What are the advantages and disadvantages of coronary CTA versus catheter angiography?
Coronary CTA is less invasive than catheter angiography and avoids the potential complications of groin hematoma, pseudoaneurysm, retroperitoneal hematoma, dissection, and sedation-related complications. In addition to showing the lumen of the vessel, coronary CTA depicts the vessel wall and plaque or other pathology within it ( Figure 14-2 ), which can only be inferred from catheter angiography. Analysis of plaque composition is also possible. Coronary CTA shows anatomic abnormalities such as aberrant course or origin of the arteries ( Figure 14-3 ) and coronary artery fistulas, both of which are difficult to evaluate at catheterization. Coronary CTA depicts bypass grafts easily ( Figure 14-4 )—another challenge for catheter angiography. Coronary CTA also depicts other causes of chest pain, such as pulmonary embolus, aortic dissection, or pneumonia. In the presence of a coronary artery stent ( Figure 14-5 ), stent patency versus obstruction is usually determinable by CTA, although evaluation of the degree of patency or extent of in-stent stenosis is limited by beam hardening artifact from the stent. The presence of a very large amount of coronary calcium also complicates the evaluation of the degree of stenosis. Catheter angiography also permits diagnosis and intervention in one procedure, and in a patient for whom intervention is considered a likely outcome of the diagnostic procedure, catheter angiography should be used