The Canadian Syncope Risk Score (CSRS) was developed to predict 30-day serious outcomes not evident during emergency department evaluation but has not been validated broadly. This article examines the performance of the CSRS in predicting serious clinical outcomes at 30 and 720 days among more than 2200 patients aged 40 years or older presenting with symptoms of syncope to the emergency departments in 8 countries spanning 3 continents.
Abstract
Background:
The Canadian Syncope Risk Score (CSRS) was developed to predict 30-day serious outcomes not evident during emergency department (ED) evaluation.
Objective:
To externally validate the CSRS and compare it with another validated score, the Osservatorio Epidemiologico della Sincope nel Lazio (OESIL) score.
Design:
Prospective cohort study.
Setting:
Large, international, multicenter study recruiting patients in EDs in 8 countries on 3 continents.
Participants:
Patients with syncope aged 40 years or older presenting to the ED within 12 hours of syncope.
Measurements:
Composite outcome of serious clinical plus procedural events (primary outcome) and the primary composite outcome excluding procedural interventions (secondary outcome).
Results:
Among 2283 patients with a mean age of 68 years, the primary composite outcome occurred in 7.2%, and the composite outcome excluding procedural interventions occurred in 3.1% at 30 days. Prognostic performance of the CSRS was good for both 30-day composite outcomes and better compared with the OESIL score (area under the receiver-operating characteristic curve [AUC], 0.85 [95% CI, 0.83 to 0.88] vs. 0.74 [CI, 0.71 to 0.78] and 0.80 [CI, 0.75 to 0.84] vs. 0.69 [CI, 0.64 to 0.75], respectively). Safety of triage, as measured by the frequency of the primary composite outcome in the low-risk group, was higher using the CSRS (19 of 1388 [0.6%]) versus the OESIL score (17 of 1104 [1.5%]). A simplified model including only the clinician classification of syncope (cardiac syncope, vasovagal syncope, or other) variable at ED discharge—a component of the CSRS—achieved similar discrimination as the CSRS (AUC, 0.83 [CI, 0.80 to 0.87] for the primary composite outcome).
Limitation:
Unable to disentangle the influence of other CSRS components on clinician classification of syncope at ED discharge.
Conclusion:
This international external validation of the CSRS showed good performance in identifying patients at low risk for serious outcomes outside of Canada and superior performance compared with the OESIL score. However, clinician classification of syncope at ED discharge seems to explain much of the performance of the CSRS in this study. The clinical utility of the CSRS remains uncertain.
Primary Funding Source:
Swiss National Science Foundation & Swiss Heart Foundation.
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Author, Article, and Disclosure Information
Tobias Zimmermann,
Cardiovascular Research Institute Basel (CRIB), Department of Cardiology, and Department of Intensive Care Medicine, University Hospital Basel, University of Basel, Basel, Switzerland, and GREAT Network, Rome, Italy (T.Z.)
Cardiovascular Research Institute Basel (CRIB) and Department of Cardiology, University Hospital Basel, University of Basel, Basel, Switzerland, and GREAT Network, Rome, Italy (J.F.L., P.L., P.B., S.S., I.S., M.D., M.K., C.M.)
Cardiovascular Research Institute Basel (CRIB) and Department of Cardiology, University Hospital Basel, University of Basel, Basel, Switzerland, GREAT Network, Rome, Italy, and Division of Cardiology, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada (T.N.)
Cardiovascular Research Institute Basel (CRIB) and Department of Cardiology, University Hospital Basel, University of Basel, Basel, Switzerland, GREAT Network, Rome, Italy, and Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil (D.M.G.)
Cardiovascular Research Institute Basel (CRIB) and Department of Cardiology, University Hospital Basel, University of Basel, Basel, Switzerland (V.W., N.G.)
GREAT Network, Rome, Italy, and Hospital Clinic, Barcelona, Catalonia, Spain (Ò.M.)
GREAT Network, Rome, Italy, and Kantonsspital Luzern, Luzern, Switzerland (M.C.)
GREAT Network, Rome, Italy, and Royal Brisbane & Women's Hospital, Herston, Australia (L.C.)
GREAT Network, Rome, Italy, and Christchurch Hospital, Christchurch, New Zealand (M.T.)
GREAT Network, Rome, Italy, and Servicio de Urgencias, Hospital Clínico San Carlos, Madrid, Spain (F.J.M.)
GREAT Network, Rome, Italy, and Emergency Medicine, Department of Medical-Surgery Sciences and Translational Medicine, University Sapienza Rome, Sant’Andrea Hospital, Italy (S.D.S.)
GREAT Network, Rome, Italy, and Baylor College of Medicine, Department of Emergency Medicine, Houston, Texas (W.F.P.)
Emergency Department, University Hospital Zürich, Zürich, Switzerland (D.I.K.)
Department of Orthopedics and Traumatology, University Hospital Basel, University of Basel, Basel, Switzerland (M.B.)
Instituto Cardiovascular de Buenos Aires, Buenos Aires, Argentina (J.P.C.)
Cardiovascular Research Institute Basel (CRIB), Department of Cardiology, and Department of Internal Medicine, University Hospital Basel, University of Basel, Basel, Switzerland, and GREAT Network, Rome, Italy (T.B.)
Department of Emergency Medicine, School of Epidemiology and Public Health, University of Ottawa, Ontario, Canada (V.T.).
Acknowledgment: The authors thank the patients who participated in the study and the emergency department staff and laboratory technicians of all participating sites for their most valuable efforts.
Grant Support: By research grants from the Swiss National Science Foundation, the Swiss Heart Foundation, the University of Basel (Switzerland), Abbott, B·R·A·H·M·S, Singulex, Roche, the University Hospital Basel (Switzerland), the Emergency Medicine Foundation (Australia), and the Emergency Care Foundation (New Zealand).
Disclosures: Disclosures can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M21-2313.
Reproducible Research Statement: Study protocol: Not available. Statistical code: Available on reasonable request from Dr. Mueller (e-mail, christian.
Corresponding Author: Christian Mueller, MD, CRIB and Department of Cardiology, University Hospital Basel, Petersgraben 4, CH-4031 Basel, Switzerland; e-mail, christian.
Author Contributions: Conception and design: J.P. Costabel, L. Cullen, S. Di Somma, J. du Fay de Lavallaz, C. Mueller, T. Nestelberger, V. Thiruganasambandamoorthy, T. Zimmermann.
Analysis and interpretation of the data: M. Christ, L. Cullen, J. du Fay de Lavallaz, D.M. Gualandro, P. Lopez-Ayala, C. Mueller, T. Nestelberger, W.F. Peacock, V. Thiruganasambandamoorthy, V. Widmer, T. Zimmermann.
Drafting of the article: J.P. Costabel, S. Di Somma, M. Diebold, J. du Fay de Lavallaz, C. Mueller, V. Thiruganasambandamoorthy, T. Zimmermann.
Critical revision of the article for important intellectual content: P. Badertscher, T. Breidthardt, M. Christ, J.P. Costabel, L. Cullen, M. Diebold, J. du Fay de Lavallaz, N. Glarner, D.M. Gualandro, M. Kühne, P. Lopez-Ayala, F.J. Martín-Sánchez, Ò. Miró, C. Mueller, T. Nestelberger, W.F. Peacock, S. Shrestha, I. Strebel, M. Than, V. Thiruganasambandamoorthy, T. Zimmermann.
Final approval of the article: P. Badertscher, M. Bilici, T. Breidthardt, M. Christ, J.P. Costabel, L. Cullen, S. Di Somma, M. Diebold, J. du Fay de Lavallaz, N. Glarner, D.M. Gualandro, D.I. Keller, M. Kühne, P. Lopez-Ayala, F.J. Martín-Sánchez, Ò. Miró, C. Mueller, T. Nestelberger, W.F. Peacock, S. Shrestha, I. Strebel, M. Than, V. Thiruganasambandamoorthy, V. Widmer, T. Zimmermann.
Provision of study materials or patients: T. Breidthardt, M. Christ, L. Cullen, J. du Fay de Lavallaz, M. Kühne, Ò. Miró, C. Mueller.
Statistical expertise: M. Christ, J. du Fay de Lavallaz, P. Lopez-Ayala, C. Mueller, I. Strebel, V. Thiruganasambandamoorthy, T. Zimmermann.
Obtaining of funding: L. Cullen, J. du Fay de Lavallaz, M. Kühne, C. Mueller.
Administrative, technical, or logistic support: M. Bilici, M. Christ, J. du Fay de Lavallaz, M. Kühne, C. Mueller, T. Nestelberger, T. Zimmermann.
Collection and assembly of data: P. Badertscher, T. Breidthardt, M. Christ, J.P. Costabel, S. Di Somma, J. du Fay de Lavallaz, D.M. Gualandro, D.I. Keller, P. Lopez-Ayala, F.J. Martín-Sánchez, Ò. Miró, C. Mueller, T. Nestelberger, W.F. Peacock, S. Shrestha, I. Strebel, V. Widmer, T. Zimmermann.
This article was published at Annals.org on 26 April 2022.
* Drs. Zimmermann and du Fay de Lavallaz contributed equally to this work and should be considered first authors.
† For members of the BASEL IX Investigators, see the Appendix.
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