How Does the San Francisco Syncope Rule Perform in Canada?
The rule had a sensitivity of 90% for predicting serious outcomes at 30 days
Patients with syncope often are admitted to the hospital despite negative
emergency department (ED) evaluations. The San Francisco Syncope Rule was
developed to identify syncope patients who are at sufficiently low risk for
serious outcomes to be safely discharged home after ED evaluation. The rule
classifies patients as high risk if they have histories of congestive heart
failure, hematocrit <30%,>
or triage systolic blood pressure <90>
to have 96% and 98% sensitivity for predicting serious outcomes at 7 days
and 30 days, respectively, but has not performed as well in subsequent
validation studies in the U.S. and Australia, where sensitivities ranged
from 74% to 90% (JW Emerg Med Sep 19 2008 and JW Emerg Med Jun 8 2007).
To evaluate performance of the rule in Canada, researchers retrospectively
applied the rule to 505 patients who presented to a single tertiary care
hospital with syncope during an 18-month period. Serious outcomes were
defined as death, myocardial infarction, arrhythmia, pulmonary embolism,
stroke, subarachnoid hemorrhage, significant bleeding, any procedural
intervention to treat a related cause of syncope, any condition causing or
likely to cause a return emergency visit, and hospitalization for a related
event. Overall, 9.7% of patients had serious outcomes within 30 days. The
rule had a sensitivity of 90% for predicting these outcomes.
Comment: The results of this study are consistent with those from other
validation studies. The San Francisco Syncope Rule will likely need to be
improved and then validated before it is adopted in practice. Until then,
clinical judgment should continue to guide treatment and disposition.
— Richard D. Zane, MD, FAAEM
Published in Journal Watch Emergency Medicine