Direct hospital costs of chest pain patients attending the emergency department: a retrospective study

Early risk assessment in patients with suspected NSTE-ACS; a retrospective cohort study

INTRODUCTION

Chest pain is among the most common reasons for Emergency Department (ED) presentation, while most patients should be considered low risk for Acute Coronary Syndrome (ACS). Management of these patients places a significant burden on our health care system. Various risk scores have been developed to facilitate the triage of patients with chest pain. However, it remains unclear which score performs best in identifying low risk patients, in various settings. The aim of this study was to determine which risk score performs best in ruling out non-ST elevation ACS (NSTE-ACS).

METHODS

Data was collected from all patients >18 years presenting to the ED between 01 and 01-2019 and 01-07-2019, if they were suspected of NSTE-ACS. Primary endpoint was NSTE-ACS during presentation to the ED or hospitalization, according to the 2020 ESC guidelines. In a secondary analysis we determined the number low-risk patients, at set safety levels of 95% and 98%.

RESULTS

A total of 536 patients were included, 192 (35.9%) were admitted to the hospital and NSTE-ACS occurred in 134 of 536 patients (25.0%). When areas under the curve (AUC) were compared, pre-HEART (0.869; CI 0.835-0.903), T-MACS (0.862; CI 0.825-0.898) and HEART (0.850; CI 0.815-0.885) performed best. At a safety level of 98%, the HEART score was the best performing risk score and identified 28.9% of patients as low risk, and missed 0 cases of NSTE-ACS. Followed by the pre-HEART score, which identified 18.3% of all patients as low risk, and missed 0% of NSTE-ACS.

CONCLUSIONS

The newly developed pre-HEART score is both practical and has accurate diagnostic properties, closely followed by the HEART score, and T-MACS. New pre-hospital risk scores are promising and much needed. Future studies should focus on the usage of pre-hospital scores for triage of patients with chest pain, in order to reduce the burden on emergency health care.

Incidence, diagnoses and outcomes of ambulance attendances for chest pain: A population-based cohort study

AIMS

Non-traumatic chest pain is one of the most common reasons for calls for emergency assistance and places a significant burden on health services. This study aimed to determine age- and sex-specific incidences, diagnoses, and outcomes of patients with chest pain attended by paramedics using a large population-based sample.

METHODS

Consecutive emergency medical services (EMS) attendances for non-traumatic chest pain in Victoria, Australia from January 2015 to June 2019 were included. Data were individually linked to emergency, hospital admission and mortality records.

RESULTS

During the study period (representing 22,186,930 person-years), chest pain was the reason for contacting EMS in 257,017 of 2,736,570 attendances (9.4%). Overall incidence of chest pain attendances was 1,158 (per 100,000 person-years) with a higher incidence observed with increasing age, among females, among Aboriginal and Torres Strait Islanders, in regional settings, and in socially disadvantaged areas. The most common diagnoses were non-specific pain (46%; 30-day mortality 0.5%), non-ST elevation myocardial infarction (5.3%; mortality 1.3%), pneumonia (3.8%; mortality 3.9%), stable coronary syndromes (3.5%; mortality 0.8%), unstable angina (3.3%; mortality 1.3%), and ST-elevation myocardial infarction (2.8%; mortality 7.0%), while pulmonary embolism (0.7%; mortality 3.2%) and aortic pathologies (0.2%; mortality 22.2%) were rare.

CONCLUSIONS

Chest pain accounts for one in ten ambulance calls, and underlying causes are diverse, with substantial differences according to age and sex. Almost half of patients are discharged from hospital with a diagnosis of non-specific pain and low rates of mortality.

The Effect of Internet-Delivered Cognitive Behavioral Therapy Versus Psychoeducation Only on Psychological Distress in Patients With Noncardiac Chest Pain: Randomized Controlled Trial

Background

Patients with recurrent episodes of noncardiac chest pain (NCCP) experience cardiac anxiety as they misinterpret the pain to be cardiac related and avoid physical activity that they think could threaten their lives. Psychological interventions, such as internet-delivered cognitive behavioral therapy (iCBT), targeting anxiety can be a feasible solution by supporting patients to learn how to perceive and handle their chest pain.

Objective

This study aims to evaluate the effects of a nurse-led iCBT program on cardiac anxiety and other patient-reported outcomes in patients with NCCP.

Methods

Patients with at least two health care consultations because of NCCP during the past 6 months, and who were experiencing cardiac anxiety (Cardiac Anxiety Questionnaire score ≥24), were randomized into 5 weeks of iCBT (n=54) or psychoeducation (n=55). Patients were aged 54 (SD 17) years versus 57 (SD 16) years and were mainly women (32/54, 59% vs 35/55, 64%). The iCBT program comprised psychoeducation, mindfulness, and exposure to physical activity, with weekly homework assignments. The primary outcome was cardiac anxiety. The secondary outcomes were fear of bodily sensations, depressive symptoms, health-related quality of life, and chest pain frequency. Intention-to-treat analysis was applied, and the patients were followed up for 3 months. Mixed model analysis was used to determine between-group differences in primary and secondary outcomes.

Results

No significant differences were found between the iCBT and psychoeducation groups regarding cardiac anxiety or any of the secondary outcomes in terms of the interaction effect of time and group over the 3-month follow-up. iCBT demonstrated a small effect size on cardiac anxiety (Cohen d=0.31). In the iCBT group, 36% (16/44) of patients reported a positive reliable change score (≥11 points on the Cardiac Anxiety Questionnaire), and thus an improvement in cardiac anxiety, compared with 27% of (13/48) patients in the psychoeducation group. Within-group analysis showed further significant improvement in cardiac anxiety (P=.04) at the 3-month follow-up compared with the 5-week follow-up in the iCBT group but not in the psychoeducation group.

Conclusions

iCBT was not superior to psychoeducation in decreasing cardiac anxiety in patients with NCCP. However, iCBT tends to have better long-term effects on psychological distress, including cardiac anxiety, health-related quality of life, and NCCP frequency than psychoeducation. The effects need to be followed up to draw more reliable conclusions.

Trial Registration

ClinicalTrials.gov NCT03336112; https://www.clinicaltrials.gov/ct2/show/NCT03336112

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.

Single troponin measurement to rule-out acute myocardial infarction in early presenters

BACKGROUND

A single high-sensitive cardiac troponin (hs-cTn) can be used to rule-out acute myocardial infarction (MI) in patients presenting >3 hours (3 h) after chest pain onset to the emergency department. This study aimed to investigate the safety of ruling-out MI in early presenters with chest pain ≤3 h using a single hs-cTnI at admission.

METHODS

We prospectively enrolled patients presenting with chest pain suggestive of MI. Hs-cTnI (Siemens ADVIA Centaur TNIH, Limit of detection: 2.2 ng/L) was measured at admission. Two physicians adjudicated final diagnosis. A diagnostic cut-off value <3 ng/L was used to rule-out MI. Patients were classified as early (chest pain ≤3 h) or late presenters (>3 h).

RESULTS

We included 1370 patients with available admission hs-cTnI results: median (Q1-Q3) age 65 (52-74), female sex: 43%, previous MI: 22%. We confirmed MI in 118 (8.6%) patients. Overall, 470 (34%) patients were classified as early, 770 (56%) as late presenters, and 130 (9%) patients had unknown onset. When applying the diagnostic cut-off value, MI was correctly ruled-out at admission in 370 (27%) patients: 134 (29%) early presenters, 206 (27%) late presenters and 30 (23%) patients with unknown onset. This resulted in an overall negative predictive value of 100% (95% CI: 99.0-100%), with both 100% (97.3-100%) for early and 100% (98.2-100%) for late presenters, respectively. Sensitivity was similarly high in the two groups.

CONCLUSION

MI could be safely ruled-out in all patients presenting with chest pain ≤3 h when using a single hs-cTnI value <3 ng/L as diagnostic cut-off.

TRIAL REGISTRATION NUMBER

NCT03634384.

RACE-IT - Rapid Acute Coronary Syndrome Exclusion using the Beckman Coulter Access high-sensitivity cardiac troponin I: A stepped-wedge cluster randomized trial

BACKGROUND

Protocols utilizing high-sensitivity cardiac troponin (hs-cTn) assays for the evaluation of suspected acute coronary syndrome (ACS) in the emergency department (ED) have been gaining popularity across the US and the world. These protocols more rapidly rule-out ACS and more accurately identify the presence of acute myocardial injury. At this time, few randomized trials have evaluated the safety and operational impact of these assays, resulting in limited evidence to guide the use and implementation of hs-cTn in the ED.

OBJECTIVE

The main study objective is to test the effectiveness of a rapid ACS rule-out pathway using hs-cTnI in safely discharging patients from the ED for whom clinical suspicion for ACS exists.

DESIGN

This prospective, implementation trial (n = 11,070) will utilize a stepped wedge cluster randomized trial design. The design will allow for all participating sites to capture benefit from the implementation of the hs-cTnI pathway while providing data evaluating the effectiveness in providing safe and rapid evaluation of patients with clinical suspicion for ACS.

SUMMARY

Demonstrating that clinical pathways using hs-cTnI can be effectively implemented to rapidly rule-out ACS while conserving costly hospital resources has significant implications for the care of patients with possible acute cardiac conditions in EDs across the US.

CLINICALTRIALSGOV IDENTIFIER

NCT04488913.

Evaluation of the 0 h/1 h high-sensitivity cardiac troponin T algorithm in diagnosis of non-ST-segment elevation myocardial infarction (NSTEMI) in Han population

OBJECTIVES

A rapid 0 h/1 h algorithm using high-sensitivity cardiac troponin T (hs-cTnT) for rule-out and rule-in of non-ST-segment elevation myocardial infarction (NSTEMI) is recommended by the European Society of Cardiology. We aim to prospectively evaluate the diagnostic performance of the algorithm in Chinese Han patients with suspected NSTEMI.

METHODS

In this prospective diagnostic cohort study, 577 patients presenting to the emergency department with suspected NSTEMI and recent (<12 h) onset of symptoms were enrolled. The levels of serum hs-cTnT were measured on admission, 1 h later and 4-14 h later. All patients underwent the initial clinical assessment and were triaged into three groups (rule-out, rule-in and observe) according to the 0 h/1 h algorithm. The major cardiovascular events (MACE) were evaluated at the 7-day and 30-day follow-ups.

RESULTS

Among 577 enrolled patients, NSTEMI was the final diagnosis for 106 (18.4%) patients. Based on the hs-cTnT 0 h/1 h algorithm, 148 patients (25.6%) were classified as rule-out, 278 patients (48.2%) as rule-in and 151 patients (26.2%) were assigned to the observe group. The rule-out approach resulted in a sensitivity of 100% and negative predictive value of 100%. The rule-in approach resulted in a specificity of 62.9% [95% CI (58.5-67.2%)] and positive predictive value of 37.1% [95%CI (31.3-42.8%)]. No MACE was observed in the rule-out group within 30-day follow-up.

CONCLUSIONS

The hs-cTnT 0 h/1 h algorithm is a safe tool for early rule-out of NSTEMI, while probably not an effective strategy for accurate rule-in of NSTEMI in Chinese Han population.

Development of a specific troponin I detection system with enhanced immune sensitivity using a single monoclonal antibody

Using an immunoassay in combination with surface plasmon fluorescence spectroscopy (SPFS), we report the rapid detection of troponin I, a valuable biomarker for diagnosis of myocardial infarction. We discuss the implementation of (i) direct, (ii) sandwich, and (iii) competitive assay formats, based on surface plasmon resonance and SPFS. To elucidate the results, we relate the experiments to orientation-dependent interaction of troponin I epitopes with respective immunoglobulin G antibodies. A limit of detection (LoD) of 19 pM, with 45 min readout time, was achieved using single monoclonal antibody that is specific for one epitope. The borderline between normal people and patients is 20 pM to 83 pM cTnI concentration, and upon the outbreak of acute myocardial infraction it can raise to 2 nM and levels at 20 nM for 6-8 days, therefore the achieved LoD covers most of the clinically relevant range. In addition, this system allows for the detection of troponin I using a single specific monoclonal antibody, which is highly beneficial in case of detection in real samples, where the protein has a complex form leading to hidden epitopes, thus paving the way towards a system that can improve early-stage screening of heart attacks.

A comparative 30-day outcome analysis of inpatient evaluation vs outpatient testing in patients presenting with chest pain in the high-sensitivity troponin era. A propensity score matched case-control retrospective study

Background

The best disposition of chest pain patients who rule out for myocardial infarction (MI) but have non‐low clinical risk scores in the high‐sensitivity troponin era is not well studied.

Hypothesis

In carefully selected patients who rule out for MI, and have a high‐sensitivity troponin T ≤ 50 ng/L with an absolute increase less than 5 ng/L on repeat measurements, early emergency room (ER) discharge might be equivalent to inpatient evaluation in regards to 30‐day incidence of adverse cardiac events (ACEs) regardless of the clinical risk score.

Methods

A total of 12 847 chest pain patients presenting to our health system ERs from January 2017 to September 2019 were retrospectively investigated. A propensity score matching algorithm was used to account for baseline differences between admitted and discharged cohorts. We then estimated and compared the incidence of 30‐day and 1‐year composite ACEs (MI, urgent revascularization, or cardiovascular death) between both groups. A multivariate Cox regression model was used to evaluate the effect of admission on outcomes.

Results

A total of 2060 patients were matched in 1:1 fashion. The primary endpoint of 30‐day composite ACEs occurred in 0.6% and 0.4% of the admission and the discharged cohorts, respectively (P = .76). One‐year composite ACEs was also similar between both groups (4% vs 3.7%, P = .75). In a multivariate Cox regression model, the effect of inpatient evaluation was neutral (hazard ratio 1.1, confidence interval 0.62‐1.9, P = .75).

Conclusions

Inpatient evaluation was not associated with better outcomes in our selected group of patients. Larger‐scale randomized trials are needed to confirm our findings.

High level of circulating microRNA-142 is associated with acute myocardial infarction and reduced survival

BACKGROUND

Recent study reported that microRNA-142 (miR-142) were up-regulated in the atherosclerotic plaques, which may be responsible for pathogenesis of atherosclerosis. However, whether it associates with presence of acute myocardial infarction (AMI), and its prognostic value is still unknown. We, therefore, investigated the association between miR-142 expression and presence of AMI, and its prognostic value in AMI patients.

METHODS

We included 300 AMI patients and 100 subjects as the control group. MiR-142 content was detected by quantitative real-time polymerase chain reaction. MiR-142 level was identified in all subjects. The multivariate logistic regression analysis were performed to evaluate the risk factors of AMI. The Kaplan-Meier analysis was performed to determine the major adverse cardiovascular and cerebrovascular events (MACCE)-free survival.

RESULTS

AMI group had significantly higher miR-142 level in comparison to the controls [4.10 (2.03-7.43) vs. 1.92 (0.91-2.91), p < 0.001], moreover, miR-142 content was significantly associated with cardiac troponin I (cTnI) level (r = 0.707, p < 0.001). The MACCE-free survival was significantly lower over 24-month for patients in miR-142 high expression group (72.4% ± 5.6% vs. 76.4% ± 5.1%) (p = 0.022). After adjusting for the traditional risk factors, the odds ratios of miR-142 was 14.74 (95% CI, 2.15-101.24). The multivariate logistic regression analysis revealed that miR-142 level significantly associated with presence of AMI (p < 0.001).

CONCLUSION

The serum level of miR-142 was increased in AMI patients when compared with health population. Furthermore, use of this marker may allow a certain predictor of the MACCE in AMI patients.

Chest pain in the ambulance; prevalence, causes and outcome - a retrospective cohort study

BACKGROUND

Chest pain is common in acute ambulance transports. This study aims to characterize and compare ambulance-transported chest pain patients to non-chest pain patients and evaluate if patient characteristics and accompanying symptoms accessible at the time of emergency call can predict cause and outcome in chest pain patients.

METHODS

Retrospective, observational population-based study, including acute ambulance transports. Patient characteristics and symptoms are included in a multivariable risk model to identify characteristics, associated with being discharged without an acute cardiac diagnosis and surviving 30 days after chest pain event.

RESULTS

In total, 10,033 of 61,088 (16.4%) acute ambulance transports were due to chest pain. In chest pain patients, 30-day mortality was 2.1% (95%CI 1.8-2.4) compared to 6.0% (95%CI 5.7-6.2) in non-chest pain patients. Of chest pain patients, 1054 (10.5%) were diagnosed with acute myocardial infarction, and 5068 (50.5%) were discharged without any diagnosis of disease. This no-diagnosis group had very low 30-day mortality, 0.4% (95%CI 0.2-0.9). Female gender, younger age, chronic pulmonary disease, absence of accompanying symptoms of dyspnoea, radiation, severe pain for > 5 min, clammy skin, uncomfortable, and nausea were associated with being discharged without an acute cardiac diagnosis and surviving 30 days after a chest pain event.

CONCLUSION

Chest pain is a common reason for ambulance transport, but the majority of patients are discharged without a diagnosis and with a high survival rate. Early risk prediction seems to hold a potential for resource downgrading and thus cost-saving in selected chest pain patients.

Trial design for assessing analytical and clinical performance of high-sensitivity cardiac troponin I assays in the United States: The HIGH-US study

BACKGROUND

High-sensitivity cardiac troponin I (hs-cTnI) assays have been developed that quantify lower cTnI concentrations with better precision versus earlier generation assays. hs-cTnI assays allow improved clinical utility for diagnosis and risk stratification in patients presenting to the emergency department with suspected acute myocardial infarction. We describe the High-Sensitivity Cardiac Troponin I Assays in the United States (HIGH-US) study design used to conduct studies for characterizing the analytical and clinical performance of hs-cTnI assays, as required by the US Food and Drug Administration for a 510(k) clearance application. This study was non-interventional and therefore it was not registered at clinicaltrials.gov.

METHODS

We conducted analytic studies utilizing Clinical and Laboratory Standards Institute guidance that included limit of blank, limit of detection, limit of quantitation, linearity, within-run and between run imprecision and reproducibility as well as potential interferences and high dose hook effect. A sample set collected from healthy females and males was used to determine the overall and sex-specific cTnI 99th percentile upper reference limits (URL). The total coefficient of variation at the female 99th percentile URL and a universally available American Association for Clinical Chemistry sample set (AACC Universal Sample Bank) from healthy females and males was used to examine high-sensitivity (hs) performance of the cTnI assays. Clinical diagnosis of enrolled subjects was adjudicated by expert cardiologists and emergency medicine physicians. Assessment of temporal diagnostic accuracy including sensitivity, specificity, positive predictive value, and negative predictive value were determined at presentation and collection times thereafter. The prognostic performance at one-year after presentation to the emergency department was also performed. This design is appropriate to describe analytical characterization and clinical performance, and allows for acute myocardial infarction diagnosis and risk assessment.

Rapid use of high-sensitive cardiac troponin I for ruling-in and ruling-out of acute myocardial infarction (RACING-MI): study protocol

Introduction

The European Society of Cardiology has suggested an accelerated algorithm for ruling-in and ruling-out myocardial infarction (MI) with high-sensitive cardiac troponin (hs-cTn) measured at admission (0 hour) and after 1 hour (1 hour) as an alternative to standard measurements at 0 hour and 3 hours. However, the 0 hour/1 hour algorithm has only been tested in a limited amount of patient cohorts and not for all hs-cTn assays. Moreover, it is unknown if MI can be ruled-out faster than 1 hour. In this single-centre, clinical trial, we will investigate whether MI safely can be ruled-in or ruled-out after 30 min and 1 hour.

Methods and analysis

Patients with chest pain suggestive of MI admitted to the emergency department will be subjected to hs-cTn measurements at the following time points: 0 hour, 30 min, 1 hour and 3 hours. Chest pain characteristics will be recorded. In total, 1000 patients with all four blood samples will be included. The diagnostic algorithms will be derived based on the first 500 patients and validated in the subsequent 500 patients. The primary endpoint is the negative predictive value of the 0 hour/30 min and the 0 hour/1 hour algorithms. Secondary endpoints include positive predictive value, sensitivity and specificity. Results will be compared with the standard 0 hour/3 hour algorithm.

Ethics and dissemination

Oral and written informed consent will be obtained from all patients. The trial is approved by The Regional Committee on Health Research Ethics and the Danish Data Protection Agency. Data will be disseminated and submitted to peer-reviewed scientific journals and meetings irrespective of study outcome.

Trial registration number

NCT03634384

Immuno-analytical approach and its application for cardiac disease marker detection

Cardiac troponin-I is a promising diagnostic marker for cardiovascular diseases. Troponin-I immunoassays rely on monoclonal antibodies, while polyclonal antibodies, cheaper to manufacture, are uncommonly used. The current study established an immuno-analytical assay using a polyclonal antibody capable of mapping troponin-I antigenic determinant. Proteolytic digestion of troponin-I was performed. Antigenic determinant was assigned by separation of fragments using gel electrophoresis followed by Western blot and high-performance liquid chromatography followed by dot blot. The antigenic determinant region appeared within amino acid sequence 30-90. This robust procedure is suitable for early prognosis of diseases, stratification of patients, and possibly individualized therapy.

A retrospective external validation study of the HEART score among patients presenting to the emergency department with chest pain

Emergency physicians must be able to effectively prognosticate outcomes for patients presenting to the Emergency Department (ED) with chest pain. The HEART score offers a prognostication tool, but external validation studies are limited. We conducted an external retrospective validation study of the HEART score among ED patients presenting to our ED with chest pain from 1 January 2014 to 9 June 2014. We utilized chart review methodology to abstract data from each patient's electronic medical record. We collected data relevant to each of the five elements of the HEART score: history, electrocardiogram (ECG) interpretation, patient age, patient risk factors, and troponin levels. We calculated the diagnostic accuracy of the HEART score (0-10) for predicting the primary outcome of major adverse cardiac events (MACE) over 6 weeks following the ED visit (coronary revascularization, myocardial infarction, or mortality). We randomly selected 10% of patient charts from which a second investigator abstracted all data to assess inter-rater reliability for all study variables. Of 625 charts reviewed, we abstracted data on 417 (66.7%) consecutive patients meeting study inclusion criteria. Thirty-one (7.4%) of these patients experienced 6-week MACE. We observed no instances of MACE within 6 weeks among subjects with a HEART score of 3 or less. The area under the receiver operator curve (AUROC) is 0.885 (95% confidence interval 0.838-0.931). Patients with a HEART score ≤3 are at low risk for 6-week MACE. Hence, these patients may be candidates for outpatient follow-up instead of inpatient admission for cardiac risk stratification.

Impact of the HEART Pathway on Admission Rates for Emergency Department Patients with Chest Pain: An External Clinical Validation Study

BACKGROUND

Chest pain is a common emergency department (ED) chief complaint. Safe discharge mechanisms for low-risk chest pain patients would be useful.

OBJECTIVE

To compare admission rates prior to and after implementation of an accelerated disposition pathway for ED patients with low-risk chest pain based upon the HEART (History, ECG, Age, Risk factors, Troponin) score (HEART pathway).

METHODS

We conducted an impact analysis of the HEART pathway. Patients with a HEART score ≥ 4 underwent hospital admission for cardiac risk stratification and monitoring. Patients with a HEART score ≤ 3 could opt for discharge with 72-h follow-up in lieu of admission. We collected data on cohorts prior to and after implementation of the new disposition pathway. For each cohort, we screened the charts of 625 consecutive chest pain patients. We measured patient demographics, past medical history, vital signs, HEART score, disposition, and 6-week major adverse cardiac events (MACE) using chart review methodology. We compared our primary outcome of hospital admission between the two cohorts.

RESULTS

The admission rate for the preintervention cohort was 63.5% (95% confidence interval [CI] 58.7-68.2%), vs. 48.3% (95% CI 43.7-53.0%) for the postintervention cohort. The absolute difference in admission rates was 15.3% (95% CI 8.7-21.8%). The odds ratio of admission for the postintervention cohort in a logistic regression model controlling for demographics, comorbidities, and vital signs was 0.48 (95% CI 0.33-0.66). One postintervention cohort patient leaving the ED against medical advice (HEART Score 4) experienced 6-week MACE.

CONCLUSIONS

The HEART pathway may provide a safe mechanism to optimize resource allocation for risk-stratifying ED chest pain patients.

Using expert elicitation to estimate the potential impact of improved diagnostic performance of laboratory tests: a case study on rapid discharge of suspected non-ST elevation myocardial infarction patients

Early health technology assessment can provide insight in the potential cost-effectiveness of new tests to guide further development decisions. This can increase their potential benefit but often requires evidence which is lacking in early test development stages. Then, expert elicitation may be used to generate evidence on the impact of tests on patient management. This is illustrated in a case study on a new triple biomarker test (copeptin, heart-type fatty acid binding protein, and high-sensitivity troponin [HsTn]) at hospital admission. The elicited evidence enables estimation of the impact of using the triple biomarker on time to exclusion of non-ST elevation myocardial infarction compared with current serial HsTn measurement (performed 0, 2, and 6 h after admission). Cardiologists were asked to estimate the effect of the triple biomarker on patient's discharge rates and interventions performed, depending on its diagnostic performance. This elicited evidence was combined with Dutch reimbursement data and published evidence into a decision analytic model. Direct hospital costs and patients' discharge rates were assessed for 3 testing strategies including this triple biomarker (ie, only at admission or combined with HsTn measurements after 2 and 6 h). Direct hospital costs of suspected non-ST elevation myocardial infarction patients using serial HsTn measurements are estimated at €1825 per patient. Combining this triple biomarker with HsTn measurements after 2 and 6 hours is expected to be the most cost-effective strategy. Depending on the diagnostic performance of the triple biomarker, this strategy is estimated to reduce costs with €66 to €205 per patient (ie, 3.6%-11.3% reduction). Expert elicitation can be a valuable tool for early health technology assessment to provide an initial estimate of the cost-effectiveness of new tests prior to their implementation in clinical practice. As demonstrated in our case study, improved diagnostic performance of the triple biomarker may have benefits that should be further explored.

Diagnostic accuracy of functional, imaging and biochemical tests for patients presenting with chest pain to the emergency department: A systematic review and meta-analysis

BACKGROUND

Non-invasive ischaemia tests and biomarkers are widely adopted to rule out acute coronary syndrome in the emergency department. Their diagnostic accuracy has yet to be precisely defined.

METHODS

Medline, Cochrane Library CENTRAL, EMBASE and Biomed Central were systematically screened (start date 1 September 2016, end date 1 December 2016). Prospective studies (observational or randomised controlled trial) comparing functional/imaging or biochemical tests for patients presenting with chest pain to the emergency department were included.

RESULTS

Overall, 77 studies were included, for a total of 49,541 patients (mean age 59.9 years). Fast and six-hour highly sensitive troponin T protocols did not show significant differences in their ability to detect acute coronary syndromes, as they reported a sensitivity and specificity of 0.89 (95% confidence interval 0.79-0.94) and 0.84 (0.74-0.9) vs 0.89 (0.78-0.94) and 0.83 (0.70-0.92), respectively. The addition of copeptin to troponin increased sensitivity and reduced specificity, without improving diagnostic accuracy. The diagnostic value of non-invasive tests for patients without troponin increase was tested. Coronary computed tomography showed the highest level of diagnostic accuracy (sensitivity 0.93 (0.81-0.98) and specificity 0.90 (0.93-0.94)), along with myocardial perfusion scintigraphy (sensitivity 0.85 (0.77-0.91) and specificity 0.92 (0.83-0.96)). Stress echography was inferior to coronary computed tomography but non-inferior to myocardial perfusion scintigraphy, while exercise testing showed the lower level of diagnostic accuracy.

CONCLUSIONS

Fast and six-hour highly sensitive troponin T protocols provide an overall similar level of diagnostic accuracy to detect acute coronary syndrome. Among the non-invasive ischaemia tests for patients without troponin increase, coronary computed tomography and myocardial perfusion scintigraphy showed the highest sensitivity and specificity.

Echocardiography in the Evaluation of Chest Pain in the Emergency Department

BACKGROUND

A challenge for clinicians in emergency departments (EDs) is rapid identification of those patients with chest pain who require admission and urgent management and those with low clinical risk who can be discharged safely from the ED. This study was designed with an aim to evaluate the ability of two-dimensional transthoracic echocardiography (2D-TTE) to determine causes of acute chest pain in patients presenting to the ED in order to decide whether hospital admission and further investigations were needed.

MATERIAL/METHODS

A total of 250 consecutive patients admitted with chest pain, were enrolled in this prospective study. Patients were divided into three groups: high risk, moderate risk, and low risk of cardiac events, according to cardiovascular risk factors. 2D-TTE was obtained using the HI vision Avius ultrasound unit (Hitachi). Statistical analysis was performed with the Statistical Package for the Social Sciences (SPSS), version 20.

RESULTS

Ischemic and/or non-ischemic heart diseases (IHD and/or NIHD) were detected in 147 (86.5%), 13 (7.6%), and 10 (5.9%) patients with high, moderate, and low risk, respectively. 2D-TTE was characterized by sensitivity of 85.86%, specificity of 100%, and positive predictive value (PPV) of 100% for detecting causes of chest pain.

CONCLUSIONS

2D-TTE increased specificity and sensitivity of detecting causes of chest pain, when compared to patient history, clinical findings, and electrocardiography (ECG). 2D-TTE can be used to help determine the need for hospital admission, to confirm or exclude diagnosis, and guide urgent therapy.

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

Background

The 1-hour (h) algorithm triages patients presenting with suspected acute myocardial infarction (AMI) to the emergency department (ED) towards “rule-out,” “rule-in,” or “observation,” depending on baseline and 1-h levels of high-sensitivity cardiac troponin (hs-cTn). The economic consequences of applying the accelerated 1-h algorithm are unknown.

Methods and findings

We performed a post-hoc economic analysis in a large, diagnostic, multicenter study of hs-cTnT using central adjudication of the final diagnosis by two independent cardiologists. Length of stay (LoS), resource utilization (RU), and predicted diagnostic accuracy of the 1-h algorithm compared to standard of care (SoC) in the ED were estimated. The ED LoS, RU, and accuracy of the 1-h algorithm was compared to that achieved by the SoC at ED discharge. Expert opinion was sought to characterize clinical implementation of the 1-h algorithm, which required blood draws at ED presentation and 1h, after which “rule-in” patients were transferred for coronary angiography, “rule-out” patients underwent outpatient stress testing, and “observation” patients received SoC. Unit costs were for the United Kingdom, Switzerland, and Germany. The sensitivity and specificity for the 1-h algorithm were 87% and 96%, respectively, compared to 69% and 98% for SoC. The mean ED LoS for the 1-h algorithm was 4.3h—it was 6.5h for SoC, which is a reduction of 33%. The 1-h algorithm was associated with reductions in RU, driven largely by the shorter LoS in the ED for patients with a diagnosis other than AMI. The estimated total costs per patient were £2,480 for the 1-h algorithm compared to £4,561 for SoC, a reduction of up to 46%.

Conclusions

The analysis shows that the use of 1-h algorithm is associated with reduction in overall AMI diagnostic costs, provided it is carefully implemented in clinical practice. These results need to be prospectively validated in the future.

Early Diagnostic Performance of Heart-Type Fatty Acid Binding Protein in Suspected Acute Myocardial Infarction: Evidence From a Meta-Analysis of Contemporary Studies

BACKGROUND

Although cardiac troponin is the cornerstone in diagnosis of acute myocardial infarction (AMI), the accuracy is still suboptimal in the early hours after chest pain onset. Due to its small size, heart-type fatty acid-binding protein (H-FABP) has been reported accurate in diagnosis of AMI, however, this remains undetermined. The aim is to investigate the diagnostic performance of H-FABP alone and in conjunction with high-sensitivity troponin (hs-Tn) within 6 hours of symptom onset. Furthermore, accuracy in 0h/3h algorithm was also assessed.

METHODS

Medline and EMBASE databases were searched; sensitivity, specificity and area under ROC curve (AUC) were used as measures of the diagnostic accuracy. We pooled data on bivariate modelling, threshold effect and publication bias was applied for heterogeneity analysis.

RESULTS

Twenty-two studies with 6602 populations were included, pooled sensitivity, specificity and AUC of H-FABP were 0.75 (0.68-0.81), 0.81 (0.75-0.86) and 0.85 (0.82-0.88) within 6 hours. Similar sensitivity (0.76, 0.69-0.82), specificity (0.80, 0.71-0.87) and AUC (0.85, 0.82-0.88) of H-FABP were observed in 4185 (63%) patients in 0h/3h algorithm. The additional use of H-FABP improved the sensitivity of hs-Tn alone but worsened its specificity (all p<0.001), and resulted in no improvement of AUC (p>0.99). There was no threshold effect (p=0.18) and publication bias (p=0.31) in this study.

CONCLUSIONS

H-FABP has modest accuracy for early diagnosis of AMI within 3 and 6 hours of symptom onset. The incremental value of H-FABP seemed much smaller and was of uncertain clinical significance in addition to hs-Tn in patients with suspected AMI. Routine use of H-FABP in early presentation does not seem warranted.

Prehospital diagnosis of patients with acute myocardial infarction

Primary percutaneous intervention (PPCI) is the preferred treatment in patients with ST elevation myocardial infarction (STEMI) if this can be performed in a timely manner. The

Safety and efficacy of the 0 h/3 h protocol for rapid rule out of myocardial infarction

BACKGROUND

The early and accurate diagnosis of acute myocardial infarction (AMI) is an important medical and economic challenge. We aimed to prospectively evaluate the performance of the new European Society of Cardiology rapid 0-hour/3-hour (0 h/3 h) rule out protocol for AMI.

METHODS

We enrolled 2,727 consecutive patients presenting with suspected AMI without persistent ST-segment elevation to the emergency department in a prospective international multicenter study. The final diagnosis was adjudicated by 2 independent cardiologists. The performance of the 0 h/3 h rule out protocol was evaluated using 4 high-sensitivity (primary analysis) and 3 sensitive cardiac troponin (cTn) assays.

RESULTS

Acute myocardial infarction was the final diagnosis in 473 patients (17.3%). Using the 4 high-sensitivity cTn assays, the 0-hour rule out protocol correctly ruled out 99.8% (95% [confidence interval] CI, 98.7%-100%), 99.6% (95% CI, 98.5%-99.9%), 100% (95% CI, 97.9%-100%), and 100% (95% CI, 98.0%-100%) of late presenters (>6 h from chest pain onset). The 3-hour rule out protocol correctly ruled out 99.9% (95% CI, 99.1%-100%), 99.5% (95% CI, 98.3%-99.9%), 100% (95% CI, 98.1%-100%), and 100% (95% CI, 98.2%-100%) of early presenters (<6 h from chest pain onset). Using the 3 sensitive cTn assays, the 0-hour rule out protocol correctly ruled out 99.6% (95% CI, 98.6%-99.9%), 99.0% (95% CI, 96.9%-99.7%), and 99.1% (95% CI, 97.2%-99.8%) of late presenters; and the 3-hour rule out protocol correctly ruled out 99.4% (95% CI, 98.3%-99.8%), 99.2% (95% CI, 97.3%-99.8%), and 99.0% (95% CI, 97.2%-99.7%) of early presenters. Overall, the 0 h/3 h rule out protocol assigned 40% to 60% of patients to rule out. None of the patients assigned rule out died during 3-months follow-up.

CONCLUSIONS

The 0 h/3 h rule out protocol seems to allow the accurate rule out of AMI using both high-sensitivity and sensitive cTn measurements in conjunction with clinical assessment. Additional studies are warranted for external validation.

Guided Internet-delivered cognitive behavioural therapy in patients with non-cardiac chest pain - a pilot randomized controlled study

BACKGROUND

Patients with recurrent episodes of non-cardiac chest pain may experience cardiac anxiety and avoidance behavior, leading to increased healthcare utilization. These patients might benefit from help and support to evaluate the perception and management of their chest pain. The purpose of this study was to test the feasibility of a short guided Internet-delivered cognitive behavioural therapy (CBT) program and explore the effects on cardiac anxiety, fear of body sensations, depressive symptoms, and chest pain in patients with non-cardiac chest pain, compared with usual care.

METHODS

A pilot randomized controlled study was conducted. Fifteen patients with non-cardiac chest pain with cardiac anxiety or fear of body sensations, aged 22-76 years, were randomized to intervention (n = 7) or control (n = 8) groups. The four-session CBT program contained psychoeducation, physical activity, and relaxation. The control group received usual care. Data were collected before and after intervention.

RESULTS

Five of seven patients in the intervention group completed the program, which was perceived as user-friendly with comprehensible language, adequate and varied content, and manageable homework assignments. Being guided and supported, patients were empowered and motivated to be active and complete the program. Patients in both intervention and control groups improved with regard to cardiac anxiety, fear of body sensations, and depressive symptoms, but no significant differences were found between the groups.

CONCLUSIONS

The Internet-delivered CBT program seems feasible for patients with non-cardiac chest pain, but needs to be evaluated in larger groups and with a longer follow-up period.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02336880 . Registered on 8 January 2015.

Cost-effectiveness of chiropractic care versus self-management in patients with musculoskeletal chest pain

Aims

To assess whether primary sector healthcare in the form of chiropractic care is cost-effective compared with self-management in patients with musculoskeletal chest pain, that is, a subgroup of patients with non-specific chest pain.

Methods and results

115 adults aged 18–75 years with acute, non-specific chest pain of musculoskeletal origin were recruited from a cardiology department in Denmark. After ruling out acute coronary syndrome and receiving usual care, patients with musculoskeletal chest pain were randomised to 4 weeks of community-based chiropractic care (n=59) or to a single information session aimed at encouraging self-management as complementary to usual care (n=56). Data on resource use were obtained from Danish national registries and valued from a societal perspective. Patient cost and health-related quality-adjusted life years (QALYs; based on EuroQol five-dimension questionnaire (EQ-5D) and Short Form 36-item Health Survey (SF-36)) were compared in cost-effectiveness analyses over 12 months from baseline. Mean costs were €2183 lower for the group with chiropractic care, but not statistically significant (95% CI −4410.5 to 43.0). The incremental cost-effectiveness ratio suggested that chiropractic care was cost-effective with a probability of 97%, given a threshold value of €30 000 per QALY gained. In both groups, there was an increase in the health-related quality of life, and the mean increases were similar over the 12-month evaluation period. The mean differences in QALYs between the groups were negligible.

Conclusions

Chiropractic care was more cost-effective than self-management. Therefore, chiropractic care can be seen as a good example of a targeted primary care approach for a subgroup of patients with non-specific chest pain.

Trial registration number

NCT00462241.

Incremental value of copeptin in suspected acute myocardial infarction very early after symptom onset

BACKGROUND

Patients presenting very early after chest pain onset may provide a diagnostic challenge even when using a high-sensitivity cardiac troponin (hs-cTnT). We hypothesized that in these patients the incremental value of copeptin in the early diagnosis of acute myocardial infarction (AMI) may be substantial.

METHODS

We aimed to investigate the incremental value of copeptin in a pre-specified subgroup analysis of patients presenting with suspected AMI to the emergency department within 2 hours of symptom onset in a multicenter study. Copeptin was measured in a blinded fashion. Two independent cardiologists adjudicated the final diagnosis using all available clinical informations, including high-sensitivity cardiac troponin T (hs-cTnT).

RESULTS

Overall, 2000 patients were enrolled, of whom 519 (26%) arrived within 2 hours of symptom onset. Of these, 102 patients (20%) had an AMI. The additional use of copeptin did not increase diagnostic accuracy as quantified by the area under the receiver-operating characteristic curve (AUC) of hs-cTnT (0.87 (95% confidence interval (CI): 0.83-0.90) for hs-cTnT alone to 0.86 (95% CI: 0.82-0.90) for the combination; p = NS). Copeptin (using 9 pmol/L as a cut-off) increased the negative predictive value (NPV) of hs-cTnT (using 14 ng/L as a cut-off) alone from 93% (95% CI: 90-95%) to 96% (95% CI: 93-98%). The NPV for the combination of hs-cTnT and copeptin was lower in patients arriving in the first 2 hours than in those arriving after 2 hours: 96% (95% CI: 93-98%) versus 99% (95% CI: 99-100%), respectively.

CONCLUSIONS

The additional use of copeptin on top of hs-cTnT seems to lead to a small increase in NPV, but no increase in AUC. Routine use of copeptin in early presenters does not seem warranted.

COMPUTER AIDED DIAGNOSIS FOR CARDIOVASCULAR DISEASES BASED ON ECG SIGNALS: A SURVEY

The interpretation of Electroencephalography (ECG) signals is difficult, because even subtle changes in the waveform can indicate a serious heart disease. Furthermore, these waveform changes might not be present all the time. As a consequence, it takes years of training for a medical practitioner to become an expert in ECG-based cardiovascular disease diagnosis. That training is a major investment in a specific skill. Even with expert ability, the signal interpretation takes time. In addition, human interpretation of ECG signals causes interoperator and intraoperator variability. ECG-based Computer-Aided Diagnosis (CAD) holds the promise of improving the diagnosis accuracy and reducing the cost. The same ECG signal will result in the same diagnosis support regardless of time and place. This paper introduces both the techniques used to realize the CAD functionality and the methods used to assess the established functionality. This survey aims to instill trust in CAD of cardiovascular diseases using ECG signals by introducing both a conceptional overview of the system and the necessary assessment methods.

Diagnosis of Acute Myocardial Infarction in Hemodialysis Patients With High-Sensitivity Cardiac Troponin T Assay

Context

Cardiac troponins have become the gold standard for diagnosing acute myocardial infarction (AMI) in the general population; however, their diagnostic accuracy for hemodialysis (HD) patients presenting with chest pain or dyspnea is uncertain.

Objective

To examine the diagnostic accuracy of high-sensitivity cardiac troponin T (hs-cTnT) assay for AMI in HD patients.

Design

In this prospective study, we enrolled 670 consecutive stable HD patients presenting with chest pain or dyspnea on routine predialysis therapy in the nephrology department. Receiver operating characteristic (ROC) curves were used to examine the diagnostic accuracy of hs-cTnT levels at enrollment in HD patients presenting with chest pain or dyspnea, and the dynamic change in these levels after 3 hours.

Results

Acute myocardial infarction was the adjudicated final diagnosis in 12% of HD patients. Among patients with a final diagnosis other than AMI, 97% had a plasma hs-cTnT concentration above the 99th percentile. At the time of enrollment, the area under the ROC curve of hs-cTnT levels for diagnosis of AMI was 0.68 (95% confidence interval [CI], 0.62–0.74; P &lt; .001) with a cutoff value of 107.7 ng/L; the relative change after 3 hours was 0.90 (95% CI, 0.82–0.96, P &lt; .001) with a cutoff value of 24%, and the absolute change was 0.88 (95% CI, 0.82–0.94, P &lt; .001) with a cutoff value of 32.6 ng/L. The prognostic value for 40-day mortality varied with the magnitude of elevation in hs-cTnT levels.

Conclusions

Tracking the dynamic change in hs-cTnT levels during the short term significantly increased this measure's diagnostic accuracy for AMI in HD patients.

One-hour rule-in and rule-out of acute myocardial infarction using high-sensitivity cardiac troponin I

We aimed to prospectively derive and validate a novel 0-/1-hour algorithm using high-sensitivity cardiac troponin I (hs-cTnI) for the early "rule-out" and "rule-in" of acute myocardial infarction (AMI).

METHODS

In a prospective multicenter diagnostic study, we enrolled 1,500 patients presenting with suspected AMI to the emergency department. The final diagnosis was centrally adjudicated by 2 independent cardiologists blinded to hs-cTnI concentrations. The hs-cTnI (Siemens Vista) 0-/1-hour algorithm incorporated measurements performed at baseline and absolute changes within 1 hour, was derived in the first 750 patients (derivation cohort), and then validated in the second 750 (validation cohort).

RESULTS

Overall, AMI was the final diagnosis in 16% of patients. Applying the hs-cTnI 0-/1-hour algorithm developed in the derivation cohort to the validation cohort, 57% of patients could be classified as "rule-out"; 10%, as "rule-in"; and 33%, as "observe." In the validation cohort, the sensitivity and the negative predictive value for AMI in the "rule-out" zone were 100% (95% CI 96%-100%) and 100% (95% CI 99%-100%), respectively. The specificity and the positive predictive value (PPV) for AMI in the "rule-in" zone were 96% (95% CI 94%-97%) and 70% (95% CI 60%-79%), respectively. Negative predictive value and positive predictive value of the 0-/1-hour algorithm were higher compared to the standard of care combining hs-cTnI with the electrocardiogram (both P < .001).

CONCLUSION

The hs-cTnI 0-/1-hour algorithm performs very well for early rule-out as well as rule-in of AMI. The clinical implications are that used in conjunction with all other clinical information, the 0-/1-hour algorithm will be a safe and effective approach to substantially reduce time to diagnosis.

Optimizing Early Rule-Out Strategies for Acute Myocardial Infarction: Utility of 1-Hour Copeptin

BACKGROUND

Combined testing of high-sensitivity cardiac troponin T (hs-cTnT) and copeptin at presentation provides a very high—although still imperfect—negative predictive value (NPV) for the early rule-out of acute myocardial infarction (AMI). We hypothesized that a second copeptin measurement at 1 h might further increase the NPV.

METHODS

In a prospective diagnostic multicenter study, we measured hs-cTnT and copeptin concentrations at presentation and at 1 h in 1439 unselected patients presenting to the emergency department with suspected AMI. The final diagnosis was adjudicated by 2 independent cardiologists blinded to copeptin concentrations. We investigated the incremental value of 1-h copeptin in the rule-out setting (0-h hs-cTnT negative and 0-h copeptin negative) and the intermediate-risk setting (0-h hs-cTnT negative and 0-h copeptin positive).

RESULTS

The adjudicated diagnosis was AMI in 267 patients (18.6%). For measurements obtained at presentation, the NPV in the rule-out setting was 98.6% (95% CI, 97.4%–99.3%). Whereas 1-h copeptin did not increase the NPV significantly, 1-h hs-cTnT did, to 99.6% (95% CI, 98.7%–99.9%, P = 0.008). Similarly, in the intermediate-risk setting (NPV 92.8%, 95% CI, 88.7%–95.8%), 1-h copeptin did not significantly increase the NPV (P = 0.751), but 1-h hs-cTnT did, to 98.6 (95% CI, 96%–99.7%, P &lt; 0.001).

CONCLUSIONS

One-hour copeptin increased neither the safety of the rule-out process nor the NPV in the intermediate-risk setting. In contrast, the incremental value of 1-h hs-cTnT was substantial in both settings. ClinicalTrials.gov/NCT00470587

One-hour rule-in and rule-out of acute myocardial infarction using high-sensitivity cardiac troponin I

OBJECTIVE

We aimed to prospectively derive and validate a novel 1h-algorithm using high-sensitivity cardiac troponin I (hs-cTnI) for early rule-out and rule-in of acute myocardial infarction.

METHODS

We performed a prospective multicenter diagnostic study enrolling 1811 patients with suspected acute myocardial infarction. The final diagnosis was centrally adjudicated by 2 independent cardiologists using all available information, including coronary angiography, echocardiography, follow-up data, and serial measurements of hs-cTnT (but not hs-cTnI). The hs-cTnI 1h-algorithm, incorporating measurements performed at baseline and absolute changes within 1 hour, was derived in a randomly selected sample of 906 patients (derivation cohort), and then validated in the remaining 905 patients (validation cohort).

RESULTS

Acute myocardial infarction was the final diagnosis in 18% of patients. After applying the hs-cTnI 1h-algorithm developed in the derivation cohort to the validation cohort, 50.5% of patients could be classified as "rule-out," 19% as "rule-in," 30.5% as "observe." In the validation cohort, the negative predictive value for acute myocardial infarction in the "rule-out" zone was 99.6% (95% confidence interval, 98.4%-100%), and the positive predictive value for acute myocardial infarction in the "rule-in" zone was 73.9% (95% confidence interval, 66.7%-80.2%). Negative predictive value of the 1h-algorithm was higher compared with the classical dichotomous interpretation of hs-cTnI and to the standard of care combining hs-cTnI with the electrocardiogram (both P < .001). Positive predictive value also was higher compared with the standard of care (P < .001).

CONCLUSION

Using a simple algorithm incorporating baseline hs-cTnI values and the absolute change within the first hour allows safe rule-out as well as accurate rule-in of acute myocardial infarction in 70% of patients presenting with suspected acute myocardial infarction.

Early rule-out and rule-in of myocardial infarction using sensitive cardiac Troponin I

BACKGROUND

It is currently unknown, whether and to what extent sensitive cardiac troponin (s-cTn) allows shortening of the time required for safe rule-out and rule-in of acute myocardial infarction (AMI).

METHODS

We aimed to develop and validate early rule-out and rule-in algorithms for AMI using a thoroughly-examined and commonly used s-cTnI assay in a prospective multicenter study including 2173 patients presenting to the emergency department with suspected AMI. S-cTnI was measured in a blinded fashion at 0 h, 1 h, and 2 h. The final diagnosis was centrally adjudicated by two independent cardiologists. In the derivation cohort (n = 1496), we developed 1h- and 2h-algorithms assigning patients to "rule-out", "rule-in", or "observe". The algorithms were then prospectively validated in the validation cohort (n = 677).

RESULTS

AMI was the adjudicated diagnosis in 17% of patients. After applying the s-cTnI 1h-algorithm developed in the derivation cohort to the validation cohort, 65% of patients were classified as "rule-out", 12% as "rule-in", and 23% to "observe". The negative predictive value for AMI in the "rule-out" group was 98.6% (95% CI, 96.9-99.5), the positive predictive value for AMI in the "rule-in" group 76.3% (95% CI, 65.4-85.1). Overall, 30-day mortality was 0.2% in the "rule-out" group, 1.0% in the "observe" group, and 3.0% in the "rule-in" group. Similar results were obtained for the 2h-algorithm.

CONCLUSION

When used in conjunction with other clinical information including the ECG, a simple algorithm incorporating s-cTnI values at presentation and after 1h (or 2h) will allow safe rule-out and accurate rule-in of AMI in the majority of patients.

Optimal Cutoff Levels of More Sensitive Cardiac Troponin Assays for the Early Diagnosis of Myocardial Infarction in Patients With Renal Dysfunction

Supplemental Digital Content is available in the text.

Background—

It is unknown whether more sensitive cardiac troponin (cTn) assays maintain their clinical utility in patients with renal dysfunction. Moreover, their optimal cutoff levels in this vulnerable patient population have not previously been defined.

Methods and Results—

In this multicenter study, we examined the clinical utility of 7 more sensitive cTn assays (3 sensitive and 4 high-sensitivity cTn assays) in patients presenting with symptoms suggestive of acute myocardial infarction. Among 2813 unselected patients, 447 (16%) had renal dysfunction (defined as Modification of Diet in Renal Disease–estimated glomerular filtration rate <60 mL·min⁻¹·1.73 m⁻²). The final diagnosis was centrally adjudicated by 2 independent cardiologists using all available information, including coronary angiography and serial levels of high-sensitivity cTnT. Acute myocardial infarction was the final diagnosis in 36% of all patients with renal dysfunction. Among patients with renal dysfunction and elevated baseline cTn levels (≥99th percentile), acute myocardial infarction was the most common diagnosis for all assays (range, 45%–80%). In patients with renal dysfunction, diagnostic accuracy at presentation, quantified by the area under the receiver-operator characteristic curve, was 0.87 to 0.89 with no significant differences between the 7 more sensitive cTn assays and further increased to 0.91 to 0.95 at 3 hours. Overall, the area under the receiver-operator characteristic curve in patients with renal dysfunction was only slightly lower than in patients with normal renal function. The optimal receiver-operator characteristic curve–derived cTn cutoff levels in patients with renal dysfunction were significantly higher compared with those in patients with normal renal function (factor, 1.9–3.4).

Conclusions—

More sensitive cTn assays maintain high diagnostic accuracy in patients with renal dysfunction. To ensure the best possible clinical use, assay-specific optimal cutoff levels, which are higher in patients with renal dysfunction, should be considered.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00470587.

Suspected acute coronary syndrome in the emergency room: Limited added value of heart type fatty acid binding protein point of care or ELISA tests: The FAME-ER (Fatty Acid binding protein in Myocardial infarction Evaluation in the Emergency Room) study

BACKGROUND

Timely recognition of acute coronary syndrome remains a challenge as many biomarkers, including troponin, remain negative in the first hours following the onset of chest pain. We assessed the diagnostic accuracy of heart-type fatty acid binding protein (H-FABP), a cardiac biomarker with potential value immediately post symptom onset.

METHODS AND RESULTS

Prospective monocentre diagnostic accuracy study of H-FABP bedside point of care (CardioDetect®) and ELISA tests in acute coronary syndrome suspected patients presenting within 24 hours of symptom onset to the emergency department, in addition to clinical findings, electrocardiography and the currently recommended biomarker high sensitivity troponin-T (hs-cTnT). The final diagnosis of acute coronary syndrome was adjudicated by two independent cardiologists, blinded to H-FABP results. Acute coronary syndrome was diagnosed in 149 (32.9%) of 453 unselected patients with suspected acute coronary syndrome (56% men, mean age 62.6 years). Negative predictive values were similar for H-FABP point of care and ELISA tests (79% vs. 78% respectively), but inferior to initial hs-cTnT (negative predictive value 86%). The addition of H-FABP point of care results to hs-cTnT increased the negative predictive value to 89%. In a multivariable logistic regression model, H-FABP point of care and ELISA tests yielded relevant diagnostic information in addition to clinical findings and ECG (likelihood ratio test p<0.001) and increased area under the receiver operating characteristics curve (AUC; 0.82 vs. 0.84 and 0.84). This added value attenuated, however, after inclusion of hs-cTnT in the diagnostic model (AUC 0.88).

CONCLUSIONS

In patients suspected of acute coronary syndrome presenting to the emergency department, H-FABP testing improves diagnostic accuracy in addition to clinical findings and electrocardiography. H-FABP, however, has no additional diagnostic value when hs-cTnT measurements are also available.

Prospective validation of a 1-hour algorithm to rule-out and rule-in acute myocardial infarction using a high-sensitivity cardiac troponin T assay

BACKGROUND

We aimed to prospectively validate a novel 1-hour algorithm using high-sensitivity cardiac troponin T measurement for early rule-out and rule-in of acute myocardial infarction (MI).

METHODS

In a multicentre study, we enrolled 1320 patients presenting to the emergency department with suspected acute MI. The high-sensitivity cardiac troponin T 1-hour algorithm, incorporating baseline values as well as absolute changes within the first hour, was validated against the final diagnosis. The final diagnosis was then adjudicated by 2 independent cardiologists using all available information, including coronary angiography, echocardiography, follow-up data and serial measurements of high-sensitivity cardiac troponin T levels.

RESULTS

Acute MI was the final diagnosis in 17.3% of patients. With application of the high-sensitivity cardiac troponin T 1-hour algorithm, 786 (59.5%) patients were classified as "rule-out," 216 (16.4%) were classified as "rule-in" and 318 (24.1%) were classified to the "observational zone." The sensitivity and the negative predictive value for acute MI in the rule-out zone were 99.6% (95% confidence interval [CI] 97.6%-99.9%) and 99.9% (95% CI 99.3%-100%), respectively. The specificity and the positive predictive value for acute MI in the rule-in zone were 95.7% (95% CI 94.3%-96.8%) and 78.2% (95% CI 72.1%-83.6%), respectively. The 1-hour algorithm provided higher negative and positive predictive values than the standard interpretation of highsensitivity cardiac troponin T using a single cut-off level (both p < 0.05). Cumulative 30-day mortality was 0.0%, 1.6% and 1.9% in patients classified in the rule-out, observational and rule-in groups, respectively (p = 0.001).

INTERPRETATION

This rapid strategy incorporating high-sensitivity cardiac troponin T baseline values and absolute changes within the first hour substantially accelerated the management of suspected acute MI by allowing safe rule-out as well as accurate rule-in of acute MI in 3 out of 4 patients.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00470587.

Two-hour algorithm for triage toward rule-out and rule-in of acute myocardial infarction using high-sensitivity cardiac troponin T

BACKGROUND

High-sensitivity cardiac troponin (hs-cTn) may allow an earlier diagnosis of acute myocardial infarction (AMI).

METHODS

We prospectively enrolled 1148 (derivation cohort) and 517 (external validation cohort) unselected patients presenting with suspected AMI to the emergency department. Final diagnosis was adjudicated by 2 independent cardiologists. Hs-cTnT was measured at presentation and after 2 hours. A diagnostic algorithm incorporating hs-cTnT values at presentation and absolute changes within the first 2 hours was derived.

RESULTS

AMI was the final diagnosis in 16% of patients in the derivation and 9.1% in the validation cohort. The 2-hour algorithm developed in the derivation cohort classified 60% of patients as "rule-out," 16% as "rule-in," and 24% in the "observational-zone." Resulting sensitivity and negative predictive value (NPV) were 99.5% and 99.9%, respectively, for rule-out, and specificity and positive predictive value (PPV) were 96% and 78%, respectively, for rule-in. Applying the 2-hour triage algorithm in the external validation cohort, 78% of patients could be classified as "rule-out," 8% as "rule-in," and 14% in the "observational-zone." Resulting sensitivity and NPV were 96% and 99.5%, respectively, for rule-out, and specificity and PPV were 99% and 85%, respectively, for rule-in. Cumulative 30-day survival rates were 100%, 98.9%, and 95.2% (P < .001), and 100%, 100%, and 95% (P < .001) in patients classified as "rule-out," "observational-zone," and "rule-in" in the 2 cohorts, respectively.

CONCLUSIONS

A simple algorithm incorporating hs-cTnT baseline values and absolute changes over 2 hours allowed a triage toward safe rule-out, or accurate rule-in, of AMI in the vast majority of patients, with only 20% requiring more prolonged monitoring and serial blood sampling.

Rapidly rule out acute myocardial infarction by combining copeptin and heart-type fatty acid-binding protein with cardiac troponin

Background

The rapid exclusion of acute myocardial infarction in patients with chest pain can reduce the length of hospital admission, prevent unnecessary diagnostic work-up and reduce the burden on our health-care systems. The combined use of biomarkers that are associated with different pathophysiological aspects of acute myocardial infarction could improve the early diagnostic assessment of patients presenting with chest pain.

Methods

We measured cardiac troponin I, copeptin and heart-type fatty acid-binding protein concentrations in 584 patients who presented to the emergency department with acute chest pain. The diagnostic performances for the diagnosis of acute myocardial infarction and NSTEMI were calculated for the individual markers and their combinations. Separate calculations were made for patients presenting to the emergency department <3 h, 3–6 h and 6–12 h after chest pain onset.

Results

For ruling out acute myocardial infarction, the net predictive values (95% CI) of cardiac troponin I, copeptin and heart-type fatty acid-binding protein were 90.4% (87.3–92.9), 84% (79.8–87.6) and 87% (83.5–90), respectively. Combining the three biomarkers resulted in a net predictive value of 95.8% (92.8–97.8). The improvement was most pronounced in the early presenters (<3 h) where the combined net predictive value was 92.9% (87.3–96.5) compared to 84.6% (79.4–88.9) for cardiac troponin I alone. The area under the receiver operating characteristic for the triple biomarker combination increased significantly ( P < 0.05) compared to that of cardiac troponin I alone (0.880 [0.833–0.928] vs. 0.840 [0.781–0.898], respectively).

Conclusions

Combining copeptin, heart-type fatty acid-binding protein and cardiac troponin I measurements improves the diagnostic performance in patients presenting with chest pain. Importantly, in patients who present early (<3 h) after chest pain onset, the combination improves the diagnostic performance compared to the standard cardiac troponin I measurement alone.

Characteristics and outcome among patients who dial for the EMS due to chest pain

OBJECTIVES

This study aims to describe patients who called for the emergency medical service (EMS) due to chest discomfort, in relation to gender and age.

METHODS

All patients who called the emergency dispatch centre of western Sweden due to chest discomfort, between May 2009 and February 2010, were included. Initial evaluation, aetiology and outcome are described as recorded in the databases at the dispatch centre, the EMS systems and hospitals. Patients were divided into the following age groups: ≤50, 51-64 and ≥65 years.

RESULTS

In all, 14,454 cases were enrolled. Equal proportions of men (64%) and women (63%) were given dispatch priority 1. The EMS clinicians gave priority 1 more frequently to men (16% versus 12%) and older individuals (10%, 15% and 14%, respective of age group). Men had a significantly higher frequency of central chest pain (83% versus 81%); circulatory compromise (34% versus 31%); ECG signs of ischaemia (17% versus 11%); a preliminary diagnosis of acute coronary syndrome (40% versus 34%); a final diagnosis of acute myocardial infarction (14% versus 9%) and any potentially life-threatening condition (18% versus 12%). Individuals aged ≥65 years were given a lower priority than individuals aged 51-64 years, despite poorer characteristics and outcome. In all, 78% of cases with a potentially life-threatening condition and 67% of cases that died within 30 days of enrolment received dispatch priority 1. Mortality at one year was 1%, 4% and 18% in each individual age group.

CONCLUSION

Men and the elderly were given a disproportionately low priority by the EMS.

Out-of-hours exercise treadmill testing reduces length of hospital stay for chest pain admissions

AIMS

The objective was to examine the impact of out-of-hours exercise treadmill tests (ETTs) on length of hospital stay (LOS) for patients admitted to a chest pain assessment unit with symptoms suggestive of acute coronary syndrome.

METHODS

Prospective observational study with 30-day follow-up of low-to-intermediate-risk chest pain patients undergoing out-of-hours ETT. Eligible patients had a nonischemic ECG, normal 6-12-h ST-segment monitoring, a negative 12-h troponin T assay, and no contraindications to exercise. Observed LOS was compared to expected LOS in the absence of out-of-hours ETT, using Wilcoxon rank-sum test. Estimated bed day savings and major adverse events at 30 days after discharge were examined.

RESULTS

Four hundred and twenty-two patients with a mean age of 52 years (SD 13 years, 25-83 years) were evaluated. Fifty-two per cent (n = 221) were men; 66% (n = 279) had one or less cardiovascular risk factors; and 79% (n = 334) of the patients presented on a Friday or Saturday. ETT was performed on a weekend day in 86% (n = 363) of the patients, facilitating same-day discharges in 71% (n =  300). The median LOS (interquartile range) was 1 day (1, 2 days) for patients assessed with out-of-hours ETT. The expected median LOS (IQR) was 3 days (2, 4 days) (P < 0.05) in the absence of out-of-hours ETT. Each out-of-hours ETT was estimated to save a mean (SD, range) of 1.6 (0.6, 1-4) bed days. Thirty-day mortality and readmission rates were 0 and 0.2% (1 of 422), respectively.

CONCLUSION

The availability of out-of-hours ETT facilitates safe early discharge and reduced LOS for low-to-moderate-risk patients admitted with symptoms of acute coronary syndrome.

High-sensitive troponin T assay for the diagnosis of acute myocardial infarction: an economic evaluation

Background

Delayed diagnosis and treatment of Acute Myocardial Infarction (AMI) has a major adverse impact on prognosis in terms of both morbidity and mortality. Since conventional cardiac Troponin assays have a low sensitivity for diagnosing AMI in the first hours after myocardial necrosis, high-sensitive assays have been developed. The aim of this study was to assess the cost effectiveness of a high-sensitive Troponin T assay (hsTnT), alone or combined with the heart-type fatty acid-binding protein (H-FABP) assay in comparison with the conventional cardiac Troponin (cTnT) assay for the diagnosis of AMI in patients presenting to the hospital with chest pain.

Methods

We performed a cost-utility analysis (quality adjusted life years-QALYs) and a cost effectiveness analysis (life years gained-LYGs) based on a decision analytic model, using a health care perspective in the Dutch context and a life time time-horizon. The robustness of model predictions was explored using one-way and probabilistic sensitivity analyses.

Results

For a life time incremental cost of 30.70 Euros, use of hsTnT over conventional cTnT results in gain of 0.006 Life Years and 0.004 QALY. It should be noted here that hsTnT is a diagnostic intervention which costs only 4.39 Euros/test more than the cTnT test. The ICER generated with the use of hsTnT based diagnostic strategy comparing with the use of a cTnT-based strategy, is 4945 Euros per LYG and 7370 Euros per QALY. The hsTnT strategy has the highest probability of being cost effective at thresholds between 8000 and 20000 Euros per QALY. The combination of hsTnT and h-FABP strategy’s probability of being cost effective remains lower than hsTnT at all willingness to pay thresholds.

Conclusion

Our analysis suggests that hsTnT assay is a very cost effective diagnostic tool relative to conventional TnT assay. Combination of hsTnT and H-FABP does not offer any additional economic and health benefit over hsTnT test alone.

Release kinetics of early ischaemic biomarkers in a clinical model of acute myocardial infarction

Objective

To determine the release kinetics of different biomarkers with potential as novel early ischaemic biomarkers in patients with acute coronary syndrome (ACS); it is difficult to establish the detailed release kinetics in patients with acute myocardial infarction (AMI).

Methods

We analysed the release kinetics of soluble fms-like tyrosine kinase (sFlt-1), ischaemia modified albumin (IMA), and heart-type fatty acid binding protein (hFABP) in patients with hypertrophic obstructive cardiomyopathy who were undergoing transcoronary ablation of septal hypertrophy (TASH), a procedure mimicking AMI. Consecutive patients (n=21) undergoing TASH were included. Blood samples were collected before TASH and 15, 30, 45, 60, 75, 90, and 105 min and 2, 4, 8, and 24 h after TASH. sFlt-1 and hFABP were quantified in serum, and IMA was quantified in plasma using immunoassays.

Results

sFLT-1 and hFABP increased significantly 15 min after induction of AMI vs baseline as follows: sFlt-1, 3657.5 ng/L (IQR 2302.3–4475.0) vs 76.0 ng/L (IQR 71.2–88.8) (p<0.001); hFABP, 9.0 ng/mL (IQR 7.0–15.4) vs 4.6 ng/mL (IQR 3.4–7.1) (p<0.001). sFlt-1 demonstrated a continuous decrease after the 15th min. hFABP showed a continuous increase until the 8th hour with a decline afterwards. The IMA concentrations increased significantly 30 min after induction of AMI vs baseline, with values of 26.0 U/mL (IQR 21.8–38.6) vs 15.6 U/mL (IQR 10.1–24.7) (p=0.02), and then decreased after 75 min.

Conclusions

sFlt-1 and hFABP increased very early after induction of myocardial ischaemia, showing different release kinetics. The additional information provided by these findings is helpful for developing their potential combined use with cardiac troponins in patients with suspected AMI.

Impact of clinical predictors and routine coronary artery disease testing on outcome of patients admitted to chest pain decision unit

BACKGROUND

Chest pain decision unit (CDU) evaluation of patients with acute chest pain (ACP) and nondiagnostic electrocardiogram (ECG) usually includes noninvasive testing for coronary artery disease (CAD).

HYPOTHESIS

CAD evaluation will not improve clinical outcome in low-risk ACP patients.

METHODS

We studied 459 adults admitted to CDU with ACP and no troponin release who underwent noninvasive CAD testing (stress testing in 396 and coronary computed tomographic angiography in 63). Multivariate logistic regression was used to determine predictors of adverse outcome over a 3-year follow-up period.

RESULTS

Initial noninvasive test was normal in 367 (80%) and abnormal (positive or indeterminate) in 92 (20%). A total of 42 (9%) patients underwent invasive coronary angiography, and 16 (3.5%) underwent revascularization. During follow-up, 33 patients had a total of 36 major clinical events: 12 revascularizations, 9 myocardial infarctions, and 15 deaths. Multivariate logistic regression analysis identified abnormal ECG (odds ratio [OR]: 2.7, P = 0.03), typical chest pain (OR: 3.8, P = 0.002), diabetes (OR: 4.1, P = 0.001), and known CAD (OR: 2.3, P = 0.03) as independent predictors for adverse outcome, but not noninvasive test result. Thus, in 187 patients with no high-risk features (41% of the cohort), the annualized event rate was 0.5%. In 272 patients with at least 1 high-risk feature, annualized event rates were 2.8% and 5.7% when noninvasive test was normal or abnormal, respectively (P = 0.04).

CONCLUSIONS

Clinical risk stratification allows identification of patients at low risk of adverse outcome over an intermediate period of follow-up. Noninvasive testing is not warranted in such patients.