RT Journal Article SR Electronic T1 Development of the Canadian Syncope Risk Score to predict serious adverse events after emergency department assessment of syncope JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E289 OP E298 DO 10.1503/cmaj.151469 VO 188 IS 12 A1 Venkatesh Thiruganasambandamoorthy A1 Kenneth Kwong A1 George A. Wells A1 Marco L.A. Sivilotti A1 Muhammad Mukarram A1 Brian H. Rowe A1 Eddy Lang A1 Jeffrey J. Perry A1 Robert Sheldon A1 Ian G. Stiell A1 Monica Taljaard YR 2016 UL http://www.cmaj.ca/content/188/12/E289.abstract AB Background: Syncope can be caused by serious conditions not evident during initial evaluation, which can lead to serious adverse events, including death, after disposition from the emergency department. We sought to develop a clinical decision tool to identify adult patients with syncope who are at risk of a serious adverse event within 30 days after disposition from the emergency department.Methods: We prospectively enrolled adults (age ≥ 16 yr) with syncope who presented within 24 hours after the event to 1 of 6 large emergency departments from Sept. 29, 2010, to Feb. 27, 2014. We collected standardized variables at index presentation from clinical evaluation and investigations. Adjudicated serious adverse events included death, myocardial infarction, arrhythmia, structural heart disease, pulmonary embolism, serious hemorrhage and procedural interventions within 30 days.Results: We enrolled 4030 patients with syncope; the mean age was 53.6 years, 55.5% were women, and 9.5% were admitted to hospital. Serious adverse events occurred in 147 (3.6%) of the patients within 30 days after disposition from the emergency department. Of 43 candidate predictors examined, we included 9 in the final model: predisposition to vasovagal syncope, heart disease, any systolic pressure reading in the emergency department < 90 or > 180 mm Hg, troponin level above 99th percentile for the normal population, abnormal QRS axis (< −30° or > 100°), QRS duration longer than 130 ms, QTc interval longer than 480 ms, emergency department diagnosis of cardiac syncope and emergency department diagnosis of vasovagal syncope (C statistic 0.88, 95% confidence interval [CI] 0.85–0.90; optimism 0.015; goodness-of-fit p = 0.11). The risk of a serious adverse event within 30 days ranged from 0.4% for a score of −3 to 83.6% for a score of 11. The sensitivity was 99.2% (95% CI 95.9%–100%) for a threshold score of −2 or higher and 97.7% (95% CI 93.5%–99.5%) for a threshold score of −1 or higher.Interpretation: The Canadian Syncope Risk Score showed good discrimination and calibration for 30-day risk of serious adverse events after disposition from the emergency department. Once validated, the tool will be able to accurately stratify the risk of serious adverse events among patients presenting with syncope, including those at low risk who can be discharged home quickly.