Prognostic value of pharmacological stress echocardiography in patients with known or suspected coronary artery disease - A prospective, large-scale, multicenter, head-to-head comparison between dipyridamole and dobutamine test

OBJECTIVES - The study compared the prognostic value of dipyridamole and dobutamine stress echocardiography in patients with known or suspected coronary artery disease. BACKGROUND - Extensive information is available on the relative diagnostic accuracy of the two tests assessed in a head-to-head fashion, whereas comparative data on their prognostic yield are largely preliminary to date. METHODS - Dipyridamole (up to 0.84 mg/kg over 10 min) atropine (up to 1 mg over 4 min) (DIP) and dobutamine (up to 40 ?g/kg/min)-atropine (1 mg over 4 min) (DOB) stress tests were performed in 460 patients with known or suspected coronary artery disease. Patients were followed up for 38 ± 21 months. RESULTS - The DIP was negative in 253 and positive in 207 patients. The DOB was negative in 242 and positive in 218 patients. During the follow-up, there were 80 cardiac events. For all cardiac events, the negative and positive predictive value were 83% and 17% for DOB, 84% and 19% for DIP, respectively (p = NS). Considering only cardiac death, by univariate analysis Wall-Motion Score Index (WMSI) at DIP peak dose (chi-square 13.80, p < 0.0002) was the strongest predictor, followed by WMSI DOB (?2 = 8.02, p < 0.004) and WMSI at rest (?2 = 6.85, p < 0.008). By stepwise analysis, WMSI at DIP peak dose was the most important predictor (RR [relative risk] 7.4, p < 0.0001). CONCLUSIONS - In patients at low-to-moderate risk of cardiac events, pharmacological stress echocardiography with either dobutamine or dipyridamole allows effective and grossly comparable, risk stratification on the basis of the presence, severity and extension of the induced ischemia.