Explore This IssueACEP Now: Vol 40 – No 09 – September 2021
Emergency department evaluations for chest pain are common, accounting for approximately 5 percent of all ED visits. Up to 40 percent of these patients return to the emergency department with recurrent chest pain within one year.1 The intensity of evaluation for acute coronary syndrome (ACS) may vary—some patients may have received prior stress testing, coronary CT angiography, or even cardiac catheterization. Although risk stratification tools such as the History, ECG, Age, Risk factors, and Troponin (HEART) score are widely used to help determine disposition of patients with chest pain, there is little guidance regarding patients with recurrent chest pain who have had a prior evaluation. How much should a prior negative stress test or cardiac catheterization guide the medical decision making?
Enter the Society for Academic Emergency Medicine Guidelines for Reasonable and Appropriate Care in the Emergency Department (GRACE) on recurrent chest pain. This is the first of a clinical practice guideline series aimed at de-implementing low-value practices within emergency medicine. These guidelines attempt to make recommendations for patients who present with low-risk chest pain, defined as those deemed low risk by a validated scoring system (eg, HEART score <4) who present to an emergency department with an evaluation for ACS at least twice in a 12-month period. The primary outcomes assessed were major adverse cardiac events (MACE), including acute myocardial infarction (AMI), need for percutaneous coronary intervention (PCI) or bypass, and death. Nearly all the recommendations in this document are based on low-quality evidence, mostly from studies indirectly answering the questions, as few addressed recurrent evaluations specifically.
Serial Versus Single Troponin
Recommendation: “In adult patients with recurrent, low-risk chest pain, for greater than 3 h duration we suggest a single, high-sensitivity troponin below a validated threshold to reasonably exclude ACS within 30 days.”
This recommendation is congruent with other clinical policies, including the 2018 ACEP clinical policy on suspected ACS, as MACE within 30 days was 0.5 percent, falling below the acceptable miss rate of 1 to 2 percent.2 There are two key components to this recommendation. First, a single troponin only applies to high-sensitivity troponin, as there is insufficient evidence for conventional troponin assays. Second, the chest pain must be more than three hours in duration, as very few patients in the included studies presented to the emergency department earlier.
Repeat Stress Testing
Recommendation: “In adult patients with recurrent, low-risk chest pain, and a normal stress test within the previous 12 months, we do not recommend repeat routine stress testing as a means to decrease rates of MACE at 30 days.”
Ideally, stress testing would identify patients with intervenable coronary artery disease and reduce MACE; however, studies assessing stress testing of ED patients with chest pain have not found a reduction in MACE at 30 days. Yet, stress testing carries potential harms from downstream testing and procedures as false positive tests are not uncommon.
Outpatient Versus Inpatient Management
Recommendation: In adult patients with recurrent, low-risk chest pain and either no occlusive coronary artery disease (CAD) (0 percent stenosis) or non-obstructive (<50 percent stenosis) CAD on prior angiography within five years, the authors recommend referral for expedited outpatient testing as warranted rather than admission for inpatient evaluation.
These recommendations are possibly the most “practice changing” in the document. Patients with nonobstructive CAD have very low incidence of AMI or death in the two years following the catherization—fewer than one event in 100 patients followed for two years. The event rate is even lower for those with no occlusive CAD. As a result, hospital admission for ACS evaluation is likely to generate more harms (allergic reactions, procedural risks, stress, and cost) than benefit.
Recommendation: “In adult patients with recurrent, low-risk chest pain and prior [coronary computed tomographic angiography] CCTA within the past 2 years with no coronary stenosis, we suggest no further diagnostic testing other than a single, high-sensitivity troponin below a validated threshold to exclude ACS within that 2-year time frame.”
This recommendation echoes the one above—the recognition of the unlikely benefit and potential harms of hospitalization in a very low-risk group. A large registry found that the risk of AMI, mortality, and MACE were all well under 1 percent in patients with a CCTA without coronary stenosis who were followed for two years. Although identification of this ultra-low-risk population might be seen as a benefit of CCTA, the test is associated with increased downstream testing and interventions of uncertain long-term patient-oriented benefit.
Screening and Referral for Depression and Anxiety
Recommendation: In adult patients with recurrent, low-risk chest pain, the authors recommended using depression and anxiety screening tools and referral for anxiety or depression management.
The evidence basis for these recommendations is minimal and rooted in observational data finding variable results for an association between chest pain recurrence and anxiety and depression. At this time, the evidence doesn’t provide sufficient information on what to do if a patient “screens in” for depression or anxiety. As emergency physicians, we must be cautious in attributing medical issues to mental health and recognize that a concurrent diagnosis of anxiety may cause us to anchor and potentially miss a serious diagnosis.
The recommendations in this guideline are rooted in low-quality evidence and therefore are a weak set of treatment options for emergency physicians. Yet, they represent a critical step in ED evaluations—guidance for clinicians to stop performing low-value or wasteful care. In medicine, we often strive for a “zero miss” culture, despite the impossibility of this aim and recommendations to embrace a 1 to 2 percent missed diagnosis rate in ACS. We often fail to consider the iatrogenic harms and patient and societal costs associated with overtesting and more intensive care. The GRACE guidelines may empower some clinicians to more thoughtfully and rationally evaluate patients with low-risk recurrent chest pain by providing reassurance that “more” may not necessarily be beneficial to the patient.
Dr. Westafer (@LWestafer) is assistant professor of emergency medicine and emergency medicine research fellowship director at the University of Massachusetts Medical School–Baystate and co-host of FOAMcast.