Optimizing indications and diagnostic performance of computed tomography angiography in acute gastrointestinal
Hye Kyung Hyun1, Nak-Hoon Son2, Da Hyun Jung3
1Department of Internal Medicine, Yongin Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea.
Insights
Computed tomography angiography (CTA) has low accuracy for acute gastrointestinal (GI) bleeding. A clinical prediction model can guide selective CTA use, improving diagnostic yield and reducing inappropriate testing for GI bleeding patients.
Area of Science:
- Gastroenterology
- Radiology
- Medical Diagnostics
Background:
- Diagnostic accuracy of computed tomography angiography (CTA) for acute gastrointestinal (GI) bleeding is unclear.
- Optimal clinical indications for CTA in GI bleeding require further definition.
Purpose of the Study:
- Assess the diagnostic performance of CTA in patients with acute GI bleeding.
- Identify clinical predictors to establish optimal indications for CTA in acute GI bleeding.
Main Methods:
- Large cohort study of 1,770 patients undergoing CTA for suspected acute GI bleeding.
- Assessed sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CTA.
- Developed and validated a predictive nomogram using multivariate analysis of clinical predictors.
Main Results:
- CTA showed low sensitivity (44.9%) and PPV (52.4%), but high specificity (88.3%) and NPV (84.9%).
- Predictors of positive CTA included male sex, antithrombotics, low hemoglobin, elevated BUN, hemodynamic instability, hematemesis, and hematochezia.
- Selective CTA application based on a clinical risk model improved diagnostic sensitivity.
Conclusions:
- CTA is not ideal as an initial test for acute GI bleeding.
- A clinical prediction model can guide selective CTA use, improving diagnostic yield and reducing inappropriate testing.
Background And Aims:
The diagnostic accuracy of computed tomography angiography (CTA) and its appropriate clinical indications remain unclear. We aimed to assess the diagnostic performance of CTA and identify clinical predictors to determine the optimal clinical indications for its use in patients with acute gastrointestinal (GI) bleeding.
Methods:
This large cohort study included patients who underwent CTA for suspected acute GI bleeding in Korea between October 2011 and December 2023. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CTA were assessed. Multivariate analysis was conducted to identify the predictors of positive CTA findings, and a predictive nomogram was developed and validated.
Results:
Of the 5525 patients identified, 1770 were included in the final analysis. CTA demonstrated low sensitivity (44.9%) and PPV (52.4%), with relatively high specificity (88.3%) and NPV (84.9%). Multivariate analysis identified male sex, use of antithrombotic agents, low hemoglobin level (<9.6 g/dL), elevated blood urea nitrogen level (≥29.9 mg/dL), hemodynamic instability, and presentation with hematemesis or hematochezia as independent predictors of positive CTA findings. A nomogram incorporating these variables showed good discrimination. The selective application of CTA based on clinical risk factors improved diagnostic sensitivity (47.3% at predicted probability ≥0.1, 56.5% at ≥0.2, and 69.5% at ≥0.3; all P < .05).
Conclusions:
Although CTA may be unsuitable as an initial diagnostic modality for acute GI bleeding, its selective use-guided by a clinical prediction model-can help identify patients most likely to benefit, thereby reducing inappropriate use and improving the diagnostic yield of CTA.
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