CT-Based Abdominal Aortic Calcium Score and CAD-RADS 2.0 in Elderly Chest Pain: A Cohort Study
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Enrollment
- 68
- Locations
- 1
- Primary Endpoint
- Image Analysis
Study Overview
Brief Summary
Background: Abdominal aortic calcium (AAC) is a marker of systemic atherosclerosis and may predict cardiovascular outcomes similarly to coronary artery calcium (CAC). This study evaluates the predictive efficacy of CT-based AAC scores for coronary plaque burden and stenosis using the CAD-RADS 2.0 classification system.
Methods: A prospective cohort of 68 patients (mean age 67.5 years) with chest pain underwent cardiac CT for CAC, AAC scoring, and coronary computed tomography angiography (CCTA) at Kaohsiung Chang Gung Memorial Hospital (June 2021-May 2023). AAC scores were quantified using the Agatston method across 8 cm and 5 cm aortic segments, and outcomes were analyzed based on CAD-RADS 2.0 and plaque burden classifications.
Detailed Description
Introduction Coronary artery calcium (CAC) scoring, developed and validated using computed tomography (CT), is a well-established technique for quantifying coronary atherosclerosis and assessing cardiovascular risk, thereby guiding preventive therapeutic strategies. Similarly, abdominal aortic calcium (AAC) is a biomarker indicating the degree of calcification within the abdominal aorta, reflecting systemic atherosclerosis. AAC has been shown to predict cardiovascular morbidity and mortality.
AAC can be assessed using two common methods: Kidney, Ureter, and Bladder (KUB) plain film radiography and CT. Studies have demonstrated a correlation between AAC and CAC scores, with AAC suggesting the presence of asymptomatic coronary artery disease (CAD). This highlights the potential importance of quantifying AAC in predicting CAD.
Coronary Computed Tomography Angiography (CCTA) enables direct visualization of coronary artery lumen stenosis, atherosclerotic plaque composition, and high-risk plaque features, such as low attenuation, spot calcification, positive remodeling, and the napkin ring sign. CCTA is particularly valuable in patients with stable chest pain, given its high sensitivity and specificity in detecting CAD. Furthermore, it plays a critical role in guiding decisions regarding coronary revascularization procedures. Beyond assessing coronary artery stenosis and atherosclerotic plaque characteristics, analyzing plaque volume and burden provides prognostic value in stratifying the risk of acute coronary syndrome (ACS) in patients with stable chest pain undergoing CCTA.
The Coronary Artery Disease Reporting and Data System (CAD-RADS) is a comprehensive framework designed to standardize the assessment of disease severity and guide treatment decisions in patients with CAD. Initially published in 2016, CAD-RADS employs a categorical system based on coronary artery stenosis and high-risk plaque characteristics as modifiers. The 2022 update, CAD-RADS 2.0, incorporates plaque burden as a new subclassification and assesses lesion-specific ischemia using CT fractional flow reserve (CT-FFR) or myocardial CT perfusion (CTP). CAD-RADS aims to standardize CCTA reporting and improve communication with referring physicians, including recommendations.
Previous studies have indicated a correlation between AAC and CAC, with AAC quantification linked to traditional cardiovascular risk factors and cardiovascular events. Additionally, CT-based AAC quantification can predict future cardiovascular events in asymptomatic adults. However, few studies have explored whether AAC correlates with non-calcified coronary artery plaques or the degree of coronary artery stenosis. This study aims to investigate the correlation between CT-based AAC scores and coronary plaque burden and stenosis, using the CAD-RADS 2.0 classification system.
Study Design
- Study Type
- Interventional
- Allocation
- Na
- Intervention Model
- Single Group
- Primary Purpose
- Diagnostic
- Masking
- None
Eligibility Criteria
- Ages
- 60 Years to — (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •patients with chest pain or discomfort who were scheduled to undergo cardiac CT for CAC and CCTA
- •determined by the treating physician for the evaluation of CAD
Exclusion Criteria
- •severe allergies to contrast agents
- •metallic implants in the lumbar spine
- •renal function abnormalities (estimated glomerular filtration rate [eGFR] < 60)
- •abdominal aortic aneurysms
- •prior coronary artery stent placements or bypass surgery
Arms & Interventions
CCTA and Non-Enhanced Abdominal CT Scan Protocol
CCTA was performed using a 640-slice multislice CT scanner (Canon Aquilion One Genesis, Canon Medical Systems, Japan). All participants received sublingual nitroglycerin (0.3 mg) to promote coronary vasodilation prior to imaging. The first phase involved an unenhanced, prospective electrocardiogram (ECG)-gated volume scan for CAC assessment, configured to 120 kVp and 50 mAs with a field of view (FOV) of 16 cm to ensure comprehensive cardiac coverage. Imaging was performed with a rotation time of 0.275 seconds and a slice thickness of 2 mm. Following this, an abdominal aorta scan was performed using a non-ECG-gated sequential scan mode, maintaining identical settings of 120 kVp and 2 mm slice thickness. The inferior aspect of the L5 vertebral body endplate was used as the caudal extent of the abdominal volume to be imaged, covering the iliac bifurcation of the infrarenal abdominal aorta while minimizing radiation exposure to the pelvic genital organs.
Intervention: CCTA (Diagnostic Test)
Outcomes
Primary Outcomes
Image Analysis
Time Frame: From enrollment to the end of treatment at 1 week
The CAD-RADS 2.0 classification system was used to assess the severity of coronary stenosis across five distinct categories: CAD-RADS 0 (no visible stenosis, 0% maximal coronary stenosis), CAD-RADS 1 (minimal stenosis, 1-24%), CAD-RADS 2 (mild stenosis, 25-49%), CAD-RADS 3 (moderate stenosis, 50-69%), CAD-RADS 4 (severe stenosis, subdivided into 4A \[70-99%\] and 4B \[left main \>50% or three-vessel obstructive disease\]), and CAD-RADS 5 (100% occlusion). The outcome measures in this study were categorized based on the 2022 Coronary Artery Disease-Reporting and Data System (CAD-RADS), which classifies coronary artery stenosis and plaque burden into distinct categories without the use of specific measurement units. Coronary artery stenosis was graded using a numeric scale from 0 to 5, with higher numbers indicating greater severity of stenosis. Plaque volume was categorized using a classification system ranging from P1 to P4, with P4 representing the highest plaque burden.
Secondary Outcomes
No secondary outcomes reported