The value of dobutamine stress echocardiography in predicting clinical improvement following coronary artery bypass grafting in patients with left ventricular systolic dysfunction

Abstract

Background: Recent years have seen an increasing number of patients with multivessel coronary artery disease and left ventricular systolic dysfunction being qualified for cardiac surgery. Identification of patients who are likely to benefit most from revascularisation procedures poses a considerable problem. The aim of the study was to assess the value of dobutamine stress echocardiography in predicting the clinical course following coronary artery bypass grafting (CABG) in patients with ischaemic left ventricular dysfunction.
Methods: Fifty patients with multivessel coronary artery disease and reduced left ventricular ejection fraction (LVEF < 40%) who were qualified for CABG were included in the study. Resting echocardiography and a small-dose (5–10 µg/kg/min) dobutamine test were performed before the procedure. Subsequent tests were repeated after the procedure and at 3.6 and 12 months. A combined endpoint of death, repeat hospitalisations, NYHA stage, severity of angina and left ventricular systolic function was evaluated.
Results: Two factors were found to affect the prognosis adversely following CABG in both univariate and multivariate analysis: a history of hypertension (p = 0.039, OR 4.9, 95% CI 1.4-17.1) and lack of improvement in contractility in at least 4 segments during the dobutamine test (p = 0.0003, OR 37.2, 95% CI 6.3-218.4). An improvement in contractility in at least 4 segments of the left ventricle is the most important prognostic factor.
Conclusions: The results of the dobutamine stress test have a more potent prognostic value than clinical or demographic parameters in predicting clinical improvement. Patients with negative results of the test represent the group with the gravest prognosis. (Cardiol J 2007; 14: 174-179)