Dobutamine stress echocardiography for assessment of myocardial viability and ischemia in acute myocardial infarction treated with thrombolysis

Abstract

To evaluate the role of dobutamine echocardiography for early assessment of myocardial viability and ischemia in acute myocardial infarction (MI), 59 patients with thrombolyzed acute MI underwent low- (5–10 μg/kg/min, 8 patients) and high-dose (20–40 μg/kg/min, 51 patients) dobutamlne echocardiography at a mean of 8 ± 4 days after acute MI. Myocardlal viability in the infarct zone was documented in 43 of 59 (73%) patients (group 1), in whom mean asynergy score index decreased from 1.6 ± 0.3 at baseline to 1.3 ± 0.2 (p < 0.001), after low-dose dobutamine. No viability was present in 16 of 59 (27%) patients (group 2). At follow-up, recovery of regional contractile function was observed in group 1 (asynergy score index decreased from 1.6 ± 0.3 to 1.4 ± 0.3; p < 0.001), but not in group 2 patients. Sensitivity, specificity, and negative and positive predictive values of low-dose dobutamine echocardiography in predicting spontaneous recovery of function were 79%, 68%, 50%, and 89%, respectively. Of the 51 patients who underwent high-dose dobutamine, 26 of 36 (72%) group 1 patients showed a deterioration of contractility in the infarct zone indicative of myocardlal ischemia compared with only 1 of 15 (7%) group 2 patients. At follow-up, recovery of regional function was greater in patients with no evidence of myocardlal ischemia at high doses than in those with an ischemic response. Thus, in patients with thrombolyzed acute MI, dobutamine echocardiography is a useful clinical tool for detection of myocardlal viability and ischemia in the infarct zone and for identification of patients with jeopardized myocardium in the area at risk who can benefit from myocardlal revascularlzation.