Perfusion Imaging With Vasodilator Stress Echocardiography

Abstract

Cardiac stress testing with noninvasive imaging is increasingly used not only to detect the presence of coronary artery disease (CAD), but also to help to select appropriate therapy according to the extent and severity of disease. To that end, there have been continuous efforts to improve the performance of all forms of stress testing. For example, recent advances in stress radionuclide imaging, such as gated acquisition for regional function, iterative reconstruction processing, and the development of new tracers, have occurred with the goals of improving sensitivity, reducing artifacts, and reducing ionizing radiation dose. For stress echocardiography, the use of strain imaging derived from tissue Doppler echocardiography or speckle-tracking algorithms are being applied to improve the detection of subtle myocardial dysfunction during exercise or inotropic stress.1 In this issue of Circulation: Cardiovascular Imaging , Porter and colleagues2 evaluate the diagnostic accuracy of an approach that combines two advances in stress imaging that have not been paired previously: (1) myocardial perfusion imaging with myocardial contrast echocardiography (MCE) and (2) vasodilator stress with the adenosine A2a-receptor agonist regadenoson. Article see p 628 The use of MCE during stress to enhance detection of CAD is not a new concept. Based on several decades of clinical studies, we know that conventional exercise or dobutamine echocardiography will miss the presence of CAD in ≈1 of 5 patients, although this exact figure can be argued because trials vary according to the population studied (eg, pretest probability of disease, prevalence of multivessel disease) and the definition of disease (eg, >50% or >70% stenosis).3,4 The subjective nature by which wall thickening is interpreted has taken blame for the sensitivity of stress …