Coronary CT angiography for acute chest pain

Performance of the EDACS-ADP incorporating highsensitivity troponin assay: Do components of major adverse cardiac events matter?

BACKGROUND

The accelerated diagnostic protocol (ADP) using the Emergency Department Assessment of Chest pain Score (EDACS-ADP), a tool to identify patients at low risk of a major adverse cardiac event (MACE) among patients presenting with chest pain to the emergency department, was developed using a contemporary troponin assay. This study was performed to validate and compare the performance of the EDACS-ADP incorporating high-sensitivity cardiac troponin I between patients who had a 30-day MACE with and without unstable angina (MACE I and II, respectively).

METHODS

A single-center prospective observational study of adult patients presenting with chest pain suggestive of acute coronary syndrome was performed. The performance of EDACS-ADP in predicting MACE was assessed by calculating the sensitivity and negative predictive value.

RESULTS

Of the 1,304 patients prospectively enrolled, 399 (30.6%; 95% confidence interval [95% CI]: 27.7%-33.8%) were considered low-risk using the EDACS-ADP. Among them, the rates of MACE I and II were 1.3% (5/399) and 1.0% (4/399), respectively. The EDACS-ADP showed sensitivities and negative predictive values of 98.8% (95% CI: 97.2%-99.6%) and 98.7% (95% CI: 97.0%-99.5%) for MACE I and 98.7% (95% CI: 96.8%-99.7%) and 99.0% (95% CI: 97.4%-99.6%) for MACE II, respectively.

CONCLUSION

EDACS-ADP could help identify patients as safe for early discharge. However, when unstable angina was added to the outcome, the 30-day MACE rate among the designated low-risk patients remained above the level acceptable for early discharge without further evaluation.

Epicardial adipose tissue and obstructive coronary artery disease in acute chest pain: the EPIC-ACS study

Aims

We tested the hypothesis that epicardial adipose tissue (EAT) quantification improves the prediction of the presence of obstructive coronary artery disease (CAD) in patients presenting with acute chest pain to the emergency department.

Methods and results

Within this prospective observational cohort study, we included 657 consecutive patients (mean age 58.06 ± 18.04 years, 53% male) presenting to the emergency department with acute chest pain suggestive of acute coronary syndrome between December 2018 and August 2020. Patients with ST-elevation myocardial infarction, haemodynamic instability, or known CAD were excluded. As part of the initial workup, we performed bedside echocardiography for quantification of EAT thickness by a dedicated study physician, blinded to all patient characteristics. Treating physicians remained unaware of the results of the EAT assessment. The primary endpoint was defined as the presence of obstructive CAD, as detected in subsequent invasive coronary angiography. Patients reaching the primary endpoint had significantly more EAT than patients without obstructive CAD (7.90 ± 2.56 mm vs. 3.96 ± 1.91 mm, P < 0.0001). In a multivariable regression analysis, a 1 mm increase in EAT thickness was associated with a nearby two-fold increased odds of the presence of obstructive CAD [1.87 (1.64-2.12), P < 0.0001]. Adding EAT to a multivariable model of the GRACE score, cardiac biomarkers and traditional risk factors significantly improved the area under the receiver operating characteristic curve (0.759-0.901, P < 0.0001).

Conclusion

Epicardial adipose tissue strongly and independently predicts the presence of obstructive CAD in patients presenting with acute chest pain to the emergency department. Our results suggest that the assessment of EAT may improve diagnostic algorithms of patients with acute chest pain.

Early computed tomography coronary angiography in patients with suspected acute coronary syndrome: randomised controlled trial

OBJECTIVES

To establish if the use of early computed tomography (CT) coronary angiography improves one year clinical outcomes in patients presenting to the emergency department with acute chest pain and at intermediate risk of acute coronary syndrome and subsequent clinical events.

DESIGN

Randomised controlled trial.

SETTING

37 hospitals in the UK.

PARTICIPANTS

Adults with suspected or a provisional diagnosis of acute coronary syndrome and one or more of previous coronary heart disease, raised levels of cardiac troponin, or abnormal electrocardiogram.

INTERVENTIONS

Early CT coronary angiography and standard of care compared with standard of care only.

MAIN OUTCOME MEASURES

Primary endpoint was all cause death or subsequent type 1 or 4b myocardial infarction at one year.

RESULTS

Between 23 March 2015 and 27 June 2019, 1748 participants (mean age 62 years (standard deviation 13), 64% men, mean global registry of acute coronary events (GRACE) score 115 (standard deviation 35)) were randomised to receive early CT coronary angiography (n=877) or standard of care only (n=871). Median time from randomisation to CT coronary angiography was 4.2 (interquartile range 1.6-21.6) hours. The primary endpoint occurred in 51 (5.8%) participants randomised to CT coronary angiography and 53 (6.1%) participants who received standard of care only (adjusted hazard ratio 0.91 (95% confidence interval 0.62 to 1.35), P=0.65). Invasive coronary angiography was performed in 474 (54.0%) participants randomised to CT coronary angiography and 530 (60.8%) participants who received standard of care only (adjusted hazard ratio 0.81 (0.72 to 0.92), P=0.001). There were no overall differences in coronary revascularisation, use of drug treatment for acute coronary syndrome, or subsequent preventive treatments between the two groups. Early CT coronary angiography was associated with a slightly longer time in hospital (median increase 0.21 (95% confidence interval 0.05 to 0.40) days from a median hospital stay of 2.0 to 2.2 days).

CONCLUSIONS

In intermediate risk patients with acute chest pain and suspected acute coronary syndrome, early CT coronary angiography did not alter overall coronary therapeutic interventions or one year clinical outcomes, but reduced rates of invasive angiography while modestly increasing length of hospital stay. These findings do not support the routine use of early CT coronary angiography in intermediate risk patients with acute chest pain and suspected acute coronary syndrome.

TRIAL REGISTRATION

ISRCTN19102565, NCT02284191.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

STUDY OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Usefulness of Predischarge Cardiac Testing in Low Risk Women and Men for Safe, Rapid Discharge from a Chest Pain Unit

Predischarge cardiac testing (PDT) in low-risk patients evaluated for acute coronary syndrome in a chest pain unit (CPU) remains a challenge. It is unclear whether PDT varies by gender. We analyzed consecutive low-risk women and men evaluated in our CPU over a 2-year period and compared the utilization of PDT (exercise treadmill test, myocardial stress perfusion scintigraphy, exercise stress echocardiography, invasive coronary angiography, or no test), and incidence of major adverse cardiac events (MACE) at 30 days and 6 months. The study group comprised 619 patients (54% women). A large proportion of both genders did not undergo PDT, although this finding was more frequent in women (50% women vs 40% men, p = 0.01). At 30 days, there were no MACE in either gender. After 6 months of follow-up, MACE remained very low in both women and men (2 [1%] vs 2 [1%]), and in patients who did and did not receive PDT (2 [1%] vs 2 [1%]). Mean length of stay in the CPU was 5.4 hours in patients without PDT and 9.8 hours in those with PDT (p <0.0001) without altering postdischarge MACE. When referred for PDT, women more often underwent myocardial stress perfusion scintigraphy than men (22% vs 14%, p = 0.005) and less often received exercise treadmill test (20% vs 39%, p <0.0001). Yield of abnormal PDT was low in both women and men although it was lower in women (1% vs 5%, p = 0.02). In conclusion, many low-risk women and men evaluated in a CPU for acute coronary syndrome can be safely and rapidly discharged without PDT and with low risk for MACE at 30 days and at 6 months. Exclusion of PDT was associated with significantly reduced length of stay while maintaining safety in terms of postdischarge MACE.

Incorporation of the HEART Score Into a Low-risk Chest Pain Pathway to Safely Decrease Admissions

Chest pain can be a challenging complaint to manage in the emergency department. A missed diagnosis can result in significant morbidity or mortality, whereas avoidable testing and hospitalizations can lead to increased health care costs, contribute to hospital crowding, and increase risks to patients. The HEART score is a validated decision aid to identify patients at low risk for acute coronary syndrome who can be safely discharged without admission or objective cardiac testing. In the largest and one of the longest studies to date (N = 31,060; 30 months), we included the HEART score into a larger, newly developed low-risk chest pain decision pathway, using a retrospective observational pre/post study design with the objective of safely lowering admissions. The modified HEART score calculation tool was incorporated in our electronic medical record. A significant increase in discharges of low-risk chest pain patients (relative increase of 21%; p < 0.0001) in the postimplementation period was observed with no significant difference in the rates of major adverse cardiac events between the pre and post periods. There was a decrease in the amount of return admissions for 30 days (4.65% fewer; p = 0.009) and 60 days (3.78% fewer; p = 0.020). No significant difference in length of stay was observed for patients who were ultimately discharged. A 64% decrease in monthly coronary computed tomography angiograms was observed in the post period (p < 0.0001). These findings support the growing consensus in the literature that the adoption of the HEART pathway or similar protocols in emergency departments, including at large and high-volume medical institutions, can substantially benefit patient care and reduce associated health care costs.

The HEART Pathway Randomized Controlled Trial One-year Outcomes

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Risk stratification and role for additional diagnostic testing in patients with acute chest pain and normal high-sensitivity cardiac troponin levels

Background

Normal high sensitivity cardiac troponin (hs-cTn) assays rule out acute myocardial infarction (AMI) with great accuracy, but additional non-invasive testing is frequently ordered. This observational study evaluates whether clinical characteristics can contribute to risk stratification and could guide referral for additional testing.

Methods

918 serial patients with acute chest pain and normal hs-cTnT levels were prospectively included. Major adverse cardiac events (MACE) and non-invasive test results were assessed during one-year follow-up. Patients were classified as low and high risk based on clinical characteristics.

Results

MACE occurred in 6.1% of patients and mainly comprised revascularizations (86%). A recent abnormal stress test, suspicious history, a positive family history and higher baseline hs-cTnT levels were independent predictors of MACE with odds ratios of 16.00 (95%CI:6.25–40.96), 16.43 (6.36–42.45), 2.33 (1.22–4.42) and 1.10 (1.01–1.21), respectively. Absence of both recent abnormal stress test and suspicious history identified 86% of patients. These patients were at very low risk for MACE (0.4% in 30-days and 2.3% in one-year). Despite this, the majority (287/345 = 83%) of additional tests were performed in low risk patients, with <10% abnormal test findings. The diagnostic yield was significantly higher in the remaining higher risk patients, 40% abnormal test findings and a positive predictive value of 70% for MACE. Similar results were observed in patients without known coronary artery disease.

Conclusions

Clinical characteristics can be used to identify low risk patients with acute chest pain and normal hs-cTnT levels. Current strategies in the emergency department result in numerous additional tests, which are mostly ordered in patients at very low risk and have a low diagnostic yield.

Utility of Physician Selection of Cardiac Tests in a Chest Pain Unit to Exclude Acute Coronary Syndrome Among Patients Without a History of Coronary Artery Disease

There are few data on the utility of physician selection of cardiac tests, including no-test, in a chest pain unit (CPU) to rule out acute coronary syndrome in low-risk patients without a history of coronary artery disease. We analyzed consecutive low-risk patients admitted to our CPU between 2012 and 2014 and determined the proportion of patients selected for testing, the type of initial cardiac test selected, and the incidence of major adverse cardiac events (MACEs) at 30 days and 6 months. The study group comprised 619 patients: mean age 57 years (27 to 92), 332 women (54%), and 360 (58%) with multiple cardiac risk factors. Cardiac testing included 283 no-test (46%); 179 exercise treadmill (29%); 113 myocardial perfusion stress scintigraphy (18%); <10% each for exercise stress echocardiography and coronary angiography. Testing was negative in 296 (88%), nondiagnostic in 30 (9%), and positive in 10 patients (3%). There were no MACEs at 30 days in any patients, and at 6 months, MACEs were 5 (1.1%). Length of stay was less in no-test than in tested patients (5.4 hours vs 9.8 hours, p <0.0001), and there was no difference in incidence of MACE at 6 months in no-test vs tested patients (2 MACEs vs 3 MACEs). Physician selection of cardiac tests, including no-test, promptly identified patients at low risk of acute coronary syndrome who could be safely and rapidly discharged from the CPU. Exclusion of cardiac testing shortened length of stay and was not associated with increase in MACE at 6 months.

Cardiac CT in the Emergency Department: Contrasting Evidence from Registries and Randomized Controlled Trials

PURPOSE OF REVIEW

To compare outcomes between registries and randomized controlled trials of coronary computed tomographic angiography (CCTA)-based versus standard of care approaches to the initial evaluation of patients with acute chest pain.

RECENT FINDINGS

Randomized trials have demonstrated CCTA to be a safe and efficient tool for triage of low- to intermediate-risk patients presenting to the emergency department with chest pain. Recent studies demonstrate heterogeneous result using different standard of care approaches for evaluation of hard endpoints in comparison with standard evaluation. Also, there has been continued concern for increase in subsequent testing after coronary CTA. Although CCTA improves detection of coronary artery disease, it is uncertain if it will bring improvement of long-term health outcomes at this point of time. Careful analysis of the previous results and further investigation will be required to validate evaluation of hard endpoints.

Noninvasive Cardiac Testing vs Clinical Evaluation Alone in Acute Chest Pain: A Secondary Analysis of the ROMICAT-II Randomized Clinical Trial

IMPORTANCE

The incremental benefit of noninvasive testing in addition to clinical evaluation (history, physical examination, an electrocardiogram [ECG], and biomarker assessment) vs clinical evaluation alone for patients who present to the emergency department (ED) with acute chest pain is unknown.

OBJECTIVE

To examine differences in outcomes with clinical evaluation and noninvasive testing (coronary computed tomographic angiography [CCTA] or stress testing) vs clinical evaluation alone.

DESIGN, SETTING, AND PARTICIPANTS

This study was a retrospective analysis of data from the randomized multicenter Rule Out Myocardial Ischemia/Infarction by Computer Assisted Tomography (ROMICAT-II) trial. Data for 1000 patients who presented with chest pain to the EDs at 9 hospitals in the United States were evaluated.

INTERVENTIONS

Clinical evaluation plus noninvasive testing (CCTA or stress test) vs clinical evaluation alone.

MAIN OUTCOMES AND MEASURES

Primary outcome was length of stay (LOS). Secondary outcomes included hospital admission, direct ED discharge, downstream testing, rates of invasive coronary angiography, revascularization, major adverse cardiac events (MACE), repeated ED visit or hospitalization for recurrent chest pain at 28 days, and cost. Safety end points were missed acute coronary syndrome (ACS) and cumulative radiation exposure during the index visit and follow-up period.

RESULTS

Of the 1000 patients randomized, 118 patients (12%) (mean [SD] age, 53.2 [7.8]; 49 [42%] were female) did not undergo noninvasive testing, whereas 882 (88%) (mean [SD] age, 54.4 [8.14] years; 419 [48%] were female) received CCTA or stress testing. There was no difference in baseline characteristics or clinical presentation between groups. Patients who underwent clinical evaluation alone experienced a shorter LOS (20.3 vs 27.9 hours; P < .001), lower rates of diagnostic testing (P < .001) and angiography (2% vs 11%; P < .001), lower median costs ($2261.50 vs $2584.30; P = .009), and less cumulative radiation exposure (0 vs 9.9 mSv; P < .001) during the 28-day study period. Lack of testing was associated with a lower rate of diagnosis of ACS (0% vs 9%; P < .001) and less coronary angiography and percutaneous coronary intervention (PCI) during the index visit (0% vs 10%; P < .001, and 0% vs 4%; P = .02, respectively). There was no difference in rates of PCI (2% vs 5%; P = .15), coronary artery bypass surgery (0% vs 1%; P = .61), return ED visits (5.8% vs 2.8%; P = .08), or MACE (2% vs 1%; P = .24) in the 28-day follow-up period.

CONCLUSIONS AND RELEVANCE

In patients presenting to the ED with acute chest pain, negative biomarkers, and a nonischemic ECG result, noninvasive testing with CCTA or stress testing leads to longer LOS, more downstream testing, more radiation exposure, and greater cost without an improvement in clinical outcomes.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01084239.

Implementation of a Risk Stratification and Management Pathway for Acute Chest Pain in the Emergency Department

OBJECTIVES

Chest pain is a common complaint in the emergency department, and a small but important minority represents an acute coronary syndrome (ACS). Variation in diagnostic workup, risk stratification, and management may result in underuse, misuse, and/or overuse of resources.

METHODS

From July to October 2014, we conducted a prospective cohort study in an academic medical center by implementing a Standardized Clinical Assessment and Management Plan (SCAMP) for chest pain based on the HEART score. In addition to capturing adherence to the SCAMP algorithm and reasons for any deviations, we measured troponin sample timing; rates of stress test utilization; length of stay (LOS); and 30-day rates of revascularization, ACS, and death.

RESULTS

We identified 239 patients during the enrollment period who were eligible to enter the SCAMP, of whom 97 patients were entered into the pathway. Patients were risk stratified into one of 3 risk tiers: high (n = 3), intermediate (n = 40), and low (n = 54). Among low-risk patients, recommendations for troponin testing were not followed in 56%, and 11% received stress tests contrary to the SCAMP recommendation. None of the low-risk patients had elevated troponin measurements, and none had an abnormal stress test. Mean LOS in low-risk patients managed with discordant plans was 22:26 h/min, compared with 9:13 h/min in concordant patients (P < 0.001). Mean LOS in intermediate-risk patients with stress testing was 25:53 h/min, compared with 7:55 h/min for those without (P < 0.001). At 30 days, 10% of intermediate-risk patients and 0% of low-risk patients experienced an ACS event (risk difference 10% [0.7%-19%]); none experienced revascularization or death. The most frequently cited reason for deviation from the SCAMP was lack of confidence in the tool.

CONCLUSIONS

Compliance with SCAMP recommendations for low- and intermediate-risk patients was poor, largely due to lack of confidence in the tool. However, in our study population, outcomes suggest that deviation from the SCAMP yielded no additional clinical benefit while significantly prolonging emergency department LOS.

Cardiovascular Testing and Clinical Outcomes in Emergency Department Patients With Chest Pain

IMPORTANCE

Noninvasive testing and coronary angiography are used to evaluate patients who present to the emergency department (ED) with chest pain, but their effects on outcomes are uncertain.

OBJECTIVE

To determine whether cardiovascular testing-noninvasive imaging or coronary angiography-is associated with changes in the rates of coronary revascularization or acute myocardial infarction (AMI) admission in patients who present to the ED with chest pain without initial findings of ischemia.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort analysis used weekday (Monday-Thursday) vs weekend (Friday-Sunday) presentation as an instrument to adjust for unobserved case-mix variation (selection bias) between 2011 and 2012. National claims data (Truven MarketScan) was used. The data included a total of 926 633 privately insured patients ages 18 to 64 years who presented to the ED with chest pain without initial diagnosis consistent with acute ischemia.

EXPOSURES

Noninvasive testing or coronary angiography within 2 days or 30 days of presentation.

MAIN OUTCOMES AND MEASURES

The primary end points were coronary revascularization (percutaneous coronary intervention or coronary artery bypass graft surgery) and AMI admission at 7, 30, 180, and 365 days. The secondary end points were coronary angiography and coronary artery bypass grafting in those who underwent angiography.

RESULTS

The patients were ages 18 to 64 years with an average age of 44.4 years. A total of 536 197 patients (57.9%) were women. Patients who received testing (224 973) had increased risk at baseline and had greater risk of AMI admission than those who did not receive testing (701 660) (0.35% vs 0.14% at 30 days). Weekday patients (571 988) had similar baseline comorbidities to weekend patients (354 645) but were more likely to receive testing. After risk factor adjustment, testing within 30 days was associated with a significant increase in coronary angiography (36.5 per 1000 patients tested; 95% CI, 21.0-52.0) and revascularization (22.8 per 1000 patients tested; 95% CI, 10.6-35.0) at 1 year but no significant change in AMI admissions (7.8 per 1000 patients tested; 95% CI, -1.4 to 17.0). Testing within 2 days was also associated with a significant increase in coronary revascularization but no difference in AMI admissions.

CONCLUSIONS AND RELEVANCE

Cardiac testing in patients with chest pain was associated with increased downstream testing and treatment without a reduction in AMI admissions, suggesting that routine testing may not be warranted. Further research into whether specific high-risk subgroups benefit from testing is needed.

A Multivariate Model for Prediction of Obstructive Coronary Disease in Patients with Acute Chest Pain: Development and Validation

Background

Currently, there is no validated multivariate model to predict probability of obstructive coronary disease in patients with acute chest pain.

Objective

To develop and validate a multivariate model to predict coronary artery disease (CAD) based on variables assessed at admission to the coronary care unit (CCU) due to acute chest pain.

Methods

A total of 470 patients were studied, 370 utilized as the derivation sample and the subsequent 100 patients as the validation sample. As the reference standard, angiography was required to rule in CAD (stenosis ≥ 70%), while either angiography or a negative noninvasive test could be used to rule it out. As predictors, 13 baseline variables related to medical history, 14 characteristics of chest discomfort, and eight variables from physical examination or laboratory tests were tested.

Results

The prevalence of CAD was 48%. By logistic regression, six variables remained independent predictors of CAD: age, male gender, relief with nitrate, signs of heart failure, positive electrocardiogram, and troponin. The area under the curve (AUC) of this final model was 0.80 (95% confidence interval [95%CI] = 0.75 - 0.84) in the derivation sample and 0.86 (95%CI = 0.79 - 0.93) in the validation sample. Hosmer-Lemeshow's test indicated good calibration in both samples (p = 0.98 and p = 0.23, respectively). Compared with a basic model containing electrocardiogram and troponin, the full model provided an AUC increment of 0.07 in both derivation (p = 0.0002) and validation (p = 0.039) samples. Integrated discrimination improvement was 0.09 in both derivation (p < 0.001) and validation (p < 0.0015) samples.

Conclusion

A multivariate model was derived and validated as an accurate tool for estimating the pretest probability of CAD in patients with acute chest pain.

Noninvasive Testing in Emergency Department Patients with Low-Risk Chest Pain: Does the Evidence Support Current Guidelines?

Patients who present to the emergency department with chest pain but no evidence of ischemia on the electrocardiogram and negative cardiac markers are at very low risk. The newest American Heart Association/American College of Cardiology guidelines give noninvasive cardiac testing a IIa recommendation in this patient population. Here, we will review the existing literature that was cited in the American Heart Association/American College of Cardiology document, as well as several large, contemporary, comparative observational studies which were not included to address the following question: Do the benefits of noninvasive cardiac testing in this patient population outweigh the risks?

Comparison of the Effectiveness of Stress Echocardiography Versus Myocardial Perfusion Imaging in Patients Presenting to the Emergency Department With Low-Risk Chest Pain

The aim of this study was to compare clinically relevant cardiovascular outcomes and downstream resource utilization associated with stress echocardiography (SE) and myocardial perfusion imaging (MPI) in emergency department patients with low-risk chest pain. This was a retrospective analysis of health insurance claims data for a national sample of privately insured patients over the period January 1 to December 31, 2011. Subjects were selected who presented to the emergency department with a primary or secondary diagnosis of chest pain and underwent either SE or MPI. The primary end points were the percentage of patients in each group who underwent downstream cardiac catheterization, revascularization, repeat noninvasive testing, return emergency department visit with chest pain, and hospitalization for myocardial infarction. The mean length of follow-up was 190 days in both groups. Overall, 48,202 patients or 24,101 propensity-matched pairs were included in the final analysis. Compared with SE, MPI was associated with significantly higher odds of subsequent cardiac catheterization (adjusted odds ratio [AOR] 2.15; 95% confidence interval [CI] 1.99 to 2.33) and revascularization procedures (AOR 1.58; 95% CI 1.36 to 1.85) and repeat emergency department visits (AOR 1.14; 95% CI 1.11 to 1.19). The odds of repeat testing and myocardial infarction did not differ between groups. The average cost of downstream care was significantly higher in the MPI group ($2,193.80 vs $1,631.10, p <0.0001). According to the a priori rules specified for this comparative analysis, SE is more effective than MPI for privately insured patients who present to the emergency department with chest pain. In conclusion, these findings demonstrate the importance of assessing diagnostic tests based on how they affect hard end points because identification of disease, in and of itself, may not confer any clinical advantage.

Best Clinical Practice: Current Controversies in Evaluation of Low-Risk Chest Pain-Part 1

BACKGROUND

Chest pain is a common presentation to the emergency department (ED), though the majority of patients are not diagnosed with acute coronary syndrome (ACS). Many patients are admitted to the hospital due to fear of ACS.

OBJECTIVE

Our aim was to investigate controversies in low-risk chest pain evaluation, including risk of missed ACS, stress test, and coronary computed tomography angiography (CCTA).

DISCUSSION

Chest pain accounts for 10 million ED visits in the United States annually. Many patients are at low risk for a major cardiac adverse event (MACE). With negative troponin and nonischemic electrocardiogram (ECG), the risk of MACE and myocardial infarction (MI) is < 1%. The American Heart Association recommends further evaluation in low- to intermediate-risk patients within 72 h. These modalities add little to further risk stratification. These evaluations do not appropriately risk stratify patients who are already at low risk, nor do they diagnose acute MI. CCTA is an anatomic evaluation of the coronary vasculature with literature support to decrease ED length of stay, though it is associated with downstream testing. Literature is controversial concerning further risk stratification in already low-risk patients.

CONCLUSIONS

With nonischemic ECG and negative cardiac biomarker, the risk of ACS approaches < 1%. Use of stress test and CCTA for risk stratification of low-risk chest pain patients is controversial. These tests may allow prognostication but do not predict ACS risk beyond ECG and troponin. CCTA may be useful for intermediate-risk patients, though further studies are required.

Performance of the EDACS-accelerated Diagnostic Pathway in a Cohort of US Patients with Acute Chest Pain

BACKGROUND

The Emergency Department Assessment of Chest pain Score-Accelerated Diagnostic Protocol (EDACS-ADP) is a decision aid designed to safely identify emergency department (ED) patients with chest pain for early discharge. Derivation and validation studies in Australasia have demonstrated high sensitivity (99%-100%) for major adverse cardiac events (MACE).

OBJECTIVES

To validate the EDACS-ADP in a cohort of US ED patients with symptoms suspicious for acute coronary syndrome (ACS).

METHODS

A secondary analysis of participants enrolled in the HEART Pathway Randomized Controlled Trial was conducted. This single-site trial enrolled 282 ED patients≥21 years old with symptoms concerning for ACS, inclusive of all cardiac risk levels. Each patient was classified as low risk or at risk by the EDACS-ADP based on EDACS, electrocardiogram, and serial troponins. Potential early discharge rate and sensitivity for MACE at 30 days, defined as cardiac death, myocardial infarction (MI), or coronary revascularization were calculated.

RESULTS

MACE occurred in 17/282 (6.0%) participants, including no deaths, 16/282 (5.6%) with MI, and 1/282 (0.4%) with coronary revascularization without MI. The EDACS-ADP identified 188/282 patients [66.7%, 95% confidence interval (CI): 60.8%-72.1%] as low risk. Of these, 2/188 (1.1%, 95% CI: 0.1%-3.9%) had MACE at 30 days. EDACS-ADP was 88.2% (95% CI: 63.6%-98.5%) sensitive for MACE, identifying 15/17 patients. Of the 2 patients identified as low risk with MACE, 1 had MI and 1 had coronary revascularization without MI.

CONCLUSIONS

Within a US cohort of ED patients with symptoms concerning for ACS, sensitivity for MACE was 88.2%. We are unable to validate the EDACS-ADP as sufficiently sensitive for clinical use.

Comparison of Rates of Coronary Angiography and Combined Testing Procedures in Patients Seen in the Emergency Room With Chest Pain (But No Objective Acute Coronary Syndrome Findings) Having Coronary Computed Tomography Versus Exercise Stress Testing

Coronary computed tomography angiography (CCTA) appears comparable to standard care, including exercise stress testing (EST), in diagnosing acute coronary syndrome in emergency department (ED) patients with chest pain but may increase downstream testing. The objective of this study was to investigate rates of post-CCTA versus post-EST testing for (1) invasive angiography and (2) all combined cardiac testing. This was a retrospective cohort study performed at 2 urban Canadian EDs involving patients aged up to 65 years with chest pain but no objective ACS findings that were evaluated with CCTA or EST at the physician's discretion. The primary outcome was the proportion of patients who had 30-day invasive angiography in each group; secondary outcomes included all subsequent 30-day cardiac testing, including nuclear medicine scanning. From July 1, 2012, to June 30, 2014, we collected 1,700 patients: 521 CCTA and 1,179 EST. Demographics and risk factors were similar in both cohorts. In the following 30 days, 30 CCTA (5.8%) and 297 EST (25.2%) patients underwent any type of additional cardiac testing (difference 19.4%, 95% CI 16.0 to 22.6), whereas 12 CCTA (2.3%) and 20 EST patients (1.7%) underwent angiography (difference 0.6%, 95% CI -0.8% to 2.6%). No patients in either group died or had a myocardial infarction within 30 days. For ED patients with chest pain who underwent brief observation, CCTA and EST had similar 30-day angiography rates, but CCTA patients underwent significantly less overall cardiac investigations.

Acute chest pain in the high-sensitivity cardiac troponin era: A changing role for noninvasive imaging?

Management of patients with acute chest pain remains challenging. Cardiac biomarker testing reduces the likelihood of erroneously discharging patients with acute myocardial infarction (AMI). Despite normal contemporary troponins, physicians have still been reluctant to discharge patients without additional testing. Nowadays, the extremely high negative predictive value of current high-sensitivity cardiac troponin (hs-cTn) assays challenges this need. However, the decreased specificity of hs-cTn assays to diagnose AMI poses a new problem as noncoronary diseases (eg, pulmonary embolism, myocarditis, cardiomyopathies, hypertension, renal failure, etc) may also cause elevated hs-cTn levels. Subjecting patients with noncoronary diseases to unnecessary pharmacological therapy or invasive procedures must be prevented. Attempts to improve the positive predictive value to diagnose AMI by defining higher initial cutoff values or dynamic changes over time inherently lower the sensitivity of troponin assays. In this review, we anticipate a potential changing role of noninvasive imaging from ruling out myocardial disease when troponin values are normal toward characterizing myocardial disease when hs-cTn values are (mildly) abnormal.

Association of Early Stress Testing with Outcomes for Emergency Department Evaluation of Suspected Acute Coronary Syndrome

BACKGROUND

Professional society guidelines suggest early stress testing (within 72 hours) after an emergency department (ED) evaluation for suspected acute coronary syndrome (ACS). However, there is increasing concern that current practice results in over-testing without evidence of benefit. We test the hypothesis that early stress testing improves outcomes.

METHODS

We analyzed prospectively collected data from 9 EDs on patients with suspected ACS, 1999-2001. We excluded patients with an ED diagnosis of ACS. The primary outcome was 30-day major adverse cardiac events (MACEs), including all-cause death, acute myocardial infarction, and revascularization. We used the HEART score to determine pretest ACS risk (low, intermediate, and high). To mitigate potential confounding, patients with and without early stress testing were matched within pretest risk strata in a 1:2 ratio using propensity scores.

RESULTS

Of 7127 potentially eligible patients, 895 (13%) received early stress testing. The analytic cohort included 895 patients with early stress testing matched to 1790 without early stress testing. The overall 30-day MACE rate in both the source and analytic population was 3%. There were no baseline imbalances after propensity score matching (P > 0.1 for more than 30 variables). There was no association between early stress testing and 30-day MACE [odds ratio, 1.0; 95% confidence interval (CI), 0.6-1.7]. There was no effect modification by pretest risk (low: odds ratio, 1.0; 95% CI, 0.2-3.7; intermediate: 1.2; 95% CI, 0.6-2.6; high: 0.4; 95% CI, 0.1-1.6).

CONCLUSIONS

Early stress testing is not associated with reduced MACE in patients evaluated for suspected ACS. Early stress testing may have limited value in populations with low MACE rate.

HEART Pathway Accelerated Diagnostic Protocol Implementation: Prospective Pre-Post Interrupted Time Series Design and Methods

Background

Most patients presenting to US Emergency Departments (ED) with chest pain are hospitalized for comprehensive testing. These evaluations cost the US health system >$10 billion annually, but have a diagnostic yield for acute coronary syndrome (ACS) of <10%. The history/ECG/age/risk factors/troponin (HEART) Pathway is an accelerated diagnostic protocol (ADP), designed to improve care for patients with acute chest pain by identifying patients for early ED discharge. Prior efficacy studies demonstrate that the HEART Pathway safely reduces cardiac testing, while maintaining an acceptably low adverse event rate.

Objective

The purpose of this study is to determine the effectiveness of HEART Pathway ADP implementation within a health system.

Methods

This controlled before-after study will accrue adult patients with acute chest pain, but without ST-segment elevation myocardial infarction on electrocardiogram for two years and is expected to include approximately 10,000 patients. Outcomes measures include hospitalization rate, objective cardiac testing rates (stress testing and angiography), length of stay, and rates of recurrent cardiac care for participants.

Results

In pilot data, the HEART Pathway decreased hospitalizations by 21%, decreased hospital length (median of 12 hour reduction), without increasing adverse events or recurrent care. At the writing of this paper, data has been collected on >5000 patient encounters. The HEART Pathway has been fully integrated into health system electronic medical records, providing real-time decision support to our providers.

Conclusions

We hypothesize that the HEART Pathway will safely reduce healthcare utilization. This study could provide a model for delivering high-value care to the 8-10 million US ED patients with acute chest pain each year.

ClinicalTrial

Clinicaltrials.gov NCT02056964; https://clinicaltrials.gov/ct2/show/NCT02056964 (Archived by WebCite at http://www.webcitation.org/6ccajsgyu)

Adherence to an Accelerated Diagnostic Protocol for Chest Pain: Secondary Analysis of the HEART Pathway Randomized Trial

OBJECTIVES

Accelerated diagnostic protocols (ADPs), such as the HEART Pathway, are gaining popularity in emergency departments (EDs) as tools used to risk stratify patients with acute chest pain. However, provider nonadherence may threaten the safety and effectiveness of ADPs. The objective of this study was to determine the frequency and impact of ADP nonadherence.

METHODS

A secondary analysis of participants enrolled in the HEART Pathway RCT was conducted. This trial enrolled 282 adult ED patients with symptoms concerning for acute coronary syndrome without ST-elevation on electrocardiogram. Patients randomized to the HEART Pathway (N = 141) were included in this analysis. Outcomes included index visit disposition, nonadherence, and major adverse cardiac events (MACEs) at 30 days. MACE was defined as death, myocardial infarction, or revascularization. Nonadherence was defined as: 1) undertesting-discharging a high-risk patient from the ED without objective testing (stress testing or coronary angiography) or 2) overtesting-admitting or obtaining objective testing on a low-risk patient.

RESULTS

Nonadherence to the HEART Pathway occurred in 28 of 141 patients (20%, 95% confidence interval [CI] = 14% to 27%). Overtesting occurred in 19 of 141 patients (13.5%, 95% CI = 8% to 19%) and undertesting in nine of 141 patients (6%, 95% CI = 3% to 12%). None of these 28 patients suffered MACE. The net effect of nonadherence was 10 additional admissions among patients identified as low-risk and appropriate for early discharge (absolute decrease in discharge rate of 7%, 95% CI = 3% to 13%).

CONCLUSIONS

Real-time use of the HEART Pathway resulted in a nonadherence rate of 20%, mostly due to overtesting. None of these patients had MACE within 30 days. Nonadherence decreased the discharge rate, attenuating the HEART Pathway's impact on health care use.

A Clinical Decision Rule to Identify Emergency Department Patients at Low Risk for Acute Coronary Syndrome Who Do Not Need Objective Coronary Artery Disease Testing: The No Objective Testing Rule

STUDY OBJECTIVE

We derive a clinical decision rule for ongoing investigation of patients who present to the emergency department (ED) with chest pain. The rule identifies patients who are at low risk of acute coronary syndrome and could be discharged without further cardiac testing.

METHODS

This was a prospective observational study of 2,396 patients who presented to 2 EDs with chest pain suggestive of acute coronary syndrome and had normal troponin and ECG results 2 hours after presentation. Research nurses collected clinical data on presentation, and the primary endpoint was diagnosis of acute coronary syndrome within 30 days of presentation to the ED. Logistic regression analyses were conducted on 50 bootstrapped samples to identify predictors of acute coronary syndrome. A rule was derived and diagnostic accuracy statistics were computed.

RESULTS

Acute coronary syndrome was diagnosed in 126 (5.3%) patients. Regression analyses identified the following predictors of acute coronary syndrome: cardiac risk factors, age, sex, previous myocardial infarction, or coronary artery disease and nitrate use. A rule was derived that identified 753 low-risk patients (31.4%), with sensitivity 97.6% (95% confidence interval [CI] 93.2% to 99.5%), negative predictive value 99.6% (95% CI 98.8% to 99.9%), specificity 33.0% (95% CI 31.1% to 35.0%), and positive predictive value 7.5% (95% CI 6.3% to 8.9%) for acute coronary syndrome. This was referred to as the no objective testing rule.

CONCLUSION

We have derived a clinical decision rule for chest pain patients with negative early cardiac biomarker and ECG testing results that identifies 31% at low risk and who may not require objective testing for coronary artery disease. A prospective trial is required to confirm these findings.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

State-of-the-Art Updates on Cardiac Computed Tomographic Angiography for Assessing Coronary Artery Disease

OPINION STATEMENT

Cardiac computed tomographic angiography (CCTA) is a noninvasive imaging modality that is increasingly useful for the evaluation of coronary artery disease (CAD). Over the past decade, CCTA has consistently demonstrated an excellent sensitivity for the detection and exclusion of coronary atherosclerosis in patients with stable or acute chest pain symptoms. Large prospective registries have repeatedly demonstrated the prognostic significance of the presence, extent, or absence of CAD by CCTA. In response to initial concerns, technical advances have permitted a dramatic reduction in patient radiation exposure with preserved image quality. For many patients, the radiation dose of CCTA is less than half of that with conventional myocardial perfusion imaging while providing significantly more anatomic information. Furthermore, CCTA's excellent spatial resolution is increasingly being used for noninvasive assessment of coronary plaque, including the detection of higher-risk vulnerable plaque and association between plaque characteristics and ischemia. Finally, new promising techniques that incorporate physiology with anatomy, such as CT-based fractional flow reserve (FFR-CT) and CT perfusion (CTP), are allowing for the noninvasive hemodynamic assessment of coronary stenoses and improvements in the specificity of CCTA findings. Such advances augur a coming transition when CCTA will be a first-line test for the detection, exclusion, and even management of CAD in many patients.

Performance of the 2-hour accelerated diagnostic protocol within the American College of Radiology Imaging Network PA 4005 cohort

OBJECTIVES

The 2-hour accelerated diagnostic protocol (ADAPT) is a decision rule designed to identify emergency department (ED) patients with chest pain for early discharge. Previous studies in the Asia-Pacific region demonstrated high sensitivity (97.9% to 99.7%) for major adverse cardiac events (MACE) at 30 days. The objective of this study was to determine the validity of ADAPT for risk stratification in a cohort of U.S. ED patients with suspected acute coronary syndrome (ACS).

METHODS

A secondary analysis of participants enrolled in the American College of Radiology Imaging Network (ACRIN) PA 4005 trial was conducted. This trial enrolled 1,369 patients at least 30 years old with symptoms suggestive of ACS. All data elements were collected prospectively at the time of enrollment. Each patient was classified as low risk or at risk by ADAPT. Early discharge rate and sensitivity for MACE, defined as cardiac death, myocardial infarction (MI), or coronary revascularization at 30 days, were calculated.

RESULTS

Of 1,140 patients with complete biomarker data, MACE occurred in 31 patients (2.7%). Among 551 of the 1,140 (48.3%, 95% confidence interval [CI] = 45.4% to 51.3%), ADAPT identified for early discharge; five of the 551 (0.9%, 95% CI = 0.3% to 2.1%) had MACE at 30 days. ADAPT was 83.9% (95% CI = 66.3% to 94.5%) sensitive, identifying 26 of 31 patients with MACE. Of the five patients identified for early discharge by ADAPT with MACE, there were no deaths, one patient with MI, and five with revascularizations.

CONCLUSIONS

In this first North American application of the ADAPT strategy, sensitivity for MACE within 30 days was 83.9%. One missed adverse event was a MI, with the remainder representing coronary revascularizations. The effect of missing revascularization events needs further investigation.

The HEART Pathway randomized trial: identifying emergency department patients with acute chest pain for early discharge

BACKGROUND

The HEART Pathway is a decision aid designed to identify emergency department patients with acute chest pain for early discharge. No randomized trials have compared the HEART Pathway with usual care.

METHODS AND RESULTS

Adult emergency department patients with symptoms related to acute coronary syndrome without ST-elevation on ECG (n=282) were randomized to the HEART Pathway or usual care. In the HEART Pathway arm, emergency department providers used the HEART score, a validated decision aid, and troponin measures at 0 and 3 hours to identify patients for early discharge. Usual care was based on American College of Cardiology/American Heart Association guidelines. The primary outcome, objective cardiac testing (stress testing or angiography), and secondary outcomes, index length of stay, early discharge, and major adverse cardiac events (death, myocardial infarction, or coronary revascularization), were assessed at 30 days by phone interview and record review. Participants had a mean age of 53 years, 16% had previous myocardial infarction, and 6% (95% confidence interval, 3.6%-9.5%) had major adverse cardiac events within 30 days of randomization. Compared with usual care, use of the HEART Pathway decreased objective cardiac testing at 30 days by 12.1% (68.8% versus 56.7%; P=0.048) and length of stay by 12 hours (9.9 versus 21.9 hours; P=0.013) and increased early discharges by 21.3% (39.7% versus 18.4%; P<0.001). No patients identified for early discharge had major adverse cardiac events within 30 days.

CONCLUSIONS

The HEART Pathway reduces objective cardiac testing during 30 days, shortens length of stay, and increases early discharges. These important efficiency gains occurred without any patients identified for early discharge suffering MACE at 30 days.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique Identifier: NCT01665521.

Death or revascularization among nonadmitted ED patients with low-positive vs negative troponin T results

STUDY OBJECTIVE

Compare outcomes among emergency department (ED) patients with low-positive (0.01-0.02 ng/mL) vs negative troponin T.

METHODS

Retrospective cohort study of nonadmitted ED patients with troponin testing at a tertiary-care hospital. Trained research assistants used a structured tool to review charts from all nonadmitted ED patients with troponin testing, 12/1/2009 to 11/30/2010. Outcomes of death and coronary revascularization were assessed at 30 days and 6 months via medical record review, Social Security Death Index searches, and patient contact.

RESULTS

There were 57596 ED visits; with 33388 (58%) discharged immediately, 6410 (11%) assigned to the observation unit, and 17798 (31%) admitted or other. Troponin was measured in 2684 (6.7%) of the nonadmitted cases. Troponin was negative in 2523 (94.0%), low positive in 78 (2.9%), and positive (≥0.03 ng/mL) in 83 (3.1%). Of troponin-negative cases, 0.8% (95% CI, 0.4-1.1%) died or were revascularized by 30 days, vs 2.8% (95% CI, 0.0-6.7%) of low-positive cases (risk difference [RD], 2.0%; 95% CI, -1.8 to 5.9%). At 6 months, the rates were 1.7% (95% CI, 1.1-2.2%) and 12.9% (95% CI, 5.0-20.7%) (RD, 11%; 95% CI, 3.3-19.1%). Death alone at 30 days occurred in 0.4% (95% CI, 0.1-0.6%) vs 1.3% (95% CI, 0.0-3.8%) (RD, 0.9%; 95% CI, -1.6 to 3.4%). Death at 6 months occurred in 1.2% (95% CI, 0.8-1.6%) vs 11.7% (95% CI, 4.5-18.9%) (RD, 10%; 95% CI, 3.3-17.7%).

CONCLUSION

Among patients not initially admitted, rates of death and coronary revascularization differed insignificantly at 30 days but significantly at 6 months. Detailed inspection of our results reveals that the bulk of the added risk at 6 months was due to non-cardiac mortality.

Coronary and cardiac computed tomography in the emergency room: current status and future directions

In the United States, chest pain is the second leading reason for patients to present to an emergency department (ED). Previously, those patients suspected to have acute coronary syndrome were monitored for 24 hours to determine the presence of serum biomarkers consistent with myocardial injury. However, more recently, imaging has been used to more efficiently triage these individuals and even discharge them directly from the ED. There are multiple cardiac imaging modalities; however, cardiac computed tomography now plays a significant role in the evaluation of patients with suspected acute coronary syndrome who present to the ED. In this review, we discuss the available state-of-the-art techniques for evaluating this cohort of patients, including clinical evaluation, serum biomarkers, and imaging options. Further, we analyze in detail evidence for the use of coronary computed tomography angiography to determine whether these patients can safely be discharged from the ED. Finally, we review some of the related future techniques that may become part of the accepted clinical management of these patients in the future.

Evaluation of novice reader diagnostic performance in coronary CT angiography using an advanced cardiac software package

Purpose

The purpose of this research was to evaluate whether a commercially available advanced cardiac software package for coronary CT angiography (CTA) interpretation may reliably assist inexperienced readers to screen for significant coronary artery stenoses.

Methods

Coronary CTA data sets of 61 consecutive patients with suspected coronary artery disease were evaluated by three novice readers with no experience in cardiac CT interpretation. In the first 15 patients, the novice readers were trained to use the advanced cardiac software package (includes automatic detection of coronary vessels, curved MPR and VRT reconstructions and a measurement too) knowing the results of an expert read. In the next 46 patients, the novice readers had to state whether there is a significant coronary artery stenosis (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$>$$\end{document}>50 %) and if they are confident with their diagnosis. The results of the novice readers were compared to the expert read.

Results

The 46 coronary CTA data sets contained 184 vessels with 15 stenoses in 9 patients. On a per-vessel analysis, novice reader 1/2/3 demonstrated 60 %/100 %/ 93% sensitivity, and 98 %/90 %/86 % specificity. Per patient, the readers diagnosed 36/28/29 cases correctly as free of stenoses, 6/9/8 correctly as having at least one stenosis, missed 3/0/1 cases with a stenosis and overdiagnosed 1/9/8 patients. Cohen’s kappa values for the three readers versus the expert were 0.60, 0.61 and 0.54. The three novice readers felt confident in the diagnosis of 36/33/30 patients. In these patients, they missed one significant stenosis, showed a sensitivity of 100 %/100 %/75 % and a specificity of 100 %/92 %/88 %.

Conclusions

The evaluated advanced cardiac software package successfully assists novice readers in interpreting coronary CTA data sets especially in ruling out significant coronary artery stenosis.