About the project
Acute chest pain is a frequent presenting symptom in emergency primary care. In most cases, the symptoms are caused by a benign, low-risk illness. However, accurate exclusion of acute myocardial infarction (AMI) AMI outside of the hospital is challenging due to less sensitive diagnostic decision aids. The following diagnostic uncertainty contributes to defensive medicine, high hospital referral rates, crowding of low-risk patients in the emergency departments, and increased costs.
Objectives
The project's main objective was to explore whether a diagnostic one-hour algorithm for interpreting high-sensitivity troponin T measurements would enhance the assessment of low-risk patients with chest pain in emergency primary care.
The project also aimed to compare the diagnostic rule-out ability of a single hs-cTnT measurement to the HEART score and to evaluate the cost-effectiveness of assessing low-risk patients in emergency primary care compared to routine hospital management.
Outcomes
The prospective, observational diagnostic OUT-ACS study was conducted at the Oslo Accident and Emergency Outpatient Clinic (OAEOC) in Oslo, Norway. During the enrollment period (Nov. 2016 - Oct. 2018), 1711 patients with acute, non-traumatic chest pain were included. Patients in need of further tests but not immediate hospitalisation were offered prehospital hs-cTnT sampling at the clinic, collected at 0, 1 and 4 hours (control sample) from all participants.
AMI was the final diagnosis in 3.6 % (n=61) of the patients. A total of 76.6 % (1311/1711) had an AMI ruled out by the 0/1-hour algorithm with high diagnostic safety (sensitivity 98.4 %, negative predictive value 99.9 %). The rule-out group also had very few events of AMI and all-cause death the following 90 days (0.3 %).
In the case of a single hs-cTnT measurement, the single troponin strategy was superior to the HEART score (sensitivity 100 % and 91.8 %, respectively). The OUT-ACS approach was also considered highly cost-effective, with an estimated cost reduction of €-1794 and a mean decrease in length of stay of 18.9 hours compared to routine hospital management.
Background
The project is run by former PhD candidate Tonje R. Johannessen at the Department of General Practice at the Institute of Health and Society, UiO. The project collaborates with the Myocardial Ischemia research group at the Department of Cardiology, Oslo University Hospital Ullevaal, and Oslo Accident and Emergency Outpatient Clinic (City of Oslo Health Agency).
The project was initiated in January 2016, with a patient enrollment period from 2016 to 2018. The project was expanded to a PhD project in 2018 and completed in November 2022.
The OUT-ACS project has received an extended project period due to ongoing sub-projects.
Sub-projects
- International meta-analysis (Taiwan), collaboration (completed, ref: https://www.acpjournals.org/doi/10.7326/M21-1499)
- OUT-ACS implementation study (active)
- ARTEMIS project (Germany), collaboration (active)
- Chest pain project (OUT-ACS + TRACE study/The Netherlands) (active)
Financing
- The Norwegian Research Fund for General Practice
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The Norwegian Committee on Research in General Practice
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The Norwegian Medical Association's Fund for Quality Improvement and Patient Safety
Project start and finish:
January 2016 – December 2026