Lit Matters #1: “Safe to go?” Syncope vs Pre-Syncope Discharge Risk

Presyncope is not a benign shortcut version of syncope. In emergency department patients 40 and older without a serious diagnosis on initial workup, presyncope and syncope had similar 30-day serious cardiac event rates, while clinician risk estimates and admission decisions still diverged.

Presyncope and Syncope Risk

• Matched event rates: Thirty-day serious cardiac outcomes were essentially the same for presyncope and syncope, about 5% in each group, arguing against using loss of consciousness alone as a safety signal.
• Risk perception gap: Physicians estimated lower short-term risk for presyncope than for syncope despite similar outcomes, suggesting the label itself may bias bedside disposition.
• Admission rate split: Patients with presyncope were admitted less often than patients with syncope, with an absolute gap of 11.3%, even though downstream cardiac event rates were comparable.
• Low discharge event rate: Most discharged patients in both groups did well, with fewer than 1.1% having a serious cardiac outcome after leaving the ED. We get into the disposition nuance in the episode.
• Risk tool implications: These data support treating presyncope as part of the same risk-stratification conversation as syncope, especially when applying tools like the Canadian Syncope Risk Score and FAINT.