Backgrounds: The aim of the study was to assess the relative prognostic accuracy of dobutamine echocardiography (TED) vs maximal bicycle exercise electrocardiography (TE) in patients with proven coronary artery disease.
Methods: One hundred and thirty consecutive patients (70 patients with uncomplicated recent myocardial infarction, 19 asymptomatic patients with previous myocardial infarction and 41 patients with stable angina pectoris and previous myocardial infarction or previous myocardial revascularization procedure) underwent TED (incremental dobutamine infusion: 5 to 40 ncg/kg/min, continued with atropine 0.25 to 1 mg iv if necessary) and TE on different days and in random order. Criteria for positivity were: new or worsening regional dyssynergy for TED; ST segment shift > or = 1 mm from baseline for TE. End points were defined as spontaneous events (cardiac death, myocardial infarction and unstable angina) and total events (spontaneous events plus myocardial revascularization procedures).
Results: During 15.4 +/- 7.9 (range 1-33) months of follow-up, 33 events occurred: cardiac death (1), myocardial infarction (4) unstable angina (21) myocardial revascularization (7). Sensitivity, specificity, positive and negative predictive value, prognostic accuracy were similar for TED and TE (P = NS). Cumulative event-free survival curves as a function of TED and TE results were both statistically significant. A Cox stepwise regression analysis identified TED positivity obtained without atropine administration as the best predictor of spontaneous and total events (Odds ratio 5.33 and 4.38, respectively). Cumulative survival curves obtained by the combination of TED and TE results were statistically different (P < 0.05 and P < 0.001 for spontaneous and total events, respectively) and showed a poor clinical outcome in patients with both tests or only TED positive. TED correctly predicted clinical outcome in 24/39 patients in whom there was disagreement between the two tests.
Conclusions: In patients with proven coronary artery disease, TED and TE have a similar accuracy for predicting clinical outcome. Where a discrepancy is seen between the two tests, TED appears to have a slightly higher prognostic value.