Dobutamine-transesophageal echocardiography versus dipyridamole thallium-201 scintigraphy for assessment of myocardial viability

ABSTRACT

Dipyridamole Thallium-201 scintigraphy have been widely used to differentiate between scar tissue and viable but not functioning myocardium and showed superiority over dobutamine stress echo-cardiography. The development of transesophageal echocardiogram [TEE] may overcome many of transthoracic limitations. To compare dobutamine stress TEE and Dipyridamole thallium scintigraphy in detection of myocardial viability. The study included 27 patients with coronary artery disease [CAD] and severe segmental wall motion abnormalities [SWMA] on resting echocardiogram who were scheduled for revascularization either through angioplasty or bypass surgery [CABG]. Dobutamine-TEE and dipyridamole thallium scintigraphies were done within 5 to 7 days before revascularization. Post-revascularization resting echocardiography was done 14 to 21 days to assess any improvement of SWMA as a sign of myocardial viability. Although the sensitivity of dobutamine TEE to detect myocardial viability was higher than that of thallium scintigraphy [89% vs. 72% respectively] but it did not reach statistical significance [P=0.06]. However, the specificity of TEE was significantly higher than that of scintigraphy [83% vs. 67%, P=0.04] and the total diagnostic accuracy of dobutamine TEE to detect myocardial viability was significantly higher than that of dipyridamole thallium scintigraphy [88% vs. 71% p = 0.05]. In the presence of severe SWMA, dobutamine TEE could detect myocardial viability more frequently than dipyridamole thallium scintigraphy