From the Guidelines
Invasive coronary angiogram can be performed electively without first doing a CTCA or ischemia tests in specific high-risk scenarios, such as patients with typical angina symptoms and multiple risk factors, or those with known severe coronary artery disease requiring reassessment. These indications are based on the latest guidelines, including the 2019 European Heart Journal guidelines on chronic coronary syndromes 1, which recommend invasive coronary angiography (ICA) complemented by invasive physiological guidance for patients on medical treatment with a high event risk and revascularization considered for improvement of prognosis. The decision to proceed with invasive angiography without prior non-invasive testing should be based on individual patient risk factors, symptoms, and the potential benefits of immediate diagnostic clarity for treatment planning, as outlined in the 2014 ACC/AHA/AATS/PCNA/SCAI/STS focused update on the diagnosis and management of patients with stable ischemic heart disease 1. Key considerations include:
- Patients with high pre-test probability of coronary artery disease
- Known severe coronary artery disease requiring reassessment
- Previous coronary interventions needing evaluation for restenosis
- Contraindications to non-invasive testing
- Left main coronary artery disease suspicion
- Heart failure of unknown etiology
- Evaluation for cardiac surgery In these scenarios, the diagnostic accuracy of invasive angiography provides definitive information that can immediately guide intervention decisions, potentially avoiding delays in treatment and reducing the overall testing burden on patients who would likely need catheterization regardless of non-invasive test results.
From the Research
Indications for Invasive Coronary Angiogram without Prior CTCA or Ischaemia Tests
- There are specific clinical contexts where an invasive coronary angiogram may be performed electively without first doing a CTCA or ischaemia tests, as noted in studies 2, 3.
- In patients with acute coronary syndrome, coronary angiography may not always detect the cause of myocardial ischemia, and additional diagnostic procedures like intravascular ultrasound (IVUS) or the assessment of intracoronary physiological parameters may be necessary 3.
- For patients with previous coronary artery bypass grafting, computed tomography cardiac angiography (CTCA) before invasive coronary angiography (ICA) can lead to reductions in procedure time and contrast-induced nephropathy, with improved patient satisfaction 4.
- The diagnostic value of coronary CT angiography in comparison with invasive coronary angiography and intravascular ultrasound in patients with intermediate coronary artery stenosis has been evaluated, showing that anatomical criteria for the diagnosis of ischaemia differ by non-invasive and invasive methods 5.
Clinical Contexts and Diagnostic Procedures
- Invasive coronary angiography may be performed in clinical contexts different from stable angina, where techniques like fractional flow reserve (FFR) and instantaneous free wave ratio (iFR) have been validated 2.
- CTCA has shown great technological improvements and can provide a complete assessment of coronary artery disease, including anatomy, functionality, and plaque composition 6.
- The use of CTCA before ICA can facilitate the procedure and reduce complications in patients with previous coronary artery bypass grafting 4.
- The diagnostic performance of CTCA in assessing lesion severity and ischaemia has been compared to invasive methods, showing that CTCA presents overestimation in assessing lesion severity and lower diagnostic performance in assessing ischaemia 5.