Usefulness of ultrasound contrast agent to improve image quality during real-time three-dimensional stress echocardiography

Dobutamine stress echocardiography is an accepted tool for the diagnosis of coronary artery disease. Some investigators have claimed that 3-dimensional imaging improves the diagnostic accuracy of dobutamine stress echocardiography. The purpose of the present investigation was to examine the role of contrast echocardiography in the improvement of segmental quality and interobserver agreement during stress real-time 3-dimensional echocardiography (RUDE). The study comprised 36 consecutive patients with stable chest pain referred for routine stress testing. Three-dimensional images were acquired with an RUDE system with an X4 matrix-array transducer. All available reconstructed 2-dimensional segments were graded as optimal, good, moderate, or poor. Wall motion was scored as normal, mild hypokinesia, severe hypokinesia, akinesia, or dyskinesia. At peak stress, 466 of the 612 segments (76%) could be analyzed during conventional RUDE. With contrast-enhanced RUDE, the number of available segments increased to 553 (90%). The image quality index during conventional RUDE was 2.2, whereas with contrast-enhanced RUDE, it was 3.1. With conventional RUDE, 2 independent observers agreed on the diagnosis of myocardial ischemia in 85 of 108 coronary territories (79%, kappa = 0.26). With contrast-enhanced RUDE, agreement increased to 95 of 108 coronary territories (88%, kappa = 0.59). Study agreement on myocardial ischemia was present in 26 of 36 studies (72%, kappa = 0.43) with conventional RUDE and in 32 of 36 studies (89%, kappa = 0.77) with contrast-enhanced RUDE. In conclusion, during stress RUDE, contrast-enhanced imaging significantly decreases the number of poorly visualized myocardial segments and improves interobserver agreement for the diagnosis of myocardial ischemia. (c) 2007 Elsevier Inc. All rights reserved.