Is Cardiac Catheterization the Best Diagnostic Tool for Atherosclerosis Severity?
No, cardiac catheterization is not the best initial diagnostic tool for determining atherosclerosis severity—non-invasive imaging modalities including coronary CT angiography (CTA), stress imaging, and echocardiography are now the preferred first-line diagnostic approaches, with invasive catheterization reserved for specific situations where non-invasive testing is inconclusive, discordant with clinical findings, or when intervention is being considered. 1
Current Guideline-Based Diagnostic Approach
First-Line Non-Invasive Testing
The 2019 ESC Guidelines for Chronic Coronary Syndromes establish that non-invasive functional imaging for myocardial ischemia or coronary CTA is recommended as the initial test for diagnosing coronary artery disease (CAD) in symptomatic patients where obstructive CAD cannot be excluded by clinical assessment alone. 1 This represents a fundamental shift away from invasive catheterization as a primary diagnostic tool.
- Selection of the initial non-invasive test should be based on clinical likelihood of CAD, patient characteristics that influence test performance, local expertise, and test availability. 1
- Resting transthoracic echocardiography is recommended in all patients for exclusion of alternative causes of angina, identification of regional wall motion abnormalities suggestive of CAD, measurement of left ventricular ejection fraction for risk stratification, and evaluation of diastolic function. 1
When Cardiac Catheterization Is Appropriate
Invasive angiography is recommended as an alternative test only in patients with high clinical likelihood and severe symptoms refractory to medical therapy, or typical angina at a low level of exercise with clinical evaluation indicating high event risk. 1
The ACC/AHA guidelines specify that cardiac catheterization for evaluation is an effective diagnostic tool when results of Doppler echocardiography are equivocal regarding severity or when there is discrepancy between clinical and non-invasive findings. 1
Specific Clinical Scenarios for Catheterization
Valvular Disease Assessment
- Cardiac catheterization for hemodynamic evaluation should be performed for assessment of severity when non-invasive tests are inconclusive or when there is discrepancy between non-invasive tests and clinical findings. 1
- Diagnostic cardiac catheterization is NOT recommended to assess valve hemodynamics when 2D and Doppler echocardiographic data are concordant with clinical findings. 1
Pre-Surgical Evaluation
The ACR Appropriateness Criteria note that diagnostic catheterization is primarily used to resolve specific issues related to surgical intervention, including preoperative evaluation of coronary arteries, assessment of pulmonary vascular disease and its response to vasoactive agents, and evaluation for heart or heart/lung transplantation. 1
Complex Anatomy
Catheterization serves as an adjunct to non-invasive assessment of morphologic and/or functional characteristics of complex congenital heart disease, such as delineating arterial and venous anatomy in patients with heterotaxy or those who have had previous palliation. 1
Advantages of Non-Invasive Approaches
Superior Safety Profile
Cardiac catheterization carries definite morbidity (contrast reactions, renal failure, hematomas, arterial and venous injuries, radiation exposure) and a small but definite mortality, making it less desirable as a first-line diagnostic tool. 1
Diagnostic Accuracy of Alternatives
- Coronary CTA demonstrates 95% sensitivity, 83% specificity, 64% positive predictive value, and 99% negative predictive value for detection of CAD, suggesting high diagnostic accuracy for detecting coronary stenosis at thresholds of 50%. 1
- FFR-CT provides incremental improvement in accuracy over CTA alone (84% versus 59%), mitigating the high sensitivity/low specificity tradeoff of CTA and correctly reclassifying 68% of false-positive patients as true negatives. 1
Prognostic Information
The CONFIRM registry showed that patients with non-obstructive and obstructive CAD have incrementally higher rates of mortality, whereas absence of atherosclerosis is associated with very favorable prognosis—information uniquely available through coronary CTA that includes plaque burden assessment. 1
Critical Caveats and Common Pitfalls
Avoid Premature Catheterization
A major risk of routine cardiac catheterization is that premature or unnecessary revascularization procedures may be performed subsequently. 2 The clinician must obtain all necessary data, avoid unnecessary and repetitive tests, and interpret all data in proper context before proceeding to invasive evaluation.
Recognize When Catheterization Adds Value
Invasive functional assessment (FFR/iwFR) must be available and used to evaluate stenoses before revascularization, unless very high grade (>90% diameter stenosis). 1 This means that even when catheterization is performed, additional physiological assessment is typically required.
Don't Use Catheterization for Risk Stratification Alone
Invasive coronary angiography (ICA) is NOT recommended solely for risk stratification. 1 Risk stratification should preferably use stress imaging or coronary CTA, or alternatively exercise stress ECG if significant exercise can be performed and the ECG is amenable to identifying ischemic changes.
Algorithmic Approach to Diagnostic Testing
Begin with clinical assessment and resting echocardiography in all patients with suspected atherosclerosis 1
Proceed to non-invasive testing (coronary CTA or functional imaging for ischemia) based on clinical likelihood of CAD 1
Reserve cardiac catheterization for:
If catheterization is performed, include physiological assessment (FFR/iwFR) for stenoses that are not clearly severe 1