From the Guidelines
Coronary artery CT is indicated for intermediate-risk patients with acute chest pain and no known coronary artery disease (CAD) eligible for diagnostic testing after a negative or inconclusive evaluation for acute coronary syndrome (ACS), as it is useful for exclusion of atherosclerotic plaque and obstructive CAD 1. The primary indications for coronary artery CT include:
- Evaluation of patients with intermediate risk of coronary artery disease who present with chest pain or angina-like symptoms, particularly when other tests are inconclusive or contraindicated
- Patients with equivocal stress test results who need further assessment
- Evaluating patients with new-onset heart failure to determine if coronary artery disease is the underlying cause
- Assessment of coronary anomalies, evaluation of coronary artery bypass grafts and stents, preoperative assessment before non-cardiac surgery in selected patients, and screening in asymptomatic individuals with high risk factors The test is valuable because it provides detailed anatomical information about coronary arteries non-invasively, with high negative predictive value for excluding significant coronary stenosis 1. However, it does involve radiation exposure and requires administration of iodinated contrast, so it should be used judiciously in patients with kidney disease or contrast allergies 1. Some key considerations for the use of coronary artery CT include:
- A normal scan excludes CAD, with a high negative predictive value (NPV) to exclude ACS
- Severe calcifications (high calcium score) and elevated or irregular heart rate can limit the use of coronary artery CT
- The use of coronary artery CT in the acute setting in patients with stents or previous CABG has not been validated
- Computed tomography (CT) imaging can effectively exclude other causes of acute chest pain that, if untreated, are associated with high mortality, namely pulmonary embolism and aortic dissection 1. In summary, coronary artery CT is a useful diagnostic tool for evaluating coronary artery disease, particularly in intermediate-risk patients with acute chest pain and no known CAD, and should be used judiciously based on individual patient characteristics and clinical presentation 1.
From the Research
Indications for Coronary Artery CT
- Coronary artery CT is recommended for sorting patients presenting with stable or acute chest pain with low to intermediate risk of coronary artery disease (CAD) 2.
- It is useful for diagnosing CAD in high-risk patients, notably those with acute coronary syndrome (ACS) without ST-elevation 2.
- Coronary CT-scan represents a great opportunity for the screening of atherosclerosis in patients at risk and allows a better prevention of coronary artery disease by introduction of preventive treatments in patients with abnormal coronary CT-scan, especially statins 2.
- It is useful for the follow-up of patients who underwent a coronary arteries revascularization with either stents or bypasses 2.
Specific Uses of Coronary Artery CT
- Coronary CT angiography (CCTA) may play a role in higher risk patients, such as those evaluated in the emergency room with acute chest pain 3.
- CCTA may play a role in the risk stratification of selected intermediate-risk patients 3.
- Coronary artery CT is used to evaluate coronary artery disease and revascularization requirement before trans-catheter aortic valve replacement 4.
- It is used to identify CAD and revascularization requirement in patients with severe aortic stenosis considered for transcatheter aortic valve replacement (TAVR) 4.
Diagnostic Performance of Coronary Artery CT
- The diagnostic performance of CCTA in the low calcium score group was better than the high calcium score group (AUC 0.81 vs. 0.63) 4.
- CCTA had similar odd-ratios of 3.22 (1.26-8.23) in predicting revascularization 4.
- Coronary CT angiography has demonstrated its growing role to rule out significant CAD given its high negative predictive value 5.
Clinical Utility of Coronary Artery CT
- The use of coronary CT angiography in the emergency department represents a common, appropriate application of CTA in the community 6.
- Clinical practice guidelines that recommend the use of coronary CTA in the emergency department are warranted 6.
- Coronary CT-scan has become the Gold Standard exam before an aortic valve replacement, for the measurement of the aortic root notably, allowing the best prothesis selection 2.