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

Ambient Mass Spectrometry and Machine Learning-Based Diagnosis System for Acute Coronary Syndrome

Aims: The purpose of this study is to establish a novel diagnosis system in early acute coronary syndrome (ACS) using probe electrospray ionization-mass spectrometry (PESI-MS) and machine learning (ML) and to validate the diagnostic accuracy. Methods: A total of 32 serum samples derived from 16 ACS patients and 16 control patients were analyzed by PESI-MS. The acquired mass spectrum dataset was subsequently analyzed by partial least squares (PLS) regression to find the relationship between the two groups. A support vector machine, an ML method, was applied to the dataset to construct the diagnostic algorithm. Results: Control and ACS groups were separated into the two clusters in the PLS plot, indicating ACS patients differed from the control in the profile of serum composition obtained by PESI-MS. The sensitivity, specificity, and accuracy of our diagnostic system were all 93.8%, and the area under the receiver operating characteristic curve showed 0.965 (95% CI: 0.84-1). Conclusion: The PESI-MS and ML-based diagnosis system are likely an optimal solution to assist physicians in ACS diagnosis with its remarkably predictive accuracy.

Which Test Should I Order for an Inpatient Evaluation of Cardiac Ischemia?

AbstractTesting for cardiac ischemia, or for the obstructive coronary artery disease (CAD) that causes cardiac ischemia, is common among hospitalized patients. Many testing options exist. Choosing an appropriate test can be challenging and requires accurate risk stratification. Two major categories of testing are available: stress testing (also known as functional testing) and anatomical testing. Stress testing evaluates specifically for ischemia and can be conducted with or without imaging. Anatomical testing visualizes the obstructive CAD that causes ischemia. This article reviews how to choose an appropriate test for the evaluation of cardiac ischemia in the inpatient setting, using case examples to illustrate the considerations involved.

The Impact of an Accelerated Diagnostic Protocol Using Conventional Troponin I for Patients With Cardiac Chest Pain in the Emergency Department

Background

This study strove to assess the impact of the implementation of an accelerated diagnostic protocol (ADP), using shortened serial-testing intervals and a conventional troponin I (c-TnI) test, on emergency department (ED) length of stay (LOS).

Methods

This retrospective cohort study included adults (aged ≥ 18 years) presenting to a Canadian ED with a primary complaint of cardiac chest pain between January 14, 2017 and January 15, 2019. For non-high-risk patients, the troponin delta timing decreased from 6 hours to 3 hours, and a different conventional troponin I level cut-point was implemented on January 15, 2018. The primary outcome was ED LOS. Secondary outcomes included disposition status, consultation proportions, and major adverse cardiac events within 30 days.

Results

A total of 3133 patient interactions were included. Although the overall decrease in median ED LOS was not significant (P = 0.074), a significant reduction occurred in ED LOS (-33 minutes; 95% confidence interval: -53.6 to -12.4 minutes) among patients who were discharged in the post-ADP group. Consultations were unchanged between groups (36.1% before vs 33.8% after; P = 0.17). The major adverse cardiac events outcomes were unchanged across cohorts (15.9% vs 15.3%; P = 0.62).

Conclusions

The implementation of an ADP, with a conventional troponin I test, for cardiac chest pain in a Canadian ED was not associated with a significant reduction of LOS for all patients; however, a significant reduction occurred for patients who were discharged, and the strategy appears safe.

The role of information systems in emergency department decision-making-a literature review

OBJECTIVES

Healthcare providers employ heuristic and analytical decision-making to navigate the high-stakes environment of the emergency department (ED). Despite the increasing integration of information systems (ISs), research on their efficacy is conflicting. Drawing on related fields, we investigate how timing and mode of delivery influence IS effectiveness. Our objective is to reconcile previous contradictory findings, shedding light on optimal IS design in the ED.

MATERIALS AND METHODS

We conducted a systematic review following PRISMA across PubMed, Scopus, and Web of Science. We coded the ISs' timing as heuristic or analytical, their mode of delivery as active for automatic alerts and passive when requiring user-initiated information retrieval, and their effect on process, economic, and clinical outcomes.

RESULTS

Our analysis included 83 studies. During early heuristic decision-making, most active interventions were ineffective, while passive interventions generally improved outcomes. In the analytical phase, the effects were reversed. Passive interventions that facilitate information extraction consistently improved outcomes.

DISCUSSION

Our findings suggest that the effectiveness of active interventions negatively correlates with the amount of information received during delivery. During early heuristic decision-making, when information overload is high, physicians are unresponsive to alerts and proactively consult passive resources. In the later analytical phases, physicians show increased receptivity to alerts due to decreased diagnostic uncertainty and information quantity. Interventions that limit information lead to positive outcomes, supporting our interpretation.

CONCLUSION

We synthesize our findings into an integrated model that reveals the underlying reasons for conflicting findings from previous reviews and can guide practitioners in designing ISs in the ED.

Emergency Department Referral of Patients With Chest Pain for Noninvasive Cardiac Testing and 2-Year Clinical Outcomes

BACKGROUND

Noninvasive cardiac testing (NICT) has been associated with decreased long-term risks of major adverse cardiac events (MACEs) among emergency department patients at high coronary risk. It is unclear whether this association extends to patients without evidence of myocardial injury on initial ECG and cardiac troponin testing.

METHODS

A retrospective cohort study was conducted of patients presenting with chest pain between 2013 and 2019 to 21 emergency departments within an integrated health care system in Northern California, excluding patients with ST-segment-elevation myocardial infarction or myocardial injury by serum troponin testing. To account for confounding by indication, we grouped patient encounters by the NICT referral rate of the initially assigned emergency physician relative to local peers within discrete time periods. The primary outcome was MACE within 2 years. Secondary outcomes were coronary revascularization and MACE, inclusive of all-cause mortality. Associations between the NICT referral group (low, intermediate, or high) and outcomes were assessed using risk-adjusted proportional hazards methods with censoring for competing events.

RESULTS

Among 144 577 eligible patient encounters, the median age was 58 years (interquartile range, 48-68) and 57% were female. Thirty-day NICT referral was 13.0%, 19.9%, and 27.8% in low, intermediate, and high NICT referral groups, respectively, with a good balance of baseline covariates between groups. Compared with the low NICT referral group, there was no significant decrease in the adjusted hazard ratio of MACE within the intermediate (adjusted hazard ratio, 1.08 [95% CI, 1.02-1.14]) or high (adjusted hazard ratio, 1.05 [95% CI, 0.99-1.11]) NICT referral groups. Results were similar for MACE, inclusive of all-cause mortality, and coronary revascularization, as well as subgroup analyses stratified by estimated risk (history, electrocardiogram, age, risk factors, troponin [HEART] score: percent classified as low risk, 48.2%; moderate risk, 49.2%; and high risk, 2.7%).

CONCLUSIONS

Increases in NICT referrals were not associated with changes in the hazard of MACE within 2 years following emergency department visits for chest pain without evidence of acute myocardial injury. These findings further highlight the need for evidence-based guidance regarding the appropriate use of NICT in this population.

European Society of Cardiology 0/1-hour algorithm (high-sensitivity cardiac troponin T) performance across distinct age groups

BACKGROUND

To determine if the European Society of Cardiology 0/1-hour (ESC 0/1-h) algorithm with high-sensitivity cardiac troponin T (hs-cTnT) meets the ≥99% negative predictive value (NPV) safety threshold for 30-day cardiac death or myocardial infarction (MI) in older, middle-aged and young subgroups.

METHODS

We conducted a subgroup analysis of adult emergency department patients with chest pain prospectively enrolled from eight US sites (January 2017 to September 2018). Patients were stratified into rule-out, observation and rule-in zones using the hs-cTnT ESC 0/1-h algorithm and classified as older (≥65 years), middle aged (46-64 years) or young (21-45 years). Patients had 0-hour and 1-hour hs-cTnT measures (Roche Diagnostics) and a History, ECG, Age, Risk factor and Troponin (HEART) score. Fisher's exact tests compared rule-out and 30-day cardiac death or MI rates between ages. NPVs with 95% CIs were calculated for the ESC 0/1-h algorithm with and without the HEART score.

RESULTS

Of 1430 participants, 26.9% (385/1430) were older, 57.4% (821/1430) middle aged and 15.7% (224/1430) young. Cardiac death or MI at 30 days occurred in 12.8% (183/1430). ESC 0/1-h algorithm ruled out 35.6% (137/385) of older, 62.1% (510/821) of middle-aged and 79.9% of (179/224) young patients (p<0.001). NPV for 30-day cardiac death or MI was 97.1% (95% CI 92.7% to 99.2%) among older patients, 98.4% (95% CI 96.9% to 99.3%) in middle-aged patients and 99.4% (95% CI 96.9% to 100%) among young patients. Adding a HEART score increased NPV to 100% (95% CI 87.7% to 100%) for older, 99.2% (95% CI 97.2% to 99.9%) for middle-aged and 99.4% (95% CI 96.6% to 100%) for young patients.

CONCLUSIONS

In older and middle-aged adults, the hs-cTnT ESC 0/1-h algorithm was unable to reach a 99% NPV for 30-day cardiac death or MI unless combined with a HEART score.

TRIAL REGISTRATION NUMBER

NCT02984436.

Performance of the European Society of Cardiology 0/1-hour algorithm with high-sensitivity cardiac troponin T at 90 days among patients with known coronary artery disease

BACKGROUND

The European Society of Cardiology (ESC) 0/1-h high sensitivity troponin T (hs-cTnT) algorithm does not differentiate risk based on known coronary artery disease (CAD: prior myocardial infarction [MI], coronary revascularization, or ≥ 70% coronary stenosis). We recently evaluated its performance among patients with known CAD at 30-days, but little is known about its longer-term risk prediction. The objective of this study is to determine and compare the performance of the algorithm at 90-days among patients with and without known CAD.

METHODS

We performed a pre-planned subgroup analysis of the STOP-CP cohort, which prospectively enrolled ED patients ≥21 years old with symptoms suggestive of ACS without ST-elevation on initial ECG across 8 US sites (1/25/2017-9/6/2018). Participants with 0- and 1-h hs-cTnT measures (Roche, Basel, Switzerland) were stratified into rule-out, observe, and rule-in groups using the ESC 0/1-h algorithm. Algorithm performance was tested among patients with or without known CAD, as determined by the treating provider. The primary outcome was cardiac death or MI at 90-days. Fisher's exact tests were used to compare 90-day event and rule-out rates between patients with and without known CAD. Negative predictive values (NPVs) for 90-day cardiac death or MI with exact 95% confidence intervals were calculated and compared using Fisher's exact test.

RESULTS

The STOP-CP study accrued 1430 patients, of which 31.4% (449/1430) had known CAD. Cardiac death or MI at 90 days was more common in patients with known CAD than in those without [21.2% (95/449) vs. 10.0% (98/981); p < 0.001]. Using the ESC 0/1-h algorithm, 39.6% (178/449) of patients with known CAD and 66.1% (648/981) of patients without known CAD were ruled-out (p < 0.001). Among rule-out patients, 90-day cardiac death or MI occurred in 3.4% (6/178) of patients with known CAD and 1.2% (8/648) without known CAD (p = 0.09). NPV for 90-day cardiac death or MI was 96.6% (95%CI 92.8-98.8) among patients with known CAD and 98.8% (95%CI 97.6-99.5) in patients without known CAD (p = 0.09).

CONCLUSION

Patients with known CAD who were ruled-out using the ESC 0/1-h hs-cTnT algorithm had a high rate of missed 90-day cardiac events, suggesting that the ESC 0/1-h hs-cTnT algorithm may not be safe for use among patients with known CAD.

TRIAL REGISTRATION

High-Sensitivity Cardiac Troponin T to Optimize Chest Pain Risk Stratification (STOP-CP; ClinicalTrials.gov: NCT02984436; https://clinicaltrials.gov/ct2/show/NCT02984436).

Could paramedics use the HEART Pathway to identify patients at low-risk of myocardial infarction in the prehospital setting?

In the Emergency Department, patients with suspected myocardial infarction can be risk stratified using the HEART pathway, which has recently been amended for prehospital use and modified for the incorporation of a high-sensitivity cardiac troponin test. In a prospective analysis, the performance of both HEART pathways in the prehospital setting, with a high-sensitivity cardiac troponin test using 3 different thresholds, was evaluated for major adverse cardiac events at 30 days. We found that both low-risk HEART pathways, when using the most conservative cardiac troponin thresholds, approached but did not reach accepted rule-out performance in the Emergency Department.

Validation of the ACC Expert Consensus Decision Pathway for Patients With Chest Pain

BACKGROUND

The American College of Cardiology (ACC) recently published an Expert Consensus Decision Pathway for chest pain.

OBJECTIVES

The purpose of this study was to validate the ACC Pathway in a multisite U.S.

COHORT

METHODS

An observational cohort study of adults with possible acute coronary syndrome was conducted. Patients were accrued from 5 U.S. Emergency Departments (November 1, 2020, to July 31, 2022). ECGs and 0- and 2-hour high-sensitivity troponin (Beckman Coulter) measures were used to stratify patients according to the ACC Pathway. The primary safety outcome was 30-day all-cause death or myocardial infarction (MI). Efficacy was defined as the proportion stratified to the rule-out zone. Negative predictive value for 30-day death or MI was assessed among the whole cohort and in a subgroup of patients with coronary artery disease (CAD) (prior MI, revascularization, or ≥70% coronary stenosis).

RESULTS

ACC Pathway assessments were complete in 14,395 patients, of whom 51.7% (7,437 of 14,395) were women with a median age of 56 years (Q1-Q3: 44-68 years). Known CAD was present in 23.5% (3,386 of 14,395) and 30-day death or MI occurred in 8.1% (1,168 of 14,395). The ACC Pathway had an efficacy of 48.1% (95% CI: 47.3%-49.0%). Among patients in the rule-out zone, 0.3% (22 of 6,930) had death or MI at 30 days, yielding a negative predictive value of 99.7% (95% CI: 99.5%-99.8%). In patients with known CAD, 20.0% (676 of 3,386) were classified to the rule-out zone, of whom 1.5% (10 of 676) had death or MI.

CONCLUSIONS

The ACC expert consensus decision pathway was safe and efficacious. However, it may not be safe for use among patients with known CAD.

Safety and Effectiveness of the High-Sensitivity Cardiac Troponin HEART Pathway in Patients With Possible Acute Coronary Syndrome

BACKGROUND

The HEART Pathway (History, Electrocardiogram, Age, Risk factors, Troponin) can be used with high-sensitivity cardiac troponin to risk stratify emergency department patients with possible acute coronary syndrome. However, data on whether a high-sensitivity HEART Pathway (hs-HP) are safe and effective is lacking.

METHODS

An interrupted time series study was conducted at 5 North Carolina sites in 26 126 adult emergency department patients being investigated for possible acute coronary syndrome and without ST-segment-elevation myocardial infarction. Patients were accrued into 16-month preimplementation and postimplementation cohorts with a 6-month wash-in phase. Preimplementation (January 2019 to April 2020), the traditional HEART Pathway was used with 0- and 3-hour contemporary troponin measures (Siemens). In the postimplementation period (November 2020 to February 2022), a modified hs-HP was used with 0- and 2-hour high-sensitivity cardiac troponin (Beckman Coulter) measures. The primary safety and effectiveness outcomes were 30-day all-cause death or myocardial infarction and 30-day hospitalizations. These outcomes and early discharge rate (emergency department discharge without stress testing or coronary angiography) were determined from health records and death index data. Outcomes were compared preimplementation versus postimplementation using χ2 tests and multivariable logistic regression to adjust for potential confounders.

RESULTS

Preimplementation and postimplementation cohorts included 12 317 and 13 809 patients, respectively, of them 52.7% (13 767/26 126) were female with a median age of 54 years (interquartile range, 42-66). Rates of 30-day death or MI were 6.8% (945/13 809) postimplementation and 7.7% (948/12 317) preimplementation (adjusted odds ratio, 1.00 [95% CI, 0.90-1.11]). hs-HP implementation was associated with 19.9% (95% CI, 18.7%-21.1%) higher early discharges (post versus pre: 63.6% versus 43.7%; adjusted odds ratio, 2.22 [95% CI, 2.10-2.35]). The hs-HP was also associated with 16.1% (95% CI, 14.9%-17.3%) lower 30-day hospitalizations (postimplementation versus preimplementation, 31.4% versus 47.5%; adjusted odds ratio, 0.51 [95% CI, 0.48-0.54]). Among early discharge patients, death or myocardial infarction occurred in 0.5% (41/8780) postimplementation versus 0.4% (22/5383) preimplementation (P=0.61).

CONCLUSIONS

hs-HP implementation is associated with increased early discharges without increasing adverse events. These findings support the use of a modified hs-HP to improve chest pain care.

Performance of the 0/2-hour high-sensitivity cardiac troponin T diagnostic protocol in a multisite United States cohort

BACKGROUND

The diagnostic performance of the high-sensitivity troponin T (hs-cTnT) 0/2-h algorithm is unclear among U.S. emergency department (ED) patients with acute chest pain.

METHODS

A preplanned subgroup analysis of the STOP-CP cohort study was conducted. Participants with 0- and 2-h hs-cTnT measures prospectively enrolled at eight U.S. EDs from January 2017 to September 2018 were stratified into rule-out, observation, and rule-in zones using the hs-cTnT 0/2-h algorithm alone and combined with the history, electrocardiogram, age, and risk factor (HEAR) score. The primary outcome was adjudicated 30-day cardiac death or myocardial infarction (CDMI). The sensitivity and negative predictive value (NPV) of the 0/2-h rule-out zone and specificity and positive predictive value (PPV) of the rule-in zone for 30-day CDMI were calculated.

RESULTS

Of the 1307 patients accrued, 53.6% (700/1307) were male and 58.6% (762/1307) were White, with a mean ± SD age of 57.5 ± 12.7 years. At 30 days, CDMI occurred in 12.9% (168/1307) of participants. The 0/2-h algorithm ruled out 61.4% (802/1307) of patients. Among rule-out patients, 1.9% (15/802) experienced 30-day CDMI, resulting in a sensitivity of 91.1% (95% confidence interval [CI] 85.7%-94.9%) and NPV of 98.1% (95% CI 96.9%-98.9%). The 0/2-h algorithm ruled in 12.4% (162/1307) patients of whom 61.7% (100/162) experienced 30-day CDMI. The rule-in zone specificity was 94.6% (95% CI 93.1%-95.8%) and PPV was 61.7% (95% CI 53.8%-69.2%) for 30-day CDMI. The 0/2-h algorithm combined with HEAR score ruled out 30.7% (401/1307) of patients with a sensitivity and NPV for 30-day CDMI of 98.2% (95% CI 94.9%-99.6%) and 99.3% (95% CI 97.8%-99.8%), respectively.

CONCLUSIONS

The hs-cTnT 0/2-h algorithm ruled out most patients. With NPV of <99% for 30-day CDMI, the hs-cTnT 0/2-h algorithm, many emergency physicians may not consider it safe to use for U.S. ED patients. When combined with a low-risk HEAR score, NPV was >99% for 30-day CDMI at the cost of reduced efficacy.

Sex and race differences in the performance of the European Society of Cardiology 0/1-h algorithm with high-sensitivity troponin T

The diagnostic performance of the high-sensitivity troponin T (hs-cTnT) European Society of Cardiology (ESC) 0/1-h algorithm in sex and race subgroups of US Emergency Department (ED) patients is unclear. A pre-planned subgroup analysis of the STOP-CP cohort study was conducted. Participants with 0- and 1-h hs-cTnT measures from eight US EDs (1/2017 to 9/2018) were stratified into rule-out, observation, and rule-in zones using the hs-cTnT ESC 0/1 algorithm. The primary outcome was adjudicated 30-day cardiac death or MI. The proportion with the primary outcome in each zone was compared between subgroups with Fisher's exact tests. The negative predictive value (NPV) of the ESC 0/1 rule-out zone for 30-day CDMI was calculated and compared between subgroups using Fisher's exact tests. Of the 1422 patients enrolled, 54.2% (770/1422) were male and 58.1% (826/1422) white with a mean age of 57.6 ± 12.8 years. At 30 days, cardiac death or myocardial infarction (MI) occurred in 12.9% (183/1422) of participants. Among patients stratified to the rule-out zone, 30-day cardiac death or MI occurred in 1.1% (5/436) of women versus 2.1% (8/436) of men (p = .40) and 1.2% (4/331) of non-white patients versus 1.8% (9/490) of white patients (p = .58). The NPV for 30-day cardiac death or MI was similar among women versus men (98.9% [95% confidence interval, CI: 97.3-99.6] vs. 97.9% [95% CI: 95.9-99.1]; p = .40) and among white versus non-white patients (98.8% [95% CI: 96.9-99.7] vs. 98.2% [95% CI: 96.5-99.2]; p = .39). NPVs <99% in each subgroup suggest the hs-cTnT ESC 0/1-h algorithm may not be safe for use in US EDs. Trial Registration: High-Sensitivity Cardiac Troponin T to Optimize Chest Pain Risk Stratification (STOP-CP; ClinicalTrials.gov: NCT02984436; https://clinicaltrials.gov/ct2/show/NCT02984436).

Preventive Cardiovascular Care for Hypercholesterolemia in US Emergency Departments: A National Missed Opportunity

BACKGROUND

Hypercholesterolemia (HCL) affects nearly half of Emergency Department (ED) patients who present with possible acute coronary syndrome (ACS). However, it is unknown whether US ED providers obtain lipid panels, calculate 10-year atherosclerotic cardiovascular disease (ASCVD) risk, and prescribe cholesterol-lowering medications for these patients.

METHODS

We conducted a nationwide cross-sectional ED survey from April 18, 2023, to May 12, 2023. An electronic survey assessing current preventive HCL care practices for patients being evaluated for ACS. A convenience sample was obtained by sharing the survey with ED medical directors, chairs, and senior leaders using emergency medicine professional organization listservs and snowball sampling. Responding EDs were categorized as being associated with an academic medical center (AMC) or not (non-AMC).

RESULTS

During the 4-week study period, 110 EDs (50 AMC and 60 non-AMC EDs) across 39 states responded. Just 1.8% (2/110) stated that their providers obtain a lipid panel on at least half of patients with possible ACS and only one ED (0.9%) responded that its providers calculate 10-year ASCVD risk and prescribe cholesterol medication for the majority of eligible patients. Most reported never obtaining lipid panels (60.9%, 67/110), calculating 10-year ASCVD risk (55.5%, 61/110), or prescribing cholesterol-lowering medications (52.7%, 58/110).

CONCLUSIONS

The vast majority of US ED providers do not provide preventive cardiovascular care for patients presenting with possible ACS. Most ED providers do not evaluate for HCL, calculate ASCVD risk, or prescribe cholesterol-lowering medications for these patients.

Comprehensive validation of early diagnostic algorithms for myocardial infarction in the emergency department

OBJECTIVE

To comprehensively evaluate diagnostic algorithms for myocardial infarction using a high-sensitivity cardiac troponin I (hs-cTnI) assay.

PATIENTS AND METHODS

We prospectively enrolled patients with suspected myocardial infarction without ST-segment elevation from nine emergency departments in Japan. The diagnostic algorithms evaluated a) based on hs-cTnI alone, such as the European Society of Cardiology (ESC) 0/1-h or 0/2-h and High-STEACS pathways; or b) used medical history and physical findings, such as the ADAPT, EDACS, HEART, and GRACE pathways. We evaluated the negative predictive value (NPV), sensitivity as safety measures, and proportion of patients classified as low or high-risk as an efficiency measure for a primary outcome of type 1 myocardial infarction or cardiac death within 30 days.

RESULTS

We included 437 patients, and the hs-cTnI was collected at 0 and 1 hours in 407 patients and at 0 and 2 hours in 394. The primary outcome occurred in 8.1% (33/407) and 6.9% (27/394) of patients, respectively. All the algorithms classified low-risk patients without missing those with the primary outcome, except for the GRACE pathway. The hs-cTnI-based algorithms classified more patients as low-risk: the ESC 0/1-h 45.7%; the ESC 0/2-h 50.5%; the High-STEACS pathway 68.5%, than those using history and physical findings (15-30%). The High-STEACS pathway ruled out more patients (20.5%) by hs-cTnI measurement at 0 hours than the ESC 0/1-h and 0/2-h algorithms (7.4%).

CONCLUSIONS

The hs-cTnI algorithms, especially the High-STEACS pathway, had excellent safety performance for the early diagnosis of myocardial infarction and offered the greatest improvement in efficiency.

Derivation of a HEAR Pathway for Emergency Department Chest Pain Patients to Safely Avoid a Second Troponin Test

The study aims to develop a decision pathway based on HEAR score and 0 h high-sensitivity cardiac troponin T (hs-cTnT) to safely avoid a second troponin test for suspected non-ST elevation myocardial infarction (NSTEMI) in emergency departments. A HEAR score consists of history, electrocardiogram, age, and risk factors. A HEAR pathway is established using a Bayesian approach based on a predefined safety threshold of NSTEMI prevalence in the rule-out group. In total, 7131 patients were retrospectively enrolled, 582 (8.2%) with index visit NSTEMI and 940 (13.2%) with 180-day major adverse cardiovascular events (MACE). For patients with a low-risk HEAR score (0 to 2) and low 0 h hs-cTnT (<14 ng/L), the HEAR pathway recommends early discharge without further testing. After the HEAR pathway had been applied to rule out NSTEMI, the negative predictive value of index visit NSTEMI was 100.0% (95% CI, 99.8% to 100.0%) and false-negative rate of 180-day MACE was 0.40% (95% CI, 0.18% to 0.87%). Compared with the 0 h hs-cTnT < limit of detection (LoD) strategy (<5 ng/L), the HEAR pathway could correctly reclassify 1298 patients without MACE as low risk and lead to a 18.2% decrease (95% CI, 17.4-19.1%) in the need for a second troponin test. The HEAR pathway may lead to a substantial and safe reduction in repeated troponin test for emergency department patients with suspected NSTEMI.

Multicenter analysis to assess risk of major adverse cardiac events in patients undergoing high-sensitivity troponin testing in the emergency department

Study hypothesis

Our objective was to evaluate 30-day major adverse cardiac events (MACE) in emergency department (ED) patients with normal high-sensitivity troponins (hs-trop). We hypothesized that MACE rates would be <1% in patients with (1) two normal troponins regardless of change in troponin (delta) and (2) index hs-trop below the limit of quantitation (LOQ) regardless of the institution modified HEART score.

Methods

This was a multicenter, retrospective, cohort study of adult patients who presented to 1 of 18 EDs between July 2020 and April 2021 with acute coronary syndrome as defined by an institutional-modified HEART score completed by their treating physician or midlevel, no evidence of ST-elevation myocardial infarction, and an index or serial gender-adjusted hs-trop within normal limits. The primary outcome was MACE within 30 days of index ED encounter. A detailed case review was then performed for those patients experiencing a MACE.

Results

Of the 9084 patients who had single or serial normal troponins, 31 (0.34%; confidence interval [CI] 0.23%-0.48%) experienced MACE. Of the 6140 patients with 2 normal hs-trop and a delta (change in troponin) <4, 27 patients (0.44%; CI 0.29%-0.64%) experienced MACE. Only 1 of the 69 patients with 2 normal hs-trop results but delta (change in troponin) ≥ 4 (1.45%; CI 0.04%-7.81%) suffered MACE. This patient was classified as non-low risk by our institutional HEART score. Of 7498 patients with an index hs-trop 

Conclusion

Patients with 2 normal hs-trop values in the ED are unlikely to suffer 30-day MACE. Although it remains unclear whether patients with delta (change in troponin) ≥4 despite normal troponins will have a 30-day MACE, this situation is rare. Additionally, a single index hs-trop <6 ng/L demonstrated a low risk for 30-day MACE independent of the institutional HEART score.

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Affiliation(s)

Victoria Serven Department of Emergency MedicineAtrium Health's Carolinas Medical CenterCharlotteNorth CarolinaUSA
Kamala Swayampakala Sanger Heart & Vascular InstituteAtrium HealthCharlotteNorth CarolinaUSA
Christy Lesassier Sanger Heart & Vascular InstituteAtrium HealthCharlotteNorth CarolinaUSA
Tyler Siekmann Department of Emergency MedicineAtrium Health's Carolinas Medical CenterCharlotteNorth CarolinaUSA
Gabriel Rivera‐Camacho Department of Emergency MedicineAtrium Health's Carolinas Medical CenterCharlotteNorth CarolinaUSA
Santosh Rao Sanger Heart & Vascular InstituteAtrium HealthCharlotteNorth CarolinaUSA
David Matthew Sullivan Information and Analytics ServicesAtrium HealthCharlotteNorth CarolinaUSA
Harvey Pendell Meyers Department of Emergency MedicineAtrium Health's Carolinas Medical CenterCharlotteNorth CarolinaUSA
David Pearson Department of Emergency MedicineAtrium Health's Carolinas Medical CenterCharlotteNorth CarolinaUSA

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Early emergency department discharge for intermediate heart score patients presenting for chest pain

Study Objective

The use of the HEART score to risk stratify patients for short-term major adverse cardiac events in the emergency department (ED) setting is well established. Although discharge to home for low-risk HEART score patients is widely accepted as safe practice, there are limited outcomes data on moderate-risk HEART score patients discharged to home. We investigated the safety of discharging moderate-risk HEART score patients to home from the ED with established early cardiology follow-up.

Methods

We performed a retrospective cohort analysis of patients presenting to the ED with chest pain from April 2020 through December 2020. Patients were evaluated in the ED and underwent serial conventional troponin testing and electrocardiogram (ECG). Clinicians calculated a HEART score and employed shared decision-making with moderate-risk patients (score 4-6), offering hospital admission versus discharge home with a formalized process for rapid cardiology follow-up (within 2 business days). We assessed the frequency of acute myocardial infarction or death at 30 days and before cardiology follow-up.

Results

During our study period, 2939 patient encounters were screened for chest pain. Of these, 333 of 547 eligible moderate-risk HEART score patients were referred for rapid follow-up. The median time to follow-up appointment was 2.9 business days (interquartile range 1.3, 6.5), and 264 (79%) of patients kept their follow-up appointment. One patient (0.3%) suffered death within 30 days, before cardiology follow-up. There were no myocardial infarctions.

Conclusions

These results suggest that moderate-risk HEART score patients may be considered for discharge from the ED with rapid cardiology follow-up. Formalizing processes to facilitate these early evaluations may represent a viable alternative to hospital admission, without diminishing patient outcomes.

Race differences in cardiac testing rates for patients with chest pain in a multisite cohort

BACKGROUND

Identifying and eliminating racial health care disparities is a public health priority. However, data evaluating race differences in emergency department (ED) chest pain care are limited.

METHODS

We conducted a secondary analysis of the High-Sensitivity Cardiac Troponin T to Optimize Chest Pain Risk Stratification (STOP-CP) cohort, which prospectively enrolled adults with symptoms suggestive of acute coronary syndrome without ST-elevation from eight EDs in the United States from 2017 to 2018. Race was self-reported by patients and abstracted from health records. Rates of 30-day noninvasive testing (NIT), cardiac catheterization, revascularization, and adjudicated cardiac death or myocardial infarction (MI) were determined. Logistic regression was used to evaluate the association between race and 30-day outcomes with and without adjustment for potential confounders.

RESULTS

Among 1454 participants, 42.3% (615/1454) were non-White. At 30 days NIT occurred in 31.4% (457/1454), cardiac catheterization in 13.5% (197/1454), revascularization in 6.0% (87/1454), and cardiac death or MI in 13.1% (190/1454). Among Whites versus non-Whites, NIT occurred in 33.8% (284/839) versus 28.1% (173/615; odds ratio [OR] 0.76, 95% confidence interval [CI] 0.61-0.96) and catheterization in 15.9% (133/839) versus 10.4% (64/615; OR 0.62, 95% CI 0.45-0.84). After covariates were adjusted for, non-White race remained associated with decreased 30-day NIT (adjusted OR [aOR] 0.71, 95% CI 0.56-0.90) and cardiac catheterization (aOR 0.62, 95% CI 0.43-0.88). Revascularization occurred in 6.9% (58/839) of Whites versus 4.7% (29/615) of non-Whites (OR 0.67, 95% CI 0.42-1.04). Cardiac death or MI at 30 days occurred in 14.2% of Whites (119/839) versus 11.5% (71/615) of non-Whites (OR 0.79 95% CI 0.57-1.08). After adjustment there was still no association between race and 30-day revascularization (aOR 0.74, 95% CI 0.45-1.20) or cardiac death or MI (aOR 0.74, 95% CI 0.50-1.09).

CONCLUSIONS

In this U.S. cohort, non-White patients were less likely to receive NIT and cardiac catheterization compared to Whites but had similar rates of revascularization and cardiac death or MI.

Flexible-Interval High-Sensitivity Troponin Velocity for the Detection of Acute Coronary Syndromes

Many algorithms for emergency department (ED) evaluation of acute coronary syndrome (ACS) using high-sensitivity troponin assays rely on the detection of a "delta," the difference in concentration over a predetermined interval, but collecting specimens at specific times can be difficult in the ED. We evaluate the use of troponin "velocity," the rate of change of troponin concentration over a flexible short interval for the prediction of major adverse cardiac events (MACEs) at 30 days. We conducted a prospective, observational study on a convenience sample of 821 patients who underwent ACS evaluation at a high-volume, urban ED. We determined the diagnostic performance of a novel velocity-based algorithm and compared the performance of 1- and 2-hour algorithms adapted from the European Society of Cardiology (ESC) using delta versus velocity. A total of 7 of 332 patients (2.1%) classified as low risk by the velocity-based algorithm experienced a MACE by 30 days compared with 35 of 221 (13.8%) of patients classified as greater than low risk, yielding a sensitivity of 83.3% (95% confidence interval [CI] 68.6% to 93.0%) and negative predictive value (NPV) of 97.9% (95% CI 95.9% to 98.9%). The ESC-derived algorithms using delta or velocity had NPVs ranging from 98.4% (95% CI 96.4% to 99.3%) to 99.6% (95% CI 97.0% to 99.9%) for 30-day MACEs. The NPV of the novel velocity-based algorithm for MACE at 30 days was borderline, but the substitution of troponin velocity for delta in the framework of the ESC algorithms performed well. In conclusion, specimen collection within strict time intervals may not be necessary for rapid evaluation of ACS with high-sensitivity troponin.

Use of the HEAR Score for 30-Day Risk-Stratification in Emergency Department Patients

BACKGROUND

The 2021 American College of Cardiology/American Heart Association chest pain guidelines recommend risk scores such as HEAR (History, Electrocardiogram, Age, Risk factors) for short-term risk stratification, yet limited data exist integrating them with high-sensitivity cardiac troponin T (hs-cTnT).

METHODS

Retrospective, multicenter (n = 2), observational, US cohort study of consecutive emergency department patients without ST-elevation myocardial infarction who had at least one hs-cTnT (limit of quantitation [LoQ] <6 ng/L, and sex-specific 99th percentiles of 10 ng/L for women and 15 ng/L for men) measurement on clinical indications in whom HEAR scores (0-8) were calculated. The composite major adverse cardiovascular event (MACE) outcome was 30-day prognosis.

RESULTS

Among 1979 emergency department patients undergoing hs-cTnT measurement, 1045 (53%) were low risk (0-3), 914 (46%) intermediate risk (4-6), and 20 (1%) high risk (7-8) based on HEAR scores. HEAR scores were not associated with increased risk of 30-day MACE in adjusted analyses. Patients with quantifiable hs-cTnT (LoQ-99th) had an increased risk for 30-day MACE (3.4%) irrespective of HEAR scores. Those with serial hs-cTnT <99th percentile remained at low risk (range 0%-1.2%) across all HEAR score strata. Higher scores were not associated with long-term (2-year) events.

CONCLUSIONS

HEAR scores are of limited value in those with baseline hs-cTnT 99th percentile to define short-term prognosis. In those with baseline quantifiable hs-cTnT within the reference range (<99th percentile), a higher risk (>1%) for 30-day MACE exists even in those with low HEAR scores. With serial hs-cTnT measurements, HEAR scores overestimate risk when hs-cTnT remains <99th percentile.

Modification of HEART Pathway for Patients With Chest Pain: A Korean Perspective

BACKGROUND AND OBJECTIVES

The History, Electrocardiography, Age, Risk factors, and Troponin (HEART) pathway was developed to identify patients at low risk of a major adverse cardiac event (MACE) among patients presenting with chest pain to the emergency department.

METHODS

We modified the HEART pathway by replacing the Korean cut-off of 25 kg/m² with the conventional threshold of 30 kg/m² in the definition of obesity among risk factors. The primary outcome was a MACE within 30 days, which included acute myocardial infarction, primary coronary intervention, coronary artery bypass grafting, and all-cause death.

RESULTS

Of the 1,304 patients prospectively enrolled, MACE occurred in 320 (24.5%). The modified HEART pathway identified 37.3% of patients as low-risk compared with 38.3% using the HEART pathway. Of the 500 patients classified as low-risk with HEART pathway, 8 (1.6%) experienced MACE, and of the 486 low-risk patients with modified HEART pathway, 4 (0.8%) experienced MACE. The modified HEART pathway had a sensitivity of 98.8%, a negative predictive value (NPV) of 99.2%, a specificity of 49.0%, and a positive predictive value (PPV) of 38.6%, compared with the original HEART pathway, with a sensitivity of 97.5%, a NPV of 98.4%, a specificity of 50.0%, and a PPV of 38.8%.

CONCLUSIONS

When applied to Korean population, modified HEART pathway could identify patients safe for early discharge more accurately by using body mass index cut-off levels suggested for Koreans.

Emergency Department Observation Unit Patients Want Evaluation and Treatment for Hypercholesterolemia: A Health Belief Model Study

BACKGROUND

Hypercholesterolemia (HCL) is common among emergency department (ED) and ED observation unit (EDOU) patients with chest pain but is not typically addressed in these settings. The objective of this study was to assess patient attitudes towards EDOU-based HCL care using the Health Belief Model.

METHODS

We conducted a cross-sectional survey study among 100 EDOU patients ≥18 years-old evaluated for chest pain in the EDOU of a tertiary care center from September 1, 2020, to November 01, 2021. Five-point Likert-scale surveys were used to assess each Health Belief Model domain: Cues to Action, Perceived Susceptibility, Perceived Barriers, Perceived Self-Efficacy, and Perceived Benefits. Responses were categorized as agree or do not agree.

RESULTS

The participants were 49.0% (49/100) female, 39.0% (39/100) non-white, and had a mean age of 59.0 ± 12.4 years. Most (83.0% [83/100, 95% confidence interval (CI), 74.2%-89.8%]) agreed the EDOU is an appropriate place for HCL education and 52.0% (52/100, 95% CI, 41.8%-62.1%) were interested in talking with their EDOU care team about HCL. Regarding Perceived Susceptibility, 88.0% (88/100, 95% CI, 80.0%-93.6%) believed HCL to be bad for their health, while 41.0% (41/100, 95% CI, 31.3%-51.3%) believed medication costs could be a barrier. For Perceived Self-Efficacy, 76.0% (76/100, 95% CI, 66.4%-84.0%) were receptive to taking medications. Overall, 95.0% (95/100, 95% CI, 88.7%-98.4%) believed managing HCL would benefit their health.

CONCLUSIONS

This Health Belief Model-based survey indicates high patient interest in EDOU-initiated HCL care. Patients reported high rates of Perceived Susceptibility, Self-Efficacy, and Benefits and a minority found HCL therapy costs a barrier.

Comparative Effectiveness of Coronary CT Angiography and Standard of Care for Evaluating Acute Chest Pain: A Living Systematic Review and Meta-Analysis

Purpose

To perform a living systematic review and meta-analysis of randomized controlled trials comparing the effectiveness of coronary CT angiography (CCTA) and standard of care (SOC) in the evaluation of acute chest pain (ACP).

Materials and Methods

Multiple electronic databases were systematically searched, with the most recent search conducted on October 31, 2022. Studies were stratified into two groups according to the pretest probability for acute coronary syndrome (group 1 with predominantly low-to-intermediate risk vs group 2 with high risk). A meta-regression analysis was also conducted using participant risk, type of SOC used, and the use or nonuse of high-sensitivity troponins as independent variables.

Results

The final analysis included 22 randomized controlled trials (9379 total participants; 4956 assigned to CCTA arms and 4423 to SOC arms). There was a 14% reduction in the length of stay and a 17% reduction in immediate costs for the CCTA arm compared with the SOC arm. In group 1, the length of stay was 17% shorter and costs were 21% lower using CCTA. There was no evidence of differences in referrals to invasive coronary angiography, myocardial infarction, mortality, rate of hospitalization, further stress testing, or readmissions between CCTA and SOC arms. There were more revascularizations (relative risk, 1.45) and medication changes (relative risk, 1.33) in participants with low-to-intermediate acute coronary syndrome risk and increased radiation exposure in high-risk participants (mean difference, 7.24 mSv) in the CCTA arm compared with the SOC arm. The meta-regression analysis found significant differences between CCTA and SOC arms for rate of hospitalization, further stress testing, and medication changes depending on the type of SOC (P < .05).

Conclusion

The results support the use of CCTA as a safe, rapid, and less expensive in the short term strategy to exclude acute coronary syndrome in low- to intermediate-risk patients presenting with acute chest pain.Keywords: Acute Coronary Syndrome, Chest Pain, Emergency Department, Coronary Computed Tomography, Usual Care Supplemental material is available for this article. Published under a CC BY 4.0 license.

Impact of Care Interventions on the Survival of Patients with Cardiac Chest Pain

BACKGROUND

Chest pain is considered the second most frequent complaint among patients seeking emergency services. However, there is limited information in the literature about how the care provided to patients with chest pain, when being attended to in the emergency room, influences their clinical outcomes.

AIMS

To assess the relationship between care interventions performed on patients with cardiac chest pain and their immediate and late clinical outcomes and to identify which care interventions were essential to survival.

METHODS

In this retrospective study. We analyzed 153 medical records of patients presenting with chest pain at an emergency service center, São Paulo, Brazil. Participants were divided into two groups: (G1) remained hospitalized for a maximum of 24 h and (G2) remained hospitalized for between 25 h and 30 days.

RESULTS

Most of the participants were male 99 (64.7%), with a mean age of 63.2 years. The interventions central venous catheter, non-invasive blood pressure monitoring, pulse oximetry, and monitoring peripheral perfusion were commonly associated with survival at 24 h and 30 days. Advanced cardiovascular life support and basic support life (p = 0.0145; OR = 8053; 95% CI = 1385-46,833), blood transfusion (p < 0.0077; OR = 34,367; 95% CI = 6489-182,106), central venous catheter (p < 0.0001; OR = 7.69: 95% CI 1853-31,905), and monitoring peripheral perfusion (p < 0.0001; OR = 6835; 95% CI 1349-34,634) were independently associated with survival at 30 days by Cox Regression.

CONCLUSIONS

Even though there have been many technological advances over the past decades, this study demonstrated that immediate and long-term survival depended on interventions received in an emergency room for many patients.

Rarely tested or treated but highly prevalent: Hypercholesterolemia in emergency department observation unit patients with chest pain

BACKGROUND

Hypercholesterolemia (HCL) is common among Emergency Department (ED) patients with chest pain but is typically not addressed in this setting. This study aims to determine whether a missed opportunity for Emergency Department Observation Unit (EDOU) HCL testing and treatment exists.

METHODS

We conducted a retrospective observational cohort study of patients ≥18 years old evaluated for chest pain in an EDOU from 3/1/2019-2/28/2020. The electronic health record was used to determine demographics and if HCL testing or treatment occurred. HCL was defined by self-report or clinician diagnosis. Proportions of patients receiving HCL testing or treatment at 1-year following their ED visit were calculated. HCL testing and treatment rates at 1-year were compared between white vs. non-white and male vs. female patients using multivariable logistic regression models including age, sex, and race.

RESULTS

Among 649 EDOU patients with chest pain, 55.8% (362/649) had known HCL. Among patients without known HCL, 5.9% (17/287, 95% CI 3.5-9.3%) had a lipid panel during their index ED/EDOU visit and 26.5% (76/287, 95% CI 21.5-32.0%) had a lipid panel within 1-year of their initial ED/EDOU visit. Among patients with known or newly diagnosed HCL, 54.0% (229/424, 95% CI 49.1-58.8%) were on treatment within 1-year. After adjustment, testing rates were similar among white vs. non-white patients (aOR 0.71, 95% CI 0.37-1.38) and men vs. women (aOR 1.32, 95% CI 0.69-2.57). Treatment rates were similar among white vs. non-white (aOR 0.74, 95% CI 0.53-1.03) and male vs. female (aOR 1.08, 95% CI 0.77-1.51) patients.

CONCLUSIONS

Few patients were evaluated for HCL in the ED/EDOU or outpatient setting after their ED/EDOU encounter and only 54% of patients with HCL were on treatment during the 1-year follow-up period after the index ED/EDOU visit. These findings suggest a missed opportunity to reduce cardiovascular disease risk exists by evaluating and treating HCL in the ED or EDOU.

History, ECG, Risk Factors (HER) Scoring for Cardiac Risk Stratification in Patients <45 Years of Age Presenting With Chest Pain

Background Chest pain is a common chief complaint of patients presenting to the emergency department. Acute coronary syndrome (ACS) is found to be the etiology of this symptom in a minority of these patient encounters. This study aimed to determine the utility of using the History, ECG, Risk Factors (HER) components of the History, ECG, Age, Risk Factors, Troponin (HEART) score in ruling out 30-day Major Adverse Cardiac Event (MACE), ACS, ventricular tachycardia, and ventricular fibrillation in patients aged less than 45. Additionally, the utility of this score in ruling out a positive troponin was investigated as well. Methodology This is a retrospective chart review study that examined a consecutive cohort of 7,724 patients presenting with chest pain to the 11 emergency departments of a single healthcare system over a two-year period (January 2019 to December 2020). HER scores of 0 to 1 were categorized as negative (-) and scores of two or greater were categorized as positive (+). Sensitivity, specificity, and predictive values were calculated for the relationship between HER score positivity and primary cardiac disease and troponin results. Results Test characteristics of HER scoring for significant primary cardiac disease in patients between 18 and 45 years of age presenting with undifferentiated chest pain were sensitivity of 88.0 (CI = 80.0-94.0), specificity of 72.6 (CI = 71.8-73.8), positive predictive value of 3.1 (CI = 2.4-3.9), and negative predictive value of 99.8 (CI = 99.7-99.9). Furthermore, an HER score >1 was neither sensitive nor specific in predicting a positive troponin (sensitivity = 80, CI = 71.9-86; specificity = 71.3, CI = 70.3-72.3). However, the negative predictive value of an HER score of 0-1 was 99.5 (CI = 99.3-99.7) and the positive predictive value was 4.7 (CI = 3.9-5.7). Conclusions According to this study, when evaluating young patients who are deemed to have a subjectively non-highly suspicious history, who have minimal risk factors, and who have an ECG without significant ST deviation, troponin testing is low yield in the risk stratification of patients under the age of 45 for serious primary cardiac disease.

Association of physician malpractice claims rates with admissions for low-risk chest pain

Background

Chest pain accounts for 5% of all emergency department visits and accounts for the highest malpractice payout against emergency physicians. To clarify the impact of defensive medicine, we assessed whether admission rates of low-risk chest pain patients are associated with malpractice claims rates.

Methods

A cross-sectional time-series analysis of state-year level malpractice claims rates, admission rates for low-risk chest pain (LRCP; requiring ED physician discretion), and admission rates for acute myocardial infarction (AMI; requiring minimal physician judgment for admission, used as a control) from 2008 to 2017 was performed. Admission rates were derived from Optum's deidentified Clinformatics Data Mart Database. LRCP visits were defined by primary ICD-9 or ICD-10 codes of 786.5, R07.9, or R07.89; length of stay of 2 or fewer days; and no previous major cardiac diagnosis and AMI visits with ICD-9 or ICD-10 codes 410, I21.3, or I121.9. Malpractice claims rates (MPCRs) were derived from the National Practitioner Database (NPD). The association between state-year level MPCR and admission rates for LRCP and AMI was estimated using state fixed-effects models. Standardized costs were inflation adjusted and are expressed in US dollar rate as of 2019.

Results

There were 40,482,813 ED visits during the 10-year study period, of which 2,275,757 (5.6%) were for chest pain, and 1,163,881 met LRCP criteria. Mean age of LRCP patients was 67.8 years, 60.9% were female, and 16.6% were hospitalized, at a mean cost of $17,120. During the same period, 75,266 (0.2%) visits were for AMI, with 87% admitted. The MPCR by state-year varied widely, from 2.6 to 8.6 claims per 100,000 population. A state fixed-effects model showed that an additional physician malpractice claim per 100,000 population was associated with a 3.66% (95% CI 2.02%-5.30%) increase in the admission rate of LRCP. An analogous model showed no association between MPCR and admission rates for AMI (-1.52%, 95% CI -4.06% to 1.02%).

Conclusion

Higher MPCRs are associated with increased admission rates for LRCP, at substantial cost, which may be attributable to defensive medicine in the ED.

Chest pain observation unit: A missed opportunity to initiate smoking cessation therapy

BACKGROUND

Emergency Department Observation Unit (EDOU) patients with chest pain have a high prevalence of smoking, a key cardiovascular disease risk factor. While in the EDOU, there is an opportunity to initiate smoking cessation therapy (SCT), but this is not standard practice. This study aims to describe the missed opportunity for EDOU-initiated SCT by determining the proportion of smokers who receive SCT in the EDOU and within 1-year of EDOU discharge and to evaluate if SCT rates vary by race or sex.

METHODS

We performed an observational cohort study of patients ≥18 years old being evaluated for chest pain in a tertiary care center EDOU from 3/1/2019-2/28/2020. Demographics, smoking history, and SCT were determined by electronic health record review. Emergency, family medicine, internal medicine, and cardiology records were reviewed to determine if SCT occurred within 1-year of their initial visit. SCT was defined as behavioral interventions or pharmacotherapy. Rates of SCT in the EDOU, 1-year follow-up period, and the EDOU through 1-year of follow-up were calculated. SCT rates from the EDOU through 1-year were compared between white vs. non-white and male vs. female patients using a multivariable logistic regression model including age, sex, and race.

RESULTS

Among 649 EDOU patients, 24.0% (156/649) were smokers. These patients were 51.3% (80/156) female and 46.8% (73/156) white, with a mean age of 54.4 ± 10.5 years. From the EDOU encounter through 1-year of follow-up, only 33.3% (52/156) received SCT. In the EDOU, 16.0% (25/156) received SCT. During the 1-year follow-up period, 22.4% (35/156) had outpatient SCT. After adjusting for potential confounders, SCT rates from the EDOU through 1-year were similar among whites vs. non-whites (aOR 1.19, 95% CI 0.61-2.32) and males vs. females (aOR 0.79, 95% CI 0.40-1.56).

CONCLUSIONS

SCT was rarely initiated in the EDOU among chest pain patients who smoke and most patients who did not receive SCT in the EDOU never received SCT at 1-year of follow-up. Rates of SCT were similarly low among race and sex subgroups. These data suggest an opportunity exists to improve health by initiating SCT in the EDOU.

Variation in ACS patient hospital resource utilization: Is it time for advanced NSTEMI risk stratification in the ED?

OBJECTIVES

A majority of patients who experience acute coronary syndrome (ACS) initially receive care in the emergency department (ED). Guidelines for care of patients experiencing ACS, specifically ST-segment elevation myocardial infarction (STEMI) are well defined. We examine the utilization of hospital resources between patients with NSTEMI as compared to STEMI and unstable angina (UA). We then make the case that as NSTEMI patients are the majority of ACS cases, there is a great opportunity to risk stratify these patients in the emergency department.

MATERIALS AND METHODS

We examined hospital resource utilization measure between those with STEMI, NSTEMI, and UA. These included hospital length of stay (LOS), any intensive care unit (ICU) care time, and in-hospital mortality.

RESULTS AND CONCLUSIONS

The sample included 284,945 adult ED patients, of whom 1195 experienced ACS. Among the latter, 978 (70%) were diagnosed with NSTEMI, 225 (16%) with STEMI, and 194 with UA (14%). We observed 79.1% of STEMI patients receiving ICU care. 14.4% among NSTEMI patients, and 9.3% among UA patients. NSTEMI patients' mean hospital LOS was 3.7 days. This was shorter than that of non-ACS patients 4.75 days and UA patients 2.99. In-hospital mortality for NSTEMI was 1.6%, compared to, 4.4% for those with STEMI patients and 0% for UA. There are recommendations for risk stratification among NSTEMI patients to evaluate risk for major adverse cardiac events (MACE) that can be used in the ED to guide admission decisions and use of ICU care, thus optimizing care for a majority of ACS patients.

Performance of the European Society of Cardiology 0/1-Hour Algorithm With High-Sensitivity Cardiac Troponin T Among Patients With Known Coronary Artery Disease

Importance

The European Society of Cardiology (ESC) 0/1-hour algorithm is a validated high-sensitivity cardiac troponin (hs-cTn) protocol for emergency department patients with possible acute coronary syndrome. However, limited data exist regarding its performance in patients with known coronary artery disease (CAD; prior myocardial infarction [MI], coronary revascularization, or ≥70% coronary stenosis).

Objective

To evaluate and compare the diagnostic performance of the ESC 0/1-hour algorithm for 30-day cardiac death or MI among patients with and without known CAD and determine if the algorithm could achieve the negative predictive value rule-out threshold of 99% or higher.

Design, Setting, and Participants

This was a preplanned subgroup analysis of the STOP-CP prospective multisite cohort study, which was conducted from January 25, 2017, through September 6, 2018, at 8 emergency departments in the US. Patients 21 years or older with symptoms suggestive of acute coronary syndrome without ST-segment elevation on initial electrocardiogram were included. Analysis took place between February and December 2022.

Interventions/Exposures

Participants with 0- and 1-hour high-sensitivity cardiac troponin T (hs-cTnT) measures were stratified into rule-out, observation, and rule-in zones using the ESC 0/1-hour hs-cTnT algorithm.

Main Outcomes and Measures

Cardiac death or MI at 30 days determined by expert adjudicators.

Results

During the study period, 1430 patients were accrued. In the cohort, 775 individuals (54.2%) were male, 826 (57.8%) were White, and the mean (SD) age was 57.6 (12.8) years. At 30 days, cardiac death or MI occurred in 183 participants (12.8%). Known CAD was present in 449 (31.4%). Among patients with known CAD, the ESC 0/1-hour algorithm classified 178 of 449 (39.6%) into the rule-out zone compared with 648 of 981 (66.1%) without CAD (P < .001). Among rule-out zone patients, 30-day cardiac death or MI occurred in 6 of 178 patients (3.4%) with known CAD and 7 of 648 (1.1%) without CAD (P < .001). The negative predictive value for 30-day cardiac death or MI was 96.6% (95% CI, 92.8-98.8) among patients with known CAD and 98.9% (95% CI, 97.8-99.6) in patients without known CAD (P = .04).

Conclusions and Relevance

Among patients with known CAD, the ESC 0/1-hour hs-cTnT algorithm was unable to safely exclude 30-day cardiac death or MI. This suggests that clinicians should be cautious if using the algorithm in patients with known CAD. The negative predictive value was significantly higher in patients without a history of CAD but remained less than 99%.

Outpatient Myocardial Perfusion Imaging Scan for a Low-Risk Chest Pain Cohort From the Emergency Department: A Retrospective Analysis

Chest pain accounts for a significant attendances at emergency departments (ED). We examined the utility of early stress myocardial perfusion imaging (SMPI) for stratification of low-risk patients post-ED discharge. A retrospective audit was conducted of patients with chest pain and normal troponin-T (<30Ng/L), who were discharged with outpatient SMPI (median = 3 days post-ED discharge) between January 2018 to January 2020. 880 patients were included and followed up for 12 months. Outcomes measured were: 1) Cardiac events (CE) within 1 year of visit or 2) Significant coronary artery disease (CAD) - coronary angiography demonstrating ≥70% stenosis of epicardial vessels or coronary revascularization procedures performed. In the SMPI negative group, 2 of 802 patients (0.25%) had significant CEs and 11 patients (1.37%) were diagnosed with significant CAD. Of the 78 SMPI positive patients, 1 (1.28%) had a significant CE, while 24 had significant CAD. SMPI had a sensitivity of 65.8%, specificity of 93.7%, positive predictive value of 32.1% and a negative predictive value of 98.4% for predicting adverse CE. Early SMPI post-ED discharge demonstrated high negative predictive value in predicting CEs or significant CAD diagnosis at up to 1 year, suggesting that low-risk patients discharge from ED with early outpatient SMPI is a safe management option.

Rule-out of non-ST-segment elevation acute coronary syndrome by a single, pre-hospital troponin measurement: a randomized trial

AIMS

Patients with suspected non-ST-segment elevation acute coronary syndrome (NSTE-ACS) are routinely transferred to the emergency department (ED). A clinical risk score with point-of-care (POC) troponin measurement might enable ambulance paramedics to identify low-risk patients in whom ED evaluation is unnecessary. The aim was to assess safety and healthcare costs of a pre-hospital rule-out strategy using a POC troponin measurement in low-risk suspected NSTE-ACS patients.

METHODS AND RESULTS

This investigator-initiated, randomized clinical trial was conducted in five ambulance regions in the Netherlands. Suspected NSTE-ACS patients with HEAR (History, ECG, Age, Risk factors) score ≤3 were randomized to pre-hospital rule-out with POC troponin measurement or direct transfer to the ED. The sample size calculation was based on the primary outcome of 30-day healthcare costs. Secondary outcome was safety, defined as 30-day major adverse cardiac events (MACE), consisting of ACS, unplanned revascularization or all-cause death. : A total of 863 participants were randomized. Healthcare costs were significantly lower in the pre-hospital strategy (€1349 ± €2051 vs. €1960 ± €1808) with a mean difference of €611 [95% confidence interval (CI): 353-869; P < 0.001]. In the total population, MACE were comparable between groups [3.9% (17/434) in pre-hospital strategy vs. 3.7% (16/429) in ED strategy; P = 0.89]. In the ruled-out ACS population, MACE were very low [0.5% (2/419) vs. 1.0% (4/417)], with a risk difference of -0.5% (95% CI -1.6%-0.7%; P = 0.41) in favour of the pre-hospital strategy.

CONCLUSION

Pre-hospital rule-out of ACS with a POC troponin measurement in low-risk patients significantly reduces healthcare costs while incidence of MACE was low in both strategies.

TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT05466591 and International Clinical Trials Registry Platform id NTR 7346.

Prediction of significant coronary artery disease in acute chest pain without infarction in emergency department: MAPAC Cardio-PreTest model

Acute nontraumatic chest pain is a frequent reaso n for consultation in emergency departments and represents a diagnostic challenge. The objective is to estimate the risk of significant coronary artery disease (CAD) in patients with cardiogenic acute chest pain for whom the diagnosis of infarction was ruled out in the emergency department with a nondiagnostic ECG and negative high-sensitivity troponins. We prospectively recruited 1625 patients from emergency departments of seven Spanish hospitals. The outcome was presence of significant CAD determined by presence of ischaemia in functional tests or more than 70% stenosis in imaging tests. In this study, we developed a predictive model and evaluated its performance and clinical utility. The prevalence of significant CAD was 14% [227/1625; 95% confidence interval (CI), 12-16]. MAPAC Cardio-PreTest model included seven predictors: age, sex, smoking, history of hypertension, family history of CAD, history of hyperuricaemia, and type of chest pain. The optimism-adjusted model discrimination was C-statistic 0.654 (95% CI, 0.618-0.693). Calibration plot showed good agreement between the predicted and observed risks, and calibration slope was 0.880 (95% CI, 0.731-1.108) and calibration-in-the-large -0.001 (95% CI, -0.141 to 0.132). The model increased net benefit and improved risk classification over the recommended approach by the European Society of Cardiology [Net Reclassification Index (NRI) of events = 5.3%, NRI of nonevents = 7.0%]. MAPAC Cardio-PreTest model is an online prediction tool to estimate the individualised probability of significant CAD in patients with acute chest pain without a diagnosis of infarction in emergency department. The model was more useful than the current alternatives in helping patients and clinicians make individually tailored choices about the intensity of monitoring or additional coronary tests.

Derivation and validation of a high sensitivity troponin-T HEART pathway

BACKGROUND

The HEART Pathway is widely used for chest pain risk stratification but has yet to be optimized for high sensitivity troponin T (hs-cTnT) assays.

METHODS

We conducted a secondary analysis of STOP-CP, a prospective cohort study enrolling adult ED patients with symptoms suggestive of acute coronary syndrome at 8 sites in the United States (US). Patients had a 0- and 1-hour hs-cTnT measured and a HEAR score completed. A derivation set consisting of 729 randomly selected participants was used to derive a hs-cTnT HEART Pathway with rule-out, observation, and rule-in groups for 30-day cardiac death or myocardial infarction (MI). Optimal baseline and 1-hour troponin cutoffs were selected using generalized cross validation to achieve a negative predictive value (NPV) >99% for rule out and positive predictive value (PPV) >60% or maximum Youden index for rule-in. Optimal 0-1-hour delta values were derived using generalized cross validation to maximize the NPV for the rule-out group and PPV for the rule-in group. The hs-cTnT HEART Pathway performance was validated in the remaining cohort (n = 723).

RESULTS

Among the 1452 patients, 30-day cardiac death or MI occurred in 12.7% (184/1452). Within the derivation cohort the optimal hs-cTnT HEART Pathway classified 36.5% (266/729) into the rule-out group, yielding a NPV of 99.2% (95% CI: 98.2-100) for 30-day cardiac death or MI. The rule-in group included 15.4% (112/729) with a PPV of 55.4% (95% CI: 46.2-64.6). In the validation cohort, the hs-cTnT HEART Pathway ruled-out 37.6% (272/723), of which 2 had 30-day cardiac death or MI, yielding a NPV of 99.3% (95% CI: 98.3-100). The rule-in group included 14.5% (105/723), yielding a PPV of 57.1% (95% CI: 47.7-66.6).

CONCLUSIONS

A novel hs-cTnT HEART Pathway with serial 0- and 1-hour hs-cTnT measures has high NPV and moderate PPV for 30-day cardiac death or MI.

Rural and socioeconomic differences in the effectiveness of the HEART Pathway accelerated diagnostic protocol

BACKGROUND

The HEART Pathway is a validated accelerated diagnostic protocol (ADP) for patients with possible acute coronary syndrome (ACS). This study aimed to compare the safety and effectiveness of the HEART Pathway based on patient rurality (rural vs. urban) or socioeconomic status (SES).

METHODS

We performed a preplanned subgroup analysis of the HEART Pathway Implementation Study. The primary outcomes were death or myocardial infarction (MI) and hospitalization at 30 days. Proportions were compared by SES and rurality with Fisher's exact tests. Logistic regression evaluated for interactions of ADP implementation with SES or rurality and changes in outcomes within subgroups.

RESULTS

Among 7245 patients with rurality and SES data, 39.9% (2887/7245) were rural and 22.2% were low SES (1607/7245). The HEART Pathway identified patients as low risk in 32.2% (818/2540) of urban versus 28.1% (425/1512) of rural patients (p = 0.007) and 34.0% (311/915) of low SES versus 29.7% (932/3137) high SES patients (p = 0.02). Among low-risk patients, 30-day death or MI occurred in 0.6% (5/818) of urban versus 0.2% (1/425) rural (p = 0.67) and 0.6% (2/311) with low SES versus 0.4% (4/932) high SES (p = 0.64). Following implementation, 30-day hospitalization was reduced by 7.7% in urban patients (adjusted odds ratio [aOR] 0.76, 95% confidence interval [CI] 0.66-0.87), 10.6% in low SES patients (aOR 0.68, 95% CI 0.54-0.86), and 4.5% in high SES patients (aOR 0.83, 95% CI 0.73-0.94). However, rural patients had a nonsignificant 3.3% reduction in hospitalizations.

CONCLUSIONS

HEART Pathway implementation decreased 30-day hospitalizations regardless of SES and for urban patients but not rural patients. The 30-day death or MI rate was similar among low-risk patients.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prehospital Comparison of the HEAR and HE-MACS Scores for 30-Day Adverse Cardiac Events

OBJECTIVE

The History, Electrocardiogram (ECG), Age, and Risk factor (HEAR) and History and ECG-only Manchester Acute Coronary Syndromes (HE-MACS) risk scores can risk stratify chest pain patients without troponin measures. The objective of this study was to determine if either risk score could achieve the ≥99% negative predictive value (NPV) required to rule out major adverse cardiovascular events (MACE; a composite of all-cause death, myocardial infarction, or coronary revascularization) at 30 days or the ≥50% positive predictive value (PPV) indicative of a patient possibly needing interventional cardiology.

METHODS

We performed a pre-planned secondary analysis of the prospective multisite PARAHEART (n = 462, 12/2016-1/2018) and RESCUE (n = 767, 4/2018-1/2019) trials, which accrued adults ≥21 years old with acute non-traumatic chest pain transported by emergency medical services (EMS). Paramedics prospectively completed risk assessment forms. Very low risk was defined by a HEAR score of 0-1 or HE-MACS probability <4%. The primary outcome was 30-day MACE, which was determined by adjudication (PARAHEART) or electronic record review (RESCUE). NPV and PPV with exact 95% confidence intervals (95%CI) for 30-day MACE were calculated for each risk score and compared using McNemar's tests.

RESULTS

Among the PARAHEART and RESCUE cohorts, 30-day MACE occurred in 18.8% (87/462) and 6.9% (53/767) of patients, respectively. In PARAHEART, 7.8% (36/462) were very low risk by HEAR score vs. 7.8% (36/462) by HE-MACS (p = 1.0). The HEAR score had a NPV of 97.2% (95%CI 91.9-100.0) vs. 91.7% (95%CI 82.6-100.0) for HE-MACS (p = 0.15). The HEAR and HE-MACS PPVs were similar [46.4% (95%CI 28.0-64.9) vs. 33.3% (95%CI 13.2-53.5) (p = 0.26)]. In RESCUE, the HEAR score identified 14.2% (109/767) as low risk compared to 8.3% (64/767) by HE-MACS (p < 0.001). In this cohort, the HEAR and HE-MACS scores had similar NPVs [98.2% (95%CI 95.7-100.0) vs. 98.4% (95%CI 95.4-100.0) (p = 0.89)] and PPVs [16.2% (95%CI 6.2-32.0) vs. 22.6% (95%CI 12.3-36.2) (p = 0.41)].

CONCLUSIONS

In two prehospital chest pain cohorts, neither the HEAR score nor HE-MACS achieved sufficient NPV or PPV to rule out or rule in 30-day MACE.

Risk stratification of patients who present with chest pain and have normal troponins using a machine learning model

BACKGROUND

Risk stratification tools exist for patients presenting with chest pain to the emergency room and have achieved the recommended negative predictive value (NPV) of 99%. However, due to low positive predictive value (PPV), current stratification tools result in unwarranted investigations such as serial laboratory tests and cardiac stress tests (CSTs).

AIM

To create a machine learning model (MLM) for risk stratification of chest pain with a better PPV.

METHODS

This retrospective cohort study used de-identified hospital data from January 2016 until November 2021. Inclusion criteria were patients aged > 21 years who presented to the ER, had at least two serum troponins measured, were subsequently admitted to the hospital, and had a CST within 4 d of presentation. Exclusion criteria were elevated troponin value (> 0.05 ng/mL) and missing values for body mass index. The primary outcome was abnormal CST. Demographics, coronary artery disease (CAD) history, hypertension, hyperlipidemia, diabetes mellitus, chronic kidney disease, obesity, and smoking were evaluated as potential risk factors for abnormal CST. Patients were also categorized into a high-risk group (CAD history or more than two risk factors) and a low-risk group (all other patients) for comparison. Bivariate analysis was performed using a χ² test or Fisher’s exact test. Age was compared by t test. Binomial regression (BR), random forest, and XGBoost MLMs were used for prediction. Bootstrapping was used for the internal validation of prediction models. BR was also used for inference. Alpha criterion was set at 0.05 for all statistical tests. R software was used for statistical analysis.

RESULTS

The final cohort of the study included 2328 patients, of which 245 (10.52%) patients had abnormal CST. When adjusted for covariates in the BR model, male sex [risk ratio (RR) = 1.52, 95% confidence interval (CI): 1.2-1.94, P < 0.001)], CAD history (RR = 4.46, 95%CI: 3.08-6.72, P < 0.001), and hyperlipidemia (RR = 3.87, 95%CI: 2.12-8.12, P < 0.001) remained statistically significant. Incidence of abnormal CST was 12.2% in the high-risk group and 2.3% in the low-risk group (RR = 5.31, 95%CI: 2.75-10.24, P < 0.001). The XGBoost model had the best PPV of 24.33%, with an NPV of 91.34% for abnormal CST.

CONCLUSION

The XGBoost MLM achieved a PPV of 24.33% for an abnormal CST, which is better than current stratification tools (13.00%-17.50%). This highlights the beneficial potential of MLMs in clinical decision-making.

Monocyte chemoattractant protein-1 is not predictive of cardiac events in patients with non-low-risk chest pain

BACKGROUND

Prior studies suggest monocyte chemoattractant protein-1 (MCP-1) may be useful for risk stratifying ED patients with chest pain. We hypothesise that MCP-1 will be predictive of 90-day major adverse cardiovascular events (MACEs) in non-low-risk patients.

METHODS

A case-control study was nested within a prospective multicentre cohort (STOP-CP), which enrolled adult patients being evaluated for acute coronary syndrome at eight US EDs from 25 January 2017 to 06 September 2018. Patients with a History, ECG, Age, and Risk factor score (HEAR score) ≥4 or coronary artery disease (CAD), a non-ischaemic ECG, and non-elevated contemporary troponins at 0 and 3 hours were included. Cases were patients with 90-day MACE (all-cause death, myocardial infarction or revascularisation). Controls were patients without MACE selected with frequency matching using age, sex, race, and HEAR score or the presence of CAD. Serum MCP-1 was measured. Sensitivity and specificity were determined for cut-off points of 194 pg/mL, 200 pg/mL, 238 pg/mL and 281 pg/mL. Logistic regression adjusting for age, sex, race, and HEAR score/presence of CAD was used to determine the association between MCP-1 and 90-day MACE. A separate logistic model also included high-sensitivity troponin (hs-cTnT).

RESULTS

Among 40 cases and 179 controls, there was no difference in age (p=0.90), sex (p=1.00), race (p=0.85), or HEAR score/presence of CAD (p=0.89). MCP-1 was similar in cases (median 191.9 pg/mL, IQR: 161.8-260.1) and controls (median 196.6 pg/mL, IQR: 163.0-261.1) (p=0.48). At a cut-off point of 194 pg/mL, MCP-1 was 50.0% (95% CI 33.8% to 66.2%) sensitive and 46.9% (95% CI 39.4% to 54.5%) specific for 90-day MACE. After adjusting for covariates, MCP-1 was not associated with 90-day MACE at any cut-off point (at 194 pg/mL, OR 0.88 (95% CI 0.43 to 1.79)). When including hs-cTnT in the model, MCP-1 was not associated with 90-day MACE at any cut-off point (at 194 pg/mL, OR 0.85 (95% CI 0.42 to 1.73)).

CONCLUSION

MCP-1 is not predictive of 90-day MACE in patients with non-low-risk chest pain.

Transfer learning enables prediction of myocardial injury from continuous single-lead electrocardiography

OBJECTIVE

Chest pain is common, and current risk-stratification methods, requiring 12-lead electrocardiograms (ECGs) and serial biomarker assays, are static and restricted to highly resourced settings. Our objective was to predict myocardial injury using continuous single-lead ECG waveforms similar to those obtained from wearable devices and to evaluate the potential of transfer learning from labeled 12-lead ECGs to improve these predictions.

METHODS

We studied 10 874 Emergency Department (ED) patients who received continuous ECG monitoring and troponin testing from 2020 to 2021. We defined myocardial injury as newly elevated troponin in patients with chest pain or shortness of breath. We developed deep learning models of myocardial injury using continuous lead II ECG from bedside monitors as well as conventional 12-lead ECGs from triage. We pretrained single-lead models on a pre-existing corpus of labeled 12-lead ECGs. We compared model predictions to those of ED physicians.

RESULTS

A transfer learning strategy, whereby models for continuous single-lead ECGs were first pretrained on 12-lead ECGs from a separate cohort, predicted myocardial injury as accurately as models using patients' own 12-lead ECGs: area under the receiver operating characteristic curve 0.760 (95% confidence interval [CI], 0.721-0.799) and area under the precision-recall curve 0.321 (95% CI, 0.251-0.397). Models demonstrated a high negative predictive value for myocardial injury among patients with chest pain or shortness of breath, exceeding the predictive performance of ED physicians, while attending to known stigmata of myocardial injury.

CONCLUSIONS

Deep learning models pretrained on labeled 12-lead ECGs can predict myocardial injury from noisy, continuous monitor data early in a patient's presentation. The utility of continuous single-lead ECG in the risk stratification of chest pain has implications for wearable devices and preclinical settings, where external validation of the approach is needed.

Early computed tomography coronary angiography in adults presenting with suspected acute coronary syndrome: the RAPID-CTCA RCT

BACKGROUND

Acute coronary syndrome is a common medical emergency. The optimal strategy to investigate patients who are at intermediate risk of acute coronary syndrome has not been fully determined.

OBJECTIVE

To investigate the role of early computed tomography coronary angiography in the investigation and treatment of adults presenting with suspected acute coronary syndrome.

DESIGN

A prospective, multicentre, open, parallel-group randomised controlled trial with blinded end-point adjudication.

SETTING

Thirty-seven hospitals in the UK.

PARTICIPANTS

Adults (aged ≥ 18 years) presenting to the emergency department, acute medicine services or cardiology department with suspected or provisionally diagnosed acute coronary syndrome and at least one of the following: (1) a prior history of coronary artery disease, (2) a cardiac troponin level > 99th centile and (3) an abnormal 12-lead electrocardiogram.

INTERVENTIONS

Early computed tomography coronary angiography in addition to standard care was compared with standard care alone. Participants were followed up for 1 year.

MAIN OUTCOME MEASURE

One-year all-cause death or subsequent type 1 (spontaneous) or type 4b (stent thrombosis) myocardial infarction, measured as the time to such event adjudicated by two cardiologists blinded to the computerised tomography coronary angiography ( CTCA ) arm. Cost-effectiveness was estimated as the lifetime incremental cost per quality-adjusted life-year gained.

RESULTS

Between 23 March 2015 and 27 June 2019, 1748 participants [mean age 62 years (standard deviation 13 years), 64% male, mean Global Registry Of Acute Coronary Events score 115 (standard deviation 35)] were randomised to receive early computed tomography coronary angiography (n = 877) or standard care alone (n = 871). The primary end point occurred in 51 (5.8%) participants randomised to receive computed tomography coronary angiography and 53 (6.1%) participants randomised to receive standard care (adjusted hazard ratio 0.91, 95% confidence interval 0.62 to 1.35; p = 0.65). Computed tomography coronary angiography was associated with a reduced use of invasive coronary angiography (adjusted hazard ratio 0.81, 95% confidence interval 0.72 to 0.92; p = 0.001) but no change in coronary revascularisation (adjusted hazard ratio 1.03, 95% confidence interval 0.87 to 1.21; p = 0.76), acute coronary syndrome therapies (adjusted odds ratio 1.06, 95% confidence interval 0.85 to 1.32; p = 0.63) or preventative therapies on discharge (adjusted odds ratio 1.07, 95% confidence interval 0.87 to 1.32; p = 0.52). Early computed tomography coronary angiography was associated with longer hospitalisations (median increase 0.21 days, 95% confidence interval 0.05 to 0.40 days) and higher mean total health-care costs over 1 year (£561 more per patient) than standard care.

LIMITATIONS

The principal limitation of the trial was the slower than anticipated recruitment, leading to a revised sample size, and the requirement to compromise and accept a larger relative effect size estimate for the trial intervention.

FUTURE WORK

The potential role of computed tomography coronary angiography in selected patients with a low probability of obstructive coronary artery disease (intermediate or mildly elevated level of troponin) or who have limited access to invasive cardiac catheterisation facilities needs further prospective evaluation.

CONCLUSIONS

In patients with suspected or provisionally diagnosed acute coronary syndrome, computed tomography coronary angiography did not alter overall coronary therapeutic interventions or 1-year clinical outcomes, but it did increase the length of hospital stay and health-care costs. These findings do not support the routine use of early computed tomography coronary angiography in intermediate-risk patients with acute chest pain.

TRIAL REGISTRATION

This trial is registered as ISRCTN19102565 and Clinical Trials NCT02284191.

FUNDING

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 37. See the NIHR Journals Library website for further project information.

Age differences in the safety and effectiveness of the HEART Pathway accelerated diagnostic protocol for acute chest pain

BACKGROUND

The HEART Pathway is a validated protocol for risk stratifying emergency department (ED) patients with possible acute coronary syndrome (ACS). Its performance in different age groups is unknown. The objective of this study is to evaluate its safety and effectiveness among older adults.

METHODS

A pre-planned subgroup analysis of the HEART Pathway implementation study was conducted. This prospective interrupted time series accrued adult ED patients with possible ACS who were without ST-elevation across three US sites from 11/2013-01/2016. After implementation, providers prospectively used the HEART Pathway to stratify patients as low-risk or non-low-risk. Patients were classified as older adults (≥65 years), middle-aged (46-64 years), and young (21-45 years). Primary safety and effectiveness outcomes were 30-day death or MI and hospitalization at 30 days, determined from health records, insurance claims, and death index data. Fisher's exact test compared low-risk proportions between groups. Sensitivity for 30-day death or MI and adjusted odds ratios (aORs) for hospitalization and objective cardiac testing were calculated.

RESULTS

The HEART Pathway implementation study accrued 8474 patients, of which 26.9% (2281/8474) were older adults, 45.5% (3862/8474) middle-aged, and 27.5% (2331/8474) were young. The HEART Pathway identified 7.4% (97/1303) of older adults, 32.0% (683/2131) of middle-aged, and 51.4% (681/1326) of young patients as low-risk (p < 0.001). The HEART Pathway was 98.8% (95% CI 97.1-100) sensitive for 30-day death or MI among older adults. Following implementation, the rate of 30-day hospitalization was similar among older adults (aOR 1.25, 95% CI 1.00-1.55) and cardiac testing increased (aOR 1.25, 95% CI 1.04-1.51).

CONCLUSION

The HEART Pathway identified fewer older adults as low-risk and did not decrease hospitalizations in this age group.

Major adverse cardiac event rates in moderate-risk patients: Does prior coronary disease matter?

BACKGROUND

Despite negative troponins and nonischemic electrocardiograms (ECGs), patients at moderate risk for acute coronary syndrome (ACS) are frequently admitted. The objective of this study was to describe the major adverse cardiac event (MACE) rate in moderate-risk patients and how it differs based on history of coronary artery disease (CAD).

METHODS

A secondary analysis of the HEART Pathway implementation study was conducted. This prospective interrupted time-series study accrued adults with possible ACS from three sites (November 2013-January 2016). This analysis excluded low-risk patients determined by emergency providers' HEART Pathway assessments. Non-low-risk patients were further classified as high risk, based on elevated troponin measures or ischemic ECG findings or as moderate risk, based on HEAR score ≥ 4, negative troponin measures, and a nonischemic ECG. Moderate-risk patients were then stratified by the presence or absence of prior CAD (MI, revascularization, or ≥70% coronary stenosis). MACE (death, myocardial infarction, or revascularization) at 30 days was determined from health records, insurance claims, and death index data. MACE rates were compared among groups using a chi-square test and likelihood ratios (LRs) were calculated.

RESULTS

Among 4,550 patients with HEART Pathway assessments, 24.8% (1,130/4,550) were high risk and 37.7% (1715/4550) were moderate risk. MACE at 30 days occurred in 3.1% (53/1,715; 95% confidence interval [CI] = 2.3% to 4.0%) of moderate-risk patients. Among moderate-risk patients, MACE occurred in 7.1% (36/508, 95% CI = 5.1% to 9.8%) of patients with known CAD versus 1.4% (17/1,207, 95% CI = 0.9% to 2.3%) in patients without known prior CAD (p < 0.0001). The negative LR for 30-day MACE among moderate-risk patients without prior CAD was 0.08 (95% CI = 0.05 to 0.12).

CONCLUSION

MACE rates at 30 days were low among moderate-risk patients but were significantly higher among those with prior CAD.

Machine Learning to Assess for Acute Myocardial Infarction Within 30 Minutes

Variations in high-sensitivity cardiac troponin I by age and sex along with various sampling times can make the evaluation for acute myocardial infarction (AMI) challenging. Machine learning integrates these variables to allow a more accurate evaluation for possible AMI. The goal was to test the diagnostic and prognostic utility of a machine learning algorithm in the evaluation of possible AMI. We applied a machine learning algorithm (myocardial-ischemic-injury-index [MI3]) that incorporates age, sex, and high-sensitivity cardiac troponin I levels at time 0 and 30 minutes in 529 patients evaluated for possible AMI in a single urban emergency department. MI3 generates an index value from 0 to 100 reflecting the likelihood of AMI. Patients were followed at 30-45 days for major adverse cardiac events (MACEs). There were 42 (7.9%) patients that had an AMI. Patients were divided into 3 groups by the MI3 score: low-risk (≤ 3.13), intermediate-risk (> 3.13-51.0), and high-risk (> 51.0). The sensitivity for AMI was 100% with a MI3 value ≤ 3.13 and 353 (67%) ruled-out for AMI at 30 minutes. At 30-45 days, there were 2 (0.6%) MACEs (2 noncardiac deaths) in the low-risk group, in the intermediate-risk group 4 (3.0%) MACEs (3 AMIs, 1 cardiac death), and in the high-risk group 4 (9.1%) MACEs (4 AMIs, 2 cardiac deaths). The MI3 algorithm had 100% sensitivity for AMI at 30 minutes and identified a low-risk cohort who may be considered for early discharge.

Rapid Exclusion of Acute Myocardial Injury and Infarction with a Single High Sensitivity Cardiac Troponin T in the Emergency Department: a Multicenter United States Evaluation

BACKGROUND

There are good data to support using a single high-sensitivity cardiac troponin T (hs-cTnT) below the limit of detection (LoD) of 5 ng/L to exclude acute myocardial infarction. Per the United States (US) Food and Drug Administration (FDA), hs-cTnT can only report to the limit of quantitation (LoQ) of 6 ng/L, a threshold for which there is limited data. Our goal was to determine whether a single hs-cTnT below the LoQ of 6 ng/L is a safe strategy to identify patients at low-risk for acute myocardial injury and infarction.

METHODS

The efficacy (proportion identified as low-risk based on baseline hs-cTnT<6 ng/L) of identifying low-risk patients was examined in a multicenter (n=22 sites) US cohort study of emergency department patients undergoing at least one hs-cTnT (CV Data Mart Biomarker cohort). We then determined the performance of a single hs-cTnT<6 ng/L (biomarker alone) to exclude acute myocardial injury (subsequent hs-cTnT >99^th percentile in those with an initial hs-cTnT<6 ng/L). The clinically intended rule-out strategy combining a nonischemic electrocardiogram with a baseline hs-cTnT<6 ng/L was subsequently tested in an adjudicated cohort in which the diagnostic performance for ruling-out acute myocardial infarction and safety (myocardial infarction or death at 30-days) were evaluated.

RESULTS

A total of 85,610 patients were evaluated in the CV Data Mart Biomarker cohort, amongst which 24,646 (29%) had a baseline hs-cTnT<6 ng/L. Women were more likely than men to have hs-cTnT<6 ng/L (38% vs. 20%, p<0.0001). Among 11,962 patients with baseline hs-cTnT<6 ng/L and serial measurements, only 1.2% developed acute myocardial injury, resulting in a negative predictive value of 98.8% (95% CI 98.6, 99.0) and sensitivity of 99.6% (95% CI 99.5, 99.6). In the adjudicated cohort, a nonischemic electrocardiogram with hs-cTnT<6 ng/L identified 33% of patients (610 of 1849) as low-risk and resulted in a negative predictive value and sensitivity of 100% and a 30-day rate of 0.2% for 30-day myocardial infarction or death.

CONCLUSIONS

A single hs-cTnT below the LoQ of 6 ng/L is a safe and rapid method to identify a substantial number of patients at very low risk for acute myocardial injury and infarction.

Sex Differences in Identifying Chest Pain as Being of Cardiac Origin Using the HEART Pathway in the Emergency Department

Objectives: The HEART Pathway is a diagnostic protocol designed to identify low-risk patients with chest pain who can be safely discharged from the emergency department (ED) without hospitalization. Studies have reported a negative bias in identifying myocardial ischemia in females versus males and a different clinical pattern of cardiac ischemia across genders. This study sought to determine if the HEART Pathway recommendations are affected by negative bias in females. Design: A retrospective cohort study was conducted in the ED of an academic tertiary medical center. Admission/discharge decisions made by physicians in male and female patients presenting with chest pain in 4/2014-7/2019 were compared with HEART Pathway protocol predictions. Probabilities were estimated with logistic regression analysis, and odds ratios and 95% confidence intervals were calculated. Results: The cohort included 772 patients, 485 male (63%) and 287 female (37%), of median age 54 years. On the basis of their presenting symptoms, 278 patients (36%) were admitted by the ED physician and 494 (64%) were discharged. Using the HEART Pathway protocol, 227 patients (29.4%) would be expected to be admitted and 545 (70.6%) discharged. The real-life admission rate was higher than possible with the HEART Protocol (p = 0.001). In a regression model, male sex was a significant factor favoring admission among the patients for whom the HEART Pathway predicted admission (p = 0.007). Conclusions: As the HEART Pathway is a validated risk-stratification tool, there is a high likelihood that serious coronary artery disease may be overlooked in women, even those who seek timely medical assistance.