Economic evaluation of the one-hour rule-out and rule-in algorithm for acute myocardial infarction using the high-sensitivity cardiac troponin T assay in the emergency department

Improved Utilization of Serial Testing Without Increased Admissions after Implementation of High-Sensitivity Troponin I: a Controlled Retrospective Cohort Study

BACKGROUND

Guidelines recommend high-sensitivity cardiac troponin (hs-cTn) for diagnosis of myocardial infarction. Use of hs-cTn is increasing across the U.S., but questions remain regarding clinical and operational impact. Prior studies have had methodologic limitations and yielded conflicting results.

OBJECTIVE

To evaluate the impact of transitioning from conventional cardiac troponin (cTn) to hs-cTn on test and resource utilization, operational efficiency, and patient safety.

DESIGN

Retrospective cohort study in two New York City hospitals during the months before and after transition from conventional cTn to hs-cTn at Hospital 1. Hospital 2 served as a control.

PARTICIPANTS

Consecutive emergency department (ED) patients with at least one cTn test resulted.

INTERVENTION

Multifaceted hs-cTn intervention bundle, including a 0/2-h diagnostic algorithm for non-ST-elevation myocardial infarction, an educational bundle, enhancements to the electronic medical record, and nursing interventions to facilitate timed sample collection.

MAIN MEASURES

Primary outcomes included serial cTn test utilization, probability of hospital admission, ED length of stay (LOS), and among discharged patients, probability of ED revisit within 72 h resulting in hospital admission. Multivariable regression models adjusted for age, sex, temporal trends, and interhospital differences.

KEY RESULTS

The intervention was associated with increased use of serial cTn testing (adjusted risk difference: 48 percentage points, 95% CI: 45-50, P < 0.001) and ED LOS (adjusted geometric mean difference: 50 min, 95% CI: 50-51, P < 0.001). There was no significant association between the intervention and probability of admission (adjusted relative risk [aRR]: 0.99, 95% CI: 0.89-1.1, P = 0.81) or probability of ED revisit within 72 h resulting in admission (aRR: 1.1, 95% CI: 0.44-2.9, P = 0.81).

CONCLUSIONS

Implementation of a hs-cTn intervention bundle was associated with an improvement in serial cTn testing, a neutral effect on probability of hospital admission, and a modest increase in ED LOS.

Is rapid acute coronary syndrome evaluation with high-sensitivity cardiac troponin less costly? An economic evaluation

Objective

Protocols to evaluate for myocardial infarction (MI) using high-sensitivity cardiac troponin (hs-cTn) have the potential to drive costs upward due to the added sensitivity. We performed an economic evaluation of an accelerated protocol (AP) to evaluate for MI using hs-cTn to identify changes in costs of treatment and length of stay compared with conventional testing.

Methods

We performed a planned secondary economic analysis of a large, cluster randomized trial across nine emergency departments (EDs) from July 2020 to April 2021. Patients were included if they were 18 years or older with clinical suspicion for MI. In the AP, patients could be discharged without further testing at 0 h if they had a hs-cTnI < 4 ng/L and at 1 h if the initial value were 4 ng/L and the 1-h value ≤7 ng/L. Patients in the standard of care (SC) protocol used conventional cTn testing at 0 and 3 h. The primary outcome was the total cost of treatment, and the secondary outcome was ED length of stay.

Results

Among 32,450 included patients, an AP had no significant differences in cost (+$89, CI: -$714, $893 hospital cost, +$362, CI: -$414, $1138 health system cost) or ED length of stay (+46, CI: -28, 120 min) compared with the SC protocol. In lower acuity, free-standing EDs, patients under the AP experienced shorter length of stay (-37 min, CI: -62, 12 min) and reduced health system cost (-$112, CI: -$250, $25).

Conclusion

Overall, the implementation of AP using hs-cTn does not result in higher costs.

Analytical assays and bootstrap resampling method to validate performance of the Roche Elecsys STAT highly sensitive troponin T assay and its application for the 'rule-out' part of ESC guidelines for NTSTEMI

BACKGROUND

The European Society of Cardiology (ESC) guidelines recommend a dynamic (0-1h) cardiac troponin (cTn) determination for non-ST elevation myocardial infarction diagnosis. For patients with low cTn levels, a discharge from emergency can be considered. Nevertheless, cTn cutoffs for discharge are lower than the limits of quantification proposed by laboratory reagent suppliers.

AIM

Validate cTn assay on the Elecsys STAT kit.

MATERIALS AND METHODS

Precision, trueness, repeatability and within-laboratory variability were calculated from internal quality control and plasma pooled at 5.78 and 10.73 ng/L. Accuracy was calculated from external quality control. Uncertainty of measurement was calculated from (i) the uncertainty of the standard and control values and (ii) by precision from pooled plasma. Distribution of precision results from pooled plasma has been evaluated by bootstrap simulations. Dilution linearity tests with patient plasma were performed to evaluate the method for values near 5 ng/L.

RESULTS

Precision and trueness ranged from 1.35 to 4.45% and from 0.14 to -3.74%, respectively. Accuracy results ranged from 101.40 to 104.90%. Within laboratory variability was 2.91%. Uncertainty ranged from 3.66% to 19.90% for higher (2188) to lower values (5.78 ng/L). Bootstrap simulations allowed utilization of precision data from pooled plasma to evaluate cTn assay. The method was linear from 4.48 to 39.80 ng/L. A linear regression model best described the data.

CONCLUSION

Elecsys STAT method provides accurate cTn results, including patients with cTn results categorizing them as 'rule-out' in the ESC guidelines.

Diagnostic and Cost Efficiency of the 0-h/1-h Rule-out and Rule-in Algorithm for Patients With Chest Pain in the Emergency Department

BACKGROUND

This study investigated the economic impact of the European Society of Cardiology (ESC) clinical practice guideline recommendation of using the 0-h/1-h rule-out and rule-in algorithm with high-sensitivity cardiac troponin assays (0/1-h algorithm) to triage patients presenting with chest pain.

METHODS AND RESULTS

This post hoc cost-effectiveness evaluation (DROP-ACS; UMIN000030668) used deidentified electronic medical records from health insurance claims from 2 diagnostic centers in Japan. A cost-effectiveness analysis was conducted with 472 patients with care provided following the 0/1-h algorithm (Hospital A) and 427 patients following point-of-care testing (Hospital B). The clinical outcome of interest was all-cause mortality or subsequent myocardial infarction within 30 days of the index presentation. The sensitivity and specificity for the clinical outcome were 100% (95% confidence interval [CI] 91.1-100%) and 95.0% (95% CI 94.3-95.0%), respectively, in Hospital A and 92.9% (95% CI 69.6-98.7%) and 89.8% (95% CI 89.0-90.0%), respectively, in Hospital B. If the diagnostic accuracy of the 0/1-h algorithm was implemented in Hospital B, it is expected that the number of urgent (<24-h) coronary angiograms would decrease by 50%. Incorporating this assumption, implementing the 0/1-h algorithm could potentially reduce medical costs by JPY4,033,874 (95% CI JPY3,440,346-4,627,402) in Hospital B (JPY9,447 per patient; 95% CI JPY 8,057-10,837 per patient).

CONCLUSIONS

The ESC 0/1-h algorithm was efficient for risk stratification and for reducing medical costs.

Real-World Evidence on Disparities on the Initiation of Ticagrelor Versus Prasugrel in Patients With Acute Coronary Syndrome

Background Management of patients with non-ST-segment-elevation acute coronary syndrome (NSTE-ACS) is based on 2020 European Society of Cardiology guidelines, which recommend the preferential use of prasugrel over ticagrelor. Because the selection of the respective P2Y12 inhibitor has to consider label restrictions, we sought to evaluate the proportion of patients qualifying for either ticagrelor or prasugrel and reasons for noneligibility in an unselected cohort of patients with acute coronary syndrome. Methods and Results In this retrospective observational study, patients with ST-segment-elevation myocardial infarction (STEMI) or NSTE-ACS presenting consecutively during a 24-month period were enrolled. The eligibility of patients for a dual antiplatelet therapy option was assessed retrospectively. A total of 1502 patients had confirmed acute coronary syndrome (287 STEMI and 1215 NSTE-ACS). Eligibility for ticagrelor and full-dose prasugrel differed significantly for STEMI and NSTE-ACS (93% versus 51%, P<0.0001 versus 80% versus 31%, P<0.0001). Eligibility remained significantly lower (STEMI 78% versus NSTE-ACS 52%) if low-dose prasugrel was considered. Patients eligible for full-dose prasugrel had lower ischemic risk per GRACE (Global Registry of Acute Coronary Events) score (109 points [90-129 points] versus 121 points [98-146 points], P<0.0001) and lower bleeding risk (14 points [13-15 points] versus 20 points [12-29 points], P<0.0001) per PRECISE-DAPT (Predicting Bleeding Complications in Patients Undergoing Stent Implantation and Subsequent Dual Antiplatelet Therapy) score. Conclusions In real life, eligibility for prasugrel in patients requiring dual antiplatelet therapy is considerably lower than for ticagrelor, even in a cohort with high rates of coronary angiography and percutaneous coronary interventions. The recommended use of prasugrel over ticagrelor in current acute coronary syndrome guidelines contrasts with our observations of a substantial disparity on the eligibility. This important aspect has not received appropriate attention yet. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT05774431.

Evaluation of the Practice Guideline Used for Rule-Out of Myocardial Infarction at a Tertiary Cardiology Center

INTRODUCTION

With the current high burden on the healthcare system and limited resources, the efficient utilization of facilities is of utmost importance. We sought to present the practice guideline used at a high prevalence tertiary cardiology center and compare its safety and efficacy performance with the single high-sensitivity cardiac troponin T strategy, conventional and modified HEART score.

METHODS

In this prospective cohort study, consecutive patients presenting to the emergency department with chest pain or an angina equivalent were recruited. The primary endpoints consisted of major adverse cardiac events at index visits and 30-day follow-up. Patients were managed according to the practice guideline, and sensitivity and negative predictive values were compared.

RESULTS

Of the total 1548 patients, the mean age was 50.4 ± 15.7 years. Ninety-nine (10.9%) patients were admitted at the index visit, and 89 patients were consequently diagnosed with acute coronary symptoms. Six (0.007%) patients experienced major adverse cardiac events within the 30-day follow-up among discharged patients. Among 911 patients with at least 1 troponin, using single high-sensitivity cardiac troponin T, HEART score, and modified HEART score would have further admitted 805, 450, and 609 patients, respectively. The negative predictive value for all 4 algorithms did not significantly differ (99.2% vs. 100% vs. 99.3% vs. 99.6%, respectively).

CONCLUSIONS

The Tehran Herat Center protocol was a relatively safe protocol with high efficacy. Despite the high safety of the other diagnostic pathways, the high volume of patients needing additional evaluation could impose a high burden on the health care system.

Advantage of Using of High-Sensitivity Troponin I Compared to Conventional Troponin I in Shortening Time to Rule out/in Acute Coronary Syndrome in Chest Pain Patients Presenting to the Emergency Department

Background and Objectives: We aimed to compare the time to diagnosis for acute coronary syndromes using high-sensitivity troponin I (hsTnI) and conventional troponin I (TnI) in patients presenting to the emergency department (ED) with chest pain. Materials and Methods: This was an observational prospective study involving patients presenting to the ED of Sant’Andrea Hospital University la Sapienza in Rome (Italy) with chest pain from January to December 2014. Serum troponin was drawn at presentation, and at 3, 6, 9, and/or 12 h if clinically indicated. Depending on date of recruitment, patients had either hsTnI (Abbott Laboratories) or TnI (Abbott Laboratories) performed. The primary endpoint was the time to diagnosis at index visit. Results: A total of 1059 patients were recruited, (673 [63.6%] male, median age 60 years [interquartile range 49−73 years]), out of whom 898 (84.8%) patients were evaluated with hsTnI and 161 (15.2%) with TnI. A total of 393 (37.1%) patients had the diagnosis of acute coronary syndrome in ED. The median time to diagnosis for those evaluated with TnI was 400 min, IQR 120−720 min, while the use of hsTnI led to a significantly shorter time to diagnosis (median 200 min, IQR 100−200 min, p < 0.001). Conclusions: This study confirms that in patients presenting to the emergency department with chest pain, the use of hsTnI is associated with a reduced time to ruling in/out ACS, and, consequently, hsTnI should be routinely used over TnI for more rapid identification of ACS with benefits for patients and related costs.

A 0/1h-algorithm using cardiac myosin-binding protein C for early diagnosis of myocardial infarction

AIMS

Cardiac myosin-binding protein C (cMyC) demonstrated high diagnostic accuracy for the early detection of non-ST-elevation myocardial infarction (NSTEMI). Its dynamic release kinetics may enable a 0/1h-decision algorithm that is even more effective than the ESC hs-cTnT/I 0/1 h rule-in/rule-out algorithm.

METHODS AND RESULTS

In a prospective international diagnostic study enrolling patients presenting with suspected NSTEMI to the emergency department, cMyC was measured at presentation and after 1 h in a blinded fashion. Modelled on the ESC hs-cTnT/I 0/1h-algorithms, we derived a 0/1h-cMyC-algorithm. Final diagnosis of NSTEMI was centrally adjudicated according to the 4th Universal Definition of Myocardial Infarction. Among 1495 patients, the prevalence of NSTEMI was 17%. The optimal derived 0/1h-algorithm ruled-out NSTEMI with cMyC 0 h concentration below 10 ng/L (irrespective of chest pain onset) or 0 h cMyC concentrations below 18 ng/L and 0/1 h increase <4 ng/L. Rule-in occurred with 0 h cMyC concentrations of at least 140 ng/L or 0/1 h increase ≥15 ng/L. In the validation cohort (n = 663), the 0/1h-cMyC-algorithm classified 347 patients (52.3%) as 'rule-out', 122 (18.4%) as 'rule-in', and 194 (29.3%) as 'observe'. Negative predictive value for NSTEMI was 99.6% [95% confidence interval (CI) 98.9-100%]; positive predictive value 71.1% (95% CI 63.1-79%). Direct comparison with the ESC hs-cTnT/I 0/1h-algorithms demonstrated comparable safety and even higher triage efficacy using the 0h-sample alone (48.1% vs. 21.2% for ESC hs-cTnT-0/1 h and 29.9% for ESC hs-cTnI-0/1 h; P < 0.001).

CONCLUSION

The cMyC 0/1h-algorithm provided excellent safety and identified a greater proportion of patients suitable for direct rule-out or rule-in based on a single measurement than the ESC 0/1h-algorithm using hs-cTnT/I.

TRIAL REGISTRATION

ClinicalTrials.gov number, NCT00470587.

Evaluation of a cardiac troponin process flow at the chest pain center with the shortest turnaround time

BACKGROUND

Early diagnosis of myocardial infarction is crucial in chest pain management and cardiac troponin (cTn) test is an important step in it. Process improvement to shorten the test turnaround time (TAT) may improve patients' outcomes. The cTn test at chest pain center (CPC) of Zhongshan Hospital had the shortest TAT ever reported, but its process flow was not fully evaluated.

METHODS

We performed a stepwise evaluation of CPC cTn TAT and explored the potential factor that might cause delay. The performance of CPC cTn test was also compared with cTn test and human chorionic gonadotropin (HCG) test ordered from emergency department (ED).

RESULTS

At least 95% of CPC cTn tests were completed in 60 min, while 62% in 30 min. The medians of monthly order-to-collect time, collect-to-received time, and received-to-result time were ~7 min, ~3 min, and ~13 min, respectively. The samples collected at the bedside had longer collect-to-received time than the ones collected at the blood draw site next to the laboratory. Compared to ED cTn test and ED HCG test, CPC cTn test took less time in each step. A combination of the sample type switch and the centrifugation time reduction contributed the most to the shortening of TAT, which was reflected in the received-to-result time.

CONCLUSIONS

The current process flow of CPC cTn test satisfied the requirements of chest pain management, giving an example of how to implement process improvement for emergency medicine to shorten TAT of laboratory tests.

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.

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.

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.

Downstream Cascades of Care Following High-Sensitivity Troponin Test Implementation

BACKGROUND

Patients with chest pain are often evaluated for acute myocardial infarction through troponin testing, which may prompt downstream services (cascades) of uncertain value.

OBJECTIVES

This study sought to determine the association of high-sensitivity cardiac troponin (hs-cTn) assay implementation with cascade events.

METHODS

Using electronic health record and billing data, this study examined patient-visits to 5 emergency departments from April 1, 2017, to April 1, 2019. Difference-in-differences analysis compared patient-visits for chest pain (n = 7,564) to patient-visits for other symptoms (n = 100,415) (irrespective of troponin testing) before and after hs-cTn assay implementation. Outcomes included presence of any cascade event potentially associated with an initial hs-cTn test (primary), individual cascade events, length of stay, and spending on cardiac services.

RESULTS

Following hs-cTn implementation, patients with chest pain had a 2.8% (95% confidence interval [CI]: 0.72% to 4.9%) net increase in experiencing any cascade event. They were more likely to have multiple troponin tests (10.5%; 95% CI: 9.0% to 12.0%) and electrocardiograms (7.1 per 100 patient-visits; 95% CI: 1.8 to 12.4). However, they received net fewer computed tomography scans (-1.5 per 100 patient-visits; 95% CI: -1.8 to -1.1), stress tests (-5.9 per 100 patient-visits; 95% CI: -6.5 to -5.3), and percutaneous coronary intervention (PCI) (-0.65 per 100 patient-visits; 95% CI: -1.01 to -0.30) and were less likely to receive cardiac medications, undergo cardiology evaluation (-3.5%; 95% CI: -4.5% to 2.6%), or be hospitalized (-5.8%; 95% CI: -7.7% to -3.8%). Patients with chest pain had lower net mean length of stay (-0.24 days; 95% CI: -0.32 to -0.16) but no net change in spending.

CONCLUSIONS

Hs-cTn assay implementation was associated with more net upfront tests yet fewer net stress tests, PCI, cardiology evaluations, and hospital admissions in patients with chest pain relative to patients with other symptoms.

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.

Development, validation, and implementation of biomarker testing in cardiovascular medicine state-of-the-art: proceedings of the European Society of Cardiology-Cardiovascular Round Table

Many biomarkers that could be used to assess ejection fraction, heart failure, or myocardial infarction fail to translate into clinical practice because they lack essential performance characteristics or fail to meet regulatory standards for approval. Despite their potential, new technologies have added to the complexities of successful translation into clinical practice. Biomarker discovery and implementation require a standardized approach that includes: identification of a clinical need; identification of a valid surrogate biomarker; stepwise assay refinement, demonstration of superiority over current standard-of-care; development and understanding of a clinical pathway; and demonstration of real-world performance. Successful biomarkers should improve efficacy or safety of treatment, while being practical at a realistic cost. Everyone involved in cardiovascular healthcare, including researchers, clinicians, and industry partners, are important stakeholders in facilitating the development and implementation of biomarkers. This article provides suggestions for a development pathway for new biomarkers, discusses regulatory issues and challenges, and suggestions for accelerating the pathway to improve patient outcomes. Real-life examples of successful biomarkers-high-sensitivity cardiac troponin, T2* cardiovascular magnetic resonance imaging, and echocardiography-are used to illustrate the value of a standardized development pathway in the translation of concepts into routine clinical practice.

Diagnostic Reclassification by a High-Sensitivity Cardiac Troponin Assay

STUDY OBJECTIVE

Our objective is to describe the rates of diagnostic reclassification between conventional cardiac troponin I (cTnI) and high-sensitivity cardiac troponin T (hs-cTnT) and between combined and sex-specific hs-cTnT thresholds in adult emergency department (ED) patients in the United States.

METHODS

We conducted a prospective, single-center, before-and-after, observational study of ED patients aged 18 years or older undergoing single or serial cardiac troponin testing in the ED for any reason before and after hs-cTnT implementation. Conventional cTnI and hs-cTnT results were obtained from a laboratory quality assurance database. Combined and sex-specific thresholds were the published 99th percentile upper reference limits for each assay. Cases underwent physician adjudication using the Fourth Universal Definition of Myocardial Infarction. Diagnostic reclassification occurred when a patient received a diagnosis of myocardial infarction or myocardial injury with one assay but not the other assay. Our primary outcome was diagnostic reclassification between the conventional cTnI and hs-cTnT assays. Diagnostic reclassification probabilities were assessed with sample proportions and 95% confidence intervals for binomial data.

RESULTS

We studied 1,016 patients (506 men [50%]; median age 60 years [25th, 75th percentiles 49, 71]). Between the conventional cTnI and hs-cTnT assays, 6 patients (0.6%; 95% confidence interval 0.2% to 1.3%) underwent diagnostic reclassification regarding myocardial infarction (5/6 reclassified as no myocardial infarction) and 166 patients (16%; 95% confidence interval 14% to 19%) underwent diagnostic reclassification regarding myocardial injury (154/166 reclassified as having myocardial injury) by hs-cTnT.

CONCLUSION

Compared with conventional cTnI, the hs-cTnT assay resulted in no clinically relevant change in myocardial infarction diagnoses but substantially more myocardial injury diagnoses.

High-sensitivity methods for cardiac troponins: The mission is not over yet

The measurement of cardiac troponin (cTn) is recommended by all guidelines as the gold standard for the differential diagnosis of Acute Coronary Syndromes. The aim of this review is to discuss in details some key issues regarding both analytical and clinical characteristics of the high-sensitivity methods for cTn (hs-cTn), which are still considered controversial or unresolved. In particular, the major clinical concern regarding hs-cTn methods is the difficulty to differentiate the pathophysiological mechanism responsible for biomarker release from cardiomyocytes after reversible or irreversible injury, respectively. Indeed, recent experimental and clinical studies have demonstrated that different circulating forms of cTnI and cTnT can be respectively measured in plasma samples of patients with reversible or irreversible myocardial injury. Accordingly, a new generation of hs-Tn methods should be set up, based on immunometric immunoassays or chromatographic techniques, specific for circulating peptide forms more characteristics for reversible or irreversible myocardial injury. It is conceivable that this new generation of hs-cTn methods will complete the mission regarding the laboratory tests for specific cardiac biomarkers, started more than 20 years ago, which has already revolutionized the diagnosis, prognosis and management of patients with cardiac diseases.

Effects of crowding in the emergency department on the diagnosis and management of suspected acute coronary syndrome using rapid algorithms: an observational study

OBJECTIVES

Fast diagnostic algorithms using high-sensitivity troponin (hsTn) in suspected acute coronary syndrome (ACS) are regarded as beneficial to expedite diagnosis and safe discharge of patients in crowded emergency departments (ED). This study investigates the effects of crowding on process times related to the diagnostic protocol itself or other time delays, and outcomes.

DESIGN

Prospective single-centre observational study.

SETTING

ED (Germany).

PARTICIPANTS

Final study population of 2525 consecutive patients with suspected ACS within 12 months, after exclusion of patients with ST-elevation myocardial infarction, missing blood samples, referral from other hospitals or repeated visits.

INTERVENTIONS

Use of fast algorithms as per 2015 European Society of Cardiology guidelines.

MAIN OUTCOME MEASURES

Crowding was defined as mismatch between patient numbers and monitoring capacities, or mean physician time per case, categorised as normal, high and very high crowding. Outcome measures were length of ED stay, direct discharge from ED, laboratory turn around times (TAT), utilisation of fast algorithms, absolute and relative non-laboratory time, as well as mortality.

RESULTS

Crowding was associated with increased length of ED stay (3.75-4.89 hours, p<0.001). While median TAT of the first hsTnT increased (53-57 min, p<0.001), total TAT of serial hsTnT did not increase significantly with higher crowding (p=0.170). Lower utilisation of fast algorithms (p=0.009) and increase of additional hsTnT measurements after diagnosis (p=0.001) were observed in higher crowding. Most importantly, crowding was significantly associated with prolonged absolute (p<0.001), and particularly relative non-laboratory time (63.3%-71.3%, p<0.001). However, there was no significant effect of crowding on mortality, even after adjustment for relevant clinical variables.

CONCLUSIONS

Process times, and particularly non-laboratory times, are prolonged in a crowded ED diminishing some positive effects of fast diagnostic algorithms in suspected ACS. Higher crowding levels were not significantly associated with higher all-cause mortality rates.

TRIAL REGISTRATION NUMBER

NCT03111862.

Recent developments in diagnosis and risk stratification of non-ST-elevation acute coronary syndrome

In the past year, a number of important papers have been published on non-ST-elevation acute coronary syndrome, highlighting progress in clinical care. The current review focuses on early diagnosis and risk stratification using biomarkers and advances in intracoronary imaging.

Evaluating the Diagnostic and Prognostic Value of Biomarkers for Heart Disease and Major Adverse Cardiac Events in Patients With Muscular Dystrophy

AIMS

Heart disease is recognized as the leading cause of morbidity and mortality in patients with muscular dystrophy (MD). Our study demonstrates the clinical utility of cardiac biomarkers to improve the diagnosis of cardiomyopathy and prognostication of major adverse cardiac events (MACE) in these vulnerable patients.

METHODS AND RESULTS

We prospectively followed 117 patients (median age, 42 (interquartile range [IQR], 26-50) years; 49 [41.9%] women) at the Neuromuscular Multidisciplinary clinic diagnosed with a dystrophinopathy, limb-girdle MD, type 1 myotonic dystrophy, or facioscapulohumeral MD. We determined that B-type natriuretic peptide (BNP) and high-sensitive troponin I (hsTnI) were effective diagnostic markers of cardiomyopathy (area under the curve [AUC], 0.64; P=0.017; and AUC, 0.69; P=0.001, respectively). Patient risk stratification for MACE was based on cutoff values of BNP and hsTnI defined a priori as 30.5000 pg/mL and 7.6050 ng/L, respectively. Over a median follow-up period of 2.09 (IQR, 1.17-2.81) years there were 36 confirmed MACE. Multivariate regression analyses showed that patients with BNP and hsTnI levels above the respective cutoff values had a 3.70-fold (P=0.001) and 3.24-fold (P=0.002) greater risk of MACE, respectively, compared to patients with biomarker levels below. Furthermore, patients with biomarker levels above both cutoff values had a 4.08-fold (P=0.001) greater risk of MACE. Inflammatory biomarkers did not show clinical utility for heart disease in these patients.

CONCLUSION

Our study demonstrates important diagnostic and prognostic value of BNP and hsTnI as part of a comprehensive cardiac assessment to augment the management and treatment of heart disease in patients with MD.

Evaluation of Molecularly Imprinted Polymers for Point-of-Care Testing for Cardiovascular Disease

Molecular imprinting is a rapidly growing area of interest involving the synthesis of artificial recognition elements that enable the separation of analyte from a sample matrix and its determination. Traditionally, this approach can be successfully applied to small analyte (<1.5 kDa) separation/ extraction, but, more recently it is finding utility in biomimetic sensors. These sensors consist of a recognition element and a transducer similar to their biosensor counterparts, however, the fundamental distinction is that biomimetic sensors employ an artificial recognition element. Molecularly imprinted polymers (MIPs) employed as the recognition elements in biomimetic sensors contain binding sites complementary in shape and functionality to their target analyte. Despite the growing interest in molecularly imprinting techniques, the commercial adoption of this technology is yet to be widely realised for blood sample analysis. This review aims to assess the applicability of this technology for the point-of-care testing (POCT) of cardiovascular disease-related biomarkers. More specifically, molecular imprinting is critically evaluated with respect to the detection of cardiac biomarkers indicative of acute coronary syndrome (ACS), such as the cardiac troponins (cTns). The challenges associated with the synthesis of MIPs for protein detection are outlined, in addition to enhancement techniques that ultimately improve the analytical performance of biomimetic sensors. The mechanism of detection employed to convert the analyte concentration into a measurable signal in biomimetic sensors will be discussed. Furthermore, the analytical performance of these sensors will be compared with biosensors and their potential implementation within clinical settings will be considered. In addition, the most suitable application of these sensors for cardiovascular assessment will be presented.

RAPID-CPU: a prospective study on implementation of the ESC 0/1-hour algorithm and safety of discharge after rule-out of myocardial infarction

Background:

Although the value of fast diagnostic protocols in suspected acute coronary syndrome has been validated, there is insufficient real world evidence including patients with lower pre-test probability, atypical symptoms and confounding comorbidities. The feasibility, efficacy and safety of European Society of Cardiology (ESC) 0/1 and 0/3-hour algorithms using high-sensitivity troponin T were evaluated in a consecutive cohort with suspected acute coronary syndrome.

Methods:

During 12 months, 2525 eligible patients were enrolled. In a pre-implementation period of 6 months, the prevalence of protocols, disposition, lengths of emergency department stay and treatments were registered. Implementation of the 0/1-hour protocol was monitored for another 6 months. Primary endpoints comprised the change of diagnostic protocols and 30-day mortality after direct discharge from the emergency department.

Results:

Use of the ESC 0/1-hour algorithm increased by 270% at the cost of the standard 0/3-hour protocol. After rule-out (1588 patients), 1309 patients (76.1%) were discharged directly from the emergency department, with an all-cause mortality of 0.08% at 30 days (one death due to lung cancer). Median lengths of stay were 2.9 (1.9–3.8) and 3.2 (2.7–4.4) hours using a single high-sensitivity troponin T below the limit of detection (5 ng/L) at presentation and the ESC 0/1-hour algorithm, respectively, as compared to 5.3 (4.7–6.5) hours using the ESC 0/3-hour rule-out protocol (P<0.001). Discharge rates increased from 53.9% to 62.8% (P<0.001), without excessive use of diagnostic resources within 30 days.

Conclusion:

Implementation of the ESC 0/1-hour algorithm is feasible and safe, is associated with shorter emergency department stay than the ESC 0/3-hour protocol, and an increase in discharge rates.

Trial registration:

ClinicalTrials.gov, Unique identifier: NCT03111862.

Susceptibility of Cardiac Troponin Assays to Biotin Interference

OBJECTIVES

To investigate biotin interference on three cardiac troponin (cTn) assays and demonstrate a method to overcome biotin interference.

METHODS

cTn levels were measured in (1) plasma from healthy volunteers on 10-mg daily biotin supplementation mixed with a plasma with known elevated troponin, (2) plasmas with known elevated cTn after mixing in reagent biotin to simulate supplementation, and (3) biotin-spiked plasma specimens pretreated with streptavidin-agarose beads.

RESULTS

Daily biotin ingestion (10 mg) and studies simulating daily biotin use resulted in significant interference in the Gen5 cardiac troponin T (cTnT) assay; the contemporary Gen 4 cTnT and high-sensitivity cardiac troponin I (hs-cTnI) assays were unaffected. The biotin interference threshold was 31, 315, and more than 2,000 ng/mL for Gen5 cTnT, cTnT, and hs-cTnI assays, respectively. Streptavidin pretreatment blocked biotin interference in cTn assays.

CONCLUSIONS

Biotin interference is possible at plasma concentrations achievable by ingestion of over-the-counter supplements that may lead to delayed or missed diagnosis of myocardial injury with the Gen5 cTnT assay.

Cardiac Myosin-Binding Protein C-From Bench to Improved Diagnosis of Acute Myocardial Infarction

Chest pain is responsible for 6-10% of all presentations to acute healthcare providers. Triage is inherently difficult and heavily reliant on the quantification of cardiac Troponin (cTn), as a minority of patients with an ultimate diagnosis of acute myocardial infarction (AMI) present with clear diagnostic features such as ST-elevation on the electrocardiogram. Owing to slow release and disappearance of cTn, many patients require repeat blood testing or present with stable but elevated concentrations of the best available biomarker and are thus caught at the interplay of sensitivity and specificity.We identified cardiac myosin-binding protein C (cMyC) in coronary venous effluent and developed a high-sensitivity assay by producing an array of monoclonal antibodies and choosing an ideal pair based on affinity and epitope maps. Compared to high-sensitivity cardiac Troponin (hs-cTn), we demonstrated that cMyC appears earlier and rises faster following myocardial necrosis. In this review, we discuss discovery and structure of cMyC, as well as the migration from a comparably insensitive to a high-sensitivity assay facilitating first clinical studies. This assay was subsequently used to describe relative abundance of the protein, compare sensitivity to two high-sensitivity cTn assays and test diagnostic performance in over 1900 patients presenting with chest pain and suspected AMI. A standout feature was cMyC's ability to more effectively triage patients. This distinction is likely related to the documented greater abundance and more rapid release profile, which could significantly improve the early triage of patients with suspected AMI.

Inflammatory Biomarkers and Clinical Judgment in the Emergency Diagnosis of Urgent Abdominal Pain

BACKGROUND

The early diagnosis of urgent abdominal pain (UAP) is challenging. Most causes of UAP are associated with extensive inflammation. Therefore, we hypothesized that quantifying inflammation using interleukin-6 and/or procalcitonin would provide incremental value in the emergency diagnosis of UAP.

METHODS

This was an investigator-initiated prospective, multicenter diagnostic study enrolling patients presenting to the emergency department (ED) with acute abdominal pain. Clinical judgment of the treating physician regarding the presence of UAP was quantified using a visual analog scale after initial clinical and physician-directed laboratory assessment, and again after imaging. Two independent specialists adjudicated the final diagnosis and the classification as UAP (life-threatening, needing urgent surgery and/or hospitalization for acute medical reasons) using all information including histology and follow-up. Interleukin-6 and procalcitonin were measured blinded in a central laboratory.

RESULTS

UAP was adjudicated in 376 of 1038 (36%) patients. Diagnostic accuracy for UAP was higher for interleukin-6 [area under the ROC curve (AUC), 0.80; 95% CI, 0.77-0.82] vs procalcitonin (AUC, 0.65; 95% CI, 0.62-0.68) and clinical judgment (AUC, 0.69; 95% CI, 0.65-0.72; both P < 0.001). Combined assessment of interleukin-6 and clinical judgment increased the AUC at presentation to 0.83 (95% CI, 0.80-0.85) and after imaging to 0.87 (95% CI, 0.84-0.89) and improved the correct identification of patients with and without UAP (net improvement in mean predicted probability: presentation, +19%; after imaging, +15%; P < 0.001). Decision curve analysis documented incremental value across the full range of pretest probabilities. A clinical judgment/interleukin-6 algorithm ruled out UAP with a sensitivity of 97% and ruled in UAP with a specificity of 93%.

CONCLUSIONS

Interleukin-6 significantly improves the early diagnosis of UAP in the ED.

Clinical study of serum procalcitonin level in patients with myocardial infarction complicated by pulmonary infection

This study determined the serum procalcitonin (PCT) levels in patients with myocardial infarction complicated by pulmonary infection and explore its clinical significance and diagnostic value. A total of 473 patients who were admitted to the Third Affiliated Hospital of Qiqihar Medical University from January 2016 to June 2017 were enrolled as research subjects. Patients were divided into four groups based on their symptom status in myocardial infarction and pulmonary infection. There were 109 patients in normal control group who did not experience symptoms of either myocardial infarction or pulmonary infection. Blood samples were collected from each patient, and PCT levels were measured. The data were analyzed. The serum PCT levels prior to treatment were compared with each other. The PCT levels in the myocardial infarction and the pulmonary infection group were all higher than that in the normal control group (0.040±0.015) (p<0.05). On the contrary, the serum PCT level in the myocardial infarction complicated by pulmonary infection group was higher than that in the normal control group (p<0.001). The serum PCT level after treatment was compared with that before treatment within the same group. The serum PCT levels in the three disease groups were comparable after treatment. The differences in PCT levels before and after treatment were all statistically significant within all three groups (p<0.05). A patient's serum PCT level was correlated with myocardial infarction complicated by pulmonary infection, which suggested it can be used as an important diagnostic marker for this complication. This finding has important clinical value for predicting and evaluating the complicated condition of myocardial infarction and pulmonary infection by providing a more accurate, sensitive, and specific method for early diagnosis of the disease.

Cardiac Troponin - diagnostic problems and impact on cardiovascular disease

The definition of a high-sensitivity cardiac Troponin (cTn) assay describes the ability to quantify a cardiac biomarker level in at least 50% of healthy individuals. This advance in analytic sensitivity has come with a perceived loss of specificity in the most classic application - chest pain triage and the diagnosis of acute myocardial infarction (AMI). As cardiac Troponin can no longer be used as a dichotomous test, the medical field is increasingly moving towards a more granular interpretation. However, rapid rule-out/rule-in algorithms for AMI still rely on concrete thresholds for efficient triage, irrespective of the patient's comorbidities. Owing to a slightly elevated cTn value, evermore patients appear to fall into an indeterminate risk zone of diagnostic uncertainty. The reasons are manifold, spanning biological variation, analytical issues, increased plasma membrane permeability and the potential cytosolic release of cTn. This review provides a contemporary overview of the literature concerning the use of cardiac Troponin in chronic and acute cardiovascular care. Key messages High-sensitivity cardiac Troponin assays have transformed the assessment of cardiovascular disease. Rapid rule-out algorithms for chest pain triage have become increasingly complicated, but enable safe rule-out. Cardiac Troponin tracks mid- to long-term risk in patients with hyperlipidaemia, heart failure and renal dysfunction.

Combined testing of copeptin and high-sensitivity cardiac troponin T at presentation in comparison to other algorithms for rapid rule-out of acute myocardial infarction

BACKGROUND

We aimed to directly compare the diagnostic and prognostic performance of a dual maker strategy (DMS) with combined testing of copeptin and high-sensitivity (hs) cardiac troponin T (cTnT) at time of presentation with other algorithms for rapid rule-out of acute myocardial infarction (AMI).

METHODS

922 patients presenting to the emergency department with suspected AMI and available baseline copeptin measurements qualified for the present TRAPID-AMI substudy. Diagnostic measures using the DMS (copeptin <10, <14 or < 20 pmol/L and hs-cTnT≤14 ng/L), the 1 h-algorithm (hs-cTnT<12 ng/L and change <3 ng/L at 1 h), as well as the hs-cTnT limit-of-blank (LoB, <3 ng/L) and -detection (LoD, <5 ng/L) were compared. Outcomes were assessed as combined end-points of death and myocardial re-infarction.

RESULTS

True-negative rule-out using the DMS could be achieved in 50.9%-62.3% of all patients compared to 35.0%, 45.3% and 64.5% using LoB, LoD or the 1 h-algorithm, respectively. The DMS showed NPVs of 98.1%-98.3% compared to 99.2% for the 1 h-algorithm, 99.4% for the LoB and 99.3% for the LoD. Sensitivities were 93.5%-94.8%, as well as 96.8%, 98.7% and 98.1%, respectively. Addition of clinical low-risk criteria such as a HEART-score ≤ 3 to the DMS resulted in NPVs and sensitivities of 100% with a true-negative rule-out to 33.8%-41.6%. Rates of the combined end-point of death/MI within 30 days ranged between 0.2% and 0.3% for all fast-rule-out protocols.

CONCLUSION

Depending on the applied copeptin cut-off and addition of clinical low-risk criteria, the DMS might be an alternative to the hs-cTn-only-based algorithms for rapid AMI rule-out with comparable diagnostic measures and outcomes.

"Ultra-sensitive" cardiac troponins: Requirements for effective implementation in clinical practice

The measurement of cardiac troponins, either cardiac troponin I or T, has become the culprit of clinical decision making in patients with suspected acute coronary syndrome (ACS), especially in those with non-ST elevation myocardial infarction (NSTEMI). The leading analytical mainstays of cardiac troponin immunoassays include the limit of blank (LoB), limit of detection (LoD), functional sensitivity, the 99th percentile of a healthy reference population, along with the percentage of "ostensibly healthy" subjects displaying measurable values < 99th percentile. The latest generation of cardiac troponin immunoassays, conventionally defined as "high-sensitive" (HS), is characterized by a LoD over 100-fold lower compared to the first commercialized techniques and a percentage of measurable values consistently > 50% in the general healthy population. The very recent commercialization of methods with further improved analytical sensitivity (i.e., "ultra-sensitive" assays), which allow to measure cardiac troponin values in the vast majority of healthy subjects, is now challenging the diagnostic paradigm based on early rule-out of subjects with cardiac troponin values comprised between the 99th percentile and LoD. New diagnostic strategies, entailing assay-specific cut-offs, must hence be developed and validated in large multicenter studies. The aim of this article is to provide an update on commercially available HS and "ultra"-sensitive techniques for measuring cardiac troponins, along with possible implications of increasingly enhanced analytical sensitivity on diagnostic algorithms for evaluating patients with suspected ACS.

Cost analysis of early discharge using combined copeptin/cardiac troponin testing versus serial cardiac troponin testing in patients with suspected acute coronary syndrome

BACKGROUND

Symptoms indicating acute coronary syndrome are commonly seen in emergency rooms, but only 10% of patients are actually diagnosed with acute myocardial infarction (AMI). The Guidelines for the diagnosis of patients with suspected AMI include either multiple testing of cardiac troponin (cTN) or a single combined test of cTN and copeptin, which facilitates earlier diagnosis or exclusion of AMI. The aim of the present analysis was to investigate the impact of combined copeptin/cTN testing on health care resource consumption and related costs both during and after initial hospital treatment.

METHODS AND RESULTS

The analysis was based on the BIC-8 trial and financial data of participating study sites. A cost analysis was carried out primarily from the hospital perspective and secondarily from the perspective of German statutory health insurers. The underlying assumptions of the investigation were tested for robustness in additional sensitivity analyses. In total, the data of 713 patients (n = 359 combined copeptin/cTN testing, n = 354 serial cTN testing) were evaluated. From a hospital perspective, the combined copeptin/cTN testing showed a reduced number of medical procedures and a lower frequency of inpatient admissions. The average staff time was significantly reduced by a mean of 49 minutes (95% confidence interval (CI) 46 to 53) per patient, accompanied by a significant mean reduction of 131 minutes (95%CI 104 to 158) in the time patients stayed in the emergency room. The initial hospital treatment was less cost-intensive. Over the entire study period, no significant cost differences were observed between the groups for health insurance.

CONCLUSION

The combined copeptin/cTN testing has the potential to save costs and staff time in acute care and for the entire hospital stay. The primary explanations for these findings are early identification and ruling out patients without AMI along with the associated reduced need for acute medical treatment.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01498731.