Background: Most patients admitted to the hospital from the emergency department (ED) with syncope do not have a myocardial infarction (MI), yet a common practice is to draw serial cardiac enzymes.
Methods: To assess the value of serial cardiac enzymes in elderly patients who present to the ED with syncope, a retrospective chart review was performed on consecutive patients aged 65 and older with syncope in an urban teaching hospital ED between July 1, 1998 and June 30, 1999. Charts were screened for presenting history, cardiac risk factors, testing, and outcomes including acute coronary syndromes, MI, death, and patients returning to the ED or admitted within 72 hours of discharge.
Results: 319 patients met the study criteria of syncope with confirmed loss of consciousness in the absence of seizure or stroke. 141 of 228 admitted patients (62%) had creatine phosphokinase (CPK) drawn and 5% of these had Troponin I (TnI). 3 of 141 patients, or 2.1% (95% CI [confidence interval]: 0.04%-6.09%), had positive cardiac enzymes during their hospitalization. CPK was positive in all 3, and TnI, drawn in 1 patient, was also positive. Two of these patients had chest discomfort and ST segment and T-wave abnormalities on electrocardiogram (ECG) in addition to a syncopal event. The third patient had dementia and could not recall the details surrounding her syncopal event. In addition, her baseline ECG demonstrated a left bundle branch block, limiting ECG interpretation.
Conclusions: Cardiac enzymes may be of little additional value if drawn routinely on elderly patients with syncope who are admitted to the hospital from the ED, unless they have other signs or symptoms suggestive of myocardial ischemia.