Comparative study of dobutamine stress echocardiography and dual single-photon emission computed tomography (Thallium-201 and I-123BMIPP) for assessing myocardial viability after acute myocardial infarction

Discordance between the I-123-labelled 15-iodophenyl-3-R, S-methyl pentadecanoic acid (BMIPP) and Tl-201 findings may indicate myocardial viability (MV). This study compared dobutamine stress echocardiography (DSE) and single-photon emission computed tomography (SPELT) using the dual tracers for assessment of MV and prediction of functional recovery after acute myocardial infarction (AMI). DSE and dual SPELT were studied in 35 patients after AMI, of whom 28 underwent percutaneous coronary intervention in the acute stage. Dual SPELT was performed to compare the defect score of BMIPP and Tl-201. The left ventricular wall motion score (WMS) was estimated during DSE and 6 months later to assess functional recovery of the infarct area. The rate of agreement of MV between dual SPELT and DSE was 89% (p<0.01), and the sensitivity and specificity of DSE for dual SPELT in MV assessment was 86% and 93%, respectively. The positive and negative predictive values for functional recovery by dual SPELT were 76% and 67%, respectively, and by DSE were 90% and 79%, respectively. Four of 5 patients with positive MV by dual SPELT, but without functional recovery, had residual stenosis of the infarct-related artery. The WMS and defect scores of BMIPP and Tl-201 were significantly smaller in patients with functional recovery than in those without. Assessment of MV using DSE concords with the results of dual SPELT in the early stage of AMI. DSE may have a higher predictive value for long-term functional recovery at the infarct area. However, a finding of positive MV by dual SPELT, without functional recovery, may indicate residual stenosis of the infarct-related artery, although the number of cases was small. Combined assessment by dual SPELT and DSE may be useful for detecting MV and jeopardized myocardium. Furthermore, the results suggest that functional recovery of dysfunctional myocardium may depend on the size of the infarct and risk area.