Abstract 2344: The Effect of Beta-Blocker Therapy on Prognostic Value of Dobutamine Stress Echocardiography with Early Injection of Atropine
Although withdrawn of beta-blockers (BB) is recommended before stress test, this practice is not always followed. New protocols of early injection of atropine during dobutamine stress echocardiography (EA-DSE) are recently proposed.
Objective: To determine the effect of BB on the prognostic value of EA-DSE.
Methods: We studied 693 patients (pts) who underwent EA-DSE (started at 20 μg/Kg/min of dobutamine) for known or suspected coronary artery disease (CAD). Among them, 262 (38%) were using BB, not discontinued before test. Pts were followed for a median of 20 months (up to 65 months).
Results: EA-DSE was negative in 448 (65%), positive in 172 (25%) and inconclusive in 73 (10%) pts due to chronotropic incompetence. 80 events occurred(27 deaths, 12 myocardial infarction (MI), 41 revasculariza-tions). By univariate analysis the predictors of events were diabetes (p=0.008), previous coronary bypass graft (p<0.001), male sex (p=0.011), BB (p=0.04), previous MI (p=0.009), ejection fraction<50% (p<0.001), and positive EA-DSE (p<0.001). By multivariate analysis the only independent predictor was positive EA-DSE (OR 4.99, 95% CI 2.98 – 8.35;p<0.001). Two-year event rate in pts without BB and negative EA-DSE was 4%, with BB and negative EA-DSE was 7%, without BB and positive EA-DSE was 34% and with BB and positive EA-DSE was 24% (p<0.001, Figure⇓).
Conclusion: Detection of ischemia during EA-DSE was an independent predictor of events. Patients with negative EA-DSE under BB had a slightly higher event rate than those without BB. Patients with a positive EA-DSE under BB had better prognosis than those without therapy, probably due to the therapeutical effects of BB in pts with CAD.