Comparison between Exercise Stress Test and Dobutamine Electrocardiographic Stress Test to Detect Coronary Disease in Patients with Non-Complicated Acute Myocardial Infarction

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Abstract

Introduction

Although exercise stress test (EST) is the most com-mon way of assessing risk stratification after acutemyocardial infarction, between 20 to 40% of pa-tients are not able to perform it because of cardio-vascularor non cardiovascular reasons. The dobu-tamine electrocardiographic stress test (DEST) hasbeen proposed as a simple alternative method forthese patients. However, several aspects ofthis testare still unexplored.

Objective

To compare the ability of the dobutamine electrocardiographic stress test with the exercise stress test to detect coronary artery stenosis on coronary arteriography in a group of consecutive AMI patients.

Material and methods

Twenty eight consecutive patients with an uncomplicated AMI were studied (mean age 61 ± 10.6years; 75%males). EST, DEST and coronary angiography were performed between 4 to 7 days after AMI. The DEST was carried out with a dobutamine infusion of increasing steps of 5 minutes each, from 10 to 20, 30 and 40 mg/kg/min. If the expected heart rate was not achieved,1 mg atropine intravenously was added in the last stage.Sensitivity, specificity, positive predictive value and negative predictive value to detect one, two or three vessels disease on angiography were assessed forEST and DEST. In order to calculate the specificity estimates, seventeen patients admitted to the Coro-nary Care Unit because of chest pain with a normal coronary angiography were used as controls; these patients underwent EST and DEST as well.

Results

Coincidence between the result of EST and DEST (both positives or negatives) was obtained in 61%of patients. No differences were seen neither in mean heart rate nor double product between EST and DEST. A trend toward higher heat rate and double product was detected in those tests with positive results compared with the negative ones, both in EST and DEST. The ability to detect 1, 2 or3 vessels disease was similar between both tests, showing equally a high negative predictive value (DEST: 0.92; EST: 0.90; p = non significant).

Conclusions

In this preliminary presentation, the DEST showed similar value to the EST to predict angiographically determined coronary lesions. The DEST may be an alternative test in patients who can not perform exercise.