Syncope Time Frames for Adverse Events after Emergency Department Presentation: An Individual Patient Data...

Area of Science:

• Emergency Medicine
• Cardiology
• Clinical Epidemiology

Background:

• Effective management of syncope patients in the emergency department (ED) requires understanding adverse event incidence and timing.
• Syncope, a transient loss of consciousness, necessitates accurate risk stratification to guide treatment.
• Knowledge gaps exist regarding the long-term adverse event profile of syncope presentations in the ED.

Purpose of the Study:

• To conduct a meta-analysis determining the incidence and time frames of adverse events in adult patients presenting with syncope to the ED.
• To pool data from prospective observational studies to establish reliable event rates.
• To inform clinical decision-making and improve syncope management strategies.

Main Methods:

• Individual patient data were combined from nine prospective observational studies.
• Included were adult patients presenting with syncope to an emergency department.
• Adverse event rates were assessed at 24 hours, 72 hours, 7-10 days, 1 month, and 1 year post-ED evaluation.

Main Results:

• A total of 12,269 patients were included; mean age 53-73 years, 42-57% female.
• Pooled adverse event rates: 5.1% at 24h, 7.0% at 72h, 8.4% at 7-10 days, 10.3% at 1 month, 21.3% at 1 year.
• Pooled death rates: 0.2% at 24h, 0.3% at 72h, 0.5% at 7-10 days, 1% at 1 month, 5.9% at 1 year. Arrhythmia was the most common event.

Conclusions:

• The risk of death or life-threatening adverse events following syncope presentation to the ED is low.
• Bradycardia and supraventricular arrhythmias are the most frequent adverse events, primarily occurring within the initial 3 days.
• Prolonged ECG monitoring in short-stay ED units may benefit syncope patients.