PROGNOSTIC VALUE OF HIGH-DOSE DIPYRIDAMOLE-ECHOCARDIOGRAPHY IN PATIENTS WITH CHRONIC CORONARY-ARTERY DISEASE AND PRESERVED LEFT-VENTRICULARFUNCTION

Objectives. The prognostic value of dipyridamole echocardiographywas a ssessed in patients with chronic coronary artery disease and preserved left ventricular function. Background. Few data are available on the prognostic value of dipyridamole echocardiography in patients with a l ow risk of cardiac events. Methods. Two hundred sixty-eight consecutiv e patients with stable, proven or suspected coronary artery disease an d ejection fraction greater than or equal to 0.40 underwent high dose (up to 0.84 mg/kg body weight) dipyridamole echocardiography, In 204 p atients definite exercise electrocardiographic (EGG) results were also available. Results. During a mean (+/-SD) follow-up period of 16 +/- 8 months (range 6 to 36), 33 spontaneous events occurred: 15 ''hard'' events (cardiac death [n = 6], myocardial infarction [n = 9]) and 18 ' 'soft'' events (unstable angina). Events occurred more frequently in p atients with positive findings on dipyridamole echocardiography (59% v s, 3%, p < 0.001; hard events 24% vs. 2%, p < 0.01), A positive respon se at the low dose (up to 0.56 mg/kg) identified patients with a high incidence of hard events (7 of 16 patients, sensitivity 50%, specifici ty 96%), In patients with an exercise EGG, a comparable sensitivity fo r cardiac events was found (89% vs, 93%, p = NS), but dipyridamole ech ocardiography was more specific (91% vs, 61%, p < 0.01). A positive re sponse on the low work load exercise ECG (<8 min) and a positive respo nse to low dose dipyridamole echocardiography had similar accuracy (82 % vs. 90%, p = NS), Cox analysis identified dipyridamole echocardiogra phy as the best predictor of cardiac events (odds ratio [OR] 20.9, 95% confidence interval [CI] 10.8 to 37.9); the highest risk of hard even ts was found in patients with a positive response to low dose dipyrida mole echocardiography (OR 25.4, 95% CI 12.2 to 54.1). Conclusions. In patients with chronic coronary artery disease and a low incidence of c ardiac events, dipyridamole echocardiography was effective in prognost ic stratification, and positive low work load exercise ECG results wer e a reliable predictor of subsequent events. Consequently, dipyridamol e echocardiography should be considered a complementary tool in the pr esence of high work load positivity or ambiguous exercise ECG results.