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Not yet recruitingNCT05560126Updated Jul 31, 2025

Canadian Prehospital Syncope Risk Score (Prehospital CSRS)

An observational study in Syncope, sponsored by Venkatesh Thiruganasambandamoorthy. Not yet recruiting at 1 site in Canada. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-07-31.

Sponsored by Venkatesh Thiruganasambandamoorthy · Observational

Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
4,875
Ages
18 Years and older
Sex
All
01

Study summary

Background: Syncope is defined as a sudden, brief loss of consciousness (LOC) followed by a rapid complete recovery. It accounts for 160,000 emergency department (ED) visits each year in Canada. Despite this, few people are hospitalized (\~15%) and even fewer will die (\~1%). Two-thirds of patients with syncope arrive at the ED by calling 911. There are many causes of syncope. Identifying patients at low risk for bad outcomes would allow paramedics to safely determine which patients need care in the ED from those who can remain home. The research team recently developed the Canadian Prehospital Syncope Risk Score (CPSRS) which accurately identified patients at low risk for 30-day serious outcomes.

Objective: The goal of this study is to validate the accuracy of the CPSRS in the prehospital setting or refine if needed to predict the risk of 30-day serious outcomes for patients with syncope.

Methods: The research team will enroll patients with syncope from five paramedic services across Canada (British Columbia - Vancouver and Kelowna areas only, London-Middlesex, York Region, Frontenac, and Ottawa). The research team will exclude patients \<18 years old, LOC >5 minutes, changes in mental status from baseline, alcohol or drug intoxication, or language barrier. Paramedics will fill out a study data collection form with the CPSRS items and additional data should the tool need refinement. The data will be entered into a secure database and will assess patient outcomes (death and potentially life-threatening medical conditions) at 30 days. The research team will examine model accuracy using standard prediction measures and look to improve model accuracy if needed. The research team expects to enroll 4875 patients over a 1-year recruitment period based on annual call volumes.

Expected Outcomes: Once validated, the tool could reduce the number of patients transported to the hospital by identifying those at low risk. This would improve patient-oriented care, while at the same time saving valuable paramedic and ED resources.

Read the detailed description

The study will include patients from British Columbia (BC) Emergency Health Services (Vancouver and Kelowna areas only), London-Middlesex Paramedic Services - receiving hospitals: London Health Science Centre, York Region Paramedic Services - receiving hospital Markham Stouffville Hospital, Southlake Regional Health Centre, Mackenzie Health (Richmond Hill and Vaughan Hospital), Frontenac Paramedic Services - receiving hospitals: Kingston General Hospital, Hotel Dieu Hospital, and Ottawa Paramedic Services - receiving hospitals: The Ottawa Hospital (Civic and General campus), Queensway Carleton Hospital, Montfort Hospital.

Consecutive 911 patients will be screened by paramedics during their initial assessment. Patients meeting the above inclusion and exclusion criteria will be enrolled in the study. The research team will collect data for the CPSRS validation as well as additional variables for tool refinement if necessary. The additional variables were identified through literature, and experts in areas of syncope, prehospital, and emergency medicine. The research team will prospectively collect data in the prehospital setting, and through records review in both prehospital and in-hospital settings.

The research team will assess for outcome occurrence using a stepwise approach: 1) Review of prehospital records including ECG; 2) ED and inpatient hospital records during the index ED or any return ED visits including autopsy records for those who died, outpatient clinical notes and results of outpatient investigations available in the electronic medical records. 3) The research team will conduct a 30-day outcome assessment by telephone follow-up to verify that the patient is alive and has not sustained any SAE. During follow-up, The research team will ask questions regarding ED or outpatient clinic visits after the index event, any new diagnosis or procedural interventions, and if the cause for the syncope has been identified. The questions will require a yes/no answer. If the patient has difficulty comprehending the questions, the research team will assist the patient to understand the meaning of the questions. In addition to the questions for outcome assessment, the research team will ask patients their comfort with paramedics using the CPSRS to make disposition decisions. Our team has successfully used similar follow-up for outcomes in previous clinical decision rule studies. The research team will also work with Institute for Clinical Evaluative Sciences (ICES) or Population Data BC to check for deaths, return to ED, hospitalization, and device insertion for 1-year outcomes. Final determination of SAE will be completed by an independent Adjudication Committee blinded to the predictor variables comprised of three investigators (1 advanced care paramedic and 2 ED physicians).

The research team plans to complete the study over a twenty-one-month period which is highly feasible. The first three months are for study preparation, 12 months of data collection, and 3 months for data cleaning and analysis. The research team will publish and undertake end-of-grant knowledge translation (KT) activities during the last three months.

02

Conditions studied

  • Syncope

Keywords

  • Syncope
  • Emergency Medicine Services
  • Prehospital
  • Risk-stratification
  • Emergency Department
03

In context

Syncope

201 studies on the registry are indexed under Syncope; 36 are open to participants now.

This study's planned enrollment of 4,875 is above the median of 250 across 84 observational studies indexed under Syncope.

Browse Syncope studies →

Lead sponsor

This is the only study on the registry with Venkatesh Thiruganasambandamoorthy as lead sponsor.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No
Sampling method
Non-probability sample

Study population

Patients who access paramedic services through the 911 system will be included if they have suffered syncope, defined as a sudden transient loss of consciousness followed by spontaneous complete recovery.

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Patients who access paramedic services through the 911 system will be included if they have suffered syncope, defined as a sudden transient loss of consciousness followed by spontaneous complete recovery.

Exclusion criteria

Exclusion Criteria:

  • Pediatric patients (\<18 years old),
  • Patients who have a prolonged period of unconsciousness (>5 minutes),
  • Change in mental status from baseline, witnessed seizure,
  • Loss of consciousness due to head trauma (i.e., trauma was the initial event),
  • or if unable to provide accurate details due to language barrier, cognitive impairment, alcohol, or drug intoxication.
05

Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
4,875 participants (estimated)
Patient registry
No
06

What researchers measure

Primary outcomes

  1. A serious adverse event (SAE) occurring within 30 days of the 911 call

    The definition of SAE is consistent with our previous syncope research studies including the CPSRS derivation and comprises of any one of the following: a) Death due to a cause of syncope or an unknown cause; b) Arrhythmia; c) Myocardial infarction; d) Identification of serious structural heart disease; e) Aortic dissection; f) Pulmonary embolism; g) Severe pulmonary artery hypertension; h) Subarachnoid hemorrhage; i) Significant hemorrhage; j) Other serious conditions such as ectopic pregnancy, pneumothorax, or sepsis that will require treatment, or any intervention used to treat a cause of syncope.

    Time frame: 30 days after the 911 call

07

Study locations

1 site
08

References and documents

Individual participant data

Plan to share: No — We don't have no plan to share IPD

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jul 31, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05560126
Lead sponsor
Venkatesh Thiruganasambandamoorthy
Responsible party
Venkatesh Thiruganasambandamoorthy (Principal Investigator, Ottawa Hospital Research Institute) — Sponsor-investigator
First posted
Sep 29, 2022
Start date
Sep 1, 2025 (estimated)
Primary completion
Sep 30, 2027 (estimated)
Completion
Sep 30, 2027 (estimated)
Last update
Jul 31, 2025

Study contacts

Iris Nguyen, BSc
Contact
pnguyen@ohri.ca
613-798-5555 ext. 17766
Jane Park, BHSc
Contact
junpark@ohri.ca
613-798-5555 ext. 19347
Venkatesh Thiruganasambandamoorthy, CCFP-EM, MSc
principal investigator · Ottawa Hospital Research Institute

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is not yet recruiting, as verified in Mar 2025. You cannot join it, but the record below documents what was studied.

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