Agreement among high-sensitivity cardiac troponin assays and non-invasive testing, clinical outcomes, and quality-of-care outcomes based on the 2020 European Society of Cardiology Guidelines

AIMS

Quality-of-care and safety of patients with suspected acute coronary syndrome (ACS) would benefit if management was independent of which high-sensitivity cardiac troponin (hs-cTn) assay was used for risk stratification. We aimed to determine the concordance of hs-cTn assays to risk-stratify patients with suspected ACS according to the European Society of Cardiology (ESC) 2020 Guidelines.

METHODS AND RESULTS

Blood samples were obtained at arrival and at 2 h from patients with suspected ACS using four hs-cTn assays. The patients were classified into rule-out/observe/rule-in strata based on the ESC 2020 Guidelines. Concordance was determined among the assays for rule-out/observe/rule-in strata. The prevalences of significant underlying disease (≥50% stenosis on coronary computed tomography or inducible myocardial ischaemia on stress testing) and adjudicated ACS, plus quality-of-care outcomes, were compared. Among 238 patients (52.7 ± 8.0 years; 40.3% female), the overall concordance across assays to classify patients into rule-out/observe/rule-in strata was 74.0% (176/238). Platforms significantly differed for rule-out (89.9 vs. 76.5 vs. 78.6 vs. 86.6%, P < 0.001) and observe strata (6.7 vs. 20.6 vs. 17.7 vs. 9.2%, P < 0.001), but not for rule-in strata (3.4 vs. 2.9 vs. 3.8 vs. 4.2%, P = 0.62). Among patients in ruled-out strata, 19.1-21.6% had significant underlying disease and 3.3-4.2% had ACS. The predicted disposition of patients and cost-of-care differed across the assays (all P < 0.001). When compared with observed strata, conventional troponin-based management and predicted quality-of-care outcomes significantly improved with hs-cTn-based strategies (direct discharge: 21.0 vs. 80.3-90.8%; cost-of-care: $3889 ± 4833 vs. $2578 ± 2896-2894 ± 4371, all P < 0.001).

CONCLUSION

Among individuals with suspected ACS, patient management may differ depending on which hs-cTn assay is utilized. More data are needed regarding the implications of inter-assay differences.

TRAIL REGISTRATION

NCT01084239.

Frequency, compliance, and yield of cardiac testing after high-sensitivity troponin accelerated diagnostic protocol implementation

BACKGROUND

Among persons presenting to the emergency department with suspected acute myocardial infarction (MI), cardiac troponin (cTn) testing is commonly used to detect acute myocardial injury. Accelerated diagnostic protocols (ADPs) guide clinicians to integrate cTn results with other clinical information to decide whether to order further diagnostic testing.

OBJECTIVE

To determine the change in the rate and yield of stress test or coronary CT angiogram following cTn measurement in patients with chest pain presenting to the emergency department pre- and post-transition to a high-sensitivity (hs-cTn) assay in an updated ADP.

METHODS

Using electronic health records, we examined visits for chest pain at five emergency departments affiliated with an integrated academic health system 1-year pre- and post-hs-cTn assay transition. Outcomes included stress test or coronary imaging frequency, ADP compliance among those with additional testing, and diagnostic yield (ratio of positive tests to total tests).

RESULTS

There were 7564 patient-visits for chest pain, including 3665 in the pre- and 3899 in the post-period. Following the updated ADP using hs-cTn, 862 (23.5 per 100 patient visits) visits led to subsequent testing versus 1085 (27.8 per 100 patient visits) in the pre-hs-cTn period, (P < 0.001). Among those who were tested, the protocol-compliant rate fell from 80.9% to 46.5% (P < 0.001), but the yield of those tests rose from 24.5% to 29.2% (P = 0.07). Among tests that were noncompliant with ADP guidance, yield was similar pre- and post-updated hs-cTn ADP implementation (pre 13.0%, post 15.4% (P = 0.43).

CONCLUSION

Implementation of hs-cTn supported by an updated ADP was associated with a lower rate of stress testing and coronary CT angiogram.

Deep Learning Analysis of Chest Radiographs to Triage Patients with Acute Chest Pain Syndrome

Background Patients presenting to the emergency department (ED) with acute chest pain (ACP) syndrome undergo additional testing to exclude acute coronary syndrome (ACS), pulmonary embolism (PE), or aortic dissection (AD), often yielding negative results. Purpose To assess whether deep learning (DL) analysis of the initial chest radiograph may help triage patients with ACP syndrome more efficiently. Materials and Methods This retrospective study used electronic health records of patients with ACP syndrome at presentation who underwent a combination of chest radiography and additional cardiovascular or pulmonary imaging or stress tests at two hospitals (Massachusetts General Hospital [MGH], Brigham and Women's Hospital [BWH]) between January 2005 and December 2015. A DL model was trained on 23 005 patients from MGH to predict a 30-day composite end point of ACS, PE, AD, and all-cause mortality based on chest radiographs. Area under the receiver operating characteristic curve (AUC) was used to compare performance between models (model 1: age + sex; model 2: model 1 + conventional troponin or d-dimer positivity; model 3: model 2 + DL predictions) in internal and external test sets from MGH and BWH, respectively. Results At MGH, 5750 patients (mean age, 59 years ± 17 [SD]; 3329 men, 2421 women) were evaluated. Model 3, which included DL predictions, significantly improved discrimination of those with the composite outcome compared with models 2 and 1 (AUC, 0.85 [95% CI: 0.84, 0.86] vs 0.76 [95% CI: 0.74, 0.77] vs 0.62 [95% CI: 0.60 0.64], respectively; P < .001 for all). When using a sensitivity threshold of 99%, 14% (813 of 5750) of patients could be deferred from cardiovascular or pulmonary testing for differential diagnosis of ACP syndrome using model 3 compared with 2% (98 of 5750) of patients using model 2 (P < .001). Model 3 maintained its diagnostic performance in different age, sex, race, and ethnicity groups. In external validation at BWH (22 764 patients; mean age, 57 years ± 17; 11 470 women), trends were similar and improved after fine tuning. Conclusion Deep learning analysis of chest radiographs may facilitate more efficient triage of patients with acute chest pain syndrome in the emergency department. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Goo in this issue.

Development of a unified national database of primary percutaneous coronary intervention centers with co-located emergency departments, 2020

BACKGROUND

Although primary percutaneous coronary intervention (pPCI) is the preferred intervention for ST-elevation myocardial infarction (STEMI), not all patients are admitted directly to an emergency department (ED) with 24/7/365 pPCI capabilities. This is partly due to a lack of a national system of known pPCI-capable EDs. Our objective was to create a unified, national database of confirmed 24/7/365 pPCI centers co-located in hospitals with EDs.

METHODS

We compiled all hospitals designated as Chest Pain Centers with Primary PCI by the American College of Cardiology's (ACC) National Clinical Data Registry (NCDR), all STEMI Receiving Centers designated by the American Heart Association's (AHA) Mission: Lifeline registry, and all state-designated pPCI-capable hospitals and designation criteria from state departments of health. We matched ACC, AHA, and state-designated facilities to those in the 2019 National ED Inventory (NEDI)-USA database to identify all EDs in pPCI-capable hospitals.

RESULTS

Overall, 467 hospitals were recognized as Chest Pain Centers with Primary PCI by ACC, 293 hospitals were recognized as being STEMI Receiving Centers by AHA, and 827 hospitals were confirmed to be pPCI-capable by state designations and operated 24/7/365. Together, there were 1,178 EDs (21% of 5,587 total) co-located in pPCI-capable hospitals operating 24/7/365.

CONCLUSIONS

There is substantial heterogeneity in cardiac systems of care, with large regional systems existing alongside local state-led initiatives. We created a unified national database of confirmed 24/7/365 pPCI centers co-located in hospitals with EDs. This data set will be valuable for future cardiac systems research and improving access to pPCI.

Agreement between four high-sensitivity cardiac troponin assays and non-invasive testing, clinical and quality of care outcomes based on the 2020 ESC guidelines: results from the ROMICAT II trial

Background

Quality of care and safety of patients with suspected acute coronary syndrome (ACS) would greatly benefit if management was independent of which high-sensitivity cardiac troponin (hs-cTn) assay was used for risk stratification.

Purpose

To assess the agreement of 4 hs-cTn assays to risk stratify patients with suspected ACS using the ESC2020 Guidelines 0/2-hour algorithm, and to assess their associations with non-invasive diagnostic testing, clinical- and quality of care outcomes.

Methods

We analyzed blood samples obtained at emergency department (ED) presentation and 2 hours later from patients with suspected ACS enrolled in the ROMICAT (Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography) II trial, using 4 hs-cTn assays (Roche Diagnostics, Elecsys 2010; Abbott Diagnostics, ARCHITECT i2000SR; Siemens Diagnostics, HsVista; Beckman Coulter, ACCESS). We determined the agreement between the assays to assign patients to rule-out, observe, and rule-in management pathways according to the ESC2020 Guidelines. Further, we assessed assay association with non-invasive diagnostic test findings and adjudicated clinical- and quality of care outcomes. Finally, we compared observed conventional troponin management with predicted management per ESC2020 guidelines using hs-cTn assays.

Results

Overall, assignment to ESC2020 Guideline management pathways among 238 patients with suspected ACS (age 52.7±8.0 years; 40.3% [96/238] female) was concordant across all hs-Tn assays in 74% of patients but differed for rule-out rates (89.9% vs 76.5% vs 78.6% vs 86.6%, p&lt;0.001) and observation rates (6.7% vs 20.6% vs 17.7% vs 9.2%, p&lt;0.001), but not for rule-in (3.4% vs 2.9% vs 3.8% vs 4.2%, p=0.623). Among those whose management recommendation was rule-out, 19.1–21.6% had obstructive CAD defined as coronary stenosis ≥50% on coronary CT angiography or inducible myocardial ischemia on perfusion imaging and 3.3–4.2% were diagnosed with ACS as adjudicated by independent panel. Predicted ED discharge rates based on hs-cTn assays were higher than those observed with conventional troponin (80.3% to 90.8% vs. 21.0%, respectively p&lt;0.001). As a result, predicted costs of care were significantly lower based on strategies utilizing hs-cTn assays than with conventional troponin ($2,578±2,896 to $2,894±4,371 vs $3,889±4,833, respectively, p&lt;0.001)

Conclusion

In a quarter of patients presenting to the ED with suspected ACS ESC2020 Guideline-based management may be different, depending on the hs-cTn assay. As compared to conventional troponin, hs-cTn is predicted to significantly increase direct ED discharges and lower costs of care.

Funding Acknowledgement

Type of funding sources: None.

Finding acute coronary syndrome with serial troponin testing for rapid assessment of cardiac ischemic symptoms (FAST-TRAC): a study protocol

Objective

To determine the utility of a highly sensitive troponin assay when utilized in the emergency department.

Methods

The FAST-TRAC study prospectively enrolled >1,500 emergency department patients with suspected acute coronary syndrome within 6 hours of symptom onset and 2 hours of emergency department presentation. It has several unique features that are not found in the majority of studies evaluating troponin. These include a very early presenting population in whom prospective data collection of risk score parameters and the physician’s clinical impression of the probability of acute coronary syndrome before any troponin data were available. Furthermore, two gold standard diagnostic definitions were determined by a pair of cardiologists reviewing two separate data sets; one that included all local troponin testing results and a second that excluded troponin testing so that diagnosis was based solely on clinical grounds. By this method, a statistically valid head-to-head comparison of contemporary and high sensitivity troponin testing is obtainable. Finally, because of a significant delay in sample processing, a unique ability to define the molecular stability of various troponin assays is possible.

Trial registration

ClinicalTrials.gov Identifier NCT00880802

Multiple Cardiac Biomarker Testing Among Patients With Acute Dyspnea From the ICON-RELOADED Study

BACKGROUND

Among patients with acute dyspnea, concentrations of N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity cardiac troponin T, and insulin-like growth factor binding protein-7 predict cardiovascular outcomes and death. Understanding the optimal means to interpret these elevated biomarkers in patients presenting with acute dyspnea remains unknown.

METHODS AND RESULTS

Concentrations of NT-proBNP, high-sensitivity cardiac troponin T, and insulin-like growth factor binding protein-7 were analyzed in 1448 patients presenting with acute dyspnea from the prospective, multicenter International Collaborative of NT-proBNP-Re-evaluation of Acute Diagnostic Cut-Offs in the Emergency Department (ICON-RELOADED) Study. Eight biogroups were derived based upon patterns in biomarker elevation at presentation and compared for differences in baseline characteristics. Of 441 patients with elevations in all 3 biomarkers, 218 (49.4%) were diagnosed with acute heart failure (HF). The frequency of acute HF diagnosis in this biogroup was higher than those with elevations in 2 biomarkers (18.8%, 44 of 234), 1 biomarker (3.8%, 10 of 260), or no elevated biomarkers (0.4%, 2 of 513). The absolute number of elevated biomarkers on admission was prognostic of the composite end point of mortality and HF rehospitalization. In adjusted models, patients with one, 2, and 3 elevated biomarkers had 3.74 (95% confidence interval [CI], 1.26-11.1, P = .017), 12.3 (95% CI, 4.60-32.9, P < .001), and 12.6 (95% CI, 4.54-35.0, P < .001) fold increased risk of 180-day mortality or HF rehospitalization.

CONCLUSIONS

A multimarker panel of NT-proBNP, hsTnT, and IGBFP7 provides unique clinical, diagnostic, and prognostic information in patients presenting with acute dyspnea. Differences in the number of elevated biomarkers at presentation may allow for more efficient clinical risk stratification of short-term mortality and HF rehospitalization.

Diagnostic and Prognostic Utilities of Insulin-Like Growth Factor Binding Protein-7 in Patients With Dyspnea

OBJECTIVES

This study examined whether insulin-like growth factor binding protein-7 (IGFBP7) would aid in the diagnosis and prognosis of acute heart failure (HF) beyond N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration.

BACKGROUND

IGFBP7 is associated with impaired ventricular relaxation and worse prognosis.

METHODS

The ICON-RELOADED (International Collaborative of NT-proBNP-Re-evaluation of Acute Diagnostic Cut-Offs in the Emergency Department) study was a prospective, multicenter clinical trial that enrolled subjects presenting with dyspnea. Six-month prognosis for death or repeat hospitalization was obtained.

RESULTS

Among 1,449 patients, 274 (18.9%) were diagnosed with acute HF. Those with IGFBP7 concentrations in the highest quartile were older, male, had hypertension and HF, had lower estimated glomerular filtration rate (eGFR) and lowest ejection fraction (41 ± 20%; all p < 0.001). Independent predictors of IGFBP7 were age, male sex, history of diabetes, history of HF, and eGFR. Median concentrations of NT-proBNP (2,844 ng/ml vs. 99 ng/ml) and IGFBP7 (146.1 ng/ml vs. 86.1 ng/ml) were higher in those with acute HF (both; p < 0.001). Addition of IGFBP7 to NT-proBNP concentrations improved discrimination, therefore increasing the area under the receiver operating curve for diagnosis of acute HF (from 0.91 to 0.94; p < 0.001 for differences). Addition of IGFBP7 to a complete model of independent predictors of acute HF improved model calibration. IGFBP7 significantly reclassified acute HF diagnosis beyond NT-proBNP (net reclassification index: +0.25). Higher log₂-IGFBP7 concentrations in patients with acute HF predicted death or rehospitalization at 6 months (hazard ratio: 1.84 per log₂-SD; 95% confidence interval: 1.30 to 2.61; p = 0.001). In Kaplan-Meier analyses, supramedian concentrations of IGFBP7 were associated with shorter event-free survival (log-rank: p < 0.001).

CONCLUSIONS

Among patients with acute dyspnea, concentrations of IGFBP7 add to NT-proBNP for diagnosis of acute HF and provide added prognostic utility for short-term risk.

Discordance of High-Sensitivity Troponin Assays in Patients With Suspected Acute Coronary Syndromes

BACKGROUND

High-sensitivity cardiac troponin (hs-cTn) assays have different analytic characteristics.

OBJECTIVES

The goal of this study was to quantify differences between assays for common analytical benchmarks and to determine whether they may result in differences in the management of patients with suspected acute coronary syndrome (ACS).

METHODS

The authors included patients with suspected ACS enrolled in the ROMICAT (Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography) I and II trials, with blood samples taken at emergency department presentation (ROMICAT-I and -II) or at 2 and 4 h thereafter (ROMICAT-II). hs-cTn concentrations were measured using 3 assays (Roche Diagnostics, Elecsys 2010 platform; Abbott Diagnostics, ARCHITECT i2000SR; Siemens Diagnostics, HsVista). Per blood sample, we determined concordance across analytic benchmarks (99th percentile). Per-patient, the authors determined concordance of management recommendations (rule-out/observe/rule-in) per the 0/2-h algorithm, and their association with diagnostic test findings (coronary artery stenosis >50% on coronary computed tomography angiography or inducible ischemia on perfusion imaging) and ACS.

RESULTS

Among 1,027 samples from 624 patients (52.8 ± 10.0 years; 39.4% women), samples were classified as 99th percentile (7.2% vs. 6.0% vs. 6.2%) by Roche, Abbott, and Siemens, respectively. A total of 37.4% (n = 384 of 1,027) of blood samples were classified into the same analytical benchmark category, with low concordance across benchmarks (99th percentile 43.6%). Serial samples were available in 242 patients (40.1% women; mean age: 52.8 ± 8.0 years). The concordance of management recommendations across assays was 74.8% (n = 181 of 242) considering serial hs-cTn measurements. Of patients who were recommended to discharge, 19.6% to 21.1% had positive diagnostic test findings and 2.8% to 4.3% had ACS at presentation.

CONCLUSIONS

Caregivers should be aware that there are significant differences between hs-cTn assays in stratifying individual samples and patients with intermediate likelihood of ACS according to analytical benchmarks that may result in different management recommendations. (Rule Out Myocardial Infarction by Computer Assisted Tomography [ROMICAT]; NCT00990262) (Multicenter Study to Rule Out Myocardial Infarction by Cardiac Computed Tomography [ROMICAT-II]; NCT01084239).

Echocardiographic assessment of insulin-like growth factor binding protein-7 and early identification of acute heart failure

Aims

Concentrations of insulin‐like growth factor binding protein‐7 (IGFBP7) have been linked to abnormal cardiac structure and function in patients with chronic heart failure (HF), but cardiovascular correlates of the biomarker in patients with more acute presentations are lacking.

We aimed to determine the relationship between IGFBP7 concentrations and cardiac structure and to evaluate the impact of IGFBP7 on the diagnosis of acute HF among patients with acute dyspnoea.

Methods and results

In this pre‐specified subgroup analysis of the International Collaborative of N‐terminal pro‐B‐type Natriuretic Peptide Re‐evaluation of Acute Diagnostic Cut‐Offs in the Emergency Department (ICON‐RELOADED) study, we included 271 patients with and without acute HF. All patients presented to an emergency department with acute dyspnoea, had blood samples for IGFBP7 measurement, and detailed echocardiographic evaluation.

Higher IGFBP7 concentrations were associated with numerous cardiac abnormalities, including increased left atrial volume index (LAVi; r = 0.49, P < 0.001), lower left ventricular ejection fraction (r = −0.27, P < 0.001), lower right ventricular fractional area change (r = −0.31, P < 0.001), and higher tissue Doppler E/e′ ratio (r = 0.44, P < 0.001). In multivariable linear regression analyses, increased LAVi (P = 0.01), lower estimated glomerular filtration rate (P = 0.008), higher body mass index (P = 0.001), diabetes (P = 0.009), and higher concentrations of amino‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP, P = 0.02) were independently associated with higher IGFBP7 concentrations regardless of other variables. Furthermore, IGFBP7 (odds ratio = 12.08, 95% confidence interval 2.42–60.15, P = 0.02) was found to be independently associated with the diagnosis of acute HF in the multivariable logistic regression analysis.

Conclusions

Among acute dyspnoeic patients with and without acute HF, increased IGFBP7 concentrations are associated with a range of cardiac structure and function abnormalities. Independent association with increased LAVi suggests elevated left ventricular filling pressure is an important trigger for IGFBP7 expression and release. IGFBP7 may enhance the diagnosis of acute HF.

Long-term health outcomes and cost-effectiveness of coronary CT angiography in patients with suspicion for acute coronary syndrome

BACKGROUND

Randomized trials have shown favorable clinical outcomes for coronary CT angiography (CTA) in patients with suspected acute coronary syndrome (ACS). Our goal was to estimate the cost-effectiveness of coronary CTA as compared to alternative management strategies for ACP patients over lifetime.

METHODS

Markov microsimulation model was developed to compare cost-effectiveness of competitive strategies for ACP patients: 1) coronary CTA, 2) standard of care (SOC), 3) AHA/ACC Guidelines, and 4) expedited emergency department (ED) discharge protocol with outpatient testing. ROMICAT-II trial was used to populate the model with low to intermediate risk of ACS patient data, whereas diagnostic test-, treatment effect-, morbidity/mortality-, quality of life- and cost data were obtained from the literature. We predicted test utilization, costs, 1-, 3-, 10-year and over lifetime cardiovascular morbidity/mortality for each strategy. We determined quality adjusted life years (QALY) and incremental cost-effectiveness ratio. Observed outcomes in ROMICAT-II were used to validate the short-term model.

RESULTS

Estimated short-term outcomes accurately reflected observed outcomes in ROMICAT-II as coronary CTA was associated with higher costs ($4,490 vs. $2,513-$4,144) and revascularization rates (5.2% vs. 2.6%-3.7%) compared to alternative strategies. Over lifetime, coronary CTA dominated SOC and ACC/AHA Guidelines and was cost-effective compared to expedited ED protocol ($49,428/QALY). This was driven by lower cardiovascular mortality (coronary CTA vs. expedited discharge: 3-year: 1.04% vs. 1.10-1.17; 10-year: 5.06% vs. 5.21-5.36%; respectively).

CONCLUSION

Coronary CTA in patients with suspected ACS renders affordable long-term health benefits as compared to alternative strategies.

3303Classification of patients with acute chest pain by analytical benchmarks and subsequent management recommendations - A comparison of three highly-sensitivity troponin assays in the ROMICAT trials

Background

Concordance of different highly-sensitive troponin (hsTn) assays in stratifying acute chest pain (ACP) patients according to analytical benchmarks and subsequent emergency department (ED) management recommendations are unknown.

Methods

We included patients enrolled in the ROMICAT (Rule Out Myocardial Infarction/Ischemia Using Computer-Assisted Tomography) I and II trials (n=624; 39.1% female; 52.8±10.0 years), who presented to the ED and were referred to further non-invasive diagnostic testing. In ROMICAT I, blood was obtained at 4 hours, and in ROMICAT II at ED presentation, and at 2 and 4 hours and was tested with three state-of-the-art hsTn assays (Roche Diagnostics, Elecsys 2010; Abbott ARCHITECT i2000SR; Siemens Diagnostics, HsVista). In a per sample analysis, we compared the concordance of assays for analytic benchmarks (below the level of detection (LOD)/LOD to 99th percentile/99th percentile to myocardial infarction (<LOD], ><LOD], >MI)/above MI). In a per patient analysis of serial hsTn testing in ROMICAT II, we determined concordance of management recommendations (rule out/observe/rule in) based on 2015ESC guidelines, results of coronary CT angiography and stress myocardial perfusion, and adjudicated endpoints of ACS.

Results

Overall, only 34.4% (353/1027) of samples were classified into the same benchmark category by all assays (table 1). In a per patient analysis, all assays agreed on the same of management recommendation in 25.3% (49/242) patients after the 1st hsTn, mostly driven by differences in discharge (6.6%, 21.1%, and 61.2%; respectively; all p<0.001). The concordance of management recommendations improved significantly to 67.4% (163/242; p<0.001) after the 2nd hsTn measurement but the final agreement for “observe” and “rule in” remained limited (13/90 and 5/18). Among patients in whom discharge was recommended, at least 18.8% (range: 18.8–21.0% across assays) had a positive imaging/stress test and at least 2.9% (range: 2.9–3.4%) had ACS.

Table 1. Classification of measurements from three hsTn assays in 1027 samples of patients with ACP according to analytical benchmarks <LOD LOD – 99th %tile* 99th %tile* – AMI** AMI**< Roche Elecsys, n (%) 578 (56.3) 328 (31.9) 95 (9.3) 26 (2.5) Abbott ARCHITECT, n (%) 176 (17.1) 788 (76.7) 14 (1.7) 49 (4.8) Siemens Vista, n (%) 96 (9.4) 861 (83.9) 33 (3.2) 37 (3.6) *Assay specific 99th percentiles; **as per ESC 2015 guidelines.

Conclusion

Differences in hsTn assay concordance for analytical benchmarks and subsequent ED management recommendations in patients with ACP are substantial raising concerns about the lack of uniform management.

Acknowledgement/Funding

Fulbright Visiting Student Researcher Grant

P5005Diagnostic and prognostic utilities of insulin-like growth factor-binding protein-7 in patients presenting to the emergency department with dyspnea: results from the ICON-RELOADED study

Background

Increased activity of insulin-like growth factor–binding protein-7 (IGFBP7) is associated with cellular senescence, tissue aging, and obesity. Prior studies in chronic heart failure (HF) have linked IGFBP7 to impaired myocardial relaxation. The role of IGFBP7 measurement in acute HF remains unclear.

Purpose

To examine whether concentrations of IGFBP7 in patients presenting with dyspnea to the emergency department (ED) will aid in the diagnosis and prognosis of acute HF beyond N-terminal pro- B type natriuretic peptide (NT-proBNP).

Methods

The ICON-RELOADED (International Collaborative of NT-proBNP- Re-evaluation of Acute Diagnostic Cut-Offs in the Emergency Department) study was a prospective, multicenter clinical trial conducted at 19 sites in North America that enrolled subjects ≥22 years of age presenting to ED with complaints of dyspnea. Subjects were blindly adjudicated for the diagnosis of acute HF. A blood sample was taken at enrollment. Six-month prognosis for death/repeat hospitalization was obtained. IGFBP7 was measured using a pre-clinical research use only assay.

Results

Among 1449 patients (n=274 with acute HF), those with IGFBP7 concentrations in the highest quartile (>123.7 ng/mL) were older, more likely to be male and to have a history of hypertension and HF (all p<0.001). They also had lower estimated glomerular filtration rate (eGFR) and the lowest left ventricular ejection fraction (41% ± 21%) prior to study enrollment (all p<0.001). Independent predictors of IGFBP7 included age, male sex, history of diabetes, history of HF, and eGFR (all p<0.001). Median concentrations of NT-proBNP (2844 vs. 99 ng/mL) and IGFBP7 (146.1 vs. 86.1 ng/mL) were significantly higher in those with acute HF (both p<0.001); addition of IGFBP7 to NT-proBNP concentrations improved discrimination, increasing the area under the receiver operating curve for diagnosis of acute HF (from 0.91 to 0.94; p<0.001) (Figure 1). Addition of IGFBP7 to a complete model of independent predictors of acute HF (including NT-proBNP) improved model calibration; IGFBP7 also significantly re-classified acute HF diagnosis beyond NT-proBNP alone (net reclassification improvement +0.25; p<0.001). Higher log2-IGFBP7 concentrations predicted death/rehospitalization at 6 months (hazard ratio 1.74 per log2-standard deviation, 95% confidence interval 1.26–2.40, p=0.001). In Kaplan-Meier analyses, supramedian concentrations of IGFBP7 were associated with shorter event-free survival (log-rank p<0.001).

ROC curve for diagnosis of acute HF

Conclusions

Among patients with acute dyspnea, concentrations of IGFBP7 add to NT-proBNP for diagnosis of acute HF and provide added prognostic utility for short-term risk.

Acknowledgement/Funding

Funding for this study was provided by Roche Diagnostics (Risch-Rotkreuz, Switzerland).

Utilization of stress testing for low-risk patients with chest discomfort in the emergency department

BACKGROUND

The management of patients presenting to an emergency department with chest discomfort at low-risk for acute coronary syndrome represents a common clinical challenge. Such patients are often triaged to chest pain units for monitoring and cardiac stress testing for further risk stratification.

METHODS

We conducted a retrospective study of 292 low-risk patients who presented to an emergency department with chest discomfort. We performed physician-adjudicated chart reviews of all patients with positive stress tests to assess downstream testing, subsequent coronary revascularization, and outcomes.

RESULTS

Of the 292 patients, 33 (11.3%) had stress tests positive for ischemia, and 12 (4.1%) underwent diagnostic cardiac catheterization. Of the 292 patients, 4 (1.4%) underwent coronary revascularization that may have resulted in a mortality benefit.

CONCLUSION

These data suggest a very low yield of detecting clinically significant coronary disease with stress testing low-risk patients with chest discomfort in emergency department chest pain units.

N-Terminal Pro-B-Type Natriuretic Peptide in the Emergency Department: The ICON-RELOADED Study

BACKGROUND

Contemporary reconsideration of diagnostic N-terminal pro-B-type natriuretic peptide (NT-proBNP) cutoffs for diagnosis of heart failure (HF) is needed.

OBJECTIVES

This study sought to evaluate the diagnostic performance of NT-proBNP for acute HF in patients with dyspnea in the emergency department (ED) setting.

METHODS

Dyspneic patients presenting to 19 EDs in North America were enrolled and had blood drawn for subsequent NT-proBNP measurement. Primary endpoints were positive predictive values of age-stratified cutoffs (450, 900, and 1,800 pg/ml) for diagnosis of acute HF and negative predictive value of the rule-out cutoff to exclude acute HF. Secondary endpoints included sensitivity, specificity, and positive (+) and negative (-) likelihood ratios (LRs) for acute HF.

RESULTS

Of 1,461 subjects, 277 (19%) were adjudicated as having acute HF. The area under the receiver-operating characteristic curve for diagnosis of acute HF was 0.91 (95% confidence interval [CI]: 0.90 to 0.93; p < 0.001). Sensitivity for age stratified cutoffs of 450, 900, and 1,800 pg/ml was 85.7%, 79.3%, and 75.9%, respectively; specificity was 93.9%, 84.0%, and 75.0%, respectively. Positive predictive values were 53.6%, 58.4%, and 62.0%, respectively. Overall LR+ across age-dependent cutoffs was 5.99 (95% CI: 5.05 to 6.93); individual LR+ for age-dependent cutoffs was 14.08, 4.95, and 3.03, respectively. The sensitivity and negative predictive value for the rule-out cutoff of 300 pg/ml were 93.9% and 98.0%, respectively; LR- was 0.09 (95% CI: 0.05 to 0.13).

CONCLUSIONS

In acutely dyspneic patients seen in the ED setting, age-stratified NT-proBNP cutpoints may aid in the diagnosis of acute HF. An NT-proBNP <300 pg/ml strongly excludes the presence of acute HF.

Preventive Management of Nonobstructive CAD After Coronary CT Angiography in the Emergency Department

OBJECTIVES

This study sought to assess medical management of patients found to have nonobstructive coronary artery disease (CAD) on coronary computed tomography angiography (CCTA) performed in the emergency department (ED).

BACKGROUND

Contemporary recognition and management of nonobstructive CAD discovered on CCTA performed in the ED is unknown.

METHODS

Patients undergoing CCTA in the authors' hospital's ED between November 2013 and March 2018 who also received primary care within the authors' health system were studied. All patients with nonobstructive CAD, defined as 1% to 49% maximum luminal stenosis on CCTA, were included, along with a control group without CAD in a 1 case:1 control fashion. Ten-year atherosclerotic cardiovascular disease (ASCVD) risk prior to CCTA was estimated using the Pooled Cohort Equations. Management changes were recorded until 6 months after CCTA. Multivariate logistic regression tested the association between CCTA result and follow-up statin prescription, adjusting for cardiovascular risk factors and baseline statin use.

RESULTS

The cohort included 510 patients with nonobstructive CAD and 510 controls. Prevalence of statin prescription increased from 38.8% to 56.1% among patients with nonobstructive CAD (p < 0.001) and 18.0% to 20.4% among controls (p = 0.01), representing a 7.1-fold relative difference (95% confidence interval [CI]: 4.4 to 23.0; p < 0.001) in multivariate analysis. However, 30.0% of patients with nonobstructive CAD and ≥20% 10-year ASCVD risk were not prescribed a statin at the end of follow-up. Cardiologist evaluation was independently associated with statin prescription after adjustment for ASCVD risk factors (odds ratio [OR] 4.4; 95% CI: 2.4 to 8.5; p < 0.001). A Coronary Artery Disease Reporting and Data System class 1 to 2 result was associated with lower low-density lipoprotein cholesterol by 12.1 mg/dl at mean 1.9-year follow-up (p < 0.001).

CONCLUSIONS

Incidental subclinical atherosclerosis on CCTA performed in the ED increases the likelihood of statin prescription, but opportunities to improve allocation of indicated preventive therapies remain.

Non-invasive fractional flow reserve derived from coronary computed tomography angiography in patients with acute chest pain: Subgroup analysis of the ROMICAT II trial

BACKGROUND

Non-invasive fractional flow reserve (FFR_CT) derived from coronary computed tomography angiography (CTA) permits hemodynamic evaluation of coronary stenosis and may improve efficiency of assessment in stable chest pain patients. We determined feasibility of FFR_CT in the population of acute chest pain patients and assessed the relationship of FFR_CT with outcomes of acute coronary syndrome (ACS) and revascularization and with plaque characteristics.

METHODS

We included 68 patients (mean age 55.8 ± 8.4 years, 71% men) from the ROMICAT II trial who had ≥50% stenosis on coronary CTA or underwent additional non-invasive stress test. We evaluated coronary stenosis and high-risk plaque on coronary CTA. FFR_CT was measured in a core laboratory.

RESULTS

We found correlation between anatomic severity of stenosis and FFR_CT ≤0.80 vs. FFR_CT >0.80 (severe stenosis 84.8% vs. 15.2%; moderate stenosis 33.3% vs. 66.7%; mild stenosis 33.3% vs. 66.7% patients). Patients with severe stenosis had lower FFR_CT values (median 0.64, 25th-75th percentile 0.50-0.75) as compared to patients with moderate (median 0.84, 25th-75th percentile, p < 0.001) or mild stenosis (median 0.86, 25th-75th percentile 0.78-0.88, p < 0.001). The relative risk of ACS and revascularization in patients with positive FFR_CT ≤0.80 was 4.03 (95% CI 1.56-10.36) and 3.50 (95% CI 1.12-10.96), respectively. FFR_CT ≤0.80 was associated with the presence of high-risk plaque (odds ratio 3.91, 95% CI 1.55-9.85, p = 0.004) after adjustment for stenosis severity.

CONCLUSION

Abnormal FFR_CT was associated with the presence of ACS, coronary revascularization, and high-risk plaque. FFR_CT measurements correlated with anatomic severity of stenosis on coronary CTA and were feasible in population of patients with acute chest pain.

Secondary cardiac risk stratifying tests after coronary computed tomography angiography in emergency department patients

BACKGROUND

Several large trials demonstrated that coronary computed tomography angiography (CTA) in a triage strategy could lead to increased secondary cardiac risk stratifying testing (SCRST). Whether this is true for routine clinical care remains unclear. We measured SCRSTs after coronary CTA was implemented in our emergency department (ED) practice by CTA result, and if locally existing management recommendations for a structured post CTA diagnostic strategy were followed.

METHODS

This single site retrospective cohort study included all our ED patients who received coronary CTA between October 1, 2012 and September 30, 2016. SCRST's included functional cardiac tests and invasive coronary angiography (ICA), performed during the ED coronary CTA visit or related admission.

RESULTS

A total of 1916 subjects were included with a mean age of 52.9 ± 10.8 years. Of their coronary CTAs, 179 were positive (severe stenosis, occlusion or ventricular wall motion abnormalities; 9.3%), 105 intermediate (moderate stenosis; 5.5%), 1611 negative (no to mild obstructive CAD; 84.1%) and 21 non-diagnostic (1.1%). SCRSTs were performed in 237 (overall 12.4%, noninvasive in 5.6%, ICA in 6.7%). After positive coronary CTA, 73.7% of subjects received SCRSTs. For intermediate, negative and non-diagnostic CTAs this was 72.4%, 1.1% and 47.6% respectively. Management conformed to local management recommendations in 96.2% of cases.

CONCLUSION

In spite of previous trials, rates of secondary cardiac risk stratifying tests after routine clinical ED coronary CTA are low, especially in patients with negative coronary CTA. Structured management guidelines for post coronary CTA, and adherence to these guidelines, appear essential.

Copeptin to rule out myocardial infarction in Blacks versus Caucasians

Background:

Copeptin in combination with troponin has been shown to have incremental value for the early rule-out of myocardial infarction, but its performance in Black patients specifically has never been examined. In light of a potential for wider use, data on copeptin in different relevant cohorts are needed. This is the first study to determine whether copeptin is equally effective at ruling out myocardial infarction in Black and Caucasian races.

Methods:

This analysis of the CHOPIN trial included 792 Black and 1075 Caucasian patients who presented to the emergency department with chest pain and had troponin-I and copeptin levels drawn.

Results:

One hundred and forty-nine patients were diagnosed with myocardial infarction (54 Black and 95 Caucasian). The negative predictive value of copeptin at a cut-off of 14 pmol/l (as in the CHOPIN study) for myocardial infarction was higher in Blacks (98.0%, 95% confidence interval (CI) 96.2–99.1%) than Caucasians (94.1%, 95% CI 92.1–95.7%). The sensitivity at 14 pmol/l was higher in Blacks (83.3%, 95% CI 70.7–92.1%) than Caucasians (53.7%, 95% CI 43.2–64.0%). After controlling for age, hypertension, heart failure, chronic kidney disease and body mass index in a logistic regression model, the interaction term had a P value of 0.03. A cut-off of 6 pmol/l showed similar sensitivity in Caucasians as 14 pmol/l in Blacks.

Conclusions:

This is the first study to identify a difference in the performance of copeptin to rule out myocardial infarction between Blacks and Caucasians, with increased negative predictive value and sensitivity in the Black population at a cut-off of 14 pmol/l. This also holds true for non-ST-segment elevation myocardial infarction and, although numbers were small, similar trends exist in the normal troponin population. This may have significant implications for early rule-out strategies using copeptin.

Identification of coronary artery calcification can optimize risk stratification in patients with acute chest pain

BACKGROUND

The number of patients presenting to the emergency department (ED) with suspected acute coronary syndrome (ACS) is substantial. We tested whether identification of coronary artery calcium (CAC) can improve the negative predictive value (NPV) of clinical risk assessment for ACS in patients with acute chest pain.

METHODS AND RESULTS

We included 826 consecutive patients (mean age: 53±11years; 42% female) without known coronary artery disease (CAD) or initially elevated serum biomarkers, whom underwent non-contrast CT, to assess the CAC score, and CT angiography (CTA), to detect coronary stenosis. We analyzed the diagnostic performance of CAC and the Thrombolysis In Myocardial Infarction (TIMI) risk score for our primary outcomes (ACS and obstructive CAD). No CAC was found in 54% (n=444) of all patients, 63% (n=524) had a TIMI score of 0 and 40% (n=328) had both. The prevalence of obstructive CAD was 16% for ≥50% stenosis and 8.7% for ≥70% stenosis. The incidence of ACS was 7.9%, (MI=11, UAP=54). The NPV of CAC=0 was 99.5% for ACS. The NPV of a combination of TIMI score=0 and no CAC was 89% for any CAD (any plaque or stenosis) and 99.7% for ≥50% stenosis. A 100% NPV was found for ≥70% stenosis and ACS, correctly identifying 328 (40%) patients.

CONCLUSIONS

The exclusion of CAC, in combination with clinical risk assessment, has high clinical value in patients with acute chest pain, as it identifies patients at low risk for ACS and obstructive CAD more accurately as compared to clinical risk assessment alone.

High-Sensitivity Cardiac Troponin I as a Gatekeeper for Coronary Computed Tomography Angiography and Stress Testing in Patients with Acute Chest Pain

BACKGROUND

Most patients presenting to the emergency department (ED) with suspected acute coronary syndrome (ACS) undergo noninvasive cardiac testing with a low diagnostic yield. We determined whether a combination of high-sensitivity cardiac troponin I (hs-cTnI) and cardiovascular risk factors might improve selection of patients for cardiac testing.

METHODS

We included patients from the Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography (ROMICAT) I and II trials who presented to the ED with acute chest pain and were referred for cardiac testing. Based on serial hs-cTnI measurements and cardiovascular risk factors, we derived and validated the criterion for no need of cardiac testing. We predicted the effect of this criterion on the effectiveness of patient management.

RESULTS

A combination of baseline hs-cTnI (<4 ng/L) and cardiovascular risk factors (<2) ruled out ACS with a negative predictive value of 100% in ROMICAT I. We validated this criterion in ROMICAT II, identifying 29% patients as not needing cardiac testing. An additional 5% of patients were identified by adding no change or a decrease between baseline and 2 h hs-cTnI as a criterion. Assuming those patients would be discharged from the ED without cardiac testing, implementation of hs-cTnI would increase ED discharge rate (24.3% to 50.2%, P < 0.001) and decrease the length of hospital stay (21.4 to 8.2 h, P < 0.001), radiation dose (10.2 to 7.7 mSv, P < 0.001), and costs of care (4066 to 3342 US$, P < 0.001).

CONCLUSIONS

We derived and validated a criterion for combined hs-cTnI and cardiovascular risk factors that identified acute chest pain patients with no need for cardiac testing and could improve effectiveness of patient management. ClinicalTrials.gov Identifiers: NCT00990262 and NCT01084239.

Age- and sex-based resource utilisation and costs in patients with acute chest pain undergoing cardiac CT angiography: pooled evidence from ROMICAT II and ACRIN-PA trials

OBJECTIVES

To determine resource utilisation according to age and gender-specific subgroups in two large randomized diagnostic trials.

METHODS

We pooled patient-specific data from ACRIN-PA 4005 and ROMICAT II that enrolled subjects with acute chest pain at 14 US sites. Subjects were randomized between a standard work-up and a pathway utilizing cardiac computed tomography angiography (CCTA) and followed for the occurrence of acute coronary syndrome (ACS) and resource utilisation during index hospitalisation and 1-month follow-up. Study endpoints included diagnostic accuracy of CCTA for the detection of ACS as well as resource utilisation.

RESULTS

Among 1240 patients who underwent CCTA, negative predictive value of CCTA to rule out ACS remained very high (≥99.4%). The proportion of patients undergoing additional diagnostic testing and cost increased with age for both sexes (p < 0.001), and was higher in men as compared to women older than 60 years (43.1% vs. 23.4% and $4559 ± 3382 vs. $3179 ± 2562, p < 0.01; respectively). Cost to rule out ACS was higher in men (p < 0.001) and significantly higher for patients older than 60 years ($2860-5935 in men, p < 0.001).

CONCLUSIONS

CCTA strategy in patients with acute chest pain results in varying resource utilisation according to age and gender-specific subgroups, mandating improved selection for advanced imaging.

KEY POINTS

• In this analysis, CAD and ACS increased with age and male gender. • CCTA in patients with acute chest pain results in varying resource utilisation. • Significant increase of diagnostic testing and cost with age for both sexes. • Cost to rule out ACS is higher in men and patients >60 years. • Improved selection of subjects for cardiac CTA result in more resource-driven implementation.

Clinical implementation of an emergency department coronary computed tomographic angiography protocol for triage of patients with suspected acute coronary syndrome

OBJECTIVES

To evaluate the efficiency and safety of emergency department (ED) coronary computed tomography angiography (CTA) during a 3-year clinical experience.

METHODS

Single-center registry of coronary CTA in consecutive ED patients with suspicion of acute coronary syndrome (ACS). The primary outcome was efficiency of coronary CTA defined as the length of hospitalization. Secondary endpoints of safety were defined as the rate of downstream testing, normalcy rates of invasive coronary angiography (ICA), absence of missed ACS, and major adverse cardiac events (MACE) during follow-up, and index radiation exposure.

RESULTS

One thousand twenty two consecutive patients were referred for clinical coronary CTA with suspicion of ACS. Overall, median time to discharge home was 10.5 (5.7-24.1) hours. Patient disposition was 42.7 % direct discharge from the ED, 43.2 % discharge from emergency unit, and 14.1 % hospital admission. ACS rate during index hospitalization was 9.1 %. One hundred ninety two patients underwent additional diagnostic imaging and 77 underwent ICA. The positive predictive value of CTA compared to ICA was 78.9 % (95 %-CI 68.1-87.5 %). Median CT radiation exposure was 4.0 (2.5-5.8) mSv. No ACS was missed; MACE at follow-up after negative CTA was 0.2 %.

CONCLUSIONS

Coronary CTA in an experienced tertiary care setting allows for efficient and safe management of patients with suspicion for ACS.

KEY POINTS

• ED Coronary CTA using advanced systems is associated with low radiation exposure. • Negative coronary CTA is associated with low rates of MACE. • CTA in ED patients enables short median time to discharge home. • CTA strategy is characterized by few downstream tests including unnecessary ICA.

Impact of Coronary Calcification on Clinical Management in Patients With Acute Chest Pain

BACKGROUND

Coronary artery calcification (CAC) may impair diagnostic assessment of coronary computed tomography angiography (CTA). We determined whether CAC affects efficiency of coronary CTA in patients with suspected acute coronary syndrome (ACS).

METHODS AND RESULTS

This is a pooled analysis of ACRIN-PA (American College of Radiology Imaging Network-Pennsylvania) 4005 and the ROMICAT-II trial (Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography) comparing an initial coronary CTA strategy to standard of care in acute chest pain patients. In the CTA arms, we investigated appropriateness of downstream testing, cost, and diagnostic yield to identify patients with obstructive coronary artery disease on subsequent invasive coronary angiography across CAC score strata (Agatston score: 0, >0-10, >10-100, >100-400, >400). Out of 1234 patients (mean age 51±8.8 years), 80 (6.5%) had obstructive coronary artery disease (≥70% stenosis) and 68 (5.5%) had ACS. Prevalence of obstructive coronary artery disease (1%-64%), ACS (1%-44%), downstream testing (4%-72%), and total (2337-8484 US$) and diagnostic cost (2310-6678 US$) increased across CAC strata (P<0.001). As the increase in testing and cost were lower than the increase of ACS rate in patients with CAC>400, cost to diagnose one ACS was lowest in this group (19 283 US$ versus 464 399 US$) as compared with patients without CAC. The diagnostic yield of invasive coronary angiography was highest in patients with CAC>400 (87% versus 38%).

CONCLUSIONS

Downstream testing, total, and diagnostic cost increased with increasing CAC, but were found to be appropriate because obstructive coronary artery disease and ACS were more prevalent in patients with high CAC. In patients with acute chest pain undergoing coronary CTA, cost-efficient testing and excellent diagnostic yield can be achieved even with high CAC burden.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifiers: NCT01084239 and NCT00933400.

Necessity of hospitalization and stress testing in low risk chest pain patients

BACKGROUND

Copeptin is a marker of endogenous stress including early myocardial infarction(MI) and has value in early rule out of MI when used with cardiac troponin I(cTnI).

OBJECTIVES

The goal of this study was to demonstrate that patients with a normal electrocardiogram and cTnI<0.040μg/l and copeptin<14pmol/l at presentation and after 2 h may be candidates for early discharge with outpatient follow-up potentially including stress testing.

METHODS

This study uses data from the CHOPIN trial which enrolled 2071 patients with acute chest pain. Of those, 475 patients with normal electrocardiogram and normal cTnI(<0.040μg/l) and copeptin<14pmol/l at presentation and after 2 h were considered "low risk" and selected for further analysis.

RESULTS

None of the 475 "low risk" patients were diagnosed with MI during the 180day follow-up period (including presentation). The negative predictive value of this strategy was 100% (95% confidence interval(CI):99.2%-100.0%). Furthermore no one died during follow up. 287 (60.4%) patients in the low risk group were hospitalized. In the "low risk" group, the only difference in outcomes (MI, death, revascularization, cardiac rehospitalization) was those hospitalized underwent revascularization more often (6.3%[95%CI:3.8%-9.7%] versus 0.5%[95%CI:0.0%-2.9%], p=.002). The hospitalized patients were tested significantly more via stress testing or angiogram (68.6%[95%CI:62.9%-74.0%] vs 22.9%[95%CI:17.1%-29.6%], p<.001). Those tested had less cardiac rehospitalizations during follow-up (1.7% vs 5.1%, p=.040).

CONCLUSIONS

In conclusion, patients with a normal electrocardiogram, troponin and copeptin at presentation and after 2 h are at low risk for MI and death over 180days. These low risk patients may be candidates for early outpatient testing and cardiology follow-up thereby reducing hospitalization.

Pilot Study of Neurological Soft Signs and Depressive and Postconcussive Symptoms During Recovery From Mild Traumatic Brain Injury (mTBI)

Neurological soft signs (NSSs) tap into a variety of perceptual, motor, and cognitive functions. The authors administered a battery of NSSs serially to a group of 14 pilot patients recruited from an emergency room after they experienced a mild traumatic brain injury. Patients were seen within 96 hours after injury, and again 30 and 90 days later. Measures of balance, mood, and postconcussive symptoms and impairment were also obtained. NSSs and balance improved across visits. Across visits, NSSs and balance were not significantly associated with any postconcussive outcome measures, although depressive symptoms were. Initial neurological impairment appeared to predict subsequent residual postconcussive symptoms and impairment, but this result requires replication.

Coronary CT Angiography Versus Standard Emergency Department Evaluation for Acute Chest Pain and Diabetic Patients: Is There Benefit With Early Coronary CT Angiography? Results of the Randomized Comparative Effectiveness ROMICAT II Trial

Background

Cardiac computed tomography angiography (CCTA) reduces emergency department length of stay compared with standard evaluation in patients with low‐ and intermediate‐risk acute chest pain. Whether diabetic patients have similar benefits is unknown.

Methods and Results

In this prespecified analysis of the Rule Out Myocardial Ischemia/Infarction by Computer Assisted Tomography (ROMICAT II) multicenter trial, we randomized 1000 patients (17% diabetic) with symptoms suggestive of acute coronary syndrome to CCTA or standard evaluation. The rate of acute coronary syndrome was 8% in both diabetic and nondiabetic patients (P=1.0). Length of stay was unaffected by the CCTA strategy for diabetic patients (23.9 versus 27.2 hours, P=0.86) but was reduced for nondiabetic patients compared with standard evaluation (8.4 versus 26.5 hours, P<0.0001; P interaction=0.004). CCTA resulted in 3‐fold more direct emergency department discharge in both groups (each P≤0.0001, P interaction=0.27). No difference in hospital admissions was seen between the 2 strategies in diabetic and nondiabetic patients (P interaction=0.09). Both groups had more downstream testing and higher radiation doses with CCTA, but these were highest in diabetic patients (all P interaction≤0.04). Diabetic patients had fewer normal CCTAs than nondiabetic patients (32% versus 50%, P=0.003) and similar normalcy rates with standard evaluation (P=0.70). Notably, 66% of diabetic patients had no or mild stenosis by CCTA with short length of stay comparable to that of nondiabetic patients (P=0.34), whereas those with >50% stenosis had a high prevalence of acute coronary syndrome, invasive coronary angiography, and revascularization.

Conclusions

Knowledge of coronary anatomy with CCTA is beneficial for diabetic patients and can discriminate between lower risk patients with no or little coronary artery disease who can be discharged immediately and higher risk patients with moderate to severe disease who warrant further workup.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov/. Unique identifier: NCT01084239.

Comparison between admission natriuretic peptides, NGAL and sST2 testing for the prediction of worsening renal function in patients with acutely decompensated heart failure

BACKGROUND

In order to predict the occurrence of worsening renal function (WRF) and of WRF plus in-hospital death, 101 emergency department (ED) patients with acute decompensated heart failure (ADHF) were evaluated with testing for amino-terminal pro-B-type natriuretic peptide (NT-proBNP), BNP, sST2, and neutrophil gelatinase associated lipocalin (NGAL).

METHODS

In a prospective international study, biomarkers were collected at the time of admission; the occurrence of subsequent in hospital WRF was evaluated.

RESULTS

In total 26% of patients developed WRF. Compared to patients without WRF, those with WRF had a longer in-hospital length of stay (LOS) (mean LOS 13.1±13.4 days vs. 4.8±3.7 days, p<0.001) and higher in-hospital mortality [6/26 (23%) vs. 2/75 (2.6%), p<0.001]. Among the biomarkers assessed, baseline NT-proBNP (4846 vs. 3024 pg/mL; p=0.04), BNP (609 vs. 435 pg/mL; p=0.05) and NGAL (234 vs. 174 pg/mL; p=0.05) were each higher in those who developed WRF. In logistic regression, the combination of elevated natriuretic peptide and NGAL were additively predictive for WRF (ORNT-proBNP+NGAL=2.79; ORBNP+NGAL=3.11; both p<0.04). Rates of WRF were considerably higher in patients with elevation of both classes of biomarker. Comparable results were observed in a separate cohort of 162 patients with ADHF from a different center.

CONCLUSIONS

In ED patients with ADHF, the combination of NT-proBNP or BNP plus NGAL at presentation may be useful to predict impending WRF (Clinicaltrials.gov NCT#0150153).

hs-Troponin I Followed by CT Angiography Improves Acute Coronary Syndrome Risk Stratification Accuracy and Work-Up in Acute Chest Pain Patients: Results From ROMICAT II Trial

OBJECTIVES

This study compared diagnostic accuracy of conventional troponin/traditional coronary artery disease (CAD) assessment and highly sensitive troponin (hsTn) I/advanced CAD assessment for acute coronary syndrome (ACS) during the index hospitalization.

BACKGROUND

hsTnI and advanced assessment of CAD using coronary computed tomography angiography (CTA) are promising candidates to improve the accuracy of emergency department evaluation of patients with suspected ACS.

METHODS

We performed an observational cohort study in patients with suspected ACS enrolled in the ROMICAT II (Rule Out Myocardial Infarction/Ischemia using Computer Assisted Tomography) trial and randomized to coronary CTA who also had hsTnI measurement at the time of the emergency department presentation. We assessed coronary CTA for traditional (no CAD, nonobstructive CAD, ≥50% stenosis) and advanced features of CAD (≥50% stenosis, high-risk plaque features: positive remodeling, low <30-Hounsfield units plaque, napkin-ring sign, spotty calcium).

RESULTS

Of 160 patients (mean age: 53 ± 8 years, 40% women) 10.6% were diagnosed with ACS. The ACS rate in patients with hsTnI below the limit of detection (n = 9, 5.6%), intermediate (n = 139, 86.9%), and above the 99th percentile (n = 12, 7.5%) was 0%, 8.6%, and 58.3%, respectively. Absence of ≥50% stenosis and high-risk plaque ruled out ACS in patients with intermediate hsTnI (n = 87, 54.4%; ACS rate 0%), whereas patients with both ≥50% stenosis and high-risk plaque were at high risk (n = 13, 8.1%; ACS rate 69.2%) and patients with either ≥50% stenosis or high-risk plaque were at intermediate risk for ACS (n = 39, 24.4%; ACS rate 7.7%). hsTnI/advanced coronary CTA assessment significantly improved the diagnostic accuracy for ACS as compared to conventional troponin/traditional coronary CTA (area under the curve 0.84, 95% confidence interval [CI]: 0.80 to .88 vs. 0.74, 95% CI: 0.70 to 0.78; p < 0.001).

CONCLUSIONS

hsTnI at the time of presentation followed by early advanced coronary CTA assessment improves the risk stratification and diagnostic accuracy for ACS as compared to conventional troponin and traditional coronary CTA assessment. (Multicenter Study to Rule Out Myocardial Infarction/Ischemia by Cardiac Computed Tomography [ROMICAT-II]; NCT01084239).

Use of coronary artery calcium scanning beyond coronary computed tomographic angiography in the emergency department evaluation for acute chest pain: the ROMICAT II trial

BACKGROUND

Whether a coronary artery calcium (CAC) scan provides added value to coronary computed tomographic angiography (CCTA) in emergency department patients with acute chest pain remains unsettled. We sought to determine the value of CAC scan in patients with acute chest pain undergoing CCTA.

METHODS AND RESULTS

In the multicenter Rule Out Myocardial Infarction using Computer-Assisted Tomography (ROMICAT) II trial, we enrolled low-intermediate risk emergency department patients with symptoms suggesting acute coronary syndrome (ACS). In this prespecified subanalysis of 473 patients (54±8 years, 53% men) who underwent both CAC scanning and CCTA, the ACS rate was 8%. Overall, 53% of patients had CAC=0 of whom 2 (0.8%) developed ACS, whereas 7% had CAC>400 with 49% whom developed ACS. C-statistic of CAC>0 was 0.76, whereas that using the optimal cut point of CAC≥22 was 0.81. Continuous CAC score had lower discriminatory capacity than CCTA (c-statistic, 0.86 versus 0.92; P=0.03). Compared with CCTA alone, there was no benefit combining CAC score with CCTA (c-statistic, 0.93; P=0.88) or with selective CCTA strategies after initial CAC>0 or optimal cut point CAC≥22 (P≥0.09). Mean radiation dose from CAC acquisition was 1.4±0.7 mSv. Higher CAC scores resulted in more nondiagnostic CCTA studies although the majority remained interpretable.

CONCLUSIONS

In emergency department patients with acute chest pain, CAC score does not provide incremental value beyond CCTA for ACS diagnosis. CAC=0 does not exclude ACS, nor a high CAC score preclude interpretation of CCTA in most patients. Thus, CAC results should not influence the decision to proceed with CCTA, and the decision to perform a CAC scan should be balanced with the additional radiation exposure required.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT01084239.

Potential for coronary CT angiography to tailor medical therapy beyond preventive guideline-based recommendations: insights from the ROMICAT I trial

BACKGROUND

Coronary CT angiography (CCTA) is used in the emergency department to rule out acute coronary syndrome in low-intermediate risk patients.

OBJECTIVES

We evaluated the potential of CCTA to tailor aspirin (ASA) and statin therapy in acute chest pain patients.

METHODS

We included all patients in the ROMICAT I trial who underwent CCTA before admission. Results of CCTA were blinded to caretakers. We documented ASA and statin therapy at admission and discharge and determined change in medications during hospitalization, agreement of discharge medications with contemporaneous guidelines, and agreement with the presence and severity of coronary artery disease (CAD) as determined by CCTA.

RESULTS

We included 368 patients (53 ± 12 years; 61% male). Baseline medical therapy at presentation included 27% on ASA and 24% on statin. Most patients who qualified for secondary prevention were on ASA and statin therapy at discharge (95% and 80%, respectively), whereas among those qualifying for primary prevention therapy, only 59% of patients were on aspirin and 33% were on statin at discharge. Excluding secondary prevention patients, among those with CCTA-detected CAD, only 66/131 (50%) were on ASA at discharge and only 53/131 (40%) were on statin. Conversely, in those without CCTA-detected CAD, 54/156 (35%) were on ASA and 20/151 (13%) were on statin at discharge.

CONCLUSION

There are significant discrepancies between discharge prescription of statin and ASA with the presence and extent of CAD. CCTA presents an efficient opportunity to tailor medical therapy to CAD in patients undergoing CCTA as part of their acute chest pain evaluation.

Gender-specific research for emergency diagnosis and management of ischemic heart disease: proceedings from the 2014 Academic Emergency Medicine Consensus Conference Cardiovascular Research Workgroup

Coronary artery disease (CAD) is the most common cause of death for both men and women. However, over the years, emergency physicians, cardiologists, and other health care practitioners have observed varying outcomes in men and women with symptomatic CAD. Women in general are 10 to 15 years older than men when they develop CAD, but suffer worse postinfarction outcomes compared to age-matched men. This article was developed by the cardiovascular workgroup at the 2014 Academic Emergency Medicine (AEM) consensus conference to identify sex- and gender-specific gaps in the key themes and research questions related to emergency cardiac ischemia care. The workgroup had diverse stakeholder representation from emergency medicine, cardiology, critical care, nursing, emergency medical services, patients, and major policy-makers in government, academia, and patient care. We implemented the nominal group technique to identify and prioritize themes and research questions using electronic mail, monthly conference calls, in-person meetings, and Web-based surveys between June 2013 and May 2014. Through three rounds of nomination and refinement, followed by an in-person meeting on May 13, 2014, we achieved consensus on five priority themes and 30 research questions. The overarching themes were as follows: 1) the full spectrum of sex-specific risk as well as presentation of cardiac ischemia may not be captured by our standard definition of CAD and needs to incorporate other forms of ischemic heart disease (IHD); 2) diagnosis is further challenged by sex/gender differences in presentation and variable sensitivity of cardiac biomarkers, imaging, and risk scores; 3) sex-specific pathophysiology of cardiac ischemia extends beyond conventional obstructive CAD to include other causes such as microvascular dysfunction, takotsubo, and coronary artery dissection, better recognized as IHD; 4) treatment and prognosis are influenced by sex-specific variations in biology, as well as patient-provider communication; and 5) the changing definitions of pathophysiology call for looking beyond conventionally defined cardiovascular outcomes to patient-centered outcomes. These emergency care priorities should guide future clinical and basic science research and extramural funding in an area that greatly influences patient outcomes.

High-risk plaque detected on coronary CT angiography predicts acute coronary syndromes independent of significant stenosis in acute chest pain: results from the ROMICAT-II trial

BACKGROUND

It is not known whether high-risk plaque, as detected by coronary computed tomography angiography (CTA), permits improved early diagnosis of acute coronary syndromes (ACS) independently to the presence of significant coronary artery disease (CAD) in patients with acute chest pain.

OBJECTIVES

The primary aim of this study was to determine whether high-risk plaque features, as detected by CTA in the emergency department (ED), may improve diagnostic certainty of ACS independently and incrementally to the presence of significant CAD and clinical risk assessment in patients with acute chest pain but without objective evidence of myocardial ischemia or myocardial infarction (MI).

METHODS

We included patients randomized to the coronary CTA arm of the ROMICAT-II (Rule Out Myocardial Infarction/Ischemia Using Computer-Assisted Tomography II) trial. Readers assessed coronary CTA qualitatively for the presence of nonobstructive CAD (1% to 49% stenosis), significant CAD (≥50% or ≥70% stenosis), and the presence of at least 1 of the high-risk plaque features (positive remodeling, low <30 Hounsfield units plaque, napkin-ring sign, spotty calcium). In logistic regression analysis, we determined the association of high-risk plaque with ACS (MI or unstable angina pectoris) during the index hospitalization and whether this was independent of significant CAD and clinical risk assessment.

RESULTS

Overall, 37 of 472 patients who underwent coronary CTA with diagnostic image quality (mean age 53.9 ± 8.0 years; 52.8% men) had ACS (7.8%; MI n = 5; unstable angina pectoris n = 32). CAD was present in 262 patients (55.5%; nonobstructive CAD in 217 patients [46.0%] and significant CAD with ≥50% stenosis in 45 patients [9.5%]). High-risk plaques were more frequent in patients with ACS and remained a significant predictor of ACS (odds ratio [OR]: 8.9; 95% CI: 1.8 to 43.3; p = 0.006) after adjustment for ≥50% stenosis (OR: 38.6; 95% CI: 14.2 to 104.7; p < 0.001) and clinical risk assessment (age, sex, number of cardiovascular risk factors). Similar results were observed after adjustment for ≥70% stenosis.

CONCLUSIONS

In patients presenting to the ED with acute chest pain but negative initial electrocardiogram and troponin, presence of high-risk plaques on coronary CTA increased the likelihood of ACS independent of significant CAD and clinical risk assessment (age, sex, and number of cardiovascular risk factors). (Multicenter Study to Rule Out Myocardial Infarction by Cardiac Computed Tomography [ROMICAT-II]; NCT01084239).

Cost and resource utilization associated with use of computed tomography to evaluate chest pain in the emergency department: the Rule Out Myocardial Infarction using Computer Assisted Tomography (ROMICAT) study

BACKGROUND

Coronary computed tomographic angiography (cCTA) allows rapid, noninvasive exclusion of obstructive coronary artery disease (CAD). However, concern exists whether implementation of cCTA in the assessment of patients presenting to the emergency department with acute chest pain will lead to increased downstream testing and costs compared with alternative strategies. Our aim was to compare observed actual costs of usual care (UC) with projected costs of a strategy including early cCTA in the evaluation of patients with acute chest pain in the Rule Out Myocardial Infarction Using Computer Assisted Tomography I (ROMICAT I) study.

METHODS AND RESULTS

We compared cost and hospital length of stay of UC observed among 368 patients enrolled in the ROMICAT I study with projected costs of management based on cCTA. Costs of UC were determined by an electronic cost accounting system. Notably, UC was not influenced by cCTA results because patients and caregivers were blinded to the cCTA results. Costs after early implementation of cCTA were estimated assuming changes in management based on cCTA findings of the presence and severity of CAD. Sensitivity analysis was used to test the influence of key variables on both outcomes and costs. We determined that in comparison with UC, cCTA-guided triage, whereby patients with no CAD are discharged, could reduce total hospital costs by 23% (P<0.001). However, when the prevalence of obstructive CAD increases, index hospitalization cost increases such that when the prevalence of ≥ 50% stenosis is >28% to 33%, the use of cCTA becomes more costly than UC.

CONCLUSIONS

cCTA may be a cost-saving tool in acute chest pain populations that have a prevalence of potentially obstructive CAD <30%. However, increased cost would be anticipated in populations with higher prevalence of disease.

Frequent ED users: are most visits for mental health, alcohol, and drug-related complaints?

STUDY OBJECTIVE

To determine whether frequent emergency department (ED) users are more likely to make at least one and a majority of visits for mental health, alcohol, or drug-related complaints compared to non-frequent users.

METHODS

We performed a retrospective cohort study exploring frequent ED use and ED diagnosis at a single, academic hospital and included all ED patients between January 1 and December 31, 2010. We compared differences in ED visits with a primary International Classification of Diseases, 9th Revision visit diagnosis of mental health, alcohol or drug-related diagnoses between non-frequent users (<4 visits during previous 12-months) and frequent (repeat [4-7 visits], highly frequent [8-18 visits] and super frequent [≥19 visits]) users in univariate and multivariable analyses.

RESULTS

Frequent users (2496/65201 [3.8%] patients) were more likely to make at least one visit associated with mental health, alcohol, or drug-related diagnoses. The proportion of patients with a majority of visits related to any of the three diagnoses increased from 5.8% among non-frequent users (3616/62705) to 9.4% among repeat users (181/1926), 13.1% among highly frequent users (62/473), and 25.8% (25/97 patients) in super frequent users. An increasing proportion of visits with alcohol-related diagnoses was observed among repeat, highly frequent, and super frequent users but was not found for mental health or drug-related complaints.

CONCLUSION

Frequent ED users were more likely to make a mental health, alcohol or drug-related visit, but a majority of visits were only noted for those with alcohol-related diagnoses. To address frequent ED use, interventions focusing on managing patients with frequent alcohol-related visits may be necessary.

Single resting hsTnT level predicts abnormal myocardial stress test in acute chest pain patients with normal initial standard troponin

OBJECTIVES

The goal of this study was to determine the ability of a single, resting high-sensitivity troponin T (hsTnT) measurement to predict abnormal myocardial perfusion imaging (MPI) in patients presenting with acute chest pain to the emergency department (ED).

BACKGROUND

HsTnT assays precisely detect very low levels of troponin T, which may be a surrogate for the presence and extent of myocardial ischemia.

METHODS

We included all patients from the ROMICAT I (Rule Out Myocardial Infarction Using Computer Assisted Tomography) trial, an observational cohort study, who underwent both single-photon emission computed tomography (SPECT)-MPI stress testing and 64-slice computed tomography angiography (CTA) and in whom hsTnT measurements were available. We assessed the discriminatory value of hsTnT for abnormal SPECT-MPI and the association of reversible myocardial ischemia by SPECT-MPI and the extent of coronary atherosclerosis by CTA to hsTnT levels.

RESULTS

Of the 138 patients (mean age 54 ± 11 years, 46% male), 19 (13.7%) had abnormal SPECT-MPI. Median hsTnT levels were significantly different between patients with normal and abnormal SPECT-MPI (9.41 pg/ml [interquartile range (IQR): 5.73 to 19.20 pg/ml] vs. 4.89 pg/ml [IQR: 2.34 to 7.68 pg/ml], p = 0.001). Sensitivity of 80% and 90% to detect abnormal SPECT-MPI was reached at hsTnT levels as low as 5.73 and 4.26 pg/ml, respectively. Corresponding specificity was 62% and 46%, and negative predictive value was 96% and 96%, respectively. HsTnT levels had good discriminatory ability for prediction of abnormal SPECT-MPI (area under the curve: 0.739, 95% confidence interval: 0.609 to 0.868). Both reversible myocardial ischemia and the extent of coronary atherosclerosis (combined model r(2) = 0.19 with partial of r(2) = 0.12 and r(2) = 0.05, respectively) independently and incrementally predicted the measured hsTnT levels.

CONCLUSIONS

In patients with acute chest pain, myocardial perfusion abnormalities and coronary artery disease are predicted by resting hsTnT levels. Prospective evaluations are warranted to confirm whether resting hsTnT could serve as a powerful triage tool in chest pain patients in the ED before diagnostic testing and improve the effectiveness of patient management.

Evaluation of renal function tests by age and sex to determine emergency department patients' eligibility for cardiac computed tomography

BACKGROUND

Coronary computed tomography angiography (CCTA) can be used for low-risk chest pain patients, but presents a risk of contrast-induced nephropathy.

OBJECTIVE

We compared, by age and sex, the percent of patients who would become ineligible for CCTA based on serum creatinine (SCr) and glomerular filtration rate (GFR) cutoff points.

METHODS

All adult patients who presented to the Emergency Department (ED) with chest pain were screened using their first ED SCr as part of the ROMICAT (Rule Out Myocardial Infarction Using Computer Assisted Tomography) study. This was a secondary analysis of the screening logs of that study. The Modification of Diet in Renal Disease formula was applied to calculate estimated GFR and the percent of patients, by age and sex, meeting commonly applied exclusion criteria using selected SCr and GFR cutoff values. This was our primary outcome.

RESULTS

Of 2398 patients screened, 384 (16%) were excluded for high-risk features or technical limitations of CCTA, leaving 2014 patients who were studied; 56% were male. For all cutoff points of SCr (≥1.3 mg/dL, ≥1.5 mg/dL, ≥1.8 mg/dL), the percent of males excluded significantly exceeded that of females (p < 0.0001 [28.6% males to 18.5% females]; p < 0.0001 [17.4% males to 11.2% females]; p = 0.0004 [10.1% males to 5.8% females], respectively). Conversely, for two of the three cutoff points of GFR (≤60 mL/min/1.73 m(2) and ≤45 mL/min/1.73 m(2)), the percent of females excluded significantly exceeded that of males (p < 0.0001 [33.6% females to 25.4% males] and p = 0.0015 [17.6% males to 12.5% females], respectively).

CONCLUSIONS

The choice of SCr or GFR to screen patients for CCTA selectively excludes either males or females, respectively. Therefore, individual physicians and institutions must understand the impact of both renal function tests and cutoff points when identifying patients who may be eligible for CCTA.

Sex differences in the effectiveness of early coronary computed tomographic angiography compared with standard emergency department evaluation for acute chest pain: the rule-out myocardial infarction with Computer-Assisted Tomography (ROMICAT)-II Trial

BACKGROUND

We evaluate sex-based differences in the effectiveness of early cardiac computed tomographic angiography (CCTA) and standard emergency department (ED) evaluation in patients with acute chest pain.

METHODS AND RESULTS

In the Rule-Out Myocardial Infarction With Computer-Assisted Tomography (ROMICAT)-II multicenter, controlled trial, we randomized 1000 patients (47% women) 40 to 74 years of age with symptoms suggestive of acute coronary syndrome to an early CCTA or standard ED evaluation. In this prespecified analysis, women in the CCTA arm had a greater reduction in length of stay, lower hospital admission rates, and lesser increased cumulative radiation dose than men in a comparison of ED strategies (P for interaction ≤0.02). Although women had lower acute coronary syndrome rates than men (3% versus 12%; P<0.0001), sex differences in length of stay persisted after adjustment for baseline differences, including acute coronary syndrome rate (P for interaction <0.03). Length of stay was similar between sexes with normal CCTA findings (P=0.11). There was no missed acute coronary syndrome for either sex. No difference was observed in major adverse cardiac events between sexes and ED strategies (P for interaction =0.39). Women had more normal CCTA examinations than men (58% versus 37%; P<0.0001), less obstructive coronary disease by CCTA (5% versus 17%; P=0.0001), but similar normalcy rates for functional testing (P=0.65). Men in the CCTA arm had the highest rate of invasive coronary angiography (18%), whereas women had comparable low 5% rates regardless of ED strategy.

CONCLUSIONS

This trial provides data supporting an early CCTA strategy as an attractive option in women presenting to the ED with symptoms suggestive of acute coronary syndrome. The findings may be explained by lower CAD prevalence and severity in women than men.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT01084239.

Central versus local adjudication of myocardial infarction in a cardiac biomarker trial

OBJECTIVES

The impact of regulatory requirements, which require central adjudication for the diagnosis of acute myocardial infarction (AMI) in cardiac biomarker studies, is unclear. We determined the impact of local (at the site of subject enrollment) versus central adjudication of AMI on final diagnosis.

METHODS

This is a retrospective analysis of data from the Myeloperoxidase in the Diagnosis of Acute Coronary Syndromes Study, an 18-center prospective study of patients with suspected acute coronary syndromes, with enrollment from December 19, 2006, to September 20, 2007. Local adjudication of AMI was performed by a single site investigator at each center following the protocol-specified definition and according to the year 2000 definition of AMI, which based cardiac troponin (cTn) elevation on local cut points for each of the 13 different assays. After completion of the Myeloperoxidase in the Diagnosis of Acute Coronary Syndromes Study primary analysis and to evaluate a new troponin assay, a Food and Drug Administration-mandated central adjudication was performed by 3 investigators at different institutions. This adjudication used the 2007 Universal Definition of AMI, which differs by use of the manufacturer's 99th percentile cTn cut point. We describe the outcome of this process and compare it with the local adjudication. Central adjudicators were not blinded to local adjudications. For central adjudication, discrepant diagnoses were resolved by consensus. Local versus central cTn cut points differed for 6 assays. Both definitions required a rise and/or fall of cTn. Discrepant cases were reviewed by the lead author. Difficult cases were defined as having a difference between local and central adjudication, an elevated cTn with a temporal rise and fall, and a negative or absent risk stratification test. Statistics were by χ(2), κ, and logistic regression.

RESULTS

Of 1,107 patients enrolled, 11 had indeterminate central adjudication, leaving 1,096 for analysis. In spite of high agreement across central versus local adjudicators, κ = 0.79 (95% CI [0.73, 0.85]), AMI was diagnosed more often by central adjudication, 134 (12.2%) versus 104 (9.5%), with 44 local diagnoses (4%) changed from non-AMI to AMI (n = 37) or AMI to non-AMI (n = 7) (P < .001). These 44 represented 34% (95% CI 26%-42%) of 141 cases in which either central or local adjudication was AMI. Of diagnoses changed to AMI, 3 reasons contributed approximately one-third each: the local use of a non-99th percentile cTn cutoff (32%), the possibility of human error (34%), and difficult cases (34%).

CONCLUSION

Despite an acceptable κ, over a third of patients with a diagnosis of AMI were not assigned that diagnosis by both sets of adjudicators. This supports the importance of 1 standard method for diagnosis of AMI.

Incremental value of objective cardiac testing in addition to physician impression and serial contemporary troponin measurements in women

OBJECTIVES

Guidelines recommend that patients presenting to the emergency department (ED) with chest pain who are at low risk for acute coronary syndrome (ACS) receive an objective cardiac evaluation with a stress test or coronary imaging. It is uncertain whether all women derive benefit from this process. The study aim was to determine the incremental value of objective cardiac testing after serial cardiac markers and physician risk assessment.

METHODS

Women enrolled in the 18-site Myeloperoxidase in the Diagnosis of Acute Coronary Syndrome (MIDAS) study had serial troponin I measured at time 0 and 90 minutes and physician risk assessment for the presence of ACS. Risk estimates obtained at the time of ED evaluation were dichotomized as high or non-high risk. The primary outcome was the composite of acute myocardial infarction (AMI) or revascularization at 30 days. Logistic regression with receiver operator characteristic (ROC) curves and net reclassification index were used to determine the diagnostic accuracy for the composite outcome of 30-day MI or revascularization for two models: 1) troponin I results and physician risk assessment alone and 2) troponin I results, physician risk assessment, and objective cardiac testing.

RESULTS

A total of 460 women with a median age 58 years (interquartile range [IQR] = 48.5 to 68 years) were included, and 32 (6.9%) experienced AMI or revascularization by 30 days. Comparison of the area under the ROC curves (AUC) showed that the addition of objective cardiac testing to the combination of troponin I results and physician risk assessment did not significantly improve prediction of 30-day AMI or revascularization (AUC = 0.85 vs. 0.89; p = .053). Using a threshold of 1%, net reclassification index showed that the addition of objective cardiac testing to troponin I results and physician risk assessment worsened the prediction for 30-day AMI and revascularization. All of the reclassified patients were false positives, with nine (2.1%) patients incorrectly reclassified from <1% risk to ≥ 1% risk of 30-day AMI or revascularization.

CONCLUSIONS

In the era of contemporary troponin assays, objective cardiac testing after an ED clinician risk assessment of non-high risk and negative troponin I results at 0 and 90 minutes does not improve the prediction of 30-day AMI or revascularization in women presenting with chest pain or other symptoms of cardiac ischemia.

Emergency physician estimates of the probability of acute coronary syndrome in a cohort of patients enrolled in a study of coronary computed tomographic angiography

INTRODUCTION

Little information exists regarding how accurately emergency physicians (EPs) predict the probability of acute coronary syndrome (ACS). Our objective was to determine if EPs can accurately predict ACS in a prospectively identified cohort of emergency department (ED) patients who met enrolment criteria for a study of coronary computed tomographic angiography (CCTA) and were admitted for a "rule out ACS" protocol.

METHODS

A prospective observational pilot study in an academic medical centre was carried out. EPs caring for patients with chest pain provided whole-number estimates of the probability of ACS after clinical review. This substudy was part of the now published Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography (ROMICAT) study, a study of CCTA and admission of patients for a rule out ACS protocol after a nondiagnostic evaluation. Predictions were grouped into probability groups based on the validated Goldman criteria. ACS was determined by an adjudication committee using American Heart Association/American College of Cardiology/European Society of Cardiology guidelines.

RESULTS

A total of 334 predictions were obtained for a study population with a mean age of 54 (SD 12) years, 63% of whom were male. There were 35 ACS events. EPs predicted ACS better than by chance, and increasingly higher estimates were associated with a higher incidence of ACS (p = 0.0004). The percentage of patients with ACS was 0%, 6%, 7%, and 17%, respectively, for very low, low, intermediate, and high probability groups. EPs' estimates had a sensitivity of 63% using a > 20% probability of ACS to define a positive test. Lowering this threshold to > 7% to define a test as positive increased the sensitivity of physician estimates to 89% but lowered specificity from 65% to 24%.

CONCLUSION

Our data suggest that for a selected ED cohort meeting eligibility criteria for a study of CCTA, EPs predict ACS better than by chance, with an increasing proportion of patients proving to have ACS with increasing probability estimates. Lowering the estimate threshold does not result in an overall sensitivity level that is sufficient to send patients home from the ED and is associated with a poor specificity.

Identifying patients for early discharge: performance of decision rules among patients with acute chest pain

BACKGROUND

The HEART score and North American Chest Pain Rule (NACPR) are decision rules designed to identify acute chest pain patients for early discharge without stress testing or cardiac imaging. This study compares the clinical utility of these decision rules combined with serial troponin determinations.

METHODS AND RESULTS

A secondary analysis was conducted of 1005 participants in the Myeloperoxidase In the Diagnosis of Acute coronary syndromes Study (MIDAS). MIDAS is a prospective observational cohort of Emergency Department (ED) patients enrolled from 18 US sites with symptoms suggestive of acute coronary syndrome (ACS). The ability to identify participants for early discharge and the sensitivity for ACS at 30 days were compared among an unstructured assessment, NACPR, and HEART score, each combined with troponin measures at 0 and 3h. ACS, defined as cardiac death, acute myocardial infarction, or unstable angina, occurred in 22% of the cohort. The unstructured assessment identified 13.5% (95% CI 11.5-16%) of participants for early discharge with 98% (95% CI 95-99%) sensitivity for ACS. The NACPR identified 4.4% (95% CI 3-6%) for early discharge with 100% (95% CI 98-100%) sensitivity for ACS. The HEART score identified 20% (95% CI 18-23%) for early discharge with 99% (95% CI 97-100%) sensitivity for ACS. The HEART score had a net reclassification improvement of 10% (95% CI 8-12%) versus unstructured assessment and 19% (95% CI 17-21%) versus NACPR.

CONCLUSIONS

The HEART score with 0 and 3 hour serial troponin measures identifies a substantial number of patients for early discharge while maintaining high sensitivity for ACS.

Comparison of traditional cardiovascular risk models and coronary atherosclerotic plaque as detected by computed tomography for prediction of acute coronary syndrome in patients with acute chest pain

OBJECTIVES

The objective was to determine the association of four clinical risk scores and coronary plaque burden as detected by computed tomography (CT) with the outcome of acute coronary syndrome (ACS) in patients with acute chest pain. The hypothesis was that the combination of risk scores and plaque burden improved the discriminatory capacity for the diagnosis of ACS.

METHODS

The study was a subanalysis of the Rule Out Myocardial Infarction Using Computer-Assisted Tomography (ROMICAT) trial-a prospective observational cohort study. The authors enrolled patients presenting to the emergency department (ED) with a chief complaint of acute chest pain, inconclusive initial evaluation (negative biomarkers, nondiagnostic electrocardiogram [ECG]), and no history of coronary artery disease (CAD). Patients underwent contrast-enhanced 64-multidetector-row cardiac CT and received standard clinical care (serial ECG, cardiac biomarkers, and subsequent diagnostic testing, such as exercise treadmill testing, nuclear stress perfusion imaging, and/or invasive coronary angiography), as deemed clinically appropriate. The clinical providers were blinded to CT results. The chest pain score was calculated and the results were dichotomized to ≥10 (high-risk) and <10 (low-risk). Three risk scores were calculated, Goldman, Sanchis, and Thrombolysis in Myocardial Infarction (TIMI), and each patient was assigned to a low-, intermediate-, or high-risk category. Because of the low number of subjects in the high-risk group, the intermediate- and high-risk groups were combined into one. CT images were evaluated for the presence of plaque in 17 coronary segments. Plaque burden was stratified into none, intermediate, and high (zero, one to four, and more than four segments with plaque). An outcome panel of two physicians (blinded to CT findings) established the primary outcome of ACS (defined as either an acute myocardial infarction or unstable angina) during the index hospitalization (from the presentation to the ED to the discharge from the hospital). Logistic regression modeling was performed to examine the association of risk scores and coronary plaque burden to the outcome of ACS. Unadjusted models were individually fitted for the coronary plaque burden and for Goldman, Sanchis, TIMI, and chest pain scores. In adjusted analyses, the authors tested whether the association between risk scores and ACS persisted after controlling for the coronary plaque burden. The prognostic discriminatory capacity of the risk scores and plaque burden for ACS was assessed using c-statistics. The differences in area under the receiver-operating characteristic curve (AUC) and c-statistics were tested by performing the -2 log likelihood ratio test of nested models. A p value <0.05 was considered statistically significant.

RESULTS

Among 368 subjects, 31 (8%) subjects were diagnosed with ACS. Goldman (AUC = 0.61), Sanchis (AUC = 0.71), and TIMI (AUC = 0.63) had modest discriminatory capacity for the diagnosis of ACS. Plaque burden was the strongest predictor of ACS (AUC = 0.86; p < 0.05 for all comparisons with individual risk scores). The combination of plaque burden and risk scores improved prediction of ACS (plaque + Goldman AUC = 0.88, plaque + Sanchis AUC = 0.90, plaque + TIMI AUC = 0.88; p < 0.01 for all comparisons with coronary plaque burden alone).

CONCLUSIONS

Risk scores (Goldman, Sanchis, TIMI) have modest discriminatory capacity and coronary plaque burden has good discriminatory capacity for the diagnosis of ACS in patients with acute chest pain. The combined information of risk scores and plaque burden significantly improves the discriminatory capacity for the diagnosis of ACS.

Coronary CT angiography versus standard evaluation in acute chest pain

BACKGROUND

It is unclear whether an evaluation incorporating coronary computed tomographic angiography (CCTA) is more effective than standard evaluation in the emergency department in patients with symptoms suggestive of acute coronary syndromes.

METHODS

In this multicenter trial, we randomly assigned patients 40 to 74 years of age with symptoms suggestive of acute coronary syndromes but without ischemic electrocardiographic changes or an initial positive troponin test to early CCTA or to standard evaluation in the emergency department on weekdays during daylight hours between April 2010 and January 2012. The primary end point was length of stay in the hospital. Secondary end points included rates of discharge from the emergency department, major adverse cardiovascular events at 28 days, and cumulative costs. Safety end points were undetected acute coronary syndromes.

RESULTS

The rate of acute coronary syndromes among 1000 patients with a mean (±SD) age of 54±8 years (47% women) was 8%. After early CCTA, as compared with standard evaluation, the mean length of stay in the hospital was reduced by 7.6 hours (P<0.001) and more patients were discharged directly from the emergency department (47% vs. 12%, P<0.001). There were no undetected acute coronary syndromes and no significant differences in major adverse cardiovascular events at 28 days. After CCTA, there was more downstream testing and higher radiation exposure. The cumulative mean cost of care was similar in the CCTA group and the standard-evaluation group ($4,289 and $4,060, respectively; P=0.65).

CONCLUSIONS

In patients in the emergency department with symptoms suggestive of acute coronary syndromes, incorporating CCTA into a triage strategy improved the efficiency of clinical decision making, as compared with a standard evaluation in the emergency department, but it resulted in an increase in downstream testing and radiation exposure with no decrease in the overall costs of care. (Funded by the National Heart, Lung, and Blood Institute; ROMICAT-II ClinicalTrials.gov number, NCT01084239.).

A computed tomography-based coronary lesion score to predict acute coronary syndrome among patients with acute chest pain and significant coronary stenosis on coronary computed tomographic angiogram

We tested the hypothesis that morphologic lesion assessment helps detect acute coronary syndrome (ACS) during index hospitalization in patients with acute chest pain and significant stenosis on coronary computed tomographic angiogram (CTA). Patients who presented to an emergency department with chest pain but no objective signs of myocardial ischemia (nondiagnostic electrocardiogram and negative initial biomarkers) underwent CT angiography. CTA was analyzed for degree and length of stenosis, plaque area and volume, remodeling index, CT attenuation of plaque, and spotty calcium in all patients with significant stenosis (>50% in diameter) on CTA. ACS during index hospitalization was determined by a panel of 2 physicians blinded to results of CT angiography. For lesion characteristics associated with ACS, we determined cutpoints optimized for diagnostic accuracy and created lesion scores. For each score, we determined the odds ratio (OR) and discriminatory capacity for the prediction of ACS. Of the overall population of 368 patients, 34 had significant stenosis and 21 of those had ACS. Scores A (remodeling index plus spotty calcium: OR 3.5, 95% confidence interval [CI] 1.2 to 10.1, area under curve [AUC] 0.734), B (remodeling index plus spotty calcium plus stenosis length: OR 4.6, 95% CI 1.6 to 13.7, AUC 0.824), and C (remodeling index plus spotty calcium plus stenosis length plus plaque volume <90 HU: OR 3.4, 95% CI 1.5 to 7.9, AUC 0.833) were significantly associated with ACS. In conclusion, in patients presenting with acute chest pain and stenosis on coronary CTA, a CT-based score incorporating morphologic characteristics of coronary lesions had a good discriminatory value for detection of ACS during index hospitalization.

Multi-marker strategy of natriuretic peptide with either conventional or high-sensitivity troponin-T for acute coronary syndrome diagnosis in emergency department patients with chest pain: from the "Rule Out Myocardial Infarction using Computer Assisted Tomography" (ROMICAT) trial

BACKGROUND

Compared to troponin alone, a dual-marker strategy with natriuretic peptides may improve acute coronary syndrome (ACS) diagnosis with a single blood draw and provide physiologic information regarding underlying heart disease. We evaluate the value of adding natriuretic peptides (myocyte stress markers) to troponins (myocardial injury markers) for diagnosing ACS in emergency department patients with chest pain.

METHODS

In 328 patients (53 ± 12 years, 63% men) with an initially negative conventional troponin and nonischemic electrocardiogram who underwent 64-slice cardiac computed tomography (CT), we measured conventional troponin-T (cTnT), high-sensitivity troponin-T (hsTnT), N-terminal pro-B type natriuretic peptide, and mid-regional pro-atrial natriuretic peptide. ACS was defined as myocardial infarction or unstable angina. CT was evaluated for coronary plaque, stenosis, and regional wall motion abnormality.

RESULTS

Patients with ACS (n = 29, 9%) had higher concentrations of each biomarker compared to those without (all P < .01). Adding natriuretic peptides, especially N-terminal pro-B type natriuretic peptide, to both cTnT or hsTnT improved the C-statistics and net reclassification index for ACS, largely driven by correctly reclassifying events. Dual-negative marker results improved sensitivity (cTnT 38% to 83%-86%, hsTnT 59% to 86%-90%; all P < .01) and negative predictive value (cTnT 94% to 97%-98%, hsTnT 96% to 97%-98%) for ACS. Patients with dual-negative markers had the lowest percentage of CT coronary plaque, stenosis, and regional wall motion abnormality (all P-trend <.001).

CONCLUSION

Among emergency department patients with low-intermediate likelihood of ACS, combining natriuretic peptides with either conventional or highly-sensitive troponin improved discriminatory capacity and allowed for better reclassification of ACS, findings supported by structural and functional CT results.