Ep 128 Low Risk Chest Pain and High Sensitivity Troponin – A Paradigm Shift

This is EM Cases Episode 128 Low Risk Chest Pain and High Sensitivity Troponin - A Paradigm Shift Talk to any emergency doctor worth their salt, and they’ll tell you that it isn’t the wildly sick patients who keep them up at night - it’s the ones they sent home. Every disease has high risk and low risk populations, and every patient has diseases they are individually more or less likely to have. It’s a battle of odds, and the stakes couldn’t be higher. So fittingly, chest pain is a high risk topic, but has low risk patients that we need to identify accurately in the ED. In this podcast with Dr. Eddy Lang and world expert on troponin researcher Dr. Andrew McRae, we answer the not-so-simple questions: In the age of high sensitivity troponins and the HEART pathway, which low risk chest pain patients are safe to discharge home from the ED? What are the most useful historical factors to increase and decrease your pretest probability for ACS? Which cardiac risk factors have predictive value for ACS? Why should the words "troponitis" and "troponemia" be banned? How should high sensitivity troponin be interpreted differently than conventional troponin? Which is better for delta troponin interpretation - an absolute change in troponin or a percentage change? Which delta troponin is best - 1hr, 2hr or 3hr? What are the limitations of the HEART pathway for low risk chest pain? and many more.... Podcast production, sound design & editing by Anton Helman Written Summary and blog post by Anton Helman July, 2019 Cite this podcast as: Helman, A. McRae, A. Lang, E. Low Risk Chest Pain and High Sensitivity Troponin - A Paradigm Shift. Emergency Medicine Cases. July, 2019. https://emergencymedicinecases.com/low-risk-chest-pain-high-sensitivity-troponin. Accessed [date]. Correction July 30th, 2019: For hs-troponin T, the 2h delta to rule-out is <4ng/L and the delta to rule-in is >= 10ng/L. Defining low risk chest pain Patients at low risk for ACS ("low risk chest pain patients") are those who are hemodynamically stable, are without concerning features on history or examination, and do not have immediate objective evidence of myocardial ischemia on initial ECGs and biomarker testing. Consensus guidelines further define the low risk chest pain patient as having a < 1% risk of a Major Adverse Cardiac Event (MACE) or death at ≥ 30-days follow up [1], a threshold below which harm caused by further testing may outweigh any clinical benefit [2]. Predictive value of clinical features for ACS There is no combination of historical features that can accurately rule in or rule out ACS [3]. The rule for ACS presentations is: Atypical is typical [4]. * Up to 1/3 of pts with ACS have no CP at all [5]. * Populations most at risk for atypical presentations are women and patients with comorbidities that alter their ability to communicate (e.g. stroke, dementia) or alter their sensory perception of chest pain (e.g. diabetes, neuropathies) * The most frequent anginal equivalents in order of prevalence: SOB>weakness>unusual fatigue>sweating>dizziness * Risk factors for ACS presenting without chest pain include older patients (especially >85 years of age), women, diabetes, stroke and heart failure [6]. * Patients with comorbidities might be at an increased risk of ACS related to diagnostic error as a result of us anchoring on their usual complications Based on the TRAPID-AMI [7] and JAMA clinical exam series [8] the most predictive features of ACS include: * Radiation to both arms or right arm * Pain described as pressure * Associated with nausea or vomiting * Associated with sweating (especially sweating observed in the ED)