Do outcomes of near syncope parallel syncope?

Limited information on the evaluation of emergency department (ED) patients complaining of "near syncope" exists. Multiple studies of syncope exclude near syncope claiming near syncope is poorly defined and its definition is nonuniform.

The aim of this study was to determine the incidence of critical interventions or adverse outcomes associated with near syncope and compare these outcomes with syncope.

Prospective, observational study enrolling (August 2007-October 2008) consecutive ED patients (age, ≥18 years) presenting with near syncope was conducted. Near syncope was defined as an episode in which the patient felt they might lose consciousness but did not. Critical intervention/adverse outcome was defined as hemorrhage, cardiac ischemia/intervention, alteration in antidysrhythmics, pacemaker/defibrillator placement, sepsis, stroke, death, dysrhythmia, sepsis, pulmonary embolus, or carotid stenosis. Primary outcome was an adverse outcome or critical intervention in hospital or less than 30 days. Near syncope and syncope outcomes and admission rates were compared using the χ(2) test.

After 1870 patients were screened, 244 met the study definition. Of the 244 patients, follow-up was achieved in 242 (99%). Emergency department hospitalization or 30-day adverse outcomes occurred in 49 (20%) of 244 compared with 68 (23%) of 293 of patients with syncope (P = .40). The most common adverse outcomes/critical interventions were hemorrhage (n = 6), bradydysrhythmia (n = 6), alteration in antidysrhythmics (n = 6), and sepsis (n = 10). Of patients with near syncope, 49% were admitted compared with 69% with syncope (P = .001).

Patients with near syncope are as likely those with syncope to experience critical interventions or adverse outcomes; however, near-syncope patients are less likely to be admitted. Given similar risk of adverse outcomes for near syncope and syncope, future studies are warranted to improve the treatment of ED patients with near syncope.