Applying the Boston syncope criteria to near syncope.

Background: We recently demonstrated that near-syncope patients are as likely as syncope patients to experience adverse outcomes. The Boston Syncope Criteria (BSC) identify patients with syncope unlikely to have adverse outcomes and reduce hospitalizations. It is unclear whether these guidelines could reduce hospitalization in near syncope as well.

Objective: To determine if BSC accurately predict which near-syncope patients require hospitalization.

Methods: A prospective observational study enrolled from August 2007 to October 2008 consecutive emergency department (ED) patients (aged > 18 years) with near syncope. BSC were first employed assuming that any patient with risk factors for adverse outcomes should be admitted, and then utilized using a modified rule: if the etiology of near syncope is dehydration or vasovagal, and ED work-up is normal, patients may be discharged even with risk factors. Outcomes were identified by chart review and 30-day follow-up calls.

Results: Of 244 patients with near syncope, 111 were admitted, with 49 adverse outcomes. No adverse outcomes occurred among discharged patients. If BSC had been followed strictly, another 41 patients with risk factors would have been admitted and 34 discharged, a 3% increase in admission rate. However, using the modified criteria, only 68 patients would have required admission, a 38% reduction in admission, with no missed adverse outcomes on follow-up.

Conclusion: Although near-syncope patients may have risk factors for adverse outcomes similar to those with syncope, if the etiology of near syncope is dehydration or vasovagal, and ED work-up is normal, these patients may be discharged even with risk factors.