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 feasib ility 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 co hort 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 dipyrid amole (n = 846) or dobutamine (n = 636) for evaluation of suspected or know n 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 i schemia-dependent, sustained ventricular tachycardias occurred during the d obutamine test. Limiting side effects were observed in 2% of dipyridamole a nd in 3% of dobutamine stresses. The echocardiogram was positive in 459 pat ients. During a mean follow-up of 28 +/- 24 months, 58 patients died, 33 ha d a nonfatal myocardial infarction, and 158 underwent early (less than or e qual to3 months) and 64 late (>3 months) revascularization. Multivariate pr edictors 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 revasculari zation) as end points, positive echocardiographic result (HR 4.3), scar (HR 2.2), and resting WMSI (HR 1.7) were independent prognostic predictors. Th e 5-year survivor rates for the ischemic and nonischemic groups were, respe ctively, 80% and 91% (HR 3.6, 95% confidence interval [CI] 3.8-8.4; P < .00 01) 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 eve nts 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 o f CAD are analyzed. It represents a valid complementary tool to exercise el ectrocardiography for prognostic purposes in outpatients.