Am J Emerg Med. 2023 Jan;63:69-73. doi: 10.1016/j.ajem.2022.10.026. Epub 2022 Oct 21.
OBJECTIVE: This study aims to investigate the diagnostic value of End-tidal carbon dioxide (ETCO2) measured non-invasively at the bedside in order to distinguish between unstable angina pectoris (UAP) and non-cardiac chest pain among patients who present to the emergency department with chest pain without a history of cardiac pathology.
MATERIAL AND METHODS: This clinical study is a prospective case-control study among patients presenting to the emergency department of a tertiary hospital with chest pain. After evaluating the inclusion and exclusion criteria, the patients were divided into two groups: 62 patients with UAP and 62 patients with non-cardiac chest pain. Receiver Operating Characteristic (ROC) analysis was used to determine the cut-off in diagnostic value measurements. For UAP prediction, the odds ratio of ETCO2 (including 95% confidence intervals) was calculated using univariate with binary logistic regression analysis.
RESULTS: ETCO2 had an excellent diagnostic power in detecting UAP, with 35 cut-offs determined (AUC: 0.84, 95% Cl: 0.76-0.90, p < 0.001). When ETCO2, which affects both non-cardiac chest pain and UAP, is evaluated, an ETCO2 of <35 is statistically significant and 9.74 times more common among UAP patients than patients with non-cardiac chest pain.
CONCLUSION: ETCO2, a non-invasive parameter that can be measured immediately at the bedside, may be proposed as a potential biomarker for differentiating patients with UAP from those with non-cardiac chest pain.
PMID:36327752 | DOI:10.1016/j.ajem.2022.10.026