Emergency Department Management of Non–ST-Segment Elevation Myocardial Infarction

Points and Pearls Excerpt

• Approximately 2% of patients presenting to an ED with acute coronary syndromes (ACS) are misdiagnosed and subsequently discharged.
• Misdiagnosis is more common among women aged < 55 years, and all patients of nonwhite ethnicity, patients with the presenting complaint of dyspnea, and patients with normal or nondiagnostic ECGs.
• Failure to hospitalize patients with ACS nearly doubles their mortality risk.
• The 1-year case fatality rate for patients with NSTEMI (non–ST-segment elevation myocardial infarction) is ≈ 25%, more than double that of STEMI.
• The American Heart Association and American College of Cardiology (AHA/ACC) guidelines on NSTEMI have been criticized due to potential conflicts of interest with the pharmaceutical industry.

Most Important References

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• Tataris KL, Mercer MP, Govindarajan P. Prehospital aspirin administration for acute coronary syndrome (ACS) in the USA: an EMS quality assessment using the NEMSIS 2011 database. Emerg Med J. 2015;32(11):876-881. (Retrospective analysis; 198,231 patients)
• Body R, Carley S, Wibberley C, et al. The value of symptoms and signs in the emergent diagnosis of acute coronary syndromes. Resuscitation. 2009;81(3):281-286. (Prospective observational study; 796 patients)
• Neumann JT, Sörensen NA, Schwemer T, et al. Diagnosis of myocardial infarction using a high-sensitivity troponin I 1-hour algorithm. JAMA Cardiol. 2016;1(4):397-404. (Prospective validation study; 4009 patients)
• Backus BE, Six AJ, Kelder JC, et al. Chest pain in the emergency room: a multicenter validation of the HEART Score. Crit Pathw Cardiol. 2010;9(3):164-169. (Retrospective analysis; 910 patients)
• Chen ZM, Jiang LX, Chen YP, et al. Early intravenous then oral metoprolol in 45,852 patients with acute myocardial infarction: randomised placebo-controlled trial. Lancet. 2005;366(9497):1622-1632. (Randomized controlled trial; 45,852 patients)
• Fanning JP, Nyong J, Scott IA, et al. Routine invasive strategies versus selective invasive strategies for unstable angina and non-ST elevation myocardial infarction in the stent era. Cochrane Database Syst Rev. 2016(5):CD004815. (Meta-analysis; 8915 patients)
• de Winter RJ, Windhausen A, Cornel JH, et al. Early invasive versus selectively invasive management for acute coronary syndromes. N Engl J Med. 2005;353(11):1095-1104. (Randomized controlled trial; 1200 patients)
• Fox KA, Poole-Wilson P, Clayton TC, et al. 5-year outcome of an interventional strategy in non-ST-elevation acute coronary syndrome: the British Heart Foundation RITA 3 randomised trial. Lancet. 2005;366(9489):914-920. (Randomized controlled trial; 1810 patients)