The ability of Canadian Syncope risk score in differentiating cardiogenic and non-cardiogenic syncope; a cross-sectional study.

INTRODUCTION: Determining the underlying etiology of syncope provides valuable prognostic information and expedites the implementation of a therapeutic strategy. This study aimed to evaluate the ability of Canadian Syncope Risk Score (CSRS) in differentiating cardiogenic and non-cardiac syncope.

METHODS: The present diagnostic accuracy study was conducted on adult patients with syncope, who presented to the emergency departments of Shohadaye Tajrish and Imam Hossein Hospitals in Tehran from March 2018 to March 2019. The data required for determining CSRS were collected during the initial assessment and the underlying etiology was confirmed through further diagnostic follow-up under the supervision of a cardiologist or neurologist. Finally, the screening performance characteristics of the score were calculated.

RESULTS: 300 patients with the mean age of 56.38 ± 19.10 years were studied. The source of syncope was cardiac in 133 (44.3%) and non-cardiac in 137 (55.7%) patients. The area under the ROC curve of CSRS in differentiating cardiac syncope was 0.77 (95% CI: 0.715-0.824). At a cutoff point of -1.5, the sensitivity and specificity of the score were calculated to be 73.68% (95% CI: 65.21-80.75%) and 73.05% (95%CI: 75.54-79.47%), respectively.

CONCLUSION: The present study reveals that CSRS has fair accuracy in differentiating the source of syncope and has no superiority over a clinical examination. Therefore, we do not recommend relying on the CSRS to differentiate between cardiac and non-cardiac syncope alone.