[Comparison of the echo-dobutamine-atropine test and ergometric test in the diagnosis of coronary disease]

Abstract

Background: A prospective study has been done on 46 patients with suspected coronary artery disease (CAD). They had no history of myocardial infarction (MI) and a normal basal kinetic echocardiography. This was done in order to evaluate the overall accuracy of dobutamine-atropine stress echocardiography (DAS) compare to exercise stress test (ET) for the diagnosis of CAD.

Methods: All the patients after suspension of coronary therapy, performed a casual sequence with both maximal or symptom limited exercise testing (treadmill-Bruce protocol) and DAS. The dobutamine has been given while monitoring systemic blood pressure, electrocardiography and echocardiography in steps of 10 mcg/kg/min' per 3 min' up to a maximum of 40 mcg/kg/min'. Atropine has been added (0.25-1 mg) in patients who did not reach the theoretical maximal cardiac frequency. The test is considered positive when kinetic segmental left ventricular dysfunction appeared. CAD was defined as 50% luminal area stenosis in at least 1 coronary artery at coronary angiography.

Results: Significant CAD was present in 27/46 patients (59%). Compared with ET, DAS had significantly higher sensitivity (59% vs 92%, p = 0.01). The different sensibility between the two tests was higher on these patients with a 1 vessel disease (40% vs 86%, p = 0.02). There were no significant differences in specificity among the two tests (79% vs 84%, respectively). Differences in overall accuracy between ET and DAS were significant (67% vs 89%, p = 0.02).

Conclusions: The results of our study show that the DAS is a safe and feasible technique with high sensibility (especially in patients with single CAD) and specificity. This is a valid alternative to the traditional ET, especially for these patients unable to exercise or these who are poorly motivated to achieve a work load sufficient to make the test interpretable.