The fourth and last question looks at the role of early antiplatelet therapy in patients with acute NSTEMI and focuses on timing. Because of early literature and general consensus on the accepted use of heparin and enoxaparin, the literature search and recommendations targeted newer oral antiplatelet agents. The goal was to ensure emergency physicians were not held accountable for timely administration of such agents if such delays were not associated with worse outcomes.
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ACEP Now: Vol 37 – No 11 – November 2018For each critical question, a structured literature review was performed, evidence was systematically graded (see Table 1), and evidence-based recommendations were presented.
Critical Questions
1. In adult patients without evidence of ST-elevation ACS, can initial risk stratification be used to predict a low rate of 30-day MACE?
Patient Management Recommendations
- Level A recommendations. None specified.
- Level B recommendations. In adult patients without evidence of ST-elevation ACS, the history, ECG, age, risk factors, and troponin (HEART) score can be used as a clinical prediction instrument for risk stratification. A low score (≤3) predicts 30-day MACE miss rate within a range of 0 to 2 percent.
- Level C recommendations. In adult patients without evidence of ST-elevation ACS, other risk-stratification tools, such as thrombolysis in myocardial infarction (TIMI), can be used to predict the rate of 30-day MACE.
2. In adult patients with suspected acute NSTE ACS, can troponin testing within three hours of ED presentation be used to predict a low rate of 30-day MACE?
Patient Management Recommendations
- Level A recommendations. None specified.
- Level B recommendations. None specified.
- Level C recommendations.
- In adult patients with suspected acute NSTE ACS, conventional troponin testing at 0 and 3 hours among low-risk ACS patients (defined by HEART score 0 to 3) can predict an acceptable low rate of 30-day MACE.
- A single high-sensitivity troponin result below the level of detection on arrival to the emergency department or negative serial high-sensitivity troponin results at 0 and 2 hours are predictive of a low rate of 30-day MACE.
- In adult patients with suspected acute NSTE ACS who are determined to be low risk based on validated accelerated diagnostic pathways that include a nonischemic ECG result and negative serial high-sensitivity troponin testing results both at presentation and at 2 hours can predict a low rate of 30-day MACE allowing for an accelerated discharge pathway from the emergency department.
3. In adult patients with suspected NSTE ACS in whom acute myocardial infarction has been excluded, does further diagnostic testing (eg, provocative, stress test, computed tomography [CT] angiography) for ACS prior to discharge reduce 30-day MACE?
Patient Management Recommendations
- Level A recommendations. None specified.
- Level B recommendations. Do not routinely use further diagnostic testing (CT coronary angiography, stress testing, myocardial perfusion imaging) prior to discharge in low-risk patients in whom acute myocardial infarction has been ruled out to reduce 30-day MACE.
- Level C recommendations. Arrange follow-up in one to two weeks for low-risk patients in whom myocardial infarction has been ruled out. If no follow-up is available, consider further testing or observation prior to discharge (consensus).
4. Should adult patients with acute NSTEMI receive immediate antiplatelet therapy in addition to aspirin to reduce 30-day MACE?
Patient Management Recommendations
- Level A recommendations. None specified.
- Level B recommendations. None specified.
- Level C recommendations. P2Y12 inhibitors and glycoprotein IIb/IIIa inhibitors may be given in the emergency department or delayed until cardiac catheterization.
In conclusion, patients who present with chest pain with low risk for ACS (eg, HEART score ≤3) and a normal troponin at 0 and 3 hours post-presentation may be discharged safely, with less than a 2 percent risk of subsequent 30-day MACE. The advent of high-sensitivity troponins will help accelerate this rule-out protocol. In such low-risk cases, we could find no data to support subsequent noninvasive testing. Our ultimate goal should be to prevent harm from missing MACE, but also from overtesting patients. Finally, our last question confirms that it is acceptable to delay further antiplatelet therapy, beyond heparin, especially if there are concerns over potential adverse bleeding or competing priorities.
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One Response to “How to Manage Suspected Non–ST-Elevation Acute Coronary Syndrome”
December 2, 2018
Jerry W. Jones, MD FACEP FAAEMOverall, a good presentation and I do agree with many of your views though there are a few statements that give me pause.
“Most emergency physicians strive to attain a miss rate of less than 1 percent. However, it is questionable if the benefits of further testing outweigh the risks of harm of untreated disease once that threshold reaches 2 percent, which the committee felt was a more realistic expectation. With shared decision making, patients may be willing to accept rates higher than those to which physicians hold themselves accountable.”
0% rate of MACE remains the holy grail of all physicians treating patients with chest pain and especially emergency physicians. I think every ER physician should strive for 0% MACE, no matter HOW unattainable that figure may realistically be. Aiming for 2% will only result in figures higher than 2%. And I can’t imagine trying to talk a patient into leaving the ER with a potential for MACE greater than that with which I myself would feel comfortable. That just seems hypocritical and unethical to me. At some point we must ask ourselves, “Are we working for the patient or for an insurance company?” In the quote above, you essentially ask if it is worth trying to reduce incidents of MACE from 2% to less than 1%. Worth to whom – the patient or the insurance companies? These percentages are not spanning a career in EM – many of us will reach those percentages every few months.