There’s been a clear shift in the emergency medicine mindset toward chest pain over the past few years, including an explosion of literature and professional guidance in support of the history, electrocardiogram, age, risk factors, and troponin (HEART) score.1 The primary application of this and other similar rules is to support risk-stratification and the early discharge of patients with chest pain at low risk for acute coronary syndrome (ACS).
In fact, various strategies for early discharge have been enshrined in the guidelines from the American College of Cardiology since 2014.2 These guidelines support the use of not only such stalwarts as the Thrombolysis in Myocardial Infarction (TIMI) and Global Registry of Acute Coronary Events (GRACE) scores, but HEART, a modification of HEART called HEARTS3, and the Vancouver Rule. Suffice it to say, if you’re not at least risk-stratifying patients for early discharge using clinical judgement or an objective tool, you’re lagging.
However, this article isn’t about discharging patients with low-risk chest pain. This article discusses discharging the other 40–50 percent of emergency department patients with chest pain who don’t fall into such an optimal classification. For instance, a septuagenarian with non-obstructive coronary artery disease on a previous cardiac catheterization, a couple seconds of atypical chest pain, and an undetectable troponin I counts as a “moderate” risk by HEART. Or a 65-year-old male without any known risk factors and non-specific pain who falls into the “not low risk” classification of the Emergency Department Assessment of Chest Pain Score (EDACS).3 How should we manage the vast heterogeneous cohort of patients like these who aren’t in the low-risk strata?
It’s Two Questions
This question basically breaks down into two components, which people frequently stick together and address singly when evaluating the performance of these algorithmic approaches. These approaches try to pare down the cohort by defining certain discharge criteria in the emergency department, and they measure success by remaining free of major adverse cardiac events (MACE) for a certain period of time.
This approach seeks to prevent the dreaded, “Hey, remember that guy with chest pain you sent home last week?” follow-up conversation on a future shift. However, assessing safety for discharge truly breaks down into these two questions: 1) “Have I adequately ruled-out an acute coronary syndrome on today‘s visit,” and 2) “What follow-up or additional testing will prevent a future MACE?”
To answer question one, we rely upon the relevant presenting features of the chest pain, the electrocardiogram, and biomarker testing. In the vast majority of cases in which acute ischemia is not apparent or highly suspected, the limiting factor becomes biomarkers. In the past, concern over the relative lack of early sensitivity to cardiac ischemia led clinicians to routinely refer patients for admission or observation for repeat biomarker testing. However, in recent years, an explosion of new literature describes the early test characteristics of both conventional and highly-sensitive troponins, and it‘s clear the biomarker rule-out can be performed entirely within the emergency department.4