[Effect of the use of echoenhancers on interobserver variability in dobutamine stress echocardiography]

Dobutamine stress echocardiography is an accurate technique for the noninvasive diagnosis of coronary artery disease. However, interobserver variability is an important limitation of stress echocardiography. Image quality and echocardiographer experience have been described to influence interobserver agreement.

The aim of this study was to determine whether use of contrast agents during dobutamine stress echocardiography improves the agreement between an experienced and a unexperienced observer, and if learning period would be influenced by the use of contrast.

Two blind observers interpreted all the studies: one experienced echocardiographer (A) and one unexperienced observer (B) in this technique. The contrast agent Levovist/Levograf 2.5 g was administered by two bolus (at rest and at peak stress). In all cases, second harmonic imaging and stress digitalisation packs were used. The kappa test was used to determine interobserver agreement.

Fifty-two unselected consecutive studies in 51 patients were analyzed. Twenty-two studies were performed with contrast. The agreement between the experienced and the unexperienced observer was Kappa 0.58 and 0.52, with and without the use of contrast, with no statistically significant difference being archived.

The routine use of contrast provides better although not significant, interobserver agreement. However, this improvement is not sufficient to substitute specific training.