Coronary CT Angiography (CCTA) and the role of structured reporting in contemporary CAD management

Introduction: Coronary Computed Tomography Angiography (CCTA) is a noninvasive, cost-effective, and rapid heart imaging test essential for the early and accurate detection, diagnosis, and risk stratification of Coronary Artery Disease (CAD). CCTA uses an intravenous injection of iodine-containing contrast material and CT scanning to determine if plaque buildup has narrowed the coronary arteries. CCTA is recommended for assessing patients presenting with acute chest pain (to exclude significant obstructive CAD) and in intermediate- to high-risk patients with stable chest pain.

Methods and Technique: To achieve diagnostic quality scans, technical and patient factors must be optimized. This typically involves pharmacological agents like beta-blockers to control the heart rate (if >65 BPM) and nitroglycerin to promote coronary vasodilation. Patient preparation requires avoiding caffeinated products and certain medications (e.g., Viagra or similar) and requires breath-holding during the scan to minimize motion artifacts. The resulting images provide greater detail of soft tissue and blood vessels than traditional X-rays, allowing visualization of internal organs, bone, and potential extracardiac findings (e.g., aortic abnormalities, pulmonary embolism).

Reporting and Clinical Relevance (CAD-RADS 2.0): Consistent and concise CCTA reporting is standardized using the Coronary Artery Disease–Reporting and Data System (CAD-RADS) 2.0. This structured system informs the overseeing cardiologist and serves as a reference for subsequent procedures, such as Invasive Coronary Angiography (ICA). CAD-RADS 2.0 classifies findings based on stenosis severity (0 to 5) and incorporates overall plaque burden (P1 to P4).

Crucially, the system utilizes several modifiers:

1. HRP (High-Risk Plaque): Added if two or more features—including low-attenuation plaque, positive remodeling, spotty calcification, or napkin-ring sign—are present. HRP is associated with an increased risk of acute coronary syndrome, independent of stenosis degree.
2. I (Ischemia): Used when non-invasive functional techniques (such as CT-FFR or stress CTP) define the hemodynamic significance of a stenosis (typically CAD-RADS 3 or 4A lesions).

Conclusion: CCTA is non-invasive and avoids the catheter placement complications and lengthy recovery time associated with ICA. By integrating detailed anatomical findings with assessments of plaque vulnerability (HRP) and functional significance (I), the standardized CAD-RADS 2.0 approach allows radiologists to provide crucial, actionable data, directly guiding cardiologists in determining appropriate patient management, particularly in determining whether ICA or functional assessment is the necessary next step for severe stenoses (CAD-RADS 4A/4B).

To be updated shortly..