Acute Coronary Syndrome, Chest Pain
Conditions
Keywords
ACS, Acute Coronary Syndrome, Chest pain, Cardiac MRI, CMR, Risk Stratification, Emergency Department
Brief summary
The purpose of this study is to investigate the best way to evaluate patients with chest pain in the emergency department. It compares receiving treatment in an observation unit with admission to the hospital. Patients treated in the observation unit will undergo cardiac Magnetic Resonance Imaging (MRI) testing. Patients treated with hospital admission will undergo the testing their doctor determines is best for them. All patients will undergo follow up to find out if they have had any heart related events.
Detailed description
Almost half of patients presenting to the Emergency Department (ED) with possible cardiac chest pain are at intermediate risk for short term death or infarction. Most are admitted to the hospital for serial ECG's, cardiac biomarkers, cardiology consultation, and stress testing or coronary angiogram. However, the 2007 ACC/AHA guidelines suggest that these patients can be managed in an observation unit (OU). Recently, cardiac magnetic resonance imaging (CMR) has proven more accurate than traditional testing modalities for the diagnosis of acute coronary syndrome (ACS), and has also received endorsement from the American College of Cardiology (ACC)/American Heart Association (AHA) guidelines. Immediate application of CMR in an OU may improve health care utilization compared to standard hospital admission for intermediate risk patients. Research hypotheses: 1. Patients in an OU CMR protocol will have lower cost for the index hospitalization than standard care. 2. An OU CMR protocol for patients with intermediate risk chest pain will significantly improve the frequency of correct cardiovascular admission decisions when compared to standard care. Methods summary: 110 ED patients at intermediate risk for short-term death or infarction, with nondiagnostic Electrocardiograms (ECG) and normal initial cardiac biomarkers, will be randomized to standard care or OU CMR protocols. Subjects in the OU CMR protocol will undergo CMR perfusion and stress testing, followed by serial biomarkers. Standard care subjects will be admitted for usual cardiac testing. ACS (infarction, death, coronary revascularization, unstable angina) will be assessed by evaluation of hospital course and phone follow-up at 30 days. Cost of hospital care will be compared among groups.
Interventions
OTHERObservation unit care, coupled with cardiac MRI
After Emergency Department (ED) evaluation, patients are randomized to Observation unit care or standard inpatient care. Patients in the observation unit will also undergo a stress cardiac MRI. Patients in the usual care arm may undergo any desired testing, including cardiac MRI, as determined by their treating physician.
Sponsors
Wake Forest University Health Sciences
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age greater than or equal to 18 years of age at the time of enrollment * Chest discomfort or other symptoms consistent with possible Acute Coronary Syndrome (ACS) as indicated by the treating physician after obtaining an Electrocardiogram (ECG) and cardiac biomarkers for the patient's evaluation * Patient requires an inpatient evaluation for their chest pain * The treating physician feels the patient could be discharged home if cardiac disease was excluded * Thrombolysis in Myocardial Infarction (TIMI) risk score ≥ 2 OR physician clinical impression of intermediate or high likelihood that the symptoms represent ACS * Negative pregnancy test (if sexually active, female, and of childbearing age)
Exclusion criteria
* Initial troponin I \> 1.0 ng/ml * New ST-segment elevation on any electrocardiogram (≥ 1 mV) * New ST-segment depression on any electrocardiogram (≥ 2 mV) * Unable to lie flat * Hypotension (systolic \< 90 mm Hg) * Contra-indications to MRI(Pacemaker, defibrillator, cerebral aneurysm clips, metallic ocular foreign body, implanted devices, claustrophobia) * Patient refusal of medical record review and telephone follow-up at 30 days * Terminal diagnosis with life expectancy less than 3 months * Pregnancy per patient report or positive pregnancy test (Center for Medicare & Medicaid Services (CMS)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Cost of Index Hospitalization | Emergency Department (ED) arrival through hospital discharge, median length of stay was 28.1 hours | Index hospitalization refers to the hospital visit during which the participant was enrolled in the trial. The primary outcome is examining the cost for this visit. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Correct Admission Decision, Based Upon the Reference Standard of Acute Coronary Syndrome (ACS) at 30 Days | 30 Days | Participants with ACS and admitted or not experiencing ACS and discharged will be considered a correct admission decision. Remaining participants will be considered to have incorrect admission decisions. |
| The Number of Participants Randomized to the OU and Were Able to Complete CMR Imaging | Emergency Department (ED) arrival through hospital discharge | The number of participants able to complete the planned imaging sequences will be measured. |
| Number of Participants Who Utilized the Indicated Health Care Procedures | 30d, 3mo, 6mo, and 1 year | Measured as self report, assessed during telephone follow-up. |
| Adverse Events During Magnetic Resonance Imaging (MRI) Scanning | Occuring in the MRI scanning suite or within 30 minutes of the last image acquisition. | Any event leading to early termination of the MRI acquisition, or requiring intervention by a physician, will be considered an adverse event related to MRI, excluding physician termination of image acquisition due to concerns of cardiac ischemia. |
Countries
United States
Participant flow
Recruitment details
Participants were recruited from the emergency department January 2008 - March 2009.
Pre-assignment details
Once consented, no participants were excluded from the trial prior to group assignment.
Participants by arm
| Arm | Count |
|---|---|
| Emergency Department (ED) Observation Unit Emergency Department observation unit - Cardiac Magnetic Resonance Imaging (MRI) Protocol. Patients will be transferred to the observation unit and undergo a stress cardiac MRI evaluation. | 53 |
| Usual Care This is the comparison arm. Patients are admitted to the hospital and undergo usual care. | 57 |
| Total | 110 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Lost to Follow-up at 30 days | 2 | 0 |
Baseline characteristics
| Characteristic | Emergency Department (ED) Observation Unit | Usual Care | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 8 Participants | 10 Participants | 18 Participants |
| Age, Categorical Between 18 and 65 years | 45 Participants | 47 Participants | 92 Participants |
| Region of Enrollment United States | 53 participants | 57 participants | 110 participants |
| Sex: Female, Male Female | 28 Participants | 27 Participants | 55 Participants |
| Sex: Female, Male Male | 25 Participants | 30 Participants | 55 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 6 / 53 | 4 / 57 |
| serious Total, serious adverse events | 2 / 53 | 7 / 57 |
Outcome results
Primary
Cost of Index Hospitalization
Index hospitalization refers to the hospital visit during which the participant was enrolled in the trial. The primary outcome is examining the cost for this visit.
Time frame: Emergency Department (ED) arrival through hospital discharge, median length of stay was 28.1 hours
Population: All participants were analyzed based on intention to treat.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Emergency Department (ED) Observation Unit | Cost of Index Hospitalization | 2062 US Dollars |
| Usual Care | Cost of Index Hospitalization | 2680 US Dollars |
Comparison: H0: The median costs are not different among the study groups. HA: The median cost is different among groups. Power calculation was based on detecting a mean cost difference of $2000. Data was found to be non-normally distributed and therefore nonparametric comparisons were implemented.95% CI: [336, 811]Hodges-Lehmann (median cost difference)
Secondary
Adverse Events During Magnetic Resonance Imaging (MRI) Scanning
Any event leading to early termination of the MRI acquisition, or requiring intervention by a physician, will be considered an adverse event related to MRI, excluding physician termination of image acquisition due to concerns of cardiac ischemia.
Time frame: Occuring in the MRI scanning suite or within 30 minutes of the last image acquisition.
Population: Only participants undergoing Cardiac MRI scanning are eligible for this endpoint. Only 49 of the 53 participants randomized to observation unit arm underwent CMR testing. Nine participants in the usual care arm underwent CMR testing.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Emergency Department (ED) Observation Unit | Adverse Events During Magnetic Resonance Imaging (MRI) Scanning | 3 Participants |
| Usual Care | Adverse Events During Magnetic Resonance Imaging (MRI) Scanning | 1 Participants |
Secondary
Correct Admission Decision, Based Upon the Reference Standard of Acute Coronary Syndrome (ACS) at 30 Days
Participants with ACS and admitted or not experiencing ACS and discharged will be considered a correct admission decision. Remaining participants will be considered to have incorrect admission decisions.
Time frame: 30 Days
Population: 4 participants (3 in the usual care group and 1 in the ED obs unit group) left Against Medical Advice (AMA) prior to completion of their evaluation and were excluded from this analysis. Analysis was per intention to treat.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Emergency Department (ED) Observation Unit | Correct Admission Decision, Based Upon the Reference Standard of Acute Coronary Syndrome (ACS) at 30 Days | 43 Participants |
| Usual Care | Correct Admission Decision, Based Upon the Reference Standard of Acute Coronary Syndrome (ACS) at 30 Days | 6 Participants |
Comparison: H0: There is no difference in correct cardiovascular admission decisions among groups.~Ha: A difference exists among study groups. Sample size was based upon 47 analyzable participants per study arm were required to provide 88% power to detect a 30% difference in the outcome.p-value: <0.001Fisher Exact
Secondary
Number of Participants Who Utilized the Indicated Health Care Procedures
Measured as self report, assessed during telephone follow-up.
Time frame: 30d, 3mo, 6mo, and 1 year
Population: Data reported through 30 days. Follow-up with participants is ongoing. Results will be updated once follow-up is complete.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Emergency Department (ED) Observation Unit | Number of Participants Who Utilized the Indicated Health Care Procedures | Cardiac related office visit | 7 Participants |
| Emergency Department (ED) Observation Unit | Number of Participants Who Utilized the Indicated Health Care Procedures | Cardiac related ED visit | 0 Participants |
| Emergency Department (ED) Observation Unit | Number of Participants Who Utilized the Indicated Health Care Procedures | Cardiac Catheterization | 0 Participants |
| Emergency Department (ED) Observation Unit | Number of Participants Who Utilized the Indicated Health Care Procedures | Stress Test | 0 Participants |
| Emergency Department (ED) Observation Unit | Number of Participants Who Utilized the Indicated Health Care Procedures | Cardiac related hospitalization | 0 Participants |
| Emergency Department (ED) Observation Unit | Number of Participants Who Utilized the Indicated Health Care Procedures | Cardiac related procedures | 0 Participants |
| Emergency Department (ED) Observation Unit | Number of Participants Who Utilized the Indicated Health Care Procedures | Resting Echocardiogram | 0 Participants |
| Usual Care | Number of Participants Who Utilized the Indicated Health Care Procedures | Resting Echocardiogram | 1 Participants |
| Usual Care | Number of Participants Who Utilized the Indicated Health Care Procedures | Cardiac related office visit | 4 Participants |
| Usual Care | Number of Participants Who Utilized the Indicated Health Care Procedures | Stress Test | 1 Participants |
| Usual Care | Number of Participants Who Utilized the Indicated Health Care Procedures | Cardiac related ED visit | 4 Participants |
| Usual Care | Number of Participants Who Utilized the Indicated Health Care Procedures | Cardiac related procedures | 4 Participants |
| Usual Care | Number of Participants Who Utilized the Indicated Health Care Procedures | Cardiac related hospitalization | 3 Participants |
| Usual Care | Number of Participants Who Utilized the Indicated Health Care Procedures | Cardiac Catheterization | 3 Participants |
Secondary
The Number of Participants Randomized to the OU and Were Able to Complete CMR Imaging
The number of participants able to complete the planned imaging sequences will be measured.
Time frame: Emergency Department (ED) arrival through hospital discharge
Population: All participants randomized to the Observation Unit - Cardiac Magnetic Resonance Imaging (OU-CMR) arm were analyzed based on intention to treat.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Emergency Department (ED) Observation Unit | The Number of Participants Randomized to the OU and Were Able to Complete CMR Imaging | 46 Participants |