TOPLINE:

Adults aged 40 years or older presenting to the emergency department (ED) with presyncope (near-fainting) or syncope (fainting) had similar rates of 30-day serious cardiac outcomes (5.2% vs 4.7%), although physicians estimated a higher risk for patients with syncope during their ED assessments.

METHODOLOGY:

• Researchers conducted a secondary analysis of a prospective, observational, multicenter cohort study across six urban US EDs between 2020 and 2024.
• The cohort included patients (age ≥ 40 years) who presented with either syncope (n = 721) or presyncope (n = 542) and did not have a serious acute diagnosis during the index visit; baseline characteristics were similar between the groups.
• Syncope was defined as a brief loss of consciousness with spontaneous return to baseline neurologic function, and presyncope was defined as the sensation of impending loss of consciousness without actual loss.
• The primary outcome was a serious cardiac event (death, significant arrhythmia, myocardial infarction, new structural heart disease, cardiac arrest, or major cardiac intervention) within 30 days of the index ED visit. Assessment was performed using electronic chart review and phone follow-up.

TAKEAWAY:

• Serious cardiac outcomes within 30 days were similar between the groups: 4.7% for syncope and 5.2% for presyncope (odds ratio, 1.13; risk difference [RD], -0.45%). Inter‑rater agreement for outcome detection was high.
• The mean physician-estimated risk for serious cardiac outcomes was higher for syncope than for presyncope (7.6% vs 5.3%; RD, 2.3%).
• Hospital admission rates were higher for syncope than for presyncope (49.5% vs 38.2%; RD, 11.3%), as was echocardiography use (37.9% vs 28.4%).
• Rates of adverse outcomes after discharge were similar for syncope (0.8%; n = 6) and presyncope (1.1%; n = 6; RD, -0.27%). Arrhythmia patterns differed (for symptomatic supraventricular tachycardia, 5 patients with syncope vs 12 patients with presyncope and for brady/ventricular rhythms, 13 patients with syncope vs 6 patients with presyncope), but overall arrhythmia rates were similar (syncope, 2.5% vs presyncope, 3.5%).

IN PRACTICE:

"Patients with unexplained presyncope and syncope had similar rates of serious cardiac outcomes at 30 days after their ED visit. Patients with syncope had a higher mean physician-estimated risk and were more likely to be admitted," the authors wrote. "Future research should be directed at better understanding how resource utilization can be optimized for both ED patients with syncope and presyncope to safely reduce low-yield health care services," they added.

SOURCE:

The study was led by Edward H. Suh, MD, Columbia University Irving Medical Center, New York City. It was published online on September 23, 2025, in the Annals of Emergency Medicine.

LIMITATIONS:

The study was limited by potential selection bias from significant nonenrollment of screened patients. Results could not be generalized beyond urban academic centers and were not applicable to patients younger than 40 years. Some patients lost to follow-up may have experienced serious outcomes. Assessment of outcomes via patient self-report and chart review by investigators who were not fully blinded may have introduced bias. The study was not powered to detect differences between cardiac outcome subtypes, such as supraventricular vs ventricular tachycardias.

DISCLOSURES:

The study was funded by the National Heart, Lung, and Blood Institute of the National Institutes of Health. The Irving Institute for Clinical and Translational Research at Columbia University provided support by hosting the REDCap platform. Some authors reported having financial or employment ties with various sources. Details are provided in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.