Diagnosis and risk stratification in coronary artery disease: nuclear cardiology versus stress echocardiography

Abstract

Both myocardial perfusion imaging and stress echocardiographic techniques have evolved tremendously during the past decade and now play a major role in the evaluation and management of patients with known or suspected coronary artery disease (CAD). Each method requires clinical experience and technical expertise, and each has potential advantages and disadvantages that, in a given institution or practice setting, may make one or the other perform more accurately, more efficiently, or more cost-effectively. Stress echocardiography offers a relatively cost-effective method for cardiac imaging, and this technique is often viewed as a lower-cost alternative to myocardial perfusion imaging. The available data reported in the literature indicate that stress echocardiography and myocardial perfusion imaging provide comparable results for the diagnosis of CAD. However, in many situations the presence or absence of CAD is less important than determining the extent and severity of disease and identifying patient subgroups at high risk and low risk. From this perspective, myocardial perfusion imaging provides greater sensitivity than stress echocardiography for detecting the presence and extent of ischemic, jeopardized myocardium and for identifying viable yet dysfunctional myocardium. This greater sensitivity translates into more reliable prognostic information than that provided by stress echocardiography. This ability to predict which patients are at risk of subsequent cardiac events, and which are at extremely low risk and can be followed safely without further evaluation, may reduce the long-term costs of treating CAD, even though the short-term costs of stress echocardiography may be lower.