Safety, feasibility, and prognostic implications of pharmacologic stress echocardiography in 1482 patients evaluated in an ambulatory setting

Background The outpatient prognostic assessment of coronary artery disease (CAD) by exercise electrocardiography has limitations, including the feasibility of the test and its low positive predictive value in several clinical conditions, In the current study we investigated the safety, feasibility, and prognostic value of pharmacologic stress echocardiography in a large cohort of ambulatory patients. Methods The study group was mode of 1482 ambulatory patients (969 men, aged 60 +/- 10 years) who underwent stress echocardiography with either dipyridamole (n = 846) or dobutamine (n = 636) for evaluation of suspected or known stable CAD. The pretest likelihood of CAD was intermediate (<70%) in 709 patients and high (<greater than or equal to>70%) in 773 patients. Results There was no complication during the dipyridamole test, whereas 2 ischemia-dependent, sustained ventricular tachycardias occurred during the dobutamine test. Limiting side effects were observed in 2% of dipyridamole and in 3% of dobutamine stresses. The echocardiogram was positive in 459 patients. During a mean follow-up of 28 +/- 24 months, 58 patients died, 33 had a nonfatal myocardial infarction, and 158 underwent early (less than or equal to3 months) and 64 late (>3 months) revascularization. Multivariate predictors of hard events (death, infarction) were positive echocardiographic results (hazard ratio [HR] 2.9) and resting wall motion score index (WMSI) (HR 2.3). In considering major events (death, infarction, late revascularization) as end points, positive echocardiographic result (HR 4.3), scar (HR 2.2), and resting WMSI (HR 1.7) were independent prognostic predictors. The 5-year survivor rates for the ischemic and nonischemic groups were, respectively, 80% and 91% (HR 3.6, 95% confidence interval [CI] 3.8-8.4; P < .0001) considering hard cardiac events and 65% and 88% (HR 2.6, 95% Cl 2.1-5.9; P < .0001) considering major events. Multivariate predictors of major events were positive echocardiographic results (HR 8.2) and male sex (HR 2.5) For the intermediate-risk group and positive echocardiographic results (HR 2.9), resting WMSI (HR 1.8), and prior Q-wave myocardial infarction (HR 1.8) for the high-risk group. Conclusions Pharmacologic stress echocardiography is safe, highly feasible, and effective in prognostic assessment of ambulatory patients when both a general population and groups selected on the basis of pretest likelihood of CAD are analyzed. It represents a valid complementary tool to exercise electrocardiography for prognostic purposes in outpatients.