When to order Computed Tomography Angiography (CTA) of the coronaries?

From the Guidelines

CTA coronaries should be ordered for patients with low to intermediate risk of coronary artery disease who need evaluation for suspected coronary artery disease, as it provides high diagnostic accuracy for detecting coronary stenosis and can help guide treatment decisions 1.

Key Indications for CTA Coronaries

• Evaluation of patients with chronic chest pain and high probability of coronary artery disease, as it has been shown to result in a significantly lower rate of death from coronary heart disease or nonfatal myocardial infarction at 5 years compared with standard of care alone 1
• Patients with atypical chest pain, equivocal stress test results, or when traditional stress testing is contraindicated
• Specific indications include evaluation of coronary anomalies, assessment before non-coronary cardiac surgery, and evaluation of coronary stents or bypass grafts

Contraindications and Precautions

• Patients with known severe coronary calcification, irregular heart rhythms, or inability to hold breath, as these factors reduce image quality
• Patients should have adequate renal function (GFR >30 mL/min) due to the need for iodinated contrast

Preparation and Procedure

• Before the procedure, patients may need beta-blockers to lower heart rate (target <65 bpm), and sublingual nitroglycerin is often administered to dilate coronary arteries for better visualization
• The test provides excellent negative predictive value, meaning a normal scan effectively rules out significant coronary disease, but positive findings may require confirmation with invasive coronary angiography, especially for determining the functional significance of stenoses 1

Clinical Decision-Making

• For intermediate-risk patients with acute chest pain and no known CAD, CCTA is useful for exclusion of atherosclerotic plaque and obstructive CAD, and can be used to guide decision-making regarding the use of coronary revascularization 1
• Fractional flow reserve computed tomography (FFR-CT) can be useful for the diagnosis of vessel-specific ischemia and to guide decision-making regarding the use of coronary revascularization in patients with coronary artery stenosis of 40% to 90% in a proximal or middle coronary artery on CCTA 1

From the FDA Drug Label

Iodixanol 320 mg Iodine/mL for CCTA was evaluated in two prospective, multicenter clinical studies in a total of 1106 adult patients. The patient population consisted of stable outpatients with chest pain or other symptoms suggestive of coronary artery disease, and no known history of coronary disease (320 mg Iodine/mL) coronary computed tomography angiography (CCTA) to assist in the diagnostic evaluation of patients with suspected coronary artery disease.

Order Computed Tomography Angiography (CTA) of the coronaries in patients with:

• Chest pain
• Other symptoms suggestive of coronary artery disease
• No known history of coronary disease 2 2

From the Research

Indications for Computed Tomography Angiography (CTA) of the Coronaries

• CTA of the coronaries is indicated in patients with suspected stable coronary artery disease, as it has been shown to reduce the annual rate of myocardial infarction compared to usual care 3.
• In the emergency department, CTA can be used to safely and rapidly triage patients with acute chest pain, particularly those with low-to-intermediate pretest probability of coronary artery disease 4, 5.
• The diagnostic performance of CTA is accurate when the clinical pretest probability of obstructive CAD is between 7% and 67% 6.

Patient Selection

• Patients with stable chest pain and a clinical indication for coronary angiography due to suspected CAD are suitable candidates for CTA 6.
• CTA can be used in patients with a low-to-intermediate pretest probability of coronary artery disease, as it has been shown to be safe and effective in this population 5.
• The diagnostic performance of CTA may be slightly lower in women and older patients (>75 years) 6.

Best Practice

• The safe practice of CT coronary angiography in adult patients requires guidance on best practice, including the use of heart rate controlling medication and minimizing radiation doses 7.
• Departments performing CTA should follow established standards of practice, such as those published by the Royal College of Radiologists (RCR) 7.