EMS blood collection from patients with acute chest pain reduces emergency department length of stay

BACKGROUND

Expediting the measurement of serum troponin by leveraging EMS blood collection could reduce the diagnostic time for patients with acute chest pain and help address Emergency Department (ED) overcrowding. However, this practice has not been examined among an ED chest pain patient population in the United States.

METHODS

A prospective observational cohort study of adults with non-traumatic chest pain without ST-segment elevation myocardial infarction was conducted in three EMS agencies between 12/2016-4/2018. During transport, paramedics obtained a patient blood sample that was sent directly to the hospital core lab for troponin measurement. On ED arrival HEART Pathway assessments were completed by ED providers as part of standard care. ED providers were blinded to troponin results from EMS blood samples. To evaluate the potential impact on length of stay (LOS), the time difference between EMS blood draw and first clinical ED draw was calculated. To determine the safety of using troponin measures from EMS blood samples, the diagnostic performance of the HEART Pathway for 30-day major adverse cardiac events (MACE: composite of cardiac death, myocardial infarction (MI), coronary revascularization) was determined using EMS troponin plus arrival ED troponin and EMS troponin plus a serial 3-h ED troponin.

RESULTS

The use of EMS blood samples for troponin measures among 401 patients presenting with acute chest pain resulted in a mean potential reduction in LOS of 72.5 ± SD 35.7 min. MACE at 30 days occurred in 21.0% (84/401), with 1 cardiac death, 78 MIs, and 5 revascularizations without MI. Use of the HEART Pathway with EMS and ED arrival troponin measures yielded a NPV of 98.0% (95% CI: 89.6-100). NPV improved to 100% (95% CI: 92.9-100) when using the EMS and 3-h ED troponin measures.

CONCLUSIONS

EMS blood collection used for core lab ED troponin measures could significantly reduce ED LOS and appears safe when integrated into the HEART Pathway.

The disutility of stress testing in low-risk HEART Pathway patients

BACKGROUND

The HEART Pathway identifies low-risk chest pain patients for discharge from the Emergency Department without stress testing. However, HEART Pathway recommendations are not always followed. The objective of this study is to determine the frequency and diagnostic yield of stress testing among low-risk patients.

METHODS

An academic hospital's chest pain registry was analyzed for low-risk HEART Pathway patients (HEAR score ≤ 3 with non-elevated troponins) from 1/2017 to 7/2018. Stress tests were reviewed for inducible ischemia. Diagnostic yield was defined as the rate of obstructive CAD among patients with positive stress testing. T-test or Fisher's exact test was used to test the univariate association of age, sex, race/ethnicity, and HEAR score with stress testing. Multivariate logistic regression was used to determine the association of age, sex, race/ethnicity, and HEAR score with stress testing.

RESULTS

There were 4743 HEART Pathway assessments, with 43.7% (2074/4743) being low-risk. Stress testing was performed on 4.1% (84/2074). Of the 84 low-risk patients who underwent testing, 8.3% (7/84) had non-diagnostic studies and 2.6% (2/84) had positive studies. Among the 2 patients with positive studies, angiography revealed that 1 had widely patent coronary arteries and the other had multivessel obstructive coronary artery disease, making the diagnostic yield of stress testing 1.2% (1/84). Each one-point increase in HEAR score (aOR 2.17, 95% CI 1.45-3.24) and being male (aOR 1.59, 95% CI 1.02-2.49) were associated with testing.

CONCLUSIONS

Stress testing among low-risk HEART Pathway patients was uncommon, low yield, and more likely in males and those with a higher HEAR score.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

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

SUMMARY

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

CLINICALTRIALSGOV IDENTIFIER

NCT04488913.

A Model Research Curriculum for Emergency Medicine Residency: A Modified Delphi Consensus

BACKGROUND

Research training is important for all resident physicians to be able to interpret and critically appraise scientific literature. It is particularly important for those desiring future careers in academics or research. However, there is limited literature on research training in residency. The ideal scope and content of a model curriculum for research in emergency medicine (EM) residency programs has not been recently defined.

METHODS

We used a modified Delphi method to achieve expert consensus as to what content should be included in a model research curriculum for EM residents as well as for those who choose to undertake an elective in EM research.

RESULTS

Eight experts in EM clinical and education research participated in the modified Delphi process with two rounds of responses. Cronbach's alpha was 0.82 for round 1 and 0.95 for round 2. A curricular outline of 44 items was produced by this consensus process.

CONCLUSIONS

A model curriculum for EM research is proposed here, along with references to assist residencies in building curricular components.

Sex and race differences in safety and effectiveness of the HEART pathway accelerated diagnostic protocol for acute chest pain

BACKGROUND

The HEART Pathway is an accelerated diagnostic protocol for Emergency Department patients with possible acute coronary syndrome. The objective was to compare the safety and effectiveness of the HEART Pathway among women vs men and whites vs non-whites.

METHODS

A subgroup analysis of the HEART Pathway Implementation Study was conducted. Adults with chest pain were accrued from November 2013 to January 2016 from 3 Emergency Departments in North Carolina. The primary outcomes were death and myocardial infarction (MI) and hospitalization rates at 30 days. Logistic regression evaluated for interactions of accelerated diagnostic protocol implementation with sex or race and changes in outcomes within subgroups.

RESULTS

A total of 8,474 patients were accrued, of which 53.6% were female and 34.0% were non-white. The HEART Pathway identified 32.6% of females as low-risk vs 28.5% of males (P = 002) and 35.6% of non-whites as low-risk vs 28.0% of whites (P < .0001). Among low-risk patients, death or MI at 30 days occurred in 0.4% of females vs 0.5% of males (P = .70) and 0.5% of non-whites vs 0.3% of whites (P = .69). Hospitalization at 30 days was reduced by 6.6% in females (aOR: 0.74, 95% CI: 0.64-0.85), 5.1% in males (aOR: 0.87, 95% CI: 0.75-1.02), 8.6% in non-whites (aOR: 0.72, 95% CI: 0.60-0.86), and 4.5% in whites (aOR: 0.83, 95% CI: 0.73-0.94). Interactions were not significant.

CONCLUSION

Women and non-whites are more likely to be classified as low-risk by the HEART Pathway. HEART Pathway implementation is associated with decreased hospitalizations and a very low death and MI rate among low-risk patients regardless of sex or race.

Diagnostic Performance of High-Sensitivity Cardiac Troponin T Strategies and Clinical Variables in a Multisite US Cohort

BACKGROUND

European data support the use of low high-sensitivity troponin (hs-cTn) measurements or a 0/1-hour (0/1-h) algorithm for myocardial infarction to exclude major adverse cardiac events (MACEs) among patients in the emergency department with possible acute coronary syndrome. However, modest US data exist to validate these strategies. This study evaluated the diagnostic performance of an initial hs-cTnT measure below the limit of quantification (LOQ: 6 ng/L), a 0/1-h algorithm, and their combination with history, ECG, age, risk factors, and initial troponin (HEART) scores for excluding MACE in a multisite US cohort.

METHODS

A prospective cohort study was conducted at 8 US sites, enrolling adult patients in the emergency department with symptoms suggestive of acute coronary syndrome and without ST-elevation on ECG. Baseline and 1-hour blood samples were collected, and hs-cTnT (Roche; Basel, Switzerland) was measured. Treating providers blinded to hs-cTnT results prospectively calculated HEART scores. MACE (cardiac death, myocardial infarction, and coronary revascularization) at 30 days was adjudicated. The proportion of patients with initial hs-cTnT measures below the LOQ and risk according to a 0/1-h algorithm was determined. The negative predictive value (NPV) was calculated for both strategies when used alone or with a HEART score.

RESULTS

Among 1462 participants with initial hs-cTnT measures, 46.4% (678 of 1462) were women and 37.1% (542 of 1462) were Black with an age of 57.6±12.9 (mean±SD) years. MACEs at 30 days occurred in 14.4% (210 of 1462) of participants. Initial hs-cTnT measures below the LOQ occurred in 32.8% (479 of 1462), yielding an NPV of 98.3% (95% CI, 96.7-99.3) for 30-day MACEs. A low-risk HEART score with an initial hs-cTnT below the LOQ occurred in 20.1% (294 of 1462), yielding an NPV of 99.0% (95% CI, 97.0-99.8) for 30-day MACEs. A 0/1-h algorithm was complete in 1430 patients, ruling out 57.8% (826 of 1430) with an NPV of 97.2% (95% CI, 95.9-98.2) for 30-day MACEs. Adding a low HEART score to the 0/1-h algorithm ruled out 30.8% (441 of 1430) with an NPV of 98.4% (95% CI, 96.8-99.4) for 30-day MACEs.

CONCLUSIONS

In a prospective multisite US cohort, an initial hs-cTnT below the LOQ combined with a low-risk HEART score has a 99% NPV for 30-day MACEs. The 0/1-h hs-cTnT algorithm did not achieve an NPV >99% for 30-day MACEs when used alone or with a HEART score. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02984436.

Prehospital use of a modified HEART Pathway and point-of-care troponin to predict cardiovascular events

The HEART Pathway is a validated risk stratification protocol for Emergency Department patients with chest pain that has yet to be tested in the prehospital setting. This study seeks to test the performance of a prehospital modified HEART Pathway (PMHP). A prospective cohort study of adults with chest pain without ST-segment elevation myocardial infarction was conducted at three EMS agencies between 12/2016-1/2018. To complete a PMHP assessment, paramedics drew blood, measured point-of-care (POC) troponin (i-STAT; Abbott Point of Care) and calculated a HEAR score. Patients were stratified into three groups: high-risk based on an elevated troponin, low-risk based on a HEAR score <4 with a negative troponin, or moderate risk for a HEAR score ≥4 with a negative troponin. Sensitivity, specificity, negative and positive predictive values of the PMHP for detection of major adverse cardiac events (MACE: cardiac death, MI, or coronary revascularization) at 30-days were calculated. A total of 506 patients were accrued, with PMHP completed in 78.1% (395/506). MACE at 30-days occurred in 18.7% (74/395). Among these patients, 7.1% (28/395) were high risk yielding a specificity and PPV for 30-day MACE of 96.6% (95%CI: 94.0–98.3%) and 60.7% (95%CI: 40.6–78.6%) respectively. Low-risk assessments occurred in 31.4% (124/395), which were 90.5% (95%CI: 81.5–96.1%) sensitive for 30-day MACE with a NPV of 94.4% (95%CI: 88.7–97.7%). Moderate-risk assessments occurred in 61.5% (243/395), of which 20.6% had 30-day MACE. The PMHP is able to identify high-risk and low-risk groups with high specificity and negative predictive value for 30-day MACE.

Identification of very low-risk acute chest pain patients without troponin testing

BACKGROUND

The HEART Pathway combines a History ECG Age Risk factor (HEAR) score and serial troponins to risk stratify patients with acute chest pain. However, it is unclear whether patients with HEAR scores of <1 require troponin testing. The objective of this study is to measure the major adverse cardiac event (MACE) rate among patients with <1 HEAR scores and determine whether serial troponin testing is needed to achieve a miss rate <1%.

METHODS

A secondary analysis of the HEART Pathway Implementation Study was conducted. HEART Pathway risk assessments (HEAR scores and serial troponin testing at 0 and 3 hours) were completed by the providers on adult patients with chest pain from three US sites between November 2014 and January 2016. MACE (composite of death, myocardial infarction (MI) and coronary revascularisation) at 30 days was determined. The proportion of patients with HEAR scores of <1 diagnosed with MACE within 30 days was calculated. The impact of troponin testing on patients with HEAR scores of <1 was determined using Net Reclassification Improvement Index (NRI).

RESULTS

Providers completed HEAR assessments on 4979 patients and HEAR scores<1 occurred in 9.0% (447/4979) of patients. Among these patients, MACE at 30 days occurred in 0.9% (4/447; 95% CI 0.2% to 2.3%) with two deaths, two MIs and 0 revascularisations. The sensitivity and negative predictive value for MACE in the HEAR <1 was 97.8% (95%CI 94.5% to 99.4%) and 99.1% (95% CI 97.7% to 99.8%), respectively, and were not improved by troponin testing. Troponin testing in patients with HEAR <1 correctly reclassified two patients diagnosed with MACE, and was elevated among seven patients without MACE yielding an NRI of 0.9% (95%CI -0.7 to 2.4%).

CONCLUSION

These data suggest that patients with HEAR scores of 0 and 1 represent a very low-risk group that may not require troponin testing to achieve a missed MACE rate <1%. Trial registration number NCT02056964.

HEART Pathway Implementation Safely Reduces Hospitalizations at One Year in Patients With Acute Chest Pain

STUDY OBJECTIVE

We determine whether implementation of the HEART (History, ECG, Age, Risk Factors, Troponin) Pathway is safe and effective in emergency department (ED) patients with possible acute coronary syndrome through 1 year of follow-up.

METHODS

A preplanned analysis of 1-year follow-up data from a prospective pre-post study of 8,474 adult ED patients with possible acute coronary syndrome from 3 US sites was conducted. Patients included were aged 21 years or older, evaluated for possible acute coronary syndrome, and without ST-segment elevation myocardial infarction. Accrual occurred for 12 months before and after HEART Pathway implementation, from November 2013 to January 2016. The HEART Pathway was integrated into the electronic health record at each site as an interactive clinical decision support tool. After integration, ED providers prospectively used the HEART Pathway to identify patients with possible acute coronary syndrome as low risk (appropriate for early discharge without stress testing or angiography) or nonlow risk (appropriate for further inhospital evaluation). Safety (all-cause death and myocardial infarction) and effectiveness (hospitalization) at 1 year were determined from health records, insurance claims, and death index data.

RESULTS

Preimplementation and postimplementation cohorts included 3,713 and 4,761 patients, respectively. The HEART Pathway identified 30.7% of patients as low risk; 97.5% of them were free of death and myocardial infarction within 1 year. Hospitalization at 1 year was reduced by 7.0% in the postimplementation versus preimplementation cohort (62.1% versus 69.1%; adjusted odds ratio 0.70; 95% confidence interval 0.63 to 0.78). Rates of death or myocardial infarction at 1 year were similar (11.6% versus 12.4%; adjusted odds ratio 1.00; 95% confidence interval 0.87 to 1.16).

CONCLUSION

HEART Pathway implementation was associated with decreased hospitalizations and low adverse event rates among low-risk patients at 1-year follow-up.

Comparison of accelerated diagnostic pathways for acute chest pain risk stratification

BACKGROUND

The History Electrocardiogram Age Risk factor Troponin (HEART) Pathway and Emergency Department Assessment of Chest pain Score (EDACS) are validated accelerated diagnostic pathways designed to risk stratify patients presenting to the emergency department with chest pain. Data from large multisite prospective studies comparing these accelerated diagnostic pathways are limited.

METHODS

The HEART Pathway Implementation is a prospective three-site cohort study, which accrued adults with symptoms concerning for acute coronary syndrome. Physicians completed electronic health record HEART Pathway and EDACS risk assessments on participants. Major adverse cardiac events (death, myocardial infarction and coronary revascularisation) at 30 days were determined using electronic health record, insurance claims and death index data. Test characteristics for detection of major adverse cardiac events were calculated for both accelerated diagnostic pathways and McNemar's tests were used for comparisons.

RESULTS

5799 patients presenting to the emergency department were accrued, of which HEART Pathway and EDACS assessments were completed on 4399. Major adverse cardiac events at 30 days occurred in 449/4399 (10.2%). The HEART Pathway identified 38.4% (95% CI 37.0% to 39.9%) of patients as low-risk compared with 58.1% (95% CI 56.6% to 59.6%) identified as low-risk by EDACS (p<0.001). Major adverse cardiac events occurred in 0.4% (95% CI 0.2% to 0.9%) of patients classified as low-risk by the HEART Pathway compared with 1.0% (95% CI 0.7% to 1.5%) of patients identified as low-risk by EDACS (p<0.001). Thus, the HEART Pathway had a negative predictive value of 99.6% (95% CI 99.1% to 99.8%) for major adverse cardiac events compared with a negative predictive value of 99.0% (95% CI 98.5% to 99.3%) for EDACS.

CONCLUSIONS

EDACS identifies a larger proportion of patients as low-risk than the HEART Pathway, but has a higher missed major adverse cardiac events rate at 30 days. Physicians will need to consider their risk tolerance when deciding whether to adopt the HEART Pathway or EDACS accelerated diagnostic pathway.

TRIAL REGISTRATION NUMBER

NCT02056964.

Safely Identifying Emergency Department Patients With Acute Chest Pain for Early Discharge

BACKGROUND

The HEART Pathway (history, ECG, age, risk factors, and initial troponin) is an accelerated diagnostic protocol designed to identify low-risk emergency department patients with chest pain for early discharge without stress testing or angiography. The objective of this study was to determine whether implementation of the HEART Pathway is safe (30-day death and myocardial infarction rate <1% in low-risk patients) and effective (reduces 30-day hospitalizations) in emergency department patients with possible acute coronary syndrome.

METHODS

A prospective pre-post study was conducted at 3 US sites among 8474 adult emergency department patients with possible acute coronary syndrome. Patients included were ≥21 years old, investigated for possible acute coronary syndrome, and had no evidence of ST-segment-elevation myocardial infarction on ECG. Accrual occurred for 12 months before and after HEART Pathway implementation from November 2013 to January 2016. The HEART Pathway accelerated diagnostic protocol was integrated into the electronic health record at each site as an interactive clinical decision support tool. After accelerated diagnostic protocol integration, ED providers prospectively used the HEART Pathway to identify patients with possible acute coronary syndrome as low risk (appropriate for early discharge without stress testing or angiography) or non-low risk (appropriate for further in-hospital evaluation). The primary safety and effectiveness outcomes, death, and myocardial infarction (MI) and hospitalization rates at 30 days were determined from health records, insurance claims, and death index data.

RESULTS

Preimplementation and postimplementation cohorts included 3713 and 4761 patients, respectively. The HEART Pathway identified 30.7% as low risk; 0.4% of these patients experienced death or MI within 30 days. Hospitalization at 30 days was reduced by 6% in the postimplementation versus preimplementation cohort (55.6% versus 61.6%; adjusted odds ratio, 0.79; 95% CI, 0.71-0.87). During the index visit, more MIs were detected in the postimplementation cohort (6.6% versus 5.7%; adjusted odds ratio, 1.36; 95% CI, 1.12-1.65). Rates of death or MI during follow-up were similar (1.1% versus 1.3%; adjusted odds ratio, 0.88; 95% CI, 0.58-1.33).

CONCLUSIONS

HEART Pathway implementation was associated with decreased hospitalizations, increased identification of index visit MIs, and a very low death and MI rate among low-risk patients. These findings support use of the HEART Pathway to identify low-risk patients who can be safely discharged without stress testing or angiography.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov . Unique identifier: NCT02056964.

A Multidisciplinary Self-Directed Learning Module Improves Knowledge of a Quality Improvement Instrument: The HEART Pathway

We created and tested an educational intervention to support implementation of an institution wide QI project (the HEART Pathway) designed to improve care for patients with acute chest pain. Although online learning modules have been shown effective in imparting knowledge regarding QI projects, it is unknown whether these modules are effective across specialties and healthcare professions. Participants, including nurses, advanced practice clinicians, house staff and attending physicians (N = 486), were enrolled into an online, self-directed learning course exploring the key concepts of the HEART Pathway. The module was completed by 97% of enrollees (469/486) and 90% passed on the first attempt (422/469). Out of 469 learners, 323 completed the pretest, learning module and posttest in the correct order. Mean test scores across learners improved significantly from 74% to 89% from the pretest to the posttest. Following the intervention, the HEART Pathway was used for 88% of patients presenting to our institution with acute chest pain. Our data demonstrate that this online, self-directed learning module can improve knowledge of the HEART Pathway across specialties-paving the way for more efficient and informed care for acute chest pain patients.

ACES (Accelerated Chest Pain Evaluation With Stress Imaging) Protocols Eliminate Testing Disparities in Patients With Chest Pain

BACKGROUND

Patients from racial and ethnic minority groups presenting to the Emergency Department (ED) with chest pain experience lower odds of receiving stress testing compared with nonminorities. Studies have demonstrated that care pathways administered within the ED can reduce health disparities, but this has yet to be studied as a strategy to increase stress testing equity.

METHODS

A secondary analysis from 3 randomized clinical trials involving ED patients with acute chest pain was performed to determine whether a care pathway, ACES (Accelerated Chest pain Evaluation with Stress imaging), reduces the racial disparity in index visit cardiac testing between African American (AA) and White patients. Three hundred thirty-four participants with symptoms and findings indicating intermediate to high risk for acute coronary syndrome were enrolled in 3 clinical trials. Major exclusions were ST-segment elevation, initial troponin elevation, and hemodynamic instability. Participants were randomly assigned to receive usual inpatient care, or ACES. The ACES care pathway includes placement in observation for serial cardiac markers, with an expectation for stress imaging. The primary outcome was index visit objective cardiac testing, compared among AA and White participants.

RESULTS

AA participants represented 111/329 (34%) of the study population, 80/220 (36%) of the ACES group and 31/109 (28%) of the usual care group. In usual care, objective testing occurred less frequently among AA (22/31, 71%) than among White (69/78, 88%, P = 0.027) participants, primarily driven by cardiac catheterization (3% vs. 24%; P = 0.012). In ACES, testing rates did not differ by race [AA 78/80 (98%) vs. White 138/140 (99%); P = 0.623]. At 90 days, death, MI, and revascularization did not differ in either group between AA and White participants.

CONCLUSIONS

A care pathway with the expectation for stress imaging eliminates the racial disparity among AA and White participants with chest pain in the acquisition of index-visit cardiovascular testing.

Recommendations for Institutions Transitioning to High-Sensitivity Troponin Testing: JACC Scientific Expert Panel

High-sensitivity cardiac troponin (hs-cTn) I or T methods have been in use in certain regions for years but are now increasingly globally adopted, including in the United States. Accordingly, inevitable challenges are created for institutions transitioning from conventional cardiac troponin (cTn) assays. hs-cTn assays have higher analytic precision at lower concentrations, yielding greater clinical sensitivity for myocardial injury and allowing accurate recognition of small changes in troponin concentration (rise or fall) within a short time frame. Although much of the knowledge regarding troponin biology that was applicable with older troponin assays still holds true, considerable education regarding the differences between conventional cTn and hs-cTn is needed before medical systems convert to the newer methods. This includes a basic understanding of how hs-cTn testing differs from conventional cTn testing and how it is best deployed in different settings, such as the emergency department and inpatient services. This Expert Panel will review important concepts for institutional transition to hs-cTn methodology, providing recommendations useful for education before implementation.

The HEART Pathway Randomized Controlled Trial One-year Outcomes

OBJECTIVE

The objective was to determine the impact of the HEART Pathway on health care utilization and safety outcomes at 1 year in patients with acute chest pain.

METHODS

Adult emergency department (ED) patients with chest pain (N = 282) were randomized to the HEART Pathway or usual care. In the HEART Pathway arm, ED providers used the HEART score and troponin measures (0 and 3 hours) to risk stratify patients. Usual care was based on American College of Cardiology/American Heart Association guidelines. Major adverse cardiac events (MACE-cardiac death, myocardial infarction [MI], or coronary revascularization), objective testing (stress testing or coronary angiography), and cardiac hospitalizations and ED visits were assessed at 1 year. Randomization arm outcomes were compared using Fisher's exact tests.

RESULTS

A total of 282 patients were enrolled, with 141 randomized to each arm. MACE at 1 year occurred in 10.6% (30/282): 9.9% in the HEART Pathway arm (14/141; 10 MIs, four revascularizations without MI) versus 11.3% in usual care (16/141; one cardiac death, 13 MIs, two revascularizations without MI; p = 0.85). Among low-risk HEART Pathway patients, 0% (0/66) had MACE, with a negative predictive value (NPV) of 100% (95% confidence interval = 93%-100%). Objective testing through 1 year occurred in 63.1% (89/141) of HEART Pathway patients compared to 71.6% (101/141) in usual care (p = 0.16). Nonindex cardiac-related hospitalizations and ED visits occurred in 14.9% (21/141) and 21.3% (30/141) of patients in the HEART Pathway versus 10.6% (15/141) and 16.3% (23/141) in usual care (p = 0.37, p = 0.36).

CONCLUSIONS

The HEART Pathway had a 100% NPV for 1-year safety outcomes (MACE) without increasing downstream hospitalizations or ED visits. Reduction in 1-year objective testing was not significant.

Usefulness of Serial 12-Lead Electrocardiograms in Predicting 30-Day Outcomes in Patients With Undifferentiated Chest Pain (the ASAP CATH Study)

An initial electrocardiogram (ECG) and serial troponin measurements are both independently and incrementally predictive of acute coronary syndrome in patients presenting with undifferentiated chest pain in the Emergency Department (ED). However, it is unclear if serial (ECGs) add significant to the contemporary diagnostic evaluation of this patient group. The ASAP CATH study was a single center, prospective study that enrolled patients presenting to an ED with undifferentiated chest pain. In addition to standard clinical evaluation, serial ECGs were performed at 90-minute intervals to evaluate whether serial changes suggestive of ischemia developed (Q waves, ST elevation or depression, or T-wave inversion). Total 365 subjects were enrolled from March 2014 to May 2015. Serial ECG changes developed in 6.6% (n = 24 of 365), the most common being the development of T-wave inversion (66.7%, n = 16 of 24). The sensitivity and positive predictive value of serial ECG changes were poor (<30%), with a less areas under the curve (0.55) compared with serial troponins alone (0.83). The addition of serial ECG changes to Thrombolysis In Myocardial Infarction risk scoring showed a decrease in the net reclassification index for major adverse cardiovascular events (-0.04, p <0.1) and was not significant for the prediction of major adverse cardiovascular events and/or acute coronary syndrome in 30 days (-0.003, p = 0.94). In conclusion, routine serial ECG evaluation for patients presenting with undifferentiated chest pain in the ED may not significantly improved diagnostic prognosis beyond current standard evaluation modalities.

Monocyte Chemoattractant Protein-1 as a Predictor of Coronary Atherosclerosis in Patients Receiving Coronary Angiography

BACKGROUND

Animal studies suggest that monocyte chemoattractant protein-1 (MCP-1) is a promising biomarker for coronary artery atherosclerosis (CAA), but human studies have been inconclusive.

OBJECTIVE

To determine potential relationships between plasma MCP-1 and CAA in patients with acute chest pain.

METHODS

A secondary analysis of 150 patients enrolled in emergency department chest pain risk stratification clinical investigations was conducted. Participants with stored blood and known coronary phenotypes (determined by coronary angiography) were selected using stratified randomization such that 50 patients were included into 3 groups: (1) no angiographic evidence of CAA, (2) nonobstructive CAA, and (3) obstructive CAA (stenosis ≥ 70%). Plasma MCP-1 levels were determined by enzyme-linked immunosorbent assay. The association between MCP-1 and obstructive CAA or any CAA was modeled using logistic regression. Variables in the unreduced model included age, sex, race, prior diagnosis of CAA or acute coronary syndrome, hyperlipidemia, hypertension, diabetes, smoking, and cardiac troponin I measurement.

RESULTS

Among the 150 participants, 65.3% (98/150) had invasive coronary angiography and 34.7% (52/150) had coronary computed tomographic angiography. Myocardial infarction occurred in 27.3% (41/150) and coronary revascularization occurred in 26% (39/150) of the participants. Each 10 pg/mL increase in MCP-1 measurement was associated with an odds ratio of 1.12 (95% confidence interval, 1.06-1.19) for obstructive CAA. MCP-1 remained a significant predictor of obstructive CAA and any CAA after adjustment for age, sex, race, traditional cardiac risk factors, and cardiac troponin I.

CONCLUSIONS

MCP-1 is independently associated with CAA among emergency department patients with chest pain.

3 for the Price of 1: Teaching Chest Pain Risk Stratification in a Multidisciplinary, Problem-based Learning Workshop

Introduction

Chest pain is a common chief complaint among patients presenting to health systems and often leads to complex and intensive evaluations. While these patients are often cared for by a multidisciplinary team (primary care, emergency medicine, and cardiology), medical students usually learn about the care of these patients in a fragmented, single-specialty paradigm. The present and future care of patients with chest pain is multidisciplinary, and the education of medical students on the subject should be as well. Our objective was to evaluate the effectiveness of a multidisciplinary, problem-based learning workshop to teach third-year medical students about risk assessment for patients presenting with chest pain, specifically focusing on acute coronary syndromes.

Methods

To create an educational experience consistent with multidisciplinary team-based care, we designed a multidisciplinary, problem-based learning workshop to provide medical students with an understanding of how patients with chest pain are cared for in a systems-based manner to improve outcomes. Participants included third-year medical students (n=219) at a single, tertiary care, academic medical center. Knowledge acquisition was tested in a pre-/post-retention test study design.

Results

Following the workshop, students achieved a 19.7% (95% confidence interval [CI] [17.3-22.2%]) absolute increase in scores on post-testing as compared to pre-testing. In addition, students maintained an 11.1% (95% CI [7.2-15.0%]) increase on a retention test vs. the pre-test.

Conclusion

A multidisciplinary, problem-based learning workshop is an effective method of producing lasting gains in student knowledge about chest pain risk stratification.

Validation of the No Objective Testing Rule and Comparison to the HEART Pathway

BACKGROUND

The no objective testing rule (NOTR) is a decision aid designed to safely identify emergency department (ED) patients with chest pain who do not require objective testing for coronary artery disease.

OBJECTIVES

The objective was to validate the NOTR in a cohort of U.S. ED patients with acute chest pain and compare its performance to the HEART Pathway.

METHODS

A secondary analysis of 282 participants enrolled in the HEART Pathway randomized controlled trial was conducted. Each patient was classified as low risk or at risk by the NOTR. Sensitivity for major adverse cardiac events (MACE) at 30 days was calculated in the entire study population. NOTR and HEART Pathways were compared among patients randomized to the HEART Pathway in the parent trial using McNemar's test and the net reclassification improvement (NRI).

RESULTS

Major adverse cardiac events occurred in 22/282 (7.8%) participants, including no deaths, 16/282 (5.6%) with myocardial infarction (MI), and 6/282 (2.1%) with coronary revascularization without MI. NOTR was 100% (95% confidence interval [CI] = 84.6%-100%) sensitive for MACE and identified 78/282 patients (27.7%, 95% = CI 22.5-33.3%) as low risk. In the HEART Pathway arm (n = 141), both NOTR and HEART Pathway identified all patients with MACE as at risk. Compared to NOTR, the HEART Pathway was able to correctly reclassify 27 patients without MACE as low risk, yielding a NRI of 20.8% (95% CI = 11.3%-30.2%).

CONCLUSIONS

Within a U.S. cohort of ED patients with chest pain, the NOTR and HEART Pathway were 100% sensitive for MACE at 30 days. However, the HEART Pathway identified more patients suitable for early discharge than the NOTR.