Stuart T. Higano

Physiological Assessment of Coronary Artery Disease in the Cardiac Catheterization Laboratory A Scientific Statement From the American Heart Association Committee on Diagnostic and Interventional Cardiac Catheterization, Council on Clinical Cardiology

With advances in technology, the physiological assessment of coronary artery disease in patients in the catheterization laboratory has become increasingly important in both clinical and research applications, but this assessment has evolved without standard nomenclature or techniques of data acquisition and measurement. Some questions regarding the interpretation, application, and outcome related to the results also remain unanswered. Accordingly, this consensus statement was designed to provide the background and evidence about physiological measurements and to describe standard methods for data acquisition and interpretation. The most common uses and support data from numerous clinical studies for the physiological assessment of coronary artery disease in the cardiac catheterization laboratory are reviewed. The goal of this statement is to provide a logical approach to the use of coronary physiological measurements in the catheterization lab to assist both clinicians and investigators in improving patient care.

Use of Intracoronary Ultrasound Imaging for Assessing Left Main Coronary Artery Disease

Coronary angiography has many limitations for the assessment of coronary artery disease. Intracoronary ultrasound imaging may overcome some of these limitations by providing direct visualization of the luminal area and plaque morphologic features. Although the size of the currently available intracoronary ultrasound catheters precludes their use in many diseased coronary vessels, lesions in the relatively large vessels, such as the left main coronary artery, can be readily assessed. Intracoronary ultrasound imaging was performed in five patients in whom the status of the left main coronary artery was unclear after conventional coronary angiography. Qualitative assessment of atherosclerotic involvement and quantitative analysis of the absolute luminal area and the percentage of area of stenosis were performed. No complications were associated with the intracoronary ultrasound procedure. In all five patients, the ultrasound studies provided additional information on which a clinical decision could be made. Intracoronary ultrasound imaging is useful for assessing disease of the left main coronary artery in selected patients in whom current angiographic techniques have provided equivocal results.

Diagnosis of Constrictive Pericarditis

To The Editor: The interesting case featured in “Images in Cardiovascular Medicine” in the March 3, 1998, issue of Circulation 1 illustrates how elusive the diagnosis of constrictive pericarditis can be and demonstrates how important it is to perform a comprehensive 2-dimensional/Doppler echocardiographic examination on all patients referred to the echocardiography laboratory. In patients with symptoms and signs of congestive heart failure, it does not suffice to simply report on the systolic function of the left and right ventricles. Comprehensive evaluation should include …

Pulse transmission coefficient: a novel nonhyperemic index for physiologic assessment of procedural success following percutaneous coronary interventions

Intracoronary pressure measurements and the determination of fractional flow reserve (FFR) after percutaneous coronary intervention (PCI) predict adverse events. Coronary lesions may impair the transmission of pressure waves across a stenosis, potentially acting as a high-frequency filter. The pulse transmission coefficient (PTC) is a nonhyperemic parameter that calculates the transmission of high-frequency components of the pressure signal through a stenosis. It was shown recently that PTC is highly correlated with FFR. This study was designed to examine the change of PTC as compared to FFR following PCI. Pressure signals were obtained by pressure guidewire in 27 lesions pre- and post-PCI and were analyzed with an algorithm that identifies the high-frequency component in the pressure signal. The PTC was calculated at baseline as the ratio between distal and proximal high-frequency components of the pressure waveform across the lesion. FFR measurements were assessed with intracoronary adenosine. There was a significant increase in PTC following PCI (0.15 +/- 0.17 at baseline vs. 0.84 +/- 0.11 post-PCI; P < 0.001). Comparable changes were observed for FFR (0.58 +/- 0.12 at baseline vs. 0.91 +/- 0.05 post-PCI; P < 0.001). PTC is a nonhyperemic parameter for physiologic assessment of coronary artery stenoses. Similar to FFR, PTC is significantly increased following PCI. Thus, it may serve as an adjunct index for the functional assessment of procedural success following PCI.