Sex-based analysis of characteristics, management, and outcomes of patients presenting to the emergency department with syncope

Syncope is a common emergency department (ED) presentation and can be caused by serious conditions not evident on initial ED evaluation. Research into sex-based differences among ED patients presenting with syncope is lacking. We sought to compare clinical characteristics, management, risk stratification and serious outcomes between male and female ED syncope patients, assess the impact of sex on outcomes after adjusting for comorbidities and Canadian Syncope Risk Score predictors, and evaluate the change in performance of the Canadian Syncope Risk Score with the addition of sex. We conducted a secondary analysis of the Canadian Syncope Risk Score derivation and validation study cohorts, comparing patient characteristics, ED management and outcomes between male and female patients presenting with syncope, using descriptive statistics and logistic regression models. Of 9539 total patients, 5190 (54.4%) were female. Male patients were older, had more comorbidities, received more testing in the ED, had longer lengths of stay, were more frequently hospitalized and were more likely to have serious outcomes than females. The association between male sex and serious outcomes persisted after controlling for age, arrival by ambulance, hypertension, diabetes, coronary artery disease, atrial fibrillation or flutter, valvular heart disease, and congestive heart failure (OR=1.73, p<0.001) and Canadian Syncope Risk Score predictors (OR =1.45, p=0.005). However, adding sex to the Canadian Syncope Risk Score model did not significantly increase the area under the receiver operating characteristic curve (difference = 0.0002, p=0.90). Male ED syncope patients tended to have more risk factors than females, underwent more investigations, and were more likely to have serious outcomes even when controlling for comorbidities. While clinicians should recognize these sex-based differences, they can continue to rely on the Canadian Syncope Risk Score in its current form for risk stratification as incorporating sex did not improve model performance.