Outcomes in presyncope patients: a prospective cohort study

Abstract

Study objective: Presyncope is the sudden onset of a sense of impending loss of consciousness without losing consciousness (which differentiates it from syncope). Our goals are to determine the frequency of emergency department (ED) presyncope visits, management, 30-day outcomes, and emergency physicians' outcome prediction.

Methods: Our prospective study at 2 academic EDs included adults with presyncope and excluded patients with syncope, mental status changes, seizure, and significant trauma. We collected patient characteristics, ED management, cause (vasovagal, orthostatic, cardiac, or unknown) at the end of the ED visit, and 30-day outcomes. Serious outcomes included death, arrhythmia, myocardial infarction, structural heart disease, pulmonary embolism, and hemorrhage. We also collected physicians' confidence in assigning the cause and their prediction probability for 30-day serious outcomes.

Results: Presyncope constituted 0.5% of ED visits. We enrolled 881 patients: mean age 55.5 years, 55.9% women, and 4.7% hospitalized. Among 780 patients with 30-day follow-up, 40 (5.1%) experienced serious outcomes: death 0.3%, cardiovascular 3.1%, and noncardiac 1.8%. Of the 840 patients discharged home, 740 had follow-up data and 14 patients (1.9%) experienced serious outcomes after ED disposition. The area under the receiver operating characteristic curve for physician prediction probability was 0.58 (95% confidence interval 0.38 to 0.78). The incidence of serious outcomes was similar, whereas physician diagnostic confidence and prediction probability varied among the 4 causal groups.

Conclusion: Presyncope can be caused by serious underlying conditions. Emergency physicians had difficulty predicting patients at risk for serious outcomes after ED discharge. Future studies are needed to identify risk factors for serious outcomes after ED disposition.