Prognostic value of dobutamine echocardiography in patients with high pretest likelihood of coronary artery disease

Abstract

To examine the value of transient regional asynergy on dobutamine stress echocardiography as a noninvasive predictor of future cardiac events, 51 symptomatic patients (aged 54 ± 9 years) with suspected coronary artery disease (CAD) were studied using an incremental regimen of 5, 10, 15 and 20 μg/kg/min. Pretest likelihood of CAD was (mean ± standard error of the percentage) 79.7 ± 5.6% before and 83.4 ± 5.2% after exercise electrocardiography using probability analysis based on age, sex and symptoms. Two-dimensional images were analyzed with reference to an 11-segment model and gave good interrater agreement. During 24 ± 4 months (range 19 to 32) of follow-up, 23 patients had events (1 myocardial infarction, 9 unstable angina, 10 coronary bypass surgery, 3 coronary angioplasty) and 28 were event free. Age, proportion with baseline asynergy and both pretest echocardiographic ejection fraction and its response to dobutamine were similar in these 2 groups (all p = not significant). Transient asynergy was seen in 17 of 23 patients (74%) with and 8 of 28 patients (29%) without events (p < 0.01); 5 of 6 patients (83%) with involvement of 3 segments had events. Myocardial infarction or unstable angina occurred in 8 of 25 (32%) with a positive and 2 of 26 (8%) with a negative stress echocardiogram (p < 0.05). Both exercise duration (389 ± 195 vs 517 ± 237 seconds, p < 0.05) and time to diagnostic ST-segment shift (291 ± 192 vs 447 ± 212 seconds, p = 0.05) were shorter in those with inducible asynergy. These data suggest that patients with probable CAD and a positive dobutamine echocardiogram are at higher risk of an adverse outcome. Dobutamine echocardiography may aid selection for coronary angiography and prognostic revascularization, particularly in patients unable to exercise.