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.