of myocardial infarction but can also be elevated in several other conditions that result in myocardial injury. A good understanding of the analytical characteristics of these assays is of uppermost importance for their appropriate use in clinical practice.