Our project identified that FOVUS scan results in emergency department patients with chest pain are associated with 30 day clinical outcomes.  However, we demonstrated that the test is not good enough to be used alone in the risk stratification of these patients.  Our results are supporting the development of new research into refining the ultrasound protocol in an effort to improve the predictive accuracy.  Our study has clarified that the FOVUS scan is not ready for clinical implementation as is, and has identified new research questions to be pursued by our team. We also learned important lessons about how to implement new ultrasound protocols in the emergency department, specifically around the areas of training, logistics and quality improvement.

Background and objective: Point-of-care focused vascular ultrasound (FOVUS), an assessment of carotid artery plaque, predicts coronary artery disease in outpatients referred for coronary angiography. Our primary objective was to determine the diagnostic accuracy of sonographer-performed FOVUS to predict major adverse cardiac events (MACE) within 30 days among patients with suspected cardiac ischemia in the emergency department (ED).

Methods: We conducted a prospective cohort study of patients with chest pain presenting to a tertiary care ED who had an electrocardiogram and cardiac troponin testing. The primary outcome was a composite of death, acute myocardial infarction, or re-vascularization at 30 days. A sonographer performed FOVUS scans in consenting eligible subjects. Emergency physicians, blinded to the sonographer FOVUS result, performed a second FOVUS on some subjects.

Results: We recruited 326 subjects (age 62.1 ± 13.5 years; 166 (52%) men), 319 of whom completed an FOVUS scan by the sonographer. Of these, 198 (62%) had a positive FOVUS scan and 41 (13%) had a 30-day MACE. The sensitivity was 83% (95% CI 71-94%), specificity 41% (95% CI 36-47%), positive-likelihood ratio 1.41 (95% CI 1.19-1.68), and negative-likelihood ratio 0.41 (95% CI 0.23-0.75). Among 71 subjects also scanned by an emergency physician, the Kappa was 0.50 (95% CI 0.31-0.70), suggesting moderate agreement between sonographer and emergency physician on the determination of significant carotid plaque.

Conclusions: The presence of carotid plaque on sonographer-performed FOVUS is associated with 30-day MACE in ED patients presenting with chest pain. The prognostic performance of FOVUS is not sufficient to support its use as a stand-alone risk stratification tool in the ED. Future work should investigate FOVUS in conjunction with validated clinical decision rules for chest pain and the impact of enhanced training and quality improvement in the conduct of FOVUS by emergency physicians.

Registration: This study was registered at clinicaltrials.gov (NCT02947360).

Keywords: Cardiovascular disease; Cardiovascular imaging; Cardiovascular risk; Carotid artery; Carotid ultrasound; Emergency department; POCUS; Peripheral arterial disease; Ultrasound.

Hétu MF, SC Brooks, Chan W, Herr EJ, Sivilotti MLA, O’Callaghan N, Latiu V, Newbigging J, Norman PA, Day AG, Hill B, Johri AM (2023) HEART+ Score: Integrating Bedside Carotid Ultrasound to Chest pain Assessment in the Emergency Department. Canadian Journal of Emergency Medicine. 2023 (under review)

SC Brooks, Sivilotti MLA, Hétu MF, Norman PA, Day AG, O’Callaghan N, Latiu V, Newbigging J, Hill B, Johri AM (2023). Focused carotid ultrasound to predict major adverse cardiac events among emergency department patients with chest pain. Canadian Journal of Emergency Medicine. 2023;25(1): 81–89.

Chan W, Hétu MF, Herr JE, Brooks S, O’Callaghan N, Liblik D, Johri AM (2019) IntelliPlaque: A Novel, Automated Grayscale Analysis of Carotid Artery Plaque to Predict Risk in Patients Presenting to the Emergency Department with Chest Pain. American Society of Echocardiography Scientific Session, Portland, Oregon, USA. June. Journal of the American Society of Echocardiography.2022;32(6):B107.