Value of dobutamine stress echocardiography in determining the prognosis of patients with known or suspected coronary artery disease

Although the accuracy of dobutamine stress echo (DSE) for detecting coronary artery disease (CAD) has been established, its role in determining prognosis is less well defined. The purpose of this study was to evaluate the prognostic significance of DSE in patients with known or suspected CAD. Follow-up was obtained on 291 patients an average of 15 months after clinically indicated DSE. Studies were stratified with respect to resting and inducible wall motion abnormalities into 1 of 4 responses: normal, ischemic, fixed, and mixed. Hard end points of nonfatal myocardial infarction and cardiac death were tabulated for outcome. Statistically significant differences in the incidence of hard cardiac end points were noted for 2 of 4 DSE responses. A normal DSE was associated with a statistically lower likelihood of a hard cardiac event than was a DSE demonstrating resting or inducible abnormalities (p = 0.001). DSE with a mixed response (resting abnormality with additional inducible ischemia) was associated with a higher likelihood of cardiac events by multivariate analysis (p = 0.003). By multiple logistic regression analysis of dobutamine response, age, and cardiac risk factors, only a mixed response on DSE was independently associated with the occurrence of a hard cardiac event in the follow-up period. In addition, left ventricular dysfunction on the resting echocardiogram was associated with a worse prognosis in patients with major noncardiac disease. We conclude that dobutamine response is an independent predictor of cardiac events compared with traditional risk factor analysis and that DSE can identify high- and low-risk subsets of patients with known or suspected CAD.