In 2018, the American College of Physicians (ACEP) released a Clinical Policy with management recommendations for patients presenting to the emergency department (ED) with concern for non-ST-elevation myocardial infarction (NSTEMI). Dr. Jason Woods hosted an episode of the ACEP E-QUAL Network podcast highlighting key aspects of the new policy. Dr. Woods was joined by lead writer Dr. Christian Tomaszewski from the University of California San Diego, and Dr. Michael Ross, Director of the Chest Pain Center at Emory University. Below are show notes reviewing the recommendations and the process involved in creating the clinical policy.

How is a clinical policy different than a practice guideline?

The National Guideline Clearinghouse (NGC), a public resource initiative of the Agency for Healthcare Research and Quality (AHRQ), provides rules and frameworks for evidence-based clinical practice guidelines. ACEP refers to clinical practice guidelines in Emergency Medicine (EM) as policies to denote the more prescriptive design process.

What was the process of drafting the policy?

Development of the 2018 ACEP NSTEMI Clinical Policy was a 2-year “labor of love.” Writers, methodologies, and committee members were required to be free from both financial and intellectual conflict of interest.

The clinical policy is a result of a systematic review and critical analysis of available medical literature. Clinical studies were graded on robustness, design, and class of evidence according to the ACEP policy development process which includes internal and external review.

Recommendations were categorized as reflecting high clinical certainty (Level A), moderate clinical certainty (Level B), or mixed clinical certainty (Level C) due to the heterogeneity of results, unclear effect magnitude, bias, among other factors.

What questions did the policy address?

Four critical questions were decided by consensus methods to address the evaluation and management of adult patients presenting to the ED with concern for NSTEMI.

1) If ST-elevation myocardial infarction is excluded, can a combination of bedside and laboratory evaluation in the ED identify patients at low risk for major adverse cardiac events (MACE)?
Level B recommendation: History, ECG, Age, Risk Factors, Troponin (HEART) score < 3 can be used as a clinical prediction tool for a 30-day MACE miss rate between 0-2%.
Level C recommendation: Thrombolysis in Myocardial Infarction (TIMI) score can be used to predict risk of 30-day MACE.

2) Can repeat Troponin testing in the ED be used to identify patients at low risk for MACE?
Level C recommendations:

1. • Conventional troponin testing at hour 0 and 3 in low risk (HEART score < 3) patients can predict and acceptable low risk for 30-day MACE.
   • A single high-sensitivity troponin less than the detectable limit on arrival to the ED or negative serial high-sensitivity troponin at hour 0 and 2 is predictive of a low rate of MACE.
   • Patients deemed to be low risk with a non-ischemic ECG and negative high-sensitivity troponin at 0 and 2 hours can be considered low risk for 30-day MACE, allowing for accelerated discharge from the ED.

3) In patients who have been ruled out for acute coronary syndromes (ACS), does advanced cardiac provocative testing prior to discharge from the ED reduce MACE?
Level B recommendation:  Do not routinely use advanced cardiac testing in low-risk patients who have been ruled out for ACS to further reduce 30-day MACE.
Level C recommendation: Arrange follow-up in 1-2 weeks for low-risk patients in whom ACS has been ruled out. If unable to arrange follow-up, consider observation and advanced testing prior to discharge.

4) Should patients with NSTEMI receive antiplatelet therapy in addition to aspirin in the ED?
Level C recommendation: P2Y12 inhibitors and glycoprotein IIb/IIIa inhibitors can be given in the ED or delayed until cardiac catheterization.

What questions remain?

1. The clinical policy does not address the “delta factor” involved in assessing changes to the cardiac marker levels that may be seen with repeat testing at set time points.
2. Duration of pain was not discretely addressed, and differences in real-world practice can exist depending on whether the time of onset or time of presentation is considered for defining repeat testing and observation length.
3. Shared decision-making was not factored into the selection of management steps.

Important points for consideration:

The 2018 ACEP Clinical Policy for NSTEMI was written for the evaluation of patients with suspicion for ACS who presented with chest pain. It does not apply to those presentations of ACS that are considered atypical in nature.

Read a more in-depth summary of the ACEP Clinical Policy on ALiEM. 

Interested in more of the ACEP-EQUAL Podcast?