Assessing the Physiologic Significance of Coronary Artery Disease: Role of Doppler Methodology

It is important to define both anatomic and functional significance of coronary artery stenoses. Quantitative angiography has decreased the inter- and intraobserver variability in interpreting the coronary angiogram, but it is less clinically applicable in assessing functional significance. The coronary Doppler catheter and guidewire can provide considerable information regarding the functional effects and pathophysiology of coronary stenosis in humans at the time of cardiac catheterization. Clinically, it is a simple and safe technique which makes it feasible in a clinical setting to use it as a tool to assess the physiologic significance of an intermediate stenosis or the functional result of an interventional procedure. Other uses for the intravascular Doppler method, such as the evaluation of cardiac transplant vasculopathy and rejection and evaluation of patients with chest pain syndromes and normal coronary angiograms, are being studied. However, the usefulness of this technique in decision-making has yet to be fully clarified. Future clinical studies should be directed toward comparing this method with noninvasive methods, that is, exercise treadmill test and thallium studies, and attempt to answer questions regarding its prognostic value.