722-4 Comparison of Thallium Reinjection Scintigraphy to Dobutamine Echocardiography for Detecting Myocardial Viability

Only moderate degree of concordance has been reported between stress-redistribution-reinjection thallium scintigraphy (Th-R) and dobutamine echocardiography (DE) for the identification of myocardial viability after acute myocardial infarction (AMI). Th-R with rest-reinjection performed 4 hours after exercise testing and digitized 2-D ultrasound reconstruction of the left ventricle (2-D E) at baseline and after low-dose dobutamine (5–10 gamma/kg/min) infusion were compared in 30 pts within the third week after AMI. Both Th-R and 2-D E were interpreted in 16 segments/pt. 2-D E in each wall motion was scored from 1 (normal) to 4 (dyskinesia). Myocardial viability was identified on 2-D E wall motion improvement ≥ 1 grade from baseline to 2-D E performed at least 30 days after systematic revascularization procedure of the infarct-related artery. Of 157 segments with 2-D Ebaseline wall motion abnormalities, 62 segments showed reversible defect during Th-R and 41 a wall motion improvement during DE (concordance of 67%). Myocardial viability was identified after angioplasty (n = 25) or surgery In = 5) in 48 segments. Positive and negative predictive values (PPV and NPV) of Th-R and DE in the diagnosis of myocardial viability are depicted in the table. PPV NPV DE 92% 60% Th-R 75% 61% Conclusion Dobutamine echocardiography is slightly more accurate than Th-R to identify myocardial viability after acute myocardial infarction.