August 28th, 2011
Anatomical vs. Physiological Assessment of Coronary Artery Disease
Just as the great voleur Willie Sutton robbed banks because “that’s where the money is,” why don’t we just look for coronary artery disease (CAD) directly in the coronary arteries?
At the ESC meeting today in Paris, Bharati Shivalkar of Belgium reviewed the assessment of CAD utilizing coronary CT angiography (anatomical) vs. the usual standard of care, stress testing (physiological).
Several studies, including CT-STAT and ROMICAT, have demonstrated cost and time savings — as well as safety — using an initial strategy of coronary CT angiography (64-slice or better) in the emergency room for the evaluation of low- to medium-risk patients whose symptoms suggest acute coronary syndrome but who lack evidence of significant ECG changes or elevated biomarkers. Patients with a negative coronary CT angiography scan have nearly a 100% negative predictive value for significant CAD and may safely be discharged from the ER. Those with >70% stenosis should proceed to cardiac catheterization with a view toward revascularization. Those with intermediate findings may proceed to diagnostic stress testing.
A future study, PROSPECT, will compare coronary CT angiography with stress testing in patients admitted to the hospital with chest pain.
Barriers to the increased use of coronary CT angiography in the ER include radiation safety concerns (partially addressed by newer dose-reducing strategies) and availability of the technology and expertise. False-positive studies may also lead to unnecessary invasive angiography.
My view is that old habits die hard, and most clinicians are accustomed to the stress-testing algorithm even though this approach is often slow, expensive, and perhaps outdated for certain patient groups.