To determine the value of negative dobutamine stress echocardiography (DSE) results in predicting subsequent long-term cardiac event rates, we retrospectively reviewed all dobutamine stress echocardiograms performed at our institution over a 3-year period (1992-1994). Follow-up was accomplished through the completion of a detailed questionnaire compiled from data obtained through chart review and direct telephone contact. Information regarding death also was determined by referencing patient data with mortality data available on the World Wide Web. Event rates were determined for hard (myocardial infarction [MI] or cardiac death) and soft (hospitalization for angina and/or congestive heart failure, coronary angioplasty, or coronary bypass surgery) cardiac events occurring after the negative DSE results for up to 7 years after the test. Negative test results were defined as those showing no new or worsening wall motion abnormalities after either a normal resting echocardiogram (normal-negative [NN]) or an abnormal segmental resting echocardiogram (fixed-negative [FN]).
Results: Of the 346 interpretable tests, 224 were negative for inducible wall motion abnormalities, with 171 NN and 53 FN. In the NN group, the MI rate was 1.5% per patient/year, and the mortality rate was 0.13% per patient/year. In the FN group, the MI rate was 0.7% per patient/year, and the mortality rate was 0% per patient/year.
Conclusions: DSE results in both NN and FN groups predict a very low subsequent hard event rate and mortality for up to 5 years after the test.